BERKELEY
lERARY

WVEBSM7 or

CALIFOBMrA

FROM THE OPTOMCTRIC LIRRARY
OF

MONROE JEROME HIRSCH

J^/l

THE LIBRARY

THE UNIVERSITY

OF CALIFORNIA

GIVEN WITH LOVE TO THE

OPTOMETRY LIBRARY

MONROE J. HIRSCH, O.D., Ph.D.

DISEASES OF THE EYE

SWANZY'S HANDBOOK

DISEASES OF THE EYE

AND THEIR

TREATMENT

EDITED BY

LOUIS WERNER, M.B., F.R.C.S.L, Sen. Mod. Univ. Dub.

SURGEON TO THE ROYAL VICTORIA EYE AND EAR HOSPITAT,

OPHTHALMIC SURGEON TO THE MATER HOSPITAL, PROFESSOR OF

OPHTHALMOLOGY, UNIVERSITY COLLEGE, DUBLIN, AND EXAMINER IN

OPHTHALMOLOGY, DUBLIN UNIVERSITY

ELEVENTH EDITION
WITH ILLUSTRATIONS

LONDON

H. K. LEWIS, 136 GOWER STREET, W.C.

1915

OPTOMETRY

"(f^ dC

London

H. K. LEWIS, 136 GOWER STREET, W.C.

PREFACE

oero

In this edition, the first which has appeared since the death of my
esteemed friend and colleague the late Sir Henry Swanzy, I have
carefully avoided making any change in the general plan or
character of the book.

The text has again been completely revised and brought up to
date, with the result that a considerable amount of new matter has
been incorporated, but without any notable increase in the number
of pages.

The Chapter on the Pupil, which was omitted in the last edition,
has now been restored to its place. In the chapter on Glaucoma,
the trephine operation has been dealt with in greater detail, and a
description of Schiotz's tonometer has been added. The Diseases
of the Retina have been to some extent re-arranged ; Hsemorrhagic
Retinitis is no longer treated as a separate entity, but is referred to
under Thrombosis of the Retinal Vein, while a separate paragraph
is allotted to Retinal Haemorrhages in general ; Angio-sclerosis and
obstruction of the Retinal Circulation receive more attention than
heretofore, and Capillary Angiomatosis of the Retina and Massive
Exudation are briefly described.

The chapter on Nystagmus has been altered and amplified, and
now includes a brief account of Vestibular Nystagmus.

Numerous minor improvements and additions have been made,
amongst which may be mentioned the introductory paragraphs to
Chapters V, VI, X, and XIX, the articles on CEdema of the Eyelids,
Artificial Eyes, Maddox's Wing Test for Heterophoria, etc. Many
new illustrations have also been added.

I have again to thank Dr. Kathleen Lynn for the care and trouble
which she has taken in the preparation of the index.

L. Werner.
31, Merrion Square,
Dublin.

PREFACE TO THE TENTH EDITION

In the present edition, as in the previous ones, the endeavour has
been to keep the book abreast of modern ophthalmology, in so far
as this is possible in a work of its size, mainly intended for students.
The amount of text is about the same as before, although, in con-
sequence of an alteration in the shape of the book, the number
of pages is less. The chapters are differently arranged, with the
result that the earlier ones now treat of the normal eye and its
functions, and the methods for examining them. The book has
been thoroughly revised throughout, obsolete matter having been
discarded, while new developments have been introduced. The
book now, for the first time, contains coloured figures, to the number
of twenty-one, from original paintings by one of us (L. W.), and
it is believed that these w^ill prove helpful to the student.

Our thanks are due to Dr. Kathleen Lynn for the great pains
she has taken in the preparation of the index.

We desire also to express our thanks to Mr. H. K. Lewis for
the care he has given to the production of the book and for his
readiness to carry out all our suggestions.

H. R. S.
L. W.

Dublin,

CONTENTS

CHAPTER I.

PAGE

Preliminary Note on the Clinical Examination of Eye Patients . 1

Optical Structure and Functional Examination of the Eye . . 2

Refraction — Accommodation — The Mechanism of Accommodation
— The Far Point and the Near Point — The Amplitude and
Range of Accommodation — Connection between Accommodation
and Convergence (Relative Accommodation)^ — Convergence —
Range and Amplitude of Convergence ..... 4

The Sense of Sight (Light- Sense, Colour- Sense, Form- Sense) . . 10

The Field of Vision — Perimetry — Pathological Defects in the Field
of Vision — Perception of Colours in the Periphery of the Field
• — Perception of Form in the Periphery of the Field . . .17

CHAPTER 11.

THE OPHTHALMOSCOPE.

Laws of Reflection— Images formed by Plane and Concave Mirrors

— How to distinguish Plane and Concave Mirrors . . .26

The Ophthalmoscope — Why Necessary — Helmholtz's Ophthalmo-
scope — Modern Ophthalmoscope — Direct Method — Indirect
Method 27

Detection of Opacities in the Refractive Media by aid of the Oph-
thalmoscope ......... 35

The Normal Fundus Oculi as seen with the Ophthalmoscope — The
Optic Disc or Optic Papilla — The Retina — The- Macula' Lutea —
The General Fundus Oculi — The Retinal Vessels ... 36

CHAPTER III.

DISEASES OF THE CONJUNCTIVA.

Preliminary Note — The Examination of the Conjunctiva . . 42

Hypersemia — Conjunctivitis in General (Causes — Diagnosis —
Varieties) — Bacteriology of Conjunctivitis — Catarrhal, Simple,
Acute, or Muco-purulent Conjunctivitis — Diplobacillary or

CONTENTS

Angular Conjunctivitis — Chronic Simple, or Chronic Ca-
tarrhal, Conjunctivitis — Acute Blennorrhoea of the Conjunctiva,
or Purulent Ophthalmia — Membranous Conjunctivitis (Croupous
and Diphtheritic) — Hay Fever — Trachoma. Granular Con-
junctivitis, or Granular Ophthalmia (Acute and Chronic) — Fol-
licular Conjunctivitis — Tubercular Disease — Parinaud's Con-
junctivitis — Ophthalmia Nodosa — Sporotrichosis — Lupus —
Syphilis — Ulcers of the Conjunctiva — Spring Catarrh, or Vernal
Conjunctivitis — Pemphigus — Conjunctivitis Petrificans — Sub-
conjunctival Ecchymosis — Subconjunctival Serous Effusion, or
Chemosis — Emphysema — Injuries — Degenerative Diseases —
Pinguecula — Epithelial Plaques — Pterygium — Lithiasis — Xerosis
or Xerophthalmia — Hj^aline, Colloid, and Amyloid Degeneration 93
Cysts — Simple Cysts — Sub-conjunctival Cysticercus . . .98

Tumours — Dermo-Lipoma — Osteoma — Naevus, or Mole — Hseman-
gioma — Polypus and Granuloma — Lj^iiphoma — Papilloma, or
Papillary Fibroma — Epithelioma — Sarcoma — Tumours of the
Caruncle 99

CHAPTER IV.

PHLYCTENULAR CONJUNCTIVITIS AND KERATITIS.

Solitary, or Simple, Phlycten of the Conjunctiva — Multiple, or
Miliary, Phlyctens of the Conjunctiva — Primary Phlyctenular
Keratitis 102

CHAPTER V.

DISEASES OF THE CORNEA.

Introduction . . . . . . . . . .110

Clinical Methods of Examining the Cornea . . . . .110

Inflammations of the Cornea — (a) Ulcerative Inflammations — Simple
Ulcer — Deep Ulcer — Serpiginous Ulcer — Marginal Ring Ulcer —
Diplobacillus Ulcer — Rodent Ulcer — Keratomalacia — Neuro-
paralytic Keratitis — Herpes Corneae Febrilis — Dendriform
Keratitis — Bullous Keratitis — Filamentary Keratitis — Keratitis
Aspergillina . . . . . . . . .112

(6) Non-Ulcerative Inflammations — Abscess — Ring Abscess —
Syphilitic Diseases (Diffuse Interstitial Keratitis — Specific
Punctiform Interstitial Keratitis — Gumma) — Nodular, and
Reticular Keratitis — Discoid Keratitis — Tubercular Keratitis —
Keratitis Punctata — Sclerotising Opacity — Ribandlike Keratitis
— Superficial Epithelial Dystrophy . . . . .136

Ectasies of the Cornea — Staphyloma — Conical Cornea — Atrophic

Marginal Degeneration . . . . . . . .146

Tumours of the Cornea . . . . . . . .153

CONTENTS

Injuries of the Cornea — Foreign Bodies — Losses of Substance, or
Abrasions — Recurrent Abrasion, or Disjunction — Haemorrhagic
Discoloration — Blows — Injuries with Caustic Substances — Per-
forating Injuries . . . . . . . . .153

Opacities of the Cornea — Nebula, Macula, Leucoma — Arcus Senilis 160

CHAPTER VI.

DISEASES OF THE SCLEROTIC.

Introductory — Episcleritis — Deep Sclerotis — Gumma — Tubercle —

Brawny Scleritis . . . . . . . .164

Tumours — Pigment Spots . . . . . . . .168

Injuries . . . . . . . . . . .168

Staphyloma — Coloboma — Congenital Defects . . . .171

CHAPTER VII.

DISEASES OF THE UVEAL TRACT.

Inflammations of the Iris, or Iritis — Acute Iritis . . , .173

Syphilitic — Gonorrhoeal — Tubercular — Rheumatic . . .177

Chronic Iritis or Irido-cyclitis . . . . . . .183

Inflammations of the Ciliary Body, or Cyclitis — Acute — Chronic —

Syphilitic — Gumma — Tubercular Cyclitis . . . .187

Inflammations of the Chorioid, or Chorioiditis — Disseminated —
Central Senile Guttate — Central — Syphilitic Chorioido-Re-
tinitis — Purulent Chorioiditis . . . . . .189

Sympathetic Ophthalmitis and Sympathetic Irritation — Injuries
of the Iris — Foreign Bodies — Iridodialysis — Retroflexion — Rup-
ture of the Sphincter — Dehiscence — Aniridia — Mydriasis and
Miosis • . 193

Injuries of the Ciliary Body — Punctured Wounds and Foreign

Bodies . . . . . . . . . .214

Injuries of the Chorioid — Foreign Bodies — Incised Wounds — Rupture

— Extravasation of Blood . . . . . . .214

New Growths of the Iris — Cysts — Granuloma — Solitary Tubercle —

Sarcoma — Carcinoma — Ophthalmia Nodosa . . . .216

New Growths of the Ciliary Body — Sarcoma — Myosarcoma — Car-
cinoma . . . . . . . . . .217

New Growths of the Chorioid — Sarcoma — Carcinoma — Tubercle —

Sarcoma .Carcinomatosum, Osteo-Sarcoma, and Lymphoma . 217

Other Diseases of the Chorioid — Posterior Staphyloma — Detach-
ment — Central Senile Areolar Atrophy . . . . .221

Malformations of the Iris — Heterophthalmos — rCorectopia — Polycoria

— Persistent Pupillary Membrane — Coloboma . . .223

Malformations of the Chorioid — Coloboma — Alterations in the Colour

of the Iris — Albinismus ....... 224

Operations on the Iris . . . . . . . .225

CONTENTS

CHAPTER VIII.

THE PUPIL.

pa(;e
Contraction of the Pupil — Dilatation of the Pupil — Action of Mydri-
atics — Action of Miotics . . . . . . .229

CHAPTER IX.

GLAUCOMA.

Primary Glaucoma — Schiotz Tonometer — Chronic Simple Glaucoma —
Acute Glaucoma — Subacute Glaucoma — Etiology — Pathology —
Treatment .......... 235

Secondary Glaucoma — Haemorrhagic Glaucoma .... 258

Congenital Glaucoma, or Hydrophthalmos ..... 260

CHAPTER X.

DISEASES OF THE CRYSTALLINE LENS.

Introduction — Complete Cataracts — Senile Cataract — Complete Cata-
ract of Young People — Diabetic Cataract — Glass-Blower's
Cataract — Black Cataract . . . . . . .201

Partial Cataracts — Central Cataract — Zonular, or Lamellar, Cataract
— Punctate Cataract — Anterior Polar, or Pyramidal Cataract —
Fusiform, or Spindle-shaped Cataract — Posterior Polar Cataract 269
Secondary Cataract — Posterior Polar Cataract — Total Secondary

Cataract .......... 272

Capsular Cataract ......... 273

Traumatic Cataract . . . . . . . . .273

Operations for Cataract — Extraction — Linear Extraction — The
Combined Operation — Extraction without Iridectomy — Ex-
traction in the Capsule . . . . . . .275

Discission ........... 293

Dislocation of the Lens . . . . . . . .294

Congenital Defects of the Lens — Ectopia — Coloboma — Lenticonus

Aphakia ........... 295

CHAPTER XL

DISEASES OF THE VITREOUS HUMOUR.

Purulent Inflammation — Other Inflammatory Affections — Haemor-
rhage — Muscae Volitantes — Synchysis — Synchysis Scintillans . 298

Foreign Bodies — Rontgen Rays for Detection of Foreign Bodies —

The Sideroscope — Removal of Foreign Bodies — The Magnet . 303

Cysticercus — Blood Vessels — Persistent Hyaloid Artery . . .311

CONTENTS

CHAPTER XII.

DISEASES OF THE RETINA.

PAGE

Alterations in the Retinal Circulation — Hyperemia and Anaemia —

Pulsation of Vessels . . . . . . . .313

Inflammations — Retinitis — Syphilitic, Albuminuric, Diabetic, Leu-

coemic, Metastatic . . . . . . . .314

Retinal Haemorrhages and Allied Diseases — Retinitis Proliferans —
Retinitis Exudativa — Retinitis Circinata — Capillary Angio-
matosis .......... 320

Diseases of the Retinal Vessels — -Sclerosis — Obstruction of the Central
Artery — Tlirombosis of the Central Artery — Thrombosis of the
Retinal Vein — Quinine Amaurosis — Amaurosis from Filix Mas 323

Atrophies, or Degenerations — Retinitis Pigmentosa — Retinitis

Punctata Albescens — Gyrate Atrophy . . . . .328

Injury of the Retina by Strong Light — Direct Sunlight — Snow-
Blindness — Electric Light . . . . . . .331

Tumours of the Retina — Glioma — Tubercle ..... 334

Parasitic Disease of the Retina — Cysticercus . . . . .335

Detachment of the Retina . . . . . . . .336

Traumatic Affections of the Retina — Ana?sthesia — Commotio Re-
tinae — ' Holes ' at the Macula Lutea ..... 339

CHAPTER XIII.

DISEASES OF THE OPTIC NERVE.

Optic Neuritis (Papillitis), due to : Cerebral Tumours — Tubercular
Meningitis — Hydrocephalus — Tumours of the Orbit — Inflam-
matory Processes in the Orbit — Exposure to Cold — Suppression
of Menstruation — Chlorosis — Syphilis — Rheumatism — Lead-
Poisoning — Peripheral Neuritis — Disseminated Sclerosis — Tabes
Dorsalis — Hereditary Predisposition — Certain Fevers . .341

Retro-Bulbar Optic Neuritis — Optic Neuritis Associated with Per-
sistent Cerebro- Spinal Rhinorrhoea . . . . .347

Toxic Amblyopia (Axial Neuritis) ...... 349

Atrophy of the Optic Nerve, due to : Optic Neuritis — Pressure —
Embolism of the Central Artery — Syphilitic Retinitis — Retinitis
Pigmentosa — Chorioido-Retinitis ...... 353

Primary Atrophy, due to : Hereditary Predisposition, with Disease
of the Spinal Cord, as a Purely Local Disease, from Poisoning
with Organic Preparations of Arsenic ..... 354

Tumours of the Optic Nerve — Hyaline Outgrowths . . . 357

Injuries of the Optic Nerve ....... 357

Amblyopia due to Haemorrhages from the Stomach, Bowels, or Uterus

— Glycosuric Amblyopia ....... 357

CONTENTS

CHAPTER XIV.

PART I.

pa(;e

OCULAR DISEASES AND SYMPTOMS LIABLE TO ACCOMPANY FOCAL
DISEASE OF THE BRAIN.

Hemianopsia — Arrangement of the Cortical Visual Centres, their
Relations to the Retina, and the Course of the Optic Fibres
between these Two Points — Localisation of the Lesion in
Hemianopsia — Word -Blindness — Visual Aphasia — Dyslexia —
Amnesic Colour-Blindness — Visual Hallucinations — Mind-
Blindness, or Optic Amnesia ...... 3G0

PART II.

OCULAR DISEASES AND SYMPTOMS LIABLE TO ACCOMPANY CERTAIN

DIFFUSE ORGANIC DISEASES OF THE BRAIN.

Disseminated Sclerosis of the Brain and Spinal Cord — Diffuse
Sclerosis of the Brain — General Paralysis of the Insane — Am-
aurotic Family Idiocy — Maculo-cerebral Degeneration — Menin-
gitis — Traumatic Meningitis — Hydrocephalus — Infantile Para-
lysis — Paralysis Agitans — Epilepsy — Chorea . . . ,372

FART III.

OCULAR DISEASES AND SYMPTOMS LIABLE TO ACCOMPANY CERTAIN
DISEASES AND INJURIES OF THE SPINAL CORD.

Tabes Dorsalis — Hereditary Ataxy — Myelitis — Syringomyelia — Myo -
tonia Congenita — Acute Ascending Paralysis — Injuries of the
Spinal Cord 379

PART IV.

NERVOUS AMBLYOPIA, OR NERVOUS ASTHENOPIA.

Nervous Amblyopia in Neurasthenia — Nervous Amblyopia in

Hysteria — Nervous Amblyopia in Traumatic Neurosis . . 383

PART V.

VARIOUS FORMS OF AMBLYOPIA.

Transitory Hemianopsia, or Scintillating Scotoma — Congenital
Amblyopia — Amblyopia during Pregnancy — Reflex Amblyopia
— Night-Blindness — Ura3mic Amblyopia — Pretended Amaurosis
— Erythropsia 390

CONTENTS

CHAPTER XV.

ELEMENTARY OPTICS.

PAGE

Divergence and Parallelism of Rays of Light — Refraction — Index
of Refraction — Plane Glass — Prisms — Spherical Lenses —
Optical Defects of Lenses — Sphero-Cylindrical and Toric
Lenses — Cylindrical Lenses — Numbering and Decentration of
Lenses — Protective Glasses ....... 396

CHAPTER XVI.

ABNORMAL REFRACTION AND ACCOMMODATION.

Ametropia — Myopia — Definition and Causes of M, — Punctum
Remotum in M. — Optical Correction of M. — Diagnosis and
Determination of Degree of M. — Amplitude and Range of
Accommodation in M. — Angle Gamma in M. — Etiology of M. —
Non-Progressive M. — Symptoms of M. — Complications of Pro-
gressive M. — Pernicious M. — Functional Anomalies attendant
upon Progressive M. — Management of ]\I. — The Prescribing of
Spectacles in M. — Operative Cure of M. . . . . .414

Hypermetropia — -Definition, and Optical Causes of H. — Punctum
Remotum in H. — Optical Correction of H. — Determination of
Degree of H. — Amplitude and Range of Accommodation in
H. — Angle Gamma in H. — Varieties of H. in relation to Accom-
modation — Etiology of H. — Symptoms of H. — Accommodative
Asthenopia in H. — Internal Strabismus in H. — The Prescribing

of Spectacles in H 428

Astigmatism — Varieties of As. — Symptoms of Regular As. — Estima-
tion of Degree of, and Correction of As. — The Astigmometer —
Lental As. — Irregular As. ....... 436

Anisometropia . . . . . . . . . .447

Estimation of the Refraction by Aid of the Ophthalmoscope . .447

Retinoscopy . . ... . . . . . . 452

Anomalies of Accommodation — Presbyopia — Paralysis of Accom-
modation — Accommodative Asthenopia — Spasm of Accommo-
dation .......... 460

CHAPTER XVII.

THE ORBITAL MUSCLES AND THEIR DERANGEMENTS.

Normal Action of the Orbital Muscles — Inclination of the Vertical
Meridian in the Several Principal Positions — ]\Iuscles called
into Action in the Several Principal Positions — Subjective and
Objective Localisation — The Field of Fixation . . . 466

CONTENTS

Strabismus — Latent Strabismus, or Heterophoria — Binocular

Vision and Sense of Fusion — Diplopia ..... 472

Paralyses of the Orbital Muscles — General Symptoms — Paralysis
of the External Rectus — Paralysis of the Superior O liquc —
Paralysis of the Internal Rectus, Superior Rectus, Inferior
Oblique, and Levator Palpebrse — Mnemonic Diagrams — Mea-
surement of the Degree of Paralysis — Causes of Paralysis of
Orbital Muscles — Ophthalmoplegic Migraine — Ophthalmoplegia
Externa, or Nuclear Paralysis — Fascicular Paralyses — Myas-
thenia Gravis — Cerebral Paralysis of Orbital Muscles — The
Localising Value of Paralyses of Orbital Muscles in Cerebral
Disease — Congenital Defects of Motion ..... 476

Convergent Concomitant Strabismus — Causes — Single Vision in —
Amblyopia of Squinting Eye — Clinical Varieties of — Measure-
ment of — Mobility of Eye in — Treatment — Optical Treat-
ment — Orthoptic Treatment — Operative Treatment — Tenotomy
— Advancement of External Rectus — Dangers of the Strabismus
Operation — Treatment subsequent to Operation . . , 506

Divergent Concomitant Strabismus . . . . . .525

Latent Deviations (Heterophoria) — Tests for Latent Deviations —
Symptoms — Treatment — Latent Torsion — Insufficiency of
Convergence — Spasm of the Orbital Muscles — The Diplcscope
— Harman's Test 526

Nystagmus — Amblyopic Nystagmus — Coal Miner's Nystagmus—
Vestibular Nystagmus — Nystagmus in Diseases of Nervous
System 536

CHAPTER XVIII.

DISEASES OF THE EYELIDS.

Eczema — (Edema — Marginal Blepharitis (Ophthalmia Tarsi) — Phthei-
riasis Ciliorum — Hordeolum (Stye) — Chalazion (Meibomian Cyst,
Tarsal Tumour) — Milium — MoUuscum — Nnpvus — Xanthelasma
— Chromidrosis — Herpes Zoster Ophthalmicus — Syphilitic
Affections — Vaccine Vesicles — Rodent Ulcer — Solid CEdema,
or Elephantiasis Lymphangioides — Plexiform Neuroma —
Lymphoma — Epithelioma, Sarcoma, Adenoma, and Lupus —
Gangrene — Clonic Cramp of the Orbicularis Muscle — Blepharo-
spasm — Ptosis — Operations for its Cure — Lagophthalmos —
Symblepharon — Blepharophimosis — Canthoplastic Operation —
Distichiasis and Trichiasis — Operations for their Cure —
Entropion, Spastic Entropion, Senile Entropion, Opera-
tions for its Cure — Ectropion — Operations for its Cure — Ihe
Restoration of an Eyelid — Ankyloblepharon — Injuries — Epican-
thus— Congenital Coloboma . . . . . • .541

CONTENTS

CHAPTER XIX.

DISEASES OF THE LACRIMAL APPARATUS.

PA(.R

ivfalposition of the Punctum Lacrimale — Stenosis, and Occlusion
of the Punctum Lacrimale — Obstruction of the CanaHcuhis —
Stricture of the Nasal Duct — Blennorrhcea of the Lacrimal
Sac — Extirpation of the Lacrimal Sac — Acute Dacryocystitis —
Dacryoadenitis — Tumours of the Lacrimal Gland — Cysts of the
Lacrimal Gland — Symmetrical Chronic Swelling of the Lacrimal
and Salivary Glands — Extirpation of the Lacrimal Gland . , Mi)

CHAPTER XX.

DISEASES OF THE ORBIT.

Exophthalmos — Orbital Cellulitis — Tenonitis — Periostitis of the
Orbit — Caries of the Orbit — ^Injuries of the Orbit — Enophthalmos
— Orbital Tumours — Hernia Cerebri — Cysts — Solid Tumours
— Symmetrical Tumours — Pulsating Exophthalmos — Intermit-
tent Exophthalmos — Tumours of the Optic Nerve — Implication
of Neighbouring Cavities — Shrinking of the Conjunctiva-
Temporary Resection of the Outer Wall of the Orbit — Exoph-
thalmic Goitre ......... 590

APPENDIX

Regulations as to Defects of Vision which Discjualify Candidates
for Admission into the Civil, Naval, and Military Government
Services, the Royal Irish Constabulary, and the Mercantile
Marine 625

Index . . . . . . . . . . .63'

TO THE STUDENT.

The student may at first omit the portions printed in small type,
and those marked with an asterisk, including the whole of chapter
xiv. With these exceptions he should carefully read chapters
i., ii., XV., and xvi., immediately on joining the ophthalmic hospital
or department.

xvm

DISEASES OF THE EYE

CHAPTER I.

Preliminary Note on the Clinical Examination of Eye

Patients.

In general medicine and surgery, the importance of systematic
clinical methods is well recognised. System is even more necessary
in the clinical study of diseases of the eye, where the changes from
the normal are often so minute that they may readily escape
observation, and the symptoms depending on derangement of the
functions of the organ are sometimes such, that the patient may
himself be unaware of them.

Before examining the eye, a general observation of the patient
should be made, whereby suggestive hints are often obtained for
diagnosis. For example : the manner m which a patient enters
a room may help to distinguish between an affection of the nervous
apparatus of the eye and cataract, or his gait may suggest an affec-
tion associated with disease of the spinal cord. Again, a strumous
appearance, enlarged glands, eczema, syphilitic eruptions, or the
aspect due to hereditary syphilis afford information not to be
disregarded.

There are many obvious local conditions, which are liable to
escape the attention of a beginner who is, as so many are inclined
to be, too hasty in his desire to make a close inspection of the
eyeball itself ; for example, the presence of slight strabismus,
photophobia, slight ptosis, or the sleepy appearance due to the
heavy thickened lid in granular ophthalmia. We mention these
merely to indicate the advantages which may be gained by quietly
taking a general view of the patient, and of his eyes, at a little
distance, before proceeding to examine the latter more closely.

The examination of the eye may be divided into three parts,
1

DISEASES OF THE EYE. [chap. t.

which are usually taken in the following order : 1. Objective
examination in daylight. 2. Subjective, or functional, examina-
tion. 3. Objective examination in the dark room. All these will
be described in their appropriate places in the following pages, and it
is only necessary here to mention some of their subdivisions. Under
the first will come inspection (and palpation when possible) of
the orbit, eyelids, lacrimal passages, conjunctiva, cornea, anterior
chamber, iris (its colour and structure, and the mobility, shape,
and size of the pupil), anterior layers of the lens in the pupillary
area, and testing the intra-ocular tension. The second will include
tests for acuteness of vision, field of vision, accommodation, binocular
vision, orbital muscles, colour-vision, and light-sense. Finally, in
the dark room the anterior parts of the eye, including the lens,
and sometimes the anterior portion of the vitreous humour, are
first examined by reflected light, with oblique illumination, and then
with a strong -\- lens in the ophthalmoscope. The details of the
fundus are then observed with the ophthalmoscope, and the refrac-
tion is estimated if necessary. One should never omit to compare
the affected eye with its fellow, if only one eye be diseased.

It is not intended that all these methods of examination should
be put into use, or considered even necessary, in every case ; but
they should be borne in mind, if nothing is to escape attention.

OPTICAL STRUCTURE AND FUNCTIONAL EXAMINATION
OF THE EYE.

Optical Structure of the Eye. — The eye is a dark chamber
lined by the uveal pigment, which prevents the rays of light from
entering the eye, except through the transparent media and pupil.
It possesses three refracting or dioptric ^ media, limited by three
convex surfaces. The dioptric media are the aqueous humour,
the substance of the crystalline lens, and the vitreous humour.
The convex surfaces are the anterior surface of the cornea,^ and
the anterior and posterior surfaces of the crystalline lens.

1 The phenomena of refraction are sometimes referred to as Dioptrics,
and those of reflection as Catoptrics.

2 The posterior surface of the cornea may be neglected, since it is
parallel to the anterior surface, and the index of refraction of the cornea
is the same as that of the aqueous humour.

CHAP. I.] OPTICAL STRUGTVUE OF THE EYE. 3

By aid of this apparatus, which is called the Dioptric System of
the eye, distinct inverted images of external objects are formed on
the retina, in the same way as images are formed by a convex lens
(see § 22, chap. xv.).

The refracting surfaces, which are practically spherical, are
centred on the Optic Axis (0 P, Fig. 1), an imaginary line which,
passing through the optical centre (N) of the eye, meets the retina
at a point (P), the posterior principal focus (§ 15, chap, xv.),
slightly to the inner side of the macula lutea (M).

The optic axis of the eye
is similar to the principal
axis of a convex lens (see §
14, chap. XV.). The optical
centre N, which is called the
Nodal Point, is situated just
in front of the posterior
surface of the lens, and rays Fig. 1.— P, Optic axis ; FM, Vis^

passing through it are not "^^^^."^' ^/ F angle y; ^.centre of
T . , T. ,T . ,1 1 . rotation ; iV, nodal point , C, centre of

deviated m their path, being cornea

in fact secondary axes (§ 14,

chap. XV.). F M is the Visual Line, which unites the object
looked at (called the point of fixation) with the macula lutea
(M) and passes through the nodal point.

The Line of Fixation {R V) joins the centre of rotation (7?) of
the eye with the point of fixation. The angle R V formed at the
centre of rotation, by the optic axis and the line of fixation, is
called the angle y.^

The line of fixation and the visual line so nearly coincide that
in practice we regard them as identical ; and hence the angle y
is practically the same as iV F.

The angle k is the angle between the fixation line and a per-
pendicular line through the cornea, opposite the centre of the
pupil. In practice it is the angle k which is measured. It is not

1 Some writers call this angle a (alpha). But the angle a originally-
meant the angle between the visual line and the major axis of the corneal
ellipse, and was founded on the view that the cornea was an ellipsoid —
a view which has been shown to be erroneous by Tscherning and others.
Indeed, the " working area," or optical portion of the cornea, which
includes 13° to 16°, is approximately spherical.

DISEASES OF THE EYE.

.[chap. 1.

equal to the angle y, because the centre of the pupil is a little to
the inner side of the centre of the cornea.

In order to measure the angle k, the eye is placed at the peri-
meter (p. 17) as for an examination of its field of vision, that is
to say, looking at the zero point. A candle flame is then moved
along the arc of the perimeter, until the corneal image of the light
appears to the observer (whose eye is in a line with the candle and
its image) to be in the centre of the pupil. The number on the arc
of the perimeter opposite the candle gives the value of the angle k,
the average size of which is 5°.

Refraction.

By the Refraction of the Eye is meant, in a general sense, the
faculty it has when at rest (i.e., without an effort of accommoda-

FiG. 2.

tion) of altering the direction of rays of light which pass into it,
making parallel rays convergent, and divergent rays less divergent.
But, as usually understood, it means the relation which the position
of the retina bears to the principal focus of the dioptric system.

In Normal Refraction, or Emmetropia (e/xyaerpoi/, the standard ;
o>i//, the eye), as it is termed, the retina lies at the posterior principal
focus (Fig. 2), and therefore parallel rays are brought to a focus
on the layer of rods and cones of the retina, and form on it a dis-
tinct inverted image of the point or object from which they come.
The emmetropic eye, in a state of rest, is thus adapted for seeing
distant objects, and its far point (punctum remotum) is at infinity.
Conversely, if the retina be illuminated, the rays proceeding from
any point on it will emerge from the eye parallel. In the normal
eye the posterior focal length of the dioptric system is 23 mm.

OPTICAL STRUCTURE OF THE EYE.

and the average length of the eyeball including the sclerotic is
24 mm.

Accommodation.

The eye can see near objects distinctly as well as distant objects,
although the rays from any given point (a, Fig. 3) of a near object
reach the eye with a divergence so considerable, that they could
not be brought to a focus on the retina by the unaided refrac-
tion, but would converge towards a point their conjugate focus
a' (§16, chap, xv.), namely behind the retina, and would not form
a distinct image on the latter, but merely a blurred image or circle
of diffusion (at h c). It is obvious, therefore, that an increase of
refracting power in the eye is necessary, in order that near objects

riG.^3.

may be distinctly seen. It is this increase in the refracting power
for the purpose of near vision which is called Accommodation.

The Mechanism of Accommodation is as follows : — The ciliary
muscle (m. Fig. 4) contracts, thus drawing forward the chorioid
and the ciliary processes, and relaxing the zonula of Zinn {z), which
is attached to the latter. The lens {I), which was flattened by the
tension of the zonula, is now free to assume a more spherical shape,
in response to its own elasticity. The posterior surface of the
lens scarcely alters in shape, being fixed in the patellary fossa ;
but the anterior surface becomes more convex, thus increasing its
refracting power. Associated with the act of accommodation is
a contraction of the pupil. The accompanying figure (Fig. 4)
represents the changes which take place in accommodation, the
dotted lines indicating the latter state.

Tscherning has shown that the increased curvature of the
anterior surface of the lens occurs mainly in the centre of that
surface — in other words, that in accommodation the anterior surface
becomes somewhat conical, and not merely more spherical,

6 DISEASES OF THE EYE. [chap. i.

During accommodation, owing to relaxation of the suspensory
ligament, the lens sinks down a little, and becomes tremulous on
movement of tlie eye, and there is no increase in the intra-ocular
tension.

Accommodation is always associated with contraction of the
pupil and convergence of the optic axes.

The Far Point and the Near Point.— It is possible for the eye,

Fig. 4. — c, cornea ; a, anterior chamber ; I, lens ; v, vitreous humour ;
i, iris ; z, zonula of Zinn ; m, ciliary muscle.

by changing the accommodation, to see objects accurately at every
distance from its Far Point — i.e., its most distant point of dis-
tinct vision (Punctum Remotum, — R.), up to a point only a few
centimetres from the eye, called the Near Point (Punctum Proxi-
mum, — P.). We can find the latter by directing the patient to
look at a page printed in small type, and by bringing it slowly
closer and closer to his eye, until a point is reached where he cannot
distinguish the words and letters, which become blurred. A point
very slightly more removed from the eye than this, where he can
read distinctly, is the near point. Between the near point and
the eye vision is indistinct, because no effort of the ciliary muscle
can produce the amount of convexity of the lens required for so
short a distance.

The Amplitude and Range of Accommodation. — This is
the amount of accommodative effort of which the eye is capable
— i.e., the effort it makes in order to adapt itself from its Far Point
(R.) up to its Near Point (P.). The amplitude of accommodation

CHAP. I.] FUNCTIONAL EXAMINATION OF THE EYE. 7

{a), therefore, is equal to the difference between the refracting
power of the eye when its accommodation is exerted to the utmost
(p), and when at rest (/•), as expressed by the formula a = f — r.
It may be represented by that convex lens placed close in front
of the eye, which would take the place of the increased convexity
of the lens, or, in other words, which would give to rays coming
from the nearest point of distinct vision a direction as if they came
from the far point. The number of this lens expresses the ampli-
tude of accommodation in a given eye.

Fig. 5.

For example : if, in an emmetropic eye {E, Fig. 5) the near
point be situated at 20 cm., then a convex lens (L) of 20 cm. focal
length placed close to the eye (between that point and the eye)
would give to rays coming from the near point a direction as though
they came from a distant object {i.e., would make them parallel),
and this normally refracting eye would then be enabled, by aid of
its refraction alone, to bring these rays to a focus on the retina.
Making use of the above equation, we find in this case — since a focal
length of 20 cm. represents a lens of 5 D — that p = 5 and therefore
a = 5 — r, but R being situated at infinity (designated by the sign oo) ,

r = i = i = ; therefore a = 5 — = 5 D.i
K 00

^ It must be observed that R represents the distance of the Far Point
from the eye, while r represents the refractive power which is added to
the eye by accominodation, or by a lens, in order to adapt it for the dis-
tance R. Hence it is evident that r = ^, because the strength, or re-

fractive power, of a lens is inversely as its focal length — e.g., a lens of

the strength of 4 D will have a focal length of ^ that of a lens of 1 D —

1 m. 100 cm. „_ / ooo 1 \ o- 1 1 1 1 1

I.e., — — — = =25 cm. (see § 28, ch. xv.). similarly, p = ^ and a = .'

P representing the distance of the Near Point, and A the focal length of
the lens a which represents the Amplitude of Accomniodation.

DISEASES OF THE EYE.

[CHAP. I.

Fig. 6. — Eye accommodated for
which forms a distinct image on the
retina, R. Parallel rays now unite in
front of the retina at a shorter distance, F.

The amplitude of accommodation {i.e., the number of the lens
which would represent it) is the same in every kind of refraction,
according to the age of the individual, but in emmetropia alone is
a = J) a,s above, because in it alone is r = 0.

It is evident that, as the refractive power of the eye is increased

during accommodation, the
eye is rendered temporarily
myopic as regards parallel
rays (Fig. 6).

Under the head of
" Anomalies of Accommo-
dation," chap, xvi., will be
found Bonders' diagram
representing the amplitude
of accommodation at dif-
ferent ages.
The Range of Accommodation is the distance between the far
point, R, and the near point, P. As will be seen later on, it is not
always the same for a given amplitude.

Connection between Accommodation and Convergence (Relative Accommo-
dation). — By convergence we mean the inward rotation of the eyes
which is necessary in looking at a near object, in order to obtain single
vision with both eyes. With each degree of convergence of tlie visual lines
a certain effort of accommodation is associated. Thus, if the object be
situated 2 metres from the eye, the visual lines converge to that point,
and a certain effort of accommodation (0*5 D) is made. But this connection
between accommodation and convergence is somewhat elastic, for the
accommodative effort may be increased or decreased, while the object is
kept distinctly in view, and the same convergence maintained. That it
may be increased is shown by the experiment of placing a weak concave
glass before the eye, when it will be found that the object is still distinctly
seen ; or if a weak convex glass be held before the eye the object will also
be clearly seen, showing that the accommodative effort may be lessened
without affecting vision or convergence. This amplitude of accommoda-
tion for a given point of convergence of the visual lines, found by the
strongest concave and strongest convex glasses with which the object
can still be distinctly seen, is called the Relative Amplitude of Accommo-
dation. That part of it which is already in use, and is represented by the
convex lens, is termed the negative part ; while the positive part is repre-
sented by the concave lens, and has not been brought into play. For
sustained accommodation at any distance, it is necessary that the positive
part of the relative amplitude of accommodation be considerable in amount.

Moreover, the convergence may be altered, while the same effort of
accommodation is maintained, as is shown by the experiment of placing a

CHAP. I.] FUNCTIONAL EXAMINATION OF THE EYE.

weak prism with its base inwards before one eye. In order that the object
may then be seen singly, it will be necessary for the eye before which the
prism is placed to rotate somewhat outwards ; and it will be found that
the individual can do this, while at the same time he sees the object with
the same distinctness, showing that the same effort -of accommodation
has been maintained, although the angle of convergence of the visual axis
is less than before.

Convergence.

* Range and Amplitude of Convergence. — The nearest point
for which the eye can converge and still
see single is the Near Point of convergence.
The Far Point of Convergence is the point
at which the visual lines meet when the eyes
are at rest ; as the position of rest is one
of slight divergence, this imaginary point
usually lies behind the head, and the devia-
tion from parallelism to this degree of diver-
gence is known as negative convergence.
The Amplitude of Convergence is the sum of
the positive and negative convergence. The
Range of Convergence is the distance be-
tween the far and near points of convergence.

The near point of convergence is found
by bringing an object, such as a fine line,
up to the eyes in the middle line, until it
begins to be seen double. The far point of
convergence, or rather the negative con-
vergence, can be measured by prisms placed
base inwards while the patient looks at a
distant object. In some cases the eyes are
parallel or slightly convergent when at rest, and then convergence
is altogether positive.

Fig. 7.

The Unit of Convergence. The Metre Angle.

If the visual line {E 1, Fig. 7) of an eye {E) be brought to bear on
a point (1, Fig. 7) 1 metre distant from it in the median line {M 1), the
angle of convergence {E 1 M = I E D) which the visual line thus makes
with the median line is called the Metre Angle. It expresses the degree

10 DISEASES OF THE EYE. [chap. i.

of convergence necessary for binocular vision at that distance, and is
employed as the unit for expressing other degrees of convergence. If,
for example, an object be situated ^ a metro (^, Fig. 7) from the eye, the
angle of convergence {E | M) must be practically twice as large as at
1 metre : C. (Convergence) = 2 metre angles. If the object be only | of a
metre distant, 3 metre angles are required : C. =3 metre angles. If the
object be situated 2 metres from the eye, the angle of convergence will
only be one-half as great as that at 1 metre, and here C. = ^ metre angle ;
while if the eye be directed towards a distant object (D) there will be no
angle of convergence, and if the visual lines be divergent the metre angle
will be negative.

Now the emmetropic eye normally requires for each distance of bino-
cular vision as many metre angles of convergence as it requires dioptrics
of accommodation. For a distance of 1 metre an effort of accommodation
of 1 dioptre is required, and also 1 metre angle of convergence ; at \ metre
from the eye 2 D of accommodation is required and 2 metre angles ; at
^ metre from the eye 3 D of accommodation and 3 metre angles, and so
on ; while for distant objects neither convergence nor accommodation
is reqviired. The positive portion of the average normal convergence is
about 10 metre angles and the negative 1 metre angle.

Binocular Vision will be described in chap. xvii.

THE SENSE OF SIGHT.

The Sense of Sight consists of three Visual Perceptions or Sub-
Senses — namely, the Light-Sense, the Colour-Sense, and the Form-
Sense.

The Light- Sense is the power the retina, or the visual centre, has of
perceiving gradations in the intensity of illumination. The light-sense
can be tested by Forster's, or by Izard and Chibret's photometer. On
looking through the latter towards the sky two equally bright discs are
seen. By a simple mechanism one of the discs can be made darker. If
the eye does not perceive the difference in illumination between the two
discs within 5° its light-sense is abnormal, or we may say its L.D. (Light
Difference) is too high. Again, if one disc be made quite dark, and be
then gradually lighted, the patient is required to indicate the smallest
degree of light, or L.M. (Light Minimum), by which he can observe the
disc issuing from the darkness. This should not be more than 1° or 2°.

Another good method is that of Bjerrum, in which the light-sense is
tested by grey letters on a white ground, the letters being constructed
on the same principle as Snellen's Test Types.

A useful and ready clinical method consists in gradually diminishing
the illumination of the test-types and comparing the acuteness of vision
of the patient with that of the surgeon, provided the latter have a normal
light-sense. The L.D. is most affected in diseases of the optic nerve, and
the L.M. in chorioido-retinal affections ; but the measurement of the foymer
is not often required in clinical work.

CHAP, i.l FUNCTIONAL EXAMINATION OF THE EYE, 11

Retinal Adaptation. — It is a common experience, on passing from
daylight into a darkened room, to find that at first nothing is visible,
but that after a time the various objects in the room begin to appear,
until final y almost everything can be seen. This phenomenon is called
" Adaptation " and is due to the fact that the retinal purple, which has
been bleached by light, is only gradually regenerated. In testing the
light-sense, therefore, it is necessary to allow some time for the eye to adapt
itself. Complete adaptation is very slow, but for practical purposes
20 minutes may be deemed sufficient. Adaptation is slower at the macula
lutea than ovitside it, probably because of the absence of rods, which alone
contain the visual purple.

In some diseases, such as retinitis pigmentosa, the power of adaptation
is extremely slow and defective, and gives rise to night blindness. In-
creased power of adaptation, curiously enough, is only met with in total
colour-blindness.

* The Colour-Sense is the power the eye has of distinguishing
light of different wave-lengths. According to the Young-Helm-
holtz theory, the retina possesses at least three sets of colour-per-
ceiving elements, those for Red, Green, and Blue or Violet. These
are termed primary colours because by their combination white
light as well as all other colours can be produced.

According to Hering's theory, the colour-sense and the light-
sense depend upon chemical changes in the retina or in the visual
substances contained in the retina. He suggests the existence
of three different visual substances, the white-black, the red-green,
and the blue-yellow, by the using up or Dissimilation, and restora-
tion or Assimilation of which substances the sensations of light and
colour are produced. These theories are not satisfactory, for they
do not explain cases in which shortening of the spectrum occurs,
and many other facts connected with colour-vision, and they are
not founded on an anatomical basis. Hering's views are com-
pletely disposed of by the discovery that the electrical reactions
in the optic nerve, produced by stimulation of the retina by different
colours, differ only in degree and not in kind.

Edridge-Green's theory, which is the result of many years' study
of the subject, is, that light falling upon the retina, liberates the
visual purple from the rods, and a photograph is formed. The rods
are concerned only with the formation and distribution of the visual
purple, not with the conveyance of light impulses to the brain. The
decomposition of the visual purple by light chemically stimulates
the ends of the cones (very probably through the electricity

12 DISEASES OF THE EYE. [chap. i.

which is produced), and a visual impulse is set up, which is con-
veyed through the optic nerve-fibres to the brain. The character
of the impulse set up differs according to the wave-length of
the light causing it. Therefore in the impulse itself we have
the physiological basis of the sensation of light, and in the
quality of the impulse the physiological basis of the sensation of
colour.

Colour-vision, therefore, consists in the power of distinguishing
between rays of different wave-length, and the greater the degree
of development of the colour-perceiving centre in the brain, the
more acute will be the power of distinguishing differences of
wave-length, consequently the smaller will be the interval in the
spectrum between the rays which are recognised as different, and
therefore the more numerous will be the colours perceived. When
the colour-perceiving centre is badly developed, the points of differ-
ence will be greater, that is to say, the rays perceived as different
will be farther apart in the spectrum, and the number of colours
recognised fewer — in other words, there will be blindness for one or
more colours.

It may also happen that the visual purple is not acted upon by
the rays at the extreme ends of the spectrum, and then the spectrum
will appear shortened.

According to this theory, therefore, the colour-blind are divided
into two distinct classes independent of each other, but which may
be associated. The first class includes those who see the spectrum
shortened at the red or violet ends, or at both ; while in the second
the number of colours visible in the spectrum is smaller than the
normal. A consideration of the way in which the colour-per-
ceiving centre develops, according to Edridge-Green, will help
us to understand the various degrees of colour-blindness. At
first no difference would be recognised, the whole spectrum
would appear of a neutral colour. In the next stage only the
extreme ends of the spectrum would be differentiated, namely,
the red and violet, with a more or less wide neutral band of grey
between them ; the grey band would gradually diminish until
the two colours met ; following on this stage a third colour would
appear at the next point of greatest difference, namely, at the
centre of the spectrum in the green, and so, in order of succession,
yellow, blue, and orange would be added. Thus, if the normal-

CHAP. I.J FUNCTIONAL EXAMINATION OF THE EYE. 13

sighted be designated as liexacliromic (seeing six colours) ,i the colour-
blind may be divided into the pentachromic (seeing five colours
— red, yellow, green, blue, violet), the tetrachromic (seeing four —
red, yellow, green, violet), the trichromic (seeing three — red,
green, violet), the dichromic (seeing two — red and violet), and
finally, the monochromic, or totally colour-blind.

It must be remembered, however, that all grades of transition
exist between total colour-blindness and a normal colour-sense,
so that even in one class, say the dichromic, it is difficult to find
two colour-blind persons who will behave exactly alike with all
tests.

Colour Tests. — Testing the colour-sense is by no means a simple
matter. It requires a good deal of experience, as well as a know-
ledge of colour-blindness and of the eye itself, to apply the tests in
a really satisfactory way. It is advisable therefore that they should
not be entrusted to laymen, or even scientists, but should be carried
out by ophthalmologists.

The spectrum affords the most accurate of all tests, but a special
spectroscope is required, and, owing to the expense and expert
knowledge necessary, as well as to the fact that a certain degree
of intelligence on the part of the patient is required, it is hardly
suitable for clinical use.

It is now almost universally admitted that Holmgren's coloured
wool test is inadequate as an efficient test.

Edridge-Green uses two tests, a classification test and a lantern
test. The Classification Test consists of a number of coloured beads
in which every variety of confusion colour of the colour blind is
well represented, and a box with four compartments into which
the beads can be dropped. The aperture to each of the compart-
ments is such that the observer cannot see the bead after it has
been dropped into the box. The four compartments of the box are
labelled Red, Yellow, Green and Blue. The examinee is told to,
pick out from the beads in front of him, which are placed on the
white porcelain lining of the box, all those that are red, keeping
as nearly as possible to the exact hue, but selecting those that are
lighter or darker of the same colour, and to drop them one by one
into the compartment labelled Red. He then goes through the

1 In very rare cases a seventh colour, called ind'go, is seen in the
spectrum.

U DISEASES OF THE EYE. [chap. i.

same process with the three other colours ; he is not allowed to
compare the colours directly, but must select them entirely according
to the name which he gives to the colour. It will be found that
whilst the normal-sighted are able to select the correct colours
with the greatest ease, the colour-blind will make their characteristic
mistakes. This test, like the lantern, will detect cases of colour
scotoma as well as those of ordinary colour-blindness.

The Lantern Test, which is very efficient and practical, consists
of a lantern with coloured glasses revolving behind a circular
opening which can be altered in diameter. The colours can be shown
separately or combined, and can be modified by neutral or ribbed
glass, so as to represent signals as they are affected by distance?
fog, or rain. It forms an ideal test for railway servants and sailors.
The examinee is asked to name the colour of the light shown. The
use of colour names is absolutely necessary, or normal-sighted
persons will be rejected, through paying attention to shade rather
than to colour. It does not matter what name is applied to a colour ;
but ground for rejection is afforded when the examinee calls two of
the main colours of the normal-sighted, as, for instance, red and
green, by the same name.

Since all grades of colour-blindness exist, the practical question
therefore is to draw the line at which rejection should take
place.

The following should be rejected as being dangerously colour-
blind : 1. Those who see only three colours (trichromics), or less
than three. 2. Those who have a shortened red end in their spec-
trum, even though they may be hexachromics. 3. Those affected
with central scotoma for red or green.

Stilling's test, in which spots of a given colour are printed on
a background of a confusion colour, finds favour with some.

Colour-blindness is either congenital or acquired. Congenital
colour-blindness occurs in 3 '5 per cent, of men and less than 1 per
cent, of women. It is hereditary, but is transmitted by females
with normal colour sense.

Acquired colour-blindness* is found in toxic amblyopia, in atrophy
of the optic nerve, and in some other conditions.

The Form-Sense (Acuteness of Vision). — By Acuteness of Vision
(V) is meant the power which the eye, or rather the macula lutea,
has of distinguishing form, any anomaly of its refraction, if such

CHAP. I.] FUNCTIONAL EXAMINATION OF THE EYE. 15

exist, having been first corrected. In clinical ophthalmology
the testing of this function is an important and ever-recurring
duty.

When applied to by a patient on account of imperfect sight
it is our first duty, as a rule, to ascertain accurately the condition
of refraction and accommodation of his eyes. Should these be
abnormal, and it be found that by aid of the correcting glasses
perfect vision is obtained, it may, in general, be concluded that the
eye is organically sound, and that the patient's complaints are due
to the defect in accommodation or refraction. If glasses do not

Fig. 8.

restore perfect vision, we must then, by the ophthalmoscope and
other methods, decide the nature of the defect.

Now, in order to measure the acuteness of vision we must have
a normal standard for comparison — i.e., we must find what is the
size of the smallest retinal image whose form can be distinguished.
We cannot, of course, measure this image on the retina directly ;
but, as its size is proportional to the visual angle — the angle which
the object subtends at the eye — it is sufficient to determine the
smallest visual angle under which the form of an object can be
distinguished. It has been found, experimentally, that the average
size of this angle is 5 minutes (Fig. 8).^

In order practically to ascertain the degree of acuteness of vision
we place our patient with his back to the light, while facing him
at a distance of 6 metres, and in good light, are placed Snellen's
Test-Types for distance. These types are so designed that, at the
distance at which they should be seen, they each subtend an angle

^ The minimum separabile or smallest angle under which two points
can be distinguished is 1 minute, and corresponds approximately with the
distance between three retinal cones, the central one not being stimulated.

16 DISEASES OF THE EYE. [cHAt. I.

of 5' at the eye. The largest type should be seen at 60 metres
(Fig. 8) by the normal eye, and the types range from this down
to a size visible not farther off than 6 metres. If V=Acuteness
of Vision, d = the distance from the eye to be tested to the test-
types, and D = the distance at which the type should be distin-
guishable, then V = ^. For example : if d = 6 metres (a distance
which most rooms can command), and if the eye see type D = 6,
then V = f = 1, or normal V. ; but if at 6 metres the eye see
only D = 60, which should be seen at 60 metres, then V = -^^,
in short V = 6 divided by the number of the type read. A distance
of 6 metres is selected because the test-types are also used to test
the refraction, and at that distance the rays proceeding from the
type may be considered to be parallel.

In practice these fractions must not be taken in a strict mathe-
matical sense. For example, /^ does not mean that a patient with
that degree of V has his visual capacities lessened by one-half.

A series of types resembling the letter E, in various positions,
is also used for testing illiterates. Or, better still, an incomplete
circle like the letter C in different positions can be used, the patient
being required to tell where the break in the circle is placed. This
has lately been recommended as a universal test. The types of
Jaeger for near vision are sometimes used for testing the acuteness
of V.

Should the patient's sight be so defective that he is unable to
read any of the letters, it may be tested by finding at what distance
he can count the surgeon's fingers ; and if he cannot even do that,
then his power of perception of light (his P.L.) should be tested.
This is done by means of a lamp in a dark room, the eye being
alternately covered and uncovered, and the patient being required
to say when it is " light " and when " dark." If the flame be
gradually lowered the smallest degree of illumination perceptible
will be ascertained.

The eyes must be examined separately, that one not under
examination being excluded from vision by being shaded with the
patient's own hand or other suitable screen ; but it must not be
at all pressed on, as ^ny pressure would dim its vision when its
turn for examination may come. When a trial frame is put on,
the patient should not be allowed to turn his face to one side, or else
he may be with the eye which is covered.

CHAP. I.] FUNCTIONAL EXAMINATION OF THE EYE. 17

With the advance of age the acuteness of vision undergoes
a slight but steady reduction, owing to certain senile changes in
the eye.

THE FIELD OF VISION.

By the Field of Vision (F.V.) is meant the space within which
objects can be seen by one eye, the other being closed, the gaze of
the former being fixed on some one object or point. Thus, if stand-
ing on a hill, we fix the gaze of one eye on some object on the plain
below, the field of vision includes not only that object, but many
others also for miles around it.

The fixation object is seen by central or direct vision, its image
being formed on the macula lutea ; the other objects in the field
of vision correspond with as many different points in the more
peripheral parts of the retina, and are seen by eccentric, or indirect,
vision. Eccentric vision is of great importance for guiding oneself
and for the avoidance of obstacles. This may be realised by the ex-
periment of looking through a long small-bore cylinder {e.g., a roll
of music) with one eye, thus cutting off its eccentric field, while
the other eye is closed.

The Examination of the Field of Vision (Perimetry) is carried
out for clinical purposes by means of an instrument called the peri
meter. This is a semicircular arc of metal capable of revolving
upon its middle point, so as to describe a hemisphere in space. The
arc is divided into degrees from 0° at its middle point, to 90° at
either extremity. At the centre of the hemisphere is situated the
eye under examination, while the fixation point is placed exactly
opposite, in the middle of the semicircle, at 0°. The test object,
a small bit of white paper 5 or 10 mm. square, is slowly moved
along the inner surface of the arc from the periphery towards the
centre, until it comes into view, and the observation is repeated in
various meridians. The horizontal, vertical, and two intermediate
meridians, at least, should be examined by placing the arc of the
perimeter in the corresponding planes. The patient's eye must
be carefully watched, as any movement of it away from the fixation
point would vitiate the results.

The boundary of the field is noted on a diagram or chart (Fig. 9) ,
which represents the projection of a sphere on a plane surface.
The radii represent different meridians, and are indicated by a

DISEASES OF THE EYE.

[chap. i.

dial with pointer on the back of the perimeter, while the concentric
circles correspond with the degrees marked on the arc. A pencil
mark is placed on the chart at the spot corresponding with that on
the perimeter at which the test object comes into view ; and, when
the different meridians have been examined, these marks are united
by a continuous line, which then represents the outer boundary
of the F.V. In some cases (hemianopsia, etc.) it is better to take

Right Eye

80
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100

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160

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Fig. 9.

the field by the circular method, i.e., by placing the test object
successively on the different degrees of the arc, and each time
rotating the arc through a complete circle, the points or meridians
at which the object appears and disappears from view being noted.
The normal F.V. is not circular, but extends outwards about
95°, upwards about 53°, inwards about 47°, and downwards about
65°, as represented by the strong curve in Fig. 9. The limitation
upwards and inwards is partly due to the projection of the supra-
orbital margin and the bridge of the nose, but also to the fact that
the outer and lower parts of the retina are less practised in seeing
than are the upper and inner parts, and their functions consequently

CHAP, i.j FUNCTIONAL EXAMINATION OF THE EYE. iw

less developed. The acuteness of vision diminishes progressively
towards the periphery of the field, two points of a certain size close
together being distinguishable from each other only a short distance
from the fixation point, while the farther towards the periphery
the larger must be the test objects.

Fig. 10 serves to illustrate the projection of the field of vision
of the right eye on the semicircle of the perimeter to its extreme
temporal (95°) and its extreme nasal (47°) boundaries, as well as
the portion of the retina {a to b) which corresponds with this extent
of field ; and it shows that the sensitive portion of the retina, or

Fig. 10.

rather perhaps the portion of the retina which is most used, ex-
tends farther forward on the nasal than on the temporal side. The
diagram also explains the remarkable fact that the field extends in
the temporal direction more than 90°.

The Blind Spot of Mariotte is a small blind island or scotoma
in the F.V. It takes the shape of an oval with the long axis vertical,
whose centre is situated about 15° to the outer side of the point of
fixation and just below the horizontal meridian. It is shown
as a dark spot in Fig. 9. It is due to the optic papilla (optic disc),
for at that place the outer layers of the retina are wanting, and
hence it possesses no power of perception.

DISEASES OF THJS EYE.

[CHAt*. 1.

For the detection of small defects such as enlargement of the
blind spot and central scotomata in the early stage, it is necessary
to employ Bjerrum's Method, in which the observations are made
with a black (velvet) screen at a distance of 1 or 2 metres, using
a very small test object, of 1 or 2 mm., or Priestley Smith's
scotometer may be used. The field of vision when taken in this
way is much smaller, and is approximately circular, measuring
about 30°. An exact record, therefore, of a perimetric examination
should give the size of the test object and its distance from the
patient's eye ; these particulars are then entered as a fraction having
the former as numerator and the latter as denominator.

The presence of a
gross alteration in the
field may be roughly
ascertained if the ob-
server face the patient,
who has his back to
the light, and use his
own hand as a test ob-
ject. The eye of the
observer which is oppo-
site the patient's eye
serves as a control, as
its field can be tested
at the same time as
that of the patient's
eye.
In the Binocular Field of Vision, since the two visual lines meet
at the fixation point, the central portion is common to both eyes
(Fig. 11).

* Pathological Defects in the Field of Vision.— As these are
often of great diagnostic importance, it will be advisable to give a
summary of the various types which are met with.

Pathological alterations of the fields of vision may be divided
into (1) Contractions of the field which begin at the periphery,
(2) Insular defects, and (3) Loss of a half of the field, usually affecting
both eyes and extending to the middle line.

Contractions of the visual field may be {a) concentric as in
atrophy of the optic nerve (Fig. 12), retinitis pigmentosa, and hys-

FiG. 11. — Binocular Field of Vision. The
white area is common to both eyes, P being
the fixation point. The shaded portion on the
right belongs to the right eye alone, while that
on the left belongs to the left eye alone.

Left Eye

temp

Fig. 12. — Extreme concentric^con- Fig. 13. — F.V. from case of Glaucoma,

traction of F.V. in atrophy of the
optic nerve.

160 '80

Fig. 14. — Sector defect in F.V. from branch embolism of the central
artery of the retina.

left Eye

160 '80

Fig. 1 5.— Sector-like defects in F.V. from case of disseminated sclerosis.

DISEASES OF THE EYE.

[chap.

terical amblyopia or (6) the defect may begin at a certain part
of the periphery, as in glaucoma (Fig. 13), where the nasal side is
the first to become affected, or as in detachment of the retina, when
the portion of the field which is lost will depend on the position
of the detachment. If this be below, as is most commonly the case,
then the defect in the field will of course be above, (c) Sometimes
the defect is irregular, or sector-like ; examples of this variety of
field occur in embolism of a branch of the central artery of the
retina (Fig. 14), and in some cases of atrophy of the optic nerve
associated with tabes or multiple sclerosis (Fig. 15).

An insular defect, which is termed a scotoma, may be central,

ISO 180

Fig. l(i. — Central scotoma for red and green in toxic amblyopia.

that is, involving the fixation point, or paracentral, in close proximity
to it, or again it may be situated in any part of the remaining field.
A central scotoma is an important symptom in toxic amblyopia
(e.g. from Tobacco and Alcohol poisoning. Fig. 16) and in retrobulbar
neuritis due to other causes, such as disease of the posterior nasal
accessory sinuses. It sometimes makes its appearance in the very
earliest stage of multiple sclerosis. In the cases just mentioned both
eyes are affected, whereas the scotoma following on disease of the
macula lutea is often unilateral. Non-central scotomata may arise
from retinal haemorrhages (Fig. 17), intra-ocular tumours (Fig. 18),
and disseminated chorioiditis.

A peculiar form of scotoma is the annular or ring-scotoma which

Lef) Eye

lUyhtEyc

Fig. 17. — Scotoma in the F.V. Fig. 18. — Large scotoma caused

caused by a large retinal haemorrhage. by an intra-ocular sarcoma.

Fig. 19. — Irregular annular scotoma due to specific chorioido-retinitis.

80 80]

7 r~7ioo 100

Fig. 20. — Bitemporal hemianopsia in a case of pituitary disease which proved fatal.

24 DISEASES OF THE EYE. [chap. i.

surrounds the fixation point, without involving it. It is met
with in retinitis pigmentosa and in syphilitic chorioido-retinitis
(Fig. 19). ^

3. Hemianopsia will be dealt with more particularly in chap. xiv.
When the right or left halves of both fields are lost, the condition
is termed Homonymous Hemianopsia. If both temporal halves
are blind then we have a Bitemporal Hemianopsia. The commonest
cause of the former is a haemorrhage in the mesial surface of the
occipital lobe, and of the latter tumour of the pituitary body (Fig.
20). In some instances a quarter of the field only is lost in each eye ;
but this is merely an incomplete form of hemianopsia.

A defect in the field is Positive if it be visible to the patient as a
dark area. Negative if it be invisible. If the blindness be complete,
the defect is said to be Absolute ; but if the acuteness of vision
be merely diminished, it is said to be Eelative. A relative defect
may exist for colours only (Fig. 16), most commonly for red
and green. In all eyes the blind spot is a negative and absolute
scotoma in the field of vision. When the vision is too defective
to permit of the field of vision being tested in the ordinary way,
the patient may be asked to indicate the position of a light placed
in different parts of the field ; this is called testing the Projection of
Light.

The Perception of Colours in the Periphery of the Field can be
examined with the perimeter, by means of bits of coloured paper
not more than 5 mm. square. It has been in this way ascertained
that the boundaries of the power of eccentric perception for the
different colours do not seem to correspond with the boundary for
white light, nor do the boundaries of the different colours seem to
incide. Examining from the periphery towards the centre by
ordinary daylight, blue is the colour which can be distinguished as
such most eccentrically, its field extending nearly as far as the general
F.V. ; then come yellow, orange, red, and, with the most limited
field, green. Blue, red, and green being the most important, their
fields are noted in Fig. 9. Although the respective colours are
distinguishable within the limits indicated, they are by no means
so brilliant in hue as when seen by direct vision. It has, however,
been demonstrated that every colour is recognisable up to the outer
limit of the F.V., if the coloured object be of sufficient surface and
be sufficiently illuminated; so that there is, in fact, no absolute

CHAP. I.] FUNCTIONAL EXAMINATION OF THE EYE. 25

colour-blindness in the peripheral parts of the retina, but merely
a diminished sensitiveness to coloured light.

Pathological Changes in the Colour Fields need only be referred
to briefly. The most important are : (1) The central scotoma for
red and green which occur in toxic amblyopia (Fig. 16). (2) The
concentric contraction of the colour fields in atrophy of the optic
nerves, which often precedes the failure for white, and in the later
stages progresses more rapidly, so that the field for colours is rela-
tively more reduced in size than that for white. (3) A hemianopsia
may also exist for colours only (see chap. xiii. part 1), to be
followed later by loss of the half fields for white. (4) Finally
the normal order of the boundaries of the fields for the different
colours may be, to a certain extent, reversed, or instead of being
concentric they may overlap. These conditions have been observed
in cerebral tumours and in hysteria.

That colour defects can exist alone, does not require the assump-
tion of the existence of a separate cortical centre for colour vision ;
indeed, facts seem rather to support the view that lesions of the
visual nerve fibres interfere more easily with the transmission of those
impulses which produce colour vision, than with those which cause
the sensation of white.

The Perception of Form in the Perifhery of the Field is very
defective, and its examination is not of much practical importance ;
but this portion of the field is very sensitive to the movement of
objects.

Enlargement of the Blind Spot occurs in cases of opaque nerve fibres,
posterior staphyloma, and optic neuritis, but of late it has been pointed
out that an increase in size of the blind spot for white or colours is one of
the earliest signs of involvement of the optic nerve in disease of the posterior
nasal accessory sinuses and appears before the central scotoma. Accord-
ing to Van der Hoeve the blind spot measures on an average about 7°
vertically, 5° horizontally, and is surrounded by a colour-blind area of less
than 1°.

CHAPTER II.

THE OPHTHALMOSCOPE.

Before proceeding to describe the ophthalmoscope, a brief statement
of the properties of plane and concave reflecting surfaces (or mirrors) will
be of use.

Laws of Reflection. — When a ray of hght, O S (Fig, 21), meets a polished
surface or mirror, M M, at a given point, S, the angle of incidence, i, formed
with the perpendicular to the surface, P, is equal to the angle of reflection,

r, and the incident and reflected rays O S,
S R, lie in one plane.

Images formed by a Plane Mirror. — To
an observer placed at R the point O
would seem to be at I, where the prolonga-
tion of R S intersects the line I O per-
pendicular to the mirror, and O M is
equal to M I. Similarly the image of the
point B is found on the perpendicular
B E, E D being equal to D B. The
image I E therefore, formed by a plane
mirror, is virtual, erect, and situated
behind the mirror &X the same distance
from it as the object O B.

Images formed by a Concave Mirror. —
In Fig. 22, c is the centre of curva-
ture of the mirror M M. The rays a, b,
parallel to the axis S /, meet the surface of the mirror at M and M' and
are reflected to F the principal focus. The angle of incidence a M c being
equal to the angle of reflection F M c, the radius c M being perpendicular
to the surface of the mirror at M, F lies midway between S and c ; that is to
say, the focal length of a concave mirror is equal to half the radius. Rays
from a point /, beyond c, are made to converge at /', between F and c,
and the farther away / is the nearer will /' be to F ; / and /' are con-
jugate foci. The conjugate focus of a point nearer the mirror than F
would be virtual, because the rays then diverge after reflection.

In ophthalmoscopic work the source of light is usually farther away
than the centre of curvature of the mirror, and Fig. 23 shows how, in this
case, a real inverted and diminished image of the light is formed. The
image of the point O is found at I, the point of intersection of the ray

Fig. 21. — Reflection by a
plane mirror.

THE OPHTHALMOISCOPE.

O I, which passes through the centre of curvature C, without deviation,
and the ray O S parallel to the axis, which passes through the principal
focus F, after reflection ; the image of the point B is found in a similar
manner. As O B ap-
proaches C, I M also
approaches it, and in-
creases in size until at
C object and image
are of equal size and
coincide. When the
object lies between F
and the mirror, a vir-
tual, erect, magnified
image is seen. A con-
cave mirror therefore
resembles a convex lens in its action (chap, xv., § 5.)

Fig. 22. — Reflection by a concave mirror.

To distinguish a Plane from a Concave Mirror the student should
stand with his back to the source of light and, with the ophthal-
moscope held in front of him and a little to one side, should throw
the light reflected from it into his own eye ; he will then see an
erect image, if the mirror be plane, or an inverted image, if the
mirror be concave. A simpler method consists in facing the source
of light, and throwing the reflected light on a screen, say the palm
of the hand, and moving the mirror towards or away from it ; then,
if the mirror be plane, a round image with a dark central spot
will be formed at all distances ; but. if the mirror be concave, at

a certain distance
an inverted image
of the source of
light will be formed.
The Ophthalmo-
scope .—Although
the dioptric media
of an eye may be
perfectly clear and
normal, yet no de-
tail of its fundus
can be discerned by
the unaided eye of an observer who looks through the pupil, the
latter being for him merely a dark opening. The reason of this
is, that light can only enter the eye through the pupil and
the refractive media. In albinos the pupil appears red, because

Fig. 23. — Image formed by a concave mirror
when the object is beyond the centre of cur-
vature.

DISEASES OF THE EYE.

[chap. II.

the absence of the uveal pigment allows the light to penetrate the
sclerotic and illumine all the interior of the eye in a diffuse manner.
To explain : — Suppose the inside of a small box {vide Fig. 24) to be
blackened, and on its floor some printed letters fastened, and a hole
cut in the lid, which is then replaced — it will be found that, by aid

Fig. 24.

of a lighted candle and with a little experimentation, the letters
may be read through the aperture. The rays passing from the
light (L) into the box through the aperture illuminate the opposite
surface, and from this surface the rays a. h, and others pass out
again through the opening, and some of them fall into the observer's
eye at E.

But if, in order to make this box represent an eye, we place a
convex lens, 71, of the proper strength, immediately within the
aperture, all the rays passing into the box (Fig. 25) from L are
brought to a focus on its opposite side at m by the convex lens n,

Fig. 25.

and, according to the law of conjugate foci (§ 17, chap. xv.). all the
rays passing out from the box meet again at the source of light (L),
and hence none of them can be received by the eye (a) of the observer ;
nor can this eye be placed in any position where it could receive
any of these rays, for if it be placed anywhere between the aperture
and L, it would cut off the light passing from L into the box.

CHAP. II.] THE OPHTHALMOSCOPE. '20

If the back of the box were further forward, the light would
not be focussed on it, and the emergent rays would form parallel
or conical divergent beams passing back to and surrounding L.
In the latter case, if an observer held his eye close beside the light,
some of the divergent rays would enter it, and the letters would be
visible. This explains the red pupil often seen in hypermetropia
and aphakia.

Hehnholtz's Ophthalmosco'pe. — If the eye of the observer could
itself be made the source of light, the difficulty would be solved ;
and, practically, this is what Helmholtz accomplished with his
ophthalmoscope in the year 1851. The instrument he invented

Fig. 26.

was composed of a number of small plates of glass {0, Fig. 26), from
which light from L was reflected into the eye (E), and thus the
fundus of the latter was illuminated. From m rays pass back again
by the same path to the ophthalmoscope, some being reflected
back to L ; but some, passing through the ophthalmoscope, and
falling into the observer's eye placed close behind the instrument
at a, form in it an image of m.

Modern Ophthalmoscope. — For the original ophthalmoscope of
Helmholtz a concave mirror of 20 cm. focal length with a central
opening has been substituted. This mirror (0, Fig. 27) throws
convergent rays into the eye {E) ; and these, being made more con-
vergent by the refracting media, cross in the vitreous humour, and
light up part {a b) of the fundus. From every point of this illumin-
ated surface rays are reflected back again out of the eye. If the
latter be emmetropic, the rays from any one point become parallel
on leaving it ; and some of these parallel rays, passing through the
aperture of the ophthalmoscope, fall into the observer's eye, and,
if it be emmetropic, are brought to a focus on its retina ; the rays

30 DISEASES OF THE EYE. [chai'. it.

from m at m\ those from a: at a;', and those from y at y' — and thus
an image of the part x m y is formed on the observer's retina.

Fig. 27.

The foregoing method of examining with the ophthalmoscope is
called the Direct Method, or the Examination of the Upright Image.
The light should be placed on the same side as the eye to be examined,
it should be on a level with the eye, and sufficiently behind the
patient to leave the eye in the shade. The observer uses his left
eye for the patient's left eye, and his right for the patient's right
eye, and by a slight inclination of his head he can get very close to
the patient's eye without coming into contact with his face. By
this method the various parts of the fundus are seen in their natural
positions, but much enlarged. The magnification is about 15
diameters in Em., more in M. and less in H. ; and it is consequently
very valuable for examining minute details. The area visible at
one moment is, however, small, not much larger than the optic disc.

It is necessary that the observer should approach his eye as
close as he can to the eye under examination, in order to receive as
much of the light coming out of it as possible, and also to obtain
the largest possible field. The extent of the area visible at one
moment depends also on the refraction, being greatest in H., and
least in M.

Moreover, the accommodation both of the observer's and of
the patient's eye must be at rest, as otherwise the rays coming
from the latter cannot form an image on the retina of the former,
at least if both be emmetropic. If the patient exert his accommoda-
tion, the rays will, on leaving his eye, become convergent instead
of parallel, and, falling into the observer's eye, will be brought to a
focus in front of his retina. The same will happen if the observer

OHAP. ii.l THE OPHTHALMOSCOPE.

exert his accommodation, and still more so if both patient and
observer accommodate. The patient's accommodation can be
relaxed by making him gaze at the black wall behind the observer's
head, or his accommodation may be paralysed with atropine. But
atropine should never be used in adults unless absolutely necessary,
owing to the inconvenience it causes the patient.

Voluntary relaxation of the accommodation on the part of the
observer is often a matter of much difficulty to beginners. With
parallel optic axes our accommodation is relaxed ; therefore, when
we want to relax our accommodation, we produce parallelism of
our optic axes. . This sounds easy enough ; yet, when the beginner
approaches his eye close up to that of his patient, the knowledge
that he is so close to the object he wishes to see renders the accom-
plishment of this parallelism and relaxation of accommodation
very difficult to many. It can only be attained by practice, but it
is assisted by the fact that the eye which is not in use gazes at the
black wall behind the patient's head. A beginner will find a low
concave lens behind the mirror of great assistance.

Fig. 28.

The Indirect Method, or the Examination of the Inverted Image,

is employed in order to obtain a more general view of the fundus
than the direct method admits of.

In addition to the ophthalmoscope, a convex glass — the object
lens — {I, Fig. 28) of about 14 D is here used. The latter is held at
about its focal length from the eye {E) under examination, while
the observer throws the light from the mirror through it into the
eye. In passing through I the rays are made convergent, and this
convergence is increased by the refracting media, so that the rays
cross in the vitreous humour, and light up a portion of the fundus

32 DISEASES OF THE EYE. [chap. n.

oculi. From any points {a and h) of this illuminated place pencils
of rays pass out again from the eye, and, becoming parallel, pass
through I and are united by it at a' h' ; and thus a real inverted
image, magnified about 4 or 5 diameters, is formed of the part a b,
which image may be seen by the observer whose eye is placed behind
0. In Em. the image will be formed at the principal focus of the
object lens because the emerging rays are parallel, in H. it will be
found farther away from the lens, and in M. nearer to the lens than
in Em. The stronger the object lens (/) the more convergent will
the rays from the examined eye be made ; and consequently the
closer must a' h' be to each other, and the smaller and brighter must
be the image formed. The weaker the object lens the larger and
less brilliant is the image, and the less annoying to the observer
are the reflexes from its surfaces.

If the lens be held at its focal length from the cornea, and then
withdrawn until its principal focus is farther from the eye than
the anterior focus of the latter, the image will remain unaltered in
size in Em., will increase in size in M., and diminish in H.

In examining by the indirect method, the observer first places
the upper edge of the ophthalmoscope to his right supra-orbital
margin, and, taking care that he is looking through the central
opening of the mirror, he reflects the light of the lamp into the
patient's eye at a distance of about 50 cm. A red glare from the
fundus, known as the " red reflex," will then be seen in the pupil.
Keeping the pupil illuminated, the convex lens of 14 D, held between
the forefinger and thumb of the observer's left hand, is brought
up in front of the patient's eye, and kept there in the perpendicular
position, the observer steadying his hand with the tip of the little
finger on the patient's forehead. The object lens is now removed
just far enough from the patient's eye to cause the margin of the
pupil to disappear out of the observer's field of vision. The observer
then ceases to look into the eye, and fixes his gaze on the object
lens, when the inverted image of the fundus should at once be-
come visible, if the observer accommodates for the proper distance
— and will seem to be situated in the object lens, although it really
is in the air somewhat this side of the lens. Beginners often fail to
see the fundus clearly, because they do not accommodate sufficiently,
and hence a low -{- lens placed behind the sight hole of the mirror
helps to bring the image into focus.

CHAP. II.]

THE OPHTHALMOSCOPE.

If, as is usually the case, the ophthalmoscope be held in the
right hand, it is better to place the light on the patient's left,
whichever eye be examined, as the observer's left arm will not then
interfere with the light when the lens is held up before the patient's
eye.

The diagram (Fig. 29) serves to illustrate the eifect of inversion
of the image. The left eye is seen in the upright image at a, while
the same eye is seen in the inverted image at h. In the diagram
the two images are of the same size for the sake of convenience ;
although, of course, in reality the upright image is much larger

Fig. 29.

than the inverted image. Moreover, it should not be supposed
that nearly the whole fundus oculi, as here represented, can be
taken in at one view with the ophthalmoscope. The portion visible
with the ophthalmoscope at one moment, even in the inverted
image, is small ; so that it is necessary to examine the different
regions in detail, in order to become acquainted with the condition
of the whole of the fundus.

The reflex from the surface of the cornea gives a good deal of
annoyance to every beginner. It cannot be done away with, but is
considerably diminished by holding the object lens farther from the
cornea than the focal length of the lens ; and, as it moves in the
opposite direction to a motion of the object lens, it is possible to
see past it.

Reflexless ophthalmoscopes which get rid of the corneal reflex by
making use of different portions of the patient's pupil for the entering
and emergent rays have been designed by Thorner, and by Gullstrand.
In Gullstrand's method of ophthalmoscopy a Nernst lamp with a fine
vertical slit acts as the source of light. It ensures a brilliant illumination
and shows up fine details with great definition.

34 DISEASES OF THE EYE. [chap. n.

The reflections from the convex object-lens are also extremely
annoying, but may be removed to a great extent from the line of
sight by a slight rotation of the lens on its axis. If a very high
object-lens (say + 20 D) be used, the reflections from it are more
disturbing than from a lower number (say + 14 D).

To examine the Opic Nerve (or Optic Disc) the observer sits in
front of the patient, and directs him to turn his eye somewhat
to the nasal side, and slightly upwards ; because the optic nerves,
diverging from the chiasma, enter the back of the eye a little to the
inner side of the posterior pole, and the papilla, or disc, comes to
be situated about 15° to the inner side of the posterior pole of the
eye, and about 3° above it. For instance, if the left eye be examined
the patient is to direct his gaze, (without turning his head,) to his
right and a little upwards, say towards the observer's left ear. It
is well always to seek out the optic papilla in the first instance,
not only because it is such an important part of the fundus oculi,
but also because, examining from it towards the periphery, we are
the better able to determine the locality of any pathological alter-
ation.

Should the patient not direct his gaze in such a way as to enable
the observer to see the optic disc or other desired region, it may be
brought into view either by a motion of the observer's head in the
opposite direction, or by a motion of the object-lens in the same
direction, or by a combination of these measures. When the disc
is opposite the observer's eye, the pupillary reflex is seen to become
paler or even white, and the corneal image of the light will occupy
the junction of the middle and outer thirds of the horizontal dia-
meter of the cornea.

The Macula Lutea should then be examined. It may be seen
by directing the patient to look straight at the hole of the ophthal-
moscopic mirror, for it will then correspond with the macula lutea
of the observer's eye. It is more readily seen in the inverted than
in the upright image ; but its examination is often very difficult,
owing to contraction of the pupil produced by the strong light falling
on so sensitive a portion of the retina, and by the reflections from
the surfaces of the cornea and crystalline lens, which fill the area
of this contracted pupil. It is therefore a better plan to direct the
patient to look somewhat to the side of the eye under examination
— e.g., to the right side of the observer's forehead, if the left eye

THE OPHTHALMOSCOPE.

be under examination, and then by motions of the object-lens to
bring the macula lutea into view.

After this the Periphery of the Fundus in every direction is
to be examined by making the patient look upwards, downwards,
to the right, to the left, etc.

The indirect method possesses the following advantages : —
It gives a large field in which it is possible rapidly to locate the
position of a lesion, it can be used no .matter what the error of
refraction may be, and it is not necessary to approach close to
the patient's face.

Detection of Opacities in the Refractive Media by the Ophthal-
moscope. — Opacities in the refractive media can be best detected
with the ophthalmoscope by the direct method. All opacities look
black in the red pupil, because they intercept the light returning
from the illuminated fundus.

Fig. 30. — Apparent position in the pupil of opacities of the media
when the obser\^er alters his point of view.

Two methods of examination are employed. In the first the
eye is examined at a distance of about 30 cm. ; and the patient
is directed to move the eye in different directions, in order to bring
any peripheral opacities into view and also to localise them. Movable
opacities must lie in the fluid media. They are almost always in the
vitreous humour, and can be seen to float to and fro when the eye
comes to rest. Fixed opacities move with the eye, and lie in the
cornea or lens, or sometimes in the vitreous. Fig. 30 illustrates
the apparent displacement of an opacity in the pupil according
to its position in the media. When the eye of the observer is
opposite the pupil, the opacities 1 to 4 lying on the axis appear as
one point in the centre of the patient's pupil (shown by P). When

36 DISEASES OF THE EYE. [chap. ii.

the eye is rotated upwards, or the observer moves downwards, 2,
which is on the anterior surface of the lens, in the plane of the
pupil, will still appear to be in the same position, while 1, seen in the
direction a b, will seem to be displaced upwards, and 3 and 4 down-
wards, the relative positions being as indicated in the circle at P'.

The second and more delicate method of detecting opacities
consists in examining the eye close up with a convex lens of 20 D,
behind the sight hole of the mirror. Very fine opacities can be
seen in this way, such as minute punctate deposits on the cornea.
Focussing for different levels can be accomplished by approaching
closer for deeper opacities, or by using gradually weaker lenses. Too
strong an illumination interferes with the perception of faint
opacities, hence the plane mirror serves better for this purpose than
the concave.

Prominent portions of the interior of the eye, such as a detached
retina or an intra-ocular tumour, can also be detected, and examined
in detail, by the direct method at a distance, or close up. The
estimation of the refraction by the ophthalmoscope will be dealt
with in chap. xvi.

The electric ophthalmoscope, in which a small electric bulb acts as the
source of light, is a very useful instrument, especially in the examination
by the erect image. The Marple-Morton model, which has a U shaped
mirror, is the best. In its most recent form the current is supplied by a
small dry cell contained in the handle of the ophthalmoscope, which is
also provided with a rheostat for varying the degree of illumination.

THE NORMAL FUNDUS OCULI AS SEEN
WITH THE OPHTHALMOSCOPE.

The Optic Disc or Optic Papilla. — This is the first object to be
sought for by the observer. It presents the appearance of a pale
pink disc, somewhat oval in shape, its long axis being vertical.
Occasionally the long axis lies horizontally, and sometimes the
papilla is circular. The papilla is generally surrounded by a white
ring, more or less complete, called the sclerotic ring, and often, out-
side this again, by a more or less complete black line, the chorioidal
ring (Plate I. Fig. 1). The sclerotic ring is due to the chorioidal
margin not coming quite up to the margin of the papilla, the fora-
men in the chorioid for the passage of the optic nerve fibres being
somewhat larger than that in the sclerotic, and consequently a

PLATE I

{To face page 36)

Yjg. 1. — The optic disc shows a small central physiological cup, a pale
scleral ring, and an outer pigmented or chorioidal ring. Close to the
latter is a cilio-retinal vessel. The macula lutea, of a deeper red
than the rest of the fundus, is surrounded by a delicate oval light-
reflex. The bright spot in the centre of the macula is the fovea
centralis.

YiQ. 2. — The patch of opaque nerve-fibres is of a brilliant white ; it is
prolonged in the direction of some of the vessels, and presents a
characteristic finely striated border. Note the dark colour of the
disc, which is chiefly a result of contrast. The vision was the same as
in the unaffected eye.

Plate I.

Fig. 1. Normal Disc and Macula.

L.W.

Fig. 2. Opaque Nerve Fibres.

CHAP. II.] THE OPHTHALMOSCOPE. 37

narrow edging of the white sclerotic is exposed. The chorioidal
ring is the result of a hyper-development of pigment at the margin
of the chorioidal foramen.

The complexion of the optic disc results from the pink hue
derived from its fine capillary vessels, combined with the whiteness
of the lamina cribrosa, and the bluish shade of the nerve fibres.
It is frequently not equal all over, but is paler on the outer side,
where the margin is more defined, and where the nerve fibres are
fewer than on the inner side. The apparent colour of the papilla
depends also upon the complexion of the rest of the fundus. If
the latter be highly pigmented, the papilla appears pale in contrast ;
while, if there be but little pigment in the chorioid, the papilla may
appear very pink. The complexion of every normal papilla is
not identical, and care must be taken not to make the diagnosis
" Hyperaemia of the papilla " where merely a high physiological
complexion is present. The upper and lower margins of the papilla
are often, especially in young people, a little indistinct, and show a
delicate striation by the direct method of examination. This may
be greatly exaggerated in hypermetropes, and has in them been
sometimes erroneously taken for optic neuritis.

A physiological excavation of the optic papilla is often met with
as a white depressed area (Plate I. Fig. 1) either on the temporal
side or in the centre of the papilla, and can be recognised by the
parallax 1 which may be produced, and by its colour. When the
excavation is very deep, one may sometimes observe the lamina
cribrosa in the form of grey spots (the nerve fibres) surrounded by
white lines (the fibrous tissue of the lamina).

A physiological excavation differs from a pathological excavation,
in that it does not reach the margin of the papilla all round. It is
caused by the crowding over of the nerve fibres to the inner side of
the papilla. Yet sometimes, a healthy optic papilla will be met
with, in which the excavation apparently reaches the margin all
round.

The Normal Retina is so translucent that it cannot be seen,
the red reflex being due to the chorioidal vessels. At most, a shim-
mering reflection of shot-silk appearance is obtained from it, par-
ticularly about the region of the yellow spot (Plate I. Fig. 1) and

^ For explanation of the parallax see chap. ix.

38 DISEASES OF THE EYE, [chap. n.

along the vessels, but also towards the equator of the eye, and
especially in dark eyes, and in young people.

A peculiar, but physiological, appearance known as opaque nerve
fibres (Plate I. Fig. 2) is occasionally seen. It is produced by some
of the nerve fibres forming the internal layer of the retina regaining
the medullary sheath on the distal aspect of the lamina cribrosa,
or near the margin of the papilla, which they had lost in the optic
nerve just before entering the lamina cribrosa ; the rule being
that the nerve fibres lose their medullary sheath at the latter place
definitely, and enter the retina as axis cylinders only, and hence
are quite translucent. But in these cases the nerve fibres reflect
the light strongly, giving the effect of an intensely white patch, com-
mencing at the disc, extending more or less into the surrounding
retina, and terminating in a brushlike extremity. In such cases
the optic papilla appears to be darker than normal, partly from
contrast. This appearance is constant in the rabbit's eye.

The Macula Lutea is generally seen as a bright oval ring with its
long axis horizontal, this ring being probably a reflex from the
surface of the retina (Plate I. Fig. 1). It is remarkable that this
halo is not visible with the direct method of examination — a fact due
probably to the illumination being much weaker than with the
indirect method. The area inside the ring is of a deeper red than
the rest of the fundus, and at its very centre there is an intensely
bright point, the fovea centralis. The ring is not seen in old people.
The macula lutea is situated to the temporal side of the optic disc,
about two disc diameters away from it, and slightly above the lower
margin of the disc.

The General Fundus Oculi surrounding the optic papilla and
macula lutea varies a good deal in appearance, according to the
amount of pigment contained in the chorioid and in the pigment-
epithelium layer of the retina. 1. If there be an abundant supply
of pigment in each of these positions, the chorioidal vessels are
greatly hidden from view, and the effect is that of a very dark red
fundus. 2. If there be but little pigment in the pigment-epithelium
layer, the larger chorioidal vessels may be visible, and the fundus
may appear to be divided up into dark islands surrounded by red
lines. 3. If the individual be a blonde, there is little pigment either
in the pigment-epithelium layer or in the chorioid, and the fundus
is seen of a, very l)right red colour, the chorioidal vessels down

CHAP. II.]

THE OPHTHALMOSCOPE.

to their fine ramifications being discernible. In albinos even the
chorioidal capillaries may be seen. The chorioidal vessels are flat,
they vary much in size, and anastomose freely (see Plate IV. Fig. 1,
and Plate IX. Fig. 2).

The Retinal Vessels. — The arteries are recognised as thin bright
red lines running a rather straight course, in the centre of each of
which is a light-streak. As to the cause of this light-streak there
is considerable divergence of opinion. Some attribute it to reflection

Fig. 31. {Groefe and Scemisch.)

a.n.s., Art. nas. sup. ; aji.i., Art. nas. inf. ; a.t.s., a.t.i., A. temp. sup. and inf. ; v.n.s., v.n.i.
Ven. nas. sup. and inf. ; v.t.s.,v.t.i.,\en. temp. sup. and inf. ; a.m.c.,v.m.e.,^^vt. and ven. median
a.m., v.ni.. Art. and ven. macularis.

from the coats of the vessel, or from the surface of the blood column ;
while others believe that the light is reflected from the fundus
through the vessel, which then acts as a very strong cylindrical
lens. This light-streak divides the vessel into two red lines. The
vems are darker, wider, and more tortuous in their course than the
arteries, and, their coats not being so tense, the light-streak on them
is very much fainter.

40 DISEASES OF THE EYE. [chap. ii.

On reaching the level of the nerve-fibre layer of the retina the
central artery and vein divide into a principal upper and lower
branch. This first branching often takes place earlier in the vein
than in the artery, and the former may even branch before appearing
on the papilla, as in Fig. 31. The second branching may take
place in the nerve itself ; and when this occurs it will appear as
though four arteries and four veins sprang from the optic papilla ;
but more usually this branching occurs on the papilla, as in Fig. 31.
The vessels produced by this second branching pass respectively
towards the median and temporal side of the retina, and are termed
the Art. and Ven. nasalis and temporalis sup. and inf. {vide Fig. 31).
The temporal branches run in a radial direction towards the anterior
part of the retina. A small horizontal branch, the Art. and Ven.
mediana, from the first principal branches is found passing towards
the nasal side of the retina. The temporal branches do not run in
a horizontal direction, but make a detour round the macula lutea,
sending fine branches towards the latter. Two or three minute
vessels from principal branches run directly from the papilla toward
the macula lutea, and around the macula lutea a circle of very
fine capillary vessels is formed which cannot be distinguished with
the ophthalmoscope ; but no vessels run to, or cross over, the
fovea centralis itself. The retinal arteries do not anastomose,
nor do the larger retinal veins. The small retinal veins have some
slight anastomoses near the ora serrata. Occasionally, a vessel
emerges near the margin of the disc, usually at the temporal side.
It arises from the ciliary vessels, and is hence called a cilio-retinal
vessel (Plate I. Fig. 1).

No pulsation of the arteries is observable in the normal eye.
In the larger veins near or on the optic papilla, or more usually
just at their point of exit, a pulsation may sometimes be seen.
This venous puliation is due to the following sequence of events ;
systole of the heart ; diastole of, and high tension in, the retinal
arteries ; consequent increased pressure in the vitreous humour ;
communication of this to the outside of the walls of the retinal
veins, impeding the flow of blood through them, especially in their
larger trunks, which offer little resistance, or at their exit from the
eye, where the blood pressure is lowest ; and in this way the veins
are emptied — the blood gradually coming on from the capillaries
overcomes the resistance, and the veins are for a moment refilled.

CHAP. II.] THE OPHTHALMOSCOPE. 41

The phenomenon can be most readily observed, if the normal tension
of the globe be increased by gentle pressure with the finger during
the ophthalmoscopic examination. By increasing the pressure the
arteries also can be made to pulsate even in a normal eye, but
such a degree of pressure is dangerous.

CHAPTER III.

DISEASES OF THE CONJUNCTIVA.

The Conjunctiva, or Conjunctival Sac, whicli is a mucous membrane,
may for descriptive purposes be divided into three portions : the
palpebral, which forms a smooth lining for the inner surface of the
eyelids ; the bulbar, loosely covering the sclerotic ; and the retro-
tarsal folds, uniting ^these two, which form the sulcus or fornix,
upper and lower. When the bulbar conjunctiva reaches the margin
of the cornea it overlaps the latter sHghtly, and this overlapping
portion is known as the limbus conjunctivae, or cornese. At the inner
angle or canthus there is a vertical crescentic fold, the plica semi-
lunaris, on the nasal side of which is a rounded mass of modified skin
called the caruncle.

On the palpebral surface of the upper lid close to, and running
parallel to the margin, is a shallow groove, called the subtarsal sulcus.
Some adenoid tissue exists in the fornices of the normal conjunctiva,
and follicles are sometimes found, the latter being probably due to
the constant irritation to which the conjunctiva is exposed. The
conjunctiva is lubricated by the secretion from the glands and
conjunctival epithelium. The lacrimal fluid, which has only a very
slight bactericidal action, merely exercises a mechanical effect which
consists in the washing away of foreign particles.

The Examination of the Conjunctiva.— Simple inspection in good
diffused daylight, the patient facing the window, is better than
artificial illumination. The whole of the mucous membrane should
be examined, and for this purpose the lids must be everted. The
eversion of the lower lid is a simple matter, but a certain amount of
practice is required in the case of the upper lid.

Eversio7i of the upper lid. — The surgeon should face the patient
and direct him to look down and to continue looking down, in order
to render the upper edge of the tarsus accessible. The point of

CHAP. III.

THE CONJUNCTIVA.

the thumb of one hand is then placed on the outer surface of the
lid, just above the tarsus, and with it the skin is drawn a little

Fig. 32. — First steps in eversion
of upper lid.

Fici. 33. — Everted lids held in
position with one hand.

upwards and backwards ; this causes the margin of the lid to start
forwards. The eyelashes (or the margin of the Hd) are then taken
between the thumb and forefinger of the other hand (Fig. 32) and

Fig. 34. — Method of examining a child's eye.

raised upwards, while the thumb above is depressed. The thumb
which acts as the depressor should not be taken away too soon, a
mistake often made by beginners, and it is better to slide it away

DISEASES OF THE EYE.

[chap. III.

sideways. In case of failure a probe or glass rod can be used instead
of the thumb. When everted, the lids can be retained in position
by one hand (Fig. 33), while ap-
plications are being made to the
conjunctiva.

The method of examining the con-
junctiva and cornea in infants and
children is shown in Fig. 34. The
head is firmly held between the
surgeon's knees. The conjunctiva
is easily inspected, as the lids be-
come everted on merely attempting
to open the eye by pulling on the
skin near the lid margins. In order
to examine the cornea, the lids must
not be allowed to become everted,
but must be separated with the points of the fingers placed on the
ciliary margins as shown in Fig. 35. The cornea at first rotates
under the upper lid, but soon comes down into view. Care must be
taken to avoid injuring the cornea with the finger nails, or using too
great pressure on the eye, which might rupture a corneal ulcer.
The surgeon too must beware lest retained secretion should spurt
up into his own eyes.

The normal conjunctival surface of the upper lid is smooth.

Fig. 35.— Method of exposing
a child's eye.

Fig. 36. — Examination of retro-
tarsal folds of upper lid.

Fig. 37. — Exposure of upper
fornix ; lid everted and
raised with retractor.

yellowish-pink in colour, and the conjunctiva is adherent to the
tai'siis The small l)i'anches of the tarsal arches can be seen runninjj;

Plate II.

Fig. I. Conjunctival Congestion. Fig. 2. Ciliary Congestion (Iritis).

Fig. 3. Ciliary Congestion
(Phlyctenular).

Pig, 4. Ciliary Congestion
(Glaucoma).

Fig. o. Congestion in Scleritis. Fio. 0. Ecchymosis of Conjunctiva.

PLATE II

(To face page 4.1)

TYPES OF CONGESTION

Fig. 1. — Conjunctival congestion associated with catarrhal conjunctivitis.
The vessels are bright red, tortuous, and easily seeii. The congestion
is greatest towards the periphery.

Fig, 2. — The delicate pink zone of ciliary congestion immediately sur-
rounds the cornea, and is composed of very minute vessels which
are not easily seen separately. A pointed posterior synechia renders
the pupil irregular, and on the iris is a reddish yellow tumour (a
gumma).

Fig. 3. — These small patches of ciliary congestion precede or follow the
development of marginal phlyctens.

Fig. 4. — The ciliary congestion here consists of a fine venous reticulum.
Note the few large tortuous veins, and the dilated and greenish pupil.

Fig. 5. — Note the patch of deep violet congestion, with slight diffuse
swelling, the discoloration of the sclerotic above and below, and the
irregular outline of the cornea due to the encroachment of ' sclero-
tising opacities.'

Fig. C. — The appearance of the effusion of blood under the conjunctiva
is easily distinguished from a localised congestion.

■■•■■-.;!• >■ : I" IM lilUi, ■

' oi 9ub aenioo edi lo

CHAP, iii.l THE CONJUNCTIVA. 45

in a vertical direction, and the Meibomian glands appear as yellowish
or grey lines at right angles to the ciliary margin of the lid. The
stndent should note the appearance and thickness of the edge of
the normal tarsus when everted. Figs. 36 and 37 illustrate the
method of inspecting the retro-tarsal folds and fornix. The double
eversion (Fig. 37) is necessary in cases of suspected foreign bodies in
the fornix.

The blood-vessels of the conjunctiva consist of the posterior
conjunctival vessels derived from the palpebral vessels, and the
anterior conjunctival vessels which pass backwards from the anterior
ciliary vessels. In general affections of the conjunctiva the former
are chiefly involved. Engorgement of the vessels of the conjunc-
tiva is known as conjunctival congestion (Plate II. Fig. 1), in order
to distinguish it from ciliary congestion, which accompanies diseases
of the cornea and iris. It is bright red in colour, most marked
towards the fornix, and is formed by a network of large, tortuous,
superficial vessels, which move with the conjunctiva. Ciliary con-
gestion (Plate II. Fig. 2) on the other hand is limited to the cir-
cumcorneal area, and diminishes towards the periphery. It is due
to engorgement of the episcleral branches of the anterior ciliary
vessels. It is pink or violet in colour, and is composed of minute
straight radiating vessels, which are frequently indistinguishable
to the naked eye as separate vessels. They are situated under the
conjunctiva, and cannot be moved with it. In severe inflammations
of the eyeball, such as a purulent ulcer of the cornea, these two
forms of congestion are frequently present together.

Hyperaemia of the Conjunctiva.— In this condition the blood-
vessels of the palpebral conjunctiva are especially engaged. A
slight serous exudation sometimes takes place, which may raise the
conjunctiva around the cornea, a condition known as chemosis
{xatiw, to gape open). Yet there is not any abnormal discharge
from the conjunctiva, and herein lies the chief clinical difference
between this affection and simple conjunctivitis. Of course a
hyperaemia may be the earliest stage of a conjunctival in-
flammation.

Causes. — Foreign bodies. Dust, foul air, or air loaded with
tobacco-smoke. Alcoholic excesses. Accommodative asthenopia.
Stenosis lacrimalis, and other forms of lacrimal obstruction. The
use of unsuitable spectacles, or the use of the eyes for near work

46 DISEASES OF THE EYE. [chap. m.

without spectacles, "wlien the conditiou of the accommodation {e.g.
hypermetropia, presbyopia) requires them.

Symptoms. — Tlie eyes are irritable. There is lacrimation and
photophobia, with hot, burning sensations, and sensations as of
a foreign body in the eye, and the eyelids feel heavy. All these
symptoms are aggravated in artificial light.

Treatmeyit. — In addition to the removal of the cause, the in-
stillation of mild astringents or of a drop of tincture of opium and
distilled water in equal parts morning and evening will be found
beneficial. Adrenaline has no permanent effect on the hypersemia.
The eyes should be protected from the glare of light by dark glasses,
and out-of-door exercise is to be recommended.

Conjunctivitis in general. — The term Ophthalmia is commonly
used as a synonym of Conjunctivitis, ^ which differs from mere
hypersemia in the presence of abnormal secretion. Apart from
mechanical or chemical irritation, inflammation of the conjunctiva
is almost always caused by micro-organisms gaining access to the
conjunctival sac ; or perhaps, in some cases, by the sudden develop-
ment, under favourable conditions, of those which had been already
present in a latent condition. They can easily be detected in the
discharge, except sometimes in the rare cases of metastatic or endo-
genous origin, and are the cause of its infectious nature. Sporadic
cases are very common, but the disease frequently spreads through
the members of a household, or occurs as an epidemic. Infection
takes place by the direct transference of the secretion from person to
person, or indirectly by a common use of the same articles by different
people. Inflammations of the conjunctiva are met with in patients
of all ages, and at all seasons of the year ; but some forms are more
common in the spring and autumn. The palpebral conjunctiva
is often affected when the bulbar portion remains normal, and the
conjunctiva of the lower lid is more frequently attacked than that
of the upper lid.

Differential Diagnosis. — The milder forms of conjunctivitis are
apt to be mistaken, by those who are inexperienced, for iritis and
vice versa, but with care there should be no difficulty in distinguish-

1 Blepharitis is sometimes called Ophthalmia tarsi, and to this there
can be little objection, but the name Sympathetic Ophthalmia is liable
to mislead, as this disease has nothing to do with the conjunctiva, being
in fact an inflammation of the uveal tract.

OHAP. TIT.] THE CONJUNCTIVA. 47

ing between the two affections. Conjunctivitis is accompanied by
conjunctival congestion, the secretion is muco-purulent, and if
not in sufficient quantity to be detected in the conjunctival sac,
its presence is indicated by the fact that the Hds are gummed to-
gether in the mornings. The pain is superficial and limited to the
eye itself (sensation of foreign body, heat, itching). Vision is not
aflfected, except temporarily by secretion on the surface of the
cornea, which is easily removed by rubbing the lids over the eye.
Iritis, on the other hand, is recognised by the presence of ciliary
congestion, lacrimation instead of a sticky secretion, and by the
character of the pain, which is neuralgic and circumorbital. More-
over, the vision becomes impaired at a very early stage of the disease.
The ultimate diagnosis rests of course on the appearance of the iris
and on the effect of atropine (see chap. vii.).

Varieties of Conjunctivitis. — Although an accurate diagnosis
of the different forms of conjunctivitis depends on the discovery
of the particular micro-organism in each case, nevertheless the usual
classification, which is based on clinical appearances, must for the
present be adhered to, partly because these appearances are suffi-
cient in most cases to indicate the line of treatment required, but
chiefly because the type of inflammation excited by a given microbe
is not sufficiently constant. In the majority of cases no doubt
a definite group of symptoms is associated with a particular micro-
organism, but occasionally the reaction takes a different form.^
Again, one and the same clinical picture may be produced by different
micro-organisms. In exceptional cases, too, a mixed infection
may take place.

From a clinical point of view, then, conjunctivitis is divided
into different varieties, depending on the nature of the discharge,
the pathological changes in the tissues, and the severity of the
symptoms. In Catarrhal Conjunctivitis, which may be acute or
chronic, the discharge is muco-purulent in character, whereas in
Purulent Conjunctivitis pure pus is secreted. The discharge becomes
fibrinous and coagulates to form a membrane, lying on the surface
of the conjunctiva, in the so-called Croupous variety, or it extends
into the substance of the tissues in the Diphtheritic form. In some

^ This may be due to altered conditions, such as differences in the
resistance of the tissues or blood, or to variations in the degree of virulence
of the microbe.

48 DISEASES OF THE EYE. [chap. hi.

cases (Spring Catarrh) the discliarge contains kirge numbers of
eosinopliil cells. All inflammations of the conjunctiva are accom-
panied by more or less increase of the normal lymphoid tissue,
which is of a diffuse character, l)ut in certain cases lymphoid masses
are formed which become visible to the naked eye, as in Follicular
and Granular Ophthalmia. In Phh/ctenular Conjunctivitis small
papules, or pseudo-vesicles, are found on the bulbar conjunctiva.
Severe cases of conjunctivitis are often attended with slight swelling
of the preauricular gland ; but in the condition known as ParinaucVs
Conjunctivitis the glandular enlargement is considerable, and reddish
^vegetations form on the palpebral conjunctiva. Traumatic Con-
junctivitis may be produced by physical or chemical causes, and
inflammation of the lacrimal sac frequently extends to the conjunc-
tiva. In rare cases a Metastatic Conjunctivitis due to endogenous
infection has been observed. Finally Eczema, Impetigo, and some
of the exanthemata (Measles, Scarlatina, Small-Pox) are frequently
accompanied by conjunctivitis.

The Bacteriology of Conjunctivitis. — The micro-organisms which
are commonly met with as the active causes of conjunctivitis are
not very numerous. The following is a list of them, with the clinical
type of disease to which each most frequently gives rise : —

Bacilli.

The Koch-Weeks B. — (Acute Contagious Conjunctivitis). The
Diplobacillus of Morax — (Subacute Angular C). The Diphtheria
B.— (Membranous C).

Cocci.

The Gonococcus. — (Purulent C). The Pneumococcus. — (Cat-
arrhal C). Streptococcus. Staphylococcus albus et aureus.

The last two most frequently occur as part of a mixed infection,
along w4th the gonococcus and the diphtheria bacillus. They are,
however, also found, alone or together, in the conjunctivitis (often
membranous) which accompanies impetigo of the face, or which
follows scarlatina, but they have never been known to cause an
epidemic.

The Xerosis Bacillus (see Xerosis), which is non-pathogenic, is
very frequently present in the normal conjunctiva and in the

rnAP. III.] THE CONJUNCTIVA. 40

Meibomian secretion ; but it should also be remembered that some
of the pathogenic forms, such as the staphylococcus, pneumococcus,
and, it is stated by some, the streptococcus, are also found (especially
the first named) in conjunctival sacs devoid of all signs of irritation.
In fact the normal conjunctiva is rarely free from micro-organisms,
and the results obtained by cultures may vary from day to day.
According to Mayou there are fewer micro-organisms in the upper
fornix than in the lower.

The epithelium of the conjunctiva offers a certain resistance to
the entrance of organisms, and hence many of them will not set
up an inflammation unless there be a superficial loss of substance.

All the above, with the exception of the gonococcus, the Weeks
bacillus, and the diplobacillus, stain by Gram's method.^

The number of micro-organisms does not always correspond
with the amount of discharge, and in some instances none can be
found. We have recently had a case of this kind in which, although
the discharge was profuse, both cover-glass preparations and at-
tempts to obtain cultures gave negative results on three different
occasions. The etiology of such cases is unknown ; they may
perhaps be due to toxins circulating in the blood or to organisms
as yet undiscovered.

In addition to those which have been mentioned, other micro-
organisms have occasionally been found in conjunctivitis. In the
case of some of them it is very doubtful if they were the exciting
cause of the condition of the conjunctiva w4th which they were
associated. The most important varieties will be briefly referred
to as we proceed.

Catarrhal, or Simple Acute, or Muco-purulent Conjunctivitis.—
In mild cases the affection is confined to the palpebral conjunctiva,
often even to the conjunctiva of the lower lid ; but in the severer
cases it extends to the bulbar conjunctiva. In the latter event
the lids may be slightly hyperaemic and swollen. Both eyes are
usually affected, either simultaneously or at a short interval.
Lymph follicles and enlarged papillae are sometimes present. There

1 For clinical work, in most cases, cover-glass smears stained by Gram's
method, followed by a counter-stain, such as weak Carbol-Fvichsin, or
Loeffler's ^Methylene Blue, will suffice, but in some cases the identity of the
particular microbe can only be established by cultures and inoculation
experiments.
4

60 DISEASES OF THE EYE. [chap. hi.

is a sticky, thin, mucous, or muco-purulent secretion which is often
visible in the form of strings in the lower fornix. It dries on the
eyelids at night so as to fasten them together when the patient
awakes in the morning, and sometimes produces ulceration of the
intermarginal portion of the eyelids (intermarginal blepharitis).
In some of the very mildest cases this stickiness, or gumming, on
awaking in the morning is a valuable diagnostic sign, for in such
cases it is difficult or impossible to recognise by inspection the very
slight variation from the healthy appearance of the conjunctiva.

In the severer cases the papillae are markedly swollen, and may
even conceal the Meibomian glands from view. Also, one often
sees small ecchymoses in the bulbar conjunctiva, especially in certain
epidemics ; but these have no serious import.

Minute grey infiltrations which may break down and form small
ulcers sometimes appear at the margin of the cornea, more especi-
ally in old people. When there are many of them they may become
confluent and form a small grey crescent, which ulcerates, and thus
a crescentic marginal ulcer is formed, and very occasionally such
an ulcer is followed by iritis.

The catarrh may become chronic (p. 56). The chronic form of
the disease is much less contagious than the acute, which frequently
affects a whole family or may result in an epidemic.

The Symptoms are those of a severe case of hyperaemia (sensa-
tions of sand in the eye ; hot, burning sensations ; weight of the
eyelid), with the addition of the annoyance consequent on the
secretion, which, by coming across the cornea, may cause momentary
clouding of sight. Photophobia is not generally severe unless there
be some corneal complication. The symptoms are worse at night,
or by artificial light, and are much less troublesome when the eyes
are exposed to the open air.

Causes. — Direct infection with secretion, or increase of the micro-
organisms already present in the conjunctival sac, favoured by
conditions which lower the resistance of the tissues, either locally
by causing hyperaemia, or generally through the system (impure
air, exposure to cold, etc.). Perhaps also the microbes are more
widespread or more virulent at certain times, as in the spring or
autumn. Some of the above-mentioned causes act, no doubt in
combination, in the conjunctivitis which accompanies impetigo,
scarlatina, measles, and smallpox.

Diplohacillus {Momx and Axen- Koch-Weeks bacillus. Secretion

jeld). From a case of subacute from acute conjunctivitis. A few
angular conjunctivitis. deeply stained Xerosis h. are also

present.

Pneumococciis. From a case of Gonococcus. From a case of

catarrhal conjunctivitis. ophthalmia neonatorum.

Xerosis bacillus. Culture from Xerosis bacillus. Culture, diph-

normal conjunctiva, showing iew theroid form,
clubs.

From preparations and drawings by L. W.

CHAP. III.] THE CONJUNCTIVA. 53

The Koch-Weeks hacillus produces an acute contagious con-
junctivitis, which chiefly attacks young people, and occurs most
frequently in an epidemic form.

It is more severe in adults than in children ; and is often attended
by an erythematous condition of the upper lids, or even by slight
oedema. Ecchymoses occur on the bulbar conjunctiva. The pre-
auricular glands are sometimes enlarged. The Koch-Weeks
bacillus may be easily overlooked, as it is a very fine bacillus
and stains feebly. This form of conjunctivitis is not common in
Ireland.

The Pneumococcus is responsible for a mild form of catarrhal
ophthalmia, occurring in children or adults, sometimes in small
epidemics. A characteristic sign of this variety of conjunctivitis is
(according to Morax) an oedema or rose-coloured hyper^emia con-
fined to the margin of the upper lid. It also gives rise to minute
ecchymosis of the bulbar conjunctiva. The secretion is at times
fibrinous. This variety does not appear to be as common in the
United Kingdom as elsewhere. It is of short duration (ten days
or so), and can be readily cured.

The conjunctivitis associated with impetigo sometimes assumes
a mild catarrhal form. Both Strepto- and Staphylococci are found
to be present. The former can no doubt set up conjunctivitis, but
attempts to produce conjunctivitis in man with virulent cultures
of staphylococcus aureus have proved ineffectual.

In rare cases catarrhal conjunctivitis has been caused by the
Diplococcus Intracellularis Meningitidis, not necessarily accompanied
by meningitis.

In influenza epidemics conjunctivitis sometimes occurs along
with the other symptoms, or it may precede them. It is due to the
Influenza Bacillus, which is shorter and stouter than the Weeks B.
but is difficult to distinguish from the latter. It is much rarer in
adults than in children.

Cases of conjunctivitis have also been observed, which were
undoubtedly caused by the hay bacillus {B. Suhtilis.) In all of them
particles of earth had found their way into the eye.

The Prognosis of catarrhal conjunctivitis is good, if there be no
reason to suspect that the mild form is but the commencement of
a more severe inflammation. The infiltrations, and even the ulcers
which sometimes form at the margin of the cornea are not often

54 DISEASES OF THE EYE. [chap. hi.

of serious import, and usually heal, according as the treatment
restores the conjunctiva to health.

Treatment. — It will be advisable here to make a few observations
on the treatment of conjunctivitis in general. Patients should
always, in the first place, be warned of the danger of infecting
other persons. And in order also to avoid re-infecting themselves,
droppers should be sterilised, or at least should not be brought into
contact with the eye when being used. For bathing the eye sponges
should be avoided, and small pieces of lint employed, which must be
burnt immediately after use. Bandages should not be worn, nor
should the patient be confined to the house, unless in severe or
complicated cases.

In catarrhal conjunctivitis cold or iced compresses, with the use
of a 1 in 5000 solution of sublimate as a lotion, should be used
frequently at the onset, and in mild cases will alone bring about a
cure. But the habit, which some patients so readily acquire, of
bathing the eyes frequently with cold water should not be permitted,
for it is deleterious to the conjunctival affection. When in a day or
two the irritation and swelling have somewhat subsided — or from
the very commencement, if there be discharge — a solution of nitrate
of silver, of from 5 to 10 grains to §j, should be applied by the
surgeon to the palpebral conjunctiva with cotton wool twisted on
the end of a small piece of stick, such as is used for matches, the lid
being well everted. The excess may be neutralised with solution
of common salt. The neutralisation with salt water checks pro-
longed action of the nitrate of silver, and obviates conjunctival
staining (called Argyrosis, from apyvpos, silver) when the treatment
is a lengthened one. The application is to be repeated after twenty-
four hours, by which time the slight loss of epithelium, the result
of the superficial slough, will have been repaired. Immediately
after such an application cold sponging or iced compresses are useful,
and grateful to the patient. Gentle removal of the loose coagula
also gives much relief.

Of the organic silver salts the best are protargol, in 5 to 20 per
cent sol., sophol 5 per cent., and argyrol 25 per cent. They do
not coagulate albumen, and are therefore supposed to have greater
penetrating power, and are practically painless. Personally we
still rely on the nitrate in preference to them.

Even weak solutions of nitrate of silver as eye-drops to be used

CHAP. III.] THE CONJUNCTIVA. 55

at home by the patient, should be avoided, for staining of the con-
junctiva is very apt to be caused in this way. Protargol and argyrol
also cause staining.

Subconjunctival injections of Potassium Iodide, 30 per cent, to
saturated sol., help to remove argyrosis. Three or four minims only
are injected at a time on account of the rather severe reaction.

Should the surgeon be unable to see the patient daily, astringent
and antiseptic eye-drops are very beneficial, and indeed often effect
a cure. Sulphate of zinc (gr. ij to the 5J), with or without Tinct.
Opii, 3jj alum (gr. iv to 5J), tannic acid (gr. v to viij to §j) are those
which are most commonly used. They may be combined with
boracic acid in saturated solution, corrosive sublimate (1 — 5000),
or oxycyanate of mercury (1 — 2000). Acetate of lead (gr. 1 or ij to
5J) can also be prescribed, provided the cornea be intact; other-
wise deposits of lead are liable to form in it.

A weak boracic acid ointment should be applied along the
margins of the lids at bedtime. It prevents the adhesion of the
lids in the morning, which is not only unpleasant to the patient,
but also prevents free drainage of the secretion during sleep.

Diplobacillary or Angular Conjunctivitis.— This form of in-
flammation requires a description apart, not only because it pre-
sents a definite clinical picture, but also because it readily yields,
to a particular line of treatment. It presents the appearance of a
subacute or chronic conjunctivitis, the congestion being limited to
the palpebral conjunctiva, more especially of the lower lid, and to
the caruncle. The secretion is very scanty, and makes its appear-
ance most commonly round the inner canthus, as a slight greyish-
white collection, but still the lids are often stuck together in the
mornings. The most characteristic sign, and one which has given
rise to the name " Angular," is a peculiar moist hyperaemia, with
superficial excoriation, of the skin at the margin of the lids, which
usually surrounds the canthi, especially the inner canthus, although
the whole margin of the lids may be affected by it. In very mild
cases this condition of the skin may be absent. The subjective
symptoms consist in sensations of heat, pricking, and itching, and
are always much worse in the evening. Corneal affections are
not common, but occasionally small superficial marginal ulcers
occur ; and, less frequently still, severe central ulcers with hypopyon
(see chap. v.).

56 DISEASES OF THE EYE. [chap. hi.

The disease is chiefly met with in adults, but it also occurs in
children, in whom it may even cause blepharitis. We have often
seen it too as a complication of trachoma in the later stages.

Cause. — The exciting cause is the Diplobacillus of Morax and
Axenfeld, the largest of the micro-organisms found in the con-
junctival sac (see p. 51). It grows only on sohd media containing
serum, in which it produces very characteristic clear depressions.
Inoculation easily succeeds in reproducing the disease, but only in
human beings. The diplobacilli have also been found in the nose,
but it has not been definitely ascertained whether or not they
reach the latter through the nasal duct.

Treatment. — This affection shows no tendency to spontaneous
cure, and, if neglected, it may last for many months ; but fortunately
we have in sulphate of zinc an unfailing remedy. Solutions of from
4 to 10 grains to the ounce will effect a cure in ten days or so, and
are much more efficacious than very weak solutions, and are not
very painful. Cocaine may be added for patients of nervous tem-
perament. In order to prevent a relapse, the treatment should
always be continued for about a week after the subjective symptoms
have disappeared. If the lids be tender, an ointment of oxide of
zinc (10 per cent.) and icthyol (2 to 5 per cent.) is very useful. The
sulphate of zinc does not kill, but merely checks the growth of the
bacilli, hence the necessity for prolonging the treatment after an
apparent cure.

In rare cases of idiosyncrasy to zinc sulphate, resorcin in 2 or
3 per cent, aqueous solution gives good results.

Chronic Simple or Chronic Catarrhal Conjunctivitis.— This form
of conjunctivitis occurs in adults and old people, and is extremely
obstinate, often lasting for years, and sometimes, with or without
intermissions, even for a lifetime. The objective signs vary in
degree from those of simple hypersemia without apparent secretion
to a moderate catarrh with muco-purulent discharge. But they
are never so pronounced as in the acute form of the disease, and
the bulbar conjunctiva is seldom much injected.

The subjective symptoms resemble those which have been men-
tioned in the descriptions of hypersemia and acute catarrh. They
are always worse in the evening, and patients often complain that
when they attempt to read, the upper lids feel heavy and inclined
to close, so that they feel sleepy. A sensation of dryness of the eye-

CHAP. III.] THE CONJUNCTIVA. 57

ball is also experienced, when the secretion is scanty or absent. In
many cases, however, the sensations complained of are much in
excess of the objective appearances.

In the later stages, the conjunctiva, in muco-purulent cases,
becomes rough or velvety, from hypertrophy of the papillae, and
ectropion of the lower lid, epiphora, and blepharitis may result.
The skin of the lower lid, from the constant irritation caused by
the discharge, becomes eczematous and stif?, the inner end of the
lid then becomes everted, so that the punctum lacrimale no longer
lies in normal contact with the eyeball, and this, together with
narrowing of the punctum and canaliculus by the hypertrophied
conjunctiva, leads to epiphora, which again intensifies the irritation
of the skin, and still further increases the ectropion. Marginal ulcers
of the cornea, too, are liable to occur in old people with chronic
conjunctival catarrh.

The Causes of this affection are very numerous. It seldom
originates in an acute catarrh, but more commonly begins gradually,
and owes its origin to local irritation of the conjunctiva or to con-
stitutional causes. Amongst the former are included dust, chemicals,
smoke, bad ventilation, exposure to heat or steam, in- turned eye-
lashes, infection from the lacrimal sac, errors of refraction, prolonged
reading by artificial light, sleeplessness, and constant exposure to
wind or rain. Less well-known causes are : inefficient closure of
the eyelids at night, so that a portion of the eyeball remains exposed
to the atmosphere ; purulent infection of the ducts of the Meibomian
glands, or soHd infarcts in the Meibomian glands or in small con-
junctival cysts. In many cases no definite cause can be assigned.

Treatment is often unsatisfactory, partly owing in many cases to
the impossibility of removing the cause when this is due to the
nature of the patient's occupation. Indications for treatment are
provided by a consideration of the above-mentioned causes. Atten-
tion should also be paid to the general health ; relief of constipa-
tion ; avoidance of alcoholic stimulants ; correction of errors of
refraction and presbyopia ; treatment of the lacrimal apparatus
(chap, xix.) and of ectropion (chap, xviii.). In case of defec-
tive closure of the lids, a bandage at night may be applied. Sup-
puration in the Meibomian ducts can be effectually relieved by
expression of their contents, daily if necessary. Any solid white
infarcts^ if they project above the surface, should be picked out of

58 DISEASES OF THE EYE. [chap. hi.

the palpebral conjunctiva with the point of a needle or knife. With
regard to local applications, astringents are the most useful, but
they should not be too irritating. Nitrate of silver may be necessary
if there be discharge or hypertrophy of the conjunctiva. Protargol,
argyrol, or other organic silver salts are less painful, but the possibility
of causing argyrosis should not be forgotten. Other useful astrin-
gents are alum in solid stick, or in J to 1 per cent, solution ; copper
sulphate ; lead subacetate ; tannic acid in solutions containing
1 or 2 grains to 5J. Boracic acid too may be used in saturated
solution, but it is the mildest and least active of all. Adrenaline
gives only temporary relief. Frequent use of cocaine is not to be
recommended, as it renders the cornea vulnerable to micro-organisms
by deranging its epithelium. Very mild cases of diplobacillary
conjunctivitis may not be accompanied by the characteristic ex-
coriation of the skin, and may then resemble a simple chronic
conjunctivitis ; but here a bacteriological examination would at
once establish the diagnosis and suggest the appropriate treatment.

Acute Blennorrhoea of the Conjunctiva, or Purulent Ophth-
almia. — This very dangerous affection, which statistics show to be
one of the commonest causes of blindness, is usually seen either as
gonorrhoeal ophthalmia or as blennorrhoea neonatorum.

Etiology. — In gonorrhoeal ophthalmia the etiological moment
is the introduction of some of the specific discharge from the ure-
thra or vagina into the conjunctival sac ; while in blennorrhoea
neonatorum the infection is believed to take place, either during
or just after the passage of the head through the vagina, by ab-
normal secretion from the latter finding its way into the infant's
eyes. A few instances have been observed of infants born with
the disease. Prolonged labour, due to early rupture of the mem-
branes, or faulty head presentations, and also repeated examina-
tions, would assist infection before delivery. Inoculation may also
occur a few days after birth by pus conveyed by the fingers of the
mother or nurse, or by towels, etc., used for washing the child's face.

The more severe cases of blennorrhoea neonatorum are caused
by a vaginal discharge, which is almost always gonorrhoeal, and
Neisser's gonococcus, which is the exciting agent, can be found in
the discharge from the vagina and in the secretion from the eye.
It may be found in the epithelial cells, or in the pus cells, or free.
Mild catarrhal conjunctivitis also occurs in newborn infants, and in

CHAP. III.] THE CONJUNCTIVA. 59

these cases the ordinary microbes associated with that condition are
present, and occasionally the bacterium coli ; but in rare cases even
the gonococcus may produce a mild reaction, probably owing to
attenuation of the virus by dilution or drying. It should also be
noted that a typically purulent ophthalmia has, in exceptional
cases, been observed in infants (Morax) without the presence of
any micro-organisms, but then it usually takes a benign course.

If the infection take place during or immediately after birth,
the disease appears most commonly on the third day, but it may
appear at any time from the second to the sixth day, according to
the virulence of the secretion. If the inflammation come on later
than the sixth day, it may be concluded that the infection was
produced secondarily by the vaginal discharge being introduced
into the eye by the fingers of the mother or nurse, etc.

While purulent ophthalmia in adults is usually gonorrhoeal and
due to the gonococcus, it may exceptionally be the result of in-
fection by the Koch-Weeks bacillus ; the cases due to this bacillus,
however, are not so serious as those caused by the gonococcus.

In newborn infants both eyes are commonly affected. The
reverse is the case in adults, in whom also the disease is more severe.

Symptoms and Progress. — In mild cases the bulbar conjunctiva
may be but little, or not at all, affected, the palpebral conjunctiva
alone becoming velvety and discharging a small amount of pus,
while there may be no swelling or oedema of the eyelids.

In severe cases of blennorrhoea of the conjunctiva there is,
soon after the onset, serous infiltration of the palpebral mucous
membrane — which consequently becomes tense and shiny — marked
chemosis of the bulbar conjunctiva, serous discharge, dusky red-
ness, and swelling of the eyelids — which makes it difficult to evert
them — pain in the eyelids, often of a shooting kind, burning sensa-
tions in the eye, and photophobia. This first stage, or period of
infiltration, lasts from forty-eight hours to four or five days. The
preauricular lymphatic glands may be swollen and tender, and a
rise of temperature may occur.

Then begins the second or furulent stage, in which, owing to
swelling of the papillae, the palpebral conjunctiva becomes less
shiny and more velvety ; while the discharge alters from serous
to the characteristic purulent form, the chemosis, however, remaining
unaltered, or becoming more firm and fleshy. The swelling of the

60 DISEASES OF THE EYE. [chap. hi.

lids continues, the upper lid often becoming pendulous and hang-
ing down over the under lid ; while, at the same time, it becomes
less tense and more easily everted. Gradually the chemosis and
swelling of the conjunctiva and eyelids subside, and the discharge
lessens, the mucous membrane finally being left in a normal state,
unless in a small percentage of cases in which chronic blennorrhoea
remains. A moderately severe attack of conjunctival blennorrhoea
lasts from four to six weeks. A delicate scarring of the conjunctiva
in the fornices may be sometimes left after the attack.

Complications with corneal affections form the greatest source of
danger in this affection. They are found chiefly in four different
forms. (1) Small epithelial losses of substance which are apt to go
on to form deep perforating purulent ulcers. (2) The whole cornea
becomes opaque (diffusely infiltrated), and greyish purulent in-
filtrations may form towards its centre. (3) An infiltration may form
at the margin of the cornea, and give rise to a marginal ring ulcer,
and, later on, to sloughing of the whole cornea. (4) A clean-cut ulcer
may also form at the margin of the cornea. These ulcers are par-
ticularly apt to occur where there is much chemosis, which overlaps
the margin of the cornea ; and, being hidden in this way, they are
easily overlooked. The chemosis should be pushed aside with a
probe, and these peculiar ulcers looked for. They are very liable
to perforate.

All the foregoing forms of corneal complication occur both in
adults and infants, and the earlier they occur the more likely are they
to result in perforation and permanent opacities.

It is believed by some that corneal complications are due to
secondary infection with other micro-organisms.

The severer the case, especially the more the bulbar conjunctiva
is involved in the process, the more likely is it that corneal com-
plications will arise. Severe chemosis is less common in the blennor-
rhoea of the newborn than in gonorrhoeal ophthalmia, and this may
be the reason for the fact that the latter is much the more
dangerous affection of the two.

The Prophylaxis of purulent ophthalmia is a matter of the first
importance. It should form part of the routine of lying-in practice.
Careful disinfection of the vagina before and during birth, and
the most minute care in cleansing the face and eyes of the infant
immediately after birth with a non-irritating disinfectant {e.g. a

CHAP. ITT.] THE CONJUNCTIVA. 01

solution of corrosive sublimate 1 iu 5000), are to be recommended.
Crede's method is as follows : — When the child is in the bath, the
eyes are carefully washed with water from a separate vessel, the
lids being scrupulously freed, by means of absorbent wool, of all
blood, slime, or smeary substance ; and then, before the child is
dressed, a few drops of a 2 per cent, solution of nitrate of silver are
instilled into the eye.^ The conjunctival irritation which some-
times follows is unimportant as compared with the immense
advantages which result from this procedure. By its aid Crede
reduced the percentage of his cases of ophthalmia neonatorum from
8 or 9 per cent, to 0*5 per cent. Very good results have also been
obtained with 5 per cent, sophol.

In all cases of gonorrhoea it is the duty of the surgeon to explain
to his patients the danger of carrying any of the urethral discharge
to their eyes ; and to charge them to exercise punctilious cleanli-
ness as regards their hands and finger-nails, and care in the use
of towels, handkerchiefs, etc.

In respect of Local Treatment when the disease has become
established : — In the very commencement of the affection the only
local applications admissible are antiseptic lotions (Permanganate
of Potash Solution, 1 in 10,000 ; Sublimate, 1 in 5000) and iced
compresses, or Leiter's tubes. With the former the conjunctival
sac should be freely washed out or irrigated. Syringing is dangerous
both for patient and for operator, for in syringing out the conjunc-
tival sac the corneal epithelium may be injured and the cornea may
become infected ; and, as regards the operator, he is in danger of
discharge spurting into his eyes. The iced compresses, or Leiter's
tubes, should be kept to the eye for an hour at a time, with a pause
of an hour, and so on, or even continuously. Cold inhibits the
growth of the gonococcus. In this and in the next stage the chemosis,
if severe, should be freely, and daily, incised with scissors. If
the swelling of the lids be great, the external canthus should be
divided wdth a scalpel from without, leaving the conjunctiva un-
injured, in order to reduce the tension of the eyelids on the globe,
and, by bleeding from the small vessels, to deplete the conjunctiva.
Depletion alone can be obtained by leeching at the external canthus,
and in many cases is of great benefit at the very commencement.

^ The general opinion now is that a 1 per cent, solution is just as
efficient and less irritating.

62 DISEASES OF THE EYE. [chap. hi.

If in iidults the cliemosis, palpebral swelling, and rapidity of the
onset indicate that the inflammation is severe, it is well to place
the patient quickly under the influence of mercury by means of
inunctions or small doses of calomel, as by so doing the cliemosis
is often rapidly brought down, and one source of danger to the cornea
is removed.

In the second stage {i.e. when the conjunctiva has become velvety
and the discharge purulent) caustic applications are the most trust-
worthy, and in this respect iodoform and other lauded means
cannot compete with them. The surgeon should apply a solution of
nitrate of silver of 10 to 20 grains in §j of water, to the conjunctiva
of the everted lids ; or the solid mitigated nitrate of silver (one
part nitrate of silver, two parts nitrate of potash) may be used, the
first application being lightly made in order to test its effect, while
careful neutralisation with salt water and subsequent washing with
fresh water are most important. Iced compresses may be used
to relieve the subsequent pain. An interval of twenty-four hours
should elapse before the application is renewed. No remedy is of
greater value in purulent ophthalmia than the above mentioned
mitigated lapis, wdien the proper indications for its use are present,
and when it is applied with care and intelligence. Betw^een the
caustic applications, the pus should be frequently washed away from
the eyelids, and from between the eyelids, with a -i per cent,
solution of boric acid, or, better still, the conjunctiva should be
douched with a solution of permanganate of potash (1 in 5000) or
with a solution of corrosive sublimate of the same strength, and
boric acid ointment should be smeared along the palpebral margins,
to prevent them from adhering, and thus retaining the pus.

No corneal complication contra-indicates the active treatment
of the conjunctiva by the method just described. Iodoform, finely
pulverised, has been much praised as a local application in the
second stage of acute blennorrhoea of the conjunctiva. It is to be
dusted freely on the conjunctiva once or twice a day. For our part
we should trust to it alone in mild cases only. It can, however,
be employed with advantage in combination with the above treat-
ment.

AVhen but one eye is aflected, it is generally considered neces-
sary to protect its fellow from infection by means of a hermetic
dressing. This may be made by applying to the sound eye a piece

CHAP. III.] THE CONJUNCTIVA. 03

of lint covered with boracic acicT ointment, and over this a pad of
borated cotton-wool. Across this, from forehead to cheek and
from nose to temporal region, are laid strips of lint soaked in
collodion in layers over each other ; or a piece of tissue guttapercha
may take the place of the lint and collodion, its margins being
fastened to the skin by collodion. The shields invented by Maurel
and by BuUer are serviceable for this purpose. Yet with careful
instructions given to the patient, and average intelligence on his
part, protection of the sound eye is not necessary. In private cases
we do not close the second eye, and have never had ill effects in
consequence. Any sign of congestion was met by the application
of a 2 per cent, solution of nitrate of silver, and it always proved
sufficient to check the development of the disease, as it does in
Crede's method of prophylaxis.

Patients should be advised to sleep on the side of the affected
eye, in order to prevent the discharge from trickling on to the other
side of the face.

Treatment of Corneal Complications. — The involvement of the
cornea does not contra- indicate the use of the methods already
described, but rather demands their vigorous application. In
addition, atropine will relieve pain and diminish the tendency to
iritis. Eserine is sometimes employed with the object of reducing
the tension, and so improving the nutrition of the cornea by facili-
tating the lymph circulation, and also on account of its antiseptic
properties. But, as its action on the normal tension is practically
nil, and its antiseptic properties are very slight, it is better to reserve
it for cases of marginal ulcer with prolapse, or danger of prolapse,
of the iris, since by the contraction of the sphincter the iris is drawn
away from the periphery. Greater care is now required in everting
the lids, lest pressure on the globe should cause rupture of the ulcer ;
and it must be remembered that when a case of acute blennorrhoea
first presents itself, the surgeon, not knowing the condition of the
cornea, must use the utmost caution in making his examination,
and yet must never fail to get a view of the cornea for the purposes
both of prognosis and of treatment. At each visit the cornea must
be examined, and it may be found that, as the conjunctival process
subsides, any existing corneal affection also improves. But even
though the conjunctiva be improving, the corneal process may
progress, until, finally, the ulcer perforates.

CA DISEASES OF THE EYE. [cHAr. in.

Should a corneal ulcer become deep, aud seem to threaten to
perforate, paracentesis of the floor of the ulcer must be resorted to
without delay. Through the small linear opening thus made no
prolapse of the iris, or else a relatively small one, takes place.
The reduction of the intra-ocular tension after the paracentesis
promotes healing of the ulcer. It is often desirable to evacuate the
aqueous humour, by opening the little incision in the floor of the
ulcer with a blunt probe, on each of the two days after the operation.

If an ulcer perforate spontaneously, the aqueous humour is
evacuated, and, unless the ulcer be opposite the pupil and at the
same time small in size, the iris must come to be applied to the
loss of substance. Should the latter be very small, the iris will
simply be stretched over it and pass but little into its lumen, and
when healing takes place will be caught in the cicatrix, which is but
slightly, or not at all, raised over the surface of the cornea, and
the resulting condition is called Anterior Synechia.

If the perforation be larger, a true prolapse of a portion of the
iris into the lumen of the ulcer takes place. This prolapse may
either act as a plug, filling up the loss of substance and keeping
back the contents of the globe, but not protruding over the level
of the cornea, or it may bulge out over the corneal surface as a black
globular swelling, and may then play the part of a distensor of the
opening, causing fresh infiltration of its margins. In either case
cicatrisation will eventually occur ; and if the scar be fairly flat,
it is called an Adherent Leucoma, but if it be bulged out, the term
Partial Staphyloma of the Cornea is used.

If the perforation be very large, involving the greater part
of the cornea, with prolapse of the whole iris and closure of the
pupil by exudation, the result is a Total Staphyloma of the Cornea.
The lens may lie in this staphyloma, or it may retain its normal
position, but become shrunken.

The question of the treatment of a recent prolapse of the iris
in cases of blennorrhoeic conjunctivitis is an important one. It
has been, and is still largely, the practice to abscise small iris-pro-
trusions down to the level of the cornea, or if large to cut a small
bit off their summits, with the object of obtaining flat cicatrices.
But in cases of blennorrhoea this proceeding opens a way for purulent
infection of the deep parts of the eye, and serious consequences
may result. It is better to confine interference with the iris in

CHAP. III."! THE CONJUNCTIVA,

these eyes to incision of the prolapse, when it seems to be acting
as a distensor of the opening, causing fresh infiltration of the cornea ;
or merely to instil eserine, which has a marked effect in diminishing
the size of the protrusion.

The margins of the eyelids may be gummed together by sero-
purulent secretion, while the eyelids are bulged out by the pent-up
fluid behind them ; the attempt to open the eye should then be
very cautiously made, lest some of the retained pus spurt into the
surgeon's eye. The surgeon should also be most careful to wash
thoroughly and disinfect his hands and nails at the conclusion of
his visit.

In cases of blennorrhoea neonatorum, when the ulcer has been
small, on perforation taking place, the lens, or rather the anterior
capsule, comes to be applied to the posterior aspect of the cornea.
The pupillary area is soon filled with fibrinous secretion. The open*
ing in the cornea ultimately becoming closed, the iris and lens are
pushed back into their places by the aqueous humour which has
again collected. Adherent to the anterior capsule where it Jay
against the cornea is a deposit -of fibrine, which gradually becomes
absorbed by the aqueous humour. In the meantimxe changes have
been produced by this exudation on the corresponding intracapsular
cells, which result in a small, permanent, central opacity at that
place, where there is also a sHght elevation of pyramidal shape over
the level of the capsular surface. This condition is called central
capsular cataract, or pyramidal cataract, and rarely results from
cornea] perforation in adults.

In cases of blennorrhoea neonatorum an inflammatory swelling
of the joints, so-called gonorrhoeal arthritis, is very occasionally
seen. The gonococcus has been found in the fluid removed from
the joints in some cases, while in others only the usual pyogenic
cocci were present. Even more rarely do peri- and endo-carditis,
pleuritis, and meningitis occur.

Metastatic Gonorrhoeal Ophthalmia is sometimes met with in adolescents
or adults, as an accompaniment of gonorrhceal artliritis. It is apt to occur
with cessation of the urethral discharge. Both eyes are nearly always
affected. The disease presents the appearance of a moderate catarrhal
ophthalmia chiefly affecting the bulbar conjunctiva, with scanty secretion,
but it is occasionally complicated with keratitis, iritis, or scleritis. It
shows a great tendency to recur with a relapse of the " rheumatism." On
the other hand, the conjunctival affection may be the only sign of a

OG DISEASES OF THE EYE. [chap. hi.

systemic affection. Gonococci have sometimes been found in the secre-
tion from the conjunctiva. Tliree views are held with regard to causa-
tion : (a) that the gonococci are carried to the eye through the circulation ;
(6) that it is due to a gonotoxin ; or (c) that the gonococci prepare the
soil for a mixed infection. It is easily cured by local treatment.

Quite recently good results have been obtained, in all forms of gonor-
rhoeal infection, with an atoxic gonococcal vaccine prepared in the Pasteur
Institute of Tunis according to a formula of Nicolle and Blaizot.

* Membranous Conjunctivitis. — This disease is characterised
by the existence of a fibrinous exudation, either on the surface or
in the substance of the conjunctiva, in addition to the other symp-
toms of inflammation. It was formerly believed, on purely clinical
grounds, that the mild form of the disease, known as croupous
conjunctivitis, was totally different in nature from the severe or
diphtheritic form, and later on this view seemed to be borne out
by the discovery of the Klebs-Loeffler bacillus in the diphtheritic
cases ; but further experience of the bacteriology of membranous
conjunctivitis has altered this view. Not only is the diphtheria
bacillus found in mild croupous cases, but any of the micro-organisms
which commonly cause conjunctivitis, may give rise to fibrinous
exudations and the formation of membranes. The same condition
in varying degrees of severity can be produced by chemical irritants,
such as lime, ammonia, etc., and also by jequirity. Lastly, the
diphtheria bacillus may, in rare cases, lead to a simple catarrhal
inflammation without the production of a false membrane. The
presence of a membrane therefore is only a symptom, and is not
necessarily pathognomonic, although it is very suggestive of the
Klebs-Loeffler bacillus as the cause.

In severe cases strepto- and staphylo-cocci are generally associ-
ated with the diphtheria bacillus, and indeed the streptococcus,
staphylococcus, and pneumococcus acting alone can occasionally
cause severe membranous inflammation of the conjunctiva.

There is reason to believe that the diphtheria bacillus can only
act on the conjunctiva when the epithelium has been injured,
say by a slight, even imperceptible trauma, or by a previous
inflammation.

The Xerosis bacillus must not be mistaken for the Klebs-Loeffler
bacillus ; the only reliable method of distinguishing one from the
other is by inoculation in animals.

Microscopically the false membrane consists of a fibrinous net-

CHAP. III.] THE CONJUNCTIVA. 67

work contaiiiiiig leucocytes, a few epithelial cells, and often micro-
organisms. In the so-called croupous cases the underlying epithelium
may or may not be adherent to the false membrane, but even in
the latter event, although the epithelium separates along with the
membrane, the surface left is smooth and becomes covered by
regenerated epithelium, so that no trace of scarring occurs.

On the other hand, in the severe or diphtheritic cases the sub-
mucous tissue is involved in the exudation, the vessels become
compressed by it, and this leads to necrosis. When the dead tissue
has been cast off a granulating surface is exposed which heals by
cicatrisation. These are true granulations in the surgical sense,
and are therefore quite different from the " granulations " of
trachoma.

Etiology. — Membranous conjunctivitis in all degrees of severity
is met with for the most part in children, more especially in
those under four years of age. The Streptococcal form often
follows an attack of measles or scarlatina, and is frequently accom-
panied by eczema or by ulcers of the skin in the neighbourhood of
the eyes.

One or both eyes may be attacked. It is an acute disease, which
occurs sporadically or in epidemics, but a few chronic cases have
been seen to last for many months.

Clinically, the mild or croupous form of the disease can readily
be distinguished from the severe or diphtheritic ; hence they will
be described separately, with the understanding that the real
nature of each case can only be decided by careful bacteriological
examination.

Croupous Conjunctivitis. — The symptoms are those of catarrhal
conjunctivitis, to which in a few days is added the appearance of a
greyish pellicle on the palpebral conjunctiva, sometimes also on the
retro-tarsal folds, but rarely on the bulbar conjunctiva. The false
membrane can be peeled off, leaving a mucous surface underneath
which may or may not bleed. The lids, which may be red and
swollen, are always soft and easily everted. After a week or so the
second or secreting stage sets in, with the appearance of a discharge,
and the false membrane becomes separated, leaving a healthy
mucous surface which gradually returns to its normal condition,
without any trace of scarring. Observations with reference to
corneal complications vary, some observers never having seen them,

68 DISEASES OF THE EYE. [chap. hi.

while others have noted them in 40 per cent, of their cases. Con-
stitutional symptoms are much less frequent than in the severe or
diphtheritic variety of this affection.

Treatment. — In the first stage iced compresses or Leiter's tubes
applied to the lids, with antiseptic cleansing of the conjunctival
sac. No caustic should be used in this stage, as it is apt to produce
corneal changes. Sulphate of quinine insufflated, or in 2 per cent,
solution, is praised by some surgeons as a useful application at this
period. In the secreting stage nitrate of silver applications should
be made in the usual way.

When the Klebs-Loeffler bacillus is the active agent antitoxin
should be used. Simple instillations into the conjunctival sac, with
which we have obtained a good result, may suffice in these mild
cases. (See Treatment of Diphtheritic Conjunctivitis.)

Diphtheritic Conjunctivitis. — There is no more serious ocular
disease than this, for it may destroy the eye in twenty-four hours ;
while in severe cases treatment is almost powerless. Fortunately
it is exceedingly rare in these countries.

The subjective symptoms of its initial stage are similar to those
of blennorrhoeic conjunctivitis, but severer, especially in the matter
of pain. The objective symptoms differ from those of blen-
norrhcea, in that the lids are excessively stiff, owing to plastic in-
filtration of the sub-epithelial and deeper layers of the conjunctiva,
while the surface of the mucous membrane is smooth, and of a grey-
ish or pale buff colour. If an attempt be made to peel off some of
the superficial exudation the surface underneath will be found
of the same grey colour, not red and vascular, as in croupous con-
junctivitis. Ulcers of the skin covered with a greyish membrane
are often present on the eyelids and cheek, or round the nostrils
or lips, and the preauricular glands are enlarged. This stage of
infiltration lasts from six to ten days, and constitutes the period of
greatest peril to the eye ; for while it lasts the nutrition of the
cornea must suffer, and sloughing of that organ is extremely apt
to take place. Towards the close of the first stage the fibrinous
infiltration is eliminated from the eyelids, and the conjunctiva
gradually assumes a red and succulent appearance, and at the
same time a purulent discharge is established. This constitutes
the second or Uennorrhceic stage. A third stage is formed by cica-
tricial alterations in the mucous membrane, which often lead to

CHAP. TIL] THE CONJUNCTIVA. 69

symblepharon, or to xerophthalmos ; so that, even if the eye escape
corneal danoers in the first and second stages, others almost as
serious may await it in the final stage.

Corneal complications are most likely to occur in the first stage,
and are then also most likely to prove destructive to the eye. The
earlier they appear the more dangerous are they. If the blennor-
rhoeic stage come on before corneal complications appear, or even
before an ulcer contracted in the first stage has advanced far, thev
are more easily controlled.

In the third stage corneal affections, if they occur, are of a chronic
nature and are generally accompanied by vascularisation.

This disease is nearly always combined with constitutional
symptoms, such as fever, malnutrition, albuminuria, and is some-
times fatal ; but, strange to say, it is very rarely followed by para-
lysis, even of accommodation. It has seldom been observed to
follow diphtheria of the throat, although the opposite sequence is
not uncommon.

Treatment. — If the disease be due to the Klebs-Loeffler bacillus,
antitoxin serum is the sovereign remedy, and as the identifica-
tion of the diphtheria bacillus takes time, any presumption of
its presence should be acted upon without delay. The injections
may be given under the skin of the eyelids, and instillations into
the conjunctival sac may be made as well. In streptococcal cases
anti-streptococcus serum may be used, but it does not act so well
as the diphtheria antitoxin. Precautions should of course be
taken to avoid the transference of the disease to other persons. In
cases caused by the pneumococcus, Romer's pneumococcus serum
may be used. These remarks also apply to croupous con-
junctivitis.

Local treatment in the first stage should consist in cold applica-
tions and antiseptics ; later on, warm fomentations, especially if
the patient finds them more agreeable, can with advantage be
substituted for the cold. In the secreting stage the same lines of
treatment should be followed as in catarrhal conjunctivitis, except
that greater precaution should be taken in using nitrate of silver ;
the greater the discharge the more freely it may be applied. Corneal
ulcers must be dealt with, whenever they arise, in the same way as
though the case were one of blennorrhoeic conjunctivitis. When
the purulent discharge ceases, solutions containing soda or glycerine

70 DISEASES OF THE EYE. [chap. hi.

may be prescribed as lotions for the conjunctiva, to relieve the
xerophthalmos.

Hay Fever. — This is not uncommon among the better classes in
these countries, although it is rarely seen in our hospital patients. The
symptoms, in those liable to it, appear in the early summer each year,
and disappear again in the course of six weeks or two months. They
consist in catarrh of the nostrils, accompanied by great itching of them
and frequent sneezing ; while the conjunctiva, especially in the lower
fornix, becomes somewhat hypersemic, and there is lacrimation. There
is excessive itching of the eyes, which renders the patient most wretched,
and compels him to rub his eyes violently. There is photophobia. The
respiratory tract may become involved, with some bronchitis and asthma,
and general malaise and elevation of temperature are present. Some-
times the eyes alone are affected. There is no tendency to corneal com-
plications. Dviring an attack the eosinophile cells in the conjunctival
sac are increased in number as in Spring Catarrh.

Treatment is of no avail in preventing the annual recurrence of the
affection, nor is it of much use in alleviating the attack. No strong local
application should be employed. Weak collyria, or ointments, of sulphate
of zinc, or copper, boric acid, or sublimate, etc., may be tried. Adrenaline,
cocaine, or holocaine eye drops (2 per cent.) afford the best relief. Dark
glasses should be worn.

Dunbar's hay fever serum, called pollantine, has been used with benefit
in some cases.

Trachoma (rpaxts, rough), Granular Conjunctivitis, or Granu-
lar Ophthalmia (also called Egyptian Ophthalmia and Military
Ophthalmia). — In this disease, in addition to the usual appearances
of simple conjunctivitis, there are developed translucent greyish
or pinkish-grey bodies about the size of the head of a pin or larger,
situated in, and close to the fornix conjunctivae, chiefly of the upper
lid. They also occur on the tarsus, in the lower fornix, and some-
times on the plica semilunaris, but are very rarely met with on the
bulbar conjunctiva. The tarsal growths are smaller, flatter, and
yellower in colour than those seen in the fornix. These bodies
are the trachoma bodies or granulations, or " sago grains," they
somewhat resemble the follicles of follicular conjunctivitis, except
that they are paler, more irregular in size and less apt to occur in
rows.

Microscopically they exhibit the structure of hjmplioid follicles,
and consist of an outer zone of small lymphocytes and a central
mass of larger endothelioid cells, amongst which some very large
cells are found with irregular processes and cell-inclusions. These

CHAP. III.] THE CONJUNCTIVA. 71

are the so-called " trachoma cells " or " corpuscle cells " ; they
are supposed to be phagocytes or enlarged connective tissue cells,
and have even erroneously been taken for protozoa, but since they
exist in normal lymph follicles in other places, they are not in any
sense specific. The cellular elements of the follicle lie in the meshes
of a delicate reticulum, the follicle itself being surrounded by a
vascular network and a more or less defined capsule.

The unevenness of the conjunctival surface is still further in-
creased by a luxuriant formation of fapillce due to the folding of
the inflamed and hypertrophied mucous membrane, which also
leads to the development of microscopic glands and later on of
small cysts. The latter are met with in the furrows between the
papillae, or they may be produced by solid downgrowths of epithe-
lium, which become softened in the centre. The follicles ultimately
become absorbed, or soften, and extrude their contents on the
surface. In any case their disappearance is followed by the
development of fibrous cicatricial tissue, from the shrinking of
which various complications, which will be mentioned later on,
ensue. The tarsus may be involved in the inflammation, and in
many cases a vascular, richly cellular layer called pannus forms
in the cornea between the epithelium and Bowman's membrane.

Etiology and Cause. — There can be no doubt but that this disease
is contagious, and that it is the result of a specific cause, the nature
of which is still unknown. Peculiar
cell-inclusions have been found in
the epithelial cells, in smear pre-
parations of the secretion or of the
scrapings taken from recent untreated ^
cases. The appearance which they

present varies in different stages.

t,. oo /f • • 1 J • Fig. 38.— Epithelial cell

bis. 38 (from an ormmal drawmg, , ^, • -• t ^ ^^

^ , , from the conjunctiva ot a case

for which we are indebted to the of trachoma.

kindness of Professor Greeff , one of («) ceii inclusions, forming a duster

the discoverers of these Cell-inclu- in the protoplasm of the cell, dose to

the nudeus (6), (r) isolated granules.

sions) illustrates one of the most

characteristic stages. The nature of these fine granules has not,
however, been ascertained, and their causative relation to granu-
lar ophthalmia has not been established. Unfortunately it has
not yet been possible to isolate or cultivate them, and hence no

72 DISEASES OF THE EYE. [chap. hi.

pure cultures have been obtained with which to perform experi-
ments. More recently, similar cell inclusions have been found in
non-gonococcal forms of ophthalmia neonatorum (and even in the
normal conjunctiva), and for this and other reasons the theory has
been advanced that these minute bodies are an involution form of
the gonococcus. They have also been found in cases of gonorrhoea,
both in males and females, but it is still uncertain whether any real
relation exists between this disease and granular ophthalmia. By
some these cell-inclusions are held to be merely products of nuclear
degeneration.

The histological changes are not peculiar to this disease alone
— the papillary hypertrophy is well seen in chronic blennorrhoea,
for instance — and even lymph follicles occur from other causes ;
for 'example, from atropine irritation and in tuberculosis. In-
fection occurs only by transference of the secretion from one eye
to the other by means of fingers, towels, handkerchiefs, etc. Hence
slovenly personal habits, overcrowding of dwellings, schools, or
barracks help the disease to spread from one individual to another
when it once gains a foothold in a country. A great deal, however,
remains to be learned as to the manner in which contagion takes
place. The infectiousness of chronic cases cannot be very great, for
nurses and doctors rarely, if ever, become infected by their patients.
Neither do we see trachoma patients infecting surgeons, nurses, or
other patients in the hospitals in Ireland, where the disease is so
prevalent. Were the infectiousness of the disease very great, even
the precautions taken in a well-ordered hospital against contagion
would hardly be sufficient to prevent such an occurrence occasionally.
Moreover, inoculation experiments do not always succeed.

Amongst the better classes, both here and elsewhere, the disease
is very uncommon. Even the poor in high, dry, mountainous
countries are almost free from it, so that, probably, the atmospheric
conditions play some part in the etiology.

Some hold that the affection is dependent on constitutional
disease, such as scrofula, tuberculosis, syphilis, etc. ; but we cannot
endorse this view. No doubt many of these patients are anaemic
and out of health, but this is due to the moping habits they contract,
and the little open-air exercise they take in consequence of their
semi-blindness.

The effect of race as a predisposing cause is doubtful. Jews

CHAP. III.] ^ THE CONJUNCTIVA. 73

are said to be peculiarly liable to the disease, but it must be re-
marked that in them as in others it only occurs amongst the very
poor.

Trachoma generally attacks both eyes and is an extremely
chronic affection. An acute form is described, which, however, must
be very rare, as it is practically non-existent in Ireland, although
the chronic variety of the disease is so common here.

Acute Trachoma, or Acute Granular Ophthalmia. — The symptoms
are those of a more or less acute purulent ophthalmia, associated
with the characteristic appearances of trachoma. The acute symp-
toms are really due to an additional infection by the gonococcus or
Koch- Weeks bacillus.

Treatment. — In the early stage the treatment is the same as for
acute blennorrhoea, while at a later period the same methods are
adopted as in chronic trachoma.

Chronic Trachoma, or Chronic Granular Ophthalmia. — In the
early stage, which may pass unnoticed, this disease is often un-
accompanied by inflammation, and is then unattended by any dis-
tressing symptoms, except that the eye may be more easily irritated
by exposure, or more readily wearied by reading or near work. At
this period the conjunctiva will be found free from injection except
perhaps at the inner and outer corners of the palpebral portion of the
upper lid, where there may be a slight roughness or some small
follicles. But later on greyish-white semi-transparent trachoma
bodies, of the size of a rape-seed and less, may be found in the upper
fornix, sometimes only by careful examination, or again, they may
be seen disseminated over the conjunctival surface of the upper lid,
and protruding from it. Gradually these trachoma bodies or granu-
lations give rise to a more or less active vascular reaction, attended
with swelling of the papillae and purulent discharge — in short, slight
blennorrhoea. This is the stage of progression (Fig. 39). The
patients then begin to be more inconvenienced, owing to the discharge
which obscures their vision, to sensations of weight in the lids and of
foreign bodies in the eye, and to partial ptosis, which gives them a
sleepy look. This is generally the earliest stage at which we see the
disease. The enlarged papillae often grow to a great size, completely
hiding the granulations, constituting what is known as the " papillary
form " of the disease. In this stage the granulations may become
absorbed, and the disease undergo cure ; but more commonly it

74 DISEASES OF THE EYE. [chap. hi.

makes further progress. Fresh granulations appear, while the
old ones increase in size and undergo a peculiar gelatinous change.
They then often become confluent, leaving only here and there an
island of vascular mucous membrane. Sometimes the trachoma
bodies are very small, and present the appearances of minute yellowish
dots, and in this form they are not always easily found.

Gradually the follicles become absorbed, or more rarely their
contents are expelled, and the connective tissue proliferates so as
to cause more or less extensive scarring of the conjunctiva. This
constitutes the cicatricial stage of the disease. The scarring frequently

/ /. .A

Fig. 39. — Granular ophthalmia ; Fig. 40. — Granular ophthalmia ;

progressive stage. cicatricial stage, with pannus and

trichiasis.

presents a reticulated appearance, and in many cases assumes the
form of a white line situated in the subtarsal sulcus. Fig. 40.

The tarsus may undergo fatty or hyaline degeneration or be-
come hypertrophied, while the diseased conjunctiva on the inner
surface of the lid causes curving of the tarsus with entropion and
distortion of the bulbs of the eyelashes, followed by irregular grou'th
of the latter, with resulting trichiasis and distichiasis. These
changes are represented in Fig. 41. The bulbar conjunctiva may
become atrophied, cease to secrete, and become dried, giving rise
to xerosis. In consequence also of the shrinking of the conjunctiva,
the fornices may become partially or wholly obliterated, thus causing
symblepharon (adhesion of the eyelids to the eyeball).

The great danger of granular ophthalmia lies in the complications
which may attend it, or which follow in its wake ; the former are
pannus, ulcers of the cornea, and severe purulent conjunctivitis,
while the latter are the distortions of the lids and eyelashes just
referred to.

CHAP, III.

THE CONJUNCTIVA.

Fig. 41. {Scemisch.)
Section of a trachomatous eyelid.

a. Muscle :, h h, Tarsus having undergone
fatty degeneration ; c, Atrophied Meibomian
Grland ; d d, Hypertrophied Papilla ; e, Cica-
tricial Tissue in the conjunctiva ; /, Tarsus.

Pannus {Lat. a cloth rag)
presents the appearance (Fig. 40)
of a superficial vascularisation
of the cornea, with more or less
diffuse opacity, and often small
infiltrations. The new vessels
can be seen to grow in from the
conjunctiva. It invariably com-
mences in the upper portion of
the cornea, extending generally
over the upper half, and fre-
quently remains confined to this
region. But in many cases, at a
later stage, it extends over the
whole surface of the cornea ;
this latter occurrence often takes
place almost suddenly, and the
vascularisation and opacity
sometimes become so intense as to present quite a fleshy appear-
ance, completely hiding the corresponding part of the iris from
view. Histologically, pannus consists of a new growth, which
is extremely rich in cells, and which closely resembles the con-
junctiva when occupied with confluent granulations. It is in
fact a vascular granulation tissue, which grows in from the
limbus, and is situated between the corneal epithelium and Bow-
man's layer. After a length of time Bowman's layer becomes
destroyed in places, and then the cellular infiltration gains access
to the true cornea, and gives rise to permanent changes in its
transparency and curvature. In some bad cases of old-standing
pannus the latter undergoes a connective-tissue change. It then
becomes smooth on the surface, and the vessels almost disappear,
so that the cornea is covered with a thin layer of connective
tissue, which obstructs the passage of light and is not capable
of cure. Small ulcers, and sometimes white deposits, are liable
to form at the lower edge of the pannus near the centre of
the cornea. These deposits are superficial, and can be easily
scraped off.

Another result of pannus, sometimes seen, is a bulging or staphy-
lomatous condition of the cornea, the tissues of which have become

76 DISEASES OF THE EYE. [chap. m.

so altered and weakened that they give way before the normal

intra-ocular tension.

A pannns in which as yet there is no connective-tissue alteration,
and where there is no staphylomatous bulging, is capable of under-
going cure without leaving any opacity behind, except that which
may be due to ulcers that have been present.

Pannus is generally accompanied by photophobia and ciliary
neuralgia. It may come on at any stage of the disease, and causes
defective vision, in proportion to the degree and extent of the
opacity. Severe pannus is liable to induce iritis.

It was for a long time held that pannus was due to mechanical
irritation, caused by the rough palpebral conjunctiva ; but even
severe pannus is often seen with a comparatively smooth conjunctiva,
while with a truly rough conjunctiva the cornea is frequently perfectly
clear. There can now be little doubt that pannus is analogous to
the granular disease in the conjunctiva. It is, in fact, the same
disease modified by reason of the different tissue in which it is
situated, this different tissue being itself a modification of the con-
junctiva ; and microscopic examination of the bulbar conjunctiva
shows that it is infiltrated though apparently unaffected on clinical
inspection. So that pannus is a direct extension of the disease to
the cornea. Visible follicles in the bulbar conjunctiva are extremely
rare ; we have however seen a neglected case in which the patient
refused all treatment, and not only were there follicles on the bulbar
conjunctiva, but also on the cornea.

Prognosis. — At any period prior to cicatrisation of the con-
junctiva an attack of purulent blennorrhoea is liable to come on.
If not too severe, this may result in a cure by absorption of the
trachoma bodies, and should not be checked. If, however, the
attack be very severe, the eye runs dangers similar to those of an
ordinary attack of purulent conjunctivitis. These dangers are less
the more complete and the more intense the pannus.

On the whole, if the disease come under care at an early period,
and if treatment be carried out strictly, vision will be retained in
a majority of cases, although a radical cure may be difficult or
impossible. Patients require to be under constant treatment for
long periods, and the very lengthened time, and steady continuous
treatment needed for a cure, are probably the main obstacles to
that cure. In most cases of chronic granular ophthalmia, attend-

OHAP. iii.l THE CONJUNCTIVA. 77

ance three times a week for a year will be required, to effect any-
thing that can be called a cure. The common experience is that
patients attend for some weeks, and then, being very considerably
relieved of their distressing symptoms, and finding their sight vastly
impi'oved, they cease attendance long before the disease has been
eliminated, to return after a brief interval with a condition of things
as bad as, if not worse than, before. It is therefore desirable at the
very outset of treatment to explain the tedious and dangerous
nature of the ailment to each patient.

Treatment. — The aim of this is to bring about the absorption
or disappearance of the trachoma bodies with the greatest possible
despatch, in order to prevent the destruction of the mucous mem-
brane, to which they tend.

The methods of treatment on which most reliance is placed,
either separately or in combination, are : — the application of caustics,
mechanical or operative procedures, and the use of jequirity. In
conjunction with these, cases attended by inflammatory symptoms
and discharge must be treated according to the general principles
indicated on p. 54, and antiseptic lotions or sterilised fluids should
be used to keep the conjunctiva free from discharge, and a simple
ointment should be applied to the eyelids at night. Complications
may require to be dealt with by special methods. Attention should
be paid to the general health of the patient, and to the hygienic
conditions under which he lives, and finally prophylactic measures
should be taken to prevent the spread of the disease to other members
of the household or community.

I. Caustics. — No caustic application should be made with the
object of directly destroying the trachoma bodies, for this can be
done only at the expense of the mucous membrane around them.
The most useful caustics are nitrate of silver and sulphate of copper.
For chronic cases, with but little swelling of the papillae (blen-
norrhoea), and with little or no cicatrisation, the best application
is the solid sulphate of copper lightly applied to the conjunctiva,
especially at the fornix ; but when there is considerable papillary
swelling or discharge, a 2 per cent, solution of nitrate of silver,
or a light application of mitigated silver nitrate, neutralised with salt
solution, is to be preferred, Should there be ulcers on the cornea, or
much inflammatory irritation of the eye, sulphate of copper should
not be applied to the conjunctiva. An interval of twenty-four

78 DISEASES OF THE EYE. [chap. in.

hours at least should be allowed to elapse between each application,
whether of sulphate of copper or nitrate of silver, and cold sponging
for fifteen minutes should be employed immediately after the
application. A change of treatment will be occasionally required,
even if the remedy first used answer well in the beginning, and one
or other of the following can be adopted. Pure liquefied carbolic
acid has been used with good result, but we have no experience of
it. It is applied w^ith a camel's-hair pencil, and the excess washed
off with plain water. Solution of sublimate, 1 in 1000, or even 1 in
500, may be applied with lint or cotton-wool to the everted con-
junctiva with some pressure and rubbing. Alum, in the solid form,
is also used in the same way, and in the same class of cases, as
sulphate of copper. Ointments of copper sulphate (J to 1 per cent.)
or copper citrate (10 per cent.) are sometimes employed, but they
are not so active as the crystal. Sulphate of zinc is indicated if,
as is sometimes the case, angular conjunctivitis be present as a
complication.

2. Mechanical and Operative treatment. — The best of these pro-
cedures are : expression, which aims at evacuating the granulations,
and excision of the fornix, by which those situated in that region
are removed en masse. Expression was formerly practised by the
late Sir William Wilde of Dublin, who squeezed out the granulations
between the thumb nails. The present-day proceeding is carried
out aseptically by means of Knapp's roller forceps, or better still

Fig. 42.

with Graddy's forceps (Fig. 42). Similar but smaller instruments
are also made for the purpose of reaching the inner and outer angles
of the lids, where it is difficult to apply the larger ones. The opera-
tion is very painful, and general anaesthesia may be necessary.
The retro-tarsal fold of the everted lower or upper lid is grasped as
far back as possible between the blades of the instrument, com-
pressed and drawn upon, and in this way the trachomatous tissue
is squeezed out with little or no laceration of the conjunctiva. The

CHAP. III.] THE CONJUNCTIVA. 79

instrument has to be re-inserted and a neighbouring part of the
conjunctiva treated in the same way, and so on, until the whole
conjunctiva of each affected eyelid has been operated on. The
four eyelids may be manipulated at one sitting, and the evacuation
should be as complete as possible. Particular care should be taken
to reach the part of the conjunctiva which is hidden under the
commissures. Some cases are immediately and permanently cured
by this operation ; while others, although greatly benefited, will
still require further routine treatment with local remedies. Ex-
pression is indicated only where trachomatous substance can be
pressed out. Our experience with this method leads us to regard
it as a very useful one for the acceleration of the cure of recent cases,
some of which we have seen to recover with scarcely any trace
of scarring. We often apply silver nitrate immediately after
expression.

Excision of the upper fornix of the conjunctiva also renders great
service. This method shortens the treatment of all forms of the
disease; the granulations in the palpebral conjunctiva, although
not directly included in the operation, disappear quickly, and
recurrences of the disease are rarer than by other methods of treat-
ment. The resulting linear cicatrix has no serious consequence,
and is as nothing when compared w4th the extensive cicatricial
degenerations of the whole mucous membrane which the operation
is calculated to prevent. In order to avoid cicatricial contraction
care should be taken, during the operation, that sufficient mucous
membrane be left to completely cover the globe when the patient
looks down. Supplemental treatment with the customary local
applications is employed until the cure is obtained. We find this
an exceedingly useful procedure in some cases. When the tarsus is
much thickened, partial or complete excision, including the con-
junctiva over it, should be performed.

Other mechanical methods are : scarification, scraping with a
sharp spoon, brushing the conjunctiva with a metallic or stiff tooth-
brush, followed by a rubbing with (1 in 500) solution of corrosive
sublimate, electro-cautery, and electrolysis.

3. Infusion of Jequirity {Abrus precatorius, Paternoster Bean)
is made by macerating 154 grains of the decorticised jequirity seeds
in 16 oz. of cold water (a 3 per cent, infusion) for twenty-four hours.
Twice a dav for three davs the lids are everted, and the infusion

80 DISEASES OF THE EYE. [chap. hi.

thoroughly rubbed into the conjunctiva with a bit of lint. The
result is a severe conjunctivitis with a somewhat croupous tendency
(even the cornea being often hidden by the false membrane), accom-
panied by great swelling of the eyelids, much pain, and considerable
constitutional disturbance, rapid pulse, and temperature of 100°,
or more. At first the pannus becomes more visible, but as the
inflammation subsides, it diminishes or even disappears, while com-
plete cure of the granular ophthalmia itself is rarer. Iced compresses
to the eyelids may be used during the inflammation. A fresh
infusion (not more than seven days old) must be employed in order
to secure the best reaction. We find the remedy harmless, if not
always successful ; but a good many cases are on record where
violent diphtheritic conjunctivitis, followed by blennorrhoea of the
conjunctiva, and by more or less extensive ulceration of the cornea,
and even complete loss of the eye, were produced. We have,
occasionally, seen small superficial ulcers form on the cornea without
further injury. The presence of a purulent discharge from the
conjunctiva is a contra-indication for this treatment, which is then
liable to increase the intensity of the blennorrhoea in a dangerous
degree. Cases where there is little or no papillary SAvelling, but
merely dry trachoma with pannus, are the most suitable for its use,
and we cannot recommend it too highly in these cases. Very rapid
and effective cures of the severest pannus sometimes follow the use
of this remedy in properly selected cases. But the presence of well-
marked pannus of the cornea without ulceration is the only thing
that can render the employment of jequirity justifiable, and in
addition to this, as stated, the conjunctiva should be free from
blennorrhoea.

The occurrence of acute dacryocystitis is said to form an un-
pleasant complication of the jequirity treatment, even in cases in
which the sac was previously quite normal ; but we have never
seen it to occur.

In our opinion the danger of jequirity ophthalmia can be mini-
mised considerably by taking care, when beginning the treatment,
to allow twenty-four hours to elapse before making a second appli-
cation. One can then gauge the degree of reaction, which is liable
to vary with different infusions or Avith the idiosyncrasy of the
patient. As a matter of fact, we have seen one patient who was
absolutely immune to jequirity.

CHAP. III.] THE CONJUNCTIVA. 81

Jequiritol, the active principle of jequirity, dissolved in glycerine
and standardised experimentally, is sometimes used instead of
jequirity. We have not found it as effective as jequirity, and it has
the great disadvantage in hospital work of being very much more
expensive.

After the subsidence of the jequirity inflammation some of the
local remedies, above referred to, should be regularly applied for
the purpose of completing the cure of the conjunctival condition.

4. Treatment of complications. — Where pannus is present, an
occasional drop of atropine should be instilled, in order to control
the tendency to iritis ; but pannus in itself requires no special treat-
ment unless it persists after the conjunctival disease has entered
the cicatricial stage, when, as stated above, jequirity is of service.

The operation of fefitomy may also be performed for pannus.
It consists in the excision of a portion of the conjunctiva, about
5 mm. broad, around the corneal margin. Destruction of the
vessels with the actual cautery we have also found to do good in the
treatment of pannus.

Ulcers of the cornea, if small, require no additional treatment
beyond atropine ; but if severe must be dealt with accordingly.
(See chap, v.) Sometimes small white spots resembling lead de-
posits form in the centre of the cornea ; they are quite superficial,
and can be easily removed with the point of a knife.

Diplobacillary conjunctivitis is not a very uncommon complica-
tion of trachoma, but when it occurs the patients do not always
present the well-know^n appearances of angular conjunctivitis. In
such cases sulphate of zinc relieves the acute symptoms considerably.

If the upper lid be tightly pressed on the globe, as it sometimes
is, the physiological lid-pressure varying in different individuals,
an impediment is offered to the cure by any method, and pannus
is promoted. It is then necessary to relieve the pressure by a
canthoplastic operation. (See chap, xix.)

The treatment of xerophthalmia, entropion, and such-like sequelse
is described under their respective headings.

Opinions differ as to the value of the treatment of trachoma
by X-rays, radium, and high-frequency currents. Carbon dioxide
snow is also being used at present.

In addition to the local treatment it is of great importance that
the hygienic surroundings of patients suffering from granular oph-
6

82 DISEASES OF THE EYE. [cnxv. in.

thalmia be seen to, and that they be obliged to spend a considerable
time daily in the open air.

As regards Proj)hijlaxis, patients should be warned of the danger
of infecting others. They should sleep by themselves in well-
ventilated rooms, observe habits of cleanliness, and have separate
towels, etc. Schools and public institutions should be inspected,
and if there be any cases of granular ophthalmia present, an ex-
amination should be made of all the inmates, and all persons affected
with the disease as well as suspicious cases should be isolated.

Follicular Conjunctivitis. — This is characterised by a catarrhal
inflammation of a mild type, to which is added the presence in the
conjunctiva of small round greyish or yellowish-pink follicles the
size of a pin's head, which disappear completely as the process passes
off, leaving the mucous membrane as healthy as they found it. The
follicles are situated chiefly in the lower fornix of the conjunctiva,
and may be discovered by e version of the lower lid, when they will
be seen arranged in rows parallel to the margin of the lid. Whether
they are easily discovered or not depends on their size and number,
and on the amount of co-existing hyper?emia or chemosis of the
conjunctiva.

Follicular conjunctivitis usually attacks both eyes, and is a
tedious affection, lasting often for months. It is met with chiefly
in children, and most frequently in schools. Systematic examina-
tions of the conjunctiva in schools have shown that a very large
number of the children have follicles in the lower fornix, and
occasionally they may be seen in the upper lids towards the angles.
In some cases post-nasal adenoids are associated with them. The
conjunctiva is otherwise normal, and in these cases the follicles
produce no irritation or distress of any kind. To this condition the
name " Folliculosis " is sometimes given, and it is believed that
it renders the eye more liable to catarrhal infection. When this
occurs, follicular conjunctivitis is the result.

The existence of lymph follicles in the normal conjunctiva is
disputed, and it is of course possible that, in cases in which they
are found, their presence may be explained by the repeated but
transient irritation, to which the conjunctiva, from its exposed
position, is constantly liable.

Considerable difference of opinion prevails as to the relation
of this disease to trachoma, some believing that it is merely a mild

CHAr. m.] THE CONJUNCTIVA. S3

or aborted form of the latter. The question cannot be definitely
settled until the real nature and cause of these two affections are
known. Clinically they seem to be distinct, and from our obser-
vation in this country, where both are common, there are no practical
reasons for regarding them as different forms merely of the same
disease. The chief points of difference between them are : — Folli-
cular conjunctivitis affects children, even in the upper-class schools ;
trachoma occurs at all ages, but mostly in adults, and is confined
to the lower classes. In follicular conjunctivitis the follicles are,
with rare exceptions, confined to the lower lid ; they are more
uniform in size and more regular in their arrangement than in
trachoma ; furthermore they never produce cicatrices, pannus,
or any of the ill effects which follow trachoma.

The Symptoms are much the same as those of catarrhal con-
junctivitis. Frequently there is little or no injection of the bul-
bar conjunctiva, and the chief symptom is asthenopia — an inability
to continue near work for any length of time — and much distress
in artificial light.

Causes. — These are much the same as in simple catarrhal con-
junctivitis. The long-continued use either of atropine or of eserine
is liable to bring on the disease.

Treatment. — The most useful remedy in this troublesome affec-
tion is an ointment of sulphate or citrate of copper of from gr. ss.
to gr. ij in 3j of vaseline. The weaker ointments should be used at
first, and later on the stronger ones if it be found that they cause
no excessive irritation. The size of half a pea of the ointment is
inserted into the conjunctival sac with a glass rod once a day. Eye-
drops of equal parts of tincture of opium and distilled water are
of use in some cases. Abundance of fresh air, with change from a
damp climate or neighbourhood to a dry one, is of importance.
If the use of a solution of atropine have induced the disease, it
should be discontinued ; and if a mydriatic be still required, a
solution of extract of belladonna (gr. viij ad gj) may be employed
in its stead.

In cases of folliculosis no local treatment is required. It may
be well to add that no alarm need be created in a school on account
of the occurrence of follicular conjunctivitis. The utmost that may
be necessary is the separation of those cases in which there is much
discharge, which might spread the catarrhal inflammation.

84 DISEASES OF THE EYE. [chap. hi.

* Tubercular Disease oi the Conjunctiva.— This disease affects
only one eye as a rule, and usually commences in the palpebral
conjunctiva of the upper lid or in the upper fornix, and very rarely
on the bulbar conjunctiva, in the form of a caseating ulcer, or as an
inflammatory new formation of the granuloma type. The granular
form occurs in the shape of small yellow or grey subconjunctival
nodules, resembling miliary tubercles, or may result in the develop-
ment of flattened outgrowths, cockscomb-like excrescences, or
even pedunculated tumours. The margins of the ulcers are well
defined, and their floors either of a yellowish lardaceous appearance,
or covered with greyish-red granulations. The surrounding con-
junctiva is swollen, and if the palpebral conjunctiva be much involved
the lid becomes enlarged in every dimension, and the ulcerative
process may soon destroy part of the lid. It is liable also to extend
to the bulbar conjunctiva, and the cornea may become covered
with pannus or affected with ulcerative keratitis. The preauricular
and submaxillary glands are usually enlarged. The discovery of
the tubercle bacillus would make the diagnosis positive, but as it not
infrequently happens that the bacilli elude detection owing to their
scarcity, while excised portions of the growths do not always show
a typical tubercular structure, one of the various tuberculine tests,
or inoculation experiments, may be necessary in order to remove
all doubt. The application of one or more of these methods of
diagnosis will serve also to distinguish this disease from secondary
syphilitic ulceration of the conjunctiva, between which and the
tubercular ulceration there is sometimes a resemblance. Moreover,
in the syphilitic ulcer the detection of the spirochfcta pallida, or the
application of ^Yassermann's test, would decide the diagnosis. The
granular form of tuberculosis may sometimes be suggestive of
trachoma, or even of a malignant growth. Tubercular conjunctival
disease is usually unattended by pain, or there is only a slight burning
sensation ; but, again, when the ulceration is extensive, severe pain
may set in.

The disease is very chronic, its progress sometimes extending
over many years. It is rarely met with except in youth. Some
of those whose eyes are attacked are already the subjects of tuber-
culosis in other organs, but very many of them are perfectly healthy
in that respect. In fact, there is reason to believe that tuber-
culosis of the conjunctiva is much more often a primary disease,

CHAP. III.] THE CONJUNCTIVA. 85

the result of an ectogenic infection, even in cases where already
tuberculosis exists elsewhere, than of infection occurring through
the blood. Tubercle bacilli introduced into the normal conjunctival
sac have, it is true, been found to be harmless, for the intact epithe-
lium offers an insuperable obstacle to their entrance into the tissue.
But a superficial loss of substance of the conjunctiva is sufficient
to allow of its inoculation with the bacilli, and then the disease
becomes established. The frequent lodgment of foreign bodies
under the upper lid explains why this is the situation in which the
disease most commonly begins. But although conjunctival tuber-
cular disease is not often secondary to tubercular disease in other
parts of the system, yet it is itself liable to be the starting-point
of general tuberculosis.

Treatment. — The fact last mentioned makes it most important, in
cases of primary tubercular disease of the conjunctiva, to thoroughly
eradicate the diseased focus so as to avert infection of other organs,
and this can often be effected. If the ulcers be not already too
extensive they must be curetted, and the actual cautery freely
applied. They may then be dusted with iodoform or lactic acid may
be applied pure or in 50 per cent, solutions. An ointment of 4 per
cent, picric acid in vaseline and lanolin, applied three times daily
to the diseased area, has proved useful in some cases. Injections of
tuberculin are also useful (see chap. vii.).

Parinaud's Conjunctivitis. — This well-defined form of subacute con-
junctivitis which may occur at any age was first described by Parinaud.
With very rare exceptions it attacks only one eye. The chief features
of the disease are : — The appearance of granulations or vegetations on
the tarsal conjunctiva or fornices, with painful and considerable en-
largement of the preauricular and neighbouring glands, on the same
side as the affected eye ; the disease is ushered in with chills and malaise ;
there is slight mucous, or fibrinous, secretion but no suppuration.

The upper lid becomes swollen and perhaps nodular to the touch,
and there is sometimes chemosis ; but the subjective eye-symptoms are
slight. The granulations are red or yellowish, and at first semi-trans-
parent, and they vary in size, being at times only as large as the head of
a pin, while again they may even form polypoid growths. Small yellow
granules and superficial erosions are often present, generally in the furrows
between the large granulations. The glandular inflammation sets in
along with, or immediately after, the eye-symptoms, and may end in
suppuration. The sub-maxillary and sometimes even the cervical glands
are affected. A complete cure results in the course of some months,
without any corneal complication or subsequent scarring of the con-

80 DISEASES OF THE EYE. [chap. hi.

junctiva. The last symptoms to disappear are the ptosis and glandular
enlargement.

Cause. — No case of the transmission of the disease to others has been
observed. The theory of an animal origin, which was originally advanced,
has not been proved. The histological changes, according to Verhoeff
and Derby, consist in areas of necrosis in the subconjunctival tissue and
extensive infiltration with lymphocytes, phagocytes, and plasma cells,
but no suppuration. The deeper layers are in a state of clu-onic
inflammatory reaction. The etiology is still uncertain ; in some cases
inoculation experiments gave undoubted evidence of tuberculosis, while
in others similar experiments failed. Verhoeff found a filamentous organ-
ism (? leptothrix) in ten out of twelve cases. Some authors regard the
disease as bovine tuberculosis. The only affections with which this disease
is liable to be confounded are trachoma and tuberculosis.

Treatment. — The disease tends to get well without treatment in the
course of a few months. Various remedies have been tried, but simple
antiseptic treatment is almost sufficient. The duration of the disease
may be shortened by excision of any large granulations, on the applica-
tion of the galvanocautery. If the glands suppurate, they should be
opened.

Ophthalmia Nodosa. — This disease is caused by the irritation (chemical
or mechanical) of the hairs of certain kinds of caterpillars. The hairs
give rise to ' foreign body ' granulomata, which appear as small nodules
chiefly on the lower part of the bulbar conjunctiva. Both clinically and
microscopically the condition bears a resemblance to tuberculosis, hence
it has also been called pseudo-tubercular conjunctivitis. The presence
of the hairs makes the diagnosis positive. In nearly all the recorded
cases there was a history of caterpillars having accidentally come into
forcible contact with the eye. The nodules are small, semi-translucent,
and reddish or yellowish grey in colour. The disease is chronic, as the
elimination or absorption of the hairs takes some time, but it terminates
in complete recovery, unless the hairs have made their way into the iris,
in which case a severe iridocyclitis may be set up.

Sporotrichosis, due usually to the S. Beurmanni, also produces an
irregular nodular appearance of the tarsal conjunctiva with superficial
ulceration and little secretion or increased vascularity. The preauricular,
and sometimes even the submaxillary glands become enlarged. Cultures
or inoculation may be necessary to distinguish it from tuberculosis. Iodide
of potassium in 10 to 20 grain doses is the best treatment.

* Lupus of the conjunctiva usually occurs as an extension ol the
disease from the surrounding skin, or rarely from the lacrimal sac.
It is seen as a patch or patches of ulceration, covered with small
dark-red protuberances or granulations, chiefly on the palpebral
conjunctiva, which bleed easily on being touched.

Like lupus of the skin, these ulcerations undergo spontaneous
healing and cicatrisation in one place (unlike tubercular ulceration

CHAP. III.] THE CONJUNCTIVA. 87

ill that respect), while they are still creeping over the surface in
another direction. But it is now known that lupus, wherever it
may occur, is a tubercular disease, and that the two forms differ
only in their clinical aspect.

Treatment. — Scraping with a sharp spoon, and the application
of the actual cautery. Iodoform. Tuberculin. X-rays.

* Syphilitic Disease of the Conjunctiva occurs both as primary
and as secondary disease. It will be treated of in chap, xviii., on
Diseases of the Eyelids.

Ulcers of the Conjunctiva. — In addition to tubercular and
syphilitic ulcers, the following conditions may lead to ulceration
of the conjunctiva : — Injuries, foreign bodies, the separation of
sloughs or membranes, pemphigus, epithelioma, smallpox ; phlyc-
tens also appear as small superficial ulcers on the bulbar conjunc-
tiva at one stage of their existence.

* Spring Catarrh, or Vernal Conjunctivitis. — In this extremely
chronic but rather rare disease, which, strictly speaking, is not a
catarrhal affection, the tarsal conjunctiva of the upper lid is occupied
by hard flattened bodies of a pale pinkish colour arranged close
together, and known as tesselated or pavement granulations (Fig. 43).
They are often slightly pedunculated. The conjunctiva assumes a
milky- white opalescence. The bulbar conjunctiva becomes injected,
slightly oedematous, and at the limbus somewhat elevated with
hard, gelatinous-looking and nodular greyish swellings in which
minute pale-yellow dots can often be seen (Fig. 44). The lower
palpebral conjunctiva is often milky-looking, but never shows granu-
lations. All these appearances may be present in the same case,
or any one (the bulbar appearances, or the pavement granulations,
or the milky- white opacity) or two of them may be absent. The
margin of the cornea itself is apt to be invaded with a more or less
circular infiltration resembling arcus senilis. Very occasionally the
cornea becomes seriously implicated owing to the growth on the
limbus extending over a great portion, or even over the entire
cornea. There is a scanty mucous or muco-purulent secretion, and
the patient may complain of the eyelids being stuck together in the
morning, of difficulty of using the eyes for near work, of itching and
burning sensations, and all these symptoms are increased by exposure
to heat. The eyelids droop slightly, giving the patient a sleepy look.

The condition of the upper lid might at first suggest granular

DISEASES OF THE EYE.

[chap. hi.

ophthalmia, from which it differs, however, in the solidity, absence
of transluceiicy, and tesselated arrangement of the ' granulations,'

which moreover do not
attack the fornix. The
pathological changes con-
sist in connective tissue
proliferation, hyaline de-
generation of the subcon-
junctival tissue, and
proliferation of the epi-
thelium, which sends solid
or cystic processes into
the stroma. It is still
uncertain which of these
is the primary change.
The conjunctival secre-
tion is very rich in eosino-
phil cells, a point which
cases.

Fig. 43. — Spring catarrh. Upper lid
everted.
From sketch by L. W.

would assist the diagnosis in doubtful

The affection is chiefly met with in boys between six years of
age and puberty, and is in most cases bilateral. The patients
sometimes look anaemic, and have in many cases enlarged lymphatic
glands. Blood changes are often present, and consist not so much
in an absolute increase of the white
corpuscles, as in a relative in-
crease of lymphocytes.

The disease makes its appearance
rarely in conjunction with heat erup-
tions on the skin, in warm weather
in the late spring or early summer,
and generally disappears, or is much
modified, in the cool seasons, to re-
turn again with the next warm
season; and this is liable to go on
for many years. In the intervals
between the attacks the congestion
and subjective symptoms disappear,
but the other appearances persist until recovery sets in

Fig.

44. — Circuincorneal growth
in spring catarrh.

Sketched by L. W.

This

disease has been attributed to the action of strong light,

CHAr. iii.l THE CONJUNCTIVA. 80

or to ultra-violet rays, but this is probably not the case. Although
an occlusive bandage often produces a rapid improvement, this is
not because of the exclusion of light, but on account of the protection
from the air, for the same result is attained by the use of well-fitting
goggles. We have recently seen a remarkably rapid improvement
follow the use of motor goggles. Exposure to snow in high altitudes
where the light is particularly strong is also beneficial owing to the
cool atmosphere. The cause of the disease is really unknown.

The Treatment of the majority of these cases yields unsatisfactory
results. Airtight goggles should be worn. So far as possible all
exposure to the heat of sun should be avoided. If possible the
patients should reside in a cool place in the summer. Weak astrin-
gent coUyria, or ointments, may be used ; or iodoform ointment
(1 in 15), a little put into the eye once a day ; or massage twice daily
in conjunction with yellow oxide ointment. Dilute acetic acid
1 or 2 minims to the 3J is also recommended. De Schweinitz recom-
mends borogiyceride locally, and arsenic internally. Antipyrin and
quinine internally have proved of use in some cases. Strong
salicylic acid ointment (20 grs. — 5J) has been recommended, but
we have tried it without much effect. Instillations of adrenalin
have proved very beneficial in some cases, and good results have
also been obtained with radium. It has been stated by one
surgeon that removal of adenoids and enlarged tonsils cures most
cases.

Pemphigus of the Conjunctiva. — This is another rare disease. It
has been seen in connection with pemphigus vulgaris of other parts of the
body, but it also occurs as an independent disease. It is attended by
attacks of much pain, photophobia, and lacrimation ; and the conjunctiva,
at each place where subconjunctival exudation of serum has been situated,
undergoes degeneration and cicatricial contraction. Such attacks succeed
each other at shorter or longer intervals, for weeks, months, or years,
until finally, the entire conjunctiva of each eye may have become de-
stroyed and the eyelids are adherent to the eyeball or to each other. The
cornea gradually becomes comjjletely opaque, or, having ulcerated, is
rendered staphylomatous. In the course of the disease the eyelashes
are apt to become turned in on the eyeball, or even entropion may follow.
The lacrimal puncta and canaliculi may become obliterated and the cilia
may disappear where the lids are adherent.

The foregoing is a description of a severe case. In less severe cases
the conjunctiva may not be completely destroyed, and the cornea may
not be affected.

Bullae are seldom seen, for the conjunctival epithelium is so delicate

DISEASES OF THE EYE,

[chap. III.

that the serous exudation beneath it- breaks it down at once. Conse-
quently, the conjunctival surface is found in these cases to be covered by
what looks like a membranous deposit, upon removal of which a raw
surface is exposed. These appearances have led to the mistaken
diagnoses of croupous and of diphtheritic conjunctivitis. Rarely deep-
seated bluish cysts are present.
They existed in the case illus-
trated by Fig. 45.

Treatment is helpless in re-
spect of arresting the progress of
the disease, or of restoring sight
when lost in consequence of it.
The most that can be done is to
relieve the distressing symptoms
by emollients to the conjunctiva,
^_ _ and, by the use of closely fitting

j(MX fe W^'^'^ ^'^''T^^ goggles, to afford protection

<c|||i\ c*' ' from wind, dust, and sun, In-

' ~^ ternally, arsenic is indicated.

Operation may relieve the sym-
blepharon and adherent eyelids.
Conjunctivitis Petrificans. —
Under this title Leber has de-
scribed a rare and remarkable
disease of the conjunctiva. In
the course of a brief period, and
accompanied by some slight in-
flammatory reaction, a stony
hard, white, chalky substance is
deposited, in more or less exten-
sive patches, in the previously healthy conjunctiva, the deposit being
scarcely raised over the conjunctival surface. The disease attacks a partof
the bulbar or palpebral conjunctiva, and may extend to the intermarginal
portion of the eyelid. One or both eyes may be attacked. After a time,
which varies from a week to several months, the deposit is thrown off or
absorbed, and the affected part suffers either no detriment or there may
be slight thickening and shrinking. There is no great tendency to corneal
complications, but slight marginal ulcerations, which heal readily, occa-
sionally occur. In one case severe diffuse opacity of the cornea seriously
affected the sight. Frequent relapses are liable to take place in the same
or in different parts of the conjunctiva, and the whole course of the affection
may extend over several years, and then end in complete cure.

No cause has as yet been assigned for this disease, although Leber
suspects it to be an ectogenic microbic infection. Warm fomentations,
and the careful operative removal froin time to time of the chalky scales
as they become loosened from the main mass, have been the chief features
of the treatment. Local instillations of diphtheria antitoxin were found
to give relief to the symptoms in the acute stage, in a case recently
recorded ; and in another, painting with benzoate of lithium solution
(1 in 40) proved very efficacious.

Fig. 4i

CHAP. III.] THE CONJUNCTIVA. 91

Subconjunctival Ecchymosis (Plate II. Fig. 6). — The rupture of
a small subconjunctival vessel in the bulbar conjunctiva, without
conjunctivitis, is of frequent occurrence. It suddenly gives a more
or less extensive purple hue to the ' white of the eye,' causing the
patient much concern. It is common enough as a spontaneous
affection in old people, and may be associated with arterio-sclerosis,
but it also occurs in the young, and even in children, from severe
straining, as in whooping-cough and vomiting. It is occasionally
significant of diabetes. It also occurs sometimes during epileptic
fits, and profuse subconjunctival haemorrhage is occasionally found
in cases of fracture of the base of the skull, the blood having made
its way along the floor of the orbit. It is of no importance so far
as the integrity of the eye is concerned.

Treatment. — The extravasated blood becomes absorbed without
treatment, but massage through the lids or dionine may accelerate
the process.

Subconjunctival Serous Effusion. Chemosis.— This has been
previously alluded to in connection with some forms of conjunc-
tivitis, but it may appear in inflammatory affections of the neigh-
bouring parts (orbit, lacrimal sac, eyelids). A stye for instance
is sometimes accompanied by well-marked chemosis. Dionine
also produces a serous exudation, which is preceded, however, by
an initial stage of congestion. In Bright's disease a slight degree
of chemosis often occurs. Tumours of the orbit may also produce
chemosis ; it is then non-inflammatory and the result of venous
stasis. A fistula of the anterior chamber at the limbus can also
give rise to a limited chemosis.

Treatment. — As a rule no special treatment is required beyond
that of the disease of which it forms a symptom ; but if it be
excessive the conjunctiva may be snipped with scissors, with very
good effect.

Emphysema of the Conjunctiva, when it occurs, is usually
associated with emphysema of the lids (see chap, xviii.).

Injuries of the Conjunctiva. — Foreign bodies frequently make
their way into the conjunctival sac, and cause much pain, especially
if they get under the upper lid, by reason, chiefly, of their coming
in contact with the corneal surface during motions of the lid and
of the eye. If the foreign body be under the lower lid it will be
easily found on drawnig down the latter, and, as it is rarely, if ever,

92 DISEASES OF THE EYE. [ch.aj. hi.

embedded in the mucous membrane of the lower lid, it can easily
be removed ; but if the foreign body be under the upper lid it is
necessary to evert the latter before it is reached. Should the foreign
body, which usually lodges in the subtarsal sulcus, be embedded in
the conjunctiva, it must be pricked out with the point of a needle
or other suitable instrument. For the effect of minute foreign
particles, e.g. dust, etc., see chronic conjunctivitis (p. 567).

Large foreign bodies, such as a grain of wheat, may lie hidden
in the upper fornix for several weeks. We have seen ulceration
of the cornea caused in this way, and also cockscomb-like granu-
lations in the fornix which resemble one form of tuberculosis of the
conjunctiva.

A tear or wound of the conjunctiva (usually of the bulbar portion),
when it occasionally occurs without injury to other parts, is in general
of very slight moment. If the wound be extensive its edges should
be drawn together with a few points of suture ; but otherwise
healing will take place with the aid simply of a bandage to keep
the eye closed for a few days.

A common form of injury, which may involve the conjunctiva
alone, is a burn by acid or lime. In the case of a strong acid getting
into the eye, if the patient be seen immediately after the occurrence,
the whole conjunctival sac should be well washed out with an, alka-
line solution (1 per cent, soda solution). In the case of lime, after
all the larger particles have been most carefully removed from the
eye with forceps, a weak solution of a mineral acid may be used for
washing out the conjunctival sac ; or, as is recommended by some,
a solution of sugar as thick as syrup may be poured into the eye.
Later, olive or castor oil, or even butter, may be applied, the sub-
sequent treatment being continued with weak sublimate ointment.
Cocaine may be employed to relieve the pain. But even in the
case of unslaked lime the conjunctiva may be washed Avith plain
water, provided plenty be used and that the operation be done
quickly. The heat generated by the slaking of the lime is developed
slowly, and further it is the chemical action rather than the heat
which is injurious.

In the case of a severe burn of the conjunctiva, the resulting
cicatrix is liable to produce a more or less extensive union of the
eyelid to the eyeball (Symblepharon), which often interferes with
the motion of the latter, or even with vision, if the cornea be ob-

CHAP. III.] THE CONJUNCTIVA. 93

scared. No measures taken during the healing process can prevent
symblepharon if the degree of the burn be such as to bring it about.
The relief of symblepharon by operation will be dealt with in chap,
xviii. on Diseases of the Eyelids,

Injury of the conjunctiva by a chip l)roken off an anihne pencil causes
a good deal of irritation, and the conjunctiva becomes intenseh'
stained. Tannic Acid 5 to 10 per cent, solution is recominended for the
treatment. In one such case which we have had, where the whole
bulbar conjunctiva was stained, washing out with a weak solution of
alcohol and subsequent treatment with glycerine drops, both of which
dissolve aniline violet, effected a complete cure in the course of a week,
and all traces of the stain were removed.

Degenerative Diseases.

Pinguecula (pinguis, fat) is the name given to a small yellowish
elevation on the exposed part of the bulbar conjunctiva near the
margin of the cornea, usually at its inner side, more rarely at its
temporal margin, but sometimes in each place. It is most commonly
seen in old people as a rounded tumour. Notwithstanding its name,
it contains no fat, but is composed of connective tissue, hyaline
deposits, and elastic fibres. It is supposed to be due to the irritation
caused by small foreign bodies. It rarely grows to a large size,
and requires no treatment unless it become very disfiguring, when
it may be removed with forceps and scissors. When an eye becomes
congested or ecchymosed, the pinguecula, if present, stands out as
a white or yellow patch and may be mistaken for a phlycten or
tumour.

Epithelial Plaques closely resemble epithelial xerosis ; they are slightly
raised, flat triangular patches close to the corneal margin, white or
yellowish in colour, and are due to alteration of the epithelium, which
becomes ejiidermal in character. These plaques are quite harmless.

Pterygium [jvTepvt, a wing).—T\\m is a vascularised thickening
of the conjunctiva, triangular in shape, situated most usually to
the inside of the cornea, sometimes to its outer side, but never above
or below it. The upper and lower margins of the triangle are limited
by a shallow depression or fold. The blunt apex of the triangle,
or head of the pterygium, lies on the cornea ; its base is at the semi-
lunar fold or outer canthus as the case may be, while the neck is
situated at the limbus. The growth frequently, but not always,
exhibits a tendencv to advance into the cornea, the centre of which

1)4 DISEASES OF THE EYE. [chap. tit.

it seldom reaches, and yet more rarely does it extend quite across
the cornea.

In its early growth the pterygium is somewhat thick and succu-
lent looking, and very vascular ; but finally it ceases to grow, and
then becomes thin and pale, and this is its retrogressive stage ; yet
it never entirely disappears. Sight is not affected unless the ptery-
gium extend over the pupillary region of \.h.& cornea. A limitation
of the motion of the eye to the other side, and consequent diplopia,
is sometimes caused by a pterygium ; but, for the most part, it
is the disfigurement alone which brings these cases to the surgeon.

Cause. — It was formerly believed that the starting-point of
a pterygium was an ulcer at the margin of the cornea, which in
healing caught a fold of the limbus conjunctivae and drew it towards
the cicatrix, throwing the mucous membrane into a triangular
fold. But ulcers are never found at the apex of a true pterygium,
and the condition brought about in this manner is known as pseudo-
pterygium and differs in many ways from true pterygium. The
false pterygium may occur at any part of the circumference of the
cornea. It is very variable in shape, is non-progressive, and in
most cases a fine probe can be passed under the neck of the growth
where it bridges over the limbus. Again, in a false pterygium a
nebula or leucoma is frequently found at the apex.

Fuchs believes that pterygium develops from a pinguecula,
and that the latter causes nutritive changes in the cornea, loosening
the superficial lamellae, and allowing the connective tissue of the
limbus to grow in on the cornea.

Pterygium is not a common affection in this country ; it is
most frequently met with in sandy or dry countries.

Treatment. — Unless the pterygium be very thick, and have in-
vaded the cornea to some extent, or be progressing over the cornea,
it is well to let it alone ; the more so as by removing it the appear-
ance given to the eye is not quite normal, for a mark is necessarily
left both on cornea and conjunctiva. If it be progressive or very
disfiguring, it should be removed. This may be effected either by
ligature, excision, or transplantation.

In the method by ligature a strong silk suture is passed through
two needles. The pterygium being raised with a forceps close to
the cornea, one needle is passed under it here and the other needle
in the same way close to its base, the ligature being drawn half-

CHAP. TIT.] THE CONJUNCTIVA. 05

way through. The thread is cut close behind each needle, thus
forming three ligatures, which are respectively tied tight. In four
or five days the pterygium comes away.

For excision the apex is seized with a forceps and dissected
off, either with a scissors or fine scalpel, care being taken not to injure
the true cornea ; or a good plan is to pass a strabismus hook under
the pterygium when raised up from the sclerotic, and to forcibly
separate the corneal portion by drawing the hook under it. The
dissection is continued towards the base of the pterygium, where
it is finished with two convergent incisions meeting at the base.
The mucous membrane in the neighbourhood of the base is separated
up somewhat from the sclerotic, and the margins of the conjunctival
wound are then brought together with sutures.

McReynolds's method of transplantation is a good one. The neck
of the pterygium is grasped with a forceps and transfixed as close as
possible to the globe with a sharp cataract, or special knife, with
which every particle of the growth should be shaved ofi the cornea
until only clear cornea is left. The conjunctiva is then divided along
the lower margin of the pterygium from neck towards canthus for a
distance of J or J an inch. The body of the growth is next separated
from the underlying sclera, and the conjunctiva below the incision
loosened with scissors so as to form a pocket. A black silk thread
armed with two needles is passed through the apex of the pterygium ,
the needles are then carried under the loosened conjunctiva, J of
an inch apart, and made to emerge close to the lower fornix. The
edge of the loosened conjunctiva is now" raised and by gentle
traction on the sutures the pterygium is made to glide into the
conjunctival pocket, and the sutures are tied. It is important to
remove every trace from the cornea and also not to divide the con-
junctiva above the growth; the conjunctiva should however be
undermined and freed from the limbus in the neighbourhood of the
neck.

Pterygia sometimes recur even after repeated operations, and
in rare instances a fleshy mass may be formed which renders the
condition of the eye worse than it had been originally. In such
an event the growth must be dissected up with a surrounding portion
of conjunctiva and reflected towards the canthus, and on the large
area of exposed sclera, carefully cleaned, a Thiersch skin graft or
a flap of mucous membrane from the lip should be applied ; the

Ofi DISEASES OF THE EYE. [ciiAr. iii.

flap margins may be inserted under the edges of the conjunctival
incision. It is recommended that the graft should be pressed firmly
down on the raw surface while the lids are held open for three to
five minutes before the bandage is applied.

* Lithiasis consists in the calcification of the secretion of the
Meibomian glands, which are seen as small white or yellowish spots
not larger than a pin's head in the conjunctiva. There may be one
only, or very many. Concretions similar to these but more super-
ficial also occur in the lower fornix ; they are found in the interior
of newly formed glands which have become cystic. These con-
cretions often give rise to much conjunctival irritation, and if they
protrude over the surface of the conjunctiva may injure the cornea.
Each one — the eye having been cocainised — must be separately
removed by a needle, an incision having first been made with it in
the conjunctiva over the concretion.

Uric acid deposits have been observed in the palpebral conjunc-
tiva in gouty patients.

Xerosis {tvp^^, dry), or Xerophthalmos, is a dry, histreless condition
of the conjunctiva, associated in the severer forms with slirinking of the
membrane. There are two forms of the affection — the parenchymatous,
which is a local affection, and the epithelial, which is associated with
general malnutrition.

In Parenchymatous Xerophthalmos there is a more or less extensive
cicatricial degeneration of the conjunctiva, dependent upon changes in its
deeper layers, while its surface and that of the cornea become dry, and the
latter becomes opaque, and the eye consequently sightless. The conjunctiva
shrinks so completely, in many of these cases, that both lids are found
adherent in their whole extent to the eyeball, which is exposed merely
at the palpebral fissure, where the opaque and lustreless cornea is to be
seen. From what remains of the conjunctiva, scales, composed of dry,
horny epithelium, fat, etc., peel away, and the lacrimal secretion, which
is much diminished in quantity, rolls off the oily surface of the keratinised
epithelium. The motions of the eyeball are restricted in proportion to
the extent of the conjunctival degeneration. There is no cure for this
condition.

Fig. 45 represents a case of xerophthalmos, tlie result of pemphigus,
which occurred in a patient at the Royal Victoria Eye and Ear Hospital.
Here the eyelids were not wholly adherent to the eyeball, and the cornea
remained clear.

The Causes of parenchymatous xerosis of the conjunctiva are granular
ophthalmia, diphtheritic ophthalmia, pemphigus, burns, exposure of the
eye from exophthalmos, and the condition is said to be very occasion-
ally seen as a primary disease, described as essential shrinking of the
conjunctiva. ]Many observers altogether deny the existence of this primary

CHAP. III.] THE CONJUNCTIVA. 97

disease, and maintain that the cases described as being of that nature are
merely the result of pemphigus, and we are inclined to agree with this
view.

Treatinent. — As cure is impossible in this form of xerophthalmos,
the only indication is to afford relief, so far as it can be done, from the
distressing sensations of dryness of the eyes which are complained of.
The best applications are milk, glycerine, olive oil, and weak alkaline
solutions, and the eyes should be protected from all irritating influences
by protection goggles. Transplantation of mucous membrane, or tem-
porary union of the lids, produces as a rule only a transient improvement.

Epithelial Xerosis of the conjunctiva is confined to the epithelium
of that part of the conjunctiva which covers the exposed portion of the
sclerotic in the palpebral opening. It there becomes dry and dull and
covered with a white foam due to altered Meibomian secretion. The
xerotic patches, which are triangular in shape, with the base at the corneal
margin, are known as Bitot's Spots. The whole bulbar conjunctiva is
loose, and easily thrown into folds by motions of the eyeball, and there
may be a good deal of secretion. This form of xerophthalmos often
occurs in epidemics, but also sporadically, accompanied by night-blind-
ness (the light-sense unimpaired) and contraction of the field of vision.
When combined with night-blindness the condition has been noticed
chiefly in persons of debilitated constitution, who have been exposed to
strong glares of light, and is said to have appeared in epidemics, under
these conditions, in foreign prisons and barracks. Epidemics have been
chiefly seen in Russia, especially during the Lenten fasts. The disease
has been found to be associated with a reduction of the haemoglobin index,
and it has also been attributed to deficiency in the fat content of the blood.

The dryness of the conjunctiva is due to cornification. of the epithelium,
which the tears cannot properly moisten. Xerosis bacilli are found in
large numbers, but are not the cause of the disease.

Treatment by rest, protection from glare of light, nutritious diet, and
tonics, especially cod-liver oil, invariably restore the eyes to their normal
functions.

Again, epithelial xerosis occurs in very young cachectic children, in
connection with a destructive ulceration of the cornea (see Keratomalacia,
chap. v.).

Hyaline, Colloid, and Amyloid Degeneration.— This very rare disease
is a primary affection of the conjunctiva, and is not associated with amyloid
disease in any other part of the system. It has been found combined
with granular ophthalmia, but this was most likely due to a fortuitous
coincidence of the two diseases. It is most frequently met with in patients
between twenty and twenty-five years of age, generally in one eye only,
and it is extremely chronic, lasting for years. The retro-tarsal folds and
palpebral conjunctiva are chiefly attacked, but it may also involve the
bulbar portion. It causes great tumefaction of the affected lid, without
any inflammatory symptoms. The eyelid can be but partially elevated,
and is often so stiff and hard that it can only be everted with difficulty.
The conjunctiva is yellowish, wax-like, non-vascular, and friable. The
disease ultimately extends to the tarsus,

DISEASES OF THE EYE.

[CHAP. III.

Microscopically, homogeneous masses ar

e fouud in tlie conjunctiva,

with variable staining properties, according to which they are called
Amyloid Hyaline, or Colloid. Calcification occurs in the later stages.
Ra^hhnaiin believes that the amyloid changes are always preceded by
lymphoid hifiltration. Figs. 4G and 47 are from a case in the Mater hospital
which presented the clinical appearance of amyloid disease with the
histological structure of a purely lymphoid thickening.

Treatment.— A partial removal of the diseased parts by the knife or

Fig. 46. — Lymphoma of
conjunctiva.

FiC4. 47. — Same case
as Fig. 40.

scraping is all that is necessary, as the remainder disappears spontane-
ously, and further excessive scarring is thus avoided. A very good result
was obtained in the above case by this method.

Cysts.

Simple Cysts of the conjunctiva are very rare. They appear as clear
spherical protuberances of about the size of a pea, seated usually on
the bulbar conjunctiva. The walls of the cysts contain but few vessels,
are thin, and almost transparent ; while for contents they have a clear
limpid fluid. These cysts cannot as a rule be moved from their position,
because they are adherent to the conjunctiva, which indeed takes part
in the formation of their walls. The majority are dilated lymphatic vessels,
as shown by their endothelial lining. Small beadlike strings of dilated
lymphatics are very frequently seen on the bulbar conjunctiva. Retention
cysts are also developed in Henle's and Krause's glands, as well as in the
so-called glands resulting from clironic inflammatory conditions. Im-
plantation cysts, due to proliferation of included surface epithelium, occur
as the result of injury, and congenital cysts are also met with.

Treatment. — The cyst may be dissected out, or it may suffice to abscise
its anterior wall, and to scrape or cauterise the interior.

Subconjunctival Cysticercus is a little more common than simple
cyst of the conjunctiva. It is distinguished from the latter by its free
mobility under the conjunctiva, to which it is not attached, by its thicker
and more vascular walls, and, above all, by the presence of a round,
white, opaque spot on the anterior surface, first pointed out by Sichel,

CHAP. III.] THE CONJUNCTIVA. 99

and looked on by him as pathognomonic of a cysticercus. This spot
indicates the position of the receptaculum, and occasionally, when this
comes to be placed on the posterior surface of the cyst, it may be difficult,
or impossible, to make the diagnosis with certainty, but in doubtful cases
the character of the booklets and the tuberculated cyst-wall will solve
the question after the excision.

Treatment. — The cyst may be pushed to one side under the conjunctiva,
an incision made in the latter, the cyst then pushed back again, and
dissected out through the opening.

Tumours.

Solid tumovirs of the conjunctiva may be divided into congenital
(Lipoma, Nsevus) and acquired; the latter are benign (Papilloma,
Angioma, Lymphoma, etc.) or malignant (Epithelioma, Sarcoma).

Dermo-Lipoma occurs as a fibro-fatty congenital tumour, usually situ-
ated between the superior and external
recti muscles. They are not encap-
suled, and the fatty portion of these
tumours is continuous with the orbital
fat. Pure lipoma is exceedingly rare.
Fig. 48 represents a dermo-lipoma in an
unusual situation. The patient sought
relief on account of the irritation
caused by the long hairs which were
only noticed about puberty.

Osteoma is a very rare congenital
tumour, which occurs in the same ^ig. 48.— Dermo-lipoma with
situation as the dermo-lipoma. nans.

Naevus (or Mole). — This congenital
and usually pigmented growth appears most commonly at the limbus, as
a brown spot, or as a flat gelatinous looking swelling, of a brown or
reddish colour. It may be stationary, or may become progressive at
puberty. The pigmented variety occasionally forms the starting point of
a pigmented sarcoma. Microscopically a conjunctival nsevus consists of
epitheHal downgrowths combined with groups or alveoli of smaller so-
called nsevus cells, the origin of which is doubtful. Cases which have
been described as benign epithelioma and dermo-epithelioma were most
probably unpigmented naevi.

Treatment. — If the naevus be disfiguring or progressive it can easily
be excised.

Hsemangioma (Vascular Nsevus). — This is generally met with in young
people and is often congenital, but is sometimes the result of injury. It
may be capillary or cavernous, and is liable to increase in size. It occurs
along with the same conditions of the lids, but also separately, especially
on the plica or caruncle.

Treatment. — Electrolysis or ligature. Good results have been obtained
with ethylate of sodium, carefully painted on, and with carbon dioxide
snow»

100 DISEASES OF THE EYE. [chap. hi.

Polypus and Granuloma. — True mucous polypi never occur on the
conjunctiva. The growths, to which the name of polypus is given, are
tumours of different kinds which become pedunculated owing to the
movements of the lids and eyes ; they are fibromata or papillomata.
Granulomata, or granulation tissue, occurring after operations (squint,
enucleation, chalazion) or f>roduced by foreign bodies, or even by tuber-
culosis, may also assume a polypoid form. The soft fibromata are some-
times the cause of bloody tears.

Lymphoma. — Diffuse lymphoma of the conjunctiva occurs in leukaemia
or pseudo-leuka?mia, but also as a primary affection, which is probably an
early stage of amyloid disease (see Figs. 46 and 47). Small lymphomatous
or lympho-sarcomatous tumoiu-s are met with rarely, chiefly at the inner
canthus. Some of the cases described as lymphoma were examples of
Parinaud's disease.

Papilloma, or Papillary Fibroma. — This is a non-malignant growth,
which may spring from any part of the conjunctival sac. It may occur
at any age, and several tumours may be present. It is much more common
in men than in women. It appears in the beginning as a small round
red knob. The papillomata growing from the tarsal conjunctiva and

from the semi-lunar fold frequently
take on a cauliflower appearance ;
while on the bulbar conjunctiva and
in the fornix the growths are liable
to be pedunculated, with a papillary
surface. The limbus of the con-
junctiva is a favourite seat for a papil-
loma (Fig. 49), and in the early stage
it may be impossible to disting\iish it
from an epithelioma. But at a later
stage, when the growth has overlapped
the cornea, the papilloma merely
Fig. 49. — Papilloma growing at overlies it and can be lifted freely off it
the limbus. with a probe, while the epithelioma.

Sketched by L. W. as a rule, infiltrates the corneal tissue.

Moreover, enlargement of the pre-
auricular gland only occurs in the latter. But it must be remembered
that papillomata in elderly people sometimes become malignant.

Treatment. — Thorough removal with knife or scissors, followed by the
actual cautery, as otherwise the growth is liable to recur.

Malignant Tumours (Epithelioma, Sarcoma). — These rare growths
generally take their origin in the limbus, most frequently at the temporal
side. They are often extremely slow in their growth, lasting perhaps
several years before attaining any considerable size.' They are epibulbar
tumours, that is to say, they spread on the surface of the eyeball and very
rarely penetrate it. They may be pigmented or not. The pigmentation
is explained by the fact that the limbus contains pigment, although gener-
ally so slight in amount as not to be visible to the naked eye. There is
no cachexia, and the liability to metastases is less than in the case of
intra-ocular growths, but the tendency to local recurrences is very great.

CHAP. III.] THE CONJUNCTIVA. 101

The disease is rarely met with under forty years of age. On account of
the alveolar structure so often present in these tumours, differences of
opinion not infrequently arise in the effort to distinguish between sarcoma
and epithelioma. The tumour soon becomes surrounded by a localised
congestion, and, as it grows, it interferes with sight and prevents closure
of the lids, but does not cause much pain until the late stages, when ulcera-
tion and hcemorrhage are apt to occur.

Ej)itheliomata are usually non-pigmented, and at first may be mistaken
for phlyctens — of which, however, the margins are not so steep — or for
papillomata {vide supra). The surface is wart-like or papillary, or it may
be nodular, but the nodules are not so smooth nor so large as in a sarcoma.
The cornea becomes infiltrated by the growth and the lymphatic glands
may bo enlarged.

Sarcomata on the other hand are generally pigmented, the tumour is
smooth or nodular, and rarely polypoid, and when it extends over the
cornea, is not adherent to it, or at least does not involve it except in a very
late period.

But conjunctival sarcoma also starts from other parts of the conjunctiva,
and in a case at the Royal Victoria Eye and Ear Hospital sarcomatous
tumours were four times removed from different parts of the fornix, an
interval of some months elapsing between the appearance of each small
tumour, and finally enucleation became necessary. Malignant growths
on the eyelids often involve the conjunctiva secondarily, and this is a
common occurrence in rodent ulcer.

Treatment, — Both epithelioma and sarcoma of the conjunctiva demand
prompt operative removal, in order to prevent an extension of the growth
to the rest of the eye, as well as to avert metastases to other organs. The
knife and actual cautery may save the eye and the patient's life in the
early stages. When a recurrence takes place it is safer to remove the
eye, more especially if the patient cannot be kept under constant super-
vision.

Tumours of the Caruncle. — A great variety of tumours, benign or
malignant, may grow from the caruncle. They may arise from the
epithelium, or conjunctival stroma, and may be dermoid, lymphomatous,
or sarcomatous.

CHAPTER IV.

PHLYCTENULAR CONJUNCTIVITIS, AND KERATITIS.

Both from a clinical and nosological point of view it would be
incorrect to divide this affection into two, under the heads of Diseases
of the Conjunctiva and Diseases of the Cornea ; therefore it is
treated of here as one disease, and on account of its importance a
special chapter is given to it. It is important, because it is ex-
cessively common, and because it is capable of causing considerable
damage to sight. Moreover, even when it occurs on the cornea, it
might, strictly speaking, be regarded as a conjunctival disease,
for the layer of the cornea, which it primarily attacks, is the epithe-
lium, and this — and probably also Bowman's membrane and the
anterior layers of the true cornea — as we know from the foetal develop-
ment of the membrane, is a continuation of the conjunctiva in a
modified form over the cornea.

The disease is characterised by the eruption of phlyctens {(jiXvKTaiva,
a vesicle, or pustule) on the conjunctiva bulbi, on the conjunctival
limbus, or on the cornea. It is chiefly a disease of children up to
the eighth or tenth year of age. It is seen occasionally in adults,
especially in women. The appearance of the phlycten is preceded
by a localised patch of ciliary congestion, which remains for some
time after the phlycten has healed (Plate II., Fig. 3).

Notwithstanding the derivation of the word, a phlycten is
originally neither a vesicle nor a pustule. It is a formation sui
generis, and, when on the conjunctiva, is a solid elevation consisting
of leucocytes, and some lymphocytes, also giant cells and epithelioid
cells, and is of a greyish colour. In a late stage the phlycten, especi-
ally on the cornea, may become a pustule by infection. On the con-
junctiva two types of the disease can be recognised : —

1. The Solitary, or Simple, Phlycten.— Of this there may be
one or several, varying in size from 1 mm. to 4 mm. in diameter.

102

CHAP. IV.] PHLYCTENULAR CONJUNCTIVITIS. 103

The vascular injection is immediately around the phlycten, and is
not diffused over the conjunctiva, yet it is true that occasionally
any form of phlyctenular disease may be associated with simple
conjunctivitis, which is to be regarded as secondary to the phlyc-
tenular affection. At first there may be shooting pains and lacri-
mation, but these soon pass away. If the phlyctens be not seated
close to the cornea the affection is not serious ; and the length of
time required for its cure depends on the size of the phlyctens,
varying from seven to fourteen days, as a rule.

2. Multiple, or Miliary, Phlyctens.— These are very minute,
like grains of fine sand, and are always situated on the limbus of
the conjunctiva, which is swollen. The general injection and
swelling of the conjunctiva are considerable, and there may be a
good deal of conjunctival discharge ; and, occurring as it does almost
exclusively in young children, the affection may be called Ecze-
matous Conjunctival Catarrh of Children (Horner). The irritation,
and so-called photophobia, and lacrimation are often considerable.
This form is very apt to appear after measles and scarlatina.

Both forms are liahle to extend to the cornea, and then only does
the disease become serious. This event may come about in the
following different w^ays : —

The Solitary Phlycten may be seated partly on the limbus con-
junctivae and partly on the margin of the cornea, and may undergo
resolution.

Or, it may give rise to a deep ulcer, which either heals, leaving
a scar, or perforates, causing prolapse of the iris, etc.

Or, it may form the starting-point of a fascicular keratitis, the
pustule becoming an ulcer, at the margin of which the corneal
epithelium is raised and infiltrated in crescentic shape. This now
steadily advances for many weeks towards the centre of the cornea,
followed by a leash of vessels which has its termination in the
concavity of the crescent. The process is accompanied by much
irritation of the terminal branches of the fifth nerve in the
cornea, and the consequent reflex blepharospasm. A permanent
mark indicates the track of the ulcer.

The Multiple Miliary Phlyctens on the limbus conjunctivae may
cause some slight superficial infiltration and vascularisation of
the cornea in their immediate neighbourhood, which pass off when
the phlyctens disappear.

1U4 DISEASES OF THE EYE. [chap. iv.

Or, they may be accompanied by deeper marginal infiltrations
of the cornea, which become confluent and result in an ulcer that
extends along the margin of the cornea for some distance, forming
a ring ulcer. It is a serious form of ulcer ; for, if it extend far around
the cornea, it may destroy the latter in a few days by cutting off
its nutrition.

The only condition which may give rise to an error in diagnosis is a
patch of sclerilis (chap. vi.). In scleritis the vascular injection is deeper
than the conjunctival vessels, and of a more purple colour (Plate II.,
Fig. 5) ; the affected part is usually tender on pressure, and there is
no vesicular or pustular formation on it.

Primary Phlyctenular Keratitis occurs principally in three
different forms :^(1) Very small grey sub-epithelial infiltrations,
which are apt to result in small ulcers, and then heal, leaving a slight
opacity. This opacity may ultimately quite disappear, especially
in the case of children, and when situated peripherally. (2) Some-
what larger and deeper infiltrations, resulting in ulcers of correspond-
ing size, which heal by aid of vascularisation from the margin of
the cornea. The opacity left after these ulcers is rather intense,
and clears up but little, especially if the situation be central. (3)
Large and deep-seated pustules, due to secondary infection, often
at the centre of the cornea, giving rise to large and deep ulcers,
which may be accompanied by hypopyon and even by iritis, and
which frequently go on to perforation.

Photophobia is usually a prominent symptom in phlyctenular
keratitis, and the blepharospasm often causes eczematous fissures
at the outer canthus. The term photophobia, however, is not
altogether correct, for it is the fifth nerve (from the cornea)
which is mainly the afferent nerve here, rather than the optic
nerve. This is evident from the fact that in the dark the patient
does not get complete relief. The explanation of this reflex
blepharospasm has been given by Iwanoff, who showed that the
cells which go to form the phlycten follow the course of the nerve
filaments, which they must irritate in their progress. (Figs. 50 and
51 are after Iwanoff.)

Enlarged cervical glands, eczema of the eyelids, face, and
external ear, and rhinitis, frequently accompany phlyctenular
conjunctivitis and keratitis.

In these cases, in children of three or four years of age, temporary

PHL YGTEN ULAR CON J UNCTI VITIS.

105

Fig. 50. — E, Epithelium ; B, Ant, elastic
Lamina ; C, True Cornea ; N, Nerve Fila-
ment, with Lymph Cells on its course ; D,
Phlyctenula.

amaurosis has sometimes been observed after a severe and long-
continued blepharospasm has passed away. The patient is found

to be unable to see even
large objects, or to find
his way, although the
pupil-reflex is active,
and a strong light may
still be distressing.
There are no ophthal-
moscopic appearances.
This blindness passes
away completely,
usually in from two to
four weeks, although
the interval before re-
covery of sight may be
several months. A certain mental dullness, which also ultimately
disappears, is noticed in some cases. This temporary loss of sight
has been held by some to be due to disturbance of the intra-ocular
circulation, and of the nutrition of the retina from pressure of the
eyelids on the eyeball. It has been regarded by others as having a
cerebral origin of a functional nature ; for it is likely at this tender
age, when the psychophysical processes are not as yet firmly estab-
lished, that the desire not to see, and the active withdrawal from
the act of vision, may lead in a short time to a functional paralysis
of the visual centres in the brain ; and these centres may take
some time to recover, or to
re-learn, their functions,
when the ground for the sus-
pension of the latter has
ceased.

As a result of frequent re-
lapses of phlyctenular kera-
titis, a superficial pannus-like
vascularisation may form in

the cornea, in those parts of it which have been chiefly attacked.
In many cases the cornea presents the appearance of ill-defined
irregular opacities, due to the combination of fresh phlyctens
with the nebula left by previous attacks of the disease.

Fig. 51.

lOG DISEASED OF THE EYE. [chap. iv.

An indolent form of ulcer is sometimes met with, known as
Absorption ulcer (Facetted Ulcer). It is accompanied by but little
opacity and by no vascularisation, and is usually seated at or near
the centre of the cornea, where it presents the appearance of a shallow
pit. The healing process may take months to be completed, and
slight opacity remains. Often the defect is never quite filled up,
but a small facet is left, which is liable to interfere with vision.

The absorption ulcer does not tend to perforate, nor to spread
over the surface of the cornea.

Cause. — As already stated, this is a disease of childhood,
although it is extremely rare in the first year of life. In adults it
is uncommon.

The strumous constitution — as indicated by the swollen nose
and upper lip, and sometimes by the enlarged lymphatics in the
neck, and by the eczema — which is allied to, if not indeed a form of,
tuberculosis, is that most liable to this affection. Often, however,
it will be found in strong children with apparently perfect general
health ; but even in them there is probably some irregularity of
nutrition, of which the great tendency to recurrence of the eye
affection is evidence.

The suspicion that phlyctenular disease is often a manifestation
of tuberculosis has been gaining ground. The evidence in favour of
this view is : — That the instillation of tuberculin into the conjunctival
sac sometimes produces a crop of phlyctens. That giant cells and
epithelioid cells have been found (Leber) in phlyctens. That the
opsonic index for tubercle has been found (Nias and Paton) to be
low in cases of phlyctenular disease, and that Von Pirquet and tuber-
culin tests are positive in the vast majority of cases. On the other
hand tubercle bacilli have not been found in phlyctens and inocula-
tion experiments have not produced tuberculosis in animals. It is
now believed that the disease is caused by the toxins of tubercle
bacilli, and that irritants of different kinds, staphylococci for instance,
acting in tuberculous patients may induce it. Tubercular disease
in other parts of the body cannot always be detected in these patients,
but tubercular cervical glands and tubercular disease of the bones
are present in a fair proportion of the cases.

Treatment. — The solitary phlycten of the conjunctiva is best
treated with a 2 per cent, yellow oxide of mercury ointment, of
which a portion of the size of a hemp-seed should be put into the

CHAP. IV.] PHLYCTENULAR CONJUNCTIVITIS. 107

eye with a small glass rod, once a day. To obtain the best result
with this ointment, its base should consist of 10 parts of pure white
vaseline, and one part each of anhydrous lanoline and water. The
yellow oxide is to be freshly precipitated and in very fine powder,
and when it has been well rubbed up with the water, the anhydrous
lanoline and vaseline are added. This ointment contains no fatty sub-
stance, and consequently mixes with the tears and comes thoroughly
in contact with the surface of the eye. Ordinary lanoline contains
olive oil. The ointment should not be unnecessarily exposed to light
or air. A little pure calomel insufflated into the eye once a day will
also cure ; but this remedy should not be employed if iodide of
potassium is being taken internally, for then iodide of mercury is
liable to be formed in the conjunctiva.

Miliary phlyctenular conjunctivitis, when accompanied with a
muco-purulent discharge, may be treated by the application of Sol.
argent, nitr. (gr. v ad §j) to the everted conjunctiva, or one of
the organic silver salts may be used instead; if the phlyctenular
appearance predominate over the catarrhal, the yellow oxide of
mercury ointment or insufflations of calomel may be preferred.
Indeed, practically, the two latter remedies are applicable in all
these cases.

When the cornea is slightly affected near the margin, warm
fomentations should be used in addition.

Where a large pustule on the margin of the cornea has resulted
in a deep ulcer, with tendency to perforate, and is accompanied by
much pain, paracentesis of the anterior chamber through the floor
of the ulcer, the pupil having first been brought well under the
influence of eserine to prevent prolapse of the iris, cannot be too
strongly advocated. The good effect of this will be very soon
apparent : the pain disappears, the patient sleeps, the ulcer becomes
vascularised, and healing sets in. Cauterisation of the ulcer in
an early stage with the galvano-cautery is also good practice ;
but in these cases paracentesis is preferable. Many surgeons
trust too much to eserine, warm fomentations, and a pressure
bandage.

For the fascicular keratitis the yellow oxide of mercury oint-
ment is again in its place. When the crescentic infiltration is very
intense it is well to touch it with the galvano-cautery.

For the ring ulcer a pressure bandage, under which an anti-

108 DISEASES OF THE EYE. [chap. iv.

septic dressing (boric or salicylic acid, or perchloride of mercury)
has been placed, is, perhaps, the best method of treatment. Warm
fomentations promote vascular reaction, and may be used with
benefit at each change of bandage.

For primary phlyctens of the cornea, in the form of the minute
grey superficial infiltration or ulcer, nothing beyond atropine, with
warm fomentations and a protective bandage to keep the eyelids
quiet, should be used. When reparation of the ulcer has com-
menced, insufflations of calomel or weak yellow oxide of mercury
ointment may be employed.

For the large infected phlycten, resulting in -a large and deep
ulcer, often situated at the centre of the cornea, with hypopyon
and iritis, warm fomentations (camomile, or poppy-head, at 90°
Fahr., for twenty minutes three times a day), atropine, boric acid,
xeroform or iodoform as ointment or powder, and a protection band-
age form the treatment in the early stages. Here, also, the ulcer
may be punctured with the very best results in respect of hastening
the cure, or the galvano-cautery may be used with advantage. In
the stage of reparation the yellow oxide of mercury ointment or
insufflations of calomel are very useful.

In nearly all cases of phlyctenular keratitis dionine (5 per cent,
solution) aids the cure.

In all forms of phlyctenular ophthalmia those favourite remedies,
blisters, setons, and leeching, should be avoided. The first two
worry the patient, give rise to eczema of the skin, and are not to
be compared in their power of cure with the measures above recom-
mended ; while leeching gives, at best, but temporary relief, and
deprives the patient of blood which he much requires.

If the blepharospasm be obstinate in spite of the use of atropine,
plunging the child's face into a basin of cold water is most efficacious.
The face is kept under the water until the patient struggles for
breath, and this immersion is repeated two or three times in rapid
succession, and used every day if necessary. The beneficial effect
is often most remarkable.

The general treatment, notwithstanding the so-called photo-
phobia, should consist in open-air exercise, unless, indeed, there be
an ulcer which threatens to perforate. It is not well to keep the
eyes (unless there be a corneal ulcer), or patient's face, covered with
bandages or shades, nor to confine him to a dark room. A pair of

CHAP. IV.] PHLYCTENULAR CONJUNCTIVITIS. 100

smoked glasses are the best protection from strong glare of light ;
and shady places can be selected when the patient is out of doors.
Cold or sea baths, followed by brisk dry rubbing. Easily assimilated
food at regular meal hours, but no feeding between meals. Regula-
tion of the bowels. Internally : cod-liver oil, maltine, iron, arsenic,
syrup of the phosphate of lime, and such-like remedies are indicated.

The great tendency to recurrence is one of the most trouble-
some peculiarities of all kinds of phlyctenular ophthalmia ; and
in order to prevent this, so far as possible, it is important, not only
to improve the general health, but also to continue local treatment
until the eye is perfectly white on the child's awaking in the morning,
and even for fourteen days longer. This prolongation of the treat-
ment will also assist in clearing up opacities, as best they may be.
For this after-course of treatment calomel insufflations may be used.
In cases which do not readily yield to ordinary treatment tuberculin
or a staphylococcic vaccine should be tried.

Nothing can be done for the opaque scars left on the cornea
by ulcers when all inflammatory symptoms have subsided. If
the ulcer have been very superficial the resulting scar in young
children may disappear in course of time. Deep ulcers cause more
opaque and permanent scars, and ulcers which have perforated
produce the greatest opacity. Some of the very disfiguring scars
may be tattooed (chap. v.).

The degree of the defect of vision to which an opacity of the
cornea may give rise depends, in the first instance, on the position
of the opacity. If it be peripheral, the vision may be perfect ; but
if it be in the centre of the cornea, sight may be seriously damaged.
Even a slight nebula, barely visible to the observer, will cause serious
disturbance of vision if situated in the centre of the cornea ; while
in the same situation the very opaque scar of a deep ulcer will pro-
duce a proportionately greater defect. If a central, but not deep,
ulcer should not become completely filled up in healing, and a facet
remain, vision will also suffer much in consequence of irregular
refraction of the light which passes through the facet, even though
there may be but little opacity.

CHAPTER V.

DISEASES OF THE CORNEA.

The cornea is a clear membrane having a regular curvature and a
smooth surface which reflects objects without distortion, as long as
the epithelium and curvature are normal. It is non-vascular and
derives its nourishment by transudation from the vascular loops at
the limbus. Owing to its being overlapped by the conjunctiva to a
greater degree above and below than at the sides, it is usually oval
horizontally; measuring about 11 "5 mm. by 10"5 mm. Its thick-
ness at the circumference is only 1 mm. and less than that in the
centre. For clinical purposes it may be considered as consisting of
three layers — the surface epithelium, the proper substance of the
cornea, and Descemet's membrane, lining the posterior surface.
In examining the cornea the following points may require to be noted :
the size, shape (outline), degree of transparency, condition of
surface and sensibility.

Clinical Methods of Examining the Cornea.

1. By Diffuse Daylight. The patient is placed with his face
towards the window, and the cornea is carefully inspected while
he keeps both eyes open. His upper lid is then gently raised with
the surgeon's thumb, and he is called on to direct his eyes upwards,
downwards, to the right, and to the left, so that every part of the
affected cornea may be seen under the most favourable and varied
incidence of the light. Should there be much reflex blepharospasm,
the instillation of cocaine may be necessary. With small children
it is often necessary to adopt the plan illustrated by Figs. 34 and 35.

2, By Focal, or Oblique, Illumination. In the dark room the
light of the ophthalmoscope lamp is focussed with a + 14'0 D lens
on the cornea, which is thus seen brilliantly lighted up. The lamp
must be placed in front of, and slightly to the left-hand side, of the
patient, and about two feet from his eye. The lens is placed with its

110

CHAP, v.] THE CORNEA. Ill

principal axis in the direct line between the lamp and the eye, so
that the light may be concentrated on the cornea. By withdrawing
or approaching the lens a little, one can focus the light on the surface,
or in the substance of the cornea.

3. By the Combined Focal Method — that is focal illumination
as above, combined with the use, as a magnifying-glass, of a second
-f 14"0 lens. The second lens is held between the finger and thumb
of the left hand some inches from the patient's eye, while the surgeon
places his eye at the focus of this glass, the cornea being at the
same time illuminated by the light focussed on it with the other
lens held between the finger and thumb of the right hand, or, better
still, a binocular loupe may be used to magnify the cornea. Changes
in the cornea are then seen magnified, and at the same time highly
illuminated.

4. By the Ophthalmoscope with a + 18*0 or + 20*0 lens behind
the sight-hole of the mirror. The surgeon proceeds as though he
were about to examine the fundus in the erect image (p. 30). The
cornea is illuminated from the mirror, and changes in it are magnified
by the + lens through which it is inspected. Minute irregularities
of the surface or fine-dust-like deposits on Descemet's membrane
may be made out by this method.

5. By Fluorescine. In cases of ulcer, or any abrasion of the
corneal epithelium, when it is desired to ascertain accurately the
whole extent of the loss of substance, or if there be some doubt
as to the presence of such a lesion, an instillation of a drop of fluor-
escine solution (Fluorescin, gr. ij, Sodii Carb. gr. j, Aq. destill. 3 ij)
is used. About half a minute after the instillation the excess should
be washed away, when the whole region which is denuded of epithe-
lium will be seen stained of a greenish yellow colour. In some instances
where there is no true loss of substance, staining takes place if
the epithelium be not sound. An ulcer, which in the process of
healing has become covered with sound epithelium, will not stain,
although there may still remain some loss of substance to be filled
up. Fluorescine does not harm the cornea, nor interfere with healing
of any diseased process in it, and the staining disappears after a short
time. A pretty, and in some cases practically useful, method is v.
Keuss's double staining. After the lesion has been stained, as
above, with fluorescine, a drop of a 1 per cent, solution of methylene
blue (medicinal) is instilled, with the result that the general floor of

112 DISEASES OF THE EYE. [chap. v.

the lesion — i.e. the denuded corneal tissue — becomes blue, while the
margin — i.e. the loosened epithelium — remains of the greenish-
yellow colour.

The foregoing methods are in everyday use.

6. By the Corneal Microscope. This is an elaborate optical
instrument, which forms the outfit of a well-equipped ophthalmic
hospital, and is adapted for the minute study of diseased states
of the cornea and iris. It is not needed for ordinary clinical work,
and therefore a description of it will not be given here.

Inflammations of the Cornea.

From a clinical standpoint these inflammations will be most
conveniently considered under the headings — {a) Ulcerative In-
flammations, and (6) Non-ulcerative Inflammations.

(a) Ulcerative Inflammations of the Cornea. — Ulceration
of the cornea is preceded by a cellular infiltration , usually near the
anterior surface ; this keratitis is brought about, in most instances,
if not in all, by the entrance into the cornea — through the blood, or
through a traumatic loss of substance of the surface of the cornea —
— of certain micro-organisms : — pneumococci, diplobacilli of Morax,
staphylococci, streptococci, bacillus subtilis, etc. One recognises
the existence of an infiltration by seeing an opaque spot in the cornea,
with a dullness of the layers over it, and often also of the correspond-
ing part of the epithelium. Before long the epithelium covering the
infiltration undergoes necrosis and comes aw^ay, and soon the inter-
vening layers of the true cornea also break down, and in this way an
ulcer becomes established.

But although all ulcers of the cornea originate in an infiltration,
yet, once established, they assume great varieties of type, in con-
sequence, probably, of varieties in the nature of the originating
micro-organisms. Some ulcers are purulent, others non-purulent ;
some tend to spread over the surface of the cornea, others tend to
go deep into it ; the progress of some is very rapid, and of others
exceedingly chronic ; some attack by preference the central region
of the cornea, while others are confined to its margin ; some readily
give way to treatment, and others are very obstinate or even in-
curable. Again, some ulcerative corneal processes are attended
by much irritation : that is to say, circumcorneal injection, severe

CHAP, v.] THE CORNEA. 11.1

pain in and about the eye, great reflex blepharospasm, and lacrima-
tion ; whilst others, which may really be more severe processes in
so far as the integrity of the eye is concerned, can run their course
with hardly any injection of the eyeball, and with little or no distress
to the patient.

Etiologicalhj, corneal ulcers are primary or secondary. The
primary ulcers are those in which the diseased process originates
in the cornea, most commonly as the result of traumata, but also
in phlyctenular keratitis, or as the result of corneal abscess, or
w^here the nutrition of the cornea is interfered with, etc. Secondary
ulcers are those which are the result of disease elsewhere, usually
in the conjunctiva, as in acute blennorrhoea and in conjunctival
diphtheritis.

Corneal ulcers are more common in advanced than in early life.
Indeed, in early life, unless in cases of infantile ulceration with
conjunctival xerosis, of blennorrhoea neonatorum, and of phlyc-
tenular disease, corneal ulcers are almost unknown. The greater
liability to these affections in advanced life is due, it may be assumed,
to a less active nutrition at that period in this already lowly organised
part. Hence slight traumata, or the presence of a slight conjunctival
catarrh, which would have no ill effect in a young person, may form
the starting-point of a corneal ulcer in an old person, or even in one
of middle age. For the same reasons, corneal ulcers are much more
common in the poorer classes than amongst the well-to-do ; for
their general nutrition is often defective, while they are more exposed
to traumata than are the better classes.

The Diagnosis of the presence of a large corneal ulcer is simple.
Inspection of the cornea in ordinary daylight at once reveals the
loss of substance, more or less extensive, deep, or infiltrated. If
the ulcer be very small and shallow the difficulty is greater, especially
if there be much blepharospasm. An instillation of cocaine may be
necessary to facilitate the examination.

It is obviously important to decide at the outset, for the purposes
of prognosis and of treatment, whether a grey spot in the cornea
be a keratitis (a cellular infiltration which may shortly break down
and become an ulcer), an ulcer, or a scar (the result of an ulcer,
or other loss of substance). The surface covering an infiltration,
although flush with the general surface of the cornea, has usually
a steamy appearance, due to disorganisation of the corneal epithe-
8

14 DISEASES OF THE EYE. [chap, v

lium, and has no lustre. With an ulcer the appearances already
described will be found. The surface of a scar is usually, although
not always, flush with the general surface of the cornea, and it has
a bright surface — i.e. covered with normal epithelium, not rough,
irregular, nor even steamy. A scar, moreover, is generally more
defined at its edges, and is either pure white if opaque, or bluish
white if translucent. In cases of corneal infiltration, or ulceration,
there usually will be more or less pericorneal injection, pain, and
photophobia, while with a mere corneal scar there will be no irrita-
tion of the eye. Fluorescine stains an ulcer, and sometimes an
infiltration if it be near the surface, but not a cicatrix.

The presence of Hijfopyon {vtto, under ; ttvoi', pus) is the rule
with several types of corneal ulcer, notably the deep ulcer, and the
serpiginous ulcer. The term ' hypopyon ulcer,' Avhich is so much
used, should certainly be discarded, as hypopyon is not the charac-
teristic of one type of ulcer. Hypopyon is a deposit of pus in the
anterior chamber, and as the patient sits or stands it lies in the
lowest part of the chamber, to which place it has gravitated. If the
patient lie in bed, say on the side of the affected eye, the hypopyon
will of course change its position, and gravitate towards the temporal
side of the chamber. Sometimes the hypopyon is so small as to
be detected with difficulty ; and again it may fill the whole anterior
chamber, completely obscuring the iiis and rendering a diagnosis
of the condition of the cornea difficult. The pus cells in hypopyon
do not come from the ulcer, but are due to the presence of toxin in
the anterior chamber, which causes an exudation of polymorpho-
nuclear leucocytes from the vessels of the iris and ciliary body. These
cells are unable to make their way to the cornea owing to the mem-
brane of Descemet, and fall to the bottom of the anterior chamber.
The pus forming a hypopyon is sterile', unless, in the later stages,
the cornea be perforated.

The Dangers attendant upon Corneal Ulcers are, first of all, the
opacities, the scars, which even the slightest of them are apt to
leave behind.

Fig. 52 represents a section made through a deep ulcer in its
progressive stage. At the margin of the ulcer the epithelium (e)
and Bowman's membrane (b) cease. The floor of the ulcer is seen
covered with pus, which also infiltrates the corneal tissue beneath
the floor and around the margin. As soon as cure commences the

CHAP. V.J

THE CORNEA.

115

floor of the ulcer begins to clear, i.e. it becomes gradually less covered
with pus, until it is finally quite free from it, and 'pari passu the sur-
rounding infiltration of the cornea is absorbed. Then the epithe-
lium, growing in from the margin {m m, Fig. 53) all around, gradually

Fig. 52. {Fuchs.)

carpets over the floor of the ulcer, and underneath this newly formed
epithelium the new tissue, which is to close in the loss of substance, is
laid down. This new tissue, however, is not normal corneal tissue,
but is ordinary connective tissue, and is therefore opaque. Hence
the deeper the ulcer, the more intense will be the resulting
opacity. Bowman's membrane never becomes restored over the
cicatrix.

Fig. 53. (Fuchs.)

The ulcers which are situated at the centre of the cornea, in
the pupillary area, are more serious for sight than those situated
peripherally, as can be readily understood. The opacity left by
a very superficial ulcer is slight, and is called a nebula ; a somewhat

16 DISEASES OF THE EYE. [ohap. v.

more intense opacity is called a macula ; and a very marked white
scar is called a leucoma.

But a more serious danger connected with ulcers of the cornea
than the opacities they leave behind is that of perforation of the
cornea, to which some ulcers are very prone. The consequences
of perforation are : prolapse of iris resulting in anterior synechia^,
adherent leucoma, or staphyloma of the cornea, and fistula of the
cornea.

Treatment. — In the treatment of primary corneal ulcers the
student will soon observe that a bandage, atropine, and warm
fomentations play prominent parts ; and these routine measures
alone are sufficient to produce cure in the less severe cases.

The bandage should be put on w4th firm pressure — but should
not be made uncomfortably tight — the eye having been previously
padded out, especially at the inner canthus, so that equal pressure
may be exercised all over the globe. The support thus given to
the cornea and front of the eye promotes the healing process, and
the bandage is also useful by preventing the eyelids from rubbing
over the ulcer, and by protecting it from foreign bodies. In those
secondary ulcers, which are due to conjunctival processes, such as
catarrhal conjunctivitis or blennorrhoea, a bandage is contra-
indicated, because it retains the secretion, and would therefore do
harm rather than good.

Atropine in sufficient quantities to keep the pupil dilated should
be employed. Iritis very often attends severe corneal ulcers, and
here the indication for atropine is obvious. But rest of the affected
part is, we know, an important element in preventing or in curing
any inflammation ; and in the affections we are now treating of,
even if there be no iritis, atropine acts by procuring rest of the
iris and of the ciliary muscle.

Miotics are preferred by some to mydriatics in the treatment
of corneal ulcers, on the ground that the action of miotics in reducing
the intra-ocular tension promotes healing, and that the more ex-
tended surface of iris — more extended absorbing surface — facilitates
absorption of hypopyon. It is not certain that miotics do reduce
the normal tension, and in these cases they undoubtedly increase
the tendency to iritis. As to absorption of the hypopyon, it will
come about in due course when the cornea begins to recover. Yet
a clear indication for miotics is given by the presence of an ulcer

CHAP, v.l THE CORNEA.

near the corneal margin, which has a tendency to perforate, for
here the miosis would assist in preventing prolapse of the iris,
should perforation take place.

Dionine is useful in the treatment of many cases of primary
corneal ulceration and other primary corneal diseases. Its physio-
logical action is to cause dilatation of the blood vessels of the con-
junctiva with great chemosis — although it does not act equally
well in every eye — and its therapeutic effect is held to depend on
this lymphatic flooding of the front of the eye. It is used in a
5 per cent, solution dropped into the eye once a day, but stronger
solutions or even the powder itself may be applied by the surgeon
if necessary. If employed frequently it ceases to produce any
reaction, and for this reason it may be desirable in some cases to
use it once only on alternate days. It causes slight ansethesia of
the cornea.

Warm fomentations promote the healing process by stimulating
tissue-changes in the cornea. One usually orders them to be made
with poppy-head water or camomile tea, although no doubt warm
sterilised water would be equally efficacious. Hot solutions of
4 per cent, boric aid, or 1 in 5000 corrosive sublimate, may be used
with advantage. A compress of cotton wool which has been dipped
in the stupe at about 120° Fahr. is laid upon the eye, and frequently
replaced by fresh compresses out of the stupe, so that the compress
on the eye may always be hot. This is continued for half an hour
at a time, and repeated every two or three hours. Or, the Japanese
muff-warmer, or a special electric warmer, may be applied.

In an ulcer of a purulent or sloughing nature, the insuffiation
on its floor of very finely divided xeroform or iodoform powder is
useful. A purulent ulcer may be cleansed with hydrogen peroxide,
or touched with pure carbolic acid, tincture of iodine, or 20 per cent,
sulphate of zinc. A quinine derivate, ethyl hydrocuprein (optochin)
in 1 per cent, solution is especially useful in pneumococcus ulcers.
Scarlet-red ointment (1 in 20) we have also seen do good.

When more active measures than the foregoing are called for,
the actual cautery, curetting, paracentesis, and subconjunctival
injections of oxycyanide of mercury (5 min. of a 1 in 5000 solution)
have to be resorted to.

The actual cautery is much in use in the treatment of serpiginous
and other infected corneal ulcers. It acts by destroying the micro-

DISEASES OF THE EYE.

[chap. v.

t.^

organisms, which keep the process going. Either a thermo-cautere,
in the form of a very fine point, or the galvano-cautery (Fig. 54),
the platinum wire being at a red-heat, may be employed. The eye
having been cocainised, the red-hot point is
brought into contact with the whole surface of
the ulcer, so as to thoroughly destroy its super-
ficial layer, and special attention is given to any
part of the margin of the ulcer where there is a
tendency to spread to as yet healthy tissue.
Fluorescine may be used to show the exact ex-
tent of the ulcerated surface. The cauterisation
can be repeated as often as the state of the ulcer
may make it desirable. It is sometimes well to
perforate the cornea with the cautery, and to
evacuate the aqueous humour and hypopyon ; or
this may be done with an ordinary paracentesis
needle, after the cauterisation is completed. The
cautery gives a good percentage of cures with the
least amount of opacity.

Thorough curetting of the floor of the ulcer
with a small sharp spoon is a valuable method,
either alone or prior to cauterisation.

Paracentesis of the anterior chamber through
the floor of the ulcer is another most valuable
therapeutic measure for some corneal ulcers, and
deserves a more routine application in these cases
than is accorded to it ; the more so as the little
operation is simple and dangerless. But there are
two indications for its use which should be re-
garded as imperative — namely, (1) If there be
great pain. 8oon after the operation, which for a
short time increases the neuralgia, the patient ex-
periences great relief, and passes the first good
night after many wakeful ones. (2) If perforation

Fig. 54. — The bolt B being pushed forwards, the

circuit is completed. By pressure on the button A the

current can be momentarily intercepted during use of

the instrument. There are other good patterns of

Fig. 54. galvano-cautery.

CHAP, v.] THE CORNEA. 119

seem to be imminent. This may often be recognised by a bulging
forwards of the thin floor of the ulcer ; but sometimes it is not
easily foreseen, and if there be any doubt on the point, paracentesis
should be performed. It is important to forestall spontaneous
perforation of the ulcer by this proceeding, because the opening
that is made, being linear, heals easily, and leaves but a slight scar
without anterior synechioe ; while the natural opening
would be a complete loss of substance, and would, there-
fore, the more readily involve adhesion of the iris in the
resulting, and comparatively extensive, cicatrix. Other
indications for the operation are increased tension, and
the presence of a large hypopyon.

Paracentesis of the anterior chamber is best performed
by means of a paracentesis needle (Fig. 55), which is a
small somewhat shovel-shaped blade. If this be not at
hand, a small keratome, or a broad needle, or a Grsefe's
cataract knife will answer the purpose. The eye having
been cocainised, a spring lid-speculum is inserted, the
conjunctiva near the cornea is grasped with a fixation
forceps,^ if necessary, and the point of the paracentesis
needle applied to the floor of the ulcer, in such a way that
the plane of the little blade may be at an angle of about
45° with that of the floor of the ulcer. The point is pushed
gently through the floor, and the plane of the blade is then
immediately changed, so that, as the instrument is being
advanced up to the hilt, it may be almost in contact with
the posterior surface of the cornea. The instrument should
be withdrawn very slowly, in order that the aqueous
humour may flow oii gradually, and not with a rush. If
these precautions be taken, there need be no danger of
injury to the crystalline lens, or of prolapse of the iris into ^^^^
the incision. Should prolapse occur, it can usually be re-
posed with the spatula. It may happen that when the needle has
been withdrawn a considerable portion of the aqueous humour may
remain in the anterior chamber, unable to escape owing to the
valve-like closure of the wound. It should be evacuated by making

1 If the eye be much congested and very painful, a few ch-ops of cocaine
can be injected subconjunctivally at the point where it is intended to
apply the fixation forceps.

120 DISEASES OF THE EYE. [chap. v.

the wound gape by gentle pressure with a spatula on its posterior
lip. If it be desirable to tap the anterior chamber on the
next day, this can be done by simply opening up the wound
with a spatula, or with the probe-like instrument at the other
end of the handle (Fig. 55), without the aid of any cutting in-
strument.

Subconjunctival injections of solution of oxycyanate of mercury
(1 in 5000) or of solution of chloride of sodium (4 per cent.) enter
largely into the therapeutics of corneal disease, and of disease in
the uveal tract. It makes the little operation much less disagreeable
for the patient if a speculum and forceps be dispensed with. With a
sharp needle there is no difficulty in thrusting the point under the
conjunctiva. It should be entered near the fornix, certainly not
close to the cornea. It is not necessary that the injections should be
made under the capsule of Tenon as was at first supposed. The
mode of action of these injections is not clearly understood. It is
not due to the entrance of the preparations into the tissue of the
cornea or interior of the eye, for only minimal quantities of even
mercurial salts have been found in the vitreous humour. It was
at first believed that they acted as lymphagogues, but their curative
power is now held to depend on the vascular reaction to which they
give rise. Of the oxycyanate of mercury solution 5 to 10 minims
according as it can be borne, or of the saline solution 10 to 20
minims, are injected under the bulbar conjunctiva in the direction
away from the cornea. Other solutions (sublimate, hetol, cyanate
of mercury, iodipin, iodide of potash, etc.) have been employed,
but these two are as efficacious as any. From 2 to 5 minims of a
1 per cent, solution of acoine may be taken up in the syringe with
the main solution, just before the injection is made, in order to
diminish the severe pain and irritation which come on afterwards,
and last often for several hours. This pain may be much relieved
by hot fomentations, but if it be very intense a hypodermic injection
of morphia may be necessary. Or, if one or two drops of a 4 per
cent, solution of dionine be instilled into the eye, followed a few
minutes later by an instillation of a 4 per cent, solution of cocaine,
a subconjunctival saline injection may be made almost painlessly.
Considerable vascular injection and chemosis may be present next
day, and the eyelids may be swollen and oedematous. The injection
should not be repeated until the redness and oedema have almost

THE CORNEA. 121

subsided. Few eyes require, or can tolerate, more than two in-
jections in the week. (See also chap, xi.)

If the case do not come under the care of the surgeon until
perforation of the ulcer with prolapse of the iris has taken place,
the important question as to the best method of dealing with the
condition is presented. If the loss of substance should occupy one
third or more of the cornea with correspondingly large prolapse
of iris, the development of a staphyloma is almost inevitable.
Eserine is to be used to reduce the intra-ocular pressure, and a firm
bandage is to be kept applied to the eye. And here transplantation
of conjunctiva over the ulcer and prolapsed iris, to strengthen the
cicatrix (see below), is indicated. But if the ulcer and prolapse be
small, an attempt may be made to free the iris, so that no anterior
synechia may form, and in order that the cicatrix may be flat,
and not raised over the surface of the cornea, and, consequently,
exposed to injury. The importance of such an attempt lies in the
fact that a corneal cicatrix with iris entangled in it — not merely
adherent to its posterior surface — affords a constant source of
danger, especially if situated near the margin of the cornea ; for
in such eyes, it may be years later, sudden and uncontrollable
purulent inflammation of the iris and chorioid may come on from
septic infection, after an apparently slight trauma of the cicatrix,
and may rapidly end in total destruction of the eye. The surgeon's
attention should therefore be directed to obtain at least as flat a
cicatrix as possible, or, still better, a non-adherent cicatrix. The
practice which is commonly follow^ed, is to draw the freshly pro-
lapsed portion of iris slightly forwards with a forceps, and to snip
it ofi level with the surface of the cornea ; and then with a spatula
to endeavour to free the iris from any adhesions it may have formed
with the margin of the ulcer. Atropine or eserine, according to the
position of the ulcer, is then instilled, and a bandage carefully
applied. This proceeding is only of use when a fresh prolapse
can be dealt with, before cicatrisation sets in ; and the result is
often satisfactory in so far as the securing of a flat cicatrix is con-
cerned, but an anterior synechia can rarely be avoided.

Kuhnt's method for strengthening the cicatrix, where an exten-
sive ulceration with prolapse is present, by means of a conjunctival
flap, with single or double pedicle, which is drawn over the ulcer,
is aValuable_one. If, for example, the ulcer and prolapse be at a

122

DISEASES OF THE EYE.

[chap. v.

(Fig. 56), an incision 6 c is made through the conjunctiva along
the margin of the cornea, and an incision d e more peripherally,
or it is perhaps better to make the peripheral incision first. The
flap so outlined is dissected up, drawn over the cornea, ulcer, and
prolapse of iris, and then secured in its new position by means of
a suture (/, Fig. 57). In forming the conjunctival flap, care should
be taken to obtain it with as little subconjunctival tissue adherent
to it as possible. In a few days the flap becomes adherent to the
ulcer and prolapse, and its upper and lower positions can then be
released with the scissors. By this means a stronger covering
for the ulcer and prolapse is provided, and the dangers of late
infection and of staphyloma are minimised. A flap with a single

Fig. 50.

Fig. 57.

pedicle may also be used, or the conjunctiva may be loosened at the
limbus and drawn over the ulcer by sutures above and below, or
even made to cover the whole cornea by a purse- string suture.

Different types of corneal ulcers are recognised and described.
Of these the following are the chief :—

Simple Ulcer. — This may result from a slight trauma, or it may
originate in a phlyctenula. It presents the appearance on the
surface of the cornea of a minute and shallow^ depression w^ith a
grey floor. There is circumcorneal vascularity, especially at that
part of the corneal margin nearest to which the ulcer is situated ;
the pupil is apt to be contracted, although iritis is not present,
and there is often a good deal of pain, lacrimation, and photophobia.

Treatment and Prognosis. — The eye is to be bandaged, warm
fomentations applied several times a day, and a drop of solution

CHAP, v.] THE CORNEA. 123

of atropine instilled night and morning. When of phlyctenular
origin, stimulation with the yellow oxide ointment is indicated.
Dionine may be used. Cure, with slight opacity remaining, comes
about in a week or ten days. But, if it become infected, this form
of ulcer may pass over to the deep ulcer.

Deep Ulcer. — This is a septic or infected ulcer, and commences
in a septic infiltration of the cornea. It forms a tolerably deep pit
in the cornea towards its centre, the floor of the ulcer being covered
with purulent deposit and detritus, and the corneal tissue imme-
diately surrounding it being somewhat infiltrated with pus. The
ulcer is generally round, but it may assume any shape. Hypopyon
is often present, and a marked tendency to iritis exists. The pain
is usually very severe, violent frontal neuralgia being a common
symptom.

This ulcer has no great tendency to spread over the surface of
the cornea, but has a very decided tendency to perforate through
it. As it does not generally attain w^ide dimensions, the perforation
it may produce is small, and gives rise to a small adherent leucoma
rather than to a staphyloma. It seldom causes complete loss of
the eye.

Causes. — This form of ulcer is a frequent one in gonorrhoeal
ophthalmia and in blennorrhoea neonatorum ; and it may be caused
by the lodgment of foreign bodies, and other injuries of the cornea.

Treatment. — If the ulcer be due to a conjunctival process, the
latter should be actively treated, and the only attention needed for
the ulcer is to anticipate by paracentesis a spontaneous perforation.

If the cause be other than conjunctival, a pressure bandage
to give support to the ulcer is important, and periodical w^arm
fomentations are most beneficial ; but where the cause is con-
junctival (purulent conjunctivitis), neither a bandage nor warm
fomentations can be used. Atropine should be instilled in all cases
several times daily, and antiseptic applications, especially xeroform,
are useful.

Paracentesis through the floor of the ulcer is always followed by
improvement, and is important as a preventive of natural perforation.
The actual cautery may be necessary.

Fistula of the Cornea. — The deep ulcer when it perforates is
the most common cause of fistula of the cornea. A fistula presents
the appearance of a very small black spot near the centre of a

124 DISEASES OF THE EYE. [chap. v.

leucoma, and is liable to form when the perforating ulcer is in the
pupillary area of the cornea, so that it cannot be perfectly closed
by the prolapse of iris into it. In this position the ulcer closes
by the slow growth of connective tissue from its margins, and
sometimes this process does not go on to completion, and a small
central fistula is left. Or, the perforation is so situated, that just
a small tag of the pupillary margin of the iris is incarcerated in the
cicatrix ; and the pulling of the iris on this, as the pupil dilates,
prevents complete closure of the orifice. Or, if the perforation be
of wide area, with extensive iris-prolapse, the pressure of aqueous
humour may cause a small rupture in the prolapse which may
not heal again. Through the fistula, however, it may occur, aqueous
humour constantly trickles away, the anterior chamber remains very
shallow or quite empty, the globe is soft, and gradually becomes
softer ; or, the fistula closes for a time, the eye then becoming of
glaucomatous hardness, and the high tension luptures the cicatrix,
which again closes, and is again ruptured by high tension. Finally,
sight is lost through secondary glaucoma, detachment of the retina,
or severe uveitis or haemorrhage.

Fistula of the cornea is very difficult of cure. The treatment
consists in the use of a myotic to keep the intra-ocular tension low.
With the same object an iridectomy is indicated, but is difficult
of performance owing to the shallow anterior chamber. An iri-
dectomy may also be indicated to withdraw a tag of the margin
of the pupil, which may be engaged in the fistula. The margins of
the fistula may be curetted, or cut away, or cauterised, but the
close proximity of the lens must be borne in mind, lest its capsule
be mjured by these proceedings. After curetting, a conjunctival
flap with pedicle may be transplanted over the opening (p. 122) ;
the flap by healing to the curetted margin aids in the closure of
the fistula. Or, into the opening, the margins of which have been
previously curetted, a small' flap of conjunctiva without pedicle
may be pushed, which, healing in it, closes the opening.

Serpiginous Ulcer (Pneumococcus Ulcer, Ssemisch's Ulcer). —
This is a purulent ulcer, with a characteristic tendency to creep
over the surface of the cornea, especially in some one direction,
rather than to strike deep into its tissue. It originates in a superficial
infiltration or abscess, wliich rapidly ulcerates. Its position is chiefly
central, and it presents a greyish floor, which is more intensely

CH.\p. v.] THE CORNEA. 125

opaque at some places. One part of the margin takes the form of a
curve, or of several closely placed curves, and becomes there yellow-
ish white in colour and somewhat raised, and the floor of the ulcer
seems deeper in its neighbourhood. Immediately around the ulcer
the cornea is slightly opaque, but farther out it is normal.

The pain and irritation vary much in degree, being almost
absent in some cases, while in others they are intense. Iritis is
apt to come on at an early period, and may pass into irido-cyclitis.
Hypopyon is almost always present. On the posterior surface of the
cornea, from the region corresponding with the ulcer on the anterior
surface, a line of pus is sometimes seen extending down to the
hypopyon, and this was formerly taken as a proof that the hypopyon
was formed by direct transmission of the pus corpuscles through
the cornea from the ulcer. The ulcer creeps over the surface of
the cornea in the direction of the curved and more intensely infil-
trated portion of the margin — the progressive margin — while the
opposite side of the margin tends to become cleaner. At a still
later stage the whole cornea is apt to become infiltrated, and the
entire margin of the ulcer to extend, and the anterior chamber
becomes quite full of pus. Perforation now takes place, or may
do so somewhat earlier. If the perforation be small, an adherent
leucoma results ; but if large, a staphyloma of the cornea gradually
develops, or panophthalmitis may immediately follow on the
perforation.

Causes. — Ulcus Serpens always has its origin in a trauma, which
has produced, it may be, only an abrasion. In perhaps 50 per
cent, of the cases chronic dacryocystitis is present, and in about 25
per cent, more there is ozoena, and a considerable proportion of them
occur in the warm summer months. It is a disease of the poorer
classes, is seldom seen in children, is most common between the
ages of forty and seventy, and is more common in men than in
women.

In most instances the pneumococcus — which is usually present
in the discharge in chronic dacryocystitis — is the excitant of the
typical ulcus serpens, but occasionally cases have been observed in
which the pneumococcus was not present, and the diplobacillus
liquefaciens, the streptococcus, the bacillus subtilis, or some rarer
form of micro-organism, was the excitant.

Prognosis. — From the description given, it will be seen that the

126 DISEASES OF THE EYE. [chap. v.

process is a severe one in very many cases, and tlie prognosis for
vision, or it may even be for retention of the eyeball, very serious.
Yet cases of a mild type do occur which soon give way to ordinary
routine treatment, and leave only a relatively small and not very
opaque, but centrally situated, corneal cicatrix, allowing of some
useful vision, which may be improved by an optical iridectomy.
Again, the prognosis depends very much upon the stage at which
the case comes under treatment. The process can frequently be
arrested at an early stage, while later it will resist every treatment,
and will lead on to panophthalmitis, or extensive leucoma.

Treatment.— li the case be not severe, atropine, with protection
of the eye, may cure in a few days, but it is not wise even in the
apparently mild cases to trust to these measures. Warm fomenta-
tions should not be used, as they rather promote the activity of
the diseased process ; and the eye should not be bandaged, lest
infective discharge be retained in the conjunctival sac. Antiseptic
measures should always be employed from the beginning, a very
good one being the thorough, but localised, application of pure
carbolic acid, which can be conveniently applied with a pointed bit
of stick such as a w^ooden match trimmed to a point. Ethyl hydro-
cuprein exerts a specific action in pneumococcal ulcers ; it may be
used in 1 per cent, solution dropped in frequently during the. day,
or a small bit of lint saturated in the solution may be applied directly
to the ulcerated surface for a few minutes. We have also applied
the powder itself. The floor of the ulcer may be washed with a
solution of sublimate 1 in 5000, or with hydrogen peroxide, or
other antiseptic solutions.

But it is in all respects wiser to deal with these cases, even the
apparently mild ones, actively, as soon as the case comes under
observation, and in anticipation of the time, which approaches
rapidly, w^hen treatment cannot be of any practical avail. If, as is
so often the case, chronic dacryocystitis be present, the lacrimal sac
should at once be extirpated {vide chap. xix.). At the same time
one or other of the following local measures should be employed —
the first is suitable to cases in which the infiltration is still confined
to the superficial layers, where the products of disease can all be
reached by the cautery ; while the second is indicated in cases in
which the deep parts of the cornea have become involved.

1. The Actual Cautery at a red heat is a valuable method of

OHAP. v.] THE CORNEA

treatment for this ulcer iji the early stages. It is the infiltrated
and undermined margin of the ulcer which should be most thoroughly
cauterised ; but its floor, if much infiltrated, is also to be dealt
with. The application of fluorescine just before the use of the
cautery is valuable, as it enables the operator to discern clearly the
whole of the diseased part requiring cauterisation. Even the
cautery is often ineffectual to arrest the progress of the ulceration.

At the thinnest part of the floor of an extensive serpiginous
ulcer it is desirable to make a perforation through the cornea with
the point of the cautery ; or, when the cauterisation is finished,
the cornea may be paracentesed with a broad needle in a sound
region beyond the ulcer. The object is to reduce the intra-ocular
tension, and thus promote the nutrition of the cornea. Of late
some surgeons have used with advantage, instead of the cautery,
hot air projected in a stream on the ulcer, say with a rubber balloon
as used by dentists ; or the ulcer is touched with a metallic pointed
tube heated by hot air or alcohol vapour (Wessely).

Subconjunctival injections of a 1 in 5000 solution of cyanide
of mercury, or of a 4 per cent, saline solution assist the cure (p. 120).

2. Ssemisch's Method consists in division (Keratotomy) of the
ulcer with a Grsefe's cataract knife. Cocaine having been applied,
the point of the instrument is entered about 2 mm. from the margin
of the ulcer in the healthy corneal tissue, and, having been passed
through the anterior chamber behind the ulcer, the counter-puncture
is made in the healthy cornea some 2 mm. from the opposite margin
of the ulcer. The edge of the knife being then turned forwards,
the section is slowdy completed. The incision should divide the
intensely infiltrated part of the margin in halves. The aqueous
humour and hypopyon are evacuated, atropine is instilled, a bandage
is applied, and the patient soon gets relief from pain. Every day,
until healing of the ulcer is well established, the wound must be
opened up from end to end with the point of a fine probe or spatula,
the contents of the anterior chamber being thoroughly evacuated
on each occasion, and atropine instilled. The result is that, in
many cases, the progress of the ulcer is arrested, and healing sets
in. The operation may be employed with advantage even in late
stages of the process.

Komer has proposed, and both he and some others have carried
out treatment of the serpiginous ulcer with an anti-pneumococcus

128 DISEASES OF THE EYE. [cHAr. v.

serum. The treatment is rational, but it should be employed
early ; and alone it is hardly sufficiently rapid in its action to
be relied upon in these quickly destructive cases.

* Marginal Ring Ulcer appears as a clean-cut, or but slightly
infiltrated, yet rather deep, ulcer just inside the limbus of the cornea.
Its tendency is to extend along the margin of the cornea ; and in
some instances healing takes place in the older parts of the ulcer,
while it is still progressive at the newer parts. It may extend all
round the cornea, and finally give rise to complete sloughing of the
latter by cutting off its nutrition. This ulcer may result in children
from a marginal phlyctenular infiltration, but is more common in
adults, or in aged people, whose nutrition has fallen very low.

Treatment. — The actual cautery, silver nitrate. If necessary,
paracentesis through the ulcer, eserine having been first instilled.
Insufflation of xeroform. Warm fomentations. A dressing and ban-
dage. Quinine, iron, and strychnine internally, with nutritious diet.

Diplobacillus Ulcer. — This ulcer, which is not very common, bears
some clinical resemblance to the ulcus serpens, and may be mistaken for
it ; but it is associated with very little pain or irritation, is less destructive,
slower in its progress, and more amenable to treatment. Catarrhal con-
junctivitis (p. 55) is often present, while dacryocystitis is absent. The
history of a trauma is commonly to be obtained. The definite diagnosis
can only be made by a bacteriological examination of the secretion taken
from the floor of the ulcer, in which the diplobacillus (Moiax-Axenfeld)
(p. 51) or the diplobacillus liquefaciens (Petit) should be found. In the
initial stage, a central, or almost central, grey infiltration, often of very
small size, appears near the surface of the cornea, surrounded by a delicate
halo of less intense infiltration, and there is marked pericorneal injection.
After a few days the ulcer becomes developed. It is 2 to 4 mm. wide,
shallow, and covered with a greyish membranous exudation, which can be
lifted off. Occasionally the floor is greyish-yellow, and deep. The margin
is often slightly raised, and sometimes undermined. The superficial layers
of the cornea around the ulcer are somewhat opaque, with stippling of the
epithelium overlying them ; and, deeper in the cornea, radiating grey
striae reach into the healthy cornea, of. en nearly to its margin. Hypopyon
is usually present. The severity of the corneal process in the later stages
often alters the character of the conjunctivitis, when any is present, so
that it can no longer be recognised as catarrhal. Occasionally small out-
lying infiltrations form in the cornea. The ulcer increases in size by exten-
sion of its margin in all directions, although in some cases this process,
as in ulcus serpens, is mainly in some one direction. Only in the severest
cases do infiltrations form in the deep layers of the cornea. A neglected
case may lead to destruction of the eye through panophthalmitis, but
careful treatment will save most of these eyes.

CHAP, v.] THE CORNEA. 129

Treatment. — Sulphate of zinc is practically a specific for the ciu-e
of these ulcers. To effect a satisfactory result in a severe case it is neces-
sary that the applications should be made with frequency, regularity, and
thoroughness. A solution of sulphate of zinc of 1 per cent, should be
dropped into the eye once every hour, or even more frequently ; and in the
intervals an ointment consisting of ichthyol TS per cent., and zinc sulphate
\ per cent., is inserted into the conjunctival sac. The ulcer may be
touched with a cotton wool pencil soaked in the solution, and compresses
saturated with the solution may be laid on the eye at intervals for twenty
minutes. The treatment is often required to be continued for two or three
weeks, or more. In rare cases the galvano-cautery, or Ssemisch's operation
may be needed. Curetting is not advisable. The zinc treatment is in
no way injurious to the eye, although temporarily deposits of the salt on
the ulcer do sometimes occur. The opacities left by a diplobacillus ulcer
of the cornea are, in time, capable of much clearing.

Rodent Ulcer (Mooren's Ulcer). — This is a rare and extremely dangerous
form of ulcer of the cornea, and must not be confounded with the
serpiginous ulcer. It is not a purulent ulcer.

The disease commences as a small — sometimes even pinhead sized —
grey infiltration near the corneal margin, not differing in appearance from
many a harmless catarrhal infiltration. This rapidly ulcerates. Other
similar infiltrations appear in the neighbourhood and at other parts of the
margin, and ulcerate, and the ulcers coalesce into one, of which the advanc-
ing margin nearest the centre of the cornea is undermined. The under-
mined margin, under which a fuie probe can be inserted, consists of partially
necrosed corneal tissue, and presents the appearance of a narrow whitish
line overhanging the line of active disease. The cornea beyond the
margin of the ulcer is normal. The eyeball is injected. The ulcer does
not go deeper than about one-fourth of the thickness of the cornea, and
perforation seldom occurs. Occasionally a very small hypopyon is
present, and occasionally too there is iritis. There is very great pain and
photophobia in some cases, and in others hardly any.

Before long the ulcer in its oldest portion begins to be vascularised
and to heal, and finally leaves an intense cicatrix behind. Gradually
the ulceration creeps round the cornea, and at the same time advances
towards its centre, by small infiltrations appearing just inside the opaque
margin, which coalesce and soon break down, while healing is taking place
in the oldest portions of the ulcer. This process goes on until, finally, the
whole siirface of the cornea has been eaten away, and cicatricial tissue
substituted for it, its centre being the last place affected, and then vision
will have become reduced to finger-counting or \ o perception of light.

The progress of the disease is very slow, many weeks or even some
months often elapsing before the surface of the whole cornea has been
destroyed, and the ulceration may become stationary for a time, only to
start afresh without any apparent reason. Some clearing up of the cor-
neal opacity may subsequently take place, but cannot be reckoned upon.
Yet in a few cases, by gradual clearing of the cornea, fairly good vision
has been regained in the course of a year or two. The disease attacks
both eyes in about one-fourth of the cases, although there may be an

130 DISEASES OF THE EYE. [chap. v.

interval between the onset in each, of weeks, or months, or more. It
attacks decrepit people of over middle life, but occurs also in young persons
and in those of apparently robust health. Its etiology is obscure. No
specific micro-organism has as yet been discovered as the immediate cause.

The onset at the edge of the cornea in the form of small grey infiltra-
tions, the grey and shallow floor of the ulcer, its pale grey or almost white
margin, the undermining of this margin (which may readily be ascertained
by passing the point of a probe under it), and the steady advance of the
ulceration towards the centre and around the edge of the cornea, are the
characteristics of this disease.

Treatment. — Rodent ulcer is usually a most intractable disease, no
reliable method of treatment, to which the majority of cases will respond,
having been as yet put forward.

The general nutrition of the individual is to be improved, but reliance
is mainly to be placed on local treatment, which should especially be
directed to the undermined margin, or rather to the surface immediately
underlying this, after the overhanging lip has l:een cut away with fine
sharp scissors.

The galvano-cautery is much in use here, and it is important that
the burning should be rather deep. Pure liquid carbolic acid applied
with a fine bit of wood, the excess being taken up with a bit of blotting
paper, is also useful. In a case under our care absolute alcohol
applied to the ulcer (p. 134) produced a remarkable and rapid ciire, so
that a small central area of sound cornea was preserved ; and a second
case has been similarly cured. Curetting, tinctiare of iodine applied with
a camel's-hair pencil, sublimate lotion, with a bandage and the usual warm
fomentations, may help in the treatment. The covering of the diseased
part — after it has been well cauterised — or of the entire cornea, with a
conjunctival flap, is worth the trial.

Keratomalacia (Infantile Ulceration of ths Cornea with Xe osis of the
Conjunctiva) is a very rare affection. It attacks some poorly nourished
children early in the first year of life, making its appearance at or near
the centre of the cornea. Iritis always supervenes in severe cases. That
portion of the bulbar conjunctiva which is exposed in the palpebral aper-
ture at either side of the cornea undergoes slight epithelial xerosis, similar
to that in functional night blindness, due to retinal exhaustion. Some-
times the xerosis of the conjunctiva is absent. Ulceration of the cornea
soon comes on, tlirough necrosis of the layers lying over an interstitial
infiltration ; and this ulceration spreads until it involves the whole of the
cornea, except a very narrow margin. Finally, perforation, with prolapse
of the iris, and panophthalmitis may supervene. The accompanying
symptoms, ciliary congestion, photophobia, etc., are, strange to say, very
slightly marked.

Both eyes become affected as a rule, altliough the disease usually
attacks one eye some time before its fellow. The patients almost always
die of diarrhoea, pneumonia, etc.

Cause. — Streptococci have been found in the corneal ulcer and in the
conjunctiva, while a general streptococcus invasion of the vascular system
of the whole body is also present. To the latter circumstance are referred

CHAP, v.] THE CORNEA. 131

the conditions which lead to a fatal termination ; but in some cases the
pneumococcus alone was found. Many of the infants attacked are syphi-
litic, and spirochaete have been found in the cornea (Stephenson), but
whether, as is held by some, the corneal process is a specific one, and not
merely part of the general cachexia, is an open question.

Treatment is generally of little avail ; but warm fomentations, the
use of non-irritating antiseptic lotions, and the usual treatment for puru-
lent affections of the cornea should be tried. Such means as may possibly
promote improvement of the general system are obviously called for, and
in cases of congenital syphilis, calomel internally or mercurial inunctions.

Neuro-ParalytiC Keratitis. — In paralysis of the Ophthalmic Division of
the Fifth Nerve purulent infiltration and ulceration of the cornea with
hypopyon are occasionally observed, or the process inay be very superficial
and aseptic. It was formerly believed that the fifth nerve had an influence
over the nutrition of the cornea, and hence that neuro-paralytic keratitis
is a trophic process ; but an analysis of the recorded cases shows that the
keratitis occurs only in' irritative lesions of the fifth nerve, and that the
development of the affection is assisted by the diminished reflex lid-action
and secretion of tears, and consequent drying and disorganisation of the
corneal epithelium, which renders it possible even for septic infection of
the cornea to take place. This disease, therefore, cannot be regarded as
of neuropathic origin in the strict sense of the term.

That keratitis is not very common with paralysis of the fifth nerve is
doubtless due to the moisture of the surface of the cornea being sufficiently
maintained through the consensual action of the eyelids of the affected eye
with those of the opposite eye ; and, also, that reflex lacrimation of the
affected eye, although in diminished degree, results from stimulation of
the opposite cornea. Yet under certain conditions — e.g. if the nictitation
be incomplete (partial paralysis of the facial nerve), or if there be some
proptosis — the cornea may become dry, and keratitis may appear. In all
the cases published of paralysis of both fifth nerves, keratitis appeared,
for here the protection of the reflexes originating on the other side was not
present. The absence of any ill-result to the cornea from the operation of
extirpation of the gasserian ganglion on one side only for severe neuralgia
is explained by what has just been stated.

The surface of the anaesthetic cornea becomes dull over a central cloudy
area, and this is soon followed by a superficial erosion. The ulcer may
become purulent, and may end in panophthalmitis, or it may heal up,
leaving a central opacity. In some cases the eye becomes soft and more
or less shrunken.

The commonest causes of neuro-paralytic keratitis are intra-cranial
tumours and fractures of the skull.

Treatment consists, in the milder cases, in protection of the cornea by
keeping the eyelids closed with a bandage, or by fastening them together
with a dermic suture. The severer cases of purulent infiltration or ulcera-
tion must, in addition, be dealt with on the lines laid down in previous
pages for the treatment of those conditions.

Herpes Corneae Febrilis.— Not only in herpes zoster ophthalmicus

132 DISEASES OF THE EYE. [chap. V.

(chap, xviii.), but also in herpes febrilis (or catarrhalis) is a vesicular
eruption liable to occur on the cornea. It is met with in any of the
inflammatory affections of the respiratory tract, from a common cold
to severe pneumonia, and may be associated with herpetic eruptions
on the lips. It also occurs with whooping cough, and with inter-
mittent and typhoid fever ; but it may be a primary affection.
It is probably more common than ophthalmic practice would lead us
to think, for it is the resulting ulceration which usually comes under
our notice. The patient complains of the sensation of a foreign
body in the eye, with lacrimation and photophobia, and these
symptoms disappear w^hen the vesicles rupture.

On the surface of the cornea of one eye is formed a grouj) of
clear vesicles, each from 0*5 to 1*0 mm. in diameter. They usually
form in a line, which runs obliquely across the cornea, or sometimes
in a vertical direction. Now and then they are arranged in trefoil
shape or in a circle. The covering of the vesicles is short-lived,
and, as already remarked, the resulting ulcer is that which the
surgeon usually first sees. Even it, however, is thoroughly
characteristic. On the surface of the clear cornea is an irregular
loss of epithelium, along the margins of which may still sometimes
be seen the shreds of the late covering of the vesicle. The margin
of the region which is bared of its epithelium is dentated, and can
only be mistaken for a traumatic loss of epithelium. But the latter
would not present the peculiar ' string-of-beads ' appearance.
The floor of the loss of substance is formed by the superficial layers
of the cornea, and ansesthesia of the cornea is confined to this place,
and does not, as in herpes zoster, extend to the rest of the cornea.
The tension of the eye is generally reduced. Under favourable
circumstances this loss of epithelium may be rapidly repaired ;
although even then more slowly than one of equal dimensions, but
of traumatic origin. Usually the healing process is slow. >Some-
times more or less intense opacities form in the area and at the
margin of the ulcer, with hypopyon, iritis, etc., and the loss of
substance becomes deep, with a dentated margin. This unfavourable
course is the result of secondary infection of the ulcer.

Treatment at an early stage, before the vesicles have burst or
the loss of substance has become infiltrated, consists in protection
of the eye, and, when infiltration has set in, in disinfection, with
protection. In obstinate cases 4 per cent, saline subconjunctival

CHAP. V.

THE CORNEA. 133

injections are often of use. If the vesicles give great pain they may
be ruptured by dusting a little calomel into the eye, or by brushing
it with a camel' s-hair pencil wet with sterile saline solution after
which a well-fitting antiseptic dressing is applied. Cocaine should
be used as sparingly as possible, ow4ng to its ill-effect on the epithe-
lium when used in excess. Atropine and warm fomentations are
indicated, and a weak yellow oxide ointment is of use in some cases.
Where the nostrils are affected, weak sublimate or other antiseptic
and alkaline washes should be applied.

Dendriform (SeVSpov, a tree) Keratitis. — This is not a very un-
common affection. It takes the form of a superficial and chronic
ulceration, with but little infiltration of its margins or floor, and
presents the appearance of a fine groove, or grooves, on the cornea.
It spreads chiefly over the central region of the cornea by throwing
out branches on either side, while on the end of each branch there
is usually a minute grey infiltration, and its true nature may easily
be overlooked unless the cornea be examined by the combined focal
method. Pain and irritation are sometimes severe, and again but
slight or absent. Some slight permanent opacity may remain
when cure has been effected.

Fig. 58 represents three of the most common forms of the disease.
At a, in the drawing on the left, there is a nebula where healing has
set in, while in another part of the same cornea the process is in an

Fig. 58.

active stage. In the central drawing, near the upper corneal
margin, there is a fine herpetic-like eruption, and a long groove
passing down from it. And, in the drawing on the right, the
tendency to branch is well shown.

In cases which have been long neglected, and in which the

34 DISEASES OF THE EYE. [chap, v.

disease has run riot over the cornea, no healing process having set
in, the surface becomes dull grey and irregular, as though ploughed
up, the primary characteristic appearances being lost by reason of
the amount of disease present. The ulceration rarely becomes
septic. Some patients never have more than a single attack, while
in others several recurrences, sometimes at intervals of one or more
years, may take place, aud in such cases iritis is liable to occur.

The Cause has not been definitely ascertained. The opinion is
strongly held by some, that these ulcers result from a herpetic
eruption on the cornea, and they certainly occur under the same
conditions as herpes.

Treatment. — Curetting with a sharp spoon, with the subsequent
application of 1 in 1000 solution of corrosive sublimate to the
cornea, is recommended by some, also the application of pure car-
bolic acid to the ulcer with a finely pointed wooden match, care
being taken to confine it to the ulcer. The actual cautery is some-
times useful. But these remedies often fail to produce a cure.

Absolute alcohol has proved in our hands an almost certain,
as well as a rapid, cure. A bit of matchwood is sharpened to a fairly
fine point, and around the latter a little cotton wool is rolled not very
thickly. This is moistened with absolute alcohol, and the ulcer is
then rubbed with the point with such pressure as to take away the
epithelium, and, so far as possible, the rest of the corneal surface is
avoided. Immediately afterwards the conjunctival sac is freely
washed out with sterilised salt solution, to remove all surplus
alcohol, which would increase the subsequent pain. The application
is painful even with cocaine. As a rule there is pain for some hours
afterwards, and for this hot fomentations afford the best relief ;
cocaine is of little use. Usually one application is sufficient to pro-
duce cure, but some cases require it to be repeated after four or five
days. It is not desirable to repeat the application more than once or
at most twice, as the corneal epithelium is then liable to become de-
ranged, and filamentary and bullous keratitis may be produced. Pure
carbolic acid acts as well, and has the advantage over alcohol, in that
its action can be more easily limited and that it is much less painful.

The application of a fine point of sulphate of copper to the
ulceration also produces some good cures. It is less painful than
the alcohol, because its action is easily confined to the ulcerated
part, but it is not so certain in its action.

CHAP, v.] THE CORNEA. 135

Bullous Keratitis. — Bullae very rarely form on the cornea. They are
seldom the primary condition, but usually depend on a diseased process
in the true cornea. This process may itself be a primary disease ; but
more commonly it, too, is secondary to deep changes in the eye, such as
absolute glaucoma, iridocyclitis, etc. Very rarely bullae are seen on the
cornea of an otherwise sound eye, in a person whose health is in a debili-
tated state. Bullae on the cornea are sometimes caused by blows on the
eye, or by direct traumata of the cornea. The formation of a bulla is
attended by much pain and photophobia, which disappear as soon as the
bulla ruptures. One, or more than one, bulla may form at a time. After
a day or two the bulla rviptures, and its walls hang in shreds from the
surface of the cornea, and may produce the appearance of filamentary
keratitis, and the seat of the bulla presents shallow depressions. These
losses of substance heal without leaving any permanent opacity. After
an interval of days or weeks another crop of bullae appears, and runs the
same course.

Treatment. — The bulla? should be opened, and their walls snipj)ed
away with a scissors, and a bandage applied. The recurrent attacks
may cease after a length of time ; but, if it be a secondary affection, treat-
ment can influence it only by relieving the process in the cornea which
gives rise to it. If it be a primary process, w^arm fomentations, atropine,
and a bandage, with remedies directed to the correction of any fault in
the general state of the health which may exist, are suitable.

Filamentary Keratitis. — This is very rare. Its name is due to the
fine threads, like twisted spun-glass, several of which hang from the sur-
face of the cornea, and give the condition its characteristic appearance.
These threads never reach a length of more than 3 or 4 mm., and are
composed of twisted proliferating epithelial cells, each thread ending in
a bulbous enlargement caused by degeneration of the epithelium. The
condition may result from a superficial trauma of the cornea, or from a
bullous or herpetic keratitis, also after several applications of absolute
alcohol, when used for dendritic keratitis.

Treattnent. — The instillation of a 3 per cent, solution of chloride of
ammonium into the eye every two hours, by which the exfoliation of the
epithelial growth is promoted and hastened, produces a rapid cure. Pro-
tection of the eye with a dressing and bandage is important.

Keratitis Aspergillina. — This rare disease was described by Leber. The
appearance presented is that of an ulcer from 3 to 5 mm. in diameter,
occupying a rather central position in the cornea. The surface of the
ulcer is of a greyish or whitish yellow, and is very irregular. A striking
and characteristic appearance is the dryness of this surface, the copious
discharge of tears flowing over it without seeming to wet it. The rest
of the cornea is slightly opaque and dull, and there is a small hypopyon
present. The conjunctiva is injected and swollen, and is covered with
some mucovis secretion. The eyelids are rather swollen. There is photo-
phobia and often severe pain. Masses removed from the surface of the
ulcer and examined with the microscope are found to be full of the
aspergillus fumigatus. It may usually be ascertained that an injury has
preceded the appearance of the ulcer.

13G DISEASES OF THE EYE. [chap.

Treatment. — The membranous mass which forms the floor of the
ulcer should be peeled off, and the underlying surface cauterised and
dressed with xeroform, after which a good and rapid cure takes place.
Hot fomentations should not be used, as they promote the growth of the
fungus.

Tubercular Ulceration of the Cornea. See p. 143.

{h) Non-Ulceeative Inflammations of the Cornea.

Abscess. — This affection is on the borderland between the
ulcerative and non-ulcerative. inflammations of the cornea ; for in
one case it results in an ulcer — usually the ulcus serpens — while
again it runs its course "without ulceration. The abscesses which
are seated in the more superficial layers are those which go on to
ulceration ; those in the deeper layers are less likely to do so.

Abscess differs from infiltration in that the pus which forms it
destroys the true corneal tissue — the fibrillae and fixed corpuscles —
and does not merely lie between them.

Signs and Symptoms. — The appearance presented is that of a
yellowish circumscribed opacity, more intense at its margin than
at its centre, seated at or near the middle of the cornea,
and surrounded by a light grey zone. It is usually round in shape,
but when situated near the edge of the cornea it is apt to be
crescentic. The surface of the cornea just over the abscess is at
first a little elevated over the general surface, but later on becomes
flattened, owing to a falling-in of the normal layers anterior to
the abscess ; and the epithelium of the flattened part has a dull,
breathed-on look. The rest of the cornea may also lose its brilliancy,
although in a much less degree. Hypopyon and iritis are constant
attendants upon corneal abscess. There is much injection of the
conjunctival and ciliary blood-vessels. Severe pain in and about
the eye, and blepharospasm, are common ; yet occasionally a
corneal abscess is attended by but little pain or other irritation.

Progress. — The abscess spreads through the cornea, usually
advancing at the side where the opacity is most intense. Before
long, if the abscess be superficial, it may become converted into an
ulcer, and may result in an ulcus serpens, already described (p. 124).
The deeper abscesses spread through the cornea more or less widely,
and ultimately become absorbed, without having caused ulceration.

CHAP, v.] THE CORNEA. 137

But even these abscesses leave considerable opacity behind. The
process which ends in ulceration is the more common of the two.

Etiology. — Abscess is the result of infection of the cornea with
pyogenic organisms, which reach it either from without, through
some traumatic loss of substance of the corneal epithelium, or
from within, by the agency of the blood. The micro-organisms,
which are introduced through a superficial loss of substance, may
either have been on the foreign body which produced the injury,
or they may have been present in the conjunctival sac, or in the
lacrimal sac. Infection through the blood is occasionally seen in
some acute exanthematous diseases, such as scarlatina, measles,
and smallpox ; more especially in the latter in its convalescent
stage.

Treatment. — Atropine, warm fomentations, and a dressing. But
if these mild measures do not in a day or so arrest the progress of
the abscess, the same treatment must be adopted as for purulent
ulcers, and resort must be had either to the actual cautery or to
Ssemisch's operation (p. 127).

Ring Abscess. — This is a purulent circular infiltration of the cornea
lying a few inillimetres inside the actual margin, and it usually becomes
converted into a ring ulcer. The conjunctiva is chemotic, and from it
there is a greenish yellow discharge. It is not a common affection, and is
caused by metastasis and perforating wounds, including operation wounds,
at any part of the cornea, and sometimes follows on perforating wounds of
the sclerotic. It may also occur after spontaneous perforation of a corneal
ulcer, or from the infection of an old incarcerated iris prolapse. Its pro-
gress is extremely rapid, leading to complete necrosis of the cornea and
to panophthalmitis within a few days after the perforating injury is sus-
tained, and often rendering excision or evisceration necessary almost as
soon as the case comes under observation. In some cases, especially in
those of metastatic origin, the infiltration inay disappear without loss of
substance, while in others it may be possible to save some sight, or at
least the shape of the eyeball. The micro-organism concerned is the
bacillus pyocyaneus, which produces virulent toxine in large quantity.

Treatment. — Ssemisch's operation. Atropine, and careful cleansing
of the floor of the ulcer and conjunctival sac with perchloride of mercury
solution 1 in 2500. Subconjunctival injections of mercury oxycyanate
(1—5000).

Syphilitic Diseases of the Cornea. Disuse Interstitial or Paren-
chymatous Keratitis. — This is by far the most common, and best
known, of the syphilitic affections of the cornea. A very similar
disease is caused by tubercle (p. 143). The syphilitic form is most

138 DISEASES OF THE EYE. [chap. v.

frequently met with between the ages of five and fifteen. It usually
commences at one part of the margin as a light greyish opacity,
accompanied by slight injection of the ciliary vessels. The rest
of the corneal margin soon becomes similarly affected ; and the
opacity then gradually extends concentrically into the cornea.
In this way the whole cornea becomes affected by degrees ; and
its epithelium acquires a breathed-on or ground-glass appearance.
Occasionally the opacity commences at the centre, and not at the
margin of the cornea, often in the form of small grey spots, and
extends towards the margin, which it may not reach before clearing
commences.

The opacity lies in the deep layers of the true cornea, and is
slightly more intense here and there. It may be only a very light
cloud, or the cornea may be so opaque as to render the iris quite
invisible. Along with the opacity, vessels form in the deeper layers
of the cornea, but the degree of vascularisation varies much in
different cases. In some the presence of vessels can only be ascer-
tained by careful examination with a high convex glass (+ 16-0)
behind the ophthalmoscope, or with the corneal microscope ; while
in others the new vessels are present in great numbers, and can
be readily seen with the naked eye. In other cases close leashes
of vessels near the anterior surface of the cornea follow the opacity,
giving rise to the appearance known as the ' salmon patch.' The
infinite variety in the degree of opacity and in the amount and
arrangement of the vascularisation, results in great variation in
the appearances in different cases.

When the whole cornea has become opaque, it begins to clear
at the margin, and the central portion becomes even more opaque
than the margin had ever been. The clear margin gradually in-
creases in width, until only a rather intense central opacity is left.
This central opacity slowly breaks up, and becomes absorbed, but
not always completely ; and then considerable and permanent im-
pairment of vision may remain. Even in the more peripheral por-
tions of the cornea, in some cases, a faint maculated cloudiness may
be found on careful examination, years after the active process has
ceased.

In severe cases, iritis and chorioiditis are nearly always present,
although the latter is not observable until the cornea has become
clear enough to admit of an ophthalmoscopic examination. Strictly

CHAP, v.] THE COBNEA. 139

speaking, indeed, it should be regarded as a disease of the uveal
tract, to which the posterior layers of the cornea belong.

The two forms above described, one commencing at the margin,
the other at the centre of the cornea, and more or less vascularised,
but for the most part ultimately occupying the entire cornea, are
those we are wont to find in children and young adults. But in
older persons, up to thirty or thirty-five, milder forms of interstitial
keratitis are met with. These rarely occupy more than a small
region of the cornea, generally towards its centre, either as a patch
or as a ring of opacity, and with little or no vascularisation.

The affection is often accompanied by a good deal of pain and
blepharospasm, especially in the severe vascular forms, and there,
too, the tension of the eye is apt to be temporarily reduced ; but
again attacks of increased tension may occur, which in a few cases
may lead to Buphthalmos.

The acute stage of the disease lasts from six to eight weeks, or
longer. But the entire process may not be completed for many
months, or even a year. Relapses sometimes occur.

In children both eyes invariably become affected, although not
always at the same time, the onset in the second eye beginning
often when the inflammation in the first eye has made some
progress, or, perhaps, when the first eye has undergone cure.
It is important, in the very commencement of treatment, to ac-
quaint the patient or his parents with the likelihood of this course
of events.

In adults usually one eye alone is attacked, iritis is rare, the
duration of the process is comparatively short, and complete clearing
up is relatively frequent. The opacity is due to a round-celled in-
filtration of the deeper layers of the cornea, associated sometimes
with epithelioid and giant cells.

Causes. — The affection is more common in girls than in boys,
and most frequently appears during second dentition, when the
upper incisors are being cut, or at puberty.

It depends upon some serious derangement of the general
nutrition ; and this, in about 70 per cent, of the cases, is inherited
syphilis — a fact which was first pointed out by 8ir Jonathan Hutchin-
son. The children are often thin, anaemic, and of stunted growth,
with flat nose, cicatrices at the angles of the mouth, and are fre-
quently more or less deaf ; and the peculiarities of the incisor

140 DISEASES OF THE EYE. [chap. v.

teeth, so well known from Hutchinson's description, are present in
about one-half of the cases. The presence of the spirochsete pallida
in the cornea has been demonstrated microscopically.

Occurring in adults, the affection is rarely due to inherited
syphilis, although acquired lues may sometimes be taken as its
cause ; while, again, it will often be impossible to assign any origin
for it other than the universal one of exposure to cold, etc. Some
cases are due to tubercular disease (p. 143). While in some syphilis
and tubercle are combined and the cases react both to Wassermann's
and to the tuberculin tests.

Prognosis. — In children — in view of the possibility of an incom-
plete clearing of the cornea, as well as of the serious uveal com-
plications liable to supervene, and which may completely annihilate
vision — the prognosis must be guarded, although by no means
hopeless, in those cases where the opacity is very intense, or where
there is much vascularity. Yet, in the milder cases, a favourable
prognosis may be given. The affection recurs but very rarely.

In adults, as stated, the prognosis is much more favourable.

Treatment. — In the early stages no irritants should be applied
locally. Atropine is important for the prevention of iritis or of
posterior synechiae ; and the use of radiant heat, in the form of
hot poultices or fomentations, or the Japanese warmer, pr-omotes
the nutrition of the cornea and hastens the cure by absorption of
the cellular elements which form the opacity. Dionine is often very
useful. A dressing and bandage should be worn. Subconjunctival
injections of the oxycyanide of mercury 1 in 5000, are often useful.
When the acute stage is ended, dionine and the yellow oxide ointment
may be employed with benefit for stimulating the absorbents to
carry of! what remains of the opacity. Massage may be used with
advantage in both stages to disperse the infiltration. In severe
cases a course of mercurial inunctions, continued for several weeks,
is very advisable ; care being taken not to allow stomatitis to
exceed moderate bounds. Salvarsan does not seem to act more
rapidly in the cure of interstitial keratitis due to congenital syphilis
than does an active mercurial treatment, but a few very good results
have been obtained by it. In mild cases a tonic plan of treatment,
with iodide of iron and cod-liver oil, is the most suitable.

Counter-irritation, in the form of blisters to the temple or a
seton in the scalp, is extensively employed by some surgeons.

cHAt. V.I THE CORNEA. 141

We do not use this treatment, as we doubt its value, and are loth
to add to the worries inseparable from so wearisome a disease.

The following much rarer forms of syphilitic disease of the
cornea are described : —

Sfecific Punctiform Interstitial Keratitis. — Circumscribed, pin-
head-sized, .greyish infiltrations form at various levels in the
otherwise clear stroma of the true cornea. They do not grow
larger, nor suppurate. They form rapidly, and disappear rapidly
when cure commences, leaving little or no opacity behind. The
affection is not associated with iritis, but there is usually some
ciliary injection. In somewhat similar cases the punctiform opacities
are not so defined, but are surrounded by a halo of lighter opacity,
and iritis is present. This affection is a manifestation of tertiary
syphilis, and the punctiform opacities have been regarded as the
products of a gummatous inflammation. The treatment would be
iodide of potash internally, and locally atropine, warm fomentations,
and a bandage.

Gumma of the Cornea. — Some cases of true gumma of the cornea have
been recorded. The growth appears as a pale grey or whitish elevation,
more or less vascularised, on the cornea. The diagnosis depends very
much on the patient being the subject of tertiary syphilis. The treatment
is iodide of potash, salvarsan, or mercury.

Keratomalacia is also reckoned by some to be a syphilitic affection
(p. 13C).

Fig. 59. — Xodular Keratitis. Mr. W. J. Hancock's case. Trs. 0. S. xxv.

Guttata or Nodular Keratitis, and Grating-like or Reticular Keratitis (Fig.
59). — Nodular or reticular keratitis — a satisfactory title is wanting — is a
rare disease. Its presence is apt to be overlooked in the early stages ;
for by focal illumination the cornea may seem perfectly normal, and the
rest of the eye, excejDt perhaps for some slight distension of the anterior
ciliary and larger conjunctival vessels, is healthy, and the eye is free from
irritation. Ophthalmoscopic examination shows a number of small opaque
patches of all shapes, occupying the most central portion of the cornea,
while between them, and sometimes reaching out more towards the

142 DISEASES OF THE EYE. [cHAr. V.

periphery, innumerable very fine dots are present — nodular keratitis. In
some cases the opaque patches are absent, while a number of fine forked
lines are seen in the early stage outside the central region, which at first is
occupied by fine dots alone. At a later period, the arrangement of the
radiating forked lines assumes a somewhat reticulated appearance, like
that of a grating, and Ihey extend to the centre of the cornea — reticular
or grating-like keratitis. The corneal microscope shows that these dots,
patches, and lines are greyish, and situated close under the epithelium.
The surface of the latter is, in the early period, in no way altered.

Gradually the diseased appearances increase in amount, the anterior
ciliary vessels become more distended, vision sinks lower, and the patient
may sometimes complain of slight pain, with lacrimation, and swelling
of the eyelids ; but more commonly there is no irritation. The lines, dots,
and iDatches now begin to show slight elevations on the cornea, although
covered by epithelium. At a still later period the opacity in the centre of
the cornea becomes more intense, a marginal zone of the cornea remaining
fairly clear. At this stage the diagnosis may again become doubtful, owing
to the amount of the disease which obscures the characteristic appearance

Both eyes are always affected, either simultaneously, or with a short
interval. The disease is exceedingly intractable and chronic, lasting inany
years, and finally causing much loss of sight. Most of the cases observed
have been in young adult males, and it often attacks more than one member
of a family, in one or in succeeding generations — it is, in fact, one of the
family diseases. It begins between the tenth and thirteenth year. No
relation to syphilis or other constitutional disease has been made out.
It seems to be a degenerative affection.

Treatment. — Treatment, so far, has proved of little, if any, benefit.
Yellow oxide of mercury ointment, warm fomentations, galvanism, and
chloral hydrate eye-drops have been used. Dionine and subconjunctival
injections should also be given a trial.

Fig. 60. — Forms of Discoid Keratitis. (After Schirmer.)

Discoid, or Annular, Keratitis (Keratitis Disciformis of Fuchs) (Fig. 60).
— This disease occurs for the inost part in persons of middle age, and fre-
quently commences with slight defects of the epithelium caused by traumata
or by herpes. It has also been seen by Schirmer in coiuiection with vaccine
vesicles on the eyelids or conjunctiva. It is characterised by a delicate
grey disc, which is situated deeply in the true cornea, at or near its central
region, and which is marked off sharply all round from the normal peripheral
portion of the cornea by a more intensely narrow grey margin or ring ; or,
outside this ring, there may be another or even two more peripheral rings,
concentric with each other. Witli the corneal microscope grey striae can

CHAr. v.] THE CORNEA. 143

sometimes be seen in the opacity which may radiate out into the clear
cornea, parallel with each other or crossing at various angles, similar to
those which occur in some other keratitidos. The surface of the affected
region is dull and its sensation diminished. In the course of the malady,
wliich may run over several months, slight superficial ulcerations occur,
and finally a rather intense opacity is left at the seat of the disease. The
uveal tract is not usually imphcated, but in rare instances the presence of
some punctate deposits may be detected. Occasionally glaucoma sets in.
Treatment is of little avail. It should consist in atropine, bandage,
hot fomentations, sub-conjunctival saline injections, and dionine.

Tubercular Keratitis. — Tubercular disease of the cornea presents
itself in several forms : —

1. Pale yellow nodules which appear at the corneal margin,
extend to its deep, but not to its deepest, layers, and protrude,
slightly over its surface, accompanied by ciliary injection. These
nodules advance towards the centre of the cornea, become confluent,
and finally undergo absorption, leaving an intense opacity behind ;
or they may break down into ulceration, which may occupy the
greater part of the corneal surface. The ulcer never perforates,
and after a time healing takes place with cicatricial opacity, which
may clear up to a great extent. This is the only truly primary
form of tubercular disease of the cornea, no other part of the eye
being affected, and it is rare. In the other forms of tubercular cor-
neal disease the process is propagated to it from neighbouring parts.

2. Diffuse interstitial (or parenchymatous) keratitis. In about
70 per cent, of the cases of this affection, syphilis, congenital or
accjuired, is recognised as its cause (p. 137). It is held that of the
30 per cent, wdiich remain most, if not all, of the caries depend on
tubercle, but without the presence in the cornea of tubercular
nodules. Tubercular disease of the anterior uveal tract (chap, vii.)
co-exists ; and, presumably, the corneal affection is the effect of
toxines diffused in the cornea from the angle of the anterior chamber.
This form is capable of complete retrocession.

3. Greyish sclerotising opacities caused by tubercular nodules,
which grow into the corneal margin in its deepest layers from the
ligamentum pectinatum. These opacities occur at several parts
of the periphery of the cornea ; and, by throwing forward tongues,
they slowly spread into the cornea. Although the process may
cease at any point, the cornea remains very opaque at the parts
attacked, with resulting disfigurement or loss of sight.

144 DISEASES OF THE EYE. [chap. v.

4. Miliary tubercular nodules may form in the cornea in con-
nection with tubercular episcleritis at the corresponding portion
of the corneal margin, and may spread further into the cornea.
These nodules do not ulcerate, and ultimately they disappear, leav-
ing opacity behind.

Secondary pannus, ulcers, and granulations, may follow tubercle
of the conjunctiva. The ulcers sometimes perforate. In the scrap-
ings from tubercular ulcers the tubercle bacillus may be found.

Treatment. — For tubercular ulceration, curetting, with the
insufflation of xeroform, or, should these fail, the cautery. For
the other forms a course of tuberculin is indicated (chap. vii.).

Keratitis Punctata. — The term keratitis punctata was originally
used to denote the condition associated with irido-cyclitis and
sympathetic ophthalmia, which consists in the deposit of lymph
in the form of fine dots on the back of the cornea, derived from
inflamed portions of the uveal tract, mainly from the ciliary pro-
cesses. But for this condition the term 'punctate deposits' is to
be preferred to keratitis punctata. (Chap, vii.)

Fuchs has described a form of keratitis which he terms Keratitis
punctata super ficialis , and which has a good claim to that name. It
begins with the symptoms of an acute conjunctivitis, but there is decided
pericorneal injection, while the conjunctiva is not much injected, nor is the
discharge mucous or purulent, but is rather an abundant lacrimal secretion.
There is j)hotophobia and pain. Either at the same tiine, or some days
or weeks afterwards, minute grey spots may be seen in the most superficial
layers of the cornea, the epithelium over the spots being somewhat raised
up, giving a dull appearance to the corneal smface. The spots are often
arranged in groups or rows, and may be scattered over nearly the entire
cornea, or else confined to its central region. There may be but a few of
them, or there may be a hundred or more, and one or both eyes may be
affected. The initial irritative symptoms soon disappear ; but the spots
themselves remain for many weeks, or even months, and finally fade away
completely. The disease is more common in young people than in later
life, and occurs usually in connection with a catarrh of the air passages ;
but it must not, by reason of this, be confounded with herpes of the cornea.
The spots are often very faint, and hence can easily be overlooked, unless
searched for with the combined focal method. In this country the affec-
tion is rather rare, but several cases of it have come under our notice.

The Treatment should consist in atropine, dressing and bandage, yellow
oxide of mercury ointment, massage, and warm fomentations. To hasten
the cure, in some long-drawn-out cases, removal of the corneal epithelium,
which is to a great extent the seat of the disease, has been recommended.

Sclerotising Opacity of the cornea sometimes complicates

CHAP, v.l THE CORNEA. 14i

scleritis, or disease of the ciliary body (Syphilis, Tubercle). It
affects the margin of the cornea in the neighbourhood of the scleral
affection, but not extending more than 2 to 3 mm. into the cornea,
except in very severe cases. It is an intense white opacity situated
in the true cornea (Plate II. Fig. 5), and is apt to remain as a per-
manent opacity, even when the scleritis undergoes cure. In such
cases of sclero-keratitis iritis is often present.

Treatment. — If the inflammation has subsided the opacity can
no longer be cured. For the acute stage see treatment of
scleritis.

Ribandlike Keratitis (Transverse Calcareous Film of the Cornea ;
Calcareous Film of the Cornea). — This is a degenerative alteration
of the cornea w^hich occurs chiefly in eyes destroyed by severe intra-
ocular processes, such as irido-cyclitis, sympathetic ophthalmitis,
glaucoma, etc.

It also occasionally occurs as a primary disease in some persons
of advanced life. In these latter instances glaucoma often comes
on at a later period, or the corneal disease may be followed by
irido-cyclitis, or central chorioiditis. It seems probable that,
in these primary cases, the cause of the degeneration is simply a
loss of vital energy in the corneal tissue, due, it may be, to vascular
changes.

The disease occupies that transverse strip of the cornea which
is uncovered in the commissure of the eyelids during waking. It
usually commences on the inner margin of the cornea, but soon
appears at the outer margin, and advances from each direction
towards the centre, where the two sections join. It presents the
appearance of a greyish opacity, sometimes with a brownish tinge.
In most cases, white calcareous deposits are present in and under the
epithelium. In blind eyes which are constantly rolled upwards, the
opacity is found, not in the central transverse section of the cornea,
but in the exposed lower third. The opaque masses consist of car-
bonate and phosphate of lime. Leber puts forward the view that
an abnormally abundant supply of phosphate of lime in the blood,
and nutritive fluid of the cornea, is the cause of this condition, the
rapid evaporation on the exposed part of the cornea being the reason
why the deposit takes place there. The deposit is at first in Bow-
man's membrane, but later on it may appear in the anterior layer of
the true cornea, and in the epithelium.
10

146

DISEASES OF THE EYE.

[chap. v.

Treatment. — Some improvement may be effected by scraping
away the chalky deposit.

Superficial Epithelial Dystrophy of the Cornea. — This is a degenerative
affection of the cornea which occurs in old people, especially in women.
It is characterised by a superficial central cloudiness over which the
epithelium is dull and uneven. Small vesicles appear, and also clear spots
or pits, in the opaque area. The cornea becomes insensitive. The disease
sjDreads as years go on, and treatment is of no avail. A somewhat similar
appearance occurs after removal of the thyroid gland, in myxoedema, and
at times also in old cases of glaucoma.

ECTASIES OF THE CoRXEA.

Staphyloma of the Cornea, except in the very rare cases in
which it is congenital, is the result of a perforating ulcer of the cornea,
and the methods for obviating its occurrence have been set forth
at p. 121.

The ulcer, having healed, may present a w^eak cicatrix, which
becomes bulged forwards by even the normal intra-ocular tension.

If the iris be not incarcerated in
this cicatrix the anterior chamber
will be made deeper. But staphy-
loma cornese, in which the iris is
incarcerated, is the more common
condition. When a corneal ulcer
is large, a correspondingly large
portion of iris is liable to become
prolapsed into it, and to form a
bulging mass. This may burst and
collapse, and a flat cicatrix may be
formed ; or, if it do not rupture,
it may form what is termed a
partial staphyloma of the cornea
and iris, the latter becoming con-
solidated by the formation of a layer of connective tissue over
it (Fig. 61).

If the whole, or a very large part, of the cornea be destroyed
by an ulcer, the iris is completely exposed. It soon begins to be
covered with a layer of lymph, which gradually becomes converted
into an opaque cicatricial membrane. Should this not be strong,
the normal intra-ocular tension is sufficient after a time to make it

Fig. 61. — Almost total staphy-
loma of cornea, with great thick-
ening of its cicatricial tissue.

CHAP, v.] THE CORNEA. 147

bulge ; or, increased iiitra-ocular tension may arise in consequence of
further changes within the eye, and then bulging of the pseudo-
cornea all the more surely comes on, and the condition is termed
total staphyloma of the cornea, although obviously the term is
somewhat strained, as in fact there is no cornea. Such a staphy-
lomatous cornea is intensely white, and would correctly be called
a leucomatous staphyloma. Sometimes a total staphyloma has a
lobulated appearance, owing to the pseudo-cornea having some of
its fibres stronger than others ; and hence the name given to the
condition (from o-ra^vXt], a hunch of grapes), and which has in time
become applicable to almost any bulging of the cornea or sclerotic.
Such staphylomata are apt to increase gradually to a very large size.

Treatment. — In cases of partial staphyloma, where a clear portion
of the cornea remains, an iridectomy is frequently indicated for
the reduction of the tension — so that further bulging may be arrested
— as well as for the sake of the artificial pupil, which may improve
sight, in cases where the normal pupil is obliterated by corneal
opacity. If the tension becomes raised again after iridectomy, a
trephine operation may be done (see chap. ix.).

When, sight having been lost, the staphyloma is very pro-
minent, or when total staphyloma is present, enucleation of
the eye-ball, or one of the following operative measures, must be
adoped.

Abscission. — A cataract knife being passed through the base
of the staphyloma, with its edge directed upwards, the upper two-
thirds of the staphyloma are separated off, while the remaining
third is detached by means of scissors. If the lens be present it
must now be removed. The wide opening becomes filled up with
granulations, and becomes cicatrised, or the opening is closed with
conjunctival sutures.

The foregoing and other methods of abscission are only applicable
where the tension is either low or normal. If it be high, the liability
to intra-ocular haemorrhage during the operation makes enucleation,
evisceration, or Mules' operation more suitable proceedings. Indeed,
probably most surgeons would now employ one of the two latter
operations in all these cases.

Evisceration was proposed to obviate meningitis after the removal
of suppurating globes, and also to take the place of enucleation in
cases of sympathetic ophthalmitis. Practically all surgeons are

[48 DISEASES OF THE EYE. [chap. v.

now opposed to its employment in the latter cases, but for staphy-
loma of the cornea it is not open to objection.

The cornea is removed by making an incision with a Gra3fe's
knife, so as to include one half of the corneo-scleral margin, and by
completing the circumcision with scissors. All the contents of the
globe are then evacuated by means of Mules' scoop, care being taken
to remove the chorioid unbroken by carefully peeling it from the
sclerotic margin backwards, until it is only held at the lamina cribrosa.
The scoop is then used to lift out the separated unbroken chorioid
and the other contents of the globe.

Finally, the margins of the sclero-conjunctival wound are drawn
together with a few points of suture. The whole proceeding should
be done with strict aseptic precautions, chief among which is the
free use of irrigation with a 1 in 5000 solution of corrosive sublimate
before, during, and after the operation, the interior of the globe
being most carefully washed out w^ith the solution in a full stream.
The result is a fairly good and freely movable stump for the applica-*
tion of an artificial eve.

Mules' Operation. — This proceeding — a modification of the foregoing —
was also proposed by Mules for cases of threatened sympathetic ophthal-
mitis, and, like simple evisceration, has not met with universal accejatance
in those cases, because it is held not to afford sufficient protection against
sympathetic ophthalmitis. In cases of staphyloma, however, and in some
other conditions where the questions of sympathetic ophthalmitis, or of
a new growth in the eye to be operated on, do not enter into consideration,
no proceeding is more satisfactory, at least in young persons, than this
beautifvil one of Mules'. Its object is to provide a still better stump for
the artificial eye by the insertion into the scleral cavity of a hollow glass
sphere, and the prothesis it provides is almost perfect. It is performed as
follows : —

The cornea is removed — the conjunctiva having first been freed from
the scleral edge towards the equator of the eyeball — and the contents of
the eyeball evacuated, as in simple evisceration. The opening is now
enlarged vertically, to admit of the introduction of one of the glass spheres.
This introduction is best effected by means of a special instrument designed
for the purpose by Mules. The spheres are made in several sizes to suit
different cases, and it is not desirable to use the largest which will fit into
any given eye. The sphere having been inserted, the margins of the sclerotic
opening are united vertically by some points of interrupted suture, for
which purpose silk or hemp is preferable to catgut, as the latter is apt to
undergo absorption before complete union has taken place. The conjunc-
tival opening is then closed by another set of sutiues placed at right angles
to the sclerotic line of closure. Similar aseptic precautions ai'e requu'ed,

CHAP, v.]

THE CORNEA.

as in simple evisceration, and all bleeding should have ceased in the cavity
before the glass sphere is inserted. Before the lids are closed the anterior
surface of the globe is well covered with boric acid or xeroform. A firm
bandage is applied. The eye is not dressed for forty-eight hours, and
subsequently once every twenty-four hours, using the sublimate solu-
tion freely. There is generally some reaction, consisting of chemosis,
swelling of the eyelids, and pain, and sometimes these symptoms are
very marked, especially if too large a sphere have been employed. In the
course of a week or so this all passes off, and a very perfect stump is
obtained.

We have only once seen a glass sphere broken by a blow after a Mules'
operation. Various substances have been utilised to replace the glass
ball, gold, silver, bone, etc., and they have also been introduced into the
Capsule of Tenon after enucleation.

With a well-fitting glass eye, the cosmetic result of the Mules' operation
is infmitely better than that produced either by excision or by evisceration
of the eyeball. It is more uniformly successful in young people than at
more advanced ages, and therefore it is better not to use it in persons over
twenty-five. To ensure success it is an important point that the glass
globe be not too large — it should be an easy fit for the cavity of the sclerotic.
In case the sutures give way, and the sclerotic opening gapes, an attempt
may be made to reclose it with new sutures, but this is not often successful.
As a rule the glass globe must in that event be removed, and the case then
becomes one of simple evisceration.

Komoto's operation is a very good and simple one, for large and especially
thin staphylomata. The cornea is transfixed horizontally, with the edge
of the knife forwards and the wounds at the points of transfixion enlarged.
The knife is then withdrawn, the staphyloma is seized on each side with
forceps by an assistant, and the section completed with scissors (Fig. 62 A,).
A suture (c) is then introduced at the apex of the triangular incision the

^^^~~~~.^Jy>^.

^^J

Fig. 62.

Fig.

63.

Fig. 64.

two lateral portions of the staphyloma are trimmed, and two other sutures
applied at a and h (Fig. 63 B).

Another useful method (Attias') is shown in Fig. 64. The staphyloma
is transfixed and divided horizontally (D to E). Sutures are now passed,

[50 DISEASES OF THE EYE. [chap. v.

before any further incision is made, from a to a and 6 to 6 ; with a fine
scissors, one blade being introduced into the first incision, triangular flaps
are cut out, avoiding of course the sutures. The effect may be diminished
by removing only three triangular flaps.

We have been doing this operation for some years, but without sutures,
and it is astonishing how the flaps come together after a time, even though
they may not lie in apposition when made.

In most cases it is as well to remove the lens, and if necessary some of
the iris. When introducing sutures into the cornea it is better when
possible not to pass them through the whole thickness, but only through
the anterior layers.

Conical Cornea, or Keratoconus, is a cone-shaped protrusion of
the cornea occurring in an otherwise healthy eye (Fig. 65), The
cornea remains clear, except sometimes just
at the apex of the cone, where a slight
nebula may be present. The position of
the apex is usually not quite central, and is
then most commonly either in the lower
outer, or lower inner quadrant of the pupil.
If the apex be touched with a probe its
extreme thinness may be ascertained. The condition is easy of
diagnosis in its advanced stages by mere inspection of the cornea,
especially in profile. When seen from the front it gives the e5^es
of the patient a peculiar glistening appearance.

In the early stages, when the light is thrown on the cornea from
the ophthalmoscope mirror, the corneal reflex will be noticed to be
smaller at the centre, owing to the greater curvature there, and
a dark shadow, circular or crescentic in shape according to the
incidence of the light, appears between the margin and the centre
of the cornea. The ophthalmoscopic image of the fundus and the
corneal images as seen with the astigmometer appear distorted.

In some extreme cases the patient observes a pulsating altera-
tion in the size of the objects looked at. This is due to the pulsation
of the apex of the cone, imparted to it by the intra-ocular circulation,
and is comparable to the pulsation of an unclosed fontanelle of the
skull. Objectively the pulsation can be seen M^th the corneal
microscope and with Schiotz's tonometer (see chap. ix.). Sensation
at the apex of the cone is often diminished. A brownish ring (due
to the deposit of haemosiderin) has been observed in the cornea in
some cases.

CHAP, v.] THE CORNEA. 151

On examination with the keratoscope the corneal reflex, instead
of being normal, as at A (Fig. 66), is altered as at B or C.

With the astigmometer, the portions of the images on the apex
are smaller and overlap, while the more peripheral portions may
only touch, or may even not come into contact.

The process begins in early adult life, progresses slowly, never
leads to rupture or ulceration of the cornea, and, finally, after many
years, ceases to progress, but does not undergo cure. Both eyes are
apt to become attacked, one after the other. The disturbance of
vision is very great, owing to the extreme irregular astigmatism
produced.

Etiology. — There is very little doubt that this disease is due to

^p ^»

ABC

Fig. 66. — A, reflected image of Keratoscope on normal cornea. B, reflected
image at apex of cone in conical cornea. C, Reflected image slightly
eccentric in conical cornea.

some form of malnutrition. The individuals affected are generally
delicate, and almost always both eyes are affected. In some cases
the thyroid has been found enlarged and, associated with it, a
trophic disturbance of the skin and nails. Increased lympho-
cytosis has also been noted by some, but others deny that it is a
frequent occurrence in cases of conical cornea and believe that it has
no direct connection with this disease.

Treatment. — Optical. — {a) Correction of the refraction in the early
stages or in slight cases. A moderate improvement in vision may
be obtained by high concave or even convex cylinders, alone or com-
bined with concave sphericals. (b) Temporary removal of the
irregular refraction by the use of ' contact ' glasses. But these
are not very practical.

Reduction of tension. — Treatment by pilocarpine or eserine and
bandaging do not produce much effect, neither do iridectomy or
trephining alone effect a cure in most cases.

Excision of a portion of corneal tissue by means of a trephine
(Bowman) or with a Grsefe knife (Morton) has sometimes given good

152 DISEASES OF THE EYE. [chap. v.

results, but they have the disadvantage of leaving the cornea as
weak as before.

Cautery. — This is the method which is almost universally relied
upon at present. The object of it is to remove the conical distension
by the contraction which follows the burn, and at the same time
to strengthen the cornea by the formation of a firm cicatrix.

The electro- or thermo-cautery is applied to the apex of the cone,
or to one side of it, and a small circular area burnt deeply ; some
surgeons perforate the cornea, others do not, being afraid of the
possible dangers attendant on the presence of a fistula of the cornea
which may remain open for several weeks. Glaucoma has occurred
in some cases. We have frequently perforated the cornea and
have never had any bad result, and the effect is certainly greater
than in the cases in which the anterior chamber has not been opened.

Sir Anderson Crichett lays much stress on the graduated appli-
cation of the cautery. He first applies the cautery at a black heat
to the whole area intended to be cicatrised ; within this area a little
more is destroyed at a slightly increased heat, while the very apex
is touched with a cautery at a dull red heat. One sitting is sufficient.

Cauterisation without perforation may also be combined with
paracentesis of the cornea, and the anterior chamber can be evacu-
ated daily for a week ; or the effect of the cautery may be increased
by trephining at the sclero-corneal margin (chap. ix.).

With the object of increasing the solidity of the scar it has been
recommended to cauterise not only the apex of the cone, but also to
extend the area of cauterisation over a triangular portion of the
cornea with its base at the limbus in order to encourage the growth
of vessels into the scar, or a conjunctival flap can be drawn over the
burnt surface.

After the cicatrisation following on cauterisation is completed,
the scar may be tattooed, and an optical iridectomy will usually be
required, especially if the cone has been quite central. The cases
in which the apex of the cone has an eccentric position are those most
benefited by cauterisation, because the resulting scar interferes less
with vision than where it is central.

Atrophic Degeneration of the Margin of the Cornea (Marginal Groove
of the Cornea, Marginal Ectasy of the Cornea). — This rare disease occurs
mostly in persons of advanced life, and is always associated with an arcus
senilis. It is at first a shallow groove situated either immediately outside

CHAP, v.] THE CORNEA. 153

the arcus — that is, between it and the margin of the cornea — or on the
arcus, or immediately inside the latter. The inner margin of the groove
is steep, while its outer, or peripheral margin passes gradually to the level
of the cornea. In its early stages the floor of the groove is slightly, and its
inner margin more markedly, nebulous, but at a later period it becomes
quite pellucid. So that, if it occupy the arcus, the latter may disappear ;
and at no time is there any disturbance of the epithelium covering the
groove. Fine vessels often extend into the groove from the conjunctiva.
The groove usually commences in the upper margin of the cornea, and
sometimes extends around the whole margin. In the course of time — it
may be some years — the thin floor of the groove is pressed forwards by
the normal intra-ocular tension, and a pellucid bulging, or ectasy, takes
the place of the groove. Disturbance of vision is not complained of until
ectasy comes on, and it is caused by the resulting astigmatism, which is
inverse, or against the rule, and is sometimes very high. Slight irritation
of the eye — epiphora and photophobia — is present in some cases. The
disease is held to be a localised atrophy of the cornea, due to fatty
degeneration.

Treatment is not indicated until vision is deranged in the stage of
ectasy. Cylindrical glasses may then prove of great use. In many
advanced cases the galvano-cautery may be applied to the protruding
part, or it may be abscised and covered with a conjunctival flajD.

Tumours of the Cornea.

Primary tumours of the cornea are extremely rare. Epithelioma
and sarcoma have their origin not in the cornea, but in the limbus of the
conjunctiva (p. 100). Dermoid tumours are usually seated partly on the
conjunctiva and partly on the cornea. Yet a very few cases of papilloma,
epithelioma, and fibroma are recorded as taking their origin in the
cornea. Corneal cysts also occur.

Dermoid Tumours. — These are of a pale yellow or white colour, and
in size are from that of a split pea to that of a cherry. They are smooth
on the surface, dry looking, and sometimes have fine hairs, and sit usually
at the outer and lower margin of the cornea. In structure they resemble
that of the skin.

They often increase in size at puberty, and the hairs then grow. They
are congenital tumours, supposed to be due to an arrest in development,
and are sometimes accompanied by coloboma of the upper lid. They often
have a tendency to extend over the cornea. If this tendency be present,
the tumour must be removed by dissecting it off the cornea, care being
taken not to go into the deep layers of the latter.

Injuries of the Cornea.

Foreign Bodies in the Cornea, such as particles of iron, stone,
coal, etc., are amongst the most common of all accidents to the body.
The pain caused by these foreign bodies is very considerable. The
dangers which may follow on their presence in the cornea depend

154

DISEASES OF THE EYE.

[chap. v.

partly upon whether or not they carry infection, and partly upon
the depth at which they lie buried in the cornea. The deeper a
foreign body lies, the more difficult will be its removal, and the
greater must be the laceration of the cornea caused by that proceed-
ing. A foreign body which carries infection will be more likely to
set up serious inflammatory reaction than one which is aseptic, or
nearly so. For this reason it is important to ascertain, if possible,
the origin of the foreign body, although an apparently aseptic origin
must not set at rest all fear on this point. Chips of hot metal or
glass are, from their temperature, aseptic.

Many foreign bodies are so small as to defy detection, until
the cornea is searched with the oblique illumination — an aid which
should always be made use of, when the symptoms or history in
the remotest degree suggest the presence of a foreign body.

A foreign body which lies quite superficially in the epithelium
is easily removed by gentle wiping with a clean camel' s-hair pencil,
or soft cloth. Those which lie deeper require instrumental inter-
ference, in the following manner : —

The eye having been thoroughly cocainised, the patient is
seated, and leans his head €|ainst the chest of the surgeon, who

stands behind him (Fig. 67). With
the index-finger of the left -hand
the surgeon then lifts the upper
lid of the injured eye, pressing
the margin of the lid upwards and
backwards, while with the second
finger he depresses the lower lid in
a similar manner. By this means
the eyelids are held open, and also,
to a great extent, the motions of
the eyeball are controlled. The
foreign body is now pricked out of
the cornea with a special needle,
with as little injury of the general
surface as possible, the patient all the while directing his gaze steadily
at some given point. If the foreign body be deep in the layers of
the cornea, it must be dug out, as it were ; and a minute gouge is
made for this purpose. In cases where a chip of iron or steel has
lain for some time in the cornea, after its removal a small ring of

Fig. G7.

CHAP, v.] THE CORNEA. 155

rust will be seen surrounding the spot previously occupied by the
foreign body. This rust-ring is in the true cornea, and must be
carefully scraped away, or the recovery, by necrosis of the
affected part, will be much slower, and the resulting opacity much
greater.

Care must be taken not to infect the cornea in the removal
of a foreign body, and consequently thorough aseptic precautions
must be taken, especially as regards the instrument used. A
dressing is worn until the epithelium is regenerated — i.e. for a
day or two.

The magnet is of no use for the removal even of superficially
seated foreign bodies of steel or iron in the cornea.

Sometimes a foreign body in the cornea will be long enough
to protrude somewhat into the anterior chamber, and there is
danger that, in the attempts at removal, it may be pushed into it.
In such cases it is necessary to pass a keratome through the cornea,
and behind the foreign body, so as to provide a firm base against
which to work, or the keratome may be made to push the foreign
body forwards.

The wing-cases of small beetles and scales of seeds may get
into the eye, and adhere to the cornea, usually at the limbus, by
their concave surface, where they may remain for several days, or
even for weeks.

Simple Traumatic Losses of Substance, or Abrasions, of the
surface of the cornea, involving the most anterior layers of the
true cornea, or perhaps merely the epithelium, are very common
from rubs or scratches with branches of trees, finger-nails, etc.,
etc. Fluorescine is especially useful for diagnosis in these cases.
There is much pain, photophobia, and lacrimation ; the most
superficial lesions being the most painful owing to laceration of
the nerve-endings in the epithelium. These injuries heal readily
if the eye be protected with a dressing ; but when neglected, or if
septic matter have been introduced when the injury occurred, or
if it be present in the conjunctiva or lacrimal sac, these losses of
substance are capable of forming the startmg-point ot corneal
abscess, ulcus serpens, etc. The condition of the lacrimal apparatus
and of the conjunctiva should be noted, so that, if necessary,
suitable measures may be taken to obviate infection from those
regions. In addition to the dressing and bandage, atropine and

156 DISEASES OF THE EYE. [chap. v.

dionine should be used, along with a weak sublimate ointment
inserted into the conjunctival sac; but no cocaine, which desiccates
the epithelium and interferes with repair. The bandage should be
continued for some days after the loss of substance has been
repaired.

A remarkable condition known as Recurrent Abrasion, or Disjunction
of the Cornea (and also as Traumatic Keratalgia, and Recurrent Traumatic
Keratalgia), is sometimes observed to follow upon abrasions of the cornea.
Healing of the primary lesion having taken place in an apparently normal
manner, the patient, after an interval of days, weeks, or even months, on
awaking in the morning, is seized with severe pain, similar to that experi-
enced on the occasion of the injury. On examination of the eye a loss of
the epithelium, which may be greater or less in extent than was the primary
loss, is found at the seat of the original lesion, or, what is remarkable, it
may have taken place elsewhere on the cornea. Or, more rarely, instead
of a loss of epithelium, the latter may be raised up like a vesicle, or bulla.
Examination of such cases has shown that the epithelial covering of a great
part of, or of the whole of, the cornea may be easily lifted off with a forceps ;
in short, that the cohesion between epithelium and Bowman's membrane far
beyond the immediate seat of the original lesion has become imperfect.
Care of the eye by means of a dressing enables the renewed loss of substance
to be rapidly repaired ; but, after a period of quiescence, another attack
takes place on awaking in the morning, or in the course of the night, and
such attacks may continue to recur, even for several years. It is charac-
teristic of the affection that the attacks always take place on awaking —
a circumstance which is explained by the slight adhesion between palpebral
conjunctiva and corneal epithelium formed during sleep, so that on the
lifting of the eyelid the loosened epithelium is torn away, or lifted in a
bulla-like shape. There is some loss of sensation of the surface of the
cornea. After one of these attacks, examination of the corneal surface by
the usual methods may fail to reveal the presence of a loss of substance,
and then it may be discovered by means of transmitted light from a plane
mirror, which will display the defect as a black mark. The corneal micro-
scope, too, is useful here.

The cause of disjunction of the cornea has not been definitely ascer-
tained. The view has been put forward, and there is good evidence in
support of it, that the affection is due to a very slight degree of oedema
of the cornea of neurogenic origin, a derangement of the peripheral endings
of the fifth nerve in the cornea having been produced by the original injury.

Treatment. — Cocaine, owing to the disorganising effect it has on the
corneal epithelium, is not to be used at all, or as sparingly as possible. A
carefully applied dressing is important, and should be worn for long —
it may be weeks — after the recurrent lesion seems to be quite well. An
operative measure — namely, the removal with the forceps of the entire
corneal ei^ithelium or as much of it as easily comes away — is very effectual.
The denuded region is soon again covered over with epithelium, and this
new growth adheres in a healthy manner to its bed. Some surgeons

CHAP, v.] THE CORNEA. 157

remove the loosened epithelium with a camel's-hair pencil moistened with
chlorine water, and others take it away with a curette. The insertion into
the conjunctival sac of a non-irritating ointment every night at bed-time
is a most useful adjunct in the treatment by dressing or operation.

Blows on the eye, amongst other lesions, are liable to cause corneal
bullae, the walls of which consist of Bowman's membrane and the epithe-
lium. In some cases these bullae contain blood, derived no doubt from
the ruptured canal of Schlemm. Such bullae may also form after burns
with lime, etc.

Hsemorrhagic Discoloration of the Cornea is another condition caused by
blows on the eye. It produces a greenish or a reddish-brown colour in
the cornea. Haemorrhage in the anterior chamber is always present at
first. At first, too, the discoloration occupies the whole cornea, and after
a time begins to clear up from the margin towards the centre. The
l")rognosis for vision is good, if the eye be otherwise sound, but the
absorption of the colouring matter in the cornea is excessively slow, and
as much as two or three years or more may elapse before the process is
complete. Treacher Collins has ascertained that the peculiar discolora-
tion in these cases is due to the presence of haematoidin, which he
believes enters the cornea from the haemorrhage in the anterior chamber
tlirough Descemet's membrane by a process of diffusion. He did not
find any red blood-corpuscles in the cornea.

Injuries of the Cornea with Caustic Substances.— The caustic
substances whicli need enter into consideration liere are those that
most commonly come in contact with the cornea and conjunctiva,
either accidentally or maliciously. They are lime, ammonia, and
caustic potash ; also nitric acid, sulphuric acid, and acetic acid.
The subjects of these accidents sufier great pain, and on presenting
themselves soon afterwards the eyelids, even if not injured, are
found to be swollen and discoloured, and it is difficult to open
them in order to examine the state of the eye. There is chemosis,
and great irritation.

Burns of the cornea from lime or mortar, or whitewash con-
taining lime, are not uncommon amongst those engaged about lime-
kilns, or in the building trade. The lime destroys the cornea more
or less deeply, with resulting more or less intense permanent cicatricial
opacity. The lime, moreover, enters into chemical combination
with the corneal mucin or albumen, which causes further opacity.

As soon as possible after lime has entered the eye, it should
be removed as thoroughly as possible by means of forceps and free
washing out "with water ; or, better still, with saturated solution
of sugar, ^Yhich forms, with whatever loose lime may be present,
a substance that can be more readilv removed.

158 DISEASES OF THE EYE. [chap. v.

The removal of such albuminate of lime as remains fastened
deeply in the cornea is difficult to effect ; but when the immediate
irritation has somewhat subsided, the eye having been cocainised,
a 10 per cent, solution of neutral ammonium tartrate may be used.

The treatment of injuries with ammonia, caustic potash, and
other metallic caustics, is the same as that of injuries with lime.

Burns of the cornea with nitric, sulphuric, acetic, and other
caustic acids are treated with a J per cent, solution of caustic potash
as a bath, or poured into the eye as above described, the eye having
been cocainised.

It is hardly necessary to state that, in burns with such chemical
substances, the destruction of the corneal tissues is too often so
rapid and extensive, that no measure avails to avert a degree of
opacity of the cornea that must be seriously detrimental to vision,
particularly in view of the interval which in most instances elapses
between the accident and the treatment of the injury. And not
only is the cornea rendered opaque, but the inevitable injuries
caused at the same time to the conjunctiva by the caustic, give
rise to more or less symblepharon (chap, xviii.). In the severest
cases, suppuration of the cornea supervenes, and the eye is lost
through panophthalmitis.

Perforating Injuries of the Cornea.— In these cases the injury
done is rarely to the cornea alone, and at the first inspection the
attention of the surgeon is occupied less with the state of the cornea
than with the question as to whether, and to what extent, deeper
parts of the eye (iris, lens, vitreous humour, etc.) are involved.
Another very important point, which has often to be decided, is
whether or not the foreign body, which has perforated the cornea,
is contained in the eye. But these matters belong to future chapters.

A perforating wound of the cornea, which does not involve
any other part, is serious in proportion to its extent, and to the
probability of its being infected. Every perforating corneal wound
is followed by loss of the aqueous humour, which flows away through
the opening, and by consequent collapse of the anterior chamber ;
but this in itself is not a serious event. Short wounds close almost
at once (and through them indeed very little of the aqueous humour
may flow ofT), the aqueous humour is rapidly restored, and no harm
is done to the eye beyond a slight opacity, which, if in the pupillary
area, may cause some defect of vision ; or, should the wound be

THE CORNEA. 159

situated more peripherally, and should the iris have lain against the
cornea for a while, an anterior synechia may form.

Long wounds, which may even occupy the cornea in its entire
diameter without directly involving any other organ of the eye, are
almost certain to he complicated by prolapse of the iris between the
lips of the wound ; and, w^hen healing takes place, the prolapsed
portion becomes permanently incarcerated in the cicatrix. At the
least, ^this incarceration causes irregularity in the curvature of the
cornea, and consequent irregular astigmatism. But it may be
the starting-point of a staphyloma of the cornea, it may become
the cause of glaucomatous intra-ocular tension, or, if at any time a
slight trauma with loss of substance of its surface should occur, it
may take on septic inflammation, wdiich may spread rapidly to the
deeper uveal structures, leading to panophthalmitis and loss of
the eye.

Treatment. — In small uncomplicated perforating wounds, without
prolapse of iris, where the aqueous humour has not yet formed,
atropine should be freely used if the wound be towards the centre of
the cornea, or eserine if it lie towards the periphery, with the object
of preventing adhesions of the iris to the posterior aspect of the
wound, and a dressing and bandage should be applied to the eye.

In very recent injuries of this kind, in which there is a prolapse of
the iris, the prolapsed portion, if not very large, may sometimes be
reposed with a spatula or fine probe, aided by the action of atropine
or eserine, according to the position of the wound. But in many
instances this attempt will prove futile, while in those in which
there is suspicion of septic infection, it is unwise to make it. In
either circumstance the prolapsed portion of iris should be snipped
of! at its base. It is not enough to abscise a portion of the summit
of the prolapse. The prolapsed iris must be seized with an iris-
forceps, drawn forward so as to loosen, so far as possible, any ad-
hesions between it and the lips of the wound (or the adhesions may
previously be separated by a probe passed round the edges of the
wound), and cut off close to the cornea. This affords the best hope
that the iris may recede into the anterior chamber, without any of
it becoming incarcerated in the corneal wound while healing. In
badly lacerated wounds it is sometimes desirable to transplant
conjunctiva over them in order to promote the healing process
and to consolidate the cicatrix.

160 DISEASES OF THE EYE. [chap. v.

In cases which are not recent, the adhesions between cornea and
prolapsed iris will have become so firm, that it will not be possible
to separate them by any means, and the prolapse must be allowed
to become cicatrised over, the tension of the eye being kept low by
means of eserine, and transplantation of conjunctiva being per-
formed, to the end that a firm and flat cicatrix may be obtained.

Opacities of the Cornea.

Nebula, Macula, Leucoma. — These terms are applied to opacities
of varying degrees in the cornea, resulting from disease or injury.
They are really scars of the cornea, due to the formation of irregular
fibrous tissue, and as such are not accompanied, as keratitis is,
by ciliary congestion or photophobia. Lesions which involve the
epithelium of the cornea alone, undergo repair without any resulting
opacity. The term nebula is used for very slight opacities, often
discernible by oblique illumination alone. Macula indicates a more
intense opacity, recognisable by daylight. Leucoma is a completely
non-translucent and intensely white opacity, the result almost always
of an ulcer, which has destroyed most of the true corneal tissue at
the affected place ; indeed, it is often the result of an ulcer which has
eaten its way quite through the cornea. In these latter cases the
iris may have become adherent in the corneal cicatrix, and then the
term Adherent Leucoma is employed.

Eyes with an old-standing nebulous condition of the cornea are
often irregularly astigmatic or myopic, and cylindrical or concave
glasses sometimes aid the vision. It is probable that this myopia
is caused by the habitual close approximation of objects to the eye,
owing to the diminished acuteness of vision from the opacity of the
cornea. In children opacities of the cornea may be the cause of
strabismus and nystagmus.

Treatment. — Little or nothing can be done to reduce these
opacities. In slight and fresh cases, massage with the yellow oxide
of mercury ointment, or instillations of 5 per cent, dionine may
render them less intense.

In the case of a dense central opacity with clear cornea at the
margin, an iridectomy will in some instances improve the sight.

The Operation of Tattooing is a valuable proceeding for the im-
provement of the appearance of the eye in cases of leucoma. It is

CHAP, v.] TH^ CORNEA. 101

also useful for improvement of the sight, where the nebula occupies
only part of the pupillary area of the cornea. In these cases, much
disturbance of vision is caused by the dispersion of the light which
make its way through the nebula ; and when, by tattooing the scar,
all light is prevented from getting through it, more distinct vision
is enjoyed w^th that part of the cornea, opposite the pupil, which
is absolutely clear.

The material used is fine Indian ink rubbed into a very thin paste.
The eye having been cocainised, the leucoma is spread over with this
paste, and then covered with innumerable punctures by means of
de Wecker's multiple tattooing-needle, or with an ordinary discission
needle. The coloration remains sufficiently intense for some months,
but then often begins to get pale, owing to removal of the pigment.
The pigmentation lasts longer, if a single grooved needle be used.
The pigment is placed in the groove of the instrument, which is then
passed into the leucoma, in a plane parallel to its surface. On with-
drawal of the needle the pigment remains behind. A large number
of such channels must be made in close proximity to each other, until
the desired intensity of colour is obtained. Some operators remove
the corneal epithelium over the part to be tattooed, in order to
facilitate the entrance of the colouring matter into the true cornea.

In tattooing the cornea, the eye must not be fixed with a toothed
forceps, or else the conjunctiva may be tattooed. A forceps armed
with rubber is used, or the eye can be fixed by the surgeon with his
fingers, which at the same time take the place of a speculum (Fig. 67).

Keratoplasty or Transplantation of a Portion of Clear Cornea from a
freshly enucleated human eye has been performied in many cases of leu-
coma where sight could not be restored by an iridectomy. Formerly these
operations, although perfectly successful in a surgical sense — i.e. in so far
as the healing-in of the transplanted flap was concerned — with few excep-
tions, ended in disappointment, in conse j^uence of the flap not retaining its
transparency. But of late several successful cas3s have been recorded, in
which the flap remained clear.

The essential points to be attended to for a successful issue of the
operation are : — The flap must be taken from a human cornea. There
should be perfect asepsis. The membrane of Descemet must not be per-
forated, and the flap must be treated gently and not bruised by handling
with instruments.

The method of proceeding consists in removing, with a von Hippel
trephine, a disc of at least 5mm. in diameter, from the centre of the leucoma,
and inserting in its place a similar disc taken from a clear cornea. In

162 DISEASES OF THE ETE. [cha^. v.

order to avoid perforation of Descemet's membrane, the trephine is provided
with a guard by which the depth of the incision can be regulated. The
disc of cornea isolated by the trephine is dissected off by passing a Gra?fe's
or special bent knife in the incision and dividing the base of the flap with
the blade of the knife held parallel to tlie corneal surface. The flap is then
carried on the blade to the defect prepared for it in the leucoma. It may
be very gently pressed into its place with a blunt probe. A bandage is
applied and is not removed for forty-eight hours.

The clear flap for transplantation may be obtained from a still-born
child, or sometimes even from the marginal portion of the cornea of the
leucomatous eye.

Magitot has shown that the tissues of an eye may be kept alive for
eight or fourteen days by preserving it at a constant temperature of 5° to
8° Centigrade (41° to 40° Falirenheit) immersed in hsemolysed serum ; the
serum must be human in the case of a human eye. He has also succeeded
in transplanting successfully a flap from a cornea preserved in this way
(Deferred Keratoplasty).

Lohlein has successfully performed the following operation for corneal
transplantation : — From the opaque cornea a rectangular flap 5 mm. in
width, extending from the upper to the lower margin, is removed. The
parallel boundaries of the flap are defmed with a fork-like instrument at
the end of each prong of which is a small circular knife, with which there
is but little danger of the cornea being perforated. At the upper end of
the double incision a short but thick conjunctival flap is dissected up.
This conjunctival flap is then seized with a forceps, which is of about its
own breadth, a Grsefe's cataract knife is passed behind it, and with short
strokes is made to enter the scleral tissue 8.t the limbus ; so that, along
with the conjunctival flap already formed, a narrow band of scleral tissue
is obtained. The forceps now seizes this scleral band, and the edge
of the knife is reversed, and, with sawing motions, is made to cut through
the substance of the cornea at the required depth, taking with it the flap
of corneal tissue originally delimitated. At the lower corneal margin a
narrow band of scleral tissue, and a short thick conjunctival flap are
formed by the knife in cutting out. The corneal flap is left in situ, while,
in a precisely similar manner, a similar flap is taken from the clear cornea
of an eye which is about to be excised. This second flap is then spread
out on the wounded surf ace in the fu'st ey» , the utmost pains being taken
that during the transfer the flap suffers not the slightest bruising or other
injury. The flap is fastened in its place by three or four points of suture at
either end, the needles being passed through the narrow bands of scleral
tissue, and the episcleral tissue of the eye. The conjunctival flaps are
spread over the sutures. Only warm normal sahne solution is to be used
for douching the field of operation.

Arcus Senilis (Gerontoxon). — This is a change which is developed
in the cornea without previous inflammation. It presents the
appearance of a greyish line all around and a little inside the margin
of the cornea. It commences and is always most marked above and

CttAf. v.] THE CORNEA. 163

below, never advancing farther towards its centre. It is more com-
mon in elderly people, bnt is sometimes seen in youth, and even in
childhood. No functional changes are caused by it, nor does it
interfere with the healing of a wound which may be made in that
part of the cornea. Arcus senilis is caused by a peculiar fatty
'degeneration of the corneal cells and fibrillae.

CHAPTER VI.
DISEASES OF THE SCLEROTIC.

The sclerotic or protective coat of the eye is continuous with the
substantia propria of the cornea. Its thinnest part is in the ciliary
region, hence when rupture occurs it is usually here. The anterior
ciliary vessels also perforate the sclera in this situation, and intra-
ocular growths make their way out along them.

Owing to its simple fibrous structure and poor vascular supply,
the sclerotic is not liable to many diseases. In fact it usually becomes
affected either from the subconjunctival tissue overlying it or from
the ciliary portion of the uveal tract.

In scleritis, as in conjunctivitis, iritis and keratitis, the white of
the eye becomes injected. But scleritis differs from conjuncti-
vitis, in the violet colour of the congestion, which is also ciliary
(Plate II. Fig. 5), in its restriction to certain areas of the circum-
corneal zone, and in the absence of secretion. From iritis, the
characteristic appearances, to be described later on, will readily
distinguish it.

Scleritis attacks only that part of the sclerotic which is anterior
to the equator of the eyeball, and it is either superficial or deep.
The superficial form is known as episcleritis. Yet it is not always
possible to distinguish between these two forms in a given case, as
the appearances in the early stages are very similar. They are
probably only different degrees of the same disease. But the neces-
sity of admitting the existence of two forms depends upon the different
course they each take ; the superficial form being a relatively harm-
less disease, while the deep form entails serious consequences.

Episcleritis. — Of this two kinds are recognised : — 1. Periodic
Transient Episcleritis (Fuchs), or Hot Eye (Hutchinson). 2. Epi-
scleritis of the usual type.

Periodic Transient Episcleritis is characterised by frequently recurring
attacks of inflammation of the episcleral connective tissue, giving rise to

164

CHAP. VI.] THE SCLEROTIC. 165

a vascular injection of a violet hue, but without any catarrhal or other
secretion, or any hard infiltration, as in episcleritis of the usual type.
It rarely attacks the whole sclerotic at one time, but is commonly confined
to a quadrant or more, and wanders from one place to another. When
the attack subsides, there is no stain left. The attack may be confined
to one eye, or it may be in both, or it may affect sometimes one eye and
sometimes the other. Pain, lacrimation, and photophobia are present in
varjdng degrees. Sometimes the eyelids are swollen. Occasionally the
iris and ciliary body become inflamed, and also the cellular tissue of
the orbit, with resulting exophthalmos. The attacks last from one or
two days to several weeks, and may recur once or twice a year and at
intervals of only two or three weeks. Patients are usually liable to the
disease for several years of their life. It attacks adults of middle age
for the most part. Some assign gout as the cause ; while others do not
find any symptoms of that diathesis in their patients. Rheumatism and
malaria seem sometimes to produce it, and some observers hold that
episcleritis and scleritis are frequently of tubercular or of syphilitic origin.
It is probable, too, that it may be caused by a gonococcus toxaemia, even
long after the primary disease has been cured.

Treatment. — The long continuance of most of the cases shows that
treatment has but little influence over the disease. Quinine and salicylate
of soda internally are the remedies likely to be of use, with local warm
fomentations, dionine, and a protective dressing during an attack.

Episcleritis of the usual type. This appears as a circumscribed
purplish, rather than red, spot (Plate II. Fig. 5), close to, or 2 to 3 mm.
removed from, the corneal margin. It is often unattended by
pain, unless when the eye is exposed to irritating causes, and need
not be elevated above the level of the sclerotic ; but in severe
cases there is a decided node at the affected place, with more or
less pronounced pain, which is increased on pressure. All the
symptoms disappear in the course of a few weeks, and reappear
at an adjoining place ; and in this way, in time, the whole circum-
ference of the sclerotic will have been attacked. The duration of
the affection is usually long ; and, in those instances where the
entire sclerotic becomes affected by degrees, the process may last
for years, on and off. Both eyes are often affected. The disease
is liable to leave behind it a dusky discoloration of the sclerotic
where each node was seated, but otherwise no harm to the eye
ensues. The patient should, as soon as possible, be informed of
the tedious nature of the affection. Very mild attacks of episcleritis
will be met with, which pass away in a few days, and do not recur.

Causes. — The affection is often of gouty or rheumatic origin.
It occurs sometimes in persons of tubercular or syphilitic constitu-

166 DISEASES OF THE EYE. [chap. vi.

tion ; and it is more frequent in senior adults than in children or
young people, and more commonly attacks women than men.

Treatment. — Local treatment should be confined to protection
with dressing and bandage, warm fomentations, and dionine. In
addition to these, massage should be used, if there be not too great
tenderness on pressure. Leeching at the external canthus is of
use when the pain is severe. As regards internal remedies, where
a syphilitic taint is present, mercury should be employed ; if struma,
cod-liver oil, maltine, etc. ; or if, as is most frequently the case,
rheumatism be the source of the evil, large doses of salicylate of
sodium (say 20 grains four times a day) will often be found to act
well. Salicylate of lithium is recommended in preference to the
sodium salt by some. Iodide of potassium in large doses (20 grains
four times a day, or more frequently) is a useful remedy in some
cases of this obstinate disease.

Deep Scleritis. — Here the whole of the anterior part of the sclerotic
is more likely to be affected than in the milder forms ; although
cases often enough occur where only an isolated node is present at
one time.

The progress of the case alone can render the diagnosis between
this and the milder forms certain, and hence the importance of a
guarded prognosis in the early stages of every case of scleritis.
The chief characteristics of deep scleritis are : — 1. Localised conges-
tion and swelling, with the appearance of yellowish nodules, which
do not as a rule soften or caseate. 2. Discoloration of the sclera.
3. Sclerotising opacities of the cornea. 4. Frequent relapses. In
this deep form changes — thinning and softening — of the scleral tissue
take place, which render the latter less resistant, and consequently
dispose it to become ectasied even by normal intra-ocular tension.
The result of this is a bulging (staphyloma) of the anterior part of
the eyeball (p. 171). This bulging produces myopia, and has a
deleterious effect upon the sight ; but, at a later period, vision is
often wholly destroyed by secondary glaucoma. It may happen
that the thinning, etc., of the sclerotic affects only a portion, and
not the whole, of the anterior surface ; and in such a case the
resulting staphyloma will be confined to that part of the sclerotic.
A staphyloma, whether total or partial, presents a bluish-grey
appearance, due to the uveal tract shining through the thinned
sclerotic.

CHAP. VI.] THE SCLEROTIC. 167

In deep scleritis, either with or without staphylomatous changes,
the process often extends some distance into the deep layers of
the cornea, giving rise to sclerotising opacity (Plate II. Fig. 5).
Iritis, punctate deposits on the back of the cornea indicating cyclitis,
chorioiditis, and opacity of the vitreous humour are not uncommon
complications, especially in strumous subjects.

Causes. — Young adults are the most common subjects of deep
scleritis, and it attacks females more often than males. Syphilis,
congenital or acquired, rheumatism, gout, tubercle, and disturbances
of menstruation are the most common assignable causes, but it
is probable there are others which are as yet undefined.

Treatment. — There are few diseases less amenable to treatment.
When any definite cause can be assumed to be present, the remedy
suitable to it is of course indicated. Besides this, a dressing of a
thick layer of cotton wool to be constantly worn when only one
eye is affected, warm fomentations, dionine, dry cupping on the
temple, or the artificial leech, complete rest of the eyes, and protec-
tion with dark glasses are to be recommended.

When all acute inflammation has passed away, an iridectomy
is sometimes indicated — either for optical purposes, when the pupil
is obstructed by corneal opacity, or for the purpose of reducing
glaucomatous tension, or of diminishing a staphyloma.

Syphilitic Gumma of the Sclerotic. — This is rare. The diagnosis
depends to a great extent on the history and co-existing signs of syphilis.
The appearance usually presented is that of one or more rounded tumours,
of sizes which may vary from that of a pea to that of a hazel nut. These
tumours are covered with a highly injected conjunctiva, through which
the yellowish colour of the gummata shines. They are seated close to
the corneal margin — and, consequently, give rise to opacity in the neigh-
bouring sector of the latter — but may extend as far as the equator, or
even farther back. As a rule there is much pain in the eye and head.
Iritis, retinitis, and vitreous opacities may form complications. In
advanced stages the sclerotic may be perforated, or become staphy-
lomatous, and the gumma may extend to the interior of the eye, producing
detachment of the retina, and atrophy of the eyeball.

Treatment. — In the early stages, an energetic inercurial treatment is
capable of producing such perfect cures, that not even a slight discolora-
tion of the sclerotic remains.

Tubercle of the Sclerotic. — Apart from those cases of more or less
diffused episcleritis and scleritis w^hich may be due to tubercle, primary
tubercle of the sclerotic sometimes occurs as a solitary nodule which may
ulcerate. We have seen such a nodule near the corneal margin (Fig. 68).
It measured 4 mm. at its base, and towards its apex was of a pearly white

108 DISEASES OF THE EYE. [chap. vi.

colour, while the vessels of the conjunctiva covering it were much injected.

The abscess was incised, and the cavity in the substance of the sclerotic

thoroughly curetted, after which a rapid cure took place. Examination

of the contents of the abscess demonstrated

the presence of the tubercle bacillus.

But in the majority of cases of tubercle of
the sclerotic, the disease is an extension from
the root of the iris, or from the ciliary body,
where it has had its primary seat. Gradually
the sclerotic becomes thinned by the tubercular
disease, staphyloma forms, and finally rupture
Fig. 68. may take place. In these cases, if the disease

be not too advanced, treatment with tuberculin
may be tried, but in later stages excision of the eyeball is indicated.

Brawny or Annular Scleritis is a rare disease, which occurs generally
in people over sixty years of age. It attacks the whole circumference of
the ciliary region in both eyes, and is characterised by rather flat brownish-
red gelatinous swellings, which may extend to the tendons of the recti
muscles. It is a very insidious and chronic disease. Evidences of intra-
ocular involvement, such as sclerosing keratitis, punctate deposits, posterior
synechia, vitreous opacity, and low tension, may be present. The sclera
is infiltrated with granulation tissue with numerous plasma cells, and
in some cases there is marked peri- and end-arteritis. The histology
points to syphilis as the cause. The Wasserman reaction proved positive
in a case of Verhoeff's, but negative in others.

Tumours of the Sclerotic, as primary growths, are exceedingly
rare ; but fibroma, sarcoma, and osteoma have been so observed.

Pigment Spots of a yellowish-brown colour are often seen in
the sclerotic close to the corneal margin. They are congenital,
and of no importance. Occasionally a black pigmented patch may
be associated with pigmented sarcoma of the ciliary region.

Injuries of the Sclerotic— Ruptures and perforating wounds are
those which have to be considered. Mere losses of substance may
be said not to occur.

The danger attendant upon a rupture or perforating wound of
the sclerotic — apart from the loss of the contents of the eyeball,
which is often associated with it — consists in the possibility of
infecting organisms being introduced into the interior of the eye,
and there setting up serious inflammatory reaction.

Ruftures of the Sclerotic are caused by blows on the eye, and are
often indirect.

A common cause of sclerotic ruptures amongst the agricultural
population is a blow from a cow's horn, while the animal is being

CHAP. VI.]

THE SCLEROTIC.

169

tied up or fed in the byre, and these cases are well known in oph-
thalmic hospitals. Blows with the fist produce similar injuries.
The lower and outer part of the orbit is the least prominent, and
therefore the eye is least protected here, and hence it is commonly
driven upwards and inwards by the blow, and the sclerotic usually
ruptures from 2 mm. to 5 mm. from the upper and inner margin of
the cornea, and concentrically with the latter. Often the conjunctiva
is not ruptured, but bridges over the opening in the sclerotic. Some
of the contents of the eyeball
may have been forced out
through the rupture — e.g. por-
tions of the uvea, iris, and ciliary
body, the vitreous, and the lens
(Fig. 69) ; and it is sometimes
difficult at first to ascertain the
exact state of affairs, by reason
of extra vasated blood in the an-
terior chamber, under the con-
junctiva, and in the tissues of
the eyelids.

Treatment. — When the con-
junctiva is not ruptured, it is
often advisable to confine treat-
ment to the application of a dressing, for the covering conjunctiva
acts as a protection against infection of the wound. Where serious
damage has not been done to the retina, fair or even good vision
may be regained in many of these cases, which at first sight seem
almost hopeless ; and, should perception of light be present, one
may reasonably conclude that the retina is not detached. When
the lens has been dislocated under the conjunctiva, — from whence
it can be removed, after the sclerotic opening has closed — the
patient will of course require a glass, as after cataract operation,
to aive him the best vision.

Fig. 69. — Rupture of the
sclerotic above the cornea, with sub-
conjunctival dislocation of the lens.

Small ruptures may occur, generally in young people, at the limbus
itself ; they are accompanied by tearing of the conjunctiva and usually
also by prolapse of the iris. Fuchs has also described incomplete ruptures
of the inner surface of the sclera ; some time after the injury an area
of conjunctival congestion is followed by a dark discoloration of the
sclerotic, towards which the pupil may be drawn, or the iris may even
be invisible at a point corresponding to the discoloration of the sclera.

170 DISEASES OF THE EYE. [chap, vi."

Perforating Wounds of the Sclerotic. — A large and gaping per-
forating wound is easily recognised. A portion of the chorioid,
ciliary body, or iris, according to the position of the wound, probably
lies in it, or part of the vitreous humour may be found in it ; while
the vitreous humour, as seen through the pupil, will be full of blood
(hsemophthalmos) , and blood may be present in the anterior chamber
(hyphaema, vtto, under ; ali^a, hlood), especially if the wound be far
forwards. Small wounds may be concealed by sub-conjunctival
haemorrhage, and here reduced tension of the eyeball is sometimes
a valuable diagnostic sign.

When inflammatory reaction follows upon one of these injuries
it may be either of the purulent or plastic form. In the former case
all the contents of the eyeball take part in the suppuration, and we
term it panophthalmitis, phthisis bulbi being its ultimate result.
In the plastic form, the iris and ciliary body alone are implicated, and
sight is slowly lost ; the eye here, too, becoming phthisical. Of the
two, the latter process is the more serious, as it is prone to give rise
to sympathetic ophthalmitis — a danger w^hich is not associated w4th
the eye lost through panophthalmitis.

Where the wound has been produced by a small foreign body,
which has remained in the interior of the eye, the position is much
more serious, and this subject will be discussed in chap. xi.

Treatment. — A clean-cut perforating wound of the sclerotic may
heal without inflammatory reaction, even when portions of the
uveal tract or vitreous humour are prolapsed into it, these prolapsed
parts becoming incarcerated in the cicatrix. In cases where the
wound is small (say less than 3 mm.), no suture need be used : a
carefully applied dressing and bandage will be sufficient to promote
the natural tendency to healing. But, where the wound is large and
gaping, any prolapsed chorioid, etc., must be freely irrigated with
sublimate lotion, 1 to 5000, and completely reduced — or if the pro-
lapsed parts, or portion of them, cannot be reduced, they must be
abscised — and the margins of the wound drawn together by a few
points of fine silk suture passed through part of the thickness of
the sclerotic ; or, the sutures may be passed through the conjunctiva
at some distance from the edges of the wound, the traction on the
conjunctiva being often sufficient to close the scleral wound. A
dressing is applied to each eye, and the patient is confined to bed.

But, if the injury be such — very gaping wound, much loss of

•CHAP. VI.]

THE SCLEROTIC.

171

contents of the eyeball, or extensive intra-ocular h?emori'liage — as
to render restoration of useful sight, or at least retention of the
shape of the eyeball, beyond reasonable hope, it is wiser to remove
the eyeball at once, rather than to run the risk of sympathetic
ophthalmitis without compensating advantage.

Staphyloma of the Sclerotic. — The sclerotic may become ectasied
(stapliylomatous) either uniformly or in the form of localised bulgings.
The most common condition under which we see a uniform stretching
of the membrane is in myopia, where the posterior pole of the eyeball
and its . neighbourhood become distended as will be described in
chap. xvi. In buphthalmos the whole sclerotic is stretched and
the cornea participates in the distension (chap. ix.). Localised
staphylomata of the sclerotic occur only in the anterior segment
of the eyeball, and are due to thinning, and consequent diminished
resistance, so that the affected part can no longer withstand the
normal intra-ocular pressure. This thinning is the result of deep
scleritis (p. 166), gummata, or tubercular disease. After a time,
high intra-ocular tension — brought on by closure of the angle of the
anterior chamber, resulting from the distortion of the eyeball, or
from complete ring synechise (p. 175) in cases complicated with
iritis — may become a second factor in the process.

These ectasies or staphylomata are of a bluish-black colour,

owing to the uvea, or the atro-
phied remains of it, shining

through the thin layer of sclerotic.

The staphylomata occupy either

the equator of the eyeball near

the insertions of the muscles

(equatorial staphyloma), or they

are situated in the portion of the

sclerotic close to the cornea,

where it is lined by the ciliary

body (anterior or ciliary staphy-
loma) (Fig. 70). The former can

be observed only when the eye is

turned well over to the opposite

side. The anterior staphylomata

may also be single or multiple,

and in the latter case they may become confluent and extend all

Fig. 70. — Anterior or ciliary
staphyloma of the sclerotic. Cup-
ping of the optic disc due to high
tension.

172 DISEASES OF THE EYE. [chap. vi.

round the cornea. A variety of the anterior staphyloma is termed
intercalary staphyloma, to indicate that it has its origin in the
narrow space between the ciliary body and the root of the iris.

Treatment. — For equatorial and anterior staphyloma, if the
tension of the eye be high, an iridectomy, if it can be performed,
is indicated, and by means of it the progress of the distension may
be arrested, and vision preserved. Should an iridectomy be im-
practicable, excision of the eyeball will often have to be advised for
the relief of pain, which is sometimes present, or to get rid of the
inconvenience caused by the large size of the eyeball, or on aesthetic
grounds.

Congenital Defects of the Sclerotic. Coloboma. — This forms an ectasy
of the sclerotic commencing below the posterior pole of the eye, and
extending forwards towards the ciliary region. It is accompanied by
coloboma of the chorioid, and sometimes of the iris and lens as well, and
is due to imperfect closure of the chorioidal fissure.

Blue Sclerotics. — In this condition, which is hereditary, and has been
met with in four generations, a light blue (azure) discoloration of the
sclerotic is frequently associated with fragilitas ossium. Inherited
syphilis was present in some of the cases.

CHAPTER VII.
DISEASES OF THE UVEAL TRACT.

Inflammations.

The iris, ciliary body, and cliorioid ^ together form the uveal tract.
If it be remembered that they closely resemble each other histologi-
cally, that their blood supply is identical, and that they form with
each other a continuous membrane, it is a matter of surprise that any
one of these three divisions of the uveal tract can undergo inflamma-
tion while the others remain healthy. Yet this is by no means
uncommonly the case. But it is more common for at least two of
them, and especially the iris and ciliary body, to be simultaneously
inflamed {irido-cyclitis) ; and the entire uveal tract may be affected
at one time {irido-chorioiditis — by which term it is implied, not only
that the iris and the chorioid are diseased, but also the intervening
portion of the tract, the ciliary body). If all three portions be
affected, one of them may be much more affected than either of the
others. Or, commencing in one portion, the inflammatory process
often spreads to one or both of the other portions.

It is convenient, in a systematic consideration of inflammation
of the uveal tract, to discuss it under the separate headings of iritis,
cyclitis, and chorioiditis.

Inflammation of the Iris. Iritis. — Iritis is acute or chronic.
It may also be primary or secondary. In primary iritis, the in-
flammation begins in the iris itself, and is not a result of some other
diseased process in the eye. Secondary iritis may be caused by
disease of the cornea or sclerotic, or by the swelling of an injured
lens, the presence of an intra-ocular tumour, detached retina, etc.

Acute Iritis. — The Objective Signs of Acute Primary Iritis, more
or less marked according to the severity of the case, are : — {a) loss

^ XopioVf the chorion ; hence chorioid, like the chorion.
173

174 DISEASES OF THE EYE. [chap. vil.

of lustre and of distinctness of pattern of the iris ; (b) change in
colour of the iris ; (c) functional disturbances (impaired mobility)
of the iris ; (d) contraction of the pupil ; [e) circumcorneal injection
of the ciliary vessels.

(a) The loss of lustre and of distinctness of pattern is due to
exudation in the substance of the iris and on its surface, and to
cloudiness of the aqueous humour through which the iris is seen —
caused by inflammatory products held in suspension — and often,
also, to some cloudiness of the cornea, (b) The change in colour
is due to hyperaemia of the iris, as well as to the presence of the
inflammatory products ; a blue iris becomes greenish, a brown iris
yellowish, (c) The impaired mobility, and the {d) contracted pupil,
are due to hyper?emia, to spasm of the sphincter iridis, and to
posterior synechiae. (e) The circumcorneal, or ciHary, injection
(Plate II. Fig. 2) is due to engorgement of the episcleral branches of
the anterior ciliary arteries which supply the iris.

Exudation of inflammatory products is present, in greater or less
degree, on either surface of the iris, and in its stroma ; in the pupil,
or rather on the anterior capsule of the lens in the pupillary area,
and — when, as so often happens, cyclitis is associated with iritis — in
the aqueous humour, and on the posterior surface of the cornea.
As a consequence of the exudation in and on the iris, in addition to
change in colour, and loss of pattern, the iris is often slightly
swollen.

Posterior synechise ^ — i.e. adhesions between the iris and the
anterior capsule of the lens (Plate II. Fig. 2) — occur as a result
of inflammatory exudation on the posterior surface of the iris, or
on its pupillary margin. The presence of posterior synechise is
ascertained by observing the play of the pupil when the eye is
placed alternately in strong light and in deep shadow, or by
observing the effect of a drop of atropine solution on the pupil, the
latter dilating only at those places where there are no synechise.
The pupillary margin may be adherent at one or two points only ;
or there may be broad synechiae occupying at least a fourth, or a
third, or even more of the margin of the pupil ; or there may be
both small and broad synechiae present ; or, finally, the entire
margin of the pupil may be adherent. If the entire pupillary margin

^ crovex^Xv, to hind together.

CHAP, vii.l THE UVEAL TRACT. 175

have become adherent, the condition is termed complete posterior
synechia (or circular posterior synechia, ring synechia, or exclusion
of the pupil) ; and in such cases, especially if of some standing,
atropine has no effect on the pupil. When complete posterior
synechia has developed, the iris after a time becomes bulged for-
wards like the sail of a ship in the wind, by reason of accumulation
behind it of aqueous humour, which now cannot escape into the
anterior chamber, and this condition is known as iris bombe ; it
is very liable to cause high tension of the eye (Secondary Glaucoma).

If the area of the pupil be filled with exudation — lying on the
anterior capsule of the lens — circular synechia being usually also
present, the condition is known as occlusion of the pupil.

Total posterior synechia is that condition in which the whole
posterior surface of the iris is adherent to the capsule of the lens.
It is rarely the result of ordinary iritis, but is seen frequently in
sympathetic ophthalmitis.

Exudation of inflammatory products into the anterior chamber
causes turbidity of the aqueous humour, and sometimes these
products sink to the bottom of the chamber and form a pseudo-
hypopyon. In some rare cases, the exudation in the anterior
chamber takes the form of a jelly-like mass, which may resemble
a dislocated crystalline lens. On the posterior surface of the cornea,
in some instances, exudation fastens itself as punctate deposits
(so-called keratitis punctata), and these, and turbidity of the aqueous
humour, indicate that the ciliary processes are involved in the
inflammation.

The Subjective Symftoms of Acute Primary Iritis are : — {a) pain,
(6) lacrimation and photophobia, (c) and dimness of vision, {a) The
pain is due to irritation of the ciliary nerves in the inflamed part.
Yet this pain is not always so much in the eye itself, as in the brow
over it, in the corresponding side of the nose, and in the malar
bone, and may extend to the whole side of the head. It varies in
its intensity and is often more severe at night. Some forms of
iritis are usually attended by much pain, while others are free from
it. (6) The lacrimation and photophobia are reflex effects from
irritation of the fifth nerve, they are often absent, and are rarely
present to such a degree as in some corneal affections, (c) The
dimness of vision is due to one or other or to all of the following : — ■
turbidity of the aqueous humour, punctate deposits on the posterior

176 DISEASES OF THE EYE. [chap. vlt.

surface of the cornea, exudation of lymph on the pupillary area of
the anterior capsule of the lens, opacities in the vitreous humour.

A gTave mistake into which beginners often fall is to take a case
of iritis to be one of conjunctivitis or scleritis (see pp. 46 and 164),
the " redness of the white of the eye " being that which misleads.
The appearance of the iris itself — normal, or exhibiting the signs
of iritis — will chiefly assist in the diagnosis. Moreover, the pain
in iritis is of neuralgic character, but in conjunctivitis, if there
be any pain, it is similar to that caused by a foreign body in the
conjunctival sac. In iritis there is no discharge, while in conjunc-
tivitis the eyelids are gummed in the morning by muco-purulent
secretion. The vascular injection in iritis is of the pericorneal
ciliary vessels, but in conjunctivitis of the conjunctival vessels
(Plate II.). In iritis, however, it often happens that there is con-
junctival as well as ciliary injection. But, as already stated, the
appearance of the iris itself is the most valuable guide in the diagnosis.
Look at the iris. If the opposite eye be healthy, compare the iris in
the affected eye tvith that in the healthy eye. These are important
precepts in the diagnosis of iritis.

Clinically we cannot always know whether only one or more than
one division of the uveal tract is in a state of inflammation. This
uncertainty is particularly liable to arise when there is severe .acute
iritis ; for then the symptoms present might all be derived from the
inflammation of the iris alone, while the contracted and obscured
pupil, opacity in the aqueous humour and cornea, and irritability
of the eye, render impossible a diagnosis of chorioiditis by the
ophthalmoscope ; and, whether in health or disease, the position of
the ciliary body puts it always out of reach of ophthalmoscopic
examination. Yet it may be taken for granted, that in every
severe case of iritis, particularly in those of syphilitic origin, more or
less cyclitis is also present ; while a deep anterior chamber, diminished
tension, tenderness on pressure, or punctate deposits on the posterior
surface of the cornea increase the suspicion. In most cases of very
slight iritis there is probably no cyclitis.

It is only after the acute inflammatory symptoms have subsided,
and the pupil has become clear, that disseminated changes in the
chorioid, opacities in the vitreous humour, and even retinitis and
optic neuritis, which may lead to optic atrophy, can be discovered,
with their corresponding depreciation of vision.

CHAP, vii.i THE UVEAL TRAC1\ 177

Etiology of Acute Primary Iritis. — The most common cause by
far of acute primary iritis is syphilis, pro])al)ly 50 per cent, of
the cases being due to it. Other causes are gonorrhoea, tubercle,
rheumatism, diabetes, enteric fever, pneumonia, influenza.

Syphilitic Iritis. — It is usually in the secondary stage of
acquired syphilis, along with, or following on, the papular skin
eruption, that one sees iritis ; and, in the majority of cases, there
is no characteristic appearance to indicate its specific nature, this
diagnosis depending upon the general history, or on the presence
of other signs of syphilis. The plastic inflammatory exudation
is present mainly on the surface of the iris, and along the pupillary
margin, and often also in the pupil. Posterior synechiae always
form, and it is occasionally in these cases that the gelatinous exuda-
tion in the anterior chambers mentioned above is seen. The cir-
cumcorneal injection is generally well marked, sometimes causing
elevation of the limbus of the conjunctiva, and even general,
although slight, chemosis. The degree of irritation (pain, photo-
phobia, and lacrimation) varies considerably, and is often slight,
even where the appearances in the iris are well marked.

Late in the secondary stage of syphilis, or within a year or so
after the primary infection, a form of iritis may occur which can,
indeed, be recognised as syphilitic. It is characterised by the forma-
tion of circumscribed nodules, or small condylomata, of a yellowish-
red colour, the rest of the iris being apparently intact (Plate II.
Fig. 2). These nodules vary in size from that of a hemp-seed to
that of a small pea, and are situated usually at the pupillary margin,
occasionally at the periphery of the iris, and very rarely in the body
of the iris. There may be but one nodule present, and there are
seldom more than three or four. This form is not common.

Occasionally iritis occurs in the tertiary stage of syphilis, and
then sometimes with the formation of inflammatory tumours in
the iris, which are to be regarded as gummata.

In inherited syphilis, iritis does sometimes occur without inter-
stitial keratitis (p. 137), but is more frequently seen in conjunction
with the latter. Childhood and youth are the periods of life in
which it is observed. In doubtful cases Wasserman's test or the
Luetin test may be used.

GoNORRHCEAL Iritis. — This is not uncommon, and probably
many cases of iritis reckoned as rheumatic are in fact due to gonor-
12

178 Di:^EASES OF THE EYE. [chai\ vii.

rhoea. The appearances are very similar to those of the iritis which
occurs in secondary syphilis, but punctate deposits on the posterior
surface of the cornea are more common in the gonorrhoeal cases.
Iritis does not attend on, nor immediately follow, a gonorrhoea ;
but an attack of gonorrhoeal arthritis, usually of the knees, always
intervenes, and the interval between the attack of arthritis and the
attack of iritis may be very lengthened — extending even to years.

Tubercular Iritis. — Tubercle occurs in the iris in three forms ;
of these, one, the conglomerate or solitary tubercle of the iris, will
be described under the heading of New Growths of the Iris. It is
not usually associated with iritis. The other forms are properly
regarded as tubercular iritis. They are : —

a. Very fine miliary nodules which occur in the iris, chiefly
at the angle of the anterior chamber, or near the pupillary margin,
where they give rise to posterior synechise. They are of a yellowish-
grey colour, or, by reason of vessels which may form in them, they
may be reddish, or cinnamon coloured. There is some iritis, and
often, also, punctate deposits on the back of the cornea indicating
engagement of the ciliary body. The process runs a sluggish course,
and is not painful ; the nodules increase in size slowly, then cease to
grow, become smaller, and finally disappear. This form of tubercular
iritis has been termed by Leber attenuated tuberculosis of the iris,
and its prognosis is favourable, although some derangement of sight
may remain as a result of the iritis. The disease is often binocular.

h. The second, and more common, form of disseminated tuber-
culosis of the iris is also associated with iritis, accompanied with
much ciliary injection. But in this form, along with small nodules,
there are some of larger size — so large, sometimes, as to touch the
back of the cornea. They are of a pale buff colour, and may be
scattered over the whole iris, although their seat of election — a
rather important point for the diagnosis — is the angle of the anterior
chamber. This form is frequently, and in our experience commonly,
associated with tubercular disease of the true cornea (tubercular
kerato-iritis), which is manifested by a diffuse haze in the deep
layers of the cornea, and by the presence, in the same layers, of
scattered small and large greyish-yellow infiltrations, each of them
surrounded by a less intense halo. A vascular network, derived
from the deep marginal vessels, forms about these corneal infiltrations.
Punctate deposits are present on the back of the cornea, and the

CHAP. VII.] THE UVEAL TRACT. 179

aqueous humour may be hazy ; and if the vitreous humour can be
examined, it, too, may be found more or less opaque. This form
usually goes on to complete loss of sight if untreated. At a late
period, the growth of tubercle ceases, and the shape of the eyeball,
with more or less opaque cornea, may be retained ; or caseation,
followed by phthisis bulbi, may result. One or both eyes may be
attacked. Pain is not a prominent symptom — in many cases there
is none.

The diagnosis of tuberculosis of the iris cannot be made off-hand
from the presence of nodules in the iris, as nodules occur in other
forms of iritis, notably in some cases of syphilitic iritis. The
syphilitic condyloma is of a yellowish-red, while the tubercular
nodule is of a greyish-red or of a buff colour, and often presents a
somewhat translucent appearance. Those cases of nodular iritis which
are accompanied by infiltrations in the deep layers of the cornea, as
above described, can be regarded with great certainty as tubercular.
But the history of the patient— exclusion of syphilis, acquired or
congenital — his present state as regards tubercle elsewhere in the
system, and the family history as to tubercle must be investigated.
As tubercle of the iris commonly occurs in childhood or in early
youth, the exclusion of acquired syphilis is not often difficult, and
the presence or absence of the stigmata of congenital syphilis decides
the diagnosis in that respect. In leprosy, leucaemia, and in pseudo-
leucaemia, iritis with formation of nodules occurs, and also in those
rare conditions ophthalmia nodosa (p. 86) and sporotrichosis.

Signs of former, or of existing, tubercular disease elsewhere in the
body are obviously of great value for the diagnosis, for intra-ocular
tuberculosis is alw^ays a secondary or metastatic condition, the
primary focus being elsewhere in the system. Should no such focus
be found, it must be remembered that it is possible for a small
tubercular deposit to be present in the body, which may cause no
symptom, and w^hich may escape detection by physical examination ;
in short, intra-ocular tuberculosis, although not the primary focus,
may be the first indication of tubercular infection.

The microscopical examination of a portion of the iris removed
by iridectomy is conclusive for the diagnosis, if tubercle bacilli can
be found in it, but this is rarely so. An inoculation experiment, by
the insertion of a portion of the iris into the anterior chamber of
a guinea-pig's eye, gives a more certain result. Neither of these

180 DISEASES OF THE EYE. [chap. vii.

measures, however, is admissible, as iridectomy is liable to cause
the iritis to take on renewed activity. The aqueous humour may
be drawn off with a fine hypodermic syringe, and injected into the
anterior chamber of a guinea-pig's eye, where it gives rise to tuber-
cular iritis if tubercle bacilli be present, which is not always the
case. This proceeding is harmless.

Finally, for diagnostic purposes a hypodermic injection of
tuberculin may be used. Of Koch's old tuberculin a dose of 1 m.gr.
of the dry substance is injected. If the disease be tubercular, a
sudden and decided rise of temperature may take place, and as
rapidly subside ; and occasionally there is a passing local reaction
in the eye. If there be no increase of temperature, a double dose
is giv^n the next day but one. But if there have been a slight
elevation of temperature, even if it be only J degree, the dose is not
increased, and after the temperature has again become quite normal,
the same dose is repeated. It will often be noted that the second
reaction which now occurs — although the dose is the same — is more
marked than the first. This, in Koch's opinion, is an exceedingly
characteristic occurrence, and may be taken as an unfailing sign of
the presence of tuberculosis. But if no reaction follows on the low
doses, then a dose of 5 m.gr. and finally, if necessary, one of 10 m.gr.
is given, or, to make quite sure, this last dose may be repeated. If
then there be no reaction, the presence of tubercle may be excluded.
The reaction may be looked for in from twelve to eighteen hours
after the injection. This method is the one we employ. Von
Pirquet's Cuti-Eeaction may be employed.

Rheumatic Iritis. — This is usually of the form which is common
in the early secondary stage of syphilis (p. 177), but it is accom-
panied by circumcoxneal injection, which is great in proportion to
the other signs of iritis present. The pain is often peculiarly severe,
and again the attack may be painless. Iritis is not found in associa-
tion with acute rheumatic arthritis, but rather with the sub-acute
articular rheumatism, which attacks now one joint and again another
through several months of the year, in the winter and spring. Rheu-
matic iritis is very liable to recur.

Treatment of Acute Primary Iritis. — A mydriatic is in all cases
the most important means. Most commonly a solution of atropine
(Atrop. sulph. gr. iv., Aq. dest. §j) is used as eye-drops. An atom of
sulphate of atropine in substance, placed in the conjunctival sac,

CHAP, vir.] THE UVEAL TRACT. 181

gives a very pronounced reaction. It is also used in the form of
ointment (Atrop. sulph. gr. iv., vaselin §j), and in gelatine discs.

By paralysing the sphincter iridis, atropine provides rest for the
inflamed iris ; and, if adhesions have already formed, the dilatation
of the pupil may break them down, while if none be as yet present,
the dilatation will greatly aid in preventing their formation. Again,
owing to diminished volume of the iris, its vessels contain less blood,
and the hyperasmia of the inflamed part is reduced. Yet in cases
of irido-cyclitis, where the cyclitis is the prominent factor, atropine
does not always promote the cure, for by depleting the vessels of the
iris it engorges those of the ciliary body.

To produce a maximum effect on the pupil, where it is desired
to break down adhesions, six drops of the atropine solution should
be instilled into the eye, with an interval of from five to ten minutes
between each ; and in this way the atropine from each drop has time
to make its way into the anterior chamber, and finally the accumu-
lated effect of all six is obtained. More than one drop can hardly be
retained in the conjunctival sac at a time. The use of cocaine
(2 per cent.) along with atropine ensures a maximum dilatation. A
drop of the atropine solution into the eye from once or twice to four
times a day is required, in order to maintain the desired dilatation
of the pupil ad maximum, in a severe case.

Some individuals are peculiarly susceptible to atropine poisoning,
of which the symptoms are : — dryness of the throat, fever, fullness
in the head, headache, delirium, coma. The antidote is morphia, of
which J grain used hypodermically neutralises -Jg- grain of atropine
in the system. Atropine poisoning can occur by the introduction
of the solution into the stomach through the lacrimal canaliculi,
nose, and fauces ; and to prevent this the finger of the patient may
be placed in the inner canthus, so as to occlude both canaliculi during,
and for some moments after, the introduction of the drop into
the eye.

After use of atropine in some persons the skin of the lower eyelid,
or of both eyelids, becomes eczematous, red, swollen, and painful ;
and in other cases after long use follicular conjunctivitis is induced.
If these complications occur, solution of scopolamine should be
substituted for atropine, and suitable remedies used for skin or con-
junctiva. Scopolamine solutions should not be stronger than J to J
per cent. We have seen very marked symptoms of poisoning

182 DISEASES OF THE EYE. [chap. vii.

follow the use of a 1 per cent solution, which was not prescribed
by us.

In old people tenesmus and retention of urine sometimes result
from use of atropine.

Atropine, while it is so useful in the treatment of inflammations
of the iris, ciliary body, and cornea, is of no benefit in many other
diseases of the eye, and is positively harmful in some of them. It
is necessary to make this statement very explicitly, for many medical
men, who have not devoted attention to the subject of eye-disease,
include atropine in every eye-lotion they prescribe. If the disease
prescribed for be conjunctivitis, the atropine is calculated rather to
increase than to relieve the conjunctival affection ; while, if the
patient be advanced in life, there is always the danger that a
tendency to glaucoma may be present, and in such a case the
dilatation of the pupil caused by the atropine will be sufficient to
bring on an attack of acute glaucoma. It falls to the lot of most
ophthalmic surgeons to be called, at one time or another, to a
case of acute glaucoma caused by the use of atropine in this
thoughtless manner.

Dark protection spectacles should be worn by patients suffering
from iritis ; and in severe cases, especially in cold weather, the eye
should be covered with a thick pad of cotton wool, and the patients
should be confined to a dark room, and even to bed.

Hot fomentations — every two hours for twenty minutes — are of
benefit in all forms of acute iritis, and they relieve pain. Dionine is
also useful in relieving pain, and seems to promote the cure. If the
pain be severe at night a hypodermic injection of morphia may be
given. Should there be much irritation, pericorneal injection, or
chemosis, leeching at the external canthus over the orbital margin
is of use. Occasional gentle purgatives are desirable. Blistering
on the temples, or behind the ear, has been a favourite item in the
treatment of iritis ; it adds to the annoyance of the patient, and
as a remedy it is valueless.

In addition to the foregoing measures which are applicable in
all cases, the special etiological moment must be considered in the
treatment of each case, as follows : —

Treatment of Syphilitic Iritis. — As it is important to obtain rapid
absorption of the inflammatory products so abundantly thrown out,
and which would soon cause extensive damage to the eye, the system

CHAP. VII.] THE UVEAL TRACT. 183

should be put under the influence of mercury as quickly as possible,
by the use of mercurial inunctions ; or by small doses of calomel
internally ; or by intra-muscular injections, 1 grain of metallic
mercury being injected once or twice a week in the form of a cream
made with lanolin as recommended by Lambkin. The reports
published of the effect of salvarsan in syphilitic iritis are very
favourable. When the acute symptoms have passed away, an
after treatment with iodide of potassium should be employed.^
In iritis due to congenital syphilis, mercury is not generally in-
dicated, but the syrup of the iodide of iron, and a general tonic
treatment is preferable. In cases of acquired syphilis, as there is a
marked tendency of iritis to relapse, it is important that, for some
weeks after the acute stage has passed, the pupil should be kept
under the influence of atropine, the eyes protected with dark glasses,
and the internal administration of iodide of potassium continued.

An attack of syphilitic iritis may last from two to eight weeks,
and cases which seem to be slight — i.e. where the pupil dilates well
and rapidly to atropine, and where but little lymph is thrown out —
sometimes cause disappointment by their slow recovery. It is
possible that an attack of iritis, if carefully treated from the begin-
ning, may leave the eye in as healthy a condition as before, but it
is more common, in spite of every effort, to find isolated posterior
synechise, or a circular synechia, left behind. The presence of a few
isolated synechiae, if the pupil be clear, is in itself harmless to sight ;
but, if relapse should take place, and fresh adhesions form, a
complete posterior synechia (p. 175) going on to iris bombe may
ultimately be established. Complete posterior synechia may of
course result from the first and only attack of iritis.

In some cases of iritis, the vitreous humour becomes more or
less opaque, and this condition does not always disappear as the
iritis gets well ; indeed, it may not be possible to ascertain its
presence until after the inflammatory process in the iris has
subsided. In these cases the ciliary body has participated in the
inflammation, although there may have been no punctate deposits
on the cornea. Again, there may have been some chorioiditis and
retinitis during the attack. Great and permanent deterioration of

1 Iodide of potassium must not be prescribed in conjunction with
treatment by injections of metallic mercury.

184 DISEASES OF THE EYE. [chap. vii.

vision may result from such complications ; and this emphasises the
importance of a cautious prognosis at the commencement.

In complete posterior synechia, after the acute iritis has sub-
sided, an iridectomy is indicated to restore communication between
the posterior and anterior chambers. For the treatment of opacities
in the vitreous humour see chap, xi., and of syphilitic chorio-retinitis
see chap. xii.

Treatment of Tubercular Iritis. — Cases of attenuated tuberculosis
of the iris simply require local treatment with atropine, hot fomenta-
tions, and protection spectacles.

In the treatment of the more j^ronounced form of tubercular
iritis, the tubercular infection must be combated, and the chief
therapeutic measure of value for this purpose is inoculation with
tuberculin. The method we employ at the Victoria Hospital is as
follows : —

The preparation used is Koch's Tubercle Bacilli Emulsion.
The patient's temperature having been ascertained to be normal, a
hypodermic injection of 1 c.c. of the ' fifth dilution,' representing
0*000005 m.g. of the bacillary substance, is given. The temperature
is taken every two hours, and if in the course of twenty-four hours
there be no reaction, an injection of 1 c.c. of the ' fourth dilution,'
equal to 0*00005 of the bacillary substance, is given. The dose is
thus gradually increased at intervals of one or two days, unless the
temperature be raised, until the original liquid is reached, 1 c.c. of
which contains 5 m.gr. of the substance. When the higher doses are
given, the intervals should be considerably longer, and if, after any
dose, a rise of temperature of 0*5 of a degree or more take place, the
previous dose is repeated, and an increased dose is not given until a
general reaction ceases to be caused. In the majority of cases treated
marked improvement became apparent within a few weeks, the
nodules in the iris becoming smaller and less vascularised, the deep-
seated corneal infiltrations thinner, the punctate deposits fewer,
and the eye less irritable and injected, until finally, with continued
treatment, all tubercular deposits and infection disappeared, leaving
only such permanent damage to the eye and sight — due to corneal
changes and pupillary occlusion — as may be proportional to the
duration and severity of the disease before treatment took effect.
The treatment is a protracted one, as long as six months, possibly,
being needed to effect cure in a severe case.

CHAP. VII.] THE UVEAL TRACT. 185

Valuable adjuncts in the treatment with tuberculin are local
hot fomentations, cod-liver oil, and syrup of the iodide of iron.

On the question as to whether an eye which is disorganised by
intra-ocular tuberculosis beyond hope of recovery should be excised,
opinions are divided. Were the eye the primary focus, excision
might be indicated in even a less advanced stage. But cases are
on record in which, soon after excision of a tubercular eyeball,
death from tubercular meningitis, or from acute miliary tuberculosis,
took place ; and which were therefore suggestive of dissemination
of the tubercle as direct result of the operation. We can offer no
experience of our own in this connection, but it would seem that
there is a risk in removing the eyeball in these cases. Where
excision is not undertaken, extension of the disease to the optic
nerve, and so to the brain, is exceedingly rare.

For Eheumatic Iritis the general treatment is the same— salicy-
late of soda, aspirin, etc. — which is found useful for rheumatic
symptoms in other parts of the body.

In Gonorrhoeal Iritis, too, treatment with salicylate of soda is
the most successful. Gonococcal vaccines have given good results
in the hands of several surgeons.

Chronic Iritis or Irido-Cyclitis.— In the mildest cases of chronic
iritis the only objective sign may be the presence of punctate deposits
on Descemet's membrane (so called Keratitis Punctata) with no
visible changes in the iris. This was formerly called Serous Iritis,
but is in fact a cyclitis. In other cases posterior synechia occur with
or without corneal deposits. In the severer cases, the stroma of the
iris is distinctly altered as regards colour and pattern, there are
abundant deposits on the back of the cornea, and opacities in the
vitreous humour. There is no pericorneal injection in chronic iritis,
or, at most, it is slight, occasional, and ephemeral.

The chief, or only, subjective symptom in chronic iritis is defective
vision, and this it is which brings the patient for advice ; for there
is little or no pain, photophobia, or lacrimation. On examination,
some of the above-mentioned objective signs are found, and inquiry
elicits the fact that, except for gradual failure of sight, the patient
has had little trouble beyond an occasional ' cold ' in the eye— i.^.
slight ciliary injection— which lasted a few hours, or a day or so at
a time, in the course of preceding years.

The slighter cases of this affection which are confined to the

186 DISEASES OF THE EYE. [chap. vii.

iris, and do not run a long course, may not cause serious loss of sight,
but, on the other hand, cases which begin as mild ones may, after
a few relapses, become converted into typically severe cases. The
more severe cases, accompanied by cyclitis and punctate deposits,
are liable to be complicated with high tension (secondary glaucoma),
owing to blocking of the angle of the anterior chamber with
exudation, which seriously endangers vision.

In the severest cases the whole uveal tract is involved, and
the term Chronic Uveitis becomes applicable to the condition.
The exudation of inflammatory products is very great, with the
following results : — marked punctate deposits — giving rise to paren-
chymatous opacity of the cornea — turbid aqueous, atrophy of the
iris, posterior synechiae going on to exclusion of the pupil, often
occlusion of the pupil, iris bombe, opacity of the vitreous humour,
cataract, atrophy of the chorioid and retina, high tension owing
to iris bombe, absolute blindness, staphyloma of the globe — or,
in the last stages, the eye may become phthisical instead of staphy-
lomatous. In some few cases iris bombe may not come on, and
complete blindness may not result, rendering the prospect of a
cataract extraction fairly good.

Pathogenesis. — Chronic Iritis and Chronic Uveitis frequently
occur, or rather commence, in youth, and are more common amongst
females than males. The severe cases may continue intermittently
for many years before complete blindness is reached. Syphilis
is not often a cause of chronic uveitis. Tubercle is now held to be
the cause in a certain proportion of the cases, and it is necessary
to give diagnostic injections of tuberculin to decide the diagnosis
(p. 180). Very strong evidence has been collected of late which
renders it tolerably certain that many of these cases are caused by
auto-infection arising from oral, intestinal, or genito-urinal sepsis,
and more rarely from septic conditions in other parts (furuncles,
etc.). Treatment by autogenous vaccines have in many cases proved
most beneficial and in some have produced a rapid cure. Affections
of the teeth, especially pyorrhoea alveolaris, may undoubtedly act as
a cause of chronic iritis ; only one or two teeth may be involved.

As an evidence of auto-intoxication from intestinal stasis indi-
canuria has been considered important by some authors, but it is
only one of the signs of intestinal putrefaction and it cannot be relied
upon as an indication of auto-infection.

CHAP. VII.] THE UVEAL TRACT. 187

Another, and a more difficult question, which cannot be discussed
here, is as to whether intestinal auto-iutoxication, not due to micro-
organisms, but to the formation of poisons from faulty metabolism,
can also be held responsible for a chronic iritis.

Treatment of Chronic Iritis and of Chronic Uveitis. — In addition
to the usual local measures — atropine, hot fomentations, dionine,
protective dressing — sub-conjunctival saline injections (p. 120)
are indicated. Paracentesis of the anterior chamber (p. 118) may
also be used with advantage, and can be repeated about once a
week. The hyperaemia of the uveal tract, which immediately
follows the operation, promotes the access of anti-bodies and other
healing substances to the diseased membrane.

If the disease be due to tubercle, a course of treatment with
tuberculin (p. 184), concurrently with the above local treatment,
is indicated. Or, if 'auto-infection be the cause, its source must be
ascertained, if possible, and vaccines, preferably autogenous, should
be tried. The organisms most commonly concerned are the strepto-
and staphylo-coccus and the pneumococcus. If necessary the
f?eces should be examined.

Inflammation of the Ciliary Body : Qyaliiis,— Acute CycUtis,
as has been stated, attends all cases of severe acute primary iritis,
and often many of the slighter cases, whatever be their etiology,
a fact which has been demonstrated by pathological examination.
Yet, very frequently, there are no clinical signs of its presence, or
they are masked by those of the iritis. The most common clinical
sign of cyclitis in these cases is fine punctate deposits — often so
fine as to be discernible only with the combined focal method, or
w4th the corneal microscope — on the back of the cornea, with, it
may be, slight turbidity of the aqueous humour, and occasionally
the formation of a small pseudo-hypopyon.

Owing to gravitation, these deposits are usually precipitated on
the lower quadrant of the cornea over a triangular area, the base
of which corresponds with the lower margin of the cornea, the
apex being directed towards the centre of the cornea, with the finer
dots near the apex. The triangular shape results from the motions
of the eyeball. In many cases, however, nearly the whole cornea is
more or less affected. Some of the larger spots present an opaque
yellowish-white appearance which has been compared to the ' mutton
fat ' drops which are found floating in cold mutton gravy.

188 DISEASES OF THE EYE. [chap. vii.

In cases where the punctate corneal deposits continue for a
length of time, permanent secondary changes in the true cornea
take place — in consequence of the resulting degeneration of the
endothelium on the posterior corneal surface — and a consequent
triangular opacity at the lower part of the cornea will ever after-
wards indicate the nature of the process which has gone before.

But cyclitis is sometimes seen without iritis. Its signs, in a
severe case, in addition to those above mentioned, are: — Marked
circumcorneal injection, pain on pressure of the ciliary region,
deep anterior chamber owing to hyper-secretion of the aqueous
humour or to retraction of the root of the iris, and oedema of the
upper lid. There is danger of increase of the intra-ocular tension,
owing to the tendency to blocking of the angle of the anterior chamber
with inflammatory exudation.

Cases which may begin as cyclitis soon show signs of iritis, and
follow the same course as those already described under the heading
Chronic Irido-Cyclitis.

Syphilitic Gumma of the Ciliary Body. — This is rare, and belongs
to the tertiary stage of syphiUs, although it is sometimes seen much
earlier. It is always preceded by acute irido-cyclitis of the usual plastic
type. It appears at first as a small circumscribed nodule with smooth
round surface slightly raised over the surface of the sclerotic in the ciliary
region. It sometimes increases in size very rapidly — and is then attended
by violent iritis and mvich pain — and again but slowly. It may attain
the size of a pea, or even of an almond, and may extend some way around
the cornea, presenting a reddish, yellowish, or bluish colour. After a
time, in the less severe cases, the gumma becomes smaller and disappears,
leaving a dark cicatrix in the sclerotic. But in other cases it breaks
through the sclerotic, although very rarely through the conjunctiva, by
destruction of tissue ; and when this has taken place the tumour grows
smaller and undergoes absorption, and the eye becomes phthisical. The
gumma may also grow into the anterior chamber, and but rarely into
the vitreous humour. The interval between the appearance of the gumma
and completion of the process is from a few days in the very acute cases,
to several weeks in the more chronic cases. The bulbar conjunctiva is
hyperaemic, and often chemotic. In the cornea there is generally a slight
diffuse opacity with stippling of the epithelium, and there may be posterior
punctate deposits.

The severe acute cases are accompanied by intense interstitial kera-
titis, oedema of the upper lid, and violent pain. The mildest cases may
end with retention of fair vision, but in most instances serious damage
to sight results ; while, in very many, vision is totally lost, and the eye
becomes phthisical. In many of the recorded cases the eye was excised
in the acute inflammatory stage on account of agonising pain.

Plate III.

L.W.

Fig. 1. Chorioido- Retinitis (Specific).

Fig. 2. Disseminated Chorioiditis.

PLATE III

{To face page 189)

Fig. 1. — Chorioido-Retinitis in an early stage. A central area of haziness
extends around the disc and macular region, rendering the outline
of the form indistinct, and concealing the retinal vessels in places.
The veins are somewhat engorged. Soft-edged yellowish white spots
of chorioidal exudation are visible farther out towards the periphery.
A retinal vein passes over one of these spots.

Fio. 2. — Chorioido-Retinitis in a later stage. The retinal haze has dis-
appeared. Irregular patches of atrophy of the chorioid are scattered
over the periphery, some of them bordered by pigment. Spots of
black pigment surrounded by a narrow yellow zone are also to be
seen. The chorioidal vessels are rendered visible close to the disc,
owing to atrophy of the pigment-epithelium.

onii

CHAP. VII.] THE UVEAL TRACT. 189

Tubercular Cyclitis. — This is frequently associated with tubercular
iritis, although its presence cannot be clinically detected. Yet in some
cases the disease in the ciHary body assumes the form of a large nodule,
or even a tumour of considerable size — or there may be more than one
of these — and causes staphylomatous bulging at the corneo-scleral margin,
which may go on to rupture externally.

Treatment of Cyclitis. — This follows very much the lines of the
treatment of iritis. Atropine, by paralysing the ciliary muscle,
acts favourably on the disease. On the other hand, if the pupil
be dilatable, atropine causes engorgement of the ciliary body by
the blood driven out of the iris. Consequently, its effect on the
symptoms must be watched, and it may become necessary to dispense
with its use, and even for a time to substitute a miotic. Hot fomen-
tations to the eye, and a warm bandage, and, in acute cases, leeching
at the external canthus are serviceable.

In chronic cyclitis sub-conjunctival injections of normal solution
of salt are indicated ; and, if the intra-ocular tension become high,
paracentesis of the anterior chamber should be performed.

In syphilitic gumma of the ciliary body an active mercurial
treatment is necessary. Salvarsan is very efTectual. In tubercular
disease, treatment with tuberculin affords the best prospect of cure.
* Inflammations of the Chorioid(xopioi/, ^/iec/iomn, hence chorioid,
like the chorion) . Inflammations of the chorioid are not accompanied
by any outward signs of congestion, or by pain except in purulent
cases, and hence their recognition depends on ophthalmoscopic
examination. There are two chief forms of inflammation of the
chorioid, the exudative, which is subacute or chronic and appears in
discrete patches or spots, and the purulent, which is acute and wide-
spread and generally involves the retina as well.

Both forms are caused by micro-organisms, or possibly by their
toxins, circulating in the blood. Some diseases to which the name
of chorioiditis is given are really degenerative affections. The
exudative form comprises disseminated chorioiditis, central chorioid-
itis, syphilitic and tubercular chorioiditis.

Disseminated Chorioiditis. — The usual Ophthalmoscopic Ap-
pearances of this disease (Plate III. Fig. 2) consist either in round
or irregular white spots or patches of different size with irregular
black margins, or in small spots of pigment, these changes being
surrounded by healthy chorioidal tissue ; or, there may be few or

190 DISEASES OF THE EYE. [chap. vii.

no white patches, but rather spots of pigment surrounded by a pale
margin. The retinal vessels are seen to pass over the patches.
The number of these patches or spots varies according to the
intensity of the disease. Their position is at first at the periphery
of the fundus only, but later on they appear also about the
posterior pole of the eye.

These appearances, however, represent a rather late stage of
the disease, the early stage coming but rarely under observation.
It consists in small circumscribed plastic exudations into the tissue
of the chorioid, which, if seen with the ophthalmoscope (Plate III.
Fig. 1), give the appearance of pale pinkish-yellow or greyish
spots behind the retinal vessels. These exudations may undergo
absorption, leaving the chorioid in a fairly healthy state ; but, more
usually, they give rise to atrophic cicatrices, in which the retina
becomes adherent, with proliferation of the pigment-epithelium
layer in their neighbourhood, and hence the white patches with
black margins above described. It is this form of chorioiditis which,
in its earliest stages, is often associated with inflammatory processes
in the iris or ciliary body, either as a primary or secondary affection.
But, again, in many instances the disease does not extend beyond
the chorioid.

Sometimes, in addition to the above changes, the pigment-
epithelium layer all over the fundus becomes atrophied, exposing
to view the vascular network of the chorioid, while here and there
small islands of pigment are present.

Opacities in the vitreous humour are sometimes found.

Symftoms. — Diminution in the visual acuity, especially if the
macula be involved. There also may be subjective sensations of
light or colours, positive scotomata (dark areas visible to the patient),
ring scotomata (Fig. 19) or sector-like defects, and distortion of
objects (metamorphopsia), or alteration in their size (megalopsia
and micropsia). Night-blindness is not uncommon.

Causes. — Disseminated chorioiditis is due to acquired syphilis
in a considerable number of the cases, while in some it is tuber-
cular. But in a very large proportion of cases no ascertainable
cause exists ; and these cases, there is reason to suspect, are con-
genital, and probably many of them are dependent on an inherited
syphilitic taint. In eyes with congenital cataract, patches of
chorioiditis are often found.

CHAP. VII.] THE WEAL TRACT, 191

Prognosis. — Disseminated chorioiditis is always a serious and
very chronic disease, fresh spots of exudation making their appear-
ance from time to time, and complete recovery cannot be looked or.
The degree of defect of sight it may cause in the early stages depends
much on the extent to which the region of the macula lutea has
been involved. In some cases, however, fair sight may be retained
for many years. In advanced cases the optic nerve and retina
become atrophied, and still later the lens becomes cataractous.

Treatment. — In fresh cases due to acquired syphilis, a prolonged
but mild course of mercurial inunctions or salvarsan are the most
suitable measures, to be followed by a lengthened course of treatment
with iodide of potassium. Where an inherited syphilitic taint is
suspected, iodide of iron or iodide of potassium internally may be of
use. Both in the acquired and congenital cases salvarsan will be of
service. If tuberculosis be the cause, a course of tuberculin inocula-
tions should be employed ; while, in the cases due to other causes,
small doses of perchloride of mercury may be given ; and in all
cases sub-conjunctival injections of 4 per cent, solution of common
salt are indicated. Dark protection spectacles should be worn,
and absolute rest of the eyes from all near work insisted upon, so
long as the disease is active.

CENTRAii Senile Guttate Chorioiditis. — This is a degenerative
disease which was first described by Waren Tay. It consists of fine
white, pale yellow, or glistening dots, best seen in the upright image,
and situated chiefly about the macular region, or between this and the
optic papilla. These dots are due to colloid degeneration with chalky
formations in the vitreous layer of the chorioid, which give rise to secondary
retinal changes. The appearances must not be confounded, as they
sometimes have been, with those of retinitis punctata albescens (chap, xii.),
which is an entirely different disease. The functions of the retina usually
suffer in a marked manner, so that a partial central scotoma may be
produced ; but some cases have been observed, in which vision was but
little, or not at all, affected.

This disease attacks both eyes, either simultaneously or with an
interval, and is most often seen in persons of advanced life, although it is
also found in middle age, and even in youth.

Treatment is of no avail.

Central Chorioiditis. — This is an exudation at the macula lutea,
without any similar disease elsewhere in the fundus. Absolute central
scotoma is its prominent symptom, and syphilis its usual cause.

Treatment. — Active mercurialisation ; and, where this can be adopted
early, the prognosis for recovery of sight is fairly good. Sub-conjunctival
salt injections aid the cure.

192 DISEASES OF THE EYE. [chap. vii.

Senile Central Chorioiditis occurs as a well-defined circular or
oval area of superficial atrophy of the chorioid at the macula, which
reveals the deeper vessels. It is met with in old people. It causes a
central scotoma. And although it is incurable, the patients are always
able to get about by themselves, owing to the retention of the peripheral
field of vision.

Syphilitic Chorioido-Eetinitis.— See Syphilitic Retinitis,
chap. xii.

Purulent Chorioiditis.— This consists at first in a purulent
extravasation between the chorioid and retina, and into the
vitreous humour, recognisable by the yellowish reflection obtained
from the interior of the eye on illuminating the pupil with
the ophthalmoscope mirror. The eyeball may become hard, the
pupil dilated, and the anterior chamber shallow. Purulent iritis
with hypopyon soon comes on, and the cornea may also become
infiltrated and slough away. There is usually considerable chemosis,
and the eyeball is pushed forwards by inflammatory oedema of the
orbital connective tissue. The eyelids are swollen and congested.
There is intense pulsating pain in the eye, and pains radiate
through the head ; and in this stage all the tissues of the eyeball
are engaged in the purulent inflammation, and the condition is
termed Panophthalmitis. It is the streptococcal infections ^vhich
end in this way, whereas those caused by the pneumococcus or
meningococcus usually fall short of panophthalmitis.

The pain in these cases is not severe ; and when the affection
occurs in children it may be mistaken for glioma of the retina
(chap, xii.) ; indeed, the name ' pseudo-glioma ' has, unfortunately,
been given to it. It must, however, be stated, that very recent
investigations go to show that pseudo-glioma has its origin in the
retina rather than in the chorioid. It is distinguished from glioma
by the muddy vitreous usually present wath it, by the posterior
synechise, and by the retraction of the periphery of the iris, with
bulging forwards of its pupillary part.

Causes. — This form of chorioiditis arises as an embolic or meta-
static chorioiditis, in connection both with epidemic and sporadic
cerebro-spinal meningitis (chap, xiv.) ; in some cases of metria,
similarly as purulent retinitis (chap, xii.) ; in pyaemia of the ordinary
type ; and in endocarditis.

In infancy and childhood, besides its occurrence with cerebro-

CHAP. VII.] THE UVEAL TRACT. 195

spinal meningitis, it has been known to be caused by, or associated
with, inherited syphilis, measles, bronchitis, diarrhoea, whooping-
cough, and omphalo-phlebitis ; and some infective blood-disease
is the fundamental cause of the process in every case, although it
is not always possible to determine its source.

Purulent chorioiditis may also be caused by direct infection,
as in perforating wounds of the eyeball, whether accidental or
operative ; foreign bodies piercing and lodging in the eyeball ; and
purulent keratitis. It may also come on suddenly in eyes which
are the subjects of incarceration of the iris in a corneal cicatrix,
through infection of the incarcerated iris. The bacillus subtilis and
pyocyaneus have been known to cause it.

Prognosis. — The ultimate result in the vast majority of cases
is loss of sight, with phthisis bulbi. The severe cases go on to
rupture of the eyeball through the cornea or sclerotic, after which
the pain subsides. It would seem from the description of authors
who have seen much of epidemic cerebro-spinal meningitis, that a
certain number of cases of irido-chorioiditis occurring in the course
of that disease do recover with retention of good sight.

The shrunken eyeballs produced by panophthalmitis are not
generally painful on pressure. They are not very liable to give
rise to sympathetic ophthalmitis, and the latter statement is also
true of the acute purulent process itself. It is cases of traumatic
plastic irido-chorioiditis which produce sympathetic ophthalmitis.

Treatment may be said to be powerless in this disease. The
utmost one can do is to endeavour to diminish the pain in the very
severe cases by warm fomentations, poultices containing conium,
hypodermic injections of morphia, or, finally, by eviscerating the
suppurating contents of the scleral cavity.

Excision of the eyeball, according to some surgeons, should not be
undertaken during purulent chorioiditis in the acute stage, through
fear that it might cause purulent meningitis, while others hold that
when meningitis follows enucleation, it is the result of a previous
metastasis and is not attributable to the operation, and therefore
they do not hesitate to enucleate if they consider it necessary.

Sympathetic Ophthalmitis, and Sympathetic Irritation.

Introductory. — By the term Sympathetic Ophthalmitis we
understand a general plastic uveitis (inflammation of iris, ciliary
13

104 DISEASES OF THE EYE. [chap. vit.

body, and chorioid) of one eye, caused by a plastic uveitis of the
other eye, the latter condition being most commonly due to a per-
forating trauma, or other perforation of the eyeball. Occasionally
sympathetic ophthalmitis takes the form of optic neuritis or
chorioiditis.

Purulent uveitis (panophthalmitis) of one eye does not cause
uveitis, either plastic or purulent, of the other eye.

There are no such diseases as sympathetic cataract, conjunc-
tivitis, detachment of the retina, keratitis, scleritis, etc.

The term ' sympathetic ' in this connection is an old one, and
probably would not be employed had the disease to be named at
the present time.

Sympathetic uveitis cannot be developed in the second eye, until
after uveitis has appeared in the first eye. A perforating injury of
the eyeball, or other perforation, which does not produce uveitis
in that eye, does not give rise to sympathetic ophthalmitis in the
fellow eye. Yet, traumatic uveitis in the injured eye does not cause
sympathetic ophthalmitis in every case.

The eye which has received the perforating injury is spoken of as
the exciting eye, and its fellow, which becomes the subject of . ym-
pathetic ophthalmitis, as the sympathising eye. The eyes are also
spoken of as the injured eye, and the sympathising eye ; also- as the
first eye, and the second eye.^

While sympathetic ophthalmitis is not a reflex condition, there
is an affection known as sympathetic irritation, which is a true
fifth-nerve reflex neurosis. These two affections, although some-
times closely associated clinically, are quite distinct from each
other.

Sympathetic Irritatiox. — This may be caused by almost any-
thing which produces irritability of the ciliary nerves in the first
eye — e.g. foreign bodies on the cornea or under the upper lid, losses
of substance of the corneal epithelium, anterior staphyloma, acute
glaucoma, iritis, dislocation of the crystalline lens, etc.

The most common symptoms of sympathetic irritation of the
second eye are : photophobia, lacrimation, vascular injection of the
front of the eyeball, and accommodative asthenopia, and, in a well-

1 French and German authors term the injured eye the sympathising
eye, and the second eye the sympathised eye.

CHAP. VII.] TBE UVEAL TRACT. 195

marked case, these symptoms become intensely distressing to the
patient. Neuralgia in the orbit and brow, and retinal asthenopia
sometimes occur.

Amongst the many causes of sympathetic irritation is an irritable
shrunken globe, whether the latter condition be the result of a
uveitis from a perforating injury, or of an idiopathic uveitis ; and
an irritable shrunken globe may give rise to sympathetic irritation
in the fellow eye at any time, even after many years. Having
remained quiet for so long, the shrunken eye begins to lacrimate,
and becomes painful and injected. A fresh injury to the stump may
be the cause of this, or it may be ossification of its chorioid, and
the irritation, whatever its cause, may be transmitted to the
sound eye.

But sympathetic ophthalmitis also is often caused by a shrunken
fellow eyeball, in which uveitis is present {vide infra) ; and of great
importance is the qxiestion : What relation, if any, has sympathetic
irritation to sympathetic ophthalmitis in such cases ? Is sym-
pathetic irritation to be regarded as a reliable and essential pre-
monitory symptom of sympathetic ophthalmitis ? The answer is
in the negative. Sympathetic irritation may last an indefinitely
long time, without being followed by sympathetic ophthalmitis.
Further, although some sign or signs of sympathetic irritation often
do precede the onset of sympathetic ophthalmitis, yet in many cases
every such sign is wanting. In view of the latter fact, it is, therefore,
wrong to postpone a prophylactic enucleation, until sympathetic
irritation shows itself.

Treatment. — When sympathetic irritation is caused by an irritable
shrunken globe on the opposite side, it can be immediately relieved
by removal of the stump. Rest in a dark room and sedative measures,
while they may seem to cure, merely lead to disappointment, owing
to the almost certain return of the symptoms, when the eye is
brought into use again. Moreover, as sympathetic irritation does
often precede sympathetic inflammation, it is wise to enucleate the
exciting stump in order to assure the safety of the second eye.

Sympathetic Ophthalmitis. Diagnosis. — The inflammation of
the uveal tract in the sympathising eye has no characteristics which
enable us to make the diagnosis ' Sympathetic Ophthalmitis,' for
precisely the same plastic or sero-plastic uveitis, as the case may be,

10(i DISEASES OF THE EYE. [chap. vii.

is seen under utlier conditions ; nor is the state of the first eye, taken
alone, a certain guide. To arrive at a diagnosis, it is necessary to
weigh the following data, and to take them c-ollcctively into con-
sideration : —

1. The condition of the exciting eye. and the nature of the
injury to. or disease of. that eye. .

2. The condition of the sympathising eye.

3. The interval that has elapsed between the injury to the
exciting eye, and the onset of the uveitis in the sympathising eye.

4. The state of the general system.

1. The Condition of the Exciting Eye. — As already stated, per-
forating injuries, or perforating corneal ulcers, of the first or exciting
eve, which are followed by plastic uveitis, are by far the most com-
mon causes of sympathetic ophthalmitis. The position of the wound
in the eye has no influence in the production of sympathetic oph-
thalmitis. Uveitis in the injured eye is due to infection of the
wound by micro-organisms derived from the foreign body, or instru-
ment, which has caused the wound, but sometimes perhaps from
the surface of the eye.

Either a purulent uveitis, or a plastic uveitis, may result from
the injury.

Purulent uveitis of a not very pronounced type (purulent in-
filtration of the vitreous humour, iritis, hypopyon) is very occasionally
followed by sympathetic ophthalmitis, but, and it is a remarkable
clinical fact, the marked purulent uveitis, which is called panoph-
thalmitis (p. 192), may be said never to give rise to it. It is obvi-
ouslv not a pyogenic micro-organism which causes sympathetic
ophthalmitis — for, if it were, the latter would be a purulent process —
but it may be some specific micro-organism.

If the infection of the injured eye be purulent, the inflammatory
reaction in it comes on within the first thirty-six hours after the
injury ; while the fibrinous or plastic inflammatory reaction, which
is so dangerous in relation to sympathetic ophthalmitis, and which
is caused by the specific organism, declares itself in the injured eye
less quickly and more insidiously.

In the case of the latter infection, the injection and irritation —
immediate results of the injury — disappear in a few days, but soon
return. The pupil then begins to dilate less well to atropine, the
tissue of the iris becomes less distinctly seen, some punctate deposits

CHAP. VII.] THE UVEAL TRACT. 197

appear on the posterior surface of the cornea, a few posterior
synechiix^ form, and opacities appear in the vitreous humour. At
first there is little or no pain, either spontaneously or on pressure,
and in this stage treatment may produce a marked improvement.
But sooner or later a relapse occurs, more synechise form, the iris
stroma becomes more indistinct and discoloured, often of a dull
greenish or yellowish grey, and the pupil becomes occluded. The
anterior chamber becomes shallower than normal, and the intra-
ocular pressure is diminished. Sight is much impeded by exudation
in the pupil and by opacities in the vitreous, and, in case of detach-
ment of the retina from shrinking of the inflammatory products
in the vitreous humour, it may be reduced in a marked degree.
There now is often pain on pressure of the eyeball, and the latter
soon begins to be diminished in size and becomes soft to the touch,
while the pressure of the tendons of the orbital muscles on this soft
eyeball gives rise to deep furrows on its surface. In short, the
injured eye has now become phthisical, and sight is quite lost. This
entire process may be completed in three or four weeks, or it may
occupy a considerably longer time.

The danger of sympathetic ophthalmitis supervening on a per-
forating injury of the first eye commences with the onset of plastic
uveitis in the injured eye — although the inflammatory process in
the second eye does not develop until after a certain interval {vide
infra) — and this danger is present, not only all through the acute
process in the injured eye, but also after this has subsided, and
when the eye has become shrunken, and even for many years more.

Shrunken eyeballs, as just stated, are liable to cause sympathetic
ophthalmitis. Pain on pressure of the ciliary region in them, show-
ing, as it does, the presence of inflammation of the ciliary body,
is an important danger-signal ; but the absence of pain on pressure
is not conclusive of the absence of cyclitis, for the latter may exist
to only a slight and yet dangerous degree, or the ciliary body may
be detached and out of reach of pressure.

The presence of a foreign body in the interior of the injured eye
does not necessarily lead to sympathetic ophthalmitis by the in-
flammatory reaction which it may cause ; for an aseptic foreign body
in the eye will cause an active inflammatory reaction ; yet this latter,
not being of bacterial origin, will not in its turn give rise to sym-
pathetic ophthalmitis. There are, however, few foreign bodies,

198 DISEASES OF THE EYE. [chap. vii.

except atoms of hot metal, which can be guaranteed as free from
infective material ; hence, as a rule, the presence of a foreign body
within the eye augments the danger of a perforating injury.

As in accidental perforating injuries, so also the wounds made in
the sclerotic or cornea in surgical operations, especially in cataract
extractions, may be followed by plastic uveitis, which will produce
sympathetic ophthalmitis. In consequence of the thorough aseptic
measures now in use, inflammatory processes after cataract extrac-
tions are very much less common than they used to be.

Perforations caused by ulcers of the cornea sometimes give rise
to uveitis, which may be followed by sympathetic ophthalmitis ; but
this is a rare event, although some iritis is present with almost every
severe corneal ulcer, and especially with those which tend to per-
forate. It is not easy to assign a reason for the rare occurrence of
sympathetic ophthalmitis in these cases.

In how far plastic uveitis of the first eye, which is not due
to perforating injuries or ulcers, is capable of being the cause of
sympathetic ophthalmitis is an important question.

Intra-ocular tumours, which have not yet perforated the sclerotic,
especially sarcoma of the chorioid, very occasionally set up a uveitis,
which leads to sympathetic ophthalmitis. In these cases necrosis
of the tumour has generally set in.

Ruptures of the eyeball from blows, which usually occur in the
ciliary region, without rupture of the conjunctiva — sub-conjunctival
ruptures of the sclerotic — sometimes come under our notice (p. 169).
These injuries almost invariably run a course free from inflammation
or even irritation of the injured eye, owing to the unbroken con-
junctiva, which covers the rupture, and prevents the access of
infecting bacteria ; and, consequently, they may be said not to
cause sympathetic ophthalmitis. It is probable that in the few
cases of this injury in which uveitis in the injured eye and sympathetic
ophthalmitis in the second eye appeared, some small opening in the
apparently sound conjunctiva existed.

Cases of gonorrhoeal ophthalmia have been published in which
sympathetic ophthalmitis came on. But these were all cases in
which ulceration, followed by perforation of the cornea, took place ;
and, hence, in which infection by bacteria other than the gonococcus
was quite possible.

2. The Condition oj the Sympathising Eye. — The diseased process

CHAP. VII.] THE UVEAL TRACT. 199

in the second or sympathising eye, as has already been stated, is,
with certain rare exceptions, an inflammation of the uvea, of a plastic
or fibrinous type, but never purulent, and almost always begins in
the uvea, or, at any rate, is commonly first discovered there as
iritis.

In the rare exceptions referred to, optic neuritis is the first sign
of sympathetic ophthalmitis, uveitis coming on subsequently ; and,
yet more rarely, optic neuritis has been seen as the one and only
sympathetic inflammation, the uvea remaining unaffected. It is,
however, held by some, that optic neuritis would be found to be the
first sign in the sympathising eye in nearly all cases if it were possible
to examine them before opacities in the vitreous humour, and
exudation in the pupil, interfere with an ophthalmoscopic diagnosis.

The appearance of the optic neuritis, or papillitis, as seen in
these cases, consists in hypersemia of the disc, without much swelling
of the latter, but with slight woolliness of its margin, the opacity
spreading a short distance into the surrounding retina. The veins
are distended, and the arteries are normal. The sight is considerably
affected, and there is often rather severe headache. The remedy
for sympathetic papillitis, occurring alone, is removal of the exciting
eye, and a few days after the operation the beneficial effect on the
optic nerve inflammation begins to show itself.

There are no reliable premonitory symptoms of the attack of
uveitis in the sympathising eye. As already stated, in many cases
sympathetic irritation does precede the first signs of sympathetic
uveitis, but it does not always do so ; and when sympathetic
irritation does appear, it need not always indicate the approach of
sympathetic uveitis.

The early signs of the actual presence of uveitis in the sym-
pathising eye are : — some fine punctate deposits on the posterior
surface of the cornea, and these are often the first symptom ; slight
pericorneal injection ; slight opacity of the aqueous humour ; some
discoloration and indistinctness of the iris ; contraction of the pupil,
but as yet no synechise ; some fine opacities in the vitreous humour ;
and slight loss of sight owing to these changes.

Posterior synechiae soon begin to form, and, in the most serious
cases, the adhesions occur, not merely between the margin of the
pupil and the anterior capsule of the lens, but, after a little while,
between the whole of the posterior surface of the iris and the capsule

200 DISEASES OF THE EYE. [chap. vii.

— total posterior synechia. The exudation which causes this exten-
sive adhesion soon pushes the iris forward — iris bombe— and renders
the anterior chamber shallow ; but after a time, when the fibrinous
exudation begins to shrink, the anterior chamber becomes deep at
its periphery, owing to retraction of the iris. The iris gradually
becomes more altered, its tissue more dull, discoloured, and in-
distinct, while large vessels form in it. Occasionally, in the anterior
chamber a small pseudo-hypopyon is seen, formed by the fibrin
which floats in the aqueous humour, some of which has gravitated.

The intra-ocular tension may become high, often very high,
owing to blocking of the angle of the anterior chamber with in-
flammatory products, and this glaucomatous tension is apt to be
attended by great pain. In consequence of the presence of such
extensive adhesions, eserine and pilocarpine have no influence on
this high tension, and the temptation to perform an iridectomy is
very great.

Yet it may be stated at once that no graver mistake can be
made in ophthalmic practice than to venture on any operative inter-
ference at this period. Far from doing good, an iridectomy is almost
certain to do harm. It is impossible, owing to the disorganised state
of the iris and its close adherence to the anterior capsule, to obtain
anything like a satisfactory coloboma ; and even if the tension be
reduced for a day or two after the operation, it soon becon>es as
high as before, in consequence of the rapid filling up of the coloboma
by proliferation of the inflammatory products, while the traumatism
of the operation only seems to lend additional violence to the
inflammation.

In the further progress of the disease, the cornea gradually
becomes more or less opaque, from derangement of its posterior
epithelium by the punctate deposits of fibrin upon it, and the crystal-
line lens becomes cataractous. After a time the high tension dis-
appears, and gradually, owing to shrinking of the vitreous humour.
low tension comes on. Vision, already very bad, sinks further. The
eyeball becomes smaller and very soft to the touch, and phthisis
bulbi, with complete blindness, is j^resented. This entire process
may occupy many months, and is often interrupted by short periods
of slight improvement in the symptoms, which raise the hope of
patient and surgeon.

In rai'e cases, the sympathetic uveitis comes on with violent

CHAP. VII.] THE UVEAL TRACT. _ 201

pain, chemosis, and swelling of the eyelids, and ends rapidly in
phthisis bulbi.

On the other hand, there is a less severe class of cases, in which
total posterior synechia does not form, the pupillary margin alone
becoming adherent, and these cases may run a comparatively favour-
able course.

A yet milder, and not uncommon, form of sympathetic uveitis
is that in which the only signs are : — punctate deposits on the
posterior surface of the cornea, and increased depth of the anterior
chamber, without any iritis. The punctate deposits are often at
first so fine as to be undiscoverable, unless by aid of a high convex
lens behind the sight -hole of the ophthalmoscope, or with a corneal
microscope. This form of sympathetic ophthalmitis is termed
serous sympathetic uveitis, and its prognosis is favourable. Its
one danger consists in the increased intra-ocular tension which is
liable to come on, but which should not tempt the surgeon to employ
an iridectomy, whereby a mild process might be converted into a
severe one.

More common than this typical serous uveitis are cases in which
some fibrin is thrown out, with resulting posterior synechia3 at the
pupillary margin, and where small round yellowish-white deposits
may be found with the ophthalmoscope in the chorioid — called
sympathetic disseminated chorioiditis — especially towards the peri-
phery of the fundus. In some cases the iris is free from inflam-
mation, the chorioid alone being affected in the manner mentioned.
This form of sympathetic ophthalmitis is not attended by much
irritation of the eye, nor need vision be much affected. The corneal
deposits very gradually increase in number, and consequently, vision
becomes affected to some extent, and then, if the tension do not
increase, the signs and symptoms after a time very slowly abate,
and a normal state is re-established. But relapses are liable to
occur even after some months, and they may assume the very
dangerous fibrinous type, vSo that, even in these mildest cases,
the utmost care in treatment and prognosis is needed.

3. The Interval that has elapsed between the Injury to the Exciting
Eye, and the Onset of Uveitis in the Sympathising Eye. — So far as
our present knowledge based on reliable cases enables an opinion
to be formed, the shortest interval which occurs between the injury
to the first eve, and the onset of uveitis in the second eve, is fourteen

202 DISEASES OF THE EYE. [chap. vii.

days, and very few cases with this shortest interval have been
reported. The period between the sixth and twelfth week after the
injury seems to be the most dangerous. In 170 of the 200 cases
collected by the Committee on Sympathetic Ophthalmitis of the
Ophthalmological Society the second eye was attacked within the
first year after the injury to the exciting eye. In only 12 of
the 200 cases was the interval more than one year, and the
longest interval was twenty years.

•i. The State of the General System. — As the subjects of traumatic
plastic uveitis in one eye are not immune against plastic uveitis in
the other eye due to syphilis, rheumatism, tubercle, diabetes, etc.,
it is necessary in each case to consider, whether the attack in the
second eye may not be a symptom of some systemic condition,
rather than a sympathetic uveitis.

From the above it appears, then, that the diagnosis of sym-
pathetic ophthalmitis depends on the following evidence : — (1) As
regards the exciting eye : Uveitis after perforation of the eyeball ;
except that in the rare cases in which sympathetic ophthalmitis is
caused by a chorioidal sarcoma, perforation is not necessary. (2) As
regards the sympathising eye : an inflammatory process of a plastic
type, which attacks all three portions of the uveal tract, is very
chronic in its course, often improves for a while, but relapses again.
(3) As regards the interval between the perforating injury in the
first eye, and the appearance of sympathetic ophthalmitis : an
interval of at least fourteen days is required. The period between
the sixth and twelfth week is the most dangerous, and very few
cases occur after the first year. (4) As regards the general system :
when careful examination of it does not reveal any condition, which
might be the cause of uveitis in the second eye, the probability of
this uveitis being sympathetic is increased.

Cases of Sympathetic Ophthalmitis have been recorded associated
with headache, with blanching of the cilia or eyebrows, and with deafness.
The loss of hearing was bilateral and was in most cases incurable.

Prognosis. — The prognosis of sympathetic uveitis is, in general,
serious ; yet it need not be quite hopeless, for even in severe cases
very occasionally, and of course more frequently in the less severe
cases, the sympathising eye does recover after prolonged treatment,
with a useful amount of vision. But in these rare cases which under-

CHAP. VII.] THE UVEAL TRACT. 203

go cure, the eyes are liable to occasional recurrences of the uveitis,
and at least a year should elapse since the last recurrence, before
a definite end to the diseased process can be said to have been reached.

The prognosis of sympathetic papillitis is quite favourable, when
once the exciting eye has been removed.

Treatment. — Measures calculated to prevent the onset of sym-
pathetic ophthalmitis are of the first importance. Where the
injury is so extensive as to make all prospect of saving sight in the
first eye hopeless, immediate excision of that globe is obviously
indicated. Where some prospect of saving sight in the injured eye
exists, attention is claimed in the first instance by the wound, which,
in those cases that come for surgical aid sufficiently early, is to be
protected from secondary infection by careful antiseptic cleansing,
abscission of any prolapsed portions of the uvea, suturing of the
wound in suitable cases, and dressing w4th bandage.

Should the wound be already infected, excision of the injured
eyeball is called for. No temporising is admissible — even some
useful vision being, for the time, retained by the injured eye is not a
contra-indication to the operation.

Where sight in the injured eye is lost, it will not be difficult for
the surgeon to recommend excision of the eyeball, and even to urge
it on the patient ; but when some useful sight is still retained, it s
not so easy to press this advice, although that should be done. We
know, indeed, that in some cases of traumatic uveitis sympathetic
uveitis does not supervene ; and, provided the first eye be not too
much disorganised by the injury, sight in it may ultimately be
obtained. But, unfortunately, we are unable to foretell whether
any given case will run so favourable a course ; and to temporise,
in the hope that it will do so, involves serious danger to the second
eye, and, it may be, ultimate loss of all sight in each eye.

In short, it cannot be doubted that there are cases in wdiich,
in the present state of our knowledge, we recommend removal of the
injured eye and where, had we decided to run a fearful risk by
allowing it to remain, not only would sight have been restored to it,
but no sympathetic ophthalmitis would have come on.

It must be further stated, that we cannot feel sure that our
removal of the first eye has averted sympathetic ophthalmitis from
the second eye, until four weeks after the operation has elapsed.

Nearly every ophthalmic surgeon has seen cases in which sym-

204 DISEASES OF THE EYE. [chat. vit.

pathetic ophthalmitis has appeared subsequently to excision of the
first eye, and in which, at the time of the operation, the second eye
was perfectly sound. There are well-authenticated cases where
sympathetic ophthalmitis appeared as long as four weeks after
enucleation of the injured eye. These cases are deplorable for the
patient, and very trying for the surgeon, especially if the outbreak
of sympathetic ophthalmitis should occur very soon after — perhaps
the day after — the operation. Yet, where sympathetic ophthalmitis
comes on after excision of the first eye, the operation need not be
regarded as having been quite useless ; for experience shows that the
attack of uveitis in the second eye is then usually of a comparatively
mild type, and fairly amenable to treatment.

In those cases in which the exciting eye has not yet been removed,
and in which sympathetic ophthalmitis in the second eye has com-
menced, what are our duties ? In the first instance, and at the earliest
possible moment, the exciting eye should be removed, always pro-
vided that it be quite and hopelessly blind. The immediate result on
the second eye of removal of the first eye under these conditions is
not marked, for the inflammatory process in the former seems to
proceed as actively as before. But statistics show that more svm-
pathising eyes are saved, or partially saved, when the injured eye
has been removed soon after the outbreak of sympathetic ophthal-
mitis, than when the injured eye is removed a considerable time
after the outbreak, or not at all.

But no exciting eye, which possesses even a slight degree of sight,
should be removed when once sympathetic ophthalmitis has appeared.
For it may well happen, that the sympathising eye becomes entirely
lost, while the exciting eye ultimately retains some degree of useful
sight. Great caution is therefore required in deciding whether the
exciting eye be capable of recovering to a certain extent, and this
frequently is a matter of considerable difficulty. Even a partially
phthisical eyeball may sometimes ultimately come round sufficiently
to gain useful vision. Schirmer lays down the following rule : — "When
sympathetic ophthalmitis has broken out, the exciting eye should not
be removed, unless it be absolutely blind ; or unless — if it still possess
merely perception of light — it has been for several weeks very soft,
and reduced in size ; or that, by reason of extensive corneal opacity,
all hope of restoration of form-vision must be abandoned.

If sympathetic ophthahnitis have b]-oken out. either before or

CHAP, vji.l THE UVEAL TRACT. 205

after removal of the exciting eye. the treatment and care of the
sympathising eye to promote its recovery must be considered.
This consists in the use of atropine, warm fomentations, and
sub-con junctival saline injections, which latter are held by some
to be very beneficial when high tension is present ; paracentesis
also does good in such an event. With these local means is com-
bined a general and prolonged course of mercurialisation — mercurial
inunctions or calomel internally, or both, care being taken to avoid
any severe stomatitis. We can speak very favourably of salicylate
of soda in gradually increasing doses until 140 or 150 grains are
taken daily. Salvarsan has given good results in the hands ot
some, while again it has proved disappointing. The patient is
to be confined in one warm but well-ventilated room, which should
be kept almost dark. As this treatment must often be continued
for many weeks or even months, it is trying for the patient ; but it
is to be remembered that the issue at stake is a fateful one.

No operation on the iris is to be performed so long as there is
the slightest inflammation, or tendency to inflammation ; and this
rule holds good, even if the tension of the eye become glaucomatous.
Premature operative interference has only the effect of lighting up
fresh inflammation ; and, even if the tension be reduced by an
iridectomy — which latter, owing to the diseased and degenerated
state of the iris and the inflammatory exudation behind it, cannot be
satisfactorily carried out — it w^ill soon again become high. In six
months or a year after every slight sign of inflammation, or tendency
to inflammation — of which injection of the ciliary vessels on inser-
tion of a spring speculum is not a bad criterion — has passed away,
and a longer interval can only be of advantage, it may be allowable
to perform an operation with the object of making an artificial pupil,
always provided that there is good prospect of materially improving
vision by this means. It must be remembered that, while every
operation has its risks, the risks are unusually great in such dis-
organised eyes ; and that any loss of sight is felt all the more in a
case in which the eye operated on is probably the only one possessing
even a little vision. On the other hand, when success crowns an
operation in these sad and perplexing cases, the gain is great.

If it be decided not to remove the exciting eye, after sympathetic
ophthalmitis has broken out, then the inflammatory process in it
is treated on lines quite similar to those above recommended for

206 DISEASES OF THE EYE. [chap. vn.

the sympatliisiiig eye, and the advice as regards operations is
the same.

Prophylactic Operations used for Sympathetic Ophthalmitis,

performed on the exciting eye.

Enucleation {or Excision). — Of prophylactic operations for sym-
pathetic ophthalmitis, enucleation of the first eye is the only one
which is regarded by all ophthalmic surgeons as thoroughly reliable,
when it is performed in time.

The speculum having been inserted, an incision is made in the
conjunctiva all round the cornea. The bulbar conjunctiva is separ-
ated from the globe freely in all directions with scissors. With a
strabismus hook each orbital muscle is caught up, and its tendon
divided close to the sclerotic. The eyeball is then made to start
forward by pressure of the speculum backwards, or the eye is seized
by the stump of the external rectus tendon and drawn forwards and
inwards. The optic nerve is then divided with strong scissors passed
into the orbit, either from the median or from the temporal side,
as far back in the orbit as possible. Sutures are not necessary.

Careful asepsis is of course necessary in enucleation of the globe.
Next to thorough sterilisation of the instruments, irrigation of the
cavity of the orbit as soon as the eyeball is removed, with a full
stream of sublimate solution, 1 in 5000, or of sterilised normal salt
solution, is the most important. Xeroform, or other fine antiseptic
powder, may be dusted into the orbit, and an aseptic dressing
should be applied with a pressure bandage. The orbit should be
similarly dressed every twenty-four hours.

Some cases of meningitis following upon the operation, and
which have proved fatal, are reported. There can be no reasonable
doubt but that, in some of these cases, septic matter made its way
along the lymphatics of the optic nerve to the meninges, and that this
septic matter was introduced upon the instruments, or escaped, in
purulent cases, from the interior of the eyeball. Hence the very
great importance of the careful aseptic precautions above indicated.

An artificial eye can usually be inserted after a fortnight, but
should not be constantly worn for a month at least, because it is
liable to cause irritation and conjunctivitis until that time has
elapsed.

Artificial Eyes {Prothesis Oculi). — These should be worn after enuclea-
tion, not merely for the cosmetic effect, but also because they prevent

CHAP. VII.] THE UVEAL TRACT. 207

the occurrence of entropion and are better for the socket. Thoy are
sometimes used over a phthisical eyeball, and in such cases they look
very well and have a greater range of movement than after an enucleation.
Glass eyes are made in two forms, the simple shell and the " reform "
eye, which is hollow inside. The latter is more comfortable, as its edges
are more rounded, besides having the advantage of filling the orbital
cavity better. A slight concavity at the upper margin, which comes to
lie opposite the supra-orbital notch, will serve to distinguish a right from
a left eye. Artificial eyes should be removed for the night and carefully
washed. Patients soon learn to insert and remove the " eye " with the
greatest ease. The method of insertion is as follows : The upper lid
having been raised with the left hand, the upper edge of the eye, which
is held in the right hand, is inserted under the upper lid, the lower lid is
then drawn down with the left hand which is removed from above, and
the eye slips into place ; it may be removed by insinuating a bent hair-pin,
or head of a pin, under the lower edge. After having been worn for a year
or so, the surface of the glass gets rough, when it should be re-enamelled,
otherwise it may give rise to irritation and cause shrinking of the socket.
Owing to the presence of a slight discharge, the socket should be bathed
daily with a mild astringent lotion.

The reform eyes have one drawback, namely that in rare cases they
break spontaneously. We have seen two instances in which this occurred :
the patient hears a sudden snap, and when the eye is removed a small
hole is seen on the posterior surface and the chip corresponding to it is
found in the interior of the eye. The eye in reality collapses owing to
the diminished air pressure in?ide it. Reform eyes can be made with a
bulge above in order to diminish the unsightly hollow which sometimes
exists above the upper lid after enucleation.

Evisceration. — For mode of performing this operation vide p. 147.
Evisceration is not held to be so good a safeguard against sympathetic
ophthalmitis as excision, and is not employed for that purpose, unless
quite soon after the injury. The advantage of evisceration over enuclea-
tion lies in the better stump provided by it for a prothesis, and the
consequent better cosmetic effect.

Mules' Operation. — For the description of this operation see p. 148.
The objections to and advantages of this operation are the same as in
evisceration, but it gives a better stump than the latter.

Therapeutic Operations used in Sympathetic Ophthalmitis.—

The field for these operations, if it exist at al], is exceedingly limited.
Practically the only indication for operative interference, in the active
period of sympathetic ophthalmitis, is long-continued high tension ;
and in the foregoing pages the warning has been repeatedly uttered,
that any operative meddling with the iris in this period is more
apt to aggravate the process than to alleviate it ; and that, even if
tension be relieved by an iridectomy, it soon becomes high again,
owing to fresh plastic exudation.

208 DISEASES OF THE EYE. [chap. vii.

Should it seem imperatively necessary to endeavour to reduce
a long-continued high tension, sclerotomy is to be preferred to
iridectomy. It may have a beneficial effect, and is not likely to do
harm. It can be repeated more than once, should it be deemed
necessary.

Paracentesis of the cornea is a measure which can be used as
a temporary means of relief for high tension, and it, too, may be
repeated.

Optical Operations used in Sympathetic Ophthalmitis. — The object
of these operations is to provide an artificial pupil in the sympathising
eye after all inflammation, or tendency to it, has ceased, in order to improve,
or to restore, vision which is interfered with by closure of the pupil. Similar
operations may be indicated occasionally in the exciting eye, in cases
where it has not been excised.

The cardinal point to be borne in mind, it may again be stated, is,
that these operations must never be performed until six months at least
have elapsed — and a longer period is preferable — after all and every
tendency to inflammation, or irritation, has subsided. Inattention to
this rule will result in a re-lighting of the inflammation, re-closure of the
pupil which may have been made, or intra-ocular haemorrhage, and a
long period of waiting before any further operation can be undertaken ;
or else the globes may become shrunken, and all hope may be at an end.

Moreover, as, even under the most favourable conditions, and with
the most skilful operation, inflammation may return, or intra-ocular
haemorrhage may occur, or the eye may become phthisical, no operation
should be done unless the advantage to be gained from it, if successful,
promises to be considerable.

The three chief operations, one or other of which may be applicable,
are : — Iridectomy or Iridotomy, extraction of the clear or cataractous
lens — for the lens is often cataractous from interference with its nutrition
by reason of the irido-cyclitis — or, discission of the cataractous lens.

Iridectomy. — It is only exceptionally that iridectomy can be of use,
in those eyes which have been the subjects of the severer plastic uveitis,
resulting in total posterior synechia. In these cases, the tissue of the
iris has undergone such extreme degeneration, that it is impossible to
obtain more than mere shreds of the membrane with the forceps, so that
a satisfactory coloboma can rarely be made, besides which there is often
a dense mass of fibro-plastic tissue (cyclitic membrane) behind, and
adherent to, the iris, irritation of which lights up an inflammatory reaction,
which often closes the coloboma.

Iridectomy is indicated in those cases rather, where a less severe form
of iritis has existed, resulting in a complete ring synechia of the pupillary
margin only. Here a wide coloboma may often be made satisfactorily.
The iris should be seized with the forceps at about the lesser circle. If
seized at the pupillary margin, the intimate adhesion between the latter
and the lens capsule may cause injury to the capsule, and consequent

CHAP. VII.] THE WEAL TRACT. 209

traumatic cataract. Iridotomy by De Wecker's or Ziegler's methods, or
with a punch (chap, x.), is often of very great service in the more severe,
cases.

Extraction of the Lens. — This is indicated, if, on the formation of a
coloboma, the lens be found to be cataractous, in those cases of ring
synechia where iridectomy has been performed and the coloboma has
closed again ; and in practically all cases of total posterior synechia, be
the lens clear or opaque. In the former class of cases the ordinary com-
bined method of cataract extraction answers the purpose, or a preliminary
iridectomy may be made some weeks previously.

Cases of total posterior synechia require a procedure, such as one or
other of the following : —

WenzeVs Method. — The puncture, counter puncture, and incision are
the same as in an ordinary cataract extraction, but the knife on entering
is passed through cornea, iris, lens, iris, cornea. The lens is thus delivered
as completely as possible, and out of the membrane composed of degener-
ated iris, retro-iridic connective tissue, and capsule, a V-shaped piece is
cut with the forceps-scissors. The traumatism of this operation is great,
and not every globe will bear it, and phthisis bulbi may follow.

Hirschherg' s Method. — An incision is made with a keratome in the
lower margin of the cornea. With a fine capsule forceps, introduced
into the pupil, the thickened anterior capsule is seized and drawn away
and, by inserting a spatula, as much of the lens as possible is extracted.
Some weeks later the pupillary membrane, composed of lenticular remains,
posterior capsule, and inflammatory products, is divided with a cystotome.
The advantage of this operation is that the iris is not interfered with.

Discission. — This operation was employed by the late Mr. George
Critchett with success, in some cases where cataract was the main obstruc-
tion to sight. A discission needle is passed, by a boring motion, through
the lenticular capsule ; another needle is then passed in close to the first,
and by separating one point from the other a rent is made. This is followed
generally by the escape into the anterior chamber of a small quantity of
cheesy lens matter, which becoines gradually absorbed, and in the course
of some weeks the capsule closes again. The operation has to be repeated
several times before a clear pupil is obtained, care being taken that all
irritation from the previous operation has subsided before another be
undertaken. The chief danger in this operation is irritation and high
tension, from swelling of the lenticular masses in the disorganised eye.

Pathology. — In spite of the vast amount of experimental and clinical
work which has been done in this direction, the pathology of sympathetic
ophthalmitis is still wrapt in mystery. It would be impossible in this
book to discuss even briefly the various theories which have been advanced
to explain the causation of this disease and the method whereby it is
transferred to the sound eye. We must only content ourselves with a
general statement indicative of the lines on w^hich research is proceeding
at the present time.

The microscopical appearances in eyes affected with sympathetic
ophthalmitis were first described by Fuchs, who also contrasted this type
of inflammation with that caused by the usual infective micro-organisms.

210 DISEASES OF THE EYE. [chap. vii.

The latter, to which he gave the name of Septic Endophthahiiitis, is charac-
terised by the presence of a fibrino-plastic exudation, confined chiefly
to the surfaces of the iris and ciUary region, which exudation, except in
acute purulent cases, becomes converted, later on, into a dense fibrous
tissue, enveloping the lens and adherent to the iris and ciliary body (cyclitic
membrane).

Sympathetic ophthalmitis, on the otlier hand, consists in an infiltration
of the very substance of the whole uveal tract, including the chorioid.
In the early stages the uveal tract becomes infiltrated with lymphocytes
and plasma cells, while, later on, localised collections of endothelioid
cells appear sometimes associated with the presence of giant cells, the
whole process being rather suggestive of tubercle. This cellular infiltration
may cause great thickening of the whole uveal tract, and may even pene-
trate the sclera. It must be said however that a septic endophthalmitis,
in varying degrees of severity, usually accompanies the sympathetic type
of inflammation, and further a typical proliferating uveitis has now and
then been observed in cases of so-called idiopathic uveitis without perfora-
tion of the eye, and this fact, as well as the clinical symptoms and progress
of such cases, suggests the idea that they are of the same nature as true
sympathetic ophthalmitis.

Pathogenesis. — The oldest theory, which attributed the origin of this
disease to a reflex neurosis, may be dismissed. The most generally received
opinion is that sympathetic ophthalmitis is a parasitic affection, although
the organism supposed to be accountable for it still remains to be discovered.
Assuming that it is a parasitic affection, how is the disease transferred to
the sound eye ? By some the view is still maintained that the micro-
organisms make their way directly from one eye to the other along the
optic nerves (migratory ophthalmitis of Deutschmann), but it is much more
likely that the transmission takes place indirectly through the blood, the
organisms or their toxins gaining admission into the circulation. It has
also been suggested (Meller) that the infection is endogenous and that the
micro-organisms are already present in the blood at the time of the injury
to the first eye.

The latest attempt at an explanation is that of Elschnig, who seeks
to prove experimentally that sympathetic ophthalmitis is an anaphylactic
phenomenon. The course of events he takes to be as follows : — The
breaking down of the cells of the inflamed uveal tissue in the injured eye
sets free an albuminous antigen the absorption of which sensitises not only
the whole organism but also gives rise to a local sensitisation of the uveal
tissue in the second eye ; any irritation of this eye will then Hglit up an
anaphylactic reaction in the form of a uveitis.

This is no doubt a very attractive hypothesis, but it is open to several
objections, of which we need only mention a few. In the first place, it
has not been proved that auto-anaphylaxis does occur in human beings, or
that a local anaphylaxis can be induced in one eye by an autogenous antigen
developed in the other. Besides, admitting even that the second eye can
be sensitised in this way, some kind of disturbing element is required to
set the anaphylactic reaction going in it. Elschnig thinks that gastro-
intestinal auto-intoxication supplies this element, and that this is proved

CHAP. VII.] THE UVEAL TRACT. 21

by the presence of iudicanuria, in patients suffering from uveitis. But
this is a view which requires very much stronger proofs than those which
have been advanced in its favour (see p. 186).

Interesting observations have also been made on the condition of the
blood of patients suffering from sympathetic uveitis. It has been found
that there is an increased lymphocytosis, the number of the large mono-
nuclear cells in particular being augmented, and on account of the resem-
blance of the blood picture to that which obtains in syphilis it has even been
suggested tliat syni]mthoti(' ophthalmitis may be caused by a protozoon.

Injuries of the Uveal Tract.

Injuries of the Iris. — Punctured Wounds of the cornea, or of the
corneo-scleral margin, frequently implicate the iris, but rarely do so
without also injuring the crystalline lens or ciliary body, on which
then the chief interest centres, as being the organs from which serious
reaction is most likely to emanate. A small simple incised wound of
the iris is not of great importance, for inflammatory reaction is not
common, and any extravasation of blood at the seat of the iris wound,
or into 'the anterior chamber (hyphaema) becomes absorbed, while,
in most cases, the functions of the iris will probably not be affected,
nor sight endangered. Nevertheless, as iritis does sometimes occur,
it is desirable to use measures calculated to prevent it, such as
atropine, a dressing, and rest of the eye and general system. Even
extensive wounds of the iris are not often, as such, associated with
serious danger to the eye, although the loss of continuity in the iris
never closes up. Where, for instance, the iris is cut in its entire
width from ciliary margin to pupillary margin, the permanent result
is a wide coloboma, the margins of which may be adherent to the
corneal wound. When the iris is prolapsed in the corneal wound,
it is only possible to reduce it, if the case be seen within a few hours
of the occurrence of the accident. If this cannot be effected, it is
necessary to abscise the prolapsed portion. Incarceration of the
iris in the corneal cicatrix may lead to secondary glaucoma, cystoid
cicatrix, secondary septic infection of the iris, etc.

Foreign Bodies of small size, such as bits of steel or iron, may
perforate the cornea and fasten in the iris, the puncture in the
cornea closing rapidly, and possibly no aqueous humour being lost.
It is necessary always to remove such a foreign body without delay,
although for some time it may cause no reaction. An iridectomy

212 DISEASES OF THE EYE. [cHAr. vii.

should be done, the foreign body being removed along with the
portion of iris in which it is embedded.

Bloivs on the Eye are apt to cause, in addition to hemorrhage
into the anterior chamber from the iris or from the canal of Schlemm,
one of several remarkable lesions of the iris, namely : —

1. IridodiaJijsis'^ — i.e. separation of the iris from its attach-
ment to the ciliary body. This is usually accompanied by consider-
able hyplnema. As much as one-half of the circumference of the
iris may be involved in the lesion ; or, the latter may be so small as

to be diagnosed only by the pre-

sence of the resulting small fresh

haemorrhage near the ciliary margin
of the iris ; or, after this has be-
come absorbed, by aid of light
transmitted to the eye by the
ophthalmoscope, when not alone
the physiological pupil, but also
Fig. 71. the minute marginal traumatic

pupil Avill be illuminated. It is
rarely that there is more than one dialysis. In certain degrees of the
detachment, by reason of the sphincter of the iris having lost its
fixed point, it becomes stretched in a straight line (Fig. 71) art the
part corresponding with the dialysis, and assumes a D shape ; or, if
the detachment be more extensive, the pupil becomes kidney-shaped ;
or the detached portion may entirely cover the pupil. The detached
portion, too, may be turned on itself (anteflexion of the iris), the
uveal surface being to the front. The functions of the eye after
such an injury, even when extensive, are sometimes but little dis-
turbed, or there may be monocular diplopia.

It is stated that an iridodialysis does not become re-attached ; but
we have seen a very minute iridodialysis heal, and another such case
is recorded. The lengthened use of atropine promotes such a result,
but it can only be hoped for if the iridodialysis be not extensive, and
if the case be seen early.

Iridodialysis does not increase in extent in the course of time,
or lead to further mischief in the eye.

An operation for the remedy of iridodialysis has been proposed and

i'ptj, 5td\i'(T£s, a separating.

CHAP. VII.] THE UVEAL TRACT. 213

successfully performed by Chalmers Jameson as follows : — If the dialysis
be of some extent, two needles each carrying a suture of fine silk-worm
gut are used. The first needle is passed through the corneo-scleral
margin 2 mm. from tlie limbus, into tlie anterior chamber, under and
through tlie torn iris-margin, of which less than I mm. is taken up, and
through the cornea. The needle is liberated from the suture. The second
needle is similarly introduced at a convenient distance from the first,
according to the dimension of the dialysis. An incision is then made in
the corneo-scleral margin in a straight line between the points of entrance
of the sutures, leaving a short bridge of scleral tissue between those points,
and the ends of the incision. An iris hook is passed into the anterior
chamber between the iris and cornea, and the sutures are in turn carefully
snared, the corneal ends drawn out of the cornea into the anterior chamber,
and out through the corneo-scleral incision, thus enabling the sutures to
be tied on the bridges of scleral tissue at each end of the incision without
including the cornea. The sutures when tied bring the torn surface of
the iris in contact with the inside of the linear incision, but not between
its lips, and re-attachment of the iris by agglutination of the corneo-scleral
wound is thus accomplished. Where the dialysis is of moderate dimension,
one suture only is needed ; but where two are required, they should both
be introduced into the iris before either is tied.

2. Retroflexion of the Iris. — From a blow on the eye, the whole, or more
commonly a portion, of the iris in its entire width can be folded back on
the ciliary processes, giving the appearance of a very dilated pupil, or
of a coloboma produced by a wide and peripheral iridectomy. In a true
coloboma the ciliary processes would be easily seen, but not so in retro-
flexion, for the processes, being covered by the retroflexed iris, present a
smooth surface. A slight dislocation of the lens in the direction away
from the iris lesion is often observed. Retroflexion of the iris cannot be
cured, but useful vision is retained, if the injury be uncomplicated.

3. Rupture of the Sphincter Iridis. — There may be but one rupture, or
there may be a number of small ruptures distributed round the pupil.
They show themselves as small triangular gaps in the pupillary margin,
their bases directed towards the latter. This condition is also incurable,
and some permanent disturbance of vision due to the mydriasis results.

4. Dehiscence of the Iris between the pupillary and ciliary margins.
This is a slit-like rupture of the iris, which runs in a radial direction through
the whole width of the iris, with the exception of the sphincter. The diag-
nosis sometimes cannot be made with certainty until, after a few days,
the blood-clot covering the dehiscence is absorbed. The opening may be
caused to close by the use of a miotic, which, by contracting the sphincter,
brings the edges of the dehiscence together.

5. Traumatic Aniridia. — The whole iris is torn from its ciliary insertion,
and may be found lying in the anterior chamber or under the conjunctiva,
having in the latter case passed through a rent at the corneo-scleral
margin. Not only does the anterior chamber contain blood, but the
vitreous humour is often infiltrated with haemorrhage. When the extra-
vasated blood has become sufficiently absorbed, the absence of the iris will
be noted, and in many instances the ciliary processes will be visible. If

214 DISEASES OF THE EYE. [chap. vii.

these latter are visible, the diagnosis ' aniridia ' can be definitely made, but
cases do occur in which, notwithstanding the absence of the iris, the ciliary
processes are not visible, owing probably to changes in them which cause
them to shrink. Such cases then are difficult to distinguish from retro-
flexion of the iris, but tlie importance of the diagnosis is not great.

6. Traumatic Mydriasis, and Miosis. — Of these, mydriasis is
the more common. The dilatation is of medium degree, and the
pupil is usually of irregular shape^oval, pear-shaped, or more
dilated at one part than elsewhere — and contracts but slightly, or
not at all, to light. Paralysis of accommodation usually accom-
panies traumatic paralysis of the sphincter iridis. The mydriasis
is probably the result of concussion of the delicate nerve-endings in
the sphincter of the iris. (See above, under Rupture of the Sphincter
Iridis.) Traumatic mydriasis may recover after a long interval,
but in most instances it remains as a permanent defect, with
some derangement of vision due to it and to the paralysis of
accommodation.

With traumatic miosis there is apt to be spasm of accommoda-
tion, which may produce apparent myopia. The prognosis is
fairly good.

TreaUnent. — For mydriasis, protection spectacles, galvanism,
and eserine. For miosis, atropine.

Injuries of the Ciliary Body. — Punctured Wounds, and Foreign
Bodies perforating the sclerotic at a distance of about 5 mm. around
the cornea, are almost certain to implicate the ciliary body. If
there be no prolapse of the ciliary body, nor any foreign body in the
interior of the eye, the sclerotic wound may heal by aid of a bandage
without further ill results. If a prolapse of the ciliary body or iris
be present, it is to be abscised, with careful aseptic measures ;
and if the sclerotic wound be large, it may be thought desirable to
unite its margins with sutures.

Wounds of the ciliary body are apt to cause cyclitis, especially
if the former be incarcerated in the sclerotic wound in healing, for
the incarcerated portion is liable to become infected.

* Injuries of the Chorioid. Small Foreign Bodies may pierce the
sclerotic, or the cornea and lens, and may lodge in the chorioid, and,
if favourably situated, can then be detected with the ophthalmo-
scope, and always by the Rontgen rays if of metal (chap. x.). These
foreign bodies require operative removal by the magnet, if of steel

CHAP. VII.] THE UVEAL TRACT. 215

or iron (chap, x.) ; or, if the foreign body cannot be extracted,
the eyeball must be removed, to avert sympathetic ophthalmitis.

Incised Wounds of the sclerotic very frequently involve the
chorioid (p. 170).

Rupture of the Chorioid near the posterior pole of the eye is
often produced by blows on the eye, and is seen with the ophthal-
moscope as a whitish-yellow (the colour of the sclerotic) crescent
some two or three papilla-diameters in length, and about one papilla-
diameter distant from the optic entrance, the concavity of the
crescent being directed towards the latter. Immediately after
the accident, extravasated blood sometimes prevents a view of
the rupture. Some chorioiditis may result ; but, w^hen this passes
away, good vision is frequently restored and maintained, provided
detachment of the retina does not ultimately supervene from cica-
tricial contraction at the seat of the rupture. On the other hand, a
scotoma in the field may be produced, and if the rupture be in the
region of the macula lutea, serious loss of sight may be caused.

Treatment. — Careful protection of the eye, and abstinence
from use of it, with dry cupping at the temple for three weeks,
or until it may be assumed that all inflammatory tendency has
subsided.

Blows upon the eye may cause Extravasation of Blood in the
Chorioid. If small, these extravasations do not extend beyond the
chorioid. But, in the case of copious extravasation, the haemorrhage
is poured out from the chorioidal vessels between that coat and the
sclerotic, lifting and bulging forward the chorioid ; or between the
chorioid and retina, giving rise to a detachment of the latter ; and
if the retina give way the blood is poured out into the vitreous
humour. Should there be no vitreous humour opacity, the extra-
vasations in the chorioid can be seen with the ophthalmoscope as
somewhat indistinct (owing to resulting opacity in the overlying
retina) small red spots, or large round red spots, darker in the centre
than at the margin. That these haemorrhages are in the chorioid
can be recognised from the fact that they lie behind the retinal
vessels. The haemorrhages become slowly absorbed, and after a
time, provided that they have not ruptured the retina, useful vision
may be restored.

Treatment. — Complete rest in bed. Atropine. Bandage.

21G DISEASES OF THE EYE. [chap. vii.

New Growths of the Uveal Tract.

New Growths of the Iris. — Cysts of the Iris. Also known as Cysts
of the Anterior Chamber. — These vary from a very small size to that which
would fill the anterior chamber. They may have either serous or solid
contents. The serous form is occasionally congenital, but in the majority
of cases the cyst originates in epithelial cells from the cornea, epidermis,
etc., which are implanted in the iris on the occasion of a penetrating wound.
The cysts with solid contents (epidermoid elements) usually have their
origin in an eyelash which has entered the anterior chamber by occasion
of a perforating corneal wound. All these cysts are sources of serious
danger to the eye (irido-chorioiditis, glaucoma, etc.), and, it has been
stated, may even be the cause of sympathetic ophthalmitis, and hence
their removal is called for. This can be effected without much difficulty
if the tumour be small, but if it have attained a large size, and become
adherent to the posterior surface of the cornea, the attempt is often un-
successful. A long incision should be made in the corneo-scleral margin,
and the cyst, along with the portion of iris to which it is attached, drawn
out and cut off.

Solitary Tubercle. — Solitary tubercle may be accompanied by a few
smaller growths, but it generally begins as a single yellowish-white tumour,
often without iritis, which gradually increases in size until it may fill the
anterior chamber. It finally involves the cornea, which it perforates,
forming a f ungating mass, and this subsequently breaks down, leaving
only a small shrunken globe in the socket.

Treatment. — Tuberculin in the early stages ; and, if perforation should
take place, excision of the eyeball.

Sarcoma. — The iris is that portion of the uveal tract which is most
rarely affected with primary sarcoma. It arises usually from a congenital
pigmented na3vus of the iris, and is commonly a melano-sarcoma ; but
leuco-sarcoma has also been recorded. As the tumour increases in size,
it fills the anterior chamber, and grows backwards into the ciliary body
and into the canal of Schlemm. It is not usual for the tumour to become
extra-ocular by growing through at the corneo-scleral margin, as does
tubercle of the iris. Irritation or inflammatory symptoms are not often
present ; and secondary glaucoma does not come on until a late stage,
when the growth has filled the anterior chamber, or involved the ciliary
body extensively. But care must be exercised in making a diagnosis ;
we have had under observation for a great many years two cases of small
pigmented tumours in the angle of the anterior chamber which have
shown no signs of growth. Unless the tumour increases in size no treat-
ment is necessary.

Treatment. — Enucleation of the eye should be advised as soon as the
diagnosis of sarcoma of the iris has been made. When the sarcoma is
small, there is naturally a desire on the part of the surgeon to save the eye,
which probably has full vision, by excising the portion of iris in which
the growth is seated, and there are some cases on record in which this was
done, and where no recurrence of the tumour took place. But in adopting

CHAP. VII.] THE UVEAL TRACT. 217

this conservative method there is serious danger ; for it is not possible
to determine clinically whether the sarcomatous growth is truly, or only
apparently, confined to the limited region of the iris, where it can be seen.
Even in the early stages of many cases of sarcoma of the iris, the neoplasm
invades the ligamentum pectinatum, the canal of Schlemm (Plate IV.
J'ig. 5), or the ciliary body ; so that, although the iris tumour be thorouglily
removed, the growth reappears in the eye before long, while in the mean-
time risk of infection of the general system has been run.

Carcinoma. — A few cases of metastatic carcinoma of the iris and ciliary
body are on record, with the breast as the primary seat of disease.

Ophthalmia Nodosa. — See p. 80.

New Growths of the Ciliary Body. — Sarcoma of the ciliary body is
generally pigmented, and often passes unobserved, until it attains con-
siderable size as a brown mass, which was at first concealed from view
by the iris. Occasionally it is first noticed when it makes its appearance
at the angle of the anterior chamber. It usually also grows backwards
into the chorioid, and runs the same course as sarcoma of the chorioid,
but in rare cases extends round the whole ciliary region (ring sarcoma)
(Plate IV. Fig. 5). Renioval of the eyeball should be urged, but is often
for a time declined by the patient, as sight is but slightly affected in the
early stages.

Myosarcoma originating in the ciliary muscle has been observed a few
times.

Carcinoma. — Secondary carcinoma may occur in the ciliary body as
in the iris and the chorioid, but is very rare.

New Growths of the Qhonovdi,— Sarcoma is by far the most
common neoplasm of the chorioid, and the chorioid is the most
common seat of ocular sarcoma. It is seen at all times of life, but
most frequently between the ages of forty and sixty. Both melano-
sarcoma and leuco-sarcoma occur, and may originate in any part
of the chorioid.

If seen in a very early stage, it is easily recognised from its
projecting over the general surface of the fundus, the retina lying
closely applied to it ; but, unless it be in the region of the macula
lutea, when it leads to a central scotoma, it may not cause any
serious disturbance of vision, and hence may not at that period
be brought under the notice of the surgeon. The diagnosis from
detachment of the chorioid at this stage is made by the presence in
the latter condition of the characteristic chorioidal vessels, and by
the peculiar colour of the chorioid. Detachment of the chorioid,
too, is much rarer than sarcoma.

The retina is at first closely applied to the surface of the growth,
but soon the retina becomes detached (Fig. 72) by reason of serous

218

DISEASES OF THE EYE.

[chap. VII.

Fig. 72. — Chorioidal sarcoma
springing from posterior pole of
fmidus. Complete detachment of
retina. Lens pushed forwards.
Iris pressed against posterior sur-
face of cornea. As yet no cupping
of the disc.

exudation from the chorioid ; and this may be accompanied by
opacity in the vitreous humour, which contributes in rendering

the diagnosis w^ith the ophthal-
moscope difficult or impossible.
If the detachment be shallow^ and
the retina translucent, the tumour
may still sometimes be seen
through the sub-retinal fluid by
aid of strong illumination ; and
even direct sunlight may be em-
ployed in some such cases. Often
the detachment commences at a
part of the fundus not imme-
diately over the tumour, but some
distance removed from it. Owing
to the great, and often sudden,
defect of vision which comes on
in this stage, we very commonly
see these cases now for the first
time. The history of the case may aid us ; w-hile the absence
of the more usual causes of detachment of the retina should make
us suspicious of an intra-ocular tumour, and the fundus should
be carefully examined, with dilated pupil, in all such cases.

At this and at later stages, Leber's, or other. Sclerotic Trans-
illuminator (Fig. 73, J size) is a valuable diagnostic aid. It consists
of a small electric lamp (6), w^hich re-
quires a current of eight to ten volts,
enclosed in a metal jacket {a). The
anterior end of the lamp is in contact
with a short glass rod (c) covered
with a hard rubber sheath. The light
of the lamp is transmitted along the
glass rod, and the exposed end (d) of
the latter is placed on the sclerotic of
the cocainised eye, in a dark room.
Then, if the eye be normal, or even if
a ripe cataract be present, the pupil lights up with the familiar
red glow from the chorioid. But if, internal to the spot at which
the glass rod is applied, a new growth be present, the pupil does not

Fig.

CHAP. VII.] THE UVEAL TRACT. 219

light up — it remains dark. By slipping the rod over the whole of
the suspected region, or as much of it as can be reached, or, indeed,
over the whole exposed sclerotic, it can be ascertained whether an
intra-ocular growth be present. The only limitation to the method
is in those cases where the tumour is situated much behind the
equator, a region in which the rod cannot be brought in contact with
the sclerotic. The brightness of the red reflex in the pupil depends
very much on the incidence of the rays passing through the sclerotic,
and the brightest reflex is obtained in the normal eye when the glass
rod is placed at about the equator of the eyeball. The observer
should look at the pupil from the direction of the patient's gaze,
whether this be straight forward or to one side. Non-pigmented
tumours do not interfere with illumination of the pupil ; nor do
opacities in the cornea, or lens, nor even a ripe senile cataract.
Inflammatory opacities in the vitreous humour do not interfere
with the pupil-glow, but an intra-ocular haemorrhage even of slight
amount does so. Diaphanoscopy may also be of use in the
diagnosis ; it consists in covering the patient's face with a rubber
mask, leaving only two holes for his eyes, and transilluminating the
eye with an electric lamp placed in the mouth.

Soon the intra-ocular tension increases. This makes the diagnosis
again more easy in many cases, for the combination of detached
retina and increased tension exists only with intra-ocular tumours.
The increased tension may come on very slowly, and without ciliary
neuralgia ; or more rapidly, and with all the signs and symptoms
of acute glaucoma. Yet, if the case come under observation now^
for the first time, the diagnosis may be by no means easy, should
the refracting media be opaque (as always in acute glaucoma), and
consequently the detachment of the retina concealed from view.
Here, again, the history of the case is all we have to depend on,
especially the fact of the patient having noticed a defect at one side
of his field of vision previous to the onset of glaucoma.

In the next stage of the growth it perforates the cornea or sclerotic,
and, increasing rapidly in size, although still covered with conjunc-
tiva, it pushes the eyeball to one side, the upper lid being stretched
tightly over the whole. On raising the lid the tumour is seen as a
bluish-grey mass with irregular surface. The conjunctiva is now
soon perforated, and the surface of the tumour becomes ulcerated,
with a foul-smelling discharge and occasional haemorrhages. The

220 DISEASES OF THE EYE. [chap. vii.

tumour gradually invades the surrounding skin and the bones
of the orbit, and by extending through the sphenoidal fissure and
optic foramen reaches the l)ase of the brain.

Another, and less common, course of chorioidal sarcoma, is that
in which, without first perforating the cornea or sclerotic, the tumour
sets up irido-cyclitis, leading to phthisis l)ulbi. Cases in which
sarcoma of the chorioid was found in shrunken eyeballs have given
rise to the view that such eyeballs are prone to develop sarcoma.
While it is possible that sarcoma may develop in a shrunken eyeball,
it is tolerably certain that, in the majority of the cases in which both
diseases are present, the sarcoma has been the primary disease,
and has undergone regressive metamorphosis. An apparent cure is
thus produced, but in cases in which the opportunity of sufficiently
prolonged observation has been afforded, the growth has again
become progressive. (See also glioma of the retina, chap, xii.)

It is in cases such as these that sarcoma of the chorioid occasion-
ally gives rise to sympathetic ophthalmitis.

It is usually upon the neighbouring tissues of the eyeball
becoming involved that secondary growths begin to form in other
organs, the one most prone to be affected being the liver. The
lungs, stomach, peritoneum, spleen, and kidneys may all be attacked.

Chorioidal sarcoma is almost always primary, but it has been
seen a few times as a metastatic disease.

Carcinoma. — This is extremely rare, and the cases of it on record,
as in the iris and ciHary body, were all of metastatic origin, the primary
disease being in the breast. It is not possible to distinguish chorioidal
sarcoma from chorioidal carcinoma by the ophthalmoscope. Other,
but rare forms of tumour of the chorioid, are : — Sarcoma carcinomatosum,
Osteo sarcoma, and Lymphoma.

Tubercle appears in cases of acute miliary tuberculosis as round,
slightly prominent, pale yellowish spots, of sizes varying from 0*5
to 2*5 mm. in diameter, situated always in the neighbourhood
of the optic papilla and macula lutea, and unaccompanied by
pigmentary or other chorioidal changes. There may be but one
of these foci, or there may be many of them. When they occur,
it is, as a rule, in a late stage of the general disease, but they have
occasionally been noted long before its appearance. According to
Stephenson they are found in 50 percent, of the cases of tubercular
meningitis, while Marple (who used the electric ophthalmoscope)

CHAP. viT.] THE UVEAL TRACT. 221

believes that the percentage is much higher. In obscure cases of
the general disease, the ophthalmoscope can therefore render
valuable diagnostic aid by revealing these minute growths in the
chorioid.

Very rarely does a tubercular tumour grow in the chorioid in
cases of general chronic tuberculosis, attaining to a large size, and
destroying the eye similarly as does sarcoma or carcinoma.

In young children it may be impossible to diagnose between a
tubercular tumour of the chorioid and a glioma of the retina (chap,
xii.). Yet, as in either case enucleation is indicated, the diagnosis
is not of great clinical importance.

Treatment. — So long as, in cases of sarcoma and carcinoma, the
tumour is wholly intra-ocular, enucleation of the eyeball should be
performed, and may be done with fair hopes of saving the patient's
life, if the disease be primary, but it should be stated that even
when the eye is removed in the early stage metastasis may never-
theless take place. When the orbital tissues have become involved,
extirpation of all the contents of the orbit, and even, if necessary,
removal of portions of its bony walls, ought to be undertaken, should
the general health permit, in order to rid the patient of his loath-
some disease ; although the probable presence of secondary growths
elsewhere renders but slight the prospect of saving the patient's life.

Cases of miliary chorioidal tubercle do not call for direct
treatment.

In cases of tubercular tumour, the question of removal of the
eyeball must depend upon the general state of the patient ; but,
if it seem probable that life will be prolonged until after the ocular
growth would have become extra-ocular, removal of the eye should
be recommended.

* Other Diseases of the Chorioid. — Posterior Staphyloma. — This
condition will be described in connection with myopia (chap, xvi.),
which is its almost constant cause.

Detachment of the Chorioid. — As the result of copious loss of vitreous,
during operations, or from injury, detachment of the chorioid is not un-
common, but it does not require to be specially diagnosed in these instances,
and therefore it is not important to consider it further here.

Idiopathic detachment of the chorioid is extremely rare. Its ophthal-
moscopic appearances are apt to be taken at first sight for a simple detach-
ment of the retina, or for leuco-sarcoma ; but, on closer inspection, the

222 DISEASES OF THE EYE. [chap. vii.

chorioidal stroma is observed to lie immediately behind the detached retina,
and its vessels, etc., are seen in the upright image by aid of the same lens
as are the retinal vessels. The chorioid is not everywhere detached, but
is separated from the sclerotic in several different places, and these
detachments are seen in the form of apparently solid hemispherical pro-
tuberances rising abruptly from the fundus into the vitreous humour. In
otlier places tlie chorioid is in contact with the sclerotic, although in
some of these positions there may be detachment of the retina alone.
The vitreous humour is more or less opaque. Vision is greatly lowered or
quite destroyed.

It is probable that a clironic chorioido-rctinitis has been an antecedent
condition in all of these cases. Indeed, signs of old retinitis are often
present, such as perivasculitis and connective tissue striation ; and in one
case retinitis was actually observed long before the detachment of the
chorioid came on. Adhesions between the chorioid and sclerotic are
formed in consequence of this inflammation ; and then inflammatory
exudation takes place behind the chorioid, and separates it from the
sclerotic, where it is not adherent to the latter.

The process ends either in phthisis bulbi, in consequence of vascular
changes and disturbances of nutrition, or in cure to a certain degree, in so
far as by absorption of some of the exudation, and by alteration of the
remainder of it into connective tissue, a return of the chorioid and retina
to their normal position is rendered possible ; but even then restoration of
sight, with tissues so disorganised, cannot be looked for.

Treatment hitherto seems to have been of no avail. Probably active
mercurialisation might afford the best chance of doing good, should a case
come under notice.

Fuchs has pointed out that detachment of the chorioid occurs in a good
many cases of cataract extraction some days after the operation, although
there has been no loss of vitreous, and also in some cases of iridectomy.
It can often be found with the ophthalmoscope, and even sometimes with
the oblique illumination, in those cases of cataract extraction in which the
anterior chamber has not formed, or in which, having formed, it has become
empty again. It is mainly after iridectomy for chronic simple glaucoma
that chorioidal detachment lias been noticed. It has also been observed
after trephine operations. The probable explanation is, that a slight
aperture of communication has been niade between the anterior chamber
and the sub-chorioidal space, through which the aqueous humour passes
behind the chorioid. With the re-establishment of the anterior chamber,
the chorioidal detachment goes back, and the prognosis is in all cases good
as regards vision.

Central Senile Areolar Atrophy of the Chorioid. — This is not a very rare
disease and presents the appearance of a white patch, often of considerabl?
extent, at and around the macular region. In some cases a haemorrhage
in the chorioid and posterior layers of the retina forms the starting-point
of the disease. The retinal functions always suffer much ; for an absolute
central scotoma is produced, which renders reading and writing impossible,
although orientation is not greatly impeded, as the periphery of the field
remains intact.

CRAP. viT.] THE UVEAL TRACT. 223

Tlie discovery of the presence of this disease, after a eataract has
been successfully removed, is sometimes a source of intense disappoint-
ment both to patient and surgeon, which cannot be guarded against,
unless the condition of the fundus oculi have been noted while the cataract
was still incipient.

Treatment is of no avail, but absolute rest of the eyes from all attempts
at near work, and the use of dark protection spectacles are important, so
that, at tlie least, the advance of the disease may not be promoted.

■Malformations of the Uveal Tract.

Malformations of the Iris. — Corectopia {Kop-n, the pupil ; eKTowo?, out of
position), or malposition of the pupil. The pupil sometimes occupies a
position farther from the centre of the iris than normally.

Polycoria {iro\v^, many ; Kopii, the pupil). — Where there is more than
one pupil. The supernumerary pupil may be separated by only a small
bridge from the normal pupil, or it maybe situated very near the periphery
of the iris. In neither case has it a special sphincter.

Persistent Pupillarij Membrane. — This appears, most commonly,
in the form of very fine threads stretched across the pupil. They
cannot be mistaken for posterior synechi?e, as they spring from
the anterior surface of the iris at the corona, some distance, that
is, from the margin of the pupil. They do not interfere with the
motions of the pupil, nor with vision.

Coloboma {Ko\of36s, maimed) and Irideremia ( pt?, the iris ; Ip-qixla,
want of). — Coloboma, partial defect, and Irideremia (or Aniridia), complete
absence of the iris, have been shown by Treacher Collins to be due to a
similar cause — in short, that they are different degrees of one and the
same condition. They are sometimes hereditary.

Before the iris is formed in the foetus there exists — between the posterior
surface of the cornea and the anterior capsule of the lens — the anterior
portion of the fibro-vascular sheath. This receives its blood-supply
partly from the ciliary arteries, and partly from the vessels in the posterior
fibro-vascular sheath, which are prolonged round the sides of the lens to
join it. The cornea, anterior fibro-vascular sheath, and lens lie in close
contact with each other.

The iris is developed by growing forwards from the margin of the
anterior chamber, and in so doing has to insinuate itself between the
cornea and anterior fibro-vascular sheath on the one hand, and the lens
on the other, pushing the prolongation from the posterior fibro-vascular
sheath in front of it. The anterior fibro-vascular sheath subsequently
becomes the pupillary membrane, of which portions sometimes persist
(see above).

If we suppose some abnormal adhesion to occur between the cornea,
anterior fibro-vascular sheath, and lens-capsule, or some delay in their
separation at the whole circvimference of the future anterior chamber, we

224 DISEASES OF THE EYE. [chap. vii.

can understand how a mechanical obstruction to any growth of the iris
forwards would be introduced, resulting in complete absence of the iris,
or irideremia. Irideremia maybe complete or partial. In the latter case
it may be the inner circle only which is wanting, giving the pupil the
appearance of dilatation with atropine. Where the entire iris is absent
the ciliary processes can be seen all round. The condition may be binocular.
If the obstruction be confined to a portion only of the anterior chamber,
the corresponding portion only of the iris will be prevented from growing
forwards, and the result will be one or more congenital colobomata.

The patients suffer chiefly from dazzling by light, from which oitlior
protection or stenopaeic spectacles afford some relief.

Malformations of the Chorloid. — Coloboma. — This is a solution of
continuity occurring always in the lower part of the chorioid, and usually
associated with a similar defect in the iris. It may commence at the ojDtic
papilla, and involve the ciliary body also, and sometimes the sclerotic
(chap, vi.), and even the cr.ystalline lens may have a corresponding notch ;
or it may not extend so far in either direction. The condition is recognised
ophthalmoscopically by the white patch, due to exposure of the sclerotic
where the chorioid is deficient. Sometimes the retina is absent over the
defect in the chorioid. a circvimstance v.hich may be ascertained by the
arrangement of the retinal vessels ; but, even if it be present, its functions
at that place are wanting, and a defect in the field of vision exists. Central
vision is often normal.

Abnormalities in the Colour of the Iris. — The greenish discoloration of
the iris due to iritis and hyphsema, has been already alluded to ; a similar
discoloration is seen in some cases of chronic iridocyclitis due to the yellow
colour of the aqvieous humour, but other changes in colour, congenital or
acquired, also occur.

Heterochromia is the term applied to the condition in which the iris of
each eye is of a different colour, or in w'hich patches of a different colour
appear in the iris in one eye. This is usually a congenital anomaly. Where
the tw^o eyes are not of the same colour it has been noticed in many cases
that the eye with the lighter tint, especially if blue, is prone to become
affected with cyclitis, and to develop secondary cataract.

Ectropion of the Uveal Pigment, in which the brown pigment passes
round the margin of the pupil on to the anterior surface of the iris, is met
with as a congenital defect, and also in some cases of glaucoma and irido-
cyclitis with increased intra ocular tension.

Siderosis is a peculiar greenish-yellow or rusty discoloration of the
iris caused by the infiltration of the tissues of the eye with soluble iron
salts resulting from the oxidation of chips of iron or steel which found their
way into the eye as the result of an accident, and had lodged in it for a
considerable time.

Albinismus, or defective pigmentation of the chorioid and iris.
This is usually accompanied by defective pigmentation of the hair
of the body. The iris has a pink appearance, due to reflection of
light from its blood-vessels, and from those of the choroid, and

CHAP. VII.] THE UVEAL TRACT. 225

with the ophthalmoscope the hitter vessels can be seen down to
their finest branchings. The pupil to the observer is red, not black.
The light which enters the eye, not being partially absorbed by
pigment, causes the patient much dazzling, and high degrees of the
condition are usually accompanied by nystagmus. In childhood the
albinismus and attendant symptoms are more marked than later in
life, when some degree of pigmentation usually takes place.

Much advantage may be derived in many of these cases by the
use of stenopaeic spectacles, at least for near work. Any defect of
refraction should be carefully corrected, in order to give the patients
the best possible use of their eyes.

Operations on the Iris.

Iridectomy. — This is performed for optical purposes, in zonular
cataract, corneal opacities, or closed pupil ; to reduce abnormally
high intra-ocular tension, in primary and secondary glaucoma ; and
for the removal of tumours or foreign bodies in the iris.

The instruments required are a spring speculum ; a fixation
forceps, with spring catch (Fig. 78) ; a lance-shaped iridectomy
knife (keratome) (Fig. 74), or a Graefe's cataract knife ; a bent iris
forceps (Fig. 75), or a Tyrrell's hook (Fig. 76) ; a pair of iris scissors
curved on the flat (Fig. 77), or de Wecker's forceps-scissors ; and a
small spatula.

The width of the coloho^na depends a good deal on the length of
the corneal incision, for it cannot be wider than the incision is long.
Its depth depends on the proximity of this incision to the corneo-
scleral margin. If a wide and very peripheral coloboma be desired,
the incision must be long, and must lie actually in the corneo-scleral
margin ; the iris forceps being then introduced, a portion of the iris
corresponding with the length of the incision may be seized, drawn
out, and cut off, the blades of the scissors being applied parallel
and close to the incision, and by this means a coloboma, as at Fig.
79, is produced. An incision somewhat inside the corneal margin
will give a pupil, as in Fig. 80. A narrow coloboma (Fig. 81) is
obtained by making a short corneal incision, which may be more or
less peripheral as circumstances require ; by taking up as little as
possible of the iris in the forceps, or by using a Tyrrell's hook, instead
of an iris forceps, for catching and drawing out the iris ; and by
15

226

DISEASES OF THE EYE.

[chap. VII,

Fig. 74.

Fig. 75.

Fig. 76.

Fig. 77.

applying the blades of the scissors at right angles to the incision in
the corneal margin.

In glaucoma a wide and very peripheral coloboma is required.
For optical purposes a narrow iridectomy is required, because with
a wide coloboma the diffusion of light may be very troublesome to
the patient.

CHAP. VII.]

THE UVEAL TRACT.

227

The best position for an iridectomy for glaucoma is in the upper
quadrant of the iris, as when made there the subsequent dazzling
by light and the disfigurement are least. But the position, by

Fig. 78.

preference, for an optical pupil is below and to the inside, being that
most nearly in the direction of the axis of vision. If, however, this
position be occupied by a corneal opacity, the coloboma should be
made directly downwards ; or, if that place be ineligible, then
downwards and outwards, or directly outwards, or directly in-
wards. The upward positions are of little use for optical pupils,
owing to the overhanging of the upper lid ; yet it often happens
that we have no other choice.

In the Performance of an Iridectomy, the eye should be fixed
with a forceps at a position on the same meridian as that in which
the coloboma is to lie, but at the opposite side of the cornea, and
close to the latter.

The point of the lance-shaped knife is then entered almost per-
pendicularly to the surface of the cornea, and made to penetrate
the latter. As soon as the point of the blade has entered the anterior
chamber, the handle of the knife is lowered, and the blade is passed

Fig. 79.

Fig. 80.

Fig. 81.

on into the anterior chamber in a plane parallel to the surface of the
iris, until the incision has attained the required length. The handle
of the knife is now lowered still more, so as to bring the point of the
blade almost in contact with the posterior surface of the cornea, in
order to prevent any injury to the lens in the next motion. The
knife is then very slowly withdrawn from the anterior chamber.

228 DISEASES OF THE EYE. [chap. vii.

At the same time the aqueous humour Hows oli' slowly, and the
crystalline lens and iris come forwards.

The fixation forceps is now taken over by the assistant, and the
closed iris forceps is passed into the anterior chamber, its points
directed towards the posterior surface of the cornea, so as to avoid
engaging them in the iris. When the pupillary margin has been
reached, the forceps is opened as widely as the corneal incision will
permit, and the corresponding portion of the iris is seized and drawn
out to its full extent through the corneal incision.

With the scissors held in the other hand the exposed bit of iris
is snipped off quite close to the corneal incision. Care should now
be taken that the angles of the coloboma do not remain in the wound ;
and, if they are seen to do so, they must be reposed by pushing them
into their places gently with the spatula.

Iridotomy. — For description and uses of this operation see
chap. X.

CHAPTER VIII.

THE PUPIL.

The movements of the iris, which produce contraction and dilatation
of the pupil, are involuntary and are governed by two un striped
muscles — namely, the sphincter pupillse, and the dilator pupillae.
The sphincter is a ring of muscle situated close to the margin of the
pupil and is supplied by the third nerve, while the dilator is a thin
muscular layer, of which the fibres are arranged radially, and which
is situated near the posterior surface of the iris, and is supplied by
the sympathetic nerve.

These muscles are set in motion either by reflex stimuli, or by
what Parsons aptly terms synkinesis — i.e., by association with
other voluntary or involuntary movements.

Contraction of the Pupil is brought about by the light reflex, or by
the accommodation synkinesis.

The Light Reflex depends upon the transmission of the stimulus
from the retina, by the afferent path (the optic nerve and tracts) to
the pupil constricting centre of the third nerve nucleus, in the floor
of the Aqueduct of Sylvius, and thence by the efferent third nerve
path to the sphincter pupillse. As regards the afferent path, it has
been ascertained that the optic nerve contains fibres of two different
calibres, coarse and fine, of which one set, it is not known with cer-
tainty which, are visual fibres and the other afferent pupillo-con-
strictor fibres. The pupillary fibres undergo partial decussation
in the optic commissure, and pass into the optic tracts. They leave
the tract before it reaches the external geniculate body, but at what
point, and their further route to the third nerve nucleus, are not
certainly known. It is on the whole probable that the path taken
is by the superior brachium to the superior quadrigeminal body, and
thence by new connections to the third nerve nucleus of the same
and of the opposite side. The portion of the third nerve nucleus
which gives origin to the pupillo-constrlctor fibres is the Edinger-

229

230 DISEASES OF THE EYE. [chap. viii.

Westphal nucleus, situated in the median part of the main nucleus.
The efferent pupillo-constrictor path is contained in the trunk of the
third nerve. In the orbit the pupillo-constricting fibres pass into the
branch which supplies the inferior oblique, and leave it again by the
short root of the ciliary ganglion. From this ganglion the sphincter
nerve filaments — the short ciliary nerves — pass to the eyeball, pierce
the sclerotic around the optic nerve, and pass on the inner surface of
the sclerotic to the iris. The innervation of the ciliary muscle (the
muscle of accommodation) is from the same source.

The Accommodation Synkinesis is contraction of the pupil associ-
ated with accommodation, or more strictly with convergence of the
optic axes. The act of accommodation of the eye for near vision is
intimately bound up with the act of convergence of the optic axis,
which takes place simultaneously with accommodation (see p. 6),
and it can be shown, that if, experimentally, accommodation and
convergence be dissociated, it is possible to accommodate without
producing contraction of the pupil, but not to converge the optic
axes without that synkinesis. Hence it is really with the act of
convergence, not with the act of accommodation, that contraction
of the pupil is associated. The object of this contraction is to cut
off rays which would fall on the peripheral portions of the lens,
portions which are not curved in the change for accommodation
in the same degree as is the centre of the lens.

Engorgement of the bloodvessels of the iris, as in hypersemia, or
inflammation, or following paracentesis of the anterior chamber, is
a third influence which causes contraction of the pupil.

Dilatation of the Pupil. — The nerve supply of the dilator pupillae
is from the cervical sympathetic. The path originates near the third
nerve nucleus, and passes through the medulla to a region, in the
upper dorsal and lower cervical portion of the lateral column of the
spinal cord, called the cilio-spinal centre. The path leaves the cord
by the central roots of the first three thoracic nerves, and thence, by
way of the rami communicantes, passes on to the first thoracic
ganglion. Thence into the anterior and posterior limbs of the annu-
lus of Vieussens and by the cervical sympathetic to the superior
sympathetic ganglion, from whence the path enters the skull by
the cervico-gasserian fibres to reach the gasserian ganglion. From
this ganglion it passes to the ophthalmic division of the fifth nerve
by its nasal branch, and then, leaving it, it joins the long ciliary

CHAP. VIII.] THE PUPIL. 231

nerves which enter the eye around the optic nerve, and reach the
iris by passing forwards between sclerotic and chorioid. It seems
probable, however, that all the dilating fibres do not run to the eye
by way of the cervical sympathetic, and that the gasserian ganglion
receives pupil-dilating fibres from the sympathetic traversing the
cavum tympani. Dilatation of the pupil is brought about by the
sensory reflex, or by the cerebral synkinesis.

The Sensory Reflex can be induced by almost any sensory stimulus
— e.g., the prick of a pin or a pinch on the neck, galvanism applied
to the leg, the tickling of a sensitive place in the region of the fifth
nerve on the face, etc. Westphal observed dilatation on shouting
loudly into the ear of a person under chloroform. Schiff and Foa
found that in curarised dogs and cats a dilatation took place on the
application of every stimulus, not necessarily painful, applied to the
nerves of common sensation in any part of the body. Indeed, it is
not necessary in the human subject that the stimulation should pro-
duce any sensation, for stimulation of the skin of the affected side in
hemianaesthesia, as also in sleep and in coma, will find response in
dilatation of the pupil. The afferent impulses, in the case of nerves
of common sensation, reach the cilio-spinal centre by way of the
posterior spinal columns.

The Cerebral Synkinesis is induced by psychical emotions. The
pupils of a cat in anger dilate, and those of a frightened child. In
sleep, or when under the complete influence of an ansesthetic, the
pupils are contracted, for then all psychical and sensitive stimuli
are reduced to a minimum. Facts authorise the conclusion that
the medium dilatation of the pupil in the healthy state depends
chiefly on the intensity of these stimuli, habitually transmitted
through the sympathetic. If in any individual they be slight, his
pupil is contracted ; if intense, it is dilated. In delicate, nervous,
excitable people the pupils are often much, and habitually, dilated.

In addition to those already mentioned, there are causes for the
dilatation of the pupil, which can hardly be referred to simple reflex
action, but which seem to be, like the contraction of the pupil on
convergence of the visual lines, synkinetic with other centres in the
medulla oblongata, especially with those for respiration and uterine
action. With every deef inspiration or expiration a considerable
pupillary dilatation takes place, not identical with that slight dilata-
tion occurring on each ordinary inspiration, and depending on varia-

232 DISEASES OF THE EYE. [chap. viii.

tion of blood pressure, but due to simultaneous stimulation of the
respiratory and pupil-dilating centres by retention of carbonic
acid gas in the blood. Marked dilatation at the beginning of each
labour pain has been observed, and may be explained as an associated
action of the neighbouring centres for uterine movements and pupil-
dilatation.

Hippus. — In addition to the normal pupillary motions described in
the foregoing, and visible for the most part to the naked eye of the observer,
there is a phenomenon of pupillary motion, termed hippus, which is
discoverable only by aid of a corneal microscope or loup, consisting in
perpetual, but very minute and irregular, fluctuations in size of the pupil.
It is due to the ever-varying sensitive and psycliical reflexes which are
thus constantly manifesting their influences on the pupil.

The Reflex Mobility of the Pupil to Light is tested most commonly
for the purpose of deciding the existence of a lesion in the iris itself
(posterior synechise) or in the efferent path (third nerve). The
next most common object of the test, is to determine the sensi-
tiveness to light of the retina or of the visual centre. It affords
generally a sufficient test of the presence or absence of quantitative
perception of light : but the latter function may be wanting in
certain diseased states, and yet the pupil-reflex take place, but
this is a rare condition ; or the pupil-reflex may be wanting,- and
still perception of light be present. AVhen light enters into the
eye the pupil of that eye contracts : this is the Direct Reflex Contrac-
tion, but owing to the connection between the two third nerve nuclei
the pupil of the unilluminated eye contracts at the same time, and
this constitutes the Indirect or Consensual Contraction. The test is
best performed in diffuse daylight, with the patient's face directed
towards the window, a distant object being looked at, and the eye
which is not under examination being carefully excluded from the
lioht. The surgeon then, having observed the size of the pupil to
be examined, excludes the eye from light with his hand for some
moments. On removing the excluding hand, a normally reacting
pupil will be found to have become dilated ; and this dilatation,
after an interval of about half a second, will be observed to give
way to an extreme contraction, which is maintained only for a
moment, and is then succeeded by a moderate dilatation, and the
pupil then again contracts somewhat, and so on, until, after some
further minute oscillations, it comes to a standstill. The explana-

CHAP. VIII.] THE PUPIL. 233

tion for this liippus is that each contraction of the pupil, by diminish-
ing the supply of light to the retina, contains in itself the cause of
the succeeding dilatation ; and, for the converse reason, each dilata-
tion sets a-going the succeeding contraction, until at last equilibrium
is attained. A comparison between the maximum of dilatation and
maximum of contraction, along with the promptness and rapidity
with which the contraction takes place, enables the observer to
form an estimate of the activity of the pupil-reflex. In performing
this test it is important that the patient's gaze should be fixed all
the time on a distant object — hence, unless where a mere trace of
perception of light remains, the test used with the artificial light
is not so reliable as that with daylight — so that the accommodation
synkinesis may not vitiate the experiment. The consensual reflex
of the pupil, as well as the direct, should always be tested — one eye
being alternately excluded and exposed, the motions of the pupil of
the other eye are observed and compared with those of its fellow.
In a case of atrophy of one optic nerve, say the left, on illuminating
the left eye no movement of the pupil would take place in either
eye, but on throwing light into the right eye both pupils would con-
tract, the right directly and the left consensually. In examining
the pupils we have also to decide whether they are of equal size ;
and, in order to avoid error through posterior synechise, the com-
parison should be made, with both eyes open, successively in two
very different degrees of illumination. Under normal conditions
equality in size of the pupils will exist, with both eyes open, and
there will be only a slight difference if one eye be shaded ; for the
normal consensual pupil-reflex is not quite so active as the direct
reflex. If the pupils be found of different sizes, the least movable
one is usually the pathological pupil ; but this question is often
difficult to decide. Finally, it should be noted whether the direct
pupil-reflex is similar in all respects in each eye. For the Argyll
Robertson pupil see chap, xiv., part iii., and for Wernicke's hemi-
opic pupillary reflex see chap, xiv.. Hemianopsia.

Action of the Mydriatics on the Pupil.— Solution of sulphate
of atropine dropped into the conjunctival sac dilates the pupil,
through absorption into the aqueous humour. For it has been
shown that the aqueous humour of an eye into which atropine
has been instilled acts as a mydriatic when dropped into another
eye. It is evident that atropine acts, not merely by para-

234 DISEASES OF THE EYE. [chap. viii.

lysing the sphincter pupillse, but also by stimulating the dilator,
inasmuch as in complete paralysis of the third nerve instillation of
atropine produces a further dilatation of the pupil. If cocaine be
combined with atropine in the solution, or if it be dropped in as a
separate collyrium, a further dilatation of the pupil takes place.
Whether this is to be referred to contraction of the blood-vessels
of the iris, or to stimulation of the sympathetic supplying the dilator
pupillcT, is not clear. Scopolamine, homatropine, ephedrine, etc.,
act similarly to atropine.

Action of the Miotics on the Pupil.— These drugs— of which
the chief are Eserine and Pilocarpine — act in all respects as the
complete antagonists of the mydriatics, by stimulating the endings
of the third nerve in the sphincter pupillse. Morphia, taken inter-
nally or used hypodermically, has an antagonistic effect to atropine,
when it is absorbed into the system, and is employed as an
antidote in cases of atropine poisoning.

CHAPTER IX

GLAUCOMA.i

As the primary cause of Glaucoma remains, to a great extent,
obscure, it cannot well be included under the heading of the diseases
of some definite part or tissue of the eye, and therefore it becomes
necessary to assign to it a special chapter.

The chief and essential symptom of this disease is Increased
Intra-ocular Tension — increased hardness of the eyeball — due to
over-fullness of the globe. All the other symptoms of the disease
result from this one.

There is Primary Glaucoma and Secondary Glaucoma.

In primary glaucoma, the increased tension comes on without
any previous recognisable disease of the eye ; and it is with it we
have mainly to do in this chapter.

In secondary glaucoma, the increased tension is caused by
obvious antecedent disease in the eye.

Primary Glaucoma.

Primary glaucoma is almost invariably a binocular disease. Yet
it does not always attack each eye simultaneously, indeed it is more
common for the disease to appear in the eyes with an interval of
months, or longer.

Of primary glaucoma there are, clinically, two kinds — Chronic
Simple Glaucoma, and Congestive Glaucoma which may also be
acute or chronic. But these different clinical varieties of glaucoma
are liable to run into each other — chronic simple glaucoma may

1 From yXauKos, sea-green. The name was given to the disease by the
old writers, on account of the greenish reflection obtained from the pupil
in some cases. But this greenish reflection is seen in other diseased con-
ditions, and is not characteristic of glaucoma.

235

236

DISEASES OF THE EYE.

[chap. IX.

become congestive, and congestive glaucoma may after a time take
on the chronic simple form.

Increased intra-ocular tension, as stated, is the chief and essen-
tial symptom of glaucoma, whatever form of it may come before
us ; although this increased tension may not always be present in
the same degree, nor at every hour of the twenty-four.

If the tips of the index fingers be placed close together on a
normal eyeball (Fig. 82), and gentle pressure be made with them
alternately, the eyeball will be felt to pit slightly, and a sensation
of fluctuation is given to the fingers. The amount of this pitting,
or fluctuation, varies according to the de-
■^^■■^H|^H gree to which the eyeball is hlled with its
^^^BV^I^B^^H humours, and also, to some extent, accord-
^^B^" -J ]^H ^^^» ^^ *^® thickness of the sclerotic coat.

is harder than the normal globe, because it

Fig.

is too full.

But normal eyes may have a tension
below or above the average ; and, in eyes of
the latter class, it is occasionally difficult to
decide whether or not the tension be abnor-
mally high. If it be a question of one eye only, then a comparison
of its tension with that of its fellow decides the question, for the
physiological tension is always the same in each eye.

For the purposes of clinical notation certain signs have been
adopted. Normal tension is indicated by the lettter T, or Tn, slight
increase of tension by T + 1, still higher tension by T + 2, while
T + 3 denotes stony hardness of the eyeball. In the same way
diminished tension is T — 1, T — 2, and T — 3. T + ? and T — ?
indicate that it is doubtful whether the tension be slightly above
or below the normal.

Schiotz's tonometer is a most valuable instrument for estimating tension ;
for delicacy and accuracy it is much superior to the digital method, which
is subject to more sources of error. The instrument (Fig. 83) consists
of: (a) A perforated cylinder A ending in a footplate D, curved to adapt
itself to the surface of the cornea. This cylinder supports (by means of
the arms HH) a pointer P which moves on the scale SS. (6) Sliding
freely in the cylinder is a rod or stylet B, to which one (W) of several weights
can be affixed above and which acts on the pointer, (c) A collar C, wliich
runs on whool bearings on the cylinder A, is provided witli two L-sliaped

CHAP. IX.]

GLAUCOMA.

237

projections (F) for the pui'pose of holding the instrument in the vertical
position.

The cornea having been anaesthetised, the patient is placed in the
recumbent position with the chin slightly raised, so that the instrument
may be placed vertically on the cornea (Fig. 84). The weighted stylet B
produces an indentation of the surface of the cornea, the depth of which is
measured by the movement of the pointer on scale SS. The lower the
tension of the eye, the deeper will be the depression. The number of
divisions of the scale is read off, begimiing at S on the left, and note
taken of the weight used, then, by reference to a chart (Fig. 85) which

/ ^

"-J^TX l/il

^ \ \A \A-

1 i >

1/0" / =

>^^ /

LL^'LJ

^^-

i E

r-r"

I E

; ~

: 1 1

mm.fin
130

Fig. 83. Tonometer
of Schiotz.

Fig 84. Tonometer of
Schiotz in use.

11 10 8 8 7 6 S 4 3 2 1
Deviations of Pointer

Fig. 85. Tonometer
Chart.

accompanies the instrument, the tension in millimetres of mercury is
found.

In using the instrument it is important to observe the following pre-
cautions : The eyelids must not touch the footplate, which should be
exactly in the centre of the cornea. The instrument must be quite vertical
and any upward or downward pressure of the collar C must be avoided.
The stylet must be kept clean (with alcohol or ether) so as to avoid friction
as much as possible. The most reliable results are obtained by using a
weight which wall give a reading between 2 and 6 on the scale.

Pulsation corresponding to the pulse rate is frequently transmitted to
the pointer in normal as well as in glaucomatous eyes. The continuous
application of the tonoineter for a short time lowers the tension, so also

238 DISEASES OF THE EYE. [chap. ix.

does massage of the eye. Axenfeld has observed a decided diminution of

the tension in glaucoma patients when under chloroform, except in cases
of very high tension, and he suggests that the absence of such a reduction
in the tension points to an unfavourable prognosis.

Other symptoms of glaucoma, as already stated, are due to the
increased tension ; but in chronic glaucoma there are fewer symptoms
than in acute glaucoma. Let us now describe these two great forms
of primary glaucoma separately.

And first as to Chronic Simple Glaucoma (also known as Simple
Glaucoma, and as Chronic Non-Congestive Glaucoma).

Symftoms. — Dimness of vision, gradually increasing, in the
affected eye, is the only symptom of which the patient with chronic
simple glaucoma usually complains. But some patients complain
of a permanent ' fog,' which yet does not reduce the acuity of
vision as measured with the test types ; while others have short
attacks of ' fog ' associated with the appearance of rainbow colours
around the flames of lamps or candles.

The tension is raised. Sometimes the eye is very hard (T -j- 2,
or more), and again it may be but slightly raised (T + 1). Even in
one and the same eye the tension usually varies, and may be at
one time too high, and at another almost, or quite, normal. Hence
it may be necessary to test the tension at different times before
a decision can be arrived at.

The external appearance of the eye is usually normal, and the
pupil reacts well to light. The anterior chamber is sometimes a
little too shallow.

On examination wdth the ophthalmoscope, the optic papilla is
found to be cupped ; because the optic disc, or, more correctly, the
lamina cribrosa, being the weakest part of the sclerotic, is the first
place to give way to increased intra-ocular tension. Consequently,
the lamina cribrosa being pushed back, the optic disc becomes
depressed, or cupped, and the cup becomes sometimes even deeper
than the outer surface of the sclerotic.

This cupping of the papilla (Plate IV.) is a most important sign
of glaucoma, and differs essentially in appearance from the physio-
logical cupping (p. 37), inasmuch as it occupies the entire area
of the papilla, and has steep, not shelving sides. As shown in
Plate IV. Fig. 4, the walls of the excavation are often hollowed
out, and the ophthalmoscopic effect of this is to give to the retinal

PLATE IV

{To face page 238)

Fig, 1. — 'the optic disc is atrophied and greyish white, and is surrounded
by a pale ring, the glaucomatous halo. The cupping is recognised by
the curving of the vessels, where they dip over the edge of the cup,
and seem to end abruptly, as well as by the paler appearance, and
displacement of the trunks of the vessels in the centre of the cup.

Fig. 2. — C, cornea ; S, sclerotic ; B, ciliary body, atrophied ; I, iris ; A,
anterior chamber ; L, lens. The iris is adherent to the cornea from
D to E.

Fig. 3. — Letters as in Fig. 2. The x is just above the canal of Schlemm.

Fig. 4. — N, optic nerve, atrophied, xx pointing to the only remaining
bundles of nerve fibres. S, Sclerotic ; Ch, chorioid ; R, retina, which
was partly separated in making the section ; C, deep cup ; V, a vessel,
with some others containing blood, below it.

Fig. 6. — From a case of ring-sarcoma of the ciliary body. Letters as in
Fig. 2. The cornea (C) has been partly cut away, x points to canal
of Schlemm and tributary vessels, all filled with pigment cells. I,
extension of growth into iris.

(For the micro-photos of sections represented by Figs. 2 and 3
we are indebted to the kindness of Professor O' Sullivan and Dr.
Wigham of the pathological department of Trinity College, Dublin.)

Plate IV.

Fig. 1. Glaucomatous Cup.

Fig. 2. Closure of Angle of Anterior
Chamber (Glaucoma).

Fig. 3. Angle of Anterior Chamber
in a Normal Eye.

Fig. 4. Glaucomatous Cup.

Fig. 5. Secondary Glaucoma with open

Angle, but obstructed Canal of

Schlemm, etc.

CHAP. IX.] GLAUCOMA. 239

vessels the appearance of being broken off at the margin of the
papilla (Plate IV. Fig. 1), where they pass round the overhanging
edge of the excavation, and become hidden by it, while on the
floor of the excavation they reappear.

The presence of an excavation may be recognised ophthal-
moscopically, in the examination by the indirect method, by means
of lateral motions of the convex lens. It will then be seen that,
while the whole fundus seems to move along with the motion of the
lens, the floor of the excavation apparently moves in the same
direction, but at a slower rate. This parallax is the more marked
the deeper the excavation, and is best seen by observing the margin
of the excavation. The phenomenon is explained by the accom-
panying figure (Fig. 86). If o be the optical centre of the lens
being used in the examination, and b and a two points lying one
behind the other, the inverted images of these points will be situated
at h^ and «>. The line r/^ ¥ lies in the visual line of the observer :

Fig. 86.

and if the lens be moved upward a very little, so that the optical
centre comes to o^, the inverted images of b and a will be removed
to ¥ and a^. If the observer have not altered his point of view,
it will seem to him that the point b has made a more extensive
motion than the point a ; or that it has moved more rapidly than
a, and has glided between a and the observer. Short and rapid
motions of the lens from side to side, or from above downwards,
will best show the parallax.

In examination by the direct ophthalmoscopic method, the
existence of an excavation may be ascertained, by observing that a

240 DISEASES OF THE EYE. [chap. ix.

lens of a dilferent power is required in order to obtain a clear image
of the margin of the papilla and of its floor. The depth of the
excavation may be estimated by noting the difference between these
two lenses — e.g. if the general fundus of the patient be emmetropic,
and the emmetropic observer require — 3 D to see the floor of the
excavation, the depth of the latter is about 1 mm., and in the same
proportion up to 10 D.

Besides being cupped, the optic papilla in glaucoma becomes
atrophied, and its consequent pallor serves to aid the diagnosis
between this and a physiological excavation.

If primary atrophy should attack an optic nerve in the disc of which
there is a physiological cup, the appearance presented may be identical
with that of a glaucomatous cup, and the diagnosis would then depend
upon other symptoms of each disease. (See p. 242.)

Spontaneous pulsation of the arteries on the optic papilla may
be often noted in glaucoma, or can be produced by slight pressm-e
on the eyeball with the finger ; because blood can only be forced
into these vessels by a pressure greater than that opposed to it.
Now% in an eye with normal tension there is no arterial pulsation —
and slight pressure with the tip of the finger does not bring it on —
for the arterial tension is greater than the intra-ocular tension ; and
therefore the blood flows in a continuous stream. But, in the
decidedly glaucomatous eye, the intra-ocular tension opposes so
great an obstacle to the arterial flow, that at the systole alone can
it make its way through.

Arterial pulsation also occurs, although rarely, in exophthalmic goitre
(chap. XX.) ; and it occurs where the pressure in the arteries themselves
is low (weak heart action, aortic regurgitation, etc.), even though that in
the vitreous chamber be normal.

Around the margin of the glaucomatous excavation, especially
in chronic glaucoma, one usually sees the whitish appearance,
termed the glaucomatous ring (Plate IV. Fig. 1), which is held to be
due to atrophy of the chorioid from pressure.

While increasing dimness of sight is the symptom of which the
patient chiefly complains in a case of chronic simple glaucoma, an
examination of the field of vision will show it to be contracted — the
contraction of the colour-fields preceding that for white — (Fig.

CHAP. IX.]

GLAUCOMA.

241

9) in consequence of interruption to tlie conduction in the retinal
nerve-fibres from pressure on them at the margin of the depressed
optic papilla. This contraction of the field must always be carefully

Left Field Right Field

Fig. 87. — Case of Glaucoma. Right Field (taken with perimeter) con-
tracted, especially at nasal side, so close up to fixation point that operation
was contra-indicated. V = 6/36. Left Field, as taken 3^ years after
iridectomy, contracted, especially at nasal side. V = 6/18. No further
contraction of field or loss of vision took place in this eye.

looked for with the perimeter in eight or ten meridians as it is most

important for diagnosis and prognosis. The contraction commences

at the nasal side as a rule

(Fig. 87), while at the same 20

time central vision is lowered,

and at a later stage the

temporal portion of the field

becomes contracted, and

gradually complete blindness

is brought about. In some

cases the field projects on the

nasal side above or below the

horizontal line (Fig. 88).

In addition to the exam-
ination of the field with the
ordinary perimeter, the field

should be further investigated by Bjerrum's method with a black
velvet screen two metres square and a test object about 2 mm.
16

fvmp^\

Fig. 88. Glaucomatous field in a
late stage showing nasal " step."

242

DISEASES OF THE EYE.

[chap. IX.

square or with Priestley Smith's scotometer. By this means the
state of relative vision within the field is examined. In glaucoma
the area of relative defect in the field can always be traced to the
blind spot, if a sufficiently small test object be used ; or, in other
words, the area of most acute vision, and that of relative defect,
meet at the blind spot. In some cases a crescentic para-central
scotoma which includes the blind spot may be found.

The diagnosis between glaucoma and primary atrophy of the
optic disc, which is sometimes difficult, may be made by this method
of examination of the field of vision. The examination of the field
of vision by the ordinary method does not always assist, for in each of
these diseases the field is liable to be contracted. Whereas Bjerrum's
symptom occurs with glaucoma, and not with primary atrophy.

The effect of a miotic on the intra-ocular pressure may aid the
diagnosis ; for while it would not materially influence the normal

tension in primary
Riffhi Field atrophy, it would re-

duce the high tension
in glaucoma.

The central colour
sense usually remains
normal in glaucoma
until a late stage,
but in primary optic
atrophy it is defective
at an early stage.

Again, if slight
pressure with the tip
of the surgeon's finger
during the ophthal-
moscopic examination
produce arterial pul-
sation at the optic
papilla, it is suggestive of glaucoma ; for in an eye with normal
tension, as already stated, considerable pressure is needed to pro-
duce this effect.

The progress of chronic simple glaucoma is extremely slow and
insidious, extending often over several years, and ending in total
blindness if untreated.

lenip

Fig. 89. — Case of Glaucoma. Right Field,
taken by Bjerrum's method. The contraction
of the field extends to the blind spot, which is
situated in the dotted portion of the figure.

CHAP. IX.] GLAUCOMA. 243

Acute Glaucoma. (Also called Acute Congestive Glaucoma.) —
In this form the Increase of Tension is always very marked. The
following symptoms are also found : —

Diminished Depth of the Anterior Chamber, from pushing for-
wards of the lens and iris.

Diminution of the Kefracting Power of the Eye, by reason of the
nearer approach of the latter to a globular shape.

Diminution of the Amplitude of Accommodation, and Anaes-
thesia of the Cornea, owing to pressure on the ciliary nerves as they
pass along the inner surface of the sclerotic.

Opacity of the Cornea, giving its surface a steamy or breathed-
on appearance, due to oedema of the corneal tissue and epithe-
lium.

A similar appearance is seen in interstitial keratitis.

Indistinctness of the Pattern of the Iris, similarly due to oedema.

Opacity of the Aqueous and Vitreous Humours.

Dilatation and Immobility of the Pupil, the result, according to
some, of paralysis of the ciliary nerves, but, according to others, of
anaemia of the iris from pressure on its vessels. The pupil is often
oval, with its long axis vertical.

The Episcleral, or Anterior Ciliary, Veins are large and tortuous
(Plate II. Fig. 4), owing to pressure on the ven^e vorticosae, w^hich
prevents the outflow by those channels of the chorioidal venous
blood, which must then pass off by the anterior ciliary veins.

Subjective Appearances of Light and Colour, and coloured halos
or rainbows around lamps and candles (iridescent vision) are com-
plained of.

Pain is a very marked symptom of acute glaucoma, both in
the eye and radiating over the corresponding side of the head,
and is often very violent ; and, in consequence of the pain and
of the injection of the eyeball, the term ' inflammatory ' is some-
times applied to congestive glaucoma, although there is no in-
flammation in the true sense.

Vision is greatly affected, and in cases of some standing the field
of vision, when it can be examined, will be found contracted.

The Optic Papilla, when the media are sufficiently clear to admit
of its being examined, is seen to be cupped, if the disease have con-
tinued sufficiently long to bring about this change.

244 DISEASES OF THE EYE. [chap. ix.

The pain, the injection, and the indistinctness of the iris stroma may
render a diagnosis from iritis not quite plain to a beginner ; and an error
would be serious, because the treatment is very different. In iritis the
pupil is contracted ; in acute glaucoma it is dilated and often oval from
above downwards. In iritis there are usually posterior synechias ; in
acute glaucoma there are none. In iritis the tension is nearly always
normal, and never high, while in acute glaucoma it is always markedly
raised. In iritis the anterior chamber is of normal depth ; in acute glau-
coma it is too shallow.

In acute glaucoma we recognise certain Premonitory Symptoms —
viz. sudden diminution of the amplitude of accommodation, evi-
denced by the rapid onset or increase of presbyopia, and the con-
sequent necessity for higher + glasses for near work ; and the
occasional appearance of coloured halos around the flames of lamps
or candles, with attacks of fogginess of the general vision. The
duration of one of these foggy attacks may be from a few minutes to
several hours. Such attacks are apt to occur after a sleepless night,
or after a meal, and are sometimes accompanied by peri-orbital
pains. Slight opacity of the aqueous humour, and sluggishness of
the pupil, with some dilatation, are present during an attack; but
the eye afterwards returns to its normal condition, and remains so
for weeks or months, until another similar attack comes on. The
premonitory stage may last a year or longer, but cases also occur in
which there is no premonitory stage.

The most favourable time for operative interference is during
this premonitory stage. The operation can then be performed
with technical accuracy in an eye free from congestion, and w4th a
normally deep anterior chamber. There is, too, as yet no loss of
sight, nor any degeneration of the tissues of the eyeball, and con-
sequently the operation can preserve full vision. The difficulty is
to induce patients to consent to operation at this period.

The onset of the True Glaucomatous Attack is usually at night.
It is accompanied by violent pain radiating through the head from
the eye, and by pericorneal injection, chemosis, and lacrimation.
The aqueous humour becomes cloudy, the anterior chamber shallow,
the iris discoloured, and the pupil dilated to medium size and of
oval shape, while the cornea becomes steamy and anaesthetic. The
patient frequently complains of subjective sensations of light, and
vision is very defective, or may be quite wanting. Vomiting very
frequently accompanies acute glaucoma.

CHAP. IX.] GLAUCOMA. 245

The latter fact leads to errors of diagnosis, the patient's ailment having
been taken to be a gastric derangement, while the ocular symptoms were
regarded as mere coincidences, such as a cold in the eye, neuralgia, etc.

An attack such as that just described may, to a great extent,
pass away in the course of a few days, but a complete remission
of all the symptoms does not again take place. Some defect of
central vision is left, or, it may be, some slight peripheral defect in
the field of vision ; the tension does not become quite normal again,
and the pupillary motions remain slightly sluggish. Another acute
attack of glaucoma comes on in the course of some weeks or months,
and it, too, may pass away, leaving the eye in a worse condition than
it found it. The attacks gradually become more frequent ; and if
in the intervals the eye be examined, the cornea and vitreous humour
will be found more or less opaque, the optic papilla cupped, and
pulsation of the central artery of the retina may be discovered.
Finally, there is no remission from the attack, the violent glauco-
matous symptoms become permanent, and all vision is for ever
destroyed.

Even when vision has been destroyed, the high tension con-
tinues, and gradually produces that disorganisation of the tissues
of the eyeball known as glaucomatous degeneration. The iris
becomes atrophied, the lens becomes opaque, and the cornea
frequently ulcerates, while hsemorrhages are apt to occur in the
anterior chamber. In time the excessive intra-ocular tension causes
staphylomatous bulging of the sclerotic in the ciliary region, or
farther back ; and finally, these eyes may become the subjects
of acute purulent chorioiditis, ending in phthisis bulbi.

Acute glaucoma almost always comes on in both eyes, either
at the same time, or with an interval, it may be of weeks, or of
months.

The reason for the marked difference between the symptoms
and course of chronic and of acute glaucoma is, probably, that in
the former the increase of tension is very gradual, and therefore
the eye gradually becomes accustomed to it ; while in acute glau-
coma the increase is rapid or sudden, and the circulation of the eye
has not time to accommodate itself to the new state of things.

Glaucoma Fulminans is the term given to a form of the disease,
which is more acute than the ordinary acute glaucoma just described.
It has no premonitory stage, and, coming on with all the symptoms

246 DISEASES OF THE EYE. [chap. ix.

of acute glaucoma greatly intensified, does not remit, and causes
complete permanent destruction of vision in the course of a few
liours. It is very rare.

Subacute Glaucoma. — This form differs from acute glaucoma,
in that its premonitory stage merges gradually into the actual
disease, without the occurrence of an acute attack. The eye gradu-
ally becomes hard, the pupil dilated, the anterior chamber shallow,
the aqueous humour opaque ; while the cornea is ' steamy ' and
aUcTsthetic, and the episcleral veins are distended. With the ophthal-
moscope the cupped disc and pulsating arteries may be seen,
when the opacities of the media permit. Vision sinks, and the
field is contracted towards its nasal side. The progress of the disease
is very slow ; and in its course attacks of ciliary neuralgia, with
greater increase of the tension, greater opacity of the aqueous
humour, increase of the corneal opacity and anaesthesia, and in-
creased dimness of vision, are experienced. These attacks pass ofi
in the course of a few days or hours, leaving the eye harder and
blinder than before. The subacute glaucoma sometimes takes on
the acute form. It is liable to bring about the same glaucomatous
degeneration of the eye as does the latter.

Etiology of Glaucoma. — Glaucoma is a disease of advanced life,
occurring most usually after fifty years of age, and rarely und«r the
thirtieth year. It is sometimes hereditary, and may then make
its appearance at an earlier age in the succeeding generations. My-
opic eyes are less liable to it than hypermetropic, or emmetropic
eyes. The congestive forms are more common in women than in
men.

Anxiety, sorrow, and influences in general which depress the
spirits have often been noticed to precede the onset of acute glau-
coma. Causes which tend to dilatation of the pupil may also pre-
cipitate an attack.

Pathology of Glaucoma. — The theory of this disease which obtains
very general acceptation is known as the Retention Theory.

In the normal eye the intra-ocular fluids are being constantly
renewed, and they must as constantly escape from the eyeball. Their
exit is mainly by way of the sinus venosus, or canal of Schlemm,
situated in the angle of the anterior chamber (anterior way of exit).
The spaces of fontana are separated from the sinus venosus by a
delicate wall which consists of a layer of endothelium only. Again,

CHAP. IX.] GLAUCOMA. 247

the intimate union of the distal aspect of the blood-vessel with the
tissue of the sclerotic keeps it patent, and in this way the constant
outflow of the fluids is assured. Hence the most favourable ana-
tomical conditions for filtration are present at the angle of the
anterior chamber. Moreover, physiological experiment has shown
that the intra-ocular fluids do escape by this path. It is true that
the aqueous humour and other intra-ocular fluids escape, also,
through the veins on the anterior surface of the iris, and through
the veins of the ciliary body, into the venae vorticosse (posterior
ways of exit) ; but it is tolerably certain that the main exit is
through the canal of Schlemm, at the angle of the anterior chamber.

Now, it has been ascertained that, in glaucomatous eyes, the
root of the iris is pushed forwards, and lies in close contact with the
periphery of the cornea ; thus effectually sealing the angle of the
anterior chamber (Plate IV. Fig. 2), so that no fluid can escape
through the spaces of fontana and canal of Schlemm. The intra-
ocular fluids must then be retained in the eye, and its tension
must be increased ; or, in other words, it must become harder
than it is normally. But what the factor is which brings about
the peripheral adhesion of the iris is an obscure question on which
opinions are divided.

Priestley Smith is of opinion that the chief predisposing cause
of primary glaucoma is an insufficient space — the circumlental
space — between the margin of the lens and the structures which
surround it, and to the progressive increase in the size of the lens,
which he has shown to occur as life advances, he attributes the
greater liability of elderly people to glaucoma.

In eyes in which the circumlental space is insufficient, by reason
either of the original structure of the eye (and small eyeballs are
specially liable to primary glaucoma, a fact often demonstrated by
the small size of the cornea in the eyes attacked) or of the enlarge-
ment of the lens, any condition which tends to overfill the veins of
the head and uveal tract may initiate an attack of acute glaucoma,
as follows : —

An increase in the amount of blood in the uveal tract must be
compensated by the expulsion of some other fluid from the eye ;
consequently, the aqueous humour filters out more rapidly than is
normal at the angle of the anterior chamber. As the contents of
the chamber diminish, the lens and iris move forwards towards the

248 DISEASES OF THE EYE. [chap. ix.

cornea. Now, in the normal eye, and especially in the youthful eye,
this compensation is effected without danger to the angle of the
anterior chamber, because the lens is comparatively small, the
circumlental space large, and the anterior chamber deep. But,
when the lens and ciliary processes are already in close relation to
each other, and the anterior chamber is already shallow, then any
increased fullness of the uveal tract involves danger to the angle of
the chamber. The turgid ciliary processes find insufficient space
for their expansion ; they are carried forwards together with the
lens, and, pressing upon the base of the iris, lock up the angle of the
anterior chamber. Thereupon, the further escape of fluid being
impossible, high tension of the eyeball is established.

According to this explanation, then, the high tension is due to
impeded escape of the intra-ocular fluid (the retention theory), and
depends, primarily, upon an increase in the amount of blood in
the eye. Priestley Smith considers that, in chronic simple glaucoma,
the predisposing causes are the same as in acute glaucoma ; but
that in the former, the vascular disturbance being gradual and
slight, the vessels adapt themselves to the slowly increasing
pressure, and the angle of the anterior chamber is more or less
compressed, but not tightly closed.

Thomson Henderson has advanced a theory of glaucoma very
different from that generally held. There are, he believes, two factors
in glaucoma : — a constant predisposing one — namely, sclerosis of
the ligamentum pectinatum, preventing access of the aqueous
to the canal of Schlemm, the chief normal outflow of the aqueous —
and an immediate exciting one, which is vascular. The explanation
of the way in which a rise in the general blood pressure leads to an
increase of the intra-ocular tension is based on the assumption that
the eyeball is a closed and unyielding capsule, the volume of the
contents of which is a fixed quantity — an assumption which, to say
the least of it, requires proof.

Amongst other local causes to which glaucoma has been attri-
buted are abnormal rigidity of the sclerotic and obstruction of the
venae vorticosae either by pathological changes in their walls or by
compression near their point of exit.

It is very probable that glaucoma is due to the combination of
a local peculiarity in the eye itself, with some general constitutional
derangement. Sometimes the patients are neurotic and excitable^

CHAP. TX.] GLAUCOMA. 249

or there may be arterio-sclerosis, high arterial tension, cardiac dis-
ease, or renal insufficiency.

Treatment. — In the treatment of glaucoma, with rare exceptions,
an operation becomes necessary. The performance of an iridectomy
is the means discovered by von Graefe, in the year 1857, for the cure
of glaucoma, a disease which had hitherto been incurable.

To ensure the success of an iridectomy for glaucoma, so far as
is possible, it is necessary (1) that the incision should be peripheral —
i.e. as far back in the corneo-sclerotic margin as is compatible with
the introduction of the knife into the anterior chamber, and with
the avoidance of injury to the ciliary body ; (2) that the portion
of iris removed should be wide — i.e. involving about one-fifth of the
circumference of the iris (Fig. 79) ; and (3) that it should be abscised
as peripherally, i.e. as close to the root of the iris, as possible.

It is, moreover, important to withdraw the knife very slowly
from the anterior chamber, when the corneo-scleral section is com-
plete, in order that the aqueous humour may flow off gradually, lest
an intra-ocular haemorrhage from the sudden reduction of tension
should occur.

The portion of iris should be most carefully abscised, so that no
tag of it may remain in the wound and become caught in the cicatrix
in the course of healing. Such an occurrence is apt to produce a
cystoid cicatrix, which may at a later period become the starting-
point of irritation, and even of serious inflammation. Some opera-
tors prefer von Graefe's cataract knife for the performance of the
operation, but the lance-shaped keratome is the instrument usually
employed.

For the purpose of reducing the intra-ocular tension, it matters
nothing what region of the iris be abscised ; but, as a rule, the
upper quadrant is to be preferred, for there the resulting coloboma,
being covered to a great extent by the upper lid, will give rise to less
diffusion of light than in any other position.

Immediately after the operation, palpation of the eyeball should
show a marked diminution of tension. When this is not so the
prognosis is unfavourable. Should an increase of tension occur on
the day after the operation, it is of no consequence, as it passes off
again in the course of the next few days. Until then, the anterior
chamber will not be restored, and we see cases where the anterior
chamber does not appear for a week or more. The bandage should

250 DISEASES OF THE EYE. [chap. ix.

be worn until the anterior chamber is completely restored. It is
desirable to perform the operation with general anaesthesia, to secure
technical accuracy. The pain for some time after the operation is
considerable, and should be relieved by a hypodermic injection of
morphia in the corresponding temple.

Malignant glaucoma is the term applied to certain rare cases,
in which immediately after iridectomy, although the operation
may have been faultlessly performed, the lens is violently pushed
forwards, blocking the wound, obliterating the angle of the anterior
chamber, and preventing any fluid fi'om escaping from the eye, so
that it is soon as hard as, or harder than, before ; and the condition
is accompanied by cloudiness of the cornea, injection of the blood
vessels, chemosis, violent pain, and great loss of sight. This com-
plication seems to be caused by the retention of fluid behind the
lens, and is more likely to occur in cases of chronic simple glaucoma,
than in the acute forms of the disease. The only prospect of saving
eyes which take this malignant course is by the operation of posterior
sclerotomy. A broad needle, or a Gr?efe's knife, is entered through
the sclerotic, 8 or 10 mm. behind the outer margin of the cornea,
and the blade is given a quarter turn on its axis, so as to make
the wound gape, or the latter may even be somewhat enlarged in a
meridianal direction. At the same time gentle pressure is applied,
by means of the upper lid, on the centre of the cornea. This causes
fluid to escape through the scleral wound by the side of the knife,
and it also causes the lens to go back into its place, with restoration
of the anterior chamber. The pressure on the cornea may be main-
tained with advantage for a minute or somewhat longer. This
operation is also very useful as a preliminary to iridectomy in cases
where the anterior chamber is obliterated.

The therapeutic value of a correctly performed iridectomy for
glaucoma depends mainly on the form of the glaucoma — congestive,
or chronic simple — for which the operation is performed. The more
congestive or acute the case, the more favourable is the prognosis
in respect of the result which may be expected from the operation ;
and hence the congestive forms are more favourable for operation
than the simple chronic form.

In the congestive forms, the operation may be expected with
great certainty to preserve permanently whatever vision remains,
and it can restore the gi'eat loss of sight dependent on an attack of

CHAP. IX.] GLAUCOMA. 251

acute congestive glaucoma, if performed without delay. It will not,
in these acute cases, restore vision which has been lost for a few days.

But in chronic simple glaucoma, when the disease has advanced
so far that the contraction of the field has approached close to the
fixation-point, although central vision may still be fairly good, the
prognosis must be very guarded. Because in such cases, while the
iridectomy may prove successful in so far as reduction of tension is
concerned, yet the contraction of the field — i.e. the progress of the
atrophy of the optic nerve — is often hastened. Indeed, where the
contraction is near the fixation-point at one side (Fig. 87), and is
advanced in other directions, iridectomy is contra-indicated in
chronic simple glaucoma.

Yet, in the early stages of chronic simple glaucoma, while central
vision is as yet unaffected ; the field of vision, not at all, or only
slightly contracted ; and the optic disc although somewhat cupped,
yet not advanced in atrophy, an iridectomy may save the sight per-
manently. Even at a later stage, with some contraction of the
field and a certain amount of atrophy, some vision is often saved,
or blindness is retarded.

A falling away in vision must be expected in almost all cases of
chronic simple glaucoma after the iridectomy ; but in the favourable
cases this is only temporary, and the sight gradually returns to its
previous state in the course of some weeks.

In cases of acute or subacute glaucoma, it has frequently been
observed that shortly, even within a few hours, after the perform-
ance of the iridectomy, the other eye, previously healthy, or, at most,
affected with but slight premonitory symptoms, is attacked with
glaucoma. It is probable that this is due to dilatation of the pupil,
with pressing of the iris into the angle of the anterior chamber, in
consequence of confinement in the dark room and to the mental
anxiety attending the operation, and eserine should be put into
the sound eye as a precaution.

The Mode of Action of the Operation, it is believed, consists
not so much in the removal of the portion of iris, as in the nature
of the sclero-corneal wound, which in successful cases results in the
establishment of a sclero-corneal fistula opening into the anterior
chamber and through which the intra-ocular fluids flow away.
When an iridectomy is done, the small portion of the root of the
iris which is left, becomes folded into the wound and tends to

252

DISEASES OF THE EYE.

[chap, IX.

prevent a solid closure. This view is supported by Priestley Smith
and Treacher Collins.

In those cases where a fistula, as described, is not formed by the
operation, Collins considers that the obstruction to the outflow of
lymph becomes freed, either by the iris being torn away at its thinnest
part — that is, its extreme root — thus leaving a large portion of the
filtration angle open for drainage ; or, by the escape of the aqueous
and the drag on the iris, incidental to the iridectomy being insufficient
to dislodge the periphery of an iris, which has only recently come
into apposition with the cornea.

Lagrange, believing in the necessity of providing a permanent
drainage of the anterior chamber, first introduced a method for
establishing a subconjunctival fistula, without any inclusion of the
iris. The essential part of his operation consists in the excision
of a small piece of sclerotic at the sclero-corneal margin (sclerectomy).
Various other procedures have lately been devised for the accom-
plishment of the same object.

These operations are not intended so much for the congestive
forms of glaucoma, in which iridectomy is quite satisfactory, as for
the chronic forms.

1. Anterior Sclerectomy (Lagrange's Operation). — At least half
an hour before the operation the pupil is contracted with a miotic.
A Gr£efe's knife is entered about 1 mm. from the corneal margin,

and the counter punc-
ture is made at a cor-
responding point at the
opposite side ; but the
incision should not be
so long as that for a
cataract extraction.
The incision is then
carried upwards into
the irido-corneal angle ;
and, when it is about
to be completed, the edge of the knife is directed somewhat back-
wards, so as to bevel the centre of the sclerotic incision in cutting
out, and finally a large conjunctival flap is formed (Fig. 90). The
conjunctival flap is then lifted with a forceps, and drawn down-
wards (Fig. 91) ; and, with suitably curved and very sharp scissors,

Fig. 90.

r!HAP. IX.]

GLAUCOMA.

253

Fig. 91.

a sufiiciently hirge piece of the sclerotic is resected from the lower,
or corneal, edge of the wound, and the conjunctival flap is spread
over the incision. A
punch may be used
instead of the scis-
sors for the resection
of the sclerotic
(Holth).

This operation is a
simple sclerectomy.
I f necessary the
operation of sclero-
iridectomy is done,
and then the iridec-
tomy may be made

in the ordinary way ; or preferably, only a peripheral button-hole is
made by simple incision into the iris, or by excision of a small piece
near the base of the iris. The button-hole iridectomy prevents
prolapse of the iris quite as well as, or even better, than the excision
of the whole piece of the iris, and the preservation of the sphincter
enables miotics to act with better effect, if it be required to use them.

In the cases with rather high tension, sclerectomy should be
combined with an ordinary iridectomy. In lower degrees of tension,
if there is tendency to prolapse of the iris a button-hole iridectomy
will suffice, and it should also be resorted to in cases where the con-
traction of the field approaches close to the fixation point. Simple
sclerectomy should be reserved for chronic simple glaucoma with
intermittent or slight increase of tension.

2. Sclerectomy with the Trephine {Elliot's Operation ^). — The pupil
having been contracted by eserine, the patient is told to look down ;
the conjunctiva is then seized as high up on the globe as possible, and
with scissors a large conjunctival flap is made concentric with the
corneal margin and ending at each side about 8 mm. away from the
limbus (Fig. 92). The conjunctiva is next dissected down to the

^ The operation of trephining for glaucoma was done independently
in the same year by Freeland Fergus and Colonel Elliot. As a matter
of fact, Fergus's first operation preceded Elliot's in point of time, but it
is to the latter that we owe the details of the operation as it is performed
at present.

254

DISEASES OF THE EYE.

[chap. IX.

limbus, but only in the centre (bh, cc, Fig, 92) ; the loosely adherent
conjunctiva in the triangles abc help to keep the flap in position

after the operation. As the dis-
section approaches the limbus, the
sclerotic should be laid bare. With
the points of the closed scissors the
limbus should now be well defined,
as a rounded ridge slightly over-
riding the sclerotic. The flap is
pushed gently down, out of the
way, with the closed forceps so as
not to tear it, and with a sharp,
pointed scissors or a Bowman's
needle the superficial layers of the
cornea are separated until a dark
crescent 1 or 2 mm. broad {cc,
Fig. 92) makes its appearance. Any
connective -tissue tags are now
cleared away from the sclerotic and
a 2 mm. trephine (Fig. 93) is ap-
plied as far forwards as possible, so that its edge w^ill just clear
the flap, and so avoid button-holing it; the lower end of the
trephine, if necessary, may be steadied with a forceps or with the
guide provided. In rotating the trephine the pressure should
be a little greater on the corneal side, as it is thicker than the
sclera here. After a few turns the trephine may be removed to see
the position of the circular groove made ; it can easily be replaced
again. When the anterior chamber is entered, the aqueous wells

Fig. 92. abb a, line of con-
junctival incision ; bb cc, area of
dissected conjunctiva ; abc,
triangles of conjunctiva left
attached ; ccdd, approximate
area in which sclerotic is laid
bare. The crescent of cornea
above cc is the portion exposed
by " splitting " when the flap is
reflected down ; t, trephine hole.

Fig. 93, Elliot's trephine, with " chuck " for grasping the blade.

up round the instrument, there is a slight sucking feeling, the pupil
becomes displaced upwards, and the patient feels a momentary
sensation of pain. The disc usually remains attached by a small
hinge, which should be preferably on the scleral side, and in most
cases the iris prolapses. The disc of sclera is now grasped with the

CHAP. IX.]

GLAUCOMA.

255

special forceps (Fig. 94) and both it and the prolapsed iris are snipped
off together with a sharp- pointed iris scissors, with the result that
a complete, or only a button-hole, coloboma is made (Fig. 96). In
carrying out this part of the operation, the still adherent disc steadies
the eye and prevents the dragging on the iris which would result if

Fig. 94. Elliot's disc forceps.

the iris were excised separately. If the pupil is not central or iris
tissue is engaged in the trephine hole an irrigator is used. The flap
is then replaced, no suture being required as a rule. Atropine is
put into the eye on the third day or even earlier, owing to the
tendency to slight iritis.

Figs. 95 and 96 show two different degrees of subconjunctival
filtration after trephining. This operation gives on the whole excellent
results. If tension recurs it may be due to the following causes : —
placing the trephine hole too far out ; blocking of the hole by uveal

Fig. 95. Trephine operation
with slight subconjunctival oedema
over the site of the trephine hole,
which appears as a faint dark spot.
Taken one year after operation.

Fig. 96. Trephine operation
with more marked conjunctival
swelling. Peripheral iridec-
tomy. Taken one year after
operation.

tissue, or by the proliferation of uveal or connective tissue ; and
plugging of the hole by lens or vitreous. Occasionally the disc
removed by the trephine is cut clean out and may get into the

256 DISEASES OF THE EYE. [chap. ix.

iiuterior cliamber, but should this happen it can be washed out with
an irrigator, or can be removed with a very fine, sharp hook, if
necessary, as we have done in two instances. It should be stated
here that a few cases of late infection of the eye have been recorded
in cases operated on by sclerectomy or trephining, the micro-organism
probably effecting an entrance through a defect in the conjunctival
covering of the wound.

The two operations just described are those which have met with
the greatest approval as substitutes for iridectomy. Other opera-
tions having the same purpose are : —

3. The Small Flap or Trapdoor Operation (Herbert). — Acting on the
idea that trephining and sclerectomy sometimes produce too great a dim-
inution of the tension, Herbert simply makes a trapdoor
ilZh—p at the sclerocorneal junction (Fig. 97, F).
/^ \ The transverse incision is first made with a bent

( O 1 keratome and then the lateral incisions with a narrow

V y cataract knife or with Harman's twin scissors. The fil-

tration is brought about, probably by defective union of
Fig. 97. the flap, owing to shrinkage or forward displacement.

4. Iridencleisis {Holth's Operation). — This consists in
subconjunctivally drawing one of the pillars of the iris, after iridectomy,
into the wound and allowing it to become incarcerated there, so as to
form a cystoid cicatrix. There is always a danger of late infection or
even of sympathetic ophthalmia in such a method of producing filtration.
5. Cyclodialysis {Heine's Operation). — The object of this operation
is to make a commmiication between the supra-chorioidal lymph space
and the anterior chamber, by separating the ciliary body and the root
of the iris from the ligamentum pectinatum, whereby freer drainage for
the intra-ocular fluids may be provided, by way of the posterior exits
which are not occluded.

The pupil having been contracted with eserine, the operation is per-
formed as follows : — About 5 mm. from the corneal margin the conjunctiva
is separated from the sclerotic ; then, with a straight lance-shaped knife,
which is held vertically like a pencil, an incision 2 mm. long is made,
through the sclerotic, as deep as the ciliary muscle, but without injury
to the latter. A thin spatula, or stiletto, is now introduced through the
opening and passed forwards, being kept close to the inner surface of the
sclerotic, until it reaches the ligamentum pectinatum through which it
is pushed into the anterior chamber. By lateral motions of the spatula
the dehiscence can be extended according to the operator's judgment,
and it is desirable it should be carried to about one-third of the circum-
ference of the anterior chamber. If the spatula be slowly withdrawn,
no aqueous humour is lost, and in that case a reduction of tension is not
observable until a day or two after the operation. If some immediate
reduction of tension be desired, more or less aqueous is caused to flow

CHAP, ix.j GLAUCOMA. 257

away. The operation is recommended for chronic simple glaucoma,
htemorrhagic glaucoma, and hydrophthalmos (p. 2G0). It is more painful
than iridectomy.

The Non-Operative Treatment of Glaucoma. — The miotics eserine
and pilocarpine as eye-drops in 1 per cent, solutions often reduce
glaucomatous tension. Their action depends on the contraction
of the pupil, and consequent drawing away of the base of the iris
from the angle of the anterior chamber ; and, if the miotic does
not contract the pupil well, it will not reduce the tension. Cases
of acute glaucoma, brought on by the injudicious use of atropine,
may frequently be completely and permanently relieved by a miotic
instilled a few times.

In acute congestive glaucoma the use of a miotic in the pre-
monitory stage will often postpone the true glaucomatous attack, and
even sometimes relieve the latter for the time ; but the miotic
treatment cannot produce a radical cure, and it should only be used
to preserve the health of the eye, until the operation is performed.

In chronic simple glaucoma, too, miotics bring down the ten-
sion when they contract the pupil, and may be used in those cases
where the patient positively declines an operation, or where an
operation in the fellow eye has not resulted satisfactorily, or where
an operation is contra-indicated by a very contracted field. The
anti-giaucomatous action of the miotic only lasts so long as the
pupil is contracted, and it must consequently be applied once or
twice in twenty-four hours. The miotic treatment, as a rule, can
only be regarded as palliative, yet cases are on record in which
such treatment has succeeded in preserving vision for a great many
years. Too great a reliance must not be placed on them, however,
and if during their use in the early stages of the disease any further
contraction of the field should take place, or the tension should
remain high, then recourse must be had to operation. Along with
the use of miotics, errors of refraction should be corrected, especially
hypermetropia, and the eyes should not be overtaxed in the matter
of reading or close work.

With regard to constitutional treatment, glaucomatous patients
should regulate their mode of living, and lead a quiet life, free from
mental excitement. They should also avoid excessive bodily
exertion. Their diet should be simple, and moderation should be
observed in the use of alcohol and tobacco. Sleeplessness, if present,
17

258 DISEASES OF THE EYE. [chap. ix.

must be combated. The administration of bromides in nem'otic
patients, and of potassium iodide in cases of arterio-sclerosis, may
also be of service. In acute cases, pending or preceding operation,
a free purge should be given ; and for the relief of pain, dionine in
powder applied to the eye, morphia given hypodermically, and leeches
applied to the temple are very useful measures.

It may be here once more stated that, while miotics possess the
power of reducing glaucomatous tension, atropine, and all my-
driatics, bring on glaucoma where there is already a tendency to it.
In all old people, therefore, before atropine is used, it is well to
ascertain that the tension is not high.

Treatment of Painful Blind Glaucomatous Eyes. — Eyes blind
of acute glaucoma may, as has been stated, continue to be pain-
ful, and to render the patient's life very miserable. If curative
operations fail, excision, or evisceration, must be resorted to.

Secondary Glaucoma.

In addition to the different forms of primary glaucoma above
described, we find, as already stated, that high tension occurs as a
sequel of diseased conditions previously existing in the eye. There
are several diseased states which are liable to become complicated
with glaucomatous tension ; but it should be clearly understood
that, in almost every instance, the immediate cause of the high
tension is the same as in primary glaucoma — namely, a closure of
the angle of the anterior chamber.

The following are the chief conditions which are liable to lead
to secondary glaucoma : —

a. Complete Posterior, or Ring Synechia (p. 175). The iris,
being pushed forwards by the aqueous humour pent up in the
posterior part of the aqueous chamber, is pressed tightly against
the cornea, and obliterates the angle of the anterior chamber and the
ways of exit. An iridectomy or transfixion of the iris relieves the
high tension here.

h. Perforating Wounds or Ulcers of the Cornea, followed by
incarceration of the iris in the resulting cicatrix. The iris, being
drawn tautly towards the cornea, a large portion, or the whole, of
the filtration angle may be closed by it. An iridectomy is indicated.

c. Dislocation of the Crystalline Lens into the Anterior Chamber.

CHAP. IX.] GLAUCOMA. 259

Here the iioriiicil How of the iutra-ocular fluids through the pupil,
towards the filtration angle, is arrested by reason of the presence of
the lens in the anterior chamber. The onward current then presses
the iris against the posterior surface of the lens, and the root of the
iris, whicli is unsupported by the lens, against the periphery of the
cornea, and in this way the angle of the anterior chamber is closed.
In these cases the lens must be removed from the eye.

d. Lateral (traumatic) Displacement of the Crystalline Lens.
The lens, being pushed in between the ciliary processes and the
vitreous humour, drives the root of the iris forwards against the
cornea at that place, while in other parts of the circumference
the displaced vitreous acts in the same way. In these cases, too, the
lens must be removed.

e. Traumatic Cataract. The swelling lens pushes the iris forwards
against the angle of the anterior chamber. Evacuation of the lens
should be performed.

/. After Cataract Extraction. For explanation of this see
p. 286.

g. Intra-ocular Tumours (p. 219). The growth of the tumour
gives rise to a transudation of serum from the chorioid which
detaches the retina, and after a time pushes the lens, the ciliary
processes, and the iris forwards, and thus closes the filtration angle.
In other cases the ligamentum pectinatum and canal of Schlemm
may be blocked by tumour cells (Plate IV. Fig. 5).

h. Serous-Cyclitis, or Iritis. Here the filtration angle is not
closed. But the filtration-power of the eye is diminished, perhaps
by tissue changes around the filtration angle, as well as by the
albuminous exudation in the anterior chamber.

Another, and peculiar, form of secondary glaucoma is Hsemor-
rhagic Glaucoma. Retinal haemorrhages, usually due to thrombosis
of the central vein, are sometimes followed, a few weeks later, by
increased intra-ocular tension, which generally assumes the symptoms
of acute or subacute glaucoma, and, more rarely, those of chronic
simple glaucoma. A satisfactory explanation for these cases has
not been offered. When such a glaucoma becomes pronounced,
it is not usually possible to distinguish it from a primary form of
the disease. This disease is practically hopeless. Iridectomy is
more likely to do harm than good, the operation being almost in-
variably followed by fresh intra-ocular haemorrhages, and by a further

260

DISEASES OF THE EYE.

[chap. IX.

increase of tension. Sclerotomy is said by some to be followed by
fairly good results ; but the miotic treatment is ineffectual.

Congenital Hydrophthalmos.

This disease, also known as Buphthalmos, and as Cornea Globosa,
is glaucoma of early childhood, tlie incipient stages of which are
intra-uterine. The eyeball is enormously
enlarged (Fig. 98), the cornea very much
wider than normal in its diameter, the
anterior chamber deep, the iris trembling,
and the sclerotic thinned. Increase of
tension and cupping of the optic papilla
are usually present, and there is severe
pain if the tension become high. This
disease is sometimes seen in association
with neurofibromatosis.

The Pathology of the disease is obscure.
Treacher Collins holds that it is caused by
a failure in the separation of the iris from
the back of the cornea at its extreme
periphery, in course of the development of
the eye ; E. von Hippel believes it to be
the result of an intra-uterine inflamma-
tion ; while Seef elder's investigations lead
him to regard it as due to mal-development of the ways of exit of
the intra-ocular fluids. In many cases there is more or less complete
absence of Schlemm's canal.

Treatment. — This disease is not very amenable to treatment.
A few cases of spontaneous recovery have been recorded. Iridectomy
sometimes arrests the disease, but often does harm. A few good
results have been obtained with the '' trapdoor " operation and
with the trephine. When the disease is very advanced, treatment
is of no avail except for the relief of pain.

Fig. 98. Congenital
Buphthalmos in the right
eye. The cornea of the
left eye was larger than
normal.

CHAPTER X.

DISEASES OF THE CRYSTALLINE LENS.

The crystalline lens, being an epithelial structure like the hair or
nails, is not subject to inflammation, the changes which take place
in it being degenerative in character. It is enclosed in a capsule
which is continuous round its margin, although for convenience of
reference we speak of the anterior and the posterior capsule. The
inner or lental surface of the anterior capsule is alone lined with
epithelium, which under certain conditions may proliferate. The
lens is bathed by the aqueous humour from which it derives its
nutrition by osmosis, through the capsule, and the integrity of the
latter is essential to the preservation of the transparency of the lens.

The only structures in contact with the lens are the vitreous
h umour behind and the pupillary portion of the iris in front. It is
suspended by the zonule inside the ring formed by the ciliary pro-
cesses, but is separated from them by an interval, the ' circum-
lental space.' The margin of the normal-sized lens is never visible,
even with a dilated pupil. Degeneration of the lens gives rise to
the opacity called cataract, and proliferation of the capsular epi-
thelium causes capsular cataract.

Apart from cataract the only abnormalities of the lens which
require consideration are dislocation and malformations. Cataract
may be complete — occupying, in its final stage, the w^hole, or nearly
the whole, of the lens ; or partial — occupying only part of the lens,
and with little or no tendency to extend to other parts of it.

Complete Cataracts.

Of these, the most common is Senile Cataract. It occurs in
persons of over fifty years of age, rarely in those under forty-five
years of age.

Progress, Pathogenesis, and Etiology of Senile Cataract. — In

261

262 DISEASES OF THE EYE. [chap. x.

incipient senile cataract, the opacity is found : — a. In the cortical
layers of the lens, especially at its equator, and in the latter position
can often be detected only with transmitted light from the ophthal-
moscope mirror, or with focal illumination, even if the pupil be
dilated with atropine. This opacity takes the form of trian-
^^ular sectors, of which the bases are towards the equator of the
lens, while the apices are towards its centre. These lines or sectors
look bhxck with transmitted light, but grey with focal illumination,
and between them clear lens-substance is present. These opacities
begin most frequently in the lower inner quadrant of the lens. Or,
h. Incipient cataract may appear as a diffuse opacity in the layers
surrounding the nucleus of the lens. Or, c. The opacity may com-
mence both near the equator and around the nucleus at about the
same time. Or, d. The opacity may in the beginning be dissem-
inated through the cortex, in the form of flocculi, dots, and lines.
e. In some cataracts, in a very incipient stage, there are no absolute
opacities ; but with weak transmitted light — i.e. from a plane oph-
thalmoscope mirror — numbers of fine dark lines will be seen in the
lens, which vanish and reappear according as the incidence of the
light is altered ; while not until later do true opacities make their
appearance. Gradually the cataract extends to other parts of the
lens, until the whole cortical portion is opaque.

In senile cataract, the very nucleus itself does not become cata-
ractous,- although it is usually sclerosed (harder and drier).

Sclerosis of the nucleus of the lens is a physiological condition of
advanced life, and will be found in many an eye where there is no
cataract. It gives to the senile non-cataractous lens, as seen with
a dilated pupil or with focal illumination, a peculiar smoky appear-
ance, which is often mistaken by inexperienced persons for cataract ;
but examination with transmitted light will show that there is no
true opacity. When a senile cataract has become complete, the
sclerosed nucleus imparts to its centre a brownish or yellowish hue,
while the other parts of the lens are of a greyish white. As a rule,
the most peripheral layers of the cortex are the last to become
opaque. Accordingly as the lens/l)ecomes opaque, it often swells
slightly ; and when this occurs the anterior chamber becomes a
little shallower.

Until the whole cortex is opaque, a clear interval will be present
between the iris and the cataractous part ; and, on examination

CHAP. X.] THE CRYSTALLINE LENS. 2G3

with the oblique light, a shadow of the iris will be thrown on the
cataractous part at the side from which the light comes ; and the
cataract, in this way, is proved to be immature in the strict sense.
If the whole cortical substance be opaque, the thickness of the
capsule alone will intervene between the pupillary margin and the
opacity, and no shadow of the iris can be thrown on the latter.

In addition to this examination with focal light, the pupil should
be dilated, and the lens examined by transmitted light from the
ophthalmoscope mirror, when a completely opaque cataract should
permit of no red reflection being obtained, in any direction, from
the fundus oculi.

As soon as the whole of the cortical substance has become
opaque, any swelling of the lens which there may be subsides, and
the anterior chamber finally regains its normal depth. If there be
no glittering sectors in the cortex, the cataract is now mature, or
' ripe ' for operation — that is to say, if an extraction operation be
now undertaken, the lens will be with great certainty delivered in
its entirety ; whereas, prior to this stage, cortical substance would
have been more liable to adhere to the capsule, and to be left behind.

But a cataract is immature, notwithstanding the absence of iris-
shadow and of the illuminable pupil, and even though the anterior
chamber be of normal depth, if the cortex present well-marked
glittering sectors. The glitter of the different sectors varies with
the angle of illumination, so that the surface appears facetted. In
such a lens there are thin transparent flakes, as well as opaque flakes,
close beneath the capsule ; and, if an extraction operation be under-
taken, the transparent portions are very apt to remain within the eye,
in spite of every attempt to remove them. A few months later
the sectors lose their sharp contour, break down, and finally dis-
appear. We can then depend upon the exit of the whole cataract.

Yet in persons over sixty years of age, in whom the nucleus is
usually large, many a cataract can be completely removed which
does not come up to the strict standard of maturity just laid down ;
and, at that time of life, the surgeon need not hesitate to operate,
without waiting for absolute B^iaturity if the patient be materially
incommoded for want of sight! Strict asepsis, and the use of the
irrigator for the removal of cortical remains, have rendered the
removal of immature cataracts quite a safe procedure.

The foregoing is the most common course of events in the progress

264 DISEASES OF THE EYE. [chap. x.

of a senile cataract ; but there is a less common form of it, in which
total opacity of the cortical layers never does come about. In this
form the lens is occupied by radiating linear opacities up to the very
capsule ; while between these opaque lines there are clear intervals,
which may even admit of the fundus oculi being examined, although
dimly, and which allow of a certain amount of sight. These cataracts
usually occur in myopic eyes, and they can be successfully removed.

After the stage of maturity a cataract gradually goes on to be
h/pennature. Here one of two changes takes place ; either the
cortical substance breaks down,, and becomes fluid, the nucleus
retaining its consistency, and gravitating to the lowest part of the
capsule (Morgagnian cataract) ; or, more commonly, the cortical
substance dries up, as it were, and finally comes to form, with the
nucleus, a hard flat disc. Accompanying these changes in the lens-
substance are changes in the epithelium lining the inner surface of
the anterior capsule, which result in a thickening of the capsule.
In a Morgagnian cataract the fluid cortex finally undergoes absorp-
tion, and the anterior and posterior capsules come in contact (cata-
racta membranacea). In some cases the capsule remains more or
less transparent, and the sight may greatly improve ; and cases are
on record of spontaneous cure of cataract, due to intracapsular
absorption.

The dimensions of the nucleus vary a good deal. In some
cataracts it is small, and these are called soft cataracts, as they
consist chiefly of the soft cortical substance. In others — and as a
rule in patients over sixty years of age^the nucleus is large, and
these are called hard cataracts, although they are not hard through-
out. The size of the nucleus can be estimated pretty accurately
by the extent and intensity of the yellowish or brownish reflection,
which is obtainable by focal illumination from the centre of the
cataract.

In some senile cataracts, the sclerosis is not confined to the
nucleus, but extends to the cortical layers as well. This causes
much disturbance of sight, and the term cataracta nigra is given
to these lenses, from their very dark hue, although they are not
cataracts in the true sense of the term. They require operation, and,
as they are always of large size, wide openings have to be made to
deliver them.

In the lenses of young people there is no nucleus : consequently,

CHAP. X.] THE CRYSTALLINE LENS. 265

in the complete cataracts of children and of young adults, there is
no nucleus ; the whole lens becomes opaque, and the cataract is
always soft.

Pathogenesis of Senile Cataract. — According to Priestley Smith's investi-
gations a diminished rate of growth of the lens precedes the formation of
cataract ; and it is held by some that the cataractous process in the
senile lens is the result, in the first instance, of a rapid sclerosis and shrink-
ing of the nucleus. If the process of sclerosis and shrinking be very
gradual, cataract does not appear, because the cortical layers of the lens
have time to accommodate themselves to the altered state of things ;
but, if the shrinkage be rapid, the cortical layers cannot so rapidly accom-
modate themselves, and consequently the fibrillse of these layers bscome
separated somewhat froin each other, fluid collects in the interspaces, and
causes disintegration of the lens-substance, gradually leading to opacity
of the whole lens. As the opacity increases, more fluid is present in the
lens, and this causes swelling of the lens. When the whole cortex has
become opaque, the fluid contents begin to diminish, and the lens returns
to its normal size. Senile cataract, according to this view, is entirely
a local process. But it has not been proved that the nucleus of these
cataractous lenses does undergo a process of shrinkage.

Others incline to the view, for which they advance fairly well-founded
reasons, that senile cataract is the result of certain specific toxines which
enter the lens and damage the epithelial cells lining its capsule, and that
this leads on to derangement of all the lenticular fibres.

Burdon Cooper believes that cataract is the result of a hydrolysis of
the lens protein, which results in the formation of tyrosin. Tyrosin is
not present in the normal lens but is found in the aqueous and in the
lens in senile cataract, and also in the aqueous humour after discission of
the clear lens.

Both the congenital and acquired forms of cataract are often here-
ditary.

Senile cataract has not been associated with any recognisable
disturbance of the general health, but there is some evidence to con-
nect it with a renal impermeability not sufficient to manifest itself
in appreciable clinical symptoms.

The Symptoms to which senile cataract, in the earliest stages,
gives rise are : more or less dimness of vision, as if looking through
a mist, or a net, and sometimes polyopia. The polyopia annoys
the patients especially in the evening, when they look at gas or
candle flames, the moon, etc. It is caused by the irregular astig-
matism produced by the slight changes which sometimes precede
actual opacities (p. 262), or by the points of early peripheral opa-
cities extending into the pupillary area.

266 DISEASES OF THE EYE. [chap. x.

In some cases of incipient cataract there is an increase in the
refracting power of the lens, with the result that the patient becomes
slightly myopic, if, previously, he have been emmetropic.

Oradually, as the opacity extends to other parts of the lens, the
acuteness of vision becomes decidedly affected ; and this is the
more marked, the more the cortex at the anterior and posterior poles
of the lens is involved. In those cases where the equatorial parts
of the lens are but little affected, while the polar regions are a good
deal affected, the patients see better in the dusk, or with their backs
to the light, than when their eyes are exposed to a strong light ; the
reason being that in the dusk the pupil is dilated, and light can pass
through the clearer periphery of the lens, while in a strong light the
pupil is contracted. On the other hand, when the opacity is con-
fined rather to the equator of the lens, a strong light is not disturbing
to sight ; or, if the centre of the lens be quite clear, a strong light
may even be agreeable to the patient.

According as the lens becomes more opaque, the acuteness of
vision is proportionately reduced, until, finally, even large objects
cannot be discerned, and only quantitative perception of light re-
mains. Some cataracts, however, when quite ripe, still admit of
finger-counting at a few feet.

In advanced stages of the disease, when the opacities oct-upy
a great portion of, or the entire cortex, they are easily recognised
even by ordinary daylight, often giving a greyish appearance to
the pupil.

luflaminatory exudation of some standing in the area of the pupil
would afford a somewhat similar appearance, but would be attended by
other signs of the previous inflammatory process, such as synechise, dis-
organisation of the iris, etc., and the opacity would be seen to lie more in
the plane of the iris than does any lental opacity.

The length of time occupied by the ripening of a cataract varies
in different cases from a few months to many years. In very old
persons the progress is, in general, more rapid than at an earlier
time of life. That form which commences at the equator as fine
lines is slower than that with flocculent opacities, or than that in
wdiich the cortex around the nucleus is likewise implicated at an
early period.

All examinations as to the conditions of the lens are rendered
easier and more conclusive if the pupil be previously dilated ; but

CHAP. X.] THE CRYSTALLINE LENS. 2G7

the tension of the eye should be ascertained before a mydriatic is
instilled, lest glaucoma, or a tendency to it, be present.

Treatment. — It is very doubtful whether purely medical treat-
ment is of any avail in the treatment of cataract at any stage. The
only treatment of this kind which seems to have produced slight
improvement in some cases is potassium iodide, administered in-
ternally, or applied locally by eye baths (2 to 6 per cent, solutions)
or subconjunctival injections of 1 or 2 per cent, solutions. Removal
of the cataract by operation is the only real cure for blindness
caused by it.

In cases of incipient cataract, or in those, rather, which have
advanced somewhat beyond this stage, we often find that vision
is improved, or made more pleasant, by the wearing of tinted glasses
to moderate the light. With commencing cataract, where slight
myopia has come on, low concave glasses for distant vision will, for
a time, be found of service ; while, for reading, stenopseic glasses
sometimes give good results. Yet, as a rule, patients are unwilling
to avail themselves of any of these aids.

Dilatation of the pupil is in many cases of great benefit, especially
where the nucleus is much more opaque than the cortical portion ;
but sometimes the resulting diffusion of light is distressing to the
patient, and greater impairment and confusion of vision are pro-
duced.

Patients with incipient or advancing cataract may, with impunity,
be allowed to make every use they can of the sight they possess ;
and the surgeon should give them hints as to the arrangement of
light in their rooms, and for their work, etc., so as to enable them to
employ their sight to the best advantage.

The truly distressing period in the progress of cataract, when
both eyes are affected, lies between the advent of that degree of
blindness which incapacitates the patient for reading or writing, or
for making his way about alone, and the occurrence of maturity,
or of that degree of maturity which is deemed requisite for successful
removal. This is often a lengthened time. Fortunately, in many
instances the cataract in one eye is much more advanced than that
in the other ; and then no such trial need be passed through.

The question is often asked by patients, whether the cataract in one
eye should be extracted until both eyes are blind. The answer is : —
A patient with one mature cataract, and the other progressing towards

268 DISEASES OF THE EYE. [chap. x.

maturity, should have the ripe cataract removed. Hypermaturity is thus
avoided, and also the stage of blindness above referred to. Again, if there
be a ripe cataract in one eye, and not even incipient cataract in the ether,
it is often advisable to operate for the purpose of increasing the binocular
field of vision.

Artificial Ripening. — For the purpose of hastening the maturity of
a cataract, when the patient has become incapacitated, the following
method is sometimes used. The anterior chamber is paracentesed, and,
when the aqueous humour has flowed of?, the lens is massaged with gentle
circular motions, with the angle of a strabismus hook, or other suitable
instrument, applied to the anterior surface of the cornea. The circular
massage must be applied, through the cornea, to the entire surface of
the lens as far as its very periphery. Within forty -eight hours the cortex
becomes opacjue. The proceeding acts by deranging the epithelium of the
anterior capsule, after which the aqueous humour can pass through the
intact capsule, and produce disorganisation of the lens fibres, as occurs
after the operation of discission. Care must be taken that the pressure
be not too great, or the capsule may be ruptured, or severe iritis may be
caused. This measure is employed less frequently, since it has become
the practice to extract cataract in many cases before maturity is reached.

Complete Congenital Cataract. — Children are sometimes born
with ciystalline lenses opaque in all their layers, w^hile the other
tissues of the eye are healthy. With congenital cataract defects
of the chorioid or retina, or congenital amblyopia without ophthal-
moscopic appearances, are also sometimes present, and are usually
indicated by nystagmus. These cataracts sometimes shrink, and
the remaining lens substance is contained in a flattened and much-
thickened capsule which is sometimes difficult to divide. Children
with congenital cataracts are sometimes imbecile or weak-minded.

TrcatiHcnt. — Discission.

Complete Cataract of Young People.— The spontaneous occur-
rence of total acquired cataract in the youthful lens is of rare occur-
rence, and its pathogenesis is unknown.

Treatment. — Discission.

Diabetic Cataract. — This is a complete opacity of the crystalline
lens occurring in diabetes, but the immediate cause of the cataract
is not known. The cataract does not differ in appearance or con-
sistency from other cataracts, according to tlie time of life of the
patient.

Treatment and Prognosis of Diabetic Cataract. — A few cases have
been recorded in which upon reduction of the sugar in the urine, by
suitable anti-diabetic treatment, the central opacity disappeared ;

CHAP. X.] THE CRYSTALLINE LENS. 209

but, as a rule, extraction of the cataract is the method which must
be relied on to restore sight, and, contrary to a very general opinion,
these cases are not very unfavourable for extraction operations,
except when the diabetes is rapidly progressive or there is acetonuria.
We have operated on cases of this kind, and always with success,
save once, when the eye was lost by intra-ocular haemorrhage ; and
we have seen such cases operated on successfully by others. Occa-
sionally patients operated on for diabetic cataract die of coma
within a fortnight or so after the operation, and hence, when opera-
tion is contemplated, it is necessary to submit the possibility of
this occurrence to the patient.

Glass-Blower's Cataract. — Glass-blowers are very liable to cataract.
The appearance of the cataract is characteristic ; it consists of a well-
defined disc of opacity in the centre of the posterior cortex of the lens.
It only occurs in men who have been engaged at the work for many years.
Whether this is due to the great lieat to which their eyes are exposed
to the ultra-violet rays, to profuse sweating, or to the congestion in the
blood-supply of the uvea caused by the repeated act of blowing, or to
some other cause, is unknown.

Treatment. — Extraction.

Black Cataract. — This name, as above stated, is sometimes given to
cases of extreme sclerosis of the lens, in which it assumes a dark brown
colour ; but in other cases the lens is really black. The pigment is not
a direct derivative of haemoglobin, but is the result of a cellular activity
like melanin. The prognosis for an operation in these latter cases is not
good, as they are often complicated with disease of the chorioid, or \\ith
haemorrhage in the vitreous humour.

Partial Cataracts.

These are nearly all congenital.

Central Cataract. — This is a congenital and usually non-pro-
gressive form. It is an opacity of the central, or oldest, lens-fibres,
while the peripheral layers remain clear.

Treatment. — Discission, or iridectomy.

Zonular, or Lamellar, Cataract. — This is congenital, or forms in
early infancy, and is the most common kind of cataract in children.
It usually is present in both eyes, but it has been seen in one eye
only. In zonular cataract the very centre of the lens is clear
(Fig. 99, diagrammatic), while around this is a cataractous layer
or zone, and outside that again the peripheral layers are trans-
parent. The majority of these cases are not progressive, but

270 DISEASES OF THE EYE. [chap. x.

occasionally the whole lens does become opaque, and usually then
there have been previously some sliglit opacities in the otherwise
clear cortical layers.

With oblique illumination, the cortical layers of the lens are
seen to be clear, while towards the centre of the lens
a uniform grey circular opacity will be observed. The
diameter of this opacity may be small, perhaps not more
than 3 mm. or 4 mm., or it may extend very nearly to
^ the equator of the lens. If the pupil be dilated, and

the lens examined with transmitted light, the cataractous
portion will appear as a more or less dark disc in the centre of
the lens, while all around it is seen the red light reflected from the
fundus oculi. The centre of this disc is either of the same degree
of darkness as its margin, or but very little darker ; and this fact
serves to distinguish this form of cataract from one in which the
whole centre of the lens is opaque. In the latter case it is evident
that the centre of the opacity must be darker than its margin. In
many cases small radial opacities are seen round the equator of the
lens, passing from the anterior to the posterior surface, their con-
cavity embracing the circumference of the central opacity. They
are called riders (Fig. 99).

It has been held that lamellar cataract is due to some transient
disturbance of nutrition in utero, occurring at the time the affected
layers of the lens are being laid down. But against this view is the
fact that one half of the lens only may present the appearance of
zonular cataract. The subjects of it are usually rachitic, as shown
by the irregular and imperfect development of the teeth (Fig. 100).
and by rachitic alterations in the bones
of the skull. Convulsions during infancy
in these patients are common.

The Treatment of central lental cata-
ract and of zonular cataract is similar,
and consists either in elimination of the ^ig. lOO.

lens by discission or in the formation of

a narrow coloboma downwards and inwards by means of iridec-
tomy. The latter is very decidedly to be preferred in those cases
in which the central opacity is so small that, on dilatation of the
pupil, the acuteness of vision, with the aid of a stenop^cic slit, is
increased in a satisfactory degree. When the improvement so

BP^ T?!

CHAP. X.] THE CRYSTALLINE LENS. 271

produced is but slight, the operation of discission is indicated.
The advantage of iridectomy over discission, when the former can
be adopted, is that no spectacles are afterwards required, and
that the power of accommodation is retained.

Punctate Cataract. — This is a congenital form of cataract in which
minute, rather bhiish dots are scattered through the lens. It is non-
progressive and does not affect the sight very much. It is probably a
form of zonular cataract.

Anterior Polar, or Pyramidal, Cataract may be either congenital
or acquired. In the former case it must be referred to some inflam-
matory disturbance occurring about the third period of development
of the lens. In both cases the mode of origin of the opacity is the
same, whether it be punctiform, flakelike, or pyramidal — namely,
by contact of the lens with an inflamed cornea. In foetal life this
may occur without any perforation of the cornea, as there is then no
anterior chamber. Fig 101 shows a case, in which in the left eye
a filament connects the disc-
like anterior polar cataract
with an opacity of the cor-
nea. In the right eye there
is a pyramid-shaped cataract.
After birth a perforating ulcer Fig. 101.

of the cornea is a neces-
sary precursor of this form of lental opacity, but the ulcer need
not be central (p. 65). This contact with an inflamed and ulcerating
cornea leads to subcapsular cell-proliferation, at that portion of the
capsule which is exposed in the pupillary area, and to consequent
subcapsular opacity in this small area.

No Treatment is required, as vision is not affected.

Fusiform, or Spindle-Shaped, Cataract is also congenital, and is rare.
It consists in an axial opacity extending from pole to pole, and mav be
conibined with central or lamellar opacity.

The foregoing forms of cataract, with the exception, perhaps, of the
anterior polar and genuine black cataract, are primary ; that is to say,
they are not dependent on, nor are they the results of, disease in other
parts of the eye.

Posterior Polar Cataract.— An opacity at the posterior pole of
the lens may occur congenitally.

272 DISEASES OF THE EYE. [chap. x.

Secondary, or Complicated, Cataract.

Some diseased states of tlie eye give rise to cataract.

Of this a partial kind is

Posterior Polar Cataract.— Besides the congenital variety,
posterior polar cataract may be acquired. This form is seen, with
transmitted light, as a star-shaped or rose-shaped opacity in the
most posterior layers of the posterior cortical substance, its centre
corresponding with the posterior pole of the eye.

Posterior polar cataract is usually found in eyes which are the
subjects of disseminated chorioiditis, retinitis pigmentosa or
diseased vitreous humour. It sometimes progresses, and becomes
a complete cataract ; and then the prognosis for sight after extrac-
tion is not very good, owing to the disease which is present in the
deep parts of the eye.

The additional disturbance of sight caused by the presence
of posterior polar cataract depends a good deal upon its density.

Total Secondary Cataract often ensues lipon contact of the lens
with inflammatory products in the eye — e.g. where false membranes
have been produced by inflammation in the uveal tract ; and it is
called Cataracta Accreta, when the iris or ciliary processes arfi ad-
herent to it. Cataract is also caused by detaefhment of the retina,
intra-ocular tumour, absolute glaucoma, dislocation of the lens, etc.
The reason of this is that the nutrition of the lens becomes impaired.

Such cataracts often undergo a further degeneration, and become
calcareous. Calcareous cataracts are easily recognised by their
densely white or yellowish-white appearance ; and almost always
indicate deep-seated disease in the eye, even when the functions, so
far as they can be tested, are fairly good.

These secondary cataracts rarely come within the range of
Treatment, as the diseases which give rise to them are usually
destructive of sight. When, occasionally, they can be dealt with
they should be extracted.

The term secondary cataract is also used in cases in which, after a
cataract extraction, the capsule of the crystalline lens, which is left
behind, presents an obstacle to good sight, but here it is not a
suitable term. This will be referred to again, and does not come
within the scope of this paragraph.

CHAP. X.] THE CRYSTALLINE LENS.. 273

Capsular Cataract.

By this term is meant an opacity of the anterior capsule, or of
the capsular epithelium. It is usually confined to the centre or
anterior pole, and is most frequently seen in over-ripe senile cataracts,
and in secondary cataracts.

Traumatic Cataract.

Every perforating injury of the eye which opens the capsule of
the lens is liable to cause cataract, by reason of the admission of
the aqueous humour.

Perforating injuries with sharp instruments, or the entrance of
small foreign bodies — in both cases, as a rule, through the cornea —
are the most common injuries that produce traumatic cataract.
Blows upon the eye, without any perforating wound, also, although
more rarely, produce cataract. In these latter cases there is a
rupture of the capsule, either at the equator of the lens, or on its
posterior or anterior surface.

Within a few hours after a perforating injury of the anterior
capsule, the lens-substance in the immediate neighbourhood of the
opening becomes opaque, swells, and protrudes, as a grey flufTy-
looking mass, through the opening in the capsule into the anterior
chamber, where it gradually breaks up, dissolves, and becomes
absorbed. It is immediately followed by other portions of the
lens which have become cataractous, until, after some weeks, the
whole lens will have disappeared, and the pupil will again become
black ; and the eye may now see well with a suitable convex lens.
The swelling and absorption of the lens are all the more rapid, the
larger the opening in the capsule and the younger the patient.

But the course of events just sketched is the most favourable
one, and is hardly likely to take place in a case which is wholly un-
treated. In the first place the swelling of the lens — especially if,
in consequence of a wide opening in the capsule, it be rapid — is
liable to irritate the iris, and to cause iritis ; or to push the periphery
of the iris forwards against the periphery of the cornea, block the
angle of the anterior chamber, and cause secondary glaucoma
(p. 256).

Moreover, violent plastic or purulent uveitis may come on, as the
18

274 DISEASES OF THE EYE. [chap. x.

consequence of the introduction of infective matter on the per-
foratinjj; object, or foreign body, which causes the cataract. Wliere
this occurs, the case enters the category of diseases of the uveal
tract ; and the cataract, as such, becomes a minor consideration.

Again, we sometimes meet with traumatic cataracts which do
not undergo absorption, but simply remain stationary ; or, in
the course of years, they may undergo secondary changes, similar
to those which occur in senile cataract. In these instances, the
trauma is usually a blow on the eye, not a perforating injury :
and it is believed that the rupture of the capsule closes soon after
the blow, and hence no lens matter can escape into the anterior
chamber ; also, the rupture in many of these cases is probably at
the equator of the lens, where the aqueous would not readily gain
access to the lenticular substance.

Occasionally, cataracts caused by blows on the eye (concussion
cataracts) take the form of posterior polar cataracts, very similar
to those seen sometimes w^ith chorioiditis and retinitis pigmentosa
(chap, xii.), the rest of the lens remaining transparent. These trau-
matic posterior polar cataracts sometimes clear up spontaneously.

Where the cataract is produced by a small foreign body, which
has passed through the cornea and into the lens, it is a matter of
importance, for the prognosis, to decide whether the foreign body be
in the lens, or have passed through it into the deeper parts of the
eye. In the former case we may hope to extract it with the cata-
ractous lens ; while in the latter case we must fear that it will set up
dangerous inflammatory reaction. In such cases the lens should be
well searched with focal illumination, and the transmitted light
may also be of use ; but in these traumatic cataracts there are
often glittering sectors in their deep parts, which may readily be
mistaken for a metallic foreign body. If the foreign body be of
steel or iron, the Rontgen rays may be employed for its detection
(chap. xi.).

Very rarely the capsule has been opened, and yet the lens has
not become opaque ; and, also, very rarely, after a perforating
injury, the opacity which formed has cleared away again. The
latter event is more frequently seen in cases of traumatic posterior
polar cataract than in other cases.

Treatment.— ThQ pupil should be kept dilated with atropine, in
order to draw the iris out of the way of the swelling lens matter :

CHAP. X.] THE CRYSTALLINE LENS. 275

and nothing more is necessary if complications do not arise. But
should iritis, or high tension, come on — and the surgeon must con-
stantly test the tension — it is important, without further delay, to
extract as much as possible of the cataract. This may be done
either without an iridectomy, through a linear incision some 10 mm.
long in the upper third of the cornea, or with an iridectomy, through
an incision in the upper margin of the cornea.

If a foreign body be present in the lens, extraction of the latter
with the foreign body should invariably be undertaken.

Where violent purulent or plastic uveitis is set up by the trauma,
the treatment resolves itself into that required for these inflamma-
tions (chap. vii.).

Operations for Cataract.

With regard to the State of Health of the Patient about to be oper-
ated on for senile cataract it is desirable, as in every operation, that
it should be good. Yet, we have so often in these cases to deal with
very old people, that we cannot in every instance require sound
organs and a robust constitution ; and, as a matter of experience,
serious disease of the heart, lungs, and liver, even when they all
existed in the same individual, have not proved any impediment to
a successful operation. Diabetes is no absolute contra-indication,
although, as already stated, coma does sometimes ensue, and even
in the presence of Bright's disease a successful operation may be
performed. Very advanced years, even up to one hundred, form
no obstacle.

The State of the Eye itself should be carefully investigated prior
to proposing, or undertaking, an operation for cataract, and is a
more important matter than the patient's general health. Above
all things, it is to be determined w^iether there be intra-ocular com-
plications, which would neutralise the result of a successful operation,
such as detachment of the retina, disseminated chorioiditis, atrophy
of the optic nerve, etc. The examination of the eye before the lens
has become opaque, if the surgeon have had that opportunity, will
provide the most reliable data ; and, for this reason, a careful note
should be taken of the condition of the fundus in each case of incipient
cataract. The examination of the fundus of the fellow eye, if its
lens be clear, may help in determining the point, in so far as those

270 DISEASES OF THE EYE. (chap. x.

intra-ociilar diseases are concerned which are apt to be binocular ;
but retinitis pigmentosa, which is usually binocular, is no contra-
indication to operation. Again, the ccjudition of the anterior
capsule of the lens should be observed, for a defined glistening white
square patch, about 2 mm. broad, situated in the centre of the cap-
sule, tells the tale of intra-ocular mischief. It cannot be confounded
with the more diffused striated and punctated capsular alterations
due to over-ripeness.

Finally, the functions of the eye should be examined. With
an uncomplicated cataract of the most opaque kind, good perception
of light should be present, so that the light, say, of a candle some
two metres distant may be distinguished. In less dense cataracts,
fingers may be counted at 1 m. or 1'5 m., even when full maturity
has been attained. The field of vision must be examined by means
of the ' projection ' of light — i.e. the position of a lighted candle
held in different parts of the field should be recognised by the patient,
who is required to point his finger in the direction of the light, as it is
moved rapidly from one part of the field to another. This exami-
nation is usually made by means of the light reflected from the
ophthalmoscope mirror. If the patient fail to project the light in
any direction, a diseased condition in the corresponding part of the
retina may be suspected. Yet, in cases of very old uncomplicated
cataract, the patients often project the light in some one direction,
no matter where it may come from. A certain degree of intelli-
gence on the part of the patient is required for this test.

By the foregoing means, most of the intra-ocular complications
of a serious nature can be detected ; but there is at least one against
which there is no safeguard, namely, a small circumscribed spot of
chorioido-retinal degeneration at the macula lutea (central senile
chorioiditis, p. 192). After removal of a cataract from an eye
affected in this way, the patient's vision is so much improved as to
enable him to go about alone ; but reading will still I'emain an
impossibility for him, and to that extent the result of the operation
will be a disappointment to patient and surgeon.

The Cornea should be Examined. — Such corneal opacities as
would seriously compromise vision may contra-indicate the opera-
tion ; but slighter opacities, discernible only with oblique illumina-
tion, would merely diminish the future acuteness of vision, and
would require a corresponding prognosis to be given before operation.

CHAP. X.]

THE CRYSTALLINE LENS.

277

The Condition of the Appendages of the Eye, too, must be ex-
amined. Should there be any conjunctivitis, or blepharitis, it ought
to be cured or alleviated, and a bacteriological examination should
then be made before the operation is undertaken.

In cases of dacryocystitis, extirpation of the lacrimal sac is
imperative, prior to a cataract extraction. Should the precaution
be neglected, infection of the wound with disastrous results is very
likely to ensue.

Extraction of Cataract.

Linear Extraction. — The extraction through a linear incision
in the cornea is applicable only to soft, or fluid, cataracts, in persons
under the age of twenty-five. The instruments required are : —
A spring lid speculum, a fixation forceps, a broad keratome or a
Grrefe's cataract knife, a cystotome, and a spatula. The pupil is
contracted with eserine.

The eye having been cocainised, and the speculum applied, a fold
of conjunctiva close to the lower margin of the cornea is seized (Fig.
102) with the fixation forceps, and the eye fixed by it throughout the
operation. The point of the
keratome is now entered into
the cornea above about 4 mm.
inside the margin, and is passed
into the anterior chamber. The
blade of the knife is then laid
in a plane parallel to that of the
iris, and pushed on until the
corneal incision has attained a
length of 6 or 7 mm. The point
of the knife being now laid
close to the posterior surface of
the cornea — in order that no
injury may be done to the iris
or lens when the aqueous humour

commences to flow off — the instrument is very slowly withdrawn,
so that the aqueous humour may come away gradually, w^ithout
causing prolapse of the iris. In withdrawing the knife it is well to
enlarge the inner aspect of one or other end of the wound, by a
suitable motion of the instrument in that direction.

;^S^=

Fig. 102.

278

DISEASES OF THE EYE.

[chap. X.

The keratome being now laid aside, the cystotome is passed into
tlie anterior chamber (Fig. 103) as far as the opposite pupillary
margin, care being taken, by keeping the sharp point of the instru-
ment directed either up or down, not to entangle it in the wound

or in the iris. The point is now
turned directly on to the anterior
capsule, and, by withdrawing the
z::^z=z^zi. cystotome towards the corneal
incision, an opening in the cap-
sule of the width of the pupil is
produced. The cystotome is then
i-emoved from the anterior cham-
ber, with the same precautions as
^ on its introduction.

The spatula is then placed on
the outer lip of the wound, and
the latter is made to gape some-
what, gentle pressure being at the
same time applied to the inner
of the eye by the fixation forceps, and in this way the
evacuated. When the pupil has become quite black the

Fig. 103.

aspect
lens is

operation is concluded. If pressure do not at first clear the. pupil
completely, the speculum should be removed, the eyelids closed,
a compress applied, and a few minutes allowed to elapse, in
order that some aqueous humour may be secreted. A renewal
of the efforts to clear the pupil will probably now be successful,
or, if not, another pause may be made, and then fresh attempts em-
ployed until the pupil is quite clear. Fragments may be fetched
out of the anterior chamber with the spatula, or better still they may
be washed out of it with an irrigator. Should some fragments be
left, no ill results need necessarily follow, although iritis is more apt
to supervene than if the lens be thoroughly evacuated. Fragments
left behind become absorbed. If there be a prolapse of the iris
which cannot be reposed, it must be abscised.

The Combined Operation {i.e. combined with an iridectomy).
For success in the cataract operation, it is necessary, not only to
select a rational method, but also to devote the utmost attention
to a series of minute details in its performance. We shall describe
the operation as we are in the habit of performing it.

THE CRYSTALLINE LENS. 279

Preparation of the Patient. — A gentle purgative is given the day
before tlie operation, so that the bowels need not be disturbed for
two days after the operation. The face is washed with hot water
and soap, shortly before the operation.

Preparation of the Eye. — Just before the operation, at intervals
of two minutes, three drops of a sterilised solution of adrenaline
(1 in 1000) containing 3 per cent, of cocaine are dropped into the
eye. Finally, the lids having been everted, the conjunctival sac is
thoroughly washed out by irrigation with sterilised physiological
solution of common salt, particular attention being paid to the
fornix of each lid, and to the inner and outer canthus. Then the
skin of the eyelids and immediate surroundings of the eye are
painted with tincture of iodine and the eyelashes are cut short so
as to obviate contact with the knife. If the iodine be not used
a piece of moistened sterilising gauze should be placed over the
patient's face, leaving an opening for the eye.

Preparation of the Instruments. — Immediately before the opera-
tion the instruments are sterilised by boiling and are then plunged
for a moment into absolute alcohol, laid on a sterilised porcelain
tray, and covered with a sterilised cloth, until required. It is better
to have the instruments dry when in use.

During the Progress of the Operation, small pledgets of sterilised
lint, wet with the sterilised salt solution, are employed to wipe
away coagula, cortical masses, etc., and are not used a second time.
An assistant should place the instruments in the surgeon's hand in
their turn, and take out of his hand those he has used, in such a
manner as to render it unnecessary for the operator to look away,
even for a moment, from the field of operation.

The Operation. — A spring wire lid-speculum is applied. The
eye is fixed with a catch fixation forceps by a fold of conjunctiva and
sub- conjunctival tissue, below the vertical meridian of the cornea, or
a little to one side of this line (Fig. 104).

The point of the knife is entered just outside the margin of the
clear cornea, at the outer extremity of an imaginary horizontal line
which would leave a third of the corneal circumference above it.
The knife is then passed cautiously through the anterior chamber,
and the counter-puncture is made just beyond the corneal margin
at the inner extremity of the horizontal line described (Fig. 104),
and the incision is then finished in the sclero-corneal margin by a few

280 DISEASES OF THE EYE. [chap. x.

slow to-aiid-fro motions of the knife. The blade will then be found
to be under the conjunctiva, of which a flap is formed in cutting out.
We consider it a great mistake to make a smaller incision, or to try
to vary the size of the incision according to the presumed size of the
cataract. Within limits, a large incision heals as well as a smaller
one, and it avoids the necessity for using any undue pressure in the
delivery of the lens. While the incision is being made, the aqueous
humour flow^s off.

The Second Stage of the Operation consists in an Iridectomy.
The fixation of the eye having been given over to the assistant, the
iridectomy is performed by passing a curved iris forceps into the
anterior chamber, seizing the smallest possible portion of the sphincter
of the iris at a point corresponding with the centre of the incision,
drawing it out, and with the forceps-scissors excising a very small
central bit of iris. This should be done by approaching the forceps-
scissors from over the cornea — i.e. at right angles to the wound —
the iridectomy being tkus made with one snip of the instrument,
and, if care be taken to keep the blades close to the forceps, a narrow,
neat coloboma will be obtained. A Tyrrell's hook, instead of a
forceps, may be used to draw out the iris, and this stage of the
operation is thereby rendered less painful, as the pinching of the
iris with the forceps causes pain. A small coloboma, say of 2,mm.
to 3 mm. in width, as in Fig. 81, is sufficient to allow of an easy
delivery of the lens by doing away with the resistance of the sphincter
iridis, and to prevent secondary prolapse of the iris {vide infra) ;
and its advantages over a wide iridectomy, from an aesthetic point
of view, are obvious. It should be the object of the surgeon to
obtain the smallest possible coloboma. The procuring of a neat
coloboma is much facilitated if, prior to the operation, the pupil has
been contracted (Fig. 104) by the instillation of one or two drops of
solution of sulphate of eserine. We now always made a peripheral
iridectomy, leaving the sphincter intact (see Glaucoma, p. 255). If
this be done the delivery of the lens must precede the iridectomy
and eserine should not be put in before the operation.

The Third Stage of the Operation is the Capsulotomy. The
operator takes the fixation forceps from his assistant, who then
raises the speculum and eyelids slightly off the globe, in order that
no pressure may be exerted on the latter during the remainder of the
operation. The surgeon, passing the cystotome into the anterior

CHAP. X.]

THE CRYSTALLINE LENS.

281

chamber, divides the anterior capsule of the lens by two incisions,
one passing from the lower pupillary margin upwards and outwards,
the other upwards and inwards, as far as the anterior surface of the
lens can be seen, while
a third incision is made
along the upper peri-
phery of the lens. An
extensive opening in
the capsule is of im-
portance, because other-
wise difficulty in de-
livery of the lens may
be experienced, and be-
cause a small opening
renders the occurrence
of secondary cataract
more likely. In divid-
ing the capsule it is
important not to dig
into the lens, as this,
in the case of a hard
cataract, is apt to dislocate it. A rather oblique application of the
cystotome to the capsule is, for this reason, the best.

The cystotome as it is withdrawn may pull a tag of the capsule
into the corneal wound, where it lies until the end of the operation,
and where, owing to its transparency, it may easily pass unnoticed.
Such a tag acts as a foreign body, and may subsequently form the
starting-point of troublesome complications.

Capsule forceps have been devised for the purpose of taking away
a large portion of the anterior capsule, instead of merely dividing
it ; but this does not altogether obviate the danger of capsule in the
wound, nor does it do away with the likelihood of secondary cataract.
The method has no advantages over that just described, in cases
where the capsule is not thickened. But, when the anterior capsule
is thickened, and is therefore almost certain to cause an obstruction
to vision, it is always desirable to tear away a central portion of it
with forceps.

The Fourth Stage is the Delivery of the Cataract. The eye is
drawn gently downwards— the patient being called on to assist in

Fig. 104. — Cataract extraction. Position
of the knife after the counter-puncture has
been made. Lower dotted hne indicates
where the sclero-corneal incision will be, and
the upper dotted line shows the limit of the
conjunctival flap.

282 DISEASES OF THE EYE. [chap. x.

this motion by looking towards his feet ; the spoon or spatula is
placed just below the lower edge of the cornea, and gentle pressure
is exercised on this place, the pressure being gradually increased,
until the upper margin of the lens presents itself in the wound, when,
the same pressure being maintained, the spoon is advanced over
the cornea towards the wound, pushing the lens before it and out
through the wound. When the greatest diameter of the lens has
passed the wound, the pressure of the spatula should immediately
be diminished, lest rupture of the zonula be caused. The fixation
forceps and speculum are now removed from the eye, and a cold
sterilised compress is laid on the closed lids.

It may be noted that the fixation forceps and the speculum are
used until this late stage in the operation. Some operators employ
neither fixation forceps nor speculum from beginning to end of
the operation ; while others discard the fixation forceps when the
corneal section is completed, but retain the speculum until after the
iridectomy only, delivering the lens with the finger placed on the
lower lid. The use of the fixation forceps and speculum until after
the lens is delivered gives more security and stability to the operator,
but if escape of vitreous be feared, the speculum should be removed
before the lens is delivered.

The Fifth Stage consists in Freeing the Pupil of any Cortical
Masses which may have been rubbed off in the passage of the lens
through the wound, and is what is called the Toilette of the Wound.
The presence of cortical remains is recognised by the pupil not
having become quite black, or by the vision not being such as it
ought to be (fingers counted at several feet), or by inspection of the
cataract just removed showing that some portions of it are left
behind. The use also of focal electric illumination for the detection
of cortical fragments is very advantageous. If any fragments be
present, the cold sterilised compress having lain on the eye for a few
minutes to enable some aqueous humour to collect, the operator,
facing the patient, raises the upper lid with the thumb of the left
hand, and then, with the first and second fingers of the right hand
laid on the lower lid, he makes light rotatory motions with this lid
over the cornea so as to collect the masses towards the pupi), and
then with a few rapid light motions upwards, with the margin of the
lid, these masses are driven towards, and out of, the w^ound. Care
and delicacy of touch are required in order to perform this lid-

CHAP. X.] THE CRYSTALLINE LENS. 283

mancBuvre successfully, without rupturing the hyaloid by undue
pressure.

Of late we always remove cortical masses with the irrigator, which
leaves a beautifully clear pupil and cleans the field of operation
admirably.

With an iris forceps the blood-clots which may adhere to the
wound are now removed.

The coloboma has now to be seen to. The peripheral portions
of the iris corresponding with the ends of the wound are apt to have
become prolapsed in the course of the operation, and to have dis-
placed the angles of the coloboma upwards. If this be not corrected,
the prolapsed portions of the iris heal in the wound, and cause
bulgings there later on, the pupil in the course of some months
becoming drawn up towards the cicatrix. Hence, in every case,
even where everything seems to be in order, it is important to pass
the narrow spatula into the anterior chamber, and gently to stroke
down each pillar of the coloboma as far as it can be brought. The
instillation of eserine, before the commencement of the operation,
will cause the sphincter iridis to assist in producing the desired
result. Finally, the conjunctival flap is spread out smoothly into
its place, so that it covers the incision in the corneo-scleral wound.
All this is aptly termed the toilette of the wound.

The sight of the eye should then be tested by finger counting,
as this affords the patient satisfaction, and lends him courage for the
next few days of strict quiet. Patients, especially those for whom
cataracts with yellowish or orange-coloured nucleus have been
extracted, often state now that all objects seem to them to be of a
deep blue colour. This is a contrast effect, due to the elimination
of the yellow medium through which light had reached the retina.
A drop of eserine solution is instilled, to provide further security
against prolapse of iris. Finally, the conjunctival sac is flooded
with the sterilised saline solution.

The dressing is now applied. A piece of dry sterilised lint,
sufficiently large to extend J inch beyond the orbital margin in
every direction, is laid on the closed eyelids. Pieces of sterilised
absorbent cotton-wool are laid on this, the hollows at the inner
canthus, etc., being carefully filled up ; so that, when the bandage
is applied, it may exert equal and gentle pressure on every part of
the eye. Three turns of a narrow roller bandage over the dressing

284 DISEASES OF THE EYE. [chap. x.

and round the head are applied ; but various other, and doubtless
equally good, forms of bandage are in use. The pressure of the
bandage need only be sufficient to maintain the dressing firmly in
its place. The othei eye is closed by a light bandage.

A few surgeons think it safer to perform a preliminary iridectomy
some days or weeks before extracting the lens, but in addition to the dis-
adv'antage of submitting the patient to two operations instead of one,
it renders difficult the subsequent making of a conjunctival flap, and is
liable to cause adhesion of the pillars of the iris in the angle of the wound.

Accidents liable to occur during the Operation. — The Incision may be
made Too Short, and the delivery of the lens, consequently, may be so
difficult that the margins of the wound become contused, and consequently
suppuration may be promoted. The zonula, too, may be ruptured by
the excessive pressure used to force the lens out through the narrow
aperture, and prolapse of the vitreous may ensue. If the directions above
given be carefully attended to, the vast majority of both hard and soft
cataracts may be extracted without difficulty ; but should the wound be
made too small, it can best be enlarged by the forceps-scissors, or a blunt-
pointed knife made for the purpose.

The iris may come forward in front of the knife edge when making
the incision. In such a case it may be made to recede by drawing the
eyeball forwards with the knife ; if the aqueous have escaped, the knife
may be withdrawn and a spatula inserted with which the iris can be pro-
tected, while the knife is reintroduced for the completion of the section.

Haemorrhage into the Anterior Chamber may take place. It may be
from the iris, from the corneo -sclerotic margin, or from the conjunctiva.
The blood can be best removed with the irrigator, or if it be not available
pressure with the spatula on the cornea, which causes the wound to gape,
is often successful in clearing the chamber of blood, which might interfere
with accurate division of the capsule. Yet, when this cannot be com-
pletely got rid of, the capsulotomy can be performed by the exercise of
greater care. Adrenaline dropped into the eye aids in arresting the
bleeding.

Prolapse of the Vitreoife Humour. This accident may be caused by
undue pressure made on the eyeball by the speculum, fixation forceps,
or spatula, or by the lower lid during the lid-manoeuvre. It may be due
to defective zonula with fluid vitreous humour. In other cases it may be
caused by the patient, who " squeezes " the eye by contraction of the
orbicularis. The best way to deal with " sc[ueezers," short of using an
anaesthetic, is to remove the speculum, and get an assistant to put firm
pressure on the eyebrow with the fingers of one hand, which at the same
time draws the upper eyelid well up, while the lower eyelid is drawn apart
with the thumb of the other hand. When the vitreous prolapses prior
to delivery of the lens, the latter falls back into the eye, and can orly be
delivered by at once drawing it out with a vectis ; and the accident is
one of the most serious which can occur in tlio course of the operation,
for it is often impossible to reach the lens witli the \ectii; without doing such

CHAP. X.] THE CRYSTALLINE LENS. 285

damage to the eye that sight is lost. Loss of vitreous after deUvery of
the lens is less serious ; indeed, a considerable portion of the vitreous may
then escape without ill result to the eye ; yet it increases the traumatism,
and renders inflammatory reaction more liable to occur. Opacities in the
posterior chamber of the eye are frequently an ultimate rcvsult of loss of
vitreous ; but a much more serious consequence is sometimes seen in
detachment of the retina.

Collapse of the Cornea. In some cases, especially in old people, the
cornea, instead of retaining its curvature, falls into folds, and lies, more or
less flattened, on the iris. This is not of any consequence, as the cornea
becomes restored to its usual shape when the anterior chamber is formed.

Normal After -Progress. — Soon after the completion of a normal
operation, the effect of the cocaine having passed off, some smarting
commences, and continues for four or five hours. After that time,
the patient has no unpleasant sensation in the eye, unless it be some
itching, or a slight momentary pain, or sensation of a foreign body,
especially when the eye is moved under the bandage. The first
dressing is made in forty-eight hours, in a manner similar to that
immediately after the operation, a drop of atropine being instilled,
as also at each successive dressing ; and the sterilised salt solution
is used for freely w^ashing the margins of the eyelids, some of it
being allowed to trickle into the conjunctival sac. At this first
dressing, it is w^ell to abstain from a very minute or lengthened
examination of the eye ; but, if the lid be gently raised, the w^ound
will be found closed, the cornea clear, the anterior chamber com-
pletely restored, and the pupil semi-dilated and black. The sub-
sequent dressings are made night and morning, for the purpose of
instilling atropine. On the third day after the operation the patient
may be allowed to sit up, the room being kept moderately dark ;
and on the fifth or sixth day the bandage may be left aside perman-
ently, and dark glasses w^orn in its stead. In the course of a few
more days the patient, having been gradually accustomed to more
light, may be allowed out of doors. It is desirable to continue the
use of atropine for about a fortnight longer, or until all abnormal
vascular injection of the white of the eye has disappeared, as until
then there is danger of iritis. (For selection of glasses in aphakia
see end of this chapter.)

Irregularities in the Process of Healing. — The pain may continue longer
than four or five hours, and it is then well to give a hypodermic injection
of morphia in the corresponding temple, so that the patient may not be

286 DISEASES OF THE EYE. [chap. x.

restless. Should severe pain come on some hours later, it is apt to be due
to an accumulation of tears under the eyelids, and it immediately subsides
on the bandage being removed, and exit given to the tears by slightly
opening the eye.

Post-operative Conjunctivitis. — Conjunctivitis in varying degrees of
severity is liable to occur at times. The very fact of bandaging the eye
tends to favour the development of any organisms present in the con-
junctiv^al sac, by diminishing the cleansing lid movements and the secre-
tion of tears, as well as by increasing the temperature. The use of too
strong antiseptics also promotes its development, or lens matter, blood-
clots, etc., left lying in the conjunctival sac.

Late Appearance of the Anterior Chamber. — At the first dressing it
will sometimes be found that there is no anterior chamber, although the
appearance of the wound is satisfactory ; but this need occasion no alarm,
as the anterior chamber is sometimes not restored for three or foiu- days.
Should the anterior chamber be slow in forming, it is only necessary to
remove the bandage and substitute a wire mask or shield, when closure
of the wound usually takes place. But in some of these cases a down-
growth of corneal epithelium may take jjlace, w'hich may spread over the
whole of tlie iris and anterior chamber and may cause glaucoma.

Striped Keratitis. At the first dressing, also, it may sometimes be
observed that there is a more or less well-marked striated cloudiness of
the cornea, extending over nearly the whole of it, or occupying only a
part in the immediate neighbourhood of the wound. This opacity is
held by some to be the result of injury to the endothelium of the posterior
surface of the cornea during the operation. It is this endothelium which
protects the cornea from being infiltrated by the aqueous humour, and the
appearance we call striped keratitis is caused by oedema of the colrnea.
According to another explanation, striped keratitis is due to folding of
the posterior layers of the cornea, on account of the difference in tension
in the vertical and horizontal directions. Striped keratitis is, for the
most part, of no serious import, as it usually passes away in a few days,
and leaves the cornea perfectly clear.

Expulsive Haemorrhage. Soon after the operation — it may be before
the patient is removed from the couch — great pain sets in. On removal
of the dressings they are found to be saturated with blood, while the
corneal flap is turned downwards, the wound is gaping, and througli it
blood-clot, vitreous, and iris protrude. The haemorrhage is from the
retinal or cliorioidal blood-vessels which are atheromatous. The accident,
which is rare, cannot be foreseen, and the eye is always lost.

Septic Infection. With careful aseptic measiu-es this is a rare event.
Wlien it occurs, it usually does so between the twelfth and thirty-sixth
hour after the operation, rarely earlier or later, and is very serious ; for,
in the vast majority of cases, do the surgeon what he may, it leads to the
loss of the eye. Its onset is usually made known by severe pain of a con-
tinuous aching kind in and about the eye ; and it is thus easily distin-
guished 'from tlie slight, short, stabbing pain, with long intermissions,
and gradually diminishing intensity, which some patients complain of,
and whicli lias no evil import. On removing the bandage the margin of

THE CRYSTALLINE LENS. 287

the upper lid will be found oedematous, the eye full of tears, and the wound
covered with a layer of muco-pus, which can be removed with the forceps
in one mass, while the aqueous humour and cornea may already present
some opacity. In some hours more, the corneal opacity increases con-
siderably, the iris becomes distinctly inflamed, and the pupil filled with
a mass of inflammatory exudation. In many instances the
attack commences as septic iritis. The inflammatory process
may remain confined to the wound and iris, and when, in
the course of some weeks, it entirely subsides, it leaves the
pupil drawn up towards the wound so that an appearance
as in Fig. 105 is presented. Or, the inflammation may strike
into the ciliary body and chorioid, and produce purulent panophthalmitis
with total destruction of the eye.

The pneumococcus is the most frequent cause of septic inflammation,
but staphylococci and streptococci are sometimes responsible for it. Owing
to the vascularity of the conjunctiva, sepsis is less liable to occur with a
conjunctival flap than with a purely corneal incision.

To combat Septic Infection the best method is the immediate cauterisa-
tion of the corneal wound, if it be the seat of the process, in its whole
extent, with the galvano-cauter5^ Also, the wound may be opened up
from end to jend with a spatula, the aqueous humour evacuated, and the
anterior chamber washed out with injections of sublimate solution 1 in
10,000, while the conjunctival sac is irrigated with the same solution.
If necessary these measures are to be repeated at intervals of eight or ten
hours. Good results have been obtained from use of the staphylococcus
vaccine. Sub-conjunctival injections of solution of sublimate 1 in 2,000,
or of oxycyanide of mercury 1 in 5,000, are often of use in these cases, if
they be commenced very soon after the onset of the attack. Half a c.cm.
is to be injected as far back as possible under the conjunctiva once, or
even twice, in twentj-four hours ; and from four to eight injections are
usually needed according to the severity of the case. Intense chemosis
and much pain are caused. To prevent the painfulness of the injection,
five drops of a 1 per cent, solution of acoine may be added to the quantity
cf oxycyanide of mercury solution injected, or to the sublimate injection
a few drops of 2 per cent, cocaine solution. Nevertheless very severe
radiating pain usually comes on a quarter of an hour later, and continues
for several hoiu-s. Hot fomentations afford some relief from this pain.
The patient should be confined to bed, and a dressing should be applied
to the eye.

Plastic Iritis. A few days after the operation plastic iritis, sometimes
of a severe type, may come on. It, too, must be reckoned as due to
infection during the operation, especially if some lens-substance have
remained, for the latter is a favourable nidus for the cultivation of infective
material. The iritis is ushered in with the usual symptoms of pain.
General plastic uveitis may ensue, and sympathetic uveitis may result.
It is said that a mild iritis may be caused by the staphylococcus albus.
Treatment consists in strict confinement to a dark room, with atropine,
and sub-conjunctival mercurial injections, and quinine or large doses of
salicylate of soda internally.

.288 DISEASES OF THE EYE. [chap. x.

Detachment of the Chorioid. Fuchs has pointed out that detachment
of the chorioid occurs some days after cataract extraction, in some of
those cases in which the anterior chamber does not form ; or in which,
having formed, it becomes empty again. Detachment of the chorioid
occurs occasionally after iridectomy unconnected with cataract extraction.
It can be seen with the ophthalmoscope, and sometimes even with focal
illumination. Vision while the lesion is at its height is seriously affected,
but the prognosis is good, for the detached portion always becomes reposed.
Cystoid Cicatrix. After convalescence, the cicatrix in the corneal
margin sometimes becomes prominent and semi-transparent, presenting
the appearance of a vesicle, and may attain a large size. The extremities
of the incision are the most common positions for this condition, but it
may occupy the entire length of the cicatrix. It does not generally appear
for some weeks, or more, after the operation. In some cases it is caused
by a tag of iris which is incarcerated in the wound ; but in other cases by
a small piece of capsule, which has similarly healed in the wound. Irregu-
larity in curvature of the cornea, and consequent irregular astigmatism,
are the least of its evil consequences. If the condition be caused by in-
carceration of iris, the pupil will be gradually drawn close to the upper
corneo-sclerotic margin ; while, if it be caused by a portion of capsule,
irido-cyclitis may be produced. Whether the iris or the capsule be the
cause, these eyes are always exposed to the danger of a sudden onset of
purulent irido-chorioiditis (p. 192). All this demonstrates the immense
importance of attention to those details of the operation, which are calcu-
lated to obviate incarceration of iris, or of capsule, in the cicatrix.

Cataract Extraction without Iridectomy, or, as it is more com-
monly termed, The Simple Operation.— This method differs from
the Combined Operation, in that the incision occupies a greater
extent (about one-third) of the circumference of the cornea, and
that no iridectomy is made. The round pupil, and consequent
prettier appearance of the eye, and the diminished tendency to loss
of vitreous, and to incarceration of the capsule, are the advantages
this procedure has over the Combined Operation as above described ;
for vision with a circular pupil is not appreciably better than where
a narrow coloboma has been made.

On the other hand, the extraction without iridectomy exposes
the eye to the serious danger of prolapse of the iris into the wound
some hours, or days, after the operation. An iridectomy must be
made in all cases in which the iris cannot be satisfactorily reposed
after delivery of the lens. These cases are, however, few in number.
But, even when the iris can be well reposed, security against the
occurrence of a prolapse within the first two or three days after the
operation is not obtained ; nor does eserine, nor anv other means,

X.] THE CRYSTALLINE LENS. 280

provide the desired safeguard. Prolapse of the iris does take place
after a number of these operations, and there is no means of fore-
telling in what eyes it will occur. The prolapsed j^ortion of iris
heals in the wound, which then, in a few weeks, becomes more or
less cystoid and bulging, causing displacement of the pupil and
irregular curvature of the cornea, with resulting deterioration of
vision. Nor is this all ; for such eyes are liable — weeks, months,
or even years after the operation — to take on severe irido-cyclitis,
ending in total loss of sight. Another disadvantage of the operation
is that removal of cortical remains cannot be so effectually per-
formed as where a coloboma has been made.

Why it is that in the simple extraction prolapse of the iris with
subsequent incarceration is more liable to occur, even some days
after the operation, than in the combined operation, and why it is
difficult to devise a sure means for preventing the accident, as, also,
how even a very narrow coloboma is almost ahvays sufficient to
protect the eye from this accident, can be explained as follows : —
Within a few hours after the operation the wound in the corneal
margin commonly closes, the aqueous humour collects, and the
anterior chamber is restored. But it takes many hours more for the
delicate union of the lips of the wound to become quite consolidated,
and during this time it requires but a slight thing — a cough, a sneeze,
a motion of the head, the necessary efforts in the use of a urinal or
bed-pan, no matter how careful the nursing — to rupture the newdy
formed union ; and, as a matter of fact, this often does take place.
The aqueous humour then flows away through the wound with a
sudden gush, and, where the simple extraction has been employed,
carries with it the iris. It is the aqueous humour behind the iris
which is chiefly concerned in the iris-prolapse.

The formation of even a narrow coloboma prevents prolapse of
the iris when the wound is ruptured, but this is not because the
portion of iris which is liable to prolapse has been taken away,
for that would be nothing less than the whole of that part of the
iris which corresponds with the length of the wound. The coloboma
averts secondary iris-prolapse, by providing a way for the aqueous
humour contained in the posterior part of the anterior chamber to
escape directly through the w^ound, without carrying with it the
iris in its rush ; and the narrowest coloboma which can be formed
is sufficient for the purpose.
19

290 DISEASES OF THE EYE. L^hap. ^.

But all the advantages of the simple operatiou, without the
danger of prolapse, can be obtained by making a small peripheral
iridectomy or simple incision of the iris, which leaves the sphincter
intact. When this procedure is adopted, the lens is delivered before
the iridectomy is made.

Extraction in the Capsule. — The ideal cataract extraction is
that in which the opaque lens in its capsule is removed, thereby
obviating all subsequent troubles due to the capsule. The objection
which has prevented the method from coming into general use is
the great danger of prolapse of vitreous which must attend it, owing
to the liability of the hyaloid membrane to be ruptured during
delivery of the cataract. The operation has been performed by
ophthalmic surgeons from time to time, and has been more especially
cultivated in India by Major Henry Smith. His incision lies in the
cornea about 3 mm. below its upper margin, the puncture and
counter-puncture being in the corneo-scleral margin, as peripherally
as possible. The speculum is then removed, and the assistant raises
the upper lid w^ith a strabismus hook, at the same time drawing the
eyebrow and upper lid upwards, with firm pressure of the fingers,
while the lower lid is drawn down with the other hand. The curve
of a strabismus hook is placed on the cornea in its lower third, and a
Daviel's spoon just above the upper edge of the wound. With these
instruments gentle pressure and counter-pressure are made, until
the lens is more than half delivered ; it is then tilted with the hook,
and the delivery is completed. The operation may be done with or
without iridectomy, but must be performed slowly and cautiously,
else the lens capsule may be ruptured, and the object of the method
frustrated. Major Smith, in a large number of cases, had loss of
vitreous in only 6*6 per cent. This method is still on its trial in
Europe and has not met with universal approval.

Mental Derangements after Cataract Extractions. — After cataract ex-
tractions, during the period of confinement to bed, passing mental dis-
turbance is sometimes seen in old people. This usually takes the form
of confusion of ideas, hallucinations, and terror. It is hard to assign a
cause for it, but probably it is mainly due to the quiet, and to the exclusion
of light if a binocular bandage have been applied, following on a period
of some anxiety and excitement. A few doses of sulphonal, and permis-
sion to sit up — at least in bed — with removal of the bandage from the
unoperated eye, will be the best measures to adopt in such a case ; and
speedy restoration of mental equilibrium may be looked for with confidence.

CHAP. X.] THE CRYSTALLINE LENS. 291

Care should be taken not to mistake the symptoms of atropine poisoning
for this form of mental disturbance.

Secondary Glaucoma after Cataract Extraction occurs now and then, by-
whatever method the extraction may have been performed. This, per-
haps, is contrary to what would be expected, in view of the diminished
contents of the globe, and especially where an iridectomy has been made.
High tension in these instances may come on soon after recovery from
the cataract operation, or after a good result has existed for a consider-
able time. It is due in some cases to the corneal epithelium growing into
the wound and into the anterior chamber, where it spreads over the angle
of the latter, and occludes the ways of exit. It is associated then with
slow formation of the anterior chamber (see above). Glaucoma may also
arise from blocking of the angle of the anterior chamber by accumulations
of cells in cases of extraction followed by iritis with punctate deposits.
Or again there may be adhesion of the capsule or hyaloid membrane to
the w^ou^nd. In the latter case division of the capsule along the inner
surface of the wound is indicated, otherwise trephining or iridectomy
should be done.

Erythropsia after Cataract Operations. For an account of this see
chap. xiv.

Secondary Cataract. — The term secondary cataract, as here
employed (compare p. 272), usually means a closure of the opening
which is present in the anterior capsule after the removal of a cata-
ractous lens, combined with a thickening of the capsule in some
cases, whereby an impediment is offered to the rays of light in
passing through the pupil. The thickening may have pre-existed
in the capsule, or it may be due to subsequent proliferation of the
epithelial cells on the inner surface of the capsule. Or, without
becoming thickened, the capsule may become wrinkled, and cause
irregular refraction of the rays entering the eye and consequent
lowering of the vision. The term is also applied to those cases in
which, after cataract extraction, an exudation in the pupil, following
upon iritis, has occurred. Finally, and very incorrectly, it is applied
to the cases which Fig. 105 represents, in which, after suppuration
of the wound with irido-cyclitis, the iris is dragged upwards, and the
pupil is consequently obliterated.

The most simple form of secondary cataract occurs as a very fine
cobweb-like membrane — the capsule of the lens — extending over
the whole area of the pupil, which can often only be discovered by
careful examination with oblique illumination. It may not cause
any trouble of vision until some months after the extraction, when
a little thickening or wrinkling of it may have taken place.

lotomy, as the operation for making a clear opening in

202 DISEASES OF THE EYE. [chap. x.

this membrane is called, is performed with a Knapp's needle-knife.
This instrument has a blade 4J mm. in length. It cuts on one side
only, and the blade and the evenly rounded shaft are so proportioned
that the shaft fills exactly the opening made by the blade, and con-
sequently the needle can be moved within the anterior chamber
in every direction, without escape of aqueous or bruising of the
cornea. Tlie instrument must be of the utmost sharpness in point
and edge, so that it may cut, and not tear. The point of the needle-
knife is entered subconjunctivally into the anterior chamber, and
made to pierce the capsule, and with one sweeping motion of the
blade an opening is cut in it, hard and inelastic bands being avoided.
Ziegler's knife is also a useful instrument, and for tough membranes
a better one. With it a sawing motion is used.

Iridotomy is the operation used for cases (as in Fig. 105) where
the iris forms a complete ^nd tightly stretched curtain across the
pupil. A vertical incision having been made in the cornea, about
3 mm. long, and the same distance removed from its inner margin,
the closed blades — one of which has a sharp point — of de Wecker's
forceps-scissors are passed into the anterior chamber. The blades
are then opened, and the sharp point of one of them is forced through
the stretched iris, and some 3 or 4 mm. behind it. By closing the
blades the tightened iris fibres are cut across, and on their retraction
a central clear pupil is formed in the iris and retro-iridic tissue.

Another method consists in making two oblique incisions in the
iris with the scissors from either angle of the wound, these incisions
meet below, thus isolating a Y-shaped portion of iris which can be
grasped with a forceps and excised at its base above. With the object
of preventing loss of vitreous, Elsching does a similar operation, but
introduces the scissors through two small incisions made by trans-
fixion of the cornea with a cataract knife.

Ziegler's Operation is performed with his knife, which has a
straight, narrow blade 7 mm. long, the shank just fitting the puncture
that is made. It is introduced at the upper margin of the cornea,
carried to a point 3 mm. from the opposite periphery of the iris, and
3 mm. from the lower end of the vertical meridian. The membrane
is then pierced and cut upwards, with a very slight sawing motion.
The point of the blade is then carried an equal distance to the
other side of the vertical meridian, the membrane again pierced
and cut upwards to the termination of the first incision. The flap

CHAP. X.]

THE CRYSTALLINE LENS,

293

of iridic tissue tlins formed retracts downwards, leaving a wide
triangular pupil.

Discission means the tearing of the antei'ior capsule of the
lens with a needle, so as to give the aqueous humour access to the
lenticular fibres, which causes them to swell, and gradually to
become disintegrated and absorbed. The larger the capsular open-
ing, the more freely is the aqueous brought in contact with the
lens, and the more rapid is its swelling. The rapidity of the swelling,
disintegration, and absorption depend, also, on the original con-
sistence of the lens. The softer it is the more rapid is the process,
the completion of which may require from a few weeks to many
months. It is wise to make the first discission of moderate extent,
especially in adults.

The instruments required are a spring speculum, a fixation
forceps, and a discission needle. The pupil is to be dilated with
atropine.

The eye having been cocainised, the speculum applied, and the
eye fixed close to the inner margin of the cornea, the needle is passed
under the conjunctiva a few millimetres outside the margin of the
cornea, and enters the anterior chamber sub-conjunctivally at the
sclero-corneal margin. It is then advanced upwards to the upper
margin of the pupil (Fig. 106),
where it is passed into the
capsule, but not deeply into
the lens, and a vertical incision
is effected by withdrawing the
instrument slightly. If an ex-
tensive opening in the capsule
be wished for, a horizontal
incision can be added to the
vertical one by a corresponding
motion of the needle. During
these manoeuvres the sclero-
cornea, at the point of punc-
ture, must form the fulcrum

for thejnotions of the instrument. The instrument is then with-
drawn from the eye, and some aqueous humour escapes through
the opening. Atropine is instilled, and the dressing applied.
The patient is kept in bed for a day, and then the dressing may be

294 DISEASES OF THE EYE. [chap. x.

dispensed with, and dark spectacles worn. The iris is to be kept
well under the influence of atropine, until the absorption of the lens
is completed. Repetition of the operation is called for, if the opening
be so small as to admit of but a very slow absorption of the lens, or
if, as sometimes happens, the opening should close.

This method is applicable to all complete cataracts up to the
twenty-fifth year of age, and to those lamellar cataracts up to the
same age in which the opacity approaches so close to the periphery
of the lens, that nothing can be gained by an iridectomy (p. 270).
After the above age, the increasing hardness of the nucleus, and the
increasing irritability of the iris, render the method unsuitable.

Discission is a safe procedure, when used with the above indica-
tions and precautions. Iritis should not occur, with perfect asepsis,
indeed it is much more liable to be met with if a linear extraction
be subsequently done.

Another danger consists in glaucomatous increase of tension
(secondary glaucoma), which may come on without any subjective
symptoms — although severe pain usually attends it — while the
absorption of the lens is still running its proper course. It may
happen, consequently, that, when absorption of the cataract is com-
pleted, the eye will be found blind from glaucoma. Frequent
testings of the tension of the eye during the cure are therefore a"lnost
important precaution. Should the tension rise, removal of the lens
through a linear incision in the cornea is at once indicated.

Dislocation of the Crystalline Lens. — This may be congenital
(p. 294), or it may be the result of disease, such, for example, as
anterior sclero-chorioiditis ; or it may be caused by a blow on
the eye.

The dislocation due to disease or trauma may be partial or
complete. Partial dislocation is often so slight as to be discoverable
only when the pupil is widely dilated, the margin of the lens becoming
then visible, by aid of the ophthalmoscope mirror, as a curved black
line in some one direction ; or, the displacement may be so great
as to bring the margin of the lens across the centre of the undilated
pupil, in which case one part of the eye will be highly hypermetropic,
while in another part it will be myopic. Complete dislocation may
take place into the anterior chamber, into the vitreous humour, or
even under the conjunctiva (Fig. 69), if the sclerotic have been
ruptured.

cHAr. X.] THE CRYSTALLINE LENS. 295

The symptoms in partial dislocation are those of loss of power
of accommodation, and monocular double vision. Iridodonesis {i.e.
trembling of the iris when the eye moves) is present, as a rule, in
consequence of the loss of support provided for the iris by the lens.
The anterior chamber is caused to be shallow at one part by pressure
of the dislocated lens against it, while at any part where the lens
does not press against the iris it is deep. In complete dislocation
the symptoms are those of aphakia — i.e. extreme hypermetropia,
and want of power of accommodation.

Treatment. — In partial dislocation it is rarely that any treatment
can be of service. The prescribing of spectacles suited, so far as it
is practicable, to the faulty refraction is indicated. In complete
dislocation of the lens into the anterior chamber, its extraction is
usually required, especially if it cause symptoms of irritation. It
is advisable to fix the lens with a discission needle before extracting
it with the spoon, otherwise it may slip back out of sight. Dis-
location into the vitreous humour is generally unattended by
irritation ; but when the latter does arise, removal of the lens by
aid of a spoon, through a peripheral corneal incision, has to be
attempted, but the patient should be warned that enucleation may
be necessary in case of failure to remove the lens.

Congenital Defects of the Lens. Congenital Cataract (pp. 268, 209,
271).

Ectopia of the Lens (Congenital Dislocation). — This is often hereditary,
and often present in more than one member of a family. The displace-
ment is more frequently in an upward direction than in any other. It
is usually in both eyes. It is due to a mal-development of the zonula of
Zinn, which in these cases is shorter in the direction towards which the
lens is luxated. Discission or extraction is not indicated here. Occa-
sionally some advantage is gained for \asion by the correction with glasses
of one or other portion of the doubly refracting eye.

Coloboma of the Lens. — Coloboma of the lens often co-exists with colo-
boma of the iris (p. 223), but may be present alone. It is generally in
the lower periphery of the lens.

Lenticonus. — This is a rare congenital anomaly of the lens, in which
its anterior surface, or, still more rarely, its posterior surface, is cone-
shaped. The derangements of vision are very smilar to those caused by
conical cornea.

Aphakia (a, prk. ; c^aKo'?, a lentiL lens) , or Absence of the Crystal-
line Lens. — The emmetropic eye after the removal of a cataract
becomes highly hypermetropic, and its power of accommodation is

296 DISEASES OF THE EYE. [chap. x.

lost. Consequently, in order that the eye may have the best possible
sight for distant objects, a high convex glass has to be experimentally
found to suit it, and yet stronger lenses must be prescribed for
shorter distances.

The degree of vision obtained varies considerably in different
cases ; frequently V = J is obtained, but V = y^ may be regarded
as a satisfactory result ; and even lower degrees, which enable the
patients to find their way about with comfort, are classed as suc-
cessful operations. The vision often improves for some months
after the operation, patients who at first obtained only y^, or so,
advancing up to ^ or J. For reading, writing, etc., at about 25 cm.,
a still higher convex glass must be provided. If the correcting lens
for distant vision be, as is usually the case, + 10 D, its power, for
the purposes of vision at 25 cm., must be increased by the lens which
would represent the amplitude of accommodation from infinite
distance up to 25 cm. This lens is 4 D (because VV- = 4) ; therefore
+ 14 D is the lens required for reading, etc. With these two lenses
the majority of cataract patients are satisfied. For distinct vision
at middle distances, they learn to vary the power of the lenses by
moving them a little closer to, or farther from, the eye ; but, if
necessary, a lens can be prescribed for distinct vision at any desired
distance.

In the case of hospital patients, one is often obliged to select the
+ glasses a -fortnight or three weeks after the operation, but the
result is more satisfactory when the selection can be postponed for
six weeks or two months. Permanent wearing of the + glasses
should not be permitted until all redness of the eye has passed off,
and the time at which this occurs varies in different cases. Until
then, also, dark protection spectacles should be worn.

In the majority of cases, after cataract operations, the best
vision is not obtained unless a certain degree of astigmatism is cor-
rected. This astigmatism is caused by a flattening of the vertical
meridian of the cornea, due to the cicatrix at its upper margin, and
hence it is against the rule (chap, xvi.), so that the axis of the +
cylinder is generally parallel to the incision. An obliquity in the
incision often produces an obliquity in the principal meridians of the
astigmatism. The degree of astigmatism varies, and may be very
high. It rapidly reaches its maximum after the operation, and
then gradually diminishes for weeks or months, and in some cases

CHAP. X.] THE CRYSTALLINE LENS. 297

completely disappears ; hence it is tliat glasses for permanent use
can be better prescribed a month or two subsequently to the opera-
tion. We have found that corneal incisions give rise to higher
degrees of astigmatism than operations with a conjunctival flap.

The prismatic action of strong cataract lenses outside the central
axis interferes with clear peripheral vision, and this has been to a
very large extent obviated by lenses invented by Gullstrand with a
special curvature. They are called " aspherical " lenses.

CHAPTER XI.

DISEASES OF THE VITREOUS HUMOUR.

The vitreous humour is an inert body, and with the exception of some
congenital abnormalities, the diseases affecting it are mostly secondary
to lesions of the uveal tract or retina.

Purulent Inflammation of the Vitreous Humour occurs only as
the result of perforating injuries, or of the lodgment of a foreign body,
or as an extension of a purulent process from the chorioid (p. 192).

Ophthalmoscofically , a purulent deposit in the vitreous humour
gives a yellowish reflection, when light is thrown into the eye with
the ophthalmoscope mirror, or on examination with oblique light.

The condition, if at first confined to the vitreous humour, usually
soon extends to the surrounding tissues, and leads to panophthal-
mitis (p. 192) and complete destruction of the eye.

But, in some cases of purulent chorioiditis, where the inflam-
matory process is not very acute or violent, there may be little or no
outward signs of inflammation — there may be no iritis or irritation
of the eye. In these cases difficulty is often experienced in making
a diagnosis between abscess of the vitreous and glioma of the
retina, in w^hich latter disease, too, a whitish or yellowish reflex
is obtainable from the vitreous chamber. These cases of ' quiet '
purulent infiltration or abscess of the vitreous humour (so-called
pseudo-glioma), the result of subacute purulent chorioiditis, occur
in cerebro-spinal meningitis, the acute exanthemata, with foreign
bodies in the vitreous, and under some other as yet obscure con-
ditions. Tubercle of the chorioid may also give rise to the appear-
ance. The history of the case and low tension of the eye in abscess
are often the only guides in diagnosis ; but iritis, or posterior
synechia, and retraction of the periphery of the iris, with bulging
forwards of its pupillary part, and turbidity of tlie vitreous, if these
be present, speak for abscess, while a lobulated appearance is not

298

CHAP. XI.] THE VITREOUS HUMOUR, 299

SO common as in glioma. Occasionally, however, a sure diagnosis
is not only difficult, but impossible. Yet if a case of abscess of the
vitreous humour be taken for glioma of the retina, the error is not
practically serious, for if excision of the eyeball be recommended
for a case of abscess it will be done on an eye which is hopelessly
blind, and which would become phthisical and disfiguring. The
diagnosis may perhaps be assisted by means of transillumination
(p. 218).

Inflammatory Affections of the Vitreous Humour, other than
the purulent form, are for the most part the consequence of diseases
of the chorioid (including those which accompany high myopia,
chap, xvi.), ciliary body, or retina, and display themselves as opa-
cities of various kinds. These are either cells derived from the
primarily diseased tissue, or they are secondary changes (connective
tissue development) in the vitreous humour, the result of the cellular
invasion.

The chief Varieties of Vitreous Humour Opacities are : — (1) A
Dust-like Opacity characteristic of syphilitic disease of the retina
and chorioid. It may occupy the entire vitreous humour, but is
frequently confined to the region of the ciliary body, or to that of
the posterior layers of the vitreous humour. (2) Flakes and Threads.
These occur with chronic affections of the chorioid or ciliary body,
and may be the result also of hsemorrhages into the vitreous humour.
They invade every portion of the humour. (3) Membranous
Opacities, which are rare, and are probably the result either of
extensive hsemorrhagic extravasations or of chorioidal exudations.

Most of the alterations in the vitreous humour are attended with,
or give rise to, fluidity of it, or Synchysis.^

The Diagnosis of opacities in the vitreous humour is made with
the ophthalmoscope mirror and a not very bright light, or with the
plane mirror (p. 35). If a very bright light and a concave mirror
be employed, the finer opacities will not be readily seen. The pupil
being illuminated, the patient is directed to look rapidly in different
directions, when the opacities will be seen to float across the area
of the pupil, as they are thrown from one side of the eye to the
other in the fluid vitreous.

Opacities in the vitreous can be distinguished from those in the

■■ rriV, together ; \eo}, to pour.

300 DISEASES OF THE EYE. [chap. xi.

lens by the fact tliat the latter are fixed, and are arranged for the
most part in a radiating manner.

Another and very fine method for the detection of delicate
opacities in the vitreous consists in placing a high + lens, say + 10 D,
behind the ophthalmoscope mirror, and then approaching close to
the eye, as in the examination of the upright image. Minute opaci-
ties will then be seen as black dots floating in the vitreous humour.

The ophthalmoscope does not always detect changes in the
chorioid or retina, when opacities are present in the vitreous ; and
in many such cases we are led to the belief, either that the diseased
changes in the chorioid or retina are too fine to be seen with the
ophthalmoscope, or that they are situated in the region of the
ciliary body which is out of view.

When the optic disc is viewed through a vitreous humour full
of fine opacities, it appears redder than the normal, as does the
sun on a foggy day, and it may be difficult to decide whether or
not neuritis is present.

Vision is affected by opacities in the vitreous humour in pro-
portion to their density, and to the extent to which the vitreous
humour is occupied by them. The patients often observe them as
floating positive scotomata in their field of vision. These entoptic
appearances are caused by the shadows of the opacities thrown, on
the retina.

The Prognosis depends on the cause of the opacities. The dust-
like opacities accompanying specific retinitis are favourable for
absorption, while the flake and thread opacities frequently remain
as permanent obstructions. Moreover, by shrinking, many of the
more organised opacities give rise to detachment of the retina and
consequent blindness.

Treatment. — Opacities of the vitreous humour offer special diffi-
culties in their treatment owing to the torpid metabolism of the
part, and the consequent difficulty in influencing its tissues by in-
ternal remedies. In addition to the medicines suitable for the con-
stitutional state which may be the cause of the opacities, Heurte-
loup's artificial leech, or dry cupping on the temple, is useful ; and
in many cases, soon after the application, a marked clearing up of
the vitreous is apparent.

Sub-conjunctival injections (p. 120) of a 4 per cent, sterilised
solution of chloride of sodium are a valuable treatment for opacities

CHAP. XL] THE VITREOUS HUMOUR. 301

in the vitreous liumour, in many chronic or subacute cases. They
are not used if acute uveitis be present. The injection is repeated
after a day or two, when the swelHng and irritation have subsided.
Usually not more than two or three injections can be oiven in a
week.

Sub-conjunctival injections enter largely, also, into the therapy
of chronic uveal diseases (p. 187, etc.), of certain corneal diseases
(p. 120, etc.), and of some other diseases of the eye (p. 287).

The curative action of these injections depends on the hyper-
cTmia to which they give rise, and the consequent increased supply
to the diseased part of the healing substances of the blood — the
opsonins, bacteriolysins, etc. There is consequently little to be
gained therapeutically in non- purulent cases by the use of solutions
of sublimate, cyanide of mercury, hetol, and so on, in preference to
the 4 per cent, solution of common salt.

Haemorrhage in the Vitreous Humour.— This is often caused
by blows on the eye, which rupture intra-ocular blood-vessels. It
is the result, too, of certain diseases of the retina and chorioid, which
are accompanied by haemorrhages in those membranes ; or, of
disease of the coats of the retinal or chorioidal vessels. It is seen
in old people with atheromatous vessels, and it occurs in pernicious
anaemia, syphilis, and malaria.

Some quite healthy young people of both sexes are liable to
recurrent hsemorrhages in the vitreous humour, which, when they
cease, either leave the vitreous humour clear, or it may remain more
or less opaque. Strands of connective may form in it, or it may
be followed by retinitis proliferans, or by detachment of the
retina. In most cases no satisfactory explanation for the occur-
rence of these haemorrhages in young people can be offered, but in
some, early arterio-sclerosis or tubercular disease of the coats of the
retinal or chorioidal blood-vessels may be the cause. The arterial
tension is often high, constipation is often present, and there may
be epistaxis.

Haemorrhages in the vitreous humour, when viewed with the
ophthalmoscope, present the appearance of black floating masses,
between which the chorioidal reflex appears. If they lie in the
anterior part of the vitreous chamber, close behind the lens, they
may be seen with focal illumination, and then are red. When
the vitreous humour is full of blood, no red reflex can be obtained

302 DISEASES OF THE EYE. [chap. xi.

with the ophthalmoscope, and the pupil looks quite black when
light is thrown into the eye from the mirror.

Treatment. — The constitutional cause, if discoverable, should be
treated. Sub-conjunctival saline injections will promote absorption
of vitreous humour hremorrhages, and the internal administration of
citric acid has been recommended on the ground that an increased
coagulability of the blood is present. If the coagulability of the
l)lood be reduced, lactic acid or calcium chloride is indicated.
Fibrolysin has been employed in these cases apparently with ad-
vantage in some of them. But many of these cases are incur-
able, or undergo only partial cure. In recent cases rest in bed is
important.

Mouches Volantes, Muscse Volitantes, and Myodesopsia ^ are
terms applied to the motes which people frequently see floating
before their eyes, but which do not interfere with the acuteness of
vision, nor can the ophthalmoscope detect opacities in the vitreous
humour, nor any other intra-ocular disease. These motes are most
apparent when a bright surface, such as a white wall or the field of a
microscope, is looked at. Mouches volantes have no clinical im-
portance. Those annoyed with them should be strongly recom-
mended not to look for them, as in that case others are very apt to
become visible. They depend, probably, upon minute remains of
the embryonic tissues in the vitreous humour.

Fluidity of the Vitreous Humour, or Synchysis, is not rare.
It can only be diagnosed with certainty when the humour contains
floating opacities. Low tension of the eyeball does not always
indicate fluidity of the vitreous, although soft eyeballs nearly always
contain fluid vitreous humour. Trembling of the iris (iridodonesis)
is also no sign of fluid vitreous, although it often accompanies it,
but merely indicates that the iris is not supported in the normal
way by the crystalline lens. Defective zonula of Zinn, however, is
often caused by, or is a concomitant of, fluid vitreous ; and, by
causing displacement of the lens, would allow of trembling of the iris.

The causes of synchysis are chorioiditis and staphyloma of the
chorioid and sclerotic, and it also occurs as a senile change.

Fluidity of the vitreous humour is not, j)er se, a condition of
serious import, unless the eye come to be the subject of an operation

^ fxv'ia, a fly ; bfis, seeing.

CHAP. XT.] THE VITREOUS HUMOUR. 303

involving an incision in the corneo-sclerotic coat, when it renders
prolapse of the vitreous more liable to take place.

Synchysis Scintillans is a fluid condition of the vitreous humour,
with cholesterine and tyrosine crystals held in suspension in it.
The ophthalmoscopic appearances are very beautiful, resembling
a shower of golden rain. They usually occur in old people, and
seldom cause any marked deterioration of vision.

Foreign Bodies in the Vitreous Humour and Interior of the
Eye in General. — One of the most common and most serious acci-
dents to the eye is perforation of the sclerotic, or of the cornea and
crystalline lens, by a small foreign body (shot, morsel of iron, copper,
stone, or glass), which lodges in some part of the interior of the eye
— very frequently in the vitreous humour.

The danger threatened by a foreign body in the eye is great.
It is rarely that, whether it remain free, or, as sometimes happens,
become encapsuled, it is tolerated permanently in any part of the
interior of the eye without inflammatory reaction, except when it
lies in the crystalline lens, and there, as a rule, it causes cataract.
Freedom from inflammatory reaction should never be reckoned
on in the management of such a case.

As a rule, foreign bodies in the vitreous, or elsewhere within the
eye, soon produce violent inflammatory reaction. This occurs,
either by reason of infective micro-organisms being introduced into
the eye with the foreign body, or, it may be caused by the oxidisation
of the foreign body, when it is of iron or copper. The form of in-
flammation may be either a plastic or a purulent uveitis, in the
latter case with purulent infiltration of the vitreous humour and
hypopyon.

Foreign bodies of copper are more likely to cause purulent
inflammation than those of any other kind.

Should a foreign body of iron or steel remain in the eye long
enough — months or years — without giving rise to inflammatory
reaction, it is apt to cause siderosis, or rusting, of all the tissues of
the eyeball, the iris becoming of a reddish brown hue. Cyclitis
and intra-ocular haemorrhage follow, accompanied by much pain,
vision is lost, and the eye has to be excised.

Consequently, when an eye contains a foreign body that is not,
or cannot be, at once removed, the eye may be regarded as lost.
Moreover, such an eye becomes one of the surest sources of sym-

304 DISEASES OF THE EYE. [chap. xi.

pathetic ophthalmitis, when it is plastic and not purulent inflam-
mation tluit is set up in it.

As soon as the case is seen, the first question to be asked of
the patient is : What was the size of the foreign body ? A minute
foreign body, especially if it fly against the eye with force, is likely
to perforate the walls of the eyeball and to lodge in its interior ;
while a large foreign body may cause a perforating wound, but
may then fall to the ground. The second question to be asked is :
What was the foreign body made of ?

It is, therefore, of the utmost importance to decide whether or
not a foreign body be in the eye ; and if one be there, to remove
it if possible, should a reasonable prospect of saving even partial
sight exist ; and this, too, without delay. When the foreign body
cannot be removed, the eyeball must be excised.

Means of deciding objectively ivhether a Foreign Body he in the
Fyc. — If the case be seen immediately, or soon after the accident,
and there be no intra-ocular haemorrhage to obscure the view, the
foreign body may perhaps be detected with the ophthalmoscope
in the vitreous humour or fundus oculi as a dark or glittering body,
according to its nature ; and focal illumination with dilated pupil
will often help the surgeon to discover a foreign body situated
in the anterior part of the vitreous humour. Or, if it cannot be
seen, an opaque streak through the vitreous humour, one end of
which corresponds with the sclerotic wound, may indicate the
track taken by a foreign body.

In case the foreign body have perforated the cornea, and reached
the vitreous humour through the circumlental space, a counter-
opening will be found in the iris ; while, if it be supposed to have
passed through the cornea and lens, the openings both in the anterior
and posterior capsule of the lens should be sought for.

In cases where the ophthalmoscope and focal illumination fail
us, owing to extravasation of blood, traumatic cataract, etc., it
is sometimes not easy to say whether the foreign body be in the
eye, or whether it may have merely punctured the sclerotic, or
cornea, and then fallen to the ground, without passing into the eye.

The Rontgen Rays must then be resorted to, should the foreign
body be of any metal or of glass, to decide both upon its presence
and position, and the Sideroscope is useful for the same purposes,
but only if the object be of iron or steel.

CHAP. XI.]

THE VITREOUS HUMOUR.

305

The following is Mackenzie Davidson's method for employing the
Rontgen Rays in these cases : —

The patient sits upon a chair in an upright position, with his head
fixed in a headpiece (clamped to a table) to keep it steady (Fig. 107), while
at the same time a photographic dry plate can be placed against the
temple on the side of the eye which is to be photographed.

Fig. 108 is a picture of a patient's head in position for taking the right
eye. The back of the head rests against a board, and another board, with
a thumb-screw sliding in a groove, serves to press and fix his head laterally
against two stretched piano-wires, behind which again the photographic
plate is placed. The chin is supported on an adjustable projection.

Fig. 109 is a side view of the same patient. The stretched piano-wires
are shown. The patient, while the skiagram is being taken, is made to
fix his gaze on a distant object, so that his optic axis is parallel to the

Fig. 107.

horizontal wire. Previously, a small piece of lead wire, exactly. 1 cm.
long, is placed on the lower eyelid, and secured by two strips of adhesive
plaster, and the relative position of the point of the wire (nearest the eye)
is carefully noted in relation to the cornea {e.g. so many millimetres
vertically below the centre of the cornea, or so many millimetres vertically
below any corneal scar which may happen to be present) ; also whether
the point is on a level with a vertical line from the centre of the cornea
(as it usually is), or how far behind or in front of this plane. These are
all the adjustments necessary to be made w^ith the patient.

Before the patient is placed in position, the Crookes tube is adjusted,
so that the fine point on the anode, from which the linear rays originate,
shall be exactly opposite the point of intersection of the two stretched
piano-wires. When the tube is worked by the coil, this point shows as
a bright incandescent spot on the anode, if it be of osmium ; and by means
of a fixed ' sight,' placed on this side of the wires, the tube can be so
adjusted that this point is exactly opposite the intersection of the wires.
The distance is carefully noted : it is usually 28 to 30 cm. The tube-
holder is fixed to a bar of wood, which slides horizontally, and by means
of marks placed on the bar itself, and upon the edge of the groove in

30 ft

DISEASES OF THE EYE.

[chap. XT.

which it sHdes, it can be displaced in a plane exactly parallel to the hori-
zontal wire. It is to be displaced 3 cm. to one side of the vertical or zero
point. Then a photographic plate, protected, as usual, in black paper,
is placed against the wires (Fig. 109), and an exposure given of from ninety
seconds to two minutes. With exceptionally good osmium tubes ten
seconds is enough. The tube is then displaced 3 -cm, to the other side of
the zero point — the photographic plate having been removed and a fresh
one put in its place— and a second similar exposure is given. The result
is two negatives taken from two points of view cm. apart.

A transparent sheet of thin celluloid has two cross lines marked upon
it at right angles to each other. One side is varnished, so that it will
readily take pencil marks. Immediately after development and fixing,

11^ ^ Ml i ■

Fig. 108.

this sheet of celluloid is placed over the film side of the negative, so that
its two lines are exactly superimposed upon the white lines left by the
wires in the headpiece ; while firmly held in position, the shadow of the
leaden wire or landmark, placed on the lower eyelid, is carefully traced.
Then the foreign body is traced in the same way. This process of tracing
is repeated with the other negative. The result is that upon the sheet
of celluloid two tracings of the leaden landmark wire, and two tracings
of the foreign body, side by side, are obtained.

This celluloid tracing is now placed upon the horizontal glass stage of
the Cross-Thread Localiser. The latter has two fine silk threads coming
from two points, which are so adjusted as to occupy relatively the two
positions occupied by the anode of the Crookes tube, and to be at the
same distance from the celluloid tracing, and also in the same relative
position to the cross-lines, that the anode of the Crookes tube had to the
photographic plate and to the cross-wires of the headpiece, when the photo
graphs were being taken.

The silk threads are now used to trace the linear paths of the rays.
The intersection of the two threads fixes the position of the object in space.

CHAr. XT.]

THE VITREOUS HUMOUR.

307

Its geometrical relations to the known data can then be measured. First,
the three co-ordinates of the known point are ascertained, then the three-
co-ordinates of the unknown foreign body, and then, by simple subtrac-
tion, the minor co-ordinates are obtained, and thus the position of the
foreign body is accurately determined. The observer is enabled to say
liow far horizontally inwards or outwards the foreign body lies from the
point of the landmark lead wire ; from that point how far vertically
upwards or downwards it lies ; and finally, how far directly backwards,
parallel to the visual axis, it is situated. If care be taken, the position
of a foreign body, however small, can be ascertained with great accuracy
by this method. Its size also can be discovered. Moreover, the two
negatives are stereoscopic, so that, when viewed either in a Wheatstone's

FiCx. 109.

reflecting stereoscope, or by converging the optic axes, and so fusing the
pictures, a single picture in relief is seen, showing the relative position of
the parts in a very beautiful manner.

The Sideroscope is used for the detection of the presence of particles of
steel or iron in the eye. It consists in a magnetic needle hung by a fine
thread, and so mounted that when it is brought close to the eye containing
the foreign body, its deflections can be read by means of an astronomical
telescope which is attached. The sideroscope is vised, too, for ascertaining
the position of the foreign body, which is nearest to the part where the
deflection of the needle is greatest. This, of course, is only an approxi-
mate localisation, and the method is not much employed in these countries,
as the Rontgen Ray method fulfils the requirements more completely.

When it has been decided that a foreign body is in the eye, and when
its position has been determined, its removal must be attempted.

308 DISEASES OF THE EYE. [chap. xi.

Removal of a Foreign Bodij from within the Eye. — The facility
with which foreign bodies can be removed from the eye will depend
upon their position, upon the length of time they have been in the
eye, and upon whether they be magnetic or not.

A. Magnetisable Foreign Bodies. The removal of particles of iron
or steel is more often successful than if the foreign body be of some
other substance ; for, in these cases, the magnet renders valuable
aid, and makes it unnecessary that the foreign bodies should be
visible, if they have been localised by the Rontgen Eays. And
even localisation with the Rays may be foregone, where, in a quite
recent case, it is important there should be no delay in removing
the foreign body.

There are two kinds of magnets, the small or hand magnet, and
the large or giant magnet, and the methods of using them are
essentially different. The small magnet can only attract bodies a
few millimetres away, and it is almost always necessary to introduce
the magnet point into the eye, thereby increasing the risk of sepsis,
and of injury, whereas with the large instrument the foreign body
can be withdrawn from the deeper parts of the eyeball without
bringing the magnet into contact with the eye.

Fig. 110 represents one of the small electro-magnets (Snell's) in
two-thirds its actual size. It is a core of soft iron, around which is
placed a coil of insulated copper wire, the w^hole enclosed in an ebonite
case. To one extremity of the instrument are attached the screws
to receive the connections of a small accumulator. At the other
extremity the core projects just beyond the ebonite jacket, and is

Fio. 110.

tapped, and into it the point is screwed. Points of various kinds or
shapes can be adjusted to the magnet, according to the case to be
dealt with. A sterilised point adjusted to the magnet having been
passed throu<ih the sclerotic opening, it is advanced towards the

CHAP, xr.]

THE VITREOUS HUMOUR.

309

foreign body, wlien the latter adheres to it, and is withdrawn towards
the wound. Much care is required in drawing the foreign body
through the opening, lest it be rubbed of! the point in its passage.
A forceps is generally used at this part of the proceeding, either to
dilate the wound, or to seize the foreign body and extract it. As
short and as large a point as is consistent with the particular case
should be employed, so that the greatest possible power of attraction
may be obtained. A quart bichro-
mate battery, or the street current,
is used. When the foreign body
is embedded in the coats of the
eye at the back, or in a mass of in-
flammatorv effusion, or is entangled
in the ciliary region, difficulty or
failure in the extraction is likely to
be experienced. When a trau-
matic cataract is present, it is well
to combine its extraction with that
of the foreign body, which latter is
fetched out tlirough the cataract
incision with the magnet.

Haab's Giant Electro-Magnet is
represented in Fig. 111. It is an
immense and very powerful magnet,
to which the eye is brought close
Care is required in its use, lest even
more injury be done to the delicate
tissues of the eyeball by the foreign
body in its passage towards the
magnet, than by its entrance into
the eye. As a rule, it is recom-
mended that the centre of the
cornea, in the first instance, be
brought opposite and close to the point of the magnet ; for, by so
doing, entanglement of the foreign body in the ciliary processes,
from which it is not easy again to disengage it, may best be avoided.
Foreign bodies which are in the vitreous humour, or which are not
too firmly fixed in the retina, slide round the lens and bulge the
iris forwards. As soon as this occurs the current is switched off

Fig. 111. — Haab's Giant
Electro-Magnet.

310

DISEASES OF THE EYE.

[chap. XI.

by depressing the pedal with the foot, and the patient's head with-
drawn from the maj^net. The patient usually feels a sensation of
pain and draws his head back involuntarily, and Haab claims that
this is one of the advantages of his method of procedure, inasmuch
as the patient by this movement prevents the lodgment of the foreign
body in the ciliary region or iris. When it has advanced behind the
iris, the patient is requested to rotate the eye towards the side where
the particle lies, so that the magnet, when the current is again
switched on, will exert a vertical or lateral pull, as the case may be,
and draw the particle into the anterior chamber (Fig. 112) through
the pupil, which has been well dilated with
atropine and cocaine. Should it not be
possible to get the foreign body away from
behind the periphery of the iris with the
magnet, an iridodialysis may be formed with
a keratome, and the foreign body drawn
away with a Snell's magnet or with a forceps.
One should not attempt to draw the foreign
body by the magnet through the iris, or else
the latter may be partially or entirely pulled
away. Having got the foreign body into the
anterior chamber through the pupil, an in-
cision with a Grsefe's knife is made in the
cornea, if possible without allowing the
aqueous humour to flow away, and the in-
cision is brought opposite to the tip of the giant magnet and
lightly pressed against it. If much aqueous be lost, it is necessary
to wait until it collects again, or the point of the small hand
magnet is introduced into the anterior chamber. Even foreign
bodies which enter through the sclerotic are best removed through
the anterior chamber. When the foreign body is firmly fixed, it
may often be loosened by switching the current rapidly on and off,
or it may first be drawn towards the equator, and then towards the
anterior chamber.

Haab recommends that no time should be lost in removing a
foreign body, and for this reason he applies the magnet even before
attempting to localise the foreign body by the X-rays or sideroscope.
The occurrence of pain in the eye when the magnet is used is in
itself diagnostic of the presence of a foreign body.

Fig. 112.— The
numbers 1 and 2 in-
dicate the first and
second positions of
the magnet and the
corresponding move-
ment of the foreign
body.

CHAP, xi.l THE VITREOUS HUMOUR. '311

It should be remembered that some varieties of iron amalgams,
e.g. those containing chromium or aluminium, become non-magnetic,
also that shot sometimes is made with iron and is then magnetisable.

B. Non-Magnetisable Foreign Bodies. If the foreign body be of
some substance other than iron or steel — glass, copper, stone, etc. —
it may sometimes be removed through an incision in the sclerotic,
which is either an enlargement of the opening made by the foreign
body, or is a special one, at a point more nearly corresponding with
the actual position of the foreign body in the eye. In a few cases
the foreign body can be kept in view with the ophthalmoscope
while it is being seized and drawn out. The incision should lie
between two recti muscles, should have an antero-posterior direc-
tion, and, in order that it may gape but little, should be a
puncture with a broad keratome. Prolapse of the vitreous is
then produced by pressure on the eyeball, and the foreign body is
evacuated.

This method may be employed only when the foreign body
is situated in the periphery of the vitreous, and towards the equator
of the eye, where the opening for its exit can be made in its immediate
neighbourhood ; but the proceeding is often attended with dis-
appointment, much vitreous being lost, while the foreign body
remains in the eye.

In Sach's procedure, which is a good one, the operation is per-
formed under general anaesthesia in a darkened room, and the
interior of the eye is lighted up by transillumination with a special
transilluminator, through the cornea or sclera. The lips of the
wound are held apart with small retractors, and it may then be
possible to see the foreign body through the wound.

It is sometimes preferable to make the opening not close to the
foreign body, but exactly at the opposite side of the eyeball, by
which means the foreign body can often be reached with greater
ease, and with less injury to the tissues.

One should not be too sanguine of the ultimate result in cases
even of successful removal of a foreign body by means of the magnet
or otherwise, as later on degenerative changes sometimes spoil what
at first promised to be a brilliant result.

Cysticercus in the Vitreous Humour was not, until late years,
very rare in some parts of Germany, but there have not been many
cases observed in the British Isles. We have seen one case of

312 DISEASES OF THE EYE, [chap. xi.

cysticercus in Ireland and also a much rarer parasite, so far as the
eye is concerned, namely the echinococcus.

The original seat of the cysticercus is usually beneath the retina
(chap, xii.), through which it breaks to reach the vitreous humour;
but it also sometimes makes its first appearance in the vitreous. It
is recognised by its peculiar somewhatdumb-bellshape, its iridescence,
and its peristaltic motions. The vitreous humour often becomes
full of peculiar membranous opacities, as a consequence of the
presence of the cysticercus.

Treatment. — Removal by operation. The prospects for the eye
are very much worse than in the case of a sub-retinal cysticercus.

Blood Vessels are sometimes formed in the vitreous humour.
They spring from the retinal vessels, especially in the neighbourhood
of the optic disc, often in connection with connective tissue forma-
tions which accompany haemorrhages ; but sometimes small loops
arise in the neighbourhood of the disc, without any h?cmorrhagic
disease.

Persistent Hyaloid Artery. — In intra-uterine life the hyaloid
artery is a prolongation of the central artery of the retina, and
runs from the papilla to the posterior surface of the crystalline
lens. It completely disappears prior to birth, except in those rare
cases where it remains as an opaque string, which may stretclTthe
whole way from papilla to lens, or may extend only part of the
way. It is then thrown into Avave-like movements by the move-
ments of the eyeball, and is easily recognised with the ophthalmo-
scope. It does not usually cause any disturbance of vision.

CHAPTER XII.

DISEASES OF THE RETINA.

Diseases of tlie Retina may be conveniently grouped as follows
for the purpose of description : — Circulatory Phenomena; Inflam-
mation (Retinitis), Retinal Hsemorrhages and allied diseases,
Diseases of the Blood Vessels, Atrophy and Degeneration, Injury by
Strong Light, Tumours, Parasitic Disease, Detachment, and Trau-
matic Affections.

Alterations in the Retinal Circulation.

Hypersemia and Anaemia of the retina, due to changes in the
capillary vessels, cannot be seen with the ophthalmoscope, hence
these terms are used to denote apparent enlargement of diminution
of the principal branches of the central vessels. Venous Engorge-
ment may occur as a local condition, as in papillitis, retinitis, throm-
bosis of the central vein, or as part of general venous obstruction
in cardiac and pulmonary diseases. Contraction of the Arteries
may also be due to local disease of the vessels (embolism, albuminuric
retinitis, etc.) and spasm (malaria, quinine), or, more rarely, to
diminished blood supply from general causes (cholera). The
opposite conditions, namely, diminution in the size of the veins, and
dilatation of the arteries, are rarely noticeable.

Pulsation of Retinal Vessels. — Pulsation in the Retinal Veins
is present under normal conditions in some eyes, and can be produced
by slight pressure on the eyeball in all eyes. It is best observed
on the optic disc and in the upright image. In cases of insuffi-
ciency of the aortic and tricuspid valves, the venous pulsation is
often very marked, and extends some way into the retina. Pulsation
in the Retinal Arteries in a slight degree can be detected in about
36 per cent, of noi'mal eyes (Ballantyne). But great care is required

313

314 DISEASES OF THE EYE. [chap. xii.

in order to satisfy oneself of its presence, and pulsatory movements
communicated to the patient's head, or movements of the ophthal-
moscope in the observer's hand, must be carefully excluded. Arterial
pulsation may appear as a movement of the vessel as a whole (loco-
motor pulse), when it is best seen at a curve, or as an alternate
contraction and dilatation of the vessel (expansile pulsation). A
' capillary pulse ' is only seen in aortic regurgitation, and appears
as an alternate blanching and reddening of the optic disc, similar
to the capillary pulse seen under the finger nails. Another
variety of pulsation is the ' pressure pulse ' due to increased intra-
ocular pressure, as seen in glaucoma, or when digital pressure is
exerted on the normal eye. Arterial pulsation occurs also in
some cases of mitral disease, in exophthalmic goitre, and sometimes
in ansemia.

Inflammation of the Retina : Retinitis.

Retinitis, in general, is characterised by the following ophthal-
moscopic appearances : diffuse cloudiness, especially of the central
portion of the fundus, due to loss of transparency in the retina,
and consequent veiling of the chorioid ; the optic papilla becomes
more or less congested, with indistinctness of its outline, Avhich
in the erect image resolves itself into a delicate striation ; vascular
engorgement, the retinal veins especially becoming enlarged and
tortuous. The inflammation in some cases may subside at this
stage, but as a rule haemorrhages and whitish exudations soon make
their appearance.

The various forms of retinitis are distinguished by the pre-
dominance of some of the above signs, and also by the peculiar
appearance and grouping of the exudations.

If the optic papilla be not merely congested, but also swollen,
the condition is called Neuro-Retinitis.

In some cases of retinitis the chorioid is also involved, and to
these the name Chorio-Retinitis is given.

Inflammation of the retina is rarely a local affection, being in
the majority of cases due to general diseases, and hence it most
commonly occurs in both eyes.

Syphilitic Retinitis (or Syphilitic Chorio-Retinitis). (Plate III.
Fig. 1). — Inherited or acquired syphilis is liable to induce a form

CHAP. XII.] THE RETINA. 315

of clironic diffuse retinitis. In the acquired disease it is a later
secondary symptom, coming on between the sixth and eighteenth
month, and often in one eye only.

With the Ophthalmoscope a slight opacity of the retina is seen
extending from the papilla some distance into the retina, and
very gradually disappearing towards the equator of the eye. The
papilla is but slightly hyperaunic, while its margins are indistinct,
like those of the moon seen through a light cloud. The artery is
not generally altered, and the vein is but slightly distended.
Opacities in the vitreous humour are not uncommon. They may
be membranous or thread-like, but a diffuse dust-like opacity,
filling the whole vitreous humour, is almost pathognomonic of a
syphilitic taint (p. 299), and often creates much difficulty in the
ophthalmoscopic diagnosis of the retinal affection.

Disseminated chorioidal changes in the form of small yellowish
spots with pigmentary deposit, are very frequent, especially towards
the equator of the eye. Many observers, indeed, hold that the
whole process is primarily in the chorioid, and that the retina is
only secondarily affected. Fine whitish dots and pigmentary changes
often occur about the macula lutea.

The hereditary form of the disease sometimes bears a resemblance
to retinitis pigmentosa, but the pigmentation is not so delicate,
indeed in some cases there is massive pigmentation, and often it is
mingled with small white atrophic spots giving rise to an appearance
like pepper and salt. Atrophy of the optic disc and white lines along
the vessels are often seen. The disease may be ante-natal.

Occasionally, instead of the diffuse retinitis, syphilis causes a
circumscribed yellowish-white exudation in the neighbourhood of
the macula lutea, or on the course of one of the large retinal blood-
vessels.

Vision may be but slightly affected, but in the advanced stages
it is usually much lowered. Central, or peripheral, or ring scotomata
(Fig. 19) or concentric defects of the field, are found. The scoto-
mata are often positive — i.e. they can be seen by the patient as
dark spots in the field. Night-blindness is a constant symptom, and
the light-sense is enormously diminished. The patients sometimes
complain of sparks or lights, which seem to dance before their
eyes, and occasionally also of a diminution in the size (micropsia)
of objects, or of a distortion (metamorphopsia) of their outlines.

31() DISEASES OF THE EYE. [chap. xii.

The micropsia is believed to be due to a separation from each
other of tlie elements of the layer of rods and cones by sub-retinal
exudation. The image of an object then comes into relation with
fewer of these elements, and hence the mental impression is that
of a smaller object than is conveyed by the image formed in the
sound eye, or on a sound part of the same retina.

The Progress of the Disease is very slow, and is liable to relapses.
In the late stages extensive pigmentary degeneration of the retina
may come on, or disseminated chorioiditis (Plate III. Fig. 1). But
if the case come under suitable treatment in an early stage, a cure
may often be effected.

Treatment. — The only remedy which has been of real value is
mercury, and that in an early stage. Probably salvarsan will prove
useful. Mercury should be used in a protracted course of some
weeks by inunction, combined at discretion with small doses of
calomel internally. Or, the method by intra-muscular injection
of mercury may be employed. If mercurialisation be effected, it
should not go further than very slight stomatitis. Turkish baths,
and the artificial leech at the temple, may be employed as adjuncts
to the treatment. When the mercurial course has been completed,
iodide of potassium should be prescribed as an after-treatment.
Complete rest of the eyes, and protection from strong light by dark
glasses, are also necessary in this, as in many forms of retinitis.

Retinitis Albuminurica occurs as a complication in many cases
of chronic nephritis, in some few cases of acute nephritis, and in the
albuminuria of pregnancy. It is most common with the small
granular kidney, but may attend any chronic form of Bright' s
disease, and occurs in 32 per cent, of these cases, and in 52 per cent,
of those with azotfemia (nitrogenous retention). The arterial ten-
sion is always high when retinitis is present, even in the young.
It is rare in children, reaches its maximum between thirty and
forty years of age, after which it again becomes rarer. It is com-
moner in men than in women.

The Defect of Vision in the chronic form, although often the first
symptom which causes the patient to seek advice, is associated
rather with a late stage of the kidney disease, and with hypertrophy
of the heart. Retinitis may be present before albumen is found in
the urine. Both eyes as a rule are affected, although often not
equally so. Vision is much lowered, and even perception of light

ft iiijtti Iliad X'

PLATE V.

{To face page 316.)

Fig. 1. — There is a slight cloudiness of the retina, veiling the retinal
vessels and the outline of the optic disc. Note the flame-shaped
retinal haemorrhages and round soft-edged white exudations, some
of which lie anterior to the retinal vessels. The fovea centralis is
surrounded by brilliant white radiating lines and dots, the so-called
' star at the macula ' which is very suggestive of albuminuric retinitis.

Fig. 2. — The detached portion of the retina is of a bluish-grey colour and
is thrown into folds, on the elevations and depressions of which the
dark retinal vessels pursue an irregular wavy course. To the right
the detachment is shallower and the retina has partially preserved
its transparency. A triangular rent in the retina is visible to the
left.

Plate V.

Fig. J. Albuminuric Retinitis.

Fig. 2. Detachment of the Retina.

CHAP. XII.] THE RETINA. 317

may be wanting ; there may be enlargement of the blind spot
and central scotomata, but the peripheral field is normal. The
blindness is not always all due to organic changes in the retina,
being often largely the result of uraemia. (See Ur?emic Amblyopia,
chap, xiv.)

OphthaJmoscopie Appearances (Plate V. Fig. 1). — These are
venous hyper^rmia, with oedematous swelling of the papilla, and of
the retina in its neighbourhood ; hjiemorrhages on the papilla, and
in the nerve-fibre layer of the retina ; and round or irregularly
shaped white spots in the retina, arranged in a zone around the
papilla, some three papilla diameters removed from it. These
changes take place in the order enumerated. The hyper?emia and
engorgement of the veins, often very great, become less, according
as the white spots become more developed. Near the macula lutea
no very coarse changes usually occur ; but fine white dots are
found, with a star-like arrangement converging towards the macula.
In some cases these fine white dots are present only on the inner
side of the macula in the space between it and the papilla.

The macular star is also met with in retinitis from diabetes, in
embolism of the central artery, arterio-sclerosis, chlorosis, syphilitic
neuro-retinitis, leuca}mia, and in some cases of papilloedema from
cerebral tumour.

The degree in which all these different changes are present
varies in different cases, no one of them being pathognomonic of
the kidney affection, but rather the grouping of the whole picture
being suggestive. Sometimes the papillitis is so intense as to simulate
that known as congestion papilla in cases of intra-cranial tumour ;
while the white spots are sometimes developed to such a degree
as to become confluent, and to form one large white plaque. Again,
the papillitis, or white spots, or both, may be but slightly marked.
The number and size of the haemorrhages are also liable to great
variation. Detachment of the retina has been observed in a few
cases ; and sometimes the haemorrhages burst into the vitreous
humour.

Some of the white spots are caused by exudations of fibrinous
coagula in the outer layers of the retina (the retinal vessels passing
over them) and of gangliform degeneration of the nerve-fibre layer
(the retinal vessels hidden by them). The white star at the macula
lutea is caused by the deposit of blocks of fibrin, which are dis-

318 DISEASES OF THE EYE. [chap. xit.

tributed radially owing to the anatomical structure of the macula.
Small aneurismal dilatations of the arteries occur very occasionally.

The retinal changes are the result of the renal disease. Cells
containing fat or lipoid substance are also seen in the retina ; some
believe them to be wandering pigment cells which have lost their
pigment. The retinal changes are not caused by arterio-sclerosis,
for the vessels are usually healthy in early stages and in acute and
puerperal cases, although in the later stages of chronic cases they
do become diseased, by retardation of the blood-stream from failure
of the heart, or from diminution in size of the smaller retinal vessels
(Leber).

Prognosis. — In chronic cases the prognosis as regards the patient's
life is bad. The majority die within eighteen months or two years ;
but, if the general disease remain stationary, or improve, or recover,
the retinal changes may improve or disappear, and may leave the
retina with normal appearances and functions ; or, the swelling,
hyperemia, white spots, and hcTmorrhages may give place to optic
atrophy, with diminution in size of the arteries, pigmentary altera-
tions in the retina, and blindness. In the albuminuria of pregnancy,
and in that due to acute nephritis, the retinal complication may
disappear with the renal disorder, leaving good vision.

Treatment. — No treatment other than that for the primary renal
disease is of avail. Taking into consideration the serious import
of this eye-symptom for the life of the patient, it is a question
whether, in many cases of pregnancy with albuminuric retinitis,
abortion should not be resorted to, especially if the pregnancy have
still some months to run. But, on the whole, the prognosis is more
favourable in the albuminuria of pregnancy than in interstitial
nephritis.

Retinal Affections in Diabetes.— There is no one condition of
the retina characteristic of diabetes, although undoubtedly retinal
affections occasionally do complicate it in an advanced stage. The
changes are not suggestive of inflammation, but rather of degenera-
tion. Small retinal haemorrhages, with fine changes in the form
of glistening dots about the macula lutea, somewhat similar in
appearance to those which occur in Bright's disease, except that they
rarely form the well-marked star, are perhaps the most common and
suggestive appearances. In other cases retinal hcTmorrhages alone
are found, and in others thrombosis of the central vein ; while, again.

CHAP. XTT.] THE RETINA. 310

the so-called typical appearances of iiriglit's disease may be pre-
sented. There are often opacities of hfcmorrhagic origin in the
vitreous humour, which, if copious, may destroy vision.

It is an important rule of practice that, in all cases of retinal
hremorrhages and of thrombosis, the urine should be examined
for sugar and albimien. The retinal disease is sometimes the first
indication of the general disorder.

Embolism of the central artery, and thrombosis of the central
vein, have been observed in diabetes.

With the marked lipsemia which is present in some cases of
diabetes, the retinal vessels appear as bright lines on a red back-
ground, the arteries and veins being difficult to distinguish from
each other. This is not due to a fatty embolism of the vessels, but
rather to the blood being altered to a fat-emulsion throughout the
entire system. (See also Glycosuric Amblyopia.)

Retinitis Leucsemica. — In not more than one-third or one-
fourth of the cases of leucocythemia, or pseudo-leuc?emia, does a
retinal affection occur, and it is not always of the same type. It
may consist in a slight diffuse retinitis, accompanied by some ex-
travasations of pale blood ; while the blood-vessels are also pale,
the veins being much enlarged, and flattened rather than over-
distended, the arteries small, and the chorioid of an orange-yellow
colour. Or, it may resemble a case of ordinary hsemorrhagic
retinitis.

The Apfearances most characteristic of the affection are : a pale
papilla with indistinct margins ; slight opacity of the retina, especi-
ally along the vessels ; small haemorrhages ; round, white, elevated
spots up to 2 mm. in diameter, with a hsemorrhagic halo, situated
by preference towards the periphery of the fundus and at the macula
lutea, but not at all, or only in very severe cases, in the zone between
the macula and the equator of the eye. These white spots consist
of extravasations of leucaemic blood, the result, probably, of dia-
pedesis, and they are sometimes distinctly prominent.

Vision may be but little affected if the macula lutea be fairly
free. Haemorrhage into the vitreous humour may cause complete
blindness.

Metastatic Retinitis is observed as the result of septic embolism
of the retinal arteries in septicaemia after surgical operations, etc.,
and very frequently in cases of metria, and it is usually, in the

320 DISEASES OF THE EYE. [chap. xii.

latter condition, a fatal sign. In an early stage the ophthalmoscope
shows a number of small haemorrhages in the retina, with general
cloudiness of the retinal tisues, while the actual embolisms, which
are usually multiple, may not be visible. The inflammation makes
rapid progress, and becomes purulent, soon destroying sight, and
extending to the chorioid, iris, and vitreous humour, until finally
the stage of panophthalmitis is reached. The retina is sometimes
alone the primary seat of the embolic attack, and sometimes the
chorioid is also involved. The embolisms are often little more than
masses of micrococci. Mild cases, which stop short of suppuration,
also occur, and are probably from toxins only.

The retina, of course, becomes secondarily implicated in many
purulent processes, which commence in other parts of the eye.

For Retinitis caused by strong light see Injury of the Eetina
by Strong Light.

Eetinal H.5:moerhages and Allied Diseases.

Retinal Haemorrhages. — Haemorrhages seen with the ophthal-
moscope nearly always have their origin in the retina, and are most
frequently observed in persons over forty or fifty years of age,
although they are not uncommon in the young. Fresh haemorrhages
are bright red, but they become darker in colour after a while, or if
the layer of blood be very thick they even take on a tinge of black.
Their shape varies according to their depth in the retina ; if they be
situated in the nerve-fibre layer they appear flame shaped and radi-
ally striate (Plate V. Fig. 1, and Plate YII. Fig. 2), but when they
occupy the deeper layers they are round or blotchy. Haemorrhages
may be present in any part of the fundus, and may vary in size from
a mere speck to a large patch several times the size of the optic disc.
In some cases, only one or two minute spots of blood are visible,
while in others the whole retina is splashed over with them. They
may break through into the vitreous humour.

Pre-retinal or Suhhyaloid hcemorrhages, in which the blood is poured
out over a fairly large surface, either immediately under the membrana
limitans interna, or between it and the vitreous humour, usually occur
in the macular region. They are semicircular or boat-shaped, their upper
margin being limited by a horizontal line. Ihe red colour disappears in
the upper part of the haemorrhage owing to the subsidence of the blood-
corpuscules. One or more of the retinal blood-vessels may be hidden
from view where they pass under the layer of blood.

CHAP. XII.] THE RETINA. 3^1

Sympmns. — Peripheral haemorrhages may not cause any visual
symptoms appreciable to the patient, otherwise the loss of sight
comes on suddenly and is attended with the development of a posi-
tive scotoma. There may be metamorphopsia. In some cases the
patient notices a reddish cloud before the eye.

Causes. — Eetinal hsemorrhages usually form part of the ophthal-
moscopic picture in optic neuritis and various forms of retinitis,
when they are only of secondary importance. Other causes are
diseased condition of the blood such as pernicious anaemia, leu-
caemia, purpura, scurvy, etc. ; cardiac disease ; diseases of the
retinal blood-vessels, including syphilitic and possibly tubercular
disease, angio-sclerosis, and thrombosis ; in embolism there are
usually few or none.

Retinal haemorrhage may also be caused by irregular or suppressed
menstruation, by severe loss of blood, by venous congestion from pul-
monary stenosis or severe compression of the thorax or neck, and from
pressure during birth in new-born infants.

Of a different origin are the hasmorrhages which result from injury or
sudden reduction of the intra-ocular pressure after operations (see Glaucoma,
Cataract).

The prognosis in cases of retinal haemorrhage depends to a great
extent on the constitutional condition wdth w^iich they are associ-
ated. They may remain unaltered for many months. Sometimes
the blood becomes absorbed without leaving any traces behind, but
if at all large a greyish or white patch is formed, but pigmentation
is less common.

Eetinal haemorrhages, however slight, even though unaccom-
panied by retinitis, must be looked upon with grave suspicion,
more especially when they occur in people past middle age ; for
they may be the forerunners of albuminuric retinitis or furnish the
first indication of diabetes or of local or general angio-sclerosis,
and many of these patients die from cerebral haemorrhage.

Pre-retinal haemorrhages often disappear completely without in-
juring the sight, but they are liable, like most haemorrhages, to recur.

Treatment. — Active measures are of little use. Cold compresses
at first, with a pressure bandage, and dry cupping to the temple,
may be employed. The general state of the patient must be at-
tended to, with rest of the body. Iodide of potassium and sub-
conjunctival saline injections may be of use.
21

322 DISEASES OF THE EYE. [chap. xii.

It will be advisable to describe in this place certain types of
disease wliieli aie closely associated with or directly dependent upon
extravasation of blood into the retina, namely, Ketinitis Proliferans,
Ketinitis Exudativa, and Ketinitis Circinata. Hcijmorrhagic re-
tinitis will be described under Thrombosis of the Central Vein.

Development of Connective Tissue in the Retina, or Retinitis Proliferans.—

Extensive white or bluisli-white striae, formed of connective tissue, are
sometimes seen in the retina, and may even conceal the vessels and
papilla. They project into the vitreous humour, and contain newly
formed vessels, which are prolongations of the retinal vessels. These
striae are the result of haemorrhages especially when near the optic disc,
traumatic or otherwise, and of inflammatory processes. Haemorrhages
in the retina, or in the vitreous humour, or in both, are generally
present at some period. Vision is sometimes but slightly affected, but the
danger of recurrence of the haemorrhages renders the ultimate prognosis
unfavourable as a rule. Detachment of the retina may occur.

This disease is chiefly seen in young people (see p. 301) with relapsing
haemorrhages into the vitreous humour, but it occurs occasionally in those
past middle age.

Treatment. — Heurteloup's leech. Iodide of potassium, or perchloride
of mercury. Lactate of calcium. Thyroid extract. Some cases are on
record where, one eye having been lost from this disease, and the sight
of the other eye seriously threatened, the common carotid was ligatured
on the side of the second eye, with the desired result of arresting the
recurrence of haemorrhages. The effect of the procedure is held to be due
to reduction of the pressure on the walls of the ophthalmic artery.

Retinitis Exudativa (Retinitis Haemorrhagica Externa) (Coats).— This is
a very chronic and insidious disease which occurs in young persons and
only exceptionally involves both eyes. There is usually nothing in the
general health or family history to which the disease can be attributed.

The exudation appears in the shape of one or more prominent opaque
white or yellowish masses, which always underlie the retinal vessels.
Haemorrhages are nearly alwaj^s present on the sxu-face or at the periphery
of the mass. The older exudations may be greenish or tendinous in
appearance. Most cases present evidences of vascular disease, such as
white lines along the vessels, fusiform dilatations, beading, or newly
formed vascular loops, brushes or glomeruli. The disease progresses
slowly for years, with varying changes in appearance, due to fibrous
cicatricial changes in the older masses combined with the formation of
fresh exudations and haemorrhages. The eye is ultimately lost from de-
tachment of the retina, secondary cataract, and iritis with low tension,
or glaucoma may supervene.

The most constant microscopical lesion is a fibrous tissue mass between
the retina and the chorioid, with evidences of degenerative changes. In
many cases the retinal vessels show various forms of disease.

Retinitis Circinata is a rare disease. It occurs mostly in old people,

CHAP, xii.'j THE RETINA. 3^3

chiefly women, but sometimes in the yonng, and is characterised by
remarkable appearances. At tlie macula there is a grey or yellowish
cloudy patch, which may attain the size of the papilla, and sometimes
presents hseinorrhages on its surface ; surrounding tliis, but separated
from it by a healthy zone, is a ring composed of numerous closely set,
small white spots, which are confluent in places. The sight gradually
becomes much deteriorated. A large central scotoma develops, and vision
is finally reduced to finger-counting centrally, although for a long time
the peripheral field may not become contracted. Total blindness rarely
results.

A case has been recorded of complete recovery with disappearance of
the ophthalmoscopic changes. This disease is the result of hsemorrhage,
and is closely allied to exudative retinitis. Coats has indeed recorded a
case of a patient who had massive exudation in one eye and retinitis
circinata in the other, moreover ophthalmoscopic evidences of vascular
disease such as arterio-sclerosis are often present in retinitis circinata.

Capillary Angiomatosis of the Retina (Von Hippel's Disease). — ^This
rare affection begins in the second or third decade of life, but continues
to progress for many years and ultimately ends in blindness. Both eyes
are affected, but a variable interval elapses before the onset of the disease
in the second eye. The ophthalmoscopic appearance, which is very char-
acteristic, consists in the formation, usually towards the periphery, of
oval or spherical pink or yellowish bodies, in which end abruptly two
enormously dilated and tortuous vessels, an artery and a vein, but the
latter is much paler in colour than a normal vein. The small tumour
is composed of a capillary vascular plexus with some supporting neuroglial
tissue. The tumours increase in size while others appear. Haemorrhages
and brilliant white spots are also seen. Finally the retina becomes
detached, with low tension, or glaucoma sets in.

Epistaxis and headache have been noted in several of the cases, and,
in a few, intracranial cysts have been discovered post mortem. The
disease has occurred in two members of a family; its cause is unknown.

Diseases of the Ketinal Vessels.

The vessels of the retina become affected secondarily, in various
forms of retinal disease, and in some of the diseases just dealt with
vascular disease may play a prominent part ; but this section will
be concerned with primary disease of the retinal vessels, with ob-
struction of the circulation in the retina, and with the ophthal-
moscopic evidences of vascular disease.

Sclerosis of the Retinal Vessels.— The arteries are more Hable to
this condition than the veins ; it takes the form of an endo- or
perivasculitis. In the case of the arteries the intima is most
frequently involved, but periarteritis may also occur, while in the
veins endophlebitis is rare and periphlebitis fairly common. Endar-

324 DISEASES OF THE EYE. [chap. xtl.

teritis reveals its presence by narrowing of the blood column, and
perivasculitis by the appearance of white lines along the vessels.
The disease usually begins in the large tiunks on the papilla, and
may not extend much beyond the latter, as in some cases of optic
atrophy (Plate VIII. Fig. 2) ; while in other cases (Bright's disease,
hereditary syphilis) it involves the small branches as well, and pro-
motes thrombosis and retinal apoplexies, and may even ultimately
lead to obliteration of the lumen of the vessels, so that they look like
white branching streaks.

The alterations in the vessels consist in engorgement and tortu-
osity ; centripetal venous pulsation, which, according to Eaehlmann,
is seldom absent ; the arteries become smaller, the light streak
brighter, and the whole vessel is lighter in colour (' silver wire ar-
teries '), its walls become less transparent, and its increased rigidity
is shown by the indentation of the veins where it may happen to
pass over them ; pulsation is more easily produced on pressure than
in a normal eye. In more advanced cases the contour of the vessels
becomes irregular, they may exhibit localised constrictions, or alter-
nate constrictions and dilatations ; further, the constricted portion
of the vessel may be so limited as to involve only a couple of milli-
metres of its length, and is then very liable to be overlooked ; white
shining scale-like spots are sometimes seen on the surface of the
arteries, especially in syphilis (according to Haab) ; finally beading
and varicosity of the veins, aneurismal dilatations of the arteries,
arterio-venous communications and newly formed vascular loops
or glomeruli have all been observed to occur.

Three of the earliest signs are : a corkscrew-like appearance in
the small arterial twigs, especially involving the macular branches ;
' silver-wire ' arteries causing more or less displacement of the
underlying veins, where they cross the latter (Gunn's sign) ; and
lastly, a characteristic dull red colour of the optic disc.

The degree of pressure exerted by the artery on the vein may
be so slight as merely to flatten the vein, or push it aside in the
direction of the blood-current in the artery, while at other times it
may be sufficient to constrict the underlying vein, which then
appears swollen at either side of the artery (so-called " banking "
of a vein) ; or, again, an engorgement of the vein on the distal side
of the artery may show that the circulation in the vein is decidedly
impeded. But in all these cases the artery has lost its transparency.

CHAP, xn.] THE BET IN A. 325

and the vein can no longer be seen underneath it as is the case when
normal vessels cross.

Symptoms. — Unless secondary results ensue such as hsemorrhages
or obstruction of the circulation leading to embolism and throm-
bosis and retinal degeneration, there may be no visual defect.

Etiology. — The changes in the blood-vessels are probably caused
by disturbance of the nutrition, as well as by toxins circulating in
the blood. The conditions which promote it are senility, chronic
nephritis, diabetes, syphilis, poisons such as lead, alcohol, and phos-
phorus. Angio-sclerosis sometimes occurs in the young and is
hereditary. Intestinal auto-intoxication has also been suggested
as a cause.

Obstruction of the Central Artery of the Retina including Em-
boUsm and Thrombosis. — Complete obstruction of the central artery
of the retina, whether it be brought about by embolism, thrombosis,
or by extreme constriction, produces a very definite ophthal-
moscopic picture (Plate VII. Fig. 1). Sudden or very rapid blind-
ness, beginning at the periphery of the field, and advancing towards
the centre, is the only symptom experienced by the patient.

Immediately after the attack, the Ophthalmoscope shows a marked
pallor of the papilla, while the artery and its branches are much
diminished in size or are empty of blood, resembling fine white
threads, and the veins are smaller at the papilla, but somewhat in-
'creased in size towards the periphery. Pressure on the eyeball pro-
duces neither pulsation nor change in calibre of the vessels, as it
does in a sound eye. Usually, within a few hours, the central region
of the retina begins to assume a greyish-white opaque appearance,
consequent on degeneration of the ganglionic layer with perhaps
oedema of the nerve-fibre layer, in the midst of which the macula
lutea is seen as a cherry-red spot. The little blood contained in the
vessels may soon be observed to divide into short columns with
colourless interspaces, and these short columns move along the
vessels with a slow jerky motion. Minute haemorrhages sometimes
occur, most commonly between the macula and the papilla, but
they are never numerous.

The cherry-red spot at the macula lutea is not due to haemor-
rhage. It is a contrast effect, the red colour of the chorioid shining
through, owing to the retina being very thin in this region.

The cloudiness of the retina passes away in a few weeks, and with

326 DISEASES OF THE EYE. [chap. xii.

it the peculiar appearance of the macula lutea, while atrophy of
the retina and papilla supervene. A white star, such as one sees
in albuminuric retinitis, sometimes makes its appearance at the
macula.

In some cases the embolism or obstruction occurs in a branch only
of the central artery. In these cases the cloudiness and the defect
of vision are confined to the part of the retina supplied by the
obstructed branch (Fig. 14).

In obstruction from arterio-sclerosis and thrombosis there is
often a history of previous attacks of transient blindness, in one
or both eyes, and of faintness, giddiness, and headache at the onset
of the blindness.

There is a tendency nowadays on the part of some writers to attribute
most cases of obstruction of the central artery to endarteritis rather than
to embohsm, and the sudden cessation of the circulation, they say, is brought
about by extreme constriction of the vessel, associated with a sudden fall
in the general blood-pressure, in consequence of which the blood can no
longer be forced through the very small lumen. There is no doubt that
in many cases, of so-called embolism, careful examination of the patient
fails to reveal any possible source from which an embolus could originate.
In rare cases, of which we have recorded one lately in a boy, sudden loss
of vision occurs, with the symptoms of obstruction of the retinal circula-
tion, in both eyes. The loss may be simultaneous in both eyes or' there
may be an interval between the onset in each eye. These cases of bilateral
obstruction, unless the loss of vision occurs simultaneously, or nearly so,
in both eyes, often recover fair vision.

Prognosis. — Vision may improve for a time, but when atrophy
commences it falls back ; and, finally, power of perception of light
is lost. Cases of embolism of a branch of the central artery are
more likely to recover.

Causes. — Endocarditis ; mitral disease ; aneurism of the aorta ;
pregnancy ; angio-sclerosis. A few cases of chorea with embolism
of the central artery are recorded. But it occurs, too, in apparently
healthy persons, without any discoverable cause.

Thrombosis is apt to be caused by any condition which slows
the flow of blood, disease of the walls of the vessels, or alteration in
the quantity or quality of the blood.

Treatment. — Paracentesis of the anterior chamber has been
tried with the object of suddenly reducing the tension, and thereby
causing a sudden rush of blood behind the obstruction which may

ciiAr. xiT.] THE RETINA. 327

sweep the latter away. Such attempts have very rarely been suc-
cessful, and can be of avail only if employed almost immediately
after the attack of blindness ; that is to say, before the retinal
tissue dies.

Several cases have been published in which the circulation,
which probably was not completely impeded by the embolus, or
thrombus, was restored, and good vision regained ; the recovery
being probably due to the manipulations of the eyeball made in
each case for the purpose of observing the effect of pressure on
the vessels. In fresh cases, massage of the eyeball suitably applied
would, therefore, always be worth the trial.

Amaurosis Fugax. — Very closely related to the cases of permanent
obstruction, and differing from them probably only in degree, are those
characterised by the occurrence of repeated attacks of sudden but tem-
porary failure of sight, complete or partial.

The obscurations of sight in amaurosis fugax are due to direct inter-
ference with the retinal blood-supply, and are independent of inflammatory
conditions, such as optic neuritis. Sudden blindness from other causes,
such as migraine, hysteria, and cerebral disease must also be excluded.

The paroxysmal failure of sight may occupy a few minutes only, or
last several hours, and may obscure a part or the whole of the field of
vision. It may affect only one eye, or each eye at different times. Occa-
sionally even both eyes are involved at the same time. Again, it may
happen that, after one or more attacks of temporary obscuration, an
attack may occur which ends in permanent loss of sight. Simultaneous
failure of vision in both eyes, of short duration in one eye, but permanent
in the other, has also been observed — a fact which tends to show that
the temporary and permanent attacks of blindness are of the same nature.
Some of the patients seem to have been in very good health. But in
most some form of cardiac disease, angemia, or angio-sclerosis existed.

The general symptoms recorded during the obscurations consisted in
headache, giddiness, and sometimes vomiting and fainting. Symptoms
resembling a mild form of Raynaud's disease were noted in some instances.

It is very probable that disease of the retinal arteries, plus alterations
in blood-pressure, is the true cause of these temporary obscurations of sight,
although some believe that they are due to spasm of the vessels. Ophthal-
moscopic examination during the attacks has revealed constriction of the
retinal vessels and appearances similar to those caused by occlusion of
the central artery.

Thrombosis of the Retinal Vein (Hsemorrhagic Retinitis) is

seen chiefly in old people with atlieromatous arteries, cardiac troubles,
chronic nephritis or diabetes. Orbital cellulitis, due to erysipelas
or other causes, may also produce it.

328 DISEASES OF THE EYE. [chap. xir.

The Ophthahnoscopic Appearances (Plate VII. Fig. 2) consist in
extreme engorgement of the retinal veins, which are very dark in
colour, with great narrowing of the arteries ; the whole fundus is
splashed over with dark haemorrhages ; the optic papilla, which at
first is swollen and congested, after a time becomes pale, and under-
goes atrophy, and the haemorrhages, having become absorbed, leave
an atrophied retina with thready arteries. Secondary thrombosis
may occur in the central artery, and then a white cloudiness of the
retina will appear in addition to signs of venous thrombosis. If the
thrombosis be confined to a branch of the central vein, the ophthal-
moscopic appearances will be limited to the corresponding portion of
the retina, owing to the absence of anastomosis in the retinal vessels.

The Prognosis is very bad, sight becoming permanently damaged
or lost. It is more favourable when a branch only is thrombosed.

Treatment must be directed to the general condition. In many
cases secondary glaucoma comes on in a rather acute form, and it is
therefore advisable not to use atropine, in case it might precipitate
an attack. A highly albuminous exudation takes place, which
blocks the spaces of fontana and canal of Schlemm, and thus the
intra-ocular tension is raised ; hence the angle of the anterior
chamber is often open in these cases and therefore iridectomy or
trephining is not of much avail, and enucleation often becomes
necessary for the relief of pain.

Atrophies, and Degenerations, of the Eetina.

Retinitis Pigmentosa is a degenerative, rather than an inflam-
matory, affection of the retina. It is extremely chronic in its pro-
gress, coming on most commonly in childhood, and often resulting
in complete, or almost complete, blindness in advanced life.

Vision is much affected, but the symptom chiefly complained
of is night-blindness, due rather to defective power of retinal adap-
tation than to defective light-sense. The field of vision, moreover,
becomes gradually contracted, until only a very small central
portion remains ; so that, although the patient may still be able
to read, he cannot find his way alone — a function for which the
eccentric parts of the field are the important ones. A ring scotoma
in the field of vision is present in some cases. Finally, the last
remaining central region becomes blind.

PLATE VI

{To face page 328)

The pigment is arranged in a circle towards the periphery. Note the
stellate spots and the absence of patches of atrophy, and also the
pigment covering the vessels (cf. with Plate III., Fig. 2). The optic
disc is yellowish, the retinal vessels thread-like, and the chorioidal
vessels are visible all over the fundus owing to disappearance of the
pigment -epithelium. ""

Plate VI.

Retinitis Pigmentosa.

CHAP. XII.] THE RETINA. 329

The Ophthalmoscopic Appearances (Plate VI.) consist in a pig-
mentation of the nerve-fibre layer of the retina, which commences
in the periphery, but not at its extreme limits, and in the course of
years advances towards the macula lutea. The pigment is arranged
in stellate spots, of which the processes intercommunicate, so
that the appearance reminds one of a drawing of the Haversian
system of bone. Pigment is also deposited along the course of many
of the vessels, hiding them from view. The degree of pigmentation
varies much, and in some cases is quite absent, and the diagnosis
then has to depend upon the other appearances and on the symptoms.
The papilla is of a greyish-yellow colour, never white, and the vessels
are very small, and in the majority of cases the chorioidal vessels
are visible owing to disappearance of the pigment - epithelium
(Plate YI.).

The chorioid is sometimes slightly affected, irregularity in its
pigmentation being observable. At the posterior pole of the
crystalline lens there is often a star-shaped opacity (p. 272). A few
thread-like opacities may be found in the vitreous humour.

Pathology. — The pigment in the retina is beheved to wander into it
from the pigment-epithehum layer. The nervous elements of the retina
become atrophied and the pigment displaced. The other pathological
changes in the retina consist in hyperplasy of its connective tissue elements,
and thickening of the walls of the vessels at the expense of their lumen.
The retina also becomes adherent to the chorioid.

The chorioidal vessels, too, are altered, owing to endarteritis, which
causes hypertrophy of their coats, with more or less obliteration of their
lumen. In fact, it seems probable that the primary seat of the diseased
process is in the chorioid ; and that it is the changes in it which cause
the pigment from the pigment-epithelium layer to wander into the retina.

Causes. — Retinitis pigmentosa often affects more than one
member of a family and is hereditary ; and the patients, too, are
frequently defective in intelligence, or deaf and dumb. Many of
them are the offspring of marriages of consanguinity, and in others
an inherited syphilitic taint is present, while in others no cause can
be assigned. Other congenital defects, supernumerary digits, etc.,
are sometimes present.

Treatment is of little use. At best one may stimulate the torpid
retina temporarily by hypodermic injections of strychnia, or by the
continuous current. When there is an opacity at the posterior

330 DISEASES OF THE EYE. [chap. xii.

pole of the lens, although it may be of only slight degree, a remark-
able improvement in vision can be effected by extraction of the
lens.

Retinitis Punctata Albsscens. — This disease commences in early child-
hood, or is perhaps congenital. It often occurs in more than one member
of a family, and the parents are frequently blood-relations. The main
symptom is night-blindness ; in good daylight central vision is usually
not defective to any marked degree. The field of vision is contracted.
Ophthalmoscopically, the fundus, with the exception of the macula lutea
and its immediate neighbourhood, is sprinkled over with innumerable
small white dots, which, for the most part, are free from any pigmentary
disturbance in their neighbourhood. In some cases, towards the periphery
of the fundus, signs of chorioidal atrophy are present, or, there may be
pigment in the retina there. The retinal vessels and the optic papilla
are unchanged. It is thought by some that this disease is related to
retinitis pigmentosa.

Treatment is of no avail.

Gyrate Atrophy of the Retina and Chorioid. — This disease, which is
rare, is apt to occur in more than one member of the same family, and in
children whose parents are blood-relations. The first symptom appears
in childhood as night-blindness. The optic papilla is atrophied, as in
retinitis pigmentosa, and atrophy of the retina is shown by the narrowing
of its vessels. The characteristic feature is the peculiar form of chorioidal
atrophy. In a zone with the papilla for its centre, and extending
nearly to the latter, white atrophic dots with sharp margins form, and
gradually increase in size, until they become confluent. The atrophy
involves both the pigment epithelium and the stroma of the chorioid.
The papilla is finally surrounded by a broad white girdle, from which
it is separated by a band of normally coloured fundus. The edge
of the girdle towards the papilla is scalloped, because the separate
rounded parts of which it is composed extend backwards in varying
distances, while the remains of the normal fundus project forwards
between them in sharp processes. There is often, as in retinitis pigmentosa,
a star-shaped posterior polar cataract. In addition to the night-blind-
ness, central vision is much lowered, even in good light, and the field of
vision is much contracted. This disease, too, is closely related to retinitis
pigmentosa.

Quinine Amaurosis. — Quinine in large doses, and very occasion-
ally in small doses, is liable in some individuals to cause amblyopia,
which may come on almost suddenly, and may amount to absolute
blindness, accompanied for some hours or days by great deafness.
This absolute blindness is rarely more than temporary, although
it may last for some weeks ; but, in severe cases, concentric con-
traction of the field is apt to remain permanently, with or without

019111 .'lUoiOD iU

PLATE VII.
{To face page 330.)

FiQ^ 1. — Note the pallor of the optic disc, the thread-like arteries, the
' cherry-red spot ' at the macula lutea, and the surrounding cloudiness
of the retina.

Fig. 2. — The inferior retinal vein is engorged and tortuous, and darker
in colour. There is slight cloudy oedema of the retina, and numerous
flame-shaped and blotchy haemorrhages ; in the centre of one large
haemorrhage are some white spots due to absorption, or to fatty de-
generation.

Plate VII.

Fig. 1. Embolism of Central Artery of Retina.

Fig. 2. Thrombosis of Inferior Retinal Vein.

CHAP. xiT.] THE RETINA. 331

some defect of central vision. In a serious case which came under
our notice, the colour and light-senses, notwithstanding the con-
tracted field and marked seeming optic atrophy, were normal ; but
the adaptation of the retina, as shown by considerable night-
blindness, was defective.

Yarr finds that doses of sulphate of quinine of more than 20
grains are dangerous to the sight, and that more than 40 grains
should not be given in twenty-four hours. During the early stages,
the pupils are widely dilated, and the cornea and conjunctiva are
sometimes anaesthetic.

In what may be called the acute stage, the Ophthalmoscopic
Appearances are sometimes normal, but pallor of the optic papilla,
with scarcity and smallness of the retinal vessels, is the more usual
condition. Where the case is chronic— the fields remaining con-
tracted, although central vision has improved — the ophthalmoscope
may reveal a very pale optic papilla with minimal vessels.

The retinal ischeemia is doubtless the immediate Cause of the
amblyopia, and is the result of diminished heart's action and lowered
arterial tension, both of which have been shown to be produced
by large doses of quinine. Destruction of the ganglion cells of the
retina towards its periphery has been found, and to it may be
referred the permanent contraction of the field of vision in some cases.

Treatment. — Cessation of the use of quinine. Digitalis internally
to raise the arterial tension, nitro-giycerine, hypodermic injections
of strychnia, and general tonic treatment. Nitrite of amyl causes
only temporary improvement of vision.

Amaurosis from Filix Mas. — In the rare cases of this kind due to large
doses (3i to ij) of extract of male fern, the blindness is usually preceded
by headache, vertigo, tinnitus, prostration, diarrhoea, and coma or con-
vulsions : sometimes, too, by pain at the back of the eye and on movement.
Ophthalmoscopically, great diminution in calibre of the retinal arteries
with congestion of the veins, and extreme oedema of the retina, seem to
be the initial appearances, followed at a later period by atrophy of the
optic nerve. In severe cases vision does not return.

Injury of the Retina by Strong Light.

Blinding of the Retina by Direct Sunlight. — This is especially
likely to occur on the occasion of solar eclipses, by observation
without proper protection of the eyes.

Immediately after the exposure, the patients complain of a

332 DISEASES OF THE EYE. [chap. xii.

dark or semi-blind spot in the centre of the field of vision — a posi-
tive scotoma, in short, which may even be absolute, and which
interferes with vision in proportion to the length of the exposure.
There may also be a central defect for colours, which may extend
over a larger area. A peculiar oscillation, or rotatory movement,
is frequently observed by the patient in the scotoma, and is very
persistent. Objects may also seem twisted or otherwise distorted
(metamorphopsia) .

The Ophthalmoscopic Appearances may be normal, but as a rule
some changes exist, such as irregularity or indefiniteness of the light
reflex at the macula, with reddish-brown discoloration around the
foveal area, or a minute pale orange spot near the fovea, and, especi-
ally in the later stages, some darkening or pigmentation. When
the cases are not severe, improvement in vision takes place, but
complete recovery is not common. Hitherto no case in which the
vision had been reduced to less than J has regained good sight.

Treatment. — Hypodermic injections of strychnia, the constant
galvanic current, dry cupping on the temple, and sub-conjunctival
saline injections, afiord the best chances for promoting the cure.
Rest and dark protection glasses are important.

Snow-Blindness. — Exposure of the unprotected eyes for a
length of time to the glare from an extensive surface of snow pro-
duces, in some persons, a peculiar form of ophthalmia, which may
be followed by temporary or even permanent amblyopia. Although
this condition is chiefly an affection of the conjunctiva, it is de-
scribed here in order to contrast it with the effects of direct sunlight
and electric light.

Snow-Blindness begins with sensations of a foreign body in
the eye, photophobia, blepharospasm, and lacrimation ; later on
chemosis, with small opacities, or ulcers, of the cornea, comes on.
The condition passes off in three or four days without leaving any
pernianent ill results, except in rare cases, when there may be some
secondary hyper.Tmia of the retina. It is held to be the ultra-
violet-rays which cause snow-blindness.

Treatment. — The preventive treatment consists in the wearing
of dark smoked, yellow, or, best of all, euphos glasses when travel-
ling on the snow ; while, for the ophthalmia and to relieve the dis-
tressing symptoms, cold applications and cocaine with adrenaline
are recommended.

CHAP. xti.J THE RETINA. 3^^

Effects of Electric Light on the Eyes. — The degree of intensity
of electric light required to produce injurious effects on the eye is
not known ; but no bad results Jiave been observed from the
ordinary use of the incandescent electric light, for reading, writing,
etc. ; on the contrary, it may be regarded as the best artificial light
for these and other domestic uses. It has a greater illuminating
power, produces less heat and no products of combustion, and
hence it does not vitiate the atmosphere, nor tend to cause con-
junctival irritation. The electric light is steadier than gas ; and,
on account of the smaller quantity of red rays it contains, it more
nearly approaches da3dight than does gas, unless the latter be used
with the incandescent mantle. It should, however, be so arranged
for use that the rays may not enter the eye directly, or discomfort
in the form of smarting, burning, and headache may result, by
reason of its being rather rich in ultra-violet rays. Two groups
of symptoms are observed from the action of strong electric light
on the eyes : —

(«) Electric Ofhthalmia. This has been chiefly seen in those
employed in electric welding operations, and less frequently in
electricians who use strong arc-light. The symptoms begin shortly
after exposure to the light, always within twenty-four hours, and
are the same as those present in snow-blindness ; the lids also are
swollen, and even erythematous at times. The pupils are contracted.
A slight muco-purulent secretion from the conjunctiva, rich in
eosinophil cells, appears after the subsidence of the above symptoms.
Recovery takes place in a few days, with complete restoration of
vision, except in rare cases.

(6) Blinding of the Retina by Electric Light.— This is the same
affection as the blinding of the retina by direct sunlight. The
central scotoma may persist after an attack of electric ophthalmia,
or may occur without it. The injurious action of the electric light
on the eye is attributable to the chemical action of the ultra-violet
rays. Widmark's experiments show that changes can be produced
in the retina by the electric light, without any heat coagulation.
These changes consist in oedema, with more or less destruction
of the nervous elements of the retina — namely, the outer layers,
including the rods and cones, and the inner layer of nerve-fires.

Treatment. — The preventive treatment consists in the use of
coloured glasses. Yellow glass has been recommended by Mak-

f}34 DISEASES OF THE EYE. [chap. xi±.

lakoff, and the new euphos glass, a peculiar shade of yellow, is
also in use. The object of this glass is to cut oft" the ultra-violet
rays.

For further effects of light on the eyes, see also glass- workers'
cataract and erythropsia.

Tumour of the Retina.

Glioma of the Retina. — This is a malignant growth and is
found almost exclusively in young children, or may even be con-
genital, and occasionally occurs in several children of the same family.
It is sometimes present in both eyes. Owing to the age of the
patients, the incipient stages of the disease are seldom observed,
for they are unattended by pain or inflammation, and the children
are not brought to the surgeon until the parents notice that the
sight is very defective, or until they see the white appearance in
the pupil.

The growth commences as small, \vhite, disseminated swellings
in the retina, usually in one or other of the granular layers, more
rarely in the nerve-fibre layer. The retina is apt to become detached
at an early period ; but there are exceptions to this, especially when
the disease starts from the nerve-fibre layer. Glioma may be en-
dophytic, growing inwards towards vitreous humour, or exophytic,
growing outwards towards chorioid. In the early stages there is
no iritis, cyclitis, or opacity of the vitreous humour, and the iris
periphery is not retracted — points which especially enable us to
distinguish it from pseudo-glioma (p. 298). Secondary glaucoma
finally comes on. The optic nerve may become involved at an
early period ; but" sooner or later it invariably does so, leading then
by extension to glioma of the brain. When the tumour has filled
the eyeball, it bursts outwards, usually at the corneo-scl erotic
margin, and then grows more rapidly, and often to an immense
size, as a fungus ha3matodes. The orbital tissues become involved,
and even the bony walls of the orbit ; while secondary growths
in other organs, more especially in the liver, are not rare.

The diagnosis between glioma of the retina and tubercle of the
chorioid (p. 221), when the latter occurs in young children, is some-
times difficult or impossible ; but, in view of treatment, it is not
of great importance, as in either case the eye must be enucleated.

CHAP. XII.] TiaiS RETINA. 335

The tumour consists of closely set small round cells with a large
nucleus and little protoplasm. There arc numerous vessels, scanty
intercellular substance, and areas of degeneration.

In glioma of the retina, as in sarcoma of the chorioid (p. 220),
phthisis bulbi with regressive metamorphosis of the new growth
may come on, and give the appearance, for a lengthened time, of
a cure of the tumour. But, probably invariably, renewed growth
of the tumour takes place.

Treatinent. — The only hope of saving the patient's life lies in
enucleation at an early stage, or before the optic nerve becomes
diseased. It is important in removing the eyeball, as in every
intra-ocular growth, to divide the nerve as far back as possible ;
and, if the orbital tissues be already diseased, to remove all
suspicious portions of them. Several cases in which there was no
return of the grow^th have been observed, even after removal of both
eyes ; and in a case of the latter kind under the care of one of us,
the patient continues healthy eight years after removal of the eyes.

Tubercle of the Retina. — Primary tubercle of the retina is exceedingly
rare, and presents the appearance of a more or less extensive and slightly
elevated white area, at the posterior pole of the eye, involving the optic
disc or macula lutea or both. When the disease occurs in a young child,
the diagnosis from glioma of the retina will present difficulty. Or, there
is in the region of the posterior pole a large yellowish-white mass spreading
out in all directions from a detached and non-translucent area of retina,
while towards the periphery there are multiple haemorrhages and yellowish
deposits of various sizes ; the optic papilla and retinal vessels being normal.
More commonly, tubercular disease of the retina is secondary to tuber-
culosis of the uveal tract, or optic nerve.

Treatment. — Tuberculin (p. 18-1).

Paeasitic Disease.

Cysticercus under the Retina. — The cysticercus of the tsenia solium
in the eye is very rare. Its most frequent seat is between the retina and
chorioid, where it is recognised with the ophthalmoscope as a sharply
defined bluish-white body, with bright orange margin. At one point of
the cyst there is a very bright spot, which corresponds with the head of
the entozoon. Wave-like motions along the contour of the cyst should
be looked for to corLfirm the diagnosis. The cysticercus may move from
its original position, and in so doing cause considerable detachment of the
retina. Delicate veil-like opacities are apt to form in the vitreous humour,
and are almost characteristic of the presence of cysticercus.

The entozoon may become encapsuled behind the retina ; or it may

336 DISEASES OF THE EYE. [chap. ±u.

burst into the vitreous humour (p. 312) ; and finally chronic irido-cyclitis,
with total loss of sight and phthisis buibi, is apt to come on.

Treatment. — There is no authehnintic which will act upon the entozoon
in the eye. Removal of the cyst by operation is the only means by which
the eye can be saved ; and this measure can only be resorted to w^hen
the position of the cysticercus is favourable — e.g. when it is close to the
equator of the eyeball. In such cases, by a well-placed puncture through
the sclerotic and chorioid, the entozoon may be evacuated. If this cannot
be accomplished, the eye must be excised.

Detachment of the Retina.

The normal retina is firmly attached at the optic disc and at the
ora serrata only. Between these it adheres merely by prolongations
of the pigment epithelium, which run between the rods and cones,
and hence, under certain conditions, it readily becomes detached
or separated from the chorioid. Even when there is ' total detach-
ment ' of the retina, it remains adherent at the optic disc and ora
serrata. In detachment of the retina the space between retina
and chorioid is occupied by a clear serous fluid. It is not usual to
employ the term, when it is a solid neoplasm only that lies between
retina and chorioid.

If the media be clear, and the detached portion extensive, the
diagnosis is not difficult.

The Ophthalmoscope (Plate V. Fig. 2) shows a greyish reflex from
a position which is anterior to the fundus oculi, and to the surface
from which the greyish reflex is obtained a wave-like motion is
imparted when the eyeball is moved. Over this greyish surface
the retinal vessels run, and they serve to distinguish a detached
retina from any other diseased condition with a somewhat similar
appearance. The vessels seem black, not red, in consequence of
absorption of the light reflected back from the fundus, and they
are hidden from view here and there in the folds of the detached
retina. The detachment renders these parts of the fundus hyper-
metropic. In many cases a rent in the detached retina, usually
towards the ora serrata, through which the chorioid can be dis-
cerned, will be discovered. In some cases the detached part retains
its transparency, and does not become grey or opaque ; and then
it is the reflexes from the folds of the detachment, the dark retinal
vessels, and the fact that both folds and vessels lie in front of the
true fundus oculi, which enable the diagnosis to be made.

CHAP. XTi.] THE RETINA. 337

The detachment may commence in any portion of the fundus,
but most commonly does so above ; yet, owing to gravitation of
the fluid, it ultimately settles in the lower half of the fundus, and
hence this is the most common place to find it, the part first detached
having become replaced. The diagnosis is more difficult if there be
but little fluid behind the retina, or if there be opacities in the vitreous
humour.

Vision is affected according to the position and extent of tlie
detachment. Central vision may be quite normal if the macula
lutea and its immediate neighbourhood be intact. The patients
complain of distortion of objects looked at, of a black veil or curtain
which seems to hang over the sight, and sometimes of black floating
spots before the eye, due to opacities in the vitreous humour. These
symptoms often come on suddenly in an eye which has hitherto
had good sight.

The field of vision, on examination, will show a defect which
corresponds with the position of the detachment. If, for example,
the detachment be below, the defect will be in the upper part of
the field. If the detachment be recent, the retina not having yet
undergone secondary changes, and if the quantity of subretinal
fluid be not great, the defect in the field may only amount to an
indistinctness of vision ; while later on, when — owing to derange-
ment of its nutrition from its being separated from the chorioidal
capillaries — infiltration and degeneration of the detached part
come about, fingers may not be counted in the defective area of
the field. Blue blindness is sometimes present.

Should the detachment become complete, little more than mere
power of perception of light may be present. Total detachment
is followed by cataract, and often by iritis, cyclitis, and phthisis
bulbi. The detachment may remain stationary, and may not
extend to the whole fundus, or the retina may return to its normal
position ; but this latter event is most rare. For the diagnosis of
detachment of the retina from tumour of the chorioid see p. 218.

Causes. — Myopic eyes — which we know are so frequently affected
with chorioiditis and disease of the vitreous humour — are those
most subject to detachment of the retina (chap, xvi.) ; but idiopathic
detachment occurs also in eyes which are apparently healthy. Blows
upon the eye may produce detachment, the retro-retinal fluid being
serous or bloody ; and some punctured w^ounds of the sclerotic, in
22

338 DISEASES OF THE EYE. [chap, xii

the course of liealing, by dragging on the retina, give rise to it.
Chorioidal tumours, especially those situated in the posterior seg-
ment of the fundus, usually cause detachment in an early stage of
their growth, and the complication renders their diagnosis more
difficult. Other causes are exudative chorioiditis and rarely
Inemorrhage.

The pathology is still obscure. Leber observed that, in non- traumatic
detachment, a perforation or rent in the detached portion is very fre-
quently to be seen with the ophthalmoscope, and holds that it is probably
always present, although sometimes, from being hidden behind a fold of
the retina, it cannot always be found. From this, and from his patho-
logical investigations and experiments upon animals, he was led to the
opinion that the detachment was due to shrinking of a diseased vitreous,
which first became slightly separated from the retina, and that then — at
some place where the retina and hyaloid had become adherent by reason
of an inflammatory process — a rent was produced in the retina by the
shrinking process in the vitreous. He concluded that through this rent
the fluid, which is always present behind the vitreous in cases of detach-
ment of that body, makes its way behind the retina, and separates the
latter from the chorioid. The suddenness with which detachment often
comes on is accounted for by this theory. Nordenson's pathological
researches went to corroborate this. He ascertained, too, that disease
of the ciliary body and chorioid is the primary cause, although we may
not be always able to detect it with the ophthalmoscope, and that the
pathological change in the vitreous humour consists in an alteration in
its connective tissue elements, resulting in the deleterious shrinking.

Raehlmann, however, from the results of experiments, and also from
clinical observation, concludes that detachment of the retina is due to
exudation from the chorioidal vessels of a fluid, which is more albuminous
than the fluid in the vitreous humour. Hence, he thinks, diffusion takes
place through the retina, and a greater quantity of the less albuminous
vitreous fluid passes through the retina, thus producing and increasing
the detachment. Rupture of the retina is not, in his view, a necessary
factor in the causation, but it may occur if the tension behind the retina
be higher than that in front of it.

Treatment. — The dorsal position in bed, with a pressure bandage
on the eye, and diaphoretics internally, the treatment being con-
tinued for from four to six weeks, brings about reposition of the
detachment in some cases. To this treatment sub-conjunctival
injections of a 5 to 10 per cent, saline solution may be added. The
method, if properly carried out, is trying to the patient.

Evacuation of the subretinal fluid by puncture of the sclerotic
is employed. The instrument used resembles a broad needle, with
blunt edges, which is entered through the sclerotic and chorioid at

CHAP. xiT.] THE RETINA. 339

a place corresponding with the position of the detachment, but not
so deeply as to reaT5h the retina, lest thereby it be further displaced.
The instrument is then given a quarter of a rotation, to make the
wound gape, so as to admit of the flowing off of the fluid. If possible,
a position near the equator of the globe, and between two recti
muscles, should be selected for the operation. Moreover, the
incision should lie parallel to the direction of the muscles, so that
the chorioidal vessels may be injured as little as possible. A firm
dressing and bandage is applied, and the patient kept in bed for
eight or ten days. For the most part the cure is but temporary.

To promote adhesion between retina and chorioid. Dor touches
the sclerotic corresponding with the detachment lightly with a small
cautery, injects rather strong (10 per cent.) solutions of common
salt under the conjunctiva, and keeps the patient in bed. He
reports some cures by this method.

The cautery may be combined with puncture, or the puncture
may be made with the cautery.

Other operations are : — Transfixion of the globe through the de-
tachment with a cataract knife, a sort of double puncture. Excision
of a portion of sclera as far back as possible, or removal of a disc
with the trephine, have also been tried. The Prognosis of every
case of detached retina is bad, spontaneous cure being extremely
rare, and cures effected by any one or by any combination of methods
of treatment being few and far between ; while, even when the
retina returns to its place, there is the danger of a recurrence of the
detachment. Moreover, both eyes often become affected, one after
the other. It is important therefore to explain the prospects of the
treatment to the patient before it is commenced. The most favour-
able cases are those due to chorioiditis, the most unfavourable those
due to posterior staphyloma.

Traumatic Affections of the Retina.

In addition to detachment and rupture of the retina, the under-
mentioned conditions occur as the results of injuries.

Traumatic Anaesthesia of the Retina.— A blow on the eye
from a fist, cork from a bottle, etc., is liable to produce considerable
amblyopia, with concentric contraction of the field, which may
continue for a long time, while the Ophthalmoscopic Appearances

340 DISEASES OF THE EYE. [chap. xii.

are normal. Ultimately these cases usually recover, an event
which may be promoted l)y the use of strychnine hypodermically ;
but very defective sight sometimes remains perniiuieiitly.

Commotio Retinae, or Traumatic (Edema of the Retina, is the

result of a blow upon the eye. Immediately after the blow there
is marked episcleral injection, and the pupil can be dilated but
slowly with atropine. Within a few hours after the accident the
Ophthalmoscope reveals a white cloudiness (oedema) of a portion
of the retina, usually in the neighbourhood of the optic papilla
and macula, but sometimes more eccentrically ; and sometimes
there are two such opaque patches. The opacity increases in
intensity, and spreads somewhat. The retinal vessels remain
normal ; there may be some small haemorrhages, and sometimes the
papilla is redder than normal. These appearances completely
disappear in the course of a few days. Vision is only slightly
affected, and recovers as the retinal changes pass off.

' Holes ' at the Macula Lutea. (Retinitis atrophicans centralis, of
Kuhnt). — Blows on the eye sometimes give rise to a remarkable lesion at
the macula lutea. The ophthalmoscopic appearances suggest a punched-
out hole, generally of a circular or oval shape. This area is depressed
below the level of the surrounding retina, its floor is of a deep red colour,
and its margin is sharply defined, or it is surrounded by a light cloud
which fades off into the retina. On the floor of the hole and arouiid its
margin innumerable very fine glittering dots are present in many cases.
In some cases there is a shallow detachment of the retina, but in the
majority of them there is none. Contrary to what would be expected,
the functions of the macula lutea, although diminished, are not com-
pletely lost, and an absolute central scotoma is not present in every case.
Consequently, it must be concluded that, notwithstanding the apparent
serious damage, the delicate tissues at the macula lutea, and the nerve-
fibres connecting it with the optic nerve, are not always completely
destroyed.

Very similar appearances, without any history of trauma, have
been observed occasionally to follow iritis or irido-cyclitis. They have
also been seen in the eyes of elderly people the subjects of arterio-sclerosis,
and in albuminuric retinitis, retinitis pigmentosa, amaurotic family idiocy,
after perforating injuries, operations, or corneal ulcers, followed by in-
flammation. The pathogenesis of this condition has not been clearly made
out. (Edema, or cystic degeneration of the retina, followed by destruction
and absorption of the tissue at the macula is probably the cause of these
so-called ' holes.'

CHAPTER XIII.

DISEASES OF THE OPTIC NERVE.

The Optic Nerve may be affected, directly or indirectly, at various
parts of its course, from the optic commissure to its termination
in the eyeball. For clinical purposes it is convenient to distinguish
the following portions of the nerve ; the intra-cranial portion, the
optic canal portion, the intra-orbital portions behind and in front
of the entrance of the central artery of the retina into the nerve,
and lastly the termination of the nerve in the eye, known as the
optic papilla or optic disc.

Optic Neuritis. — The Ophthahnoscopic Appearances (Plate VIII.
Fig. 1) of inflammation of the optic nerve within the eye, vary a good
deal with the intensity of the process. Common to every case is
hypersemia and swelling of the papilla, with haziness (so-called
" woolliness ") and radial striation of its margins, and increase in
the size of the central vein, w^hile the central artery remains of normal
dimensions, or is contracted. The swelling and haziness extend
but a short distance into the surrounding retina, and the distension
of the vein is also not continued to the periphery of the fundus. In
slight cases, these appearances may barely exceed the normal.
They first appear at the upper and lower edges of the disc and the
inner margin becomes affected before the outer.

In extreme instances, the disc is swollen to a great size, and
may even assume quite a dome shape, while the veins are enor-
mously distended and tortuous, and the arteries are contracted so
as to become barely visible. (Plate VIII.) In some cases greyish
striae extend from the papilla into the surrounding retina, some
flame-shaped haemorrhages are present on or near the papilla, and,
occasionally, white spots in the retina, and a stellate arrangement
of small white dots about the macula lutea, form a picture which

341

342 DISEASES OF THE EYE. [chap. xiii.

cannot be distinguished from that of albuminuric retinitis (Plate V.
Fig. 1). This extreme form is still termed Congestion Papilla or
Choked Disc. It is also known as Papilloedema.

The Vision, even in cases where the ophthalmoscopic signs are
highly developed, is frequently normal ; while, again, in other, and
possibly less well-marked cases, it may be reduced to perception
of light, or even that may be wanting. When due to cerebral
tumour, the papilloedema appears, as a rule, before the vision becomes
affected. This remarkable disproportion between the degree of
blindness and the ophthalmoscopic appearances depends, probably,
on the extent to which the nervous elements of the optic nerve
are pressed on or altered, and this cannot be gauged by the ophthal-
moscopic appearances.

Sometimes the field of vision is normal, while again it is con-
centrically or irregularly contracted, or it may be hemianopic.
The blind spot is enlarged. In cases of choked disc the field for
colours is often reversed, as in hysteria, the field for red being
wider than that for blue (Fig. 12).

Attacks of temporary loss of sight are a common symptom in
cerebral tumours ; they may occur several times a day, and each
one may last from a few minutes to half-an-hour. By some these
attacks are held to be due to cramp of the retinal vessels, and., by
others, to sudden elevations of the intra-cranial pressure, or to
pressure of the infundibulum, but none of these explanations are
satisfactory.

Pathologically, the changes in the papilla consist in venous hyper-
£emia, oedema, hypertrophy of the nerve-fibres, infiltration of lymph
cells, and development of connective tissue. Inflammatory changes,
although less pronounced, are also present in the trunk of the nerve
and its sheaths.

Causes. — Inflammation of the optic nerve is most commonly
found in connection with coarse encephalic disease. A Cerebral
Tumour (including syphiloma, tubercle, cyst, and abscess) in par-
ticular is the most common cause, and is, moreover, usually present
when the papillitis is of an intense type (choked disc). Even a small
tumour situated anywhere in the brain is capable of producing optic
neuritis. The most intense papilloedema is seen in cases of cere-
bellar tumour. The papilloedema, except in very rare instances, is
bilateral, and it is one of the general symptoms of cerebral tumour.

PLATE VIII

{To face page 342)

Fig. 1. — The optic disc is greatly swollen and prominent as shown, more
especially, by the enlarged veins, which cm-ve over the surface, and
which are, in some places, lost to view under the edge of the swollen
disc. The congestion of the disc is somewhat diminished by exuda-
tion, and several flame-shaped haemorrhages are present. Tliis is
the type of optic neuritis which accompanies intra-cranial tumours.

Fig. 2. — The atrophy here has followed on the subsidence of optic neuritis
The disc is very white, ' filled in ' in the centre where the origin
of the vessels is partly hidden. The inner margin of the disc is
' woolly.' Note the white lines bordering the vessels, due to peri-
vasculitis. Some of the arteries are very narrow.

Fig. 3. — The disc is white and sharply defined, and the lamina cribrosa
is visible. The vessels had not diminished in size in this case, although
it is more usual to find them much reduced in calibre.

Plate VIII.

L.VV.

Fig. 1. Choked Disc.

L.W.

Fig. 2. Consecutive Atrophy of Optic Nerve.

L.W.

Fig. 3. Primary Atrophy of Optic Nerve.

CHAP. XIII.] THE OPTIC NERVE. 343

Hemianopsia may be present if the visual centre or fibres on one side
be involved. Cerebral cysts do not often cause choked disc.

With a view to operation it would be important to know whether
papilloedema has any locaHsing vahie. Can it afford any indication of
the side of the brain in which the tumour or lesion is situated ? The
differences of opinion which prevail with regard to this question are so
great that it is difficult to give a satisfactory answer, but this much may
be said : the retinal changes (haemorrhages, etc.) present along with the
swelling of the disc have no localising value, and the same applies to the
choked disc itself in the intracranial complications of otitis media, with
the exception perhaps of cerebral abscess ; further it may be stated that
cerebral abscesses and tumours of the cerebellum are more likely to be
found on the side of the more advanced papilloedema if it be bilateral, or
on the side of the papilloedema if it be unilateral.

Exophthalmos (apart from actual invasion of the orbit by a growth)
when it occurs with papilloedema, is more marked on the side of the intra-
cranial tumour, or is present on that side alone.

The Connection between Congestion Papilla and Intra-cranial
Tumours has given rise to much discussion, and many divergent
views are still held on the subject. In these cases a considerable
exudation of fluid usually takes place into the cavity of the third
ventricle. This, along with the new growth, increases the pressure
within the cranial cavity. By reason of this increased intra-cranial
pressure, the sub-arachnoid fluid is driven into the sub-vaginal
lymph-space of the optic nerve, and produces that dropsy of the
sheath which is found, in many cases, on careful post-mortem
examination.

It may be that the reason why some small cerebral tumours
cause papilloedema, while some large ones do not, is to be sought
in the fact that the former may happen to be rapidly growing
tumours, and to be accompanied by much ventricular dropsy,
while the larger tumours may be slow in growth, and attended by
but little dropsy of the ventricles.

Most authors now believe in the mechanical theory, according
to which increased intra-cranial pressure is the primary and essential
cause of choked disc in cases of intra-cranial tumour, and that
inflammatory changes, such as they are, are only secondary. (Edema
of the brain substance may also contribute to the increased pressure.

Choked disc occurs in about 80 per cent, of the cases of intra-
cranial tumour ; but it is not usually one of the very earliest signs,
headache^ nausea, etc., preceding it in the majority of cases. In

344 DISEASES OF THE EYE. [chap. xiii.

tumour of the cerebellum choked disc is commonly an earlier
symptom than it is in tumour of the cerebrum. Tumours of the
pons, medulla, and corpus callosum are those in which it is most
likely to be a late symptom. In the course of time, unless death
intervenes, the swelling of the discs, and other primary appearances,
subside, and complete atrophy of the optic nerves results (Plate
VIII. Fig 2) ; and even before this stage is reached the patient
will have become absolutely and permanently blind.

Treatment. — To avert blindness, even where the prospects of life
are not for long, and with the object of affording relief from the
racking headache, and other distressing symptoms, it has become a
recognised practice, to reduce the intra-cranial pressure by a pallia-
tive decompression operation. This is accomplished by trephining
the skull and opening the dura mater. It should be done as early
as possible in the case, and it is held by some to be indicated even
before choked disc appears, if the symptom of recurring attacks of
blindness be present. When there are no localising symptoms the
right temporo-parietal region is selected as the site of operation.
Some surgeons do not open the dura mater unless the symptoms are
not relieved, when they incise it at a later stage. After operation
the papilloedema subsides, sometimes very rapidly.

Causes. — Other intra-cranial causes besides tumours may- give
rise to papilloedema, for example cerebral abscess, fractures of the
skull, intra-cranial aneurisms, cerebral sinus thrombosis, subdural
haemorrhage, and cranial deformity (Tower skull).

Tubercular Meningitis is a common cause of optic neuritis.
Non-tubercular meningitis occasionally gives rise to it, and some-
times, also, cerebro-spinal meningitis.

Hydrocephalus. — Here the pathogenesis is probably the same as
in the foregoing ; but the occurrence of optic neuritis is not very
common with the hydrocephalus of children. It does occur with
the rarer hydrocephalus of adults, of which the symptoms may be
indistinguishable from those of intra-cranial tumour.

See also Diffuse Sclerosis of the Brain, chap. xiv.

Tumours of the Orbit. — How these growths bring about papillitis
is still unknown.

Inflammatory Processes in the Orbit, such as caries, inflamma-
tion of the retro-orbital areolar tissue, erysipelas of the head and
face extending to the orbital tissues, and periostitis. The presence

CHAP. XIII.] THE OPTIC NERVE. 345

of the latter may often be recognised by pain on motion of the
eyeball, pain in the eye and forehead, and especially by pain on
pressure of the globe backwards, and is frequently of rheumatic
origin. Often in these cases one eye only is affected ; and, although
the Ophthalmoscopic Appearances are sometimes very slight, yet
vision may be quite lost in a few hours or days, atrophy of the
nerve then rapidly setting in. Very many of the cases, however,
do not go on to atrophy, but end in recovery of useful vision.

Disease of the nasal sinuses usually with, but it may be without,
secondary involvement of the orbit sometimes causes optic neuritis.

Suppression of Menstruation. — If during the menstrual period
the flow be arrested by exposure to cold, wet feet, etc., acute optic
neuritis with rapid blindness may come on. Spontaneous amenor-
rhoea, or even irregularity of menstruation, and the climacteric period
are liable to have a similar but more chronic result. Nothing is
known with regard to the connection between the uterine and ocular
disorder. In these cases the Ophthalmoscopic Appearances, as
well as the blindness, are apt to be extreme. Treatment should be
directed chiefly to restoring, when possible, the normal uterine
functions. Hot foot-baths and Heurteloup's leech to the temples
are of use.

Chlorosis. — Here the optic neuritis is due to the disordered state
of the blood. The Ophthalmoscopic Appearances are usually slight,
but occasionally they are of extreme degree, and resemble choked
disc. These latter cases may be taken for cerebral tumour by
reason of concomitant symptoms — headache, vertigo, vomiting,
retraction of the head, stupor or delirium ; and convulsions. Ocular
paralysis may also occur especially involving the sixth nerves.
These symptoms are probably due to intracranial thrombosis. The
neuritis yields under the influence of iron and arsenic.

Syphilis. — The trunk of one or both optic nerves may be the
seat of specific inflammation in connection either with congenital
or with acquired syphilis, but this primary specific optic neuritis
is a relatively rare disease. In cases of acquired syphilis it makes
its appearance in from six months to two years after the primary
infection. The Ophthalmoscopic Appearances may be normal
(retro-bulbar neuritis), or may present any grade of neuritis, even
to the most pronounced papillitis. In the latter case it would not
be possible to say whether the papillitis is a primary one, or is due

346 DISEASES OF THE EYE. [chap. xiii.

to a syphilitic gumma within the cranium. The inflammation often
extends as far up as the chiasma. The Treatment in these cases
of specific papillitis must be active mercurialisation. By this means,
even if perception of light be lost for a period of not more than
eight to fourteen days, hopes may be entertained of its complete
or partial recovery. Cases of double optic neuritis of syphilitic
origin have been observed, in which complete recovery took place,
the papilla returning to its normal condition. But, as a rule, some
optic atrophy, at the least, with slight concentric contraction of the
field, results. The prognosis is all the better the sooner the optic
neuritis follows upon the primary syphilitic affection.

Lead-Poisoning, — In some cases of lead-poisioning optic neuritis,
not to be distinguished from that of primary cerebral affections,
is found. Sometimes the Ophthalmoscopic Appearances are slight,
and, again, quite pronounced, the changes extending into the retina.
They sometimes simulate the retinitis of Bright' s disease ; and in
such cases renal disease is likely to have much to do with the causa-
tion of the retinitis. Some authorities, who have good opportunities
for forming a correct opinion, deny the existence of a specific lead
neuritis, and hold that the neuritic affection in all such cases is to
be referred to albuminuria, or to efiusion into the ventricles of the
brain and subarachnoid space, or to accompanying suppression of
menstruation. Occasionally optic atrophy is the first ophthal-
moscopic appearance seen ; but it is probably consecutive to retro-
bulbar neuritis, as shown by white striae (perivasculitis) along the
vessels. The Vision is often much affected, and it is stated that
sudden complete blindness, or hemianopsia, in connection with an
intercurrent attack of lead colic may appear and pass off again.
Consecutive atrophy is liable to come on, and then vision may be
seriously and permanently damaged.

As headache, vomiting, and convulsions are symptoms of the
more serious cases of lead-poisoning, it is evident that when intense
optic neuritis is added, the diagnosis between this disease and
cerebral tumour may be mistaken. The blue line on the gums,
and other characteristic signs of lead-poisoning, will prevent such
an error. The Treatment is that for general lead-poisoning, or for
the immediate cause of the neuritis.

In Peripheral Neuritis optic neuritis is occasionally found.

Disseminated Sclerosis. — In these cases the inflammation is

CHAP. XIII.] THE OPTIC NERVE. 347

very ephemeral, and rapidly gives place to atrophy. UhthofE states
that it occurs in about 13 per cent, of the cases of this disease.

Tabes Dorsalis. — A few cases of this disease are published in
which optic neuritis was present. It is probable that the latter
depended on co-existent syphilitic cerebral disease, rather than on
the spinal disorder as such. In Acute Myelitis, inflammation of the
optic nerve is sometimes seen, so that optic neuritis with paralytic
phenomena does not exclusively indicate cerebral disease.

Hereditary and Congenital Predisposition. — The disease known as
Hereditary Optic Neuritis, as Hereditary Optic Atrophy, and as Leber's
Disease, commences with sudden and marked loss of sight, the vision falling
perhaps to finger counting at 1 to 4 m. Both eyes are always attacked,
with an interval of from a few days to two years. The fundus is at first
normal, or slight optic neuritis is present. After a few weeks the papilla
becomes pale, especially in its temporal half, and gradually the typical
appearance of optic atrophy is developed. Examination of the field of
vision shows the presence of a relative or of an absolute central scotoma.
The periphery of the field is normal, or but slightly contracted. The
disease develops as a rule a few years after puberty — about the twentieth
year. The course and conclusion of the disease is not the same in every
instance. Most commonly the acuteness of vision and the central scotoma
remain stationary, but in some cases an improvement, falling short of
complete recovery of sight, has been noted, while in others complete
blindness came on. In the same family the course of blindness is apt
to be the same. Grosser derangements of the nervous system, such as
epilepsy, mental derangements, etc., do not commonly accompany this
eye-disease, but the lighter forms, as migraine, vertigo, palpitation of the
heart, are often observed. The hereditary transmission usually occurs
through the female members of the family to their male children, the
females themselves being rarely affected, while several or all of the sons
may be attacked. Treatment is, practically, of no avail. Mercury,
iodide of potash, strychnine, and galvanism of the sympathetic have been
employed. This disease is really a retrobulbar neuritis (see below).

Optic Neuritis also occurs occasionally in fevers ; it has been
observed in Measles, Scarlatina, Typhoid, and Malaria. It may
follow Influenza, causing contraction of the field of vision or central
scotoma which usually disappear, but may lead to optic atrophy.

In some cases, usually with high degrees of hypermetropia, the papilla
is normally red, somewhat prominent, and its margins are indistinct and
striated. The condition is known as Pseudoneuritis and is stationary.

Retro-Bulbar or Axial Optic Neuritis.— This is ushered in by
rapid, although never sudden, loss of sight in one eye, sometimes in

348

DISEASES OF THE EYE.

[CHAP. XIII.

temp.

both, or tliey may be attacked with a considerable interval between.
Examination of the field of vision discovers a central colour scotoma,
or one for white (Fig. 113), which is often absolute, and which is some-
times surrounded by a still wider scotoma for colours, and there is
impaired pupil-reaction to light. The patient sees less well in a very
bright light. At the commencement, pain in the orbit is complained
of, the motions of the eye are somewhat painful, and there is pain on
moderate pressure of the globe backwards into the orbit. Often

at first there are no oph-
Left Field thalmoscopic changes,

but after a time marked
optic neuritis shows it-
self, and this may pass
into atrophy, or atrophy
may appear without any
previous neuritis which
can be discerned. It is
rare for complete and
absolute amaurosis to
result, although the op-
tic disc remains white.
In most instances the
central scotoma dis-
appears, and almost nor-
mal vision is soon re-
stored ; but in some a
more or less well-marked
central scotoma, with
defective sight, remains.
It is frequently im-
possible to assign a cause
for this affection. Exposure to severe blasts of cold wind on
the head, rheumatism, and influenza are often blamed for it.
But it is not rarely an early symptom of disseminated sclerosis,
and from this point of view it must be regarded with suspicion
when it occurs in persons of between twenty and forty years of
age. It is also found associated with inflammatory processes in
the sphenoidal or ethmoidal sinus. (See also Toxic Amblyopia,
p. 349.)

Fig. 1 1 3, — Case of Retro-hulhar Neuritis in
Left Eye. Relative central scotoma for white.
Central V = finger counting at 1 metre.
Movements of eye somewhat painful. Pres-
sure backwards on eyeball caused pain.
Slight cloudiness of margin of disc. Caused
by chill through exposure to cold fog when
heated. Almost complete recovery of V. after
nine months. Some pallor of disc remained.
Right eye normal throughout.

CHAP, xni.] THE OPTIC NERVE. 340

Treatment. — Iodide of potassium in large doses and salicylate

of soda. •

Optic Neuritis associated with Persistent Cerebro-Spinal Rhinorrhoea. —

A good inany cases of piu-sistciit dropping of a watery fluid from the
nostril have been recorded, and in a considerable proportion of thcni the
eyesight was much affected, owing to optic neuritis or consecutive atrophy.
More or less severe cerebral symptoms are usually also present, such as
violent headache, epileptic attacks, vomiting, stupidity, drowsiness,
unconsciousness, delirium, and weakness of the lower extremities. The
severity of the head symptoms varies very much in different cases. Head-
ache is the most constant of these symptoms, but even it may be absent.
In one case there was loss of smell, and in another palpitation of the heart
with prominence of the eyes. The fluid which runs from the nostrils is
identical in its analysis with that of the cerebro-spinal fluid. The cerebral
symptoms are usually brought on, or increased in violence, if the fluid
should occasionally cease to flow. Leber's case proved to be one of
internal hydrocephalus, and the others were probably of similar nature.
He thinks the fluid comes from the third ventricle through a small opening
in the ethmoid bone, or the fluid possibly passed from the sub-dural space
along the lymph-spaces which surround the olfactory nerves.

The affection usually commences in early adult life, and no rational
treatment has been suggested. The flow may cease spontaneously for
periods varying from a few hours to several months. In some cases it
ceased altogether, or at least had not recurred after five or even fourteen
years. Most of the cases were lost sight of, but some are recorded as having
died of meningitis.

Toxic Amblyopia (Axial Neuritis). — Sijmftoms. — The defect of
vision comes on rather rapidly. The patients often complain of a
shimmering mist which covers all objects, especially in a bright light,
and generally state they can see better in the dusk than in broad
daylight. At the commencement there is general dimness of vision
but no defect in the field. At a later stage, examination of the
field discovers no defect for a white object ; but, if a small pale
green object be employed, it usually will be ascertained that, at
a region close to the point of fixation, the colour is not recognised,
but seems grey or white ; pink may seem blue, and red may appear
brown or black. This is a central colour-scotoma (Fig. 16), and
when it is very small it is easily overlooked in the examination,
unless a very small test object be used. As the disease advances,
a white object will be but indistinctly seen in the scotoma ; and in
some rare cases all power of perception within its area may be lost,
even the flame of a candle not being recognised. The scotoma is
usually of an oval shape, with its long axis horizontal, and it extends

350

DISEASES OF THE EYE.

[chap. xiii.

from the fixation point towards the blind-spot. Occasionally it is
of much larger dimensions, and sometimes surrounds the fixation
point (Fig. 114). The peripheral boundaries of the field of vision
remain normal, both for colours and for white.

Even when the scotoma is very pronounced it remains negative
— i.e. it is not observed by the patient as a dark spot in the field,
as is a scotoma due to disease in the outer retinal layers. The
affection is almost always binocular, and as a rule there is but little
difference between the vision of the two eyes.

The Progress of the disease is slow, occupying weeks or months.

Fig. 114. — Case of Toxic Amblyopia. Central (pericentric) relative
scotoma for white in each eye. V. in R.E. fingers at 2*0 m. ; in L.E.
fingers at 5*5 m. Pipe, 1 oz. strong tobacco per diem, and drank much
whisky. Outei third of each disc too pale. By abstention from tobacco
and alcohol, with strychnine and phosphorus internally, ahiiost complete
recovery in four months.

Restoration of normal vision usually takes place if the defect of
vision, although of extreme degree, be not of old standing. In
the latter case these patients, although incapacitated from reading,
writing, and other fine work, do not lose their power of guiding
themselves, as the functions of the periphery of the field are
maintained.

Causes. — With but few exceptions the subjects of this disease
are men, and the most common cause is excess in the use of alcohol,
or of tobacco, or of both. The kind of alcoholic indulgence most
likely to develop the disease is the frequent drinking of small doses

CH.\P. XIII.] THE OPTIC NERVE. 351

of the stimulant. The individual who often gets thoroughly in-
toxicated, and between times drinks but little, is less liable to con-
tract central amblyopia than he who, although never incapable
of transacting his business, takes many half-glasses of whisky or
brandy during the day. Dyspepsia and loss of appetite are con-
stantly present in these cases. Other signs of chronic alcoholism
need not be present, but one often sees trembling of the hand
and head, sleeplessness, and even delirium tremens. The kind of
tobacco most likely, when used in excess, to give rise to central
amblyopia is shag or twist. Other kinds of pipe-tobacco and
cigars may cause it, but we have not known of a case due to
cigarette- smoking.

Excess in alcohol is usually combined with excessive smoking,
usually over two ounces of strong tobacco in the week ; but cases of
pure alcohol-amblyopia certainly do occur — although some authors
deny it — as well as pure tobacco-amblyopia. The most common
age for tobacco-amblyopia is from thirty-five to fifty — a time of
life when men do well to give up, or to reduce very much, their use
of tobacco, as well as of alcohol.

Toxic amblyopia has also been observed in diabetes, syphilis,
nasal sinus disease, influenza, and some other febrile affections, and
in severe burns of the skin, in poisoning from bisulphide of carbon,
largely used in the manufacture of india-rubber ; from dinitro-
benzol, used for explosives ; and in poisoning with iodoform, stra-
monium, cannabis indica, opium, salicylic acid, filix mas, arsenic,
and lead.

The Ophthahnoscopic Appearances in the beginning are usually
quite normal. It is rarely that there is slight hypersemia of the
papilla and retinal vessels ; or, in addition, slight indistinctness of
the margins of the papilla, and sometimes white striae along the
vessels, especially before they leave the papilla. All the primary
appearances, if any be present, soon pass away, and give place to
a greyish whiteness of the temporal side of the papilla, while the
nasal portion remains of normal appearance, as do also the vessels.
At a very advanced stage, in some cases, the whole papilla presents
the appearance of white atrophy.

The Pathological Changes, in the optic nerve, consist of an in-
terstitial neuritis at its axis, commencing so high up as the optic
foramen, and gradually leading to proliferation of connective tissue

352 DISEASES OF THE EYE. [chap. xiii.

and to secondary descending atrophy of one bundle of fibres in the
optic* nerve. These are the papillo-mjicular fibi'es wliich specially
supply the region of the macula hitea, and which are exceedingly
vulnerable to the inlluence of certain toxic agents. The changes
may be regarded as analogous to those which take place in the
liver and brain as the result of chronic alcoholism.

Treatment consists, above all, in total abstinence from the poison
in question ; partial abstention is of little or no avail. If the
patients act up to their good intentions in this respect, improve-
ment rapidly takes place in most cases w4iich are not too far
advanced without any other treatment ; but the cure may be pro-
moted by the use of iodide of potassium in large doses, Heurteloup's
artificial leech or dry cupping to the temples, hot foot-baths, and
Turkish baths. Strychnine hypodermically (y\^ grain daily) in the
temple is often of use, and phosphorus and strychnine may be given
internally. Whatever remedy be used internally, care should be
taken that it does not produce or increase dyspepsia ; and it may
be necessary to restrict the internal medicine for a time, or alto-
gether, to a stomachic tonic, w4th abundant drinking of hot water.
Sleeplessness should be combated wath sulphonal, or bromide of
potassium. Treatment may have to be continued for some weeks,
before a cure can be noted.

A yet more serious blindness than that from ethyl alcohol or tobacco
is caused by drinking methylated spirit, or by inhaling its fumes. This
toxic amblyopia is much more common in the United States than else-
where, for a peculiarly dangerous form of methylated spirit is on sale
there for many trade purposes. It is known as wood alcohol, or Columbia
spirit, and contains 95 per cent, of methyl alcohol. The symptoms after
a debauch have been weak heart action, nausea, sweating, intense head-
ache, vertigo, delirium, and coma. Some twenty-four hours later dim-
ness of vision in each eye comes on, and passes rapidly into absolute
blindness. The attack of blindness is accompanied by pain on movement
of the eyes and on pressure of the eyeball backwards, symptoms which
would tend to place the condition in the category of retro-bulbar neuritis.
The pupils are dilated, and the liglit-reflex is absent. A characteristic
feature is that partial restoration of vision soon takes place, to be followed,
in the course of a few days or weeks, by more or less complete and per-
manent blindness. In the early stages there is optic neuritis, which is
followed by optic atrophy. As regards the field of vision, there is an
absolute central scotoma, and, moreover, the field is nearly always con-
tracted. In many of the cases death has occurred within a few hours
after the poisonous dose has been taken. There also have been recoveries
of sight as well as of health.

CHAP. XIII.] THE OPTIC NERVE. 353

Atrophy of the Optic Nerve. — This disease may be secondary
to some other optic nerve or retinal affection, or it may be a pri-
mary disease. The Vision is seriously affected, and complete blind-
ness is the usual result. With the Ophthalmoscope three varieties of
atrophy may be distinguished, namely : —

(a) Simple Atrophy (Plate VIII. Fig. 3), which is most often a
primary affection associated with disease of the nervous system
such as locomotor ataxy or disseminated sclerosis, but may be
secondary to pressure on the nerve fibres in any part of their course
below the external geniculate bodies. The optic disc loses its delicate
pink colour, becomes greyish or white, its margin becomes more
defined, it becomes flatter or even slightly cupped, and the vessels
in some cases are greatly reduced in calibre. Atrophy of this type
is also caused by retrobulbar neuritis, embolism of the central
artery of the retina, blindness from poisons (quinine, arsenic), severe
haemorrhages from stomach, etc. In glaucoma too simple atrophy
occurs.

(b) In Consecutive Atrophy following optic neuritis (Plate VIII.
Fig. 2) the ophthalmoscopic appearances consist in a white or greyish-
white papilla, with very diminished retinal vessels ; along the sides
of the vessels are white lines, which sometimes even obscure the
vessels, and which are due to hypertrophy of their coats. The
diminution in calibre of the vessel is a sign of neuritic atrophy, but
is not always present, and is found moreover with other forms of
atrophy. Other signs are a certain opacity of the papilla, with
filling in of the centre of the disc and concealment of the lamina
cribrosa, owing to development of connective tissue. The veins
are generally somewhat enlarged and tortuous. But many of
these signs tend to pass away, and after a time it may not be
possible to distinguish a post-neuritic from a primary atrophy.

When the optic disc begins to undergo atrophic changes, the
temporal half is the first to lose its colour and in some cases the
whiteness remains confined to the outer half (toxic amblyopia). In
making a diagnosis of atrophy it should also be remembered that
the temporal side of the disc, even in the normal eye, is paler than
the nasal side. In the aged too the disc does not present the pink
transparent appearance seen in young people.

Symptoms. — In the first two forms of optic atrophy the acuteness
of vision is lowered, and as a rule the field of vision becomes con-
23

354 DISEASES OF THE EYE. [chap. xiii.

tracted, usually more at the nasal than at the temporal side. Sub-
sequently the temporal side of the field becomes contracted, and
finally a small eccentric portion of the field to the temporal side
may be all that remains, or even this may disappear, and absolute
amaurosis result. The colour-vision is always much affected. The
light-sense is affected, so that there is diminished sensibility for
differences of illumination ; while, in chorioido-retinal diseases,
there is defect in the quantitative perception of light, the minimum
quantity being larger than normal.

(c) Chorioido- Retinal Atrophy of the Optic Nerve {Waxy Disc)
is due to syphilitic retinitis, retinitis pigmentosa (Plate VI.), and
chorioido-retinitis. — The vessels here are much attenuated, and the
altered colour of the optic disc is a dull or dirty yellow, rather
than white or grey.

The two last varieties of atrophy are of course secondary to
disease within the eye. Simple atrophy may also be secondary, but
when it is so, it is due to pressure on the nerve fibres outside the eye
and may be brought about by a tumour anywhere in the course of
the nerve, by inflammatory exudations, by a splinter of bone in
cases of fracture of the skull, and, also, by pressure upon the chiasma
by the floor of the distended third ventricle in cases of internal
hydrocephalus.

Primary Optic Atrophy is often found associated with : —

Disease of the Spinal Cord {Spinal Amaurosis), especially loco-
motor ataxy. Optic atrophy occurs in 10 to 15 per cent, of the
cases of locomotor ataxy and is often an early symptom ; but,
again, it may not come on until the affection of the gait is well
pronounced, while in other cases it is not present at any stage.
It is a remarkable and important fact, first pointed out by Benedikt
of Vienna, that there is an antagonism between atrophy of the
optic disc and the other symptoms of tabes dorsalis ; that is
to say, it is rarely that a tabetic patient, in whom optic atrophy
comes on in an early stage of his disease, becomes ataxic ;
and frequently, in these cases, when the blindness has advanced,
the disease becomes stationary. But if amaurosis do not come
on until the ataxy is well developed, no improvement in the latter
is likely to be noted. Atrophy of the optic nerve also occurs in
cases of infantile tabes.

More rarely, atrophy is found with disseminated sclerosis, and

crrAP. XIII.

THE OPTIC NERVE.

355

lateral sclerosis of the spinal cord. In general paralysis of the insane,
although spinal disease is not always present, atrophy of the papilla
frequently occurs.

It is probable that the disease commences at, or close to, the
papilla in spinal cases.

Symptoms. — Central vision is affected at an early stage in the
disease, and eccentric contraction of the field (Fig. 115) usually
appears at the same time. The contraction may be concentric, or
it may be more marked in one direction than another. This

Left Field

Right Field

Fig. 115. — Case of Locomotor Ataxy. Atrophy of each optic nerve
R.E. Marked contraction of field — absolute defect for white. No colour
perception in remaining portion of field. Central V = fingers at 3*0 m.
Very white optic disc. Became quite blind five months later. L.E. Only
slight loss in periphery of field. Fields for colour irregularly contracted.

Outer boundary for red , for blue . Central V = 6/12. White optic

disc. Became quite blind a year later.

concentric contraction advances gradually towards the centre of
the field from every side, until it finally engulfs the fixation point.

Occasionally the affection begins as a central scotoma, accom-
panied by eccentric defects of the field. Sometimes also defects of a
hemianopic or sector-like type occur. Colour-blindness is an almost
constant symptom. As a rule absolute blindness is brought about
in the course of a year or two, or it may come on more rapidly.

It is doubtful whether Primary Optic Atrophy of the progressive
form just described can occur, as a purely local disease, without
any other defect in the system. These cases if followed up wo aid

356 DISEASES OF THE EYE. [chap. xiii.

probably be found to develop some form of disease of the nervous
system.

As the result of Poisoning with Organic Preparations of Arsenic. — These
preparations have come much into use far the treatment of sleeping
sickness and of many other diseases caused by protozoa, but unfortunately
they are liable to give rise to optic atrophy and complete blindness.
Many cases of blindness have been recorded from the use of atoxyl, and
arsacetin has also caused it. No case of blindness from the use of salvarsan
has been recorded. The accident cannot be avoided, for it depends not
so much on the size of the dose as upon individual predisposition. But
it seems to be less dangerous to give one large dose than small repeated
doses. It may be that the blindness caused by atoxyl has been due to
the methyl alcohol used in its preparation, rather than to the arsenic ;
and we understand that for this reason Professor Ehrlich now no longer
uses methyl alcohol for this purpose. When atrophy of the optic nerve
once sets in, discontinuance of the use of the preparation does not avail
to arrest the progress of the blindness. The features of this optic
atrophy are : — Onset with haziness and scintillation, and progressive
contraction of the field of vision, especially on the nasal side. Central
vision remains good until the field has become very small, and in the
course of a few months complete loss of sight ensues. The optic nerve
is pale and sharply defined. The vessels are much reduced in size.

Poisoning by the inorganic arsenic preparations does not cause optic
atrophy and amaurosis. The impairment of vision is only slight, there
is no contraction of the field, but a central colour-scotoma is present.
The ophthalmoscope may show some pallor of the temporal half of the
optic disc. Discontinuance of the drug is followed by recovery of sight,
and no case of total blindness has been recorded. The inorganic arsenic
preparations cause conjunctivitis and oedema of the ej^elids, while the
organic preparat^ions do not do so.

Treatment. — In neuritic atrophy, so long as there are signs of
active inflammation, antiphlogistic measures — Heurteloup's leech
to the temple, hot foot-baths, rest of body and mind, dark room,
iodide of potassium, and, especially, mercury internally, when other-
wise admissible — are to be adopted. At a later period, hypodermic
injections of strychnia {^-^ gr., increased gradually to ttV or ^^ gr.
once a day) and galvanism may be tried. Hypodermic injections
of antipyrin (about 7| grains every second day) have been given
with some benefit in these cases.

In spinal amaurosis, and in optic atrophy occurring as a local
disease, strychnia hypodermically and the galvanic current sometimes
improve vision for a time. Phosphorus internally may be given.

The treatment for optic atrophy, due to other causes, is to
be directed to the primary disease.

OHAt. XIII. 1 THE OPTIC NERVE. 357

The Prognosis is very serious ; for, although every therapeutic
measure may have been employed, amaurosis is the ultimate result
as a rule. Cases of primary atrophy due to poisoning by organic
arsenic preparations are hopeless from the beginning.

Hereditary Of tic Atrofhy (Leber's Disease), see p. 347.

Tumours of the Optic Nerve will be treated of in chap. xx.

Hyaline Outgrowths from the optic papilla, at its edge or centre, are
occasionally met with. Seen with the ophthalmoscope, they present the
appearances of small bluish-grey semi- translucent nodules. Those which
appear at the edge of the disc only are of the same nature as the " colloid
bodies " which occur in guttate chorioiditis (p. 191). In many instances
retinitis pigmentosa is also present. These outgrowths do not always
of themselves cause a defect of sight, and rarely cause serious blindness.

Treatment is of no avail.

Injuries of the Optic Nerve. — In addition to those injuries
which result from direct violence with sharp instruments, etc.,
entering the orbit, the optic nerve may be injured by falls on the
head. Fractures of the base of the skull frequently involve injury
to the optic nerve. But even where no fracture occurs, blindness
with atrophy of the optic nerve, usually only in one eye, may follow
a blow, or fall, on the head ; and in these cases concussion of the
nerve at its passage through the optic foramen, or fracture of
the optic foramen, or an extravasation of blood in the sheath of the
nerve, is probably the immediate cause of the atrophy.

Haemorrhages from the Stomach, Bowels, or Uterus are capable of giving
rise to serious and incurable blindness.

Blindness during or immediately after a severe haemorrhage is prob-
ably due to insufficient blood-supply to the nerve-centres and retina,
accompanying general exhaustion of the system. For such cases the
prognosis is favourable.

But there is another class of cases of very much more serious import.
Fortunately, they are rare. In these the defect of vision does not come
on until from two to fourteen days after the haemorrhage, when the general
system is recovering. Even comparatively slight haemorrhages, w^hich
caused no marked anaemia, are said to have been followed by blindness.
The pathogenesis of these cases is not yet clearly made out. Leber
inclines to the belief that the blindness here is due to an extravasation
of blood at the base of the skull, and into the sheath of the optic nerve ;
but, even then, the relationship between this and the stomachic or uterine
haemorrhage is not rendered clearer. Papillitis has been several times
noted with the ophthalmoscope ; and this circumstance makes it probable
that neuritis is the immediate cause of blindness — even in those cases

358 DISEASES OF THE EYE. [chap. xiii.

which show no ophthahiioscopic sign of it — and hydraemia may possibly
be the influence which calls forth the neuritis.

The Defect of Vision may be but slight, or it may amount to absolute
amaurosis. Both eyes are usually affected in equal degree. But cases
have been observed in which one eye was completely amaurotic, while
the vision of the other eye was quite normal ; and such cases prove that
the lesion is peripheral — in fact, that it lies on the distal side of the optic
commissure. The field of vision is frequently contracted, either concen-
trically or segmentally ; and, even when central vision recovers, the field
may remain contracted. The presence of central scotoma has also been
observed in some cases.

The Ophthalmoscopic Appearances which are present immediately on
the occurrence of the blindness have not as yet been observed. A few
weeks later they are different in different cases. They have been found
at this period normal ; or presenting slight paleness of the papilla and
contraction of the arteries ; or there was marked paleness of the papilla,
and the arteries were extremely contracted, with slight distension of
the veins ; or paleness of the papilla was present, but its margins were
indistinct, and the surrounding retina somewhat swollen, while the retinal
vessels were normal. Small haemorrhages have repeatedly been seen in
the neighbourhood of the papilla. At later periods well-marked optic
atrophy is frequently observed.

Prognosis. — If in the beginning the defect of vision be merely amblyopia,
and not complete blindness, liopes may be entertained of marked improve-
ment, or of complete recovery. But Mooren saw slight amblyopia pass
into permanent amaurosis.

Haemorrhages from the stomach are those which are followed by the
most complete and permanent blindness, while uterine haemorrhages are
more commonly followed by less serious degrees of blindness.

The Treatment must consist of internal remedies calculated to correct
the general anaemia, such as iron, beef-tea, and meat extracts, wine, etc.
Strychnine hypodermically, to stimulate the nerve, may be employed.

Glycosuric Amblyopia.— In addition to the retinal affections
dependent upon diabetes (p. 318), we recognise the occasional oc-
currence in that disease of defects of vision which are referred to
disorder of the optic nerve, and which are not always accompanied
by ophthalmoscopic changes. These defects of vision are found
in the form of (1) Central Toxic Amblyopia (p. 349), or, in slighter
cases, as amblyopia without central scotoma. Occasionally, higher
degrees of amblyopia with concentric contraction of the field of
vision, and yet negative ophthalmoscopic appearances, are present.
(2) Atrophy of the optic nerve. This may appear in the usual form
as progressive blindness, with concentric contraction of the field
of vision ; or it may come on after the slighter form of amblyopia
has existed for some time. (3) Hemianopsia and colour-blindness.

OHAP. XIII. i THE OPTIC NERVE. ^50

It is probable that these apparently different kinds of blindness
depend upon similar pathological processes, and merely indicate
degrees of the latter. In what these processes consist is still un-
known ; but the tendency to haemorrhages in the retina in diabetes
makes it likely, that haemorrhages in the optic nerve are sometimes
the source of the amblyopia in question ; while the cases with
central scotoma are no doubt due to axial neuritis, similarly as
in alcohol and tobacco amblyopia.

Amblyopia is sometimes the earliest symptom of diabetes ;
and, consequently, it is of the utmost importance to examine the
urine for sugar in every case of amblyopia where the ophthalmo-
scopic appearances are negative, or where the only abnormality is
atrophy of the optic papilla.

The Treatment indicated is solely that for the general disease, and
the prognosis for vision depends upon the amenability of the latter
to treatment, and upon the extent to which organic changes in
the optic nerve have advanced.

CHAPTER XIV.

Part I. — Ocular Diseases and Symptoms liable to accompany Focal

Disease of the Brain.
Part II. — Ocular Diseases and Symptoms liable to accompany

Diffuse Organic Diseases of the Brain.
Part III. — Ocular Diseases and Symptoms liable to accompany

Diseases and Injuries of the Spinal Cord.
Part IV. — Nervous Amblyopia, or Asthenopia.
Part V. — Various Forms of Amblyopia.

Part I.

OCULAR DISEASES AND SYMPTOMS LIABLE TO ACCOMPANY
FOCAL DISEASE OF THE BRAIN.

Hemianopsia [ri^ic-v^, half ; d, friv. ; wi//, the eye). — This symp-
tom consists in a loss of sight in one-half of the field of vision —
usually of each eye — consequent upon a lesion either at the cortical
centre for vision, or at the optic commissure (chiasma), or at some
point in the course of the visual path in the brain between these
two places. The term is not used for cases in which one-half of
the field is lost, owing to disease (detachment of the retina, etc.)
within the eye itself.

In hemianopsia the line dividing the seeing from the blind
half of the field passes vertically down the centre of the latter ;
or, it lies a little to one side of the centre of the field, so as to admit
of the centre being included in the seeing part ; or — although
in other respects the dividing line lies in the centre of the field —
the fixation point is circumvented by it, so as to leave that point
free, as in Fig. 116 ; and this latter is the most common arrange-
ment. All these varieties are termed complete hemianopsia.

Furthermore, cases occur which are properly regarded as hemi-
anopsia, and yet in which only the upper or the lower half of one side
of the field is wanting. This is termed incomplete or partial hemian-

360

OHAP. XIV.]

FOCAL BRAIN DISEASE.

361

opsia. If all three visual perceptions be lost, the hemianopsia
is called absolute (Fig. 116) ; but if only one (colour) (Figs. 117 and
118) or two (colour and form) be wanting in the defective part of
the field, it is termed relative hemianopsia. Relative hemianopsia
is the result of a lesion of less intensity than that which causes
absolute' hemianopsia. The vast majority of cases of hemianopsia
are absolute.

Homonymous Hemianopsia is the most frequent form. In it
the corresponding half — the right half or the left half — of the field
of each eye is wanting, as in Figs. 116 and 118.

Bi-Temporal Hemianopsia is much less common. Here the

Left Fiela

Fig. 116. — Case of Right Homonymous Hemianopsia, with word-blind-
ness. Line of demarcation passing round fixation point.

loss of vision exists in the outer side of each field, in consequence of
loss of function in the mesial half of each retina.

Superior or Inferior Hemianopsia, also called Altitudinal Hemi-
anopsia, in which the upper or lower half of the field is blind, is ex-
ceedingly rare-; and it is doubtful whether Nasal Hemianopsia has
really been observed, although it has been described. In the latter
form the inner side of the field of one eye only is lost.

Cases of Double Hemianopsia are those in which, owing to a
cerebral lesion on each side of the brain, both sides of each field
are lost. Usually in these cases the functions of the yellow spot
are spared with a corresponding small central field. Or, the whole

302 DISEASES OF THE EYE. [chap. xiv.

of one side of each field, and only half of the other side of each field
may be lost.

As hemianopsia can be caused by a lesion in the optic com-
missure, or in the cortical cerebral centre for vision, or by one any-
where in the long visual path between those two points, it will be
convenient here to sketch

The Course of the Visual Path from the Retina to the Visual Centre
in the Cortex of the Brain.

Having passed along the optic nerve, the visual fibres coming-
from the mesial half of each retina, when they reach the optic com-
missure, cross to the opposite optic tract, while those from the
temporal side of each retina are continued in the tract of the same
side. In other words, the visual fibres from the homonymous half
of each retina — e.g. from the temporal half of the right retina, and
from the mesial half of the left retina — pass wholly through the
corresponding optic tract — in this case the right tract — on their way
to the primary optic ganglia. Therefore a lesion, say, of the right
tract, would cause loss of function of the corresponding half — the
right half — of each retina, and the symptom would be blindness
of the opposite half — the left half — of each field of vision, termed
left homonymous hemianopsia.

The primary optic ganglia are : — the external geniculate body,
the pulvinar of the optic thalamus, and the anterior quadrigeminal
body. It is the external geniculate body which receives the major
portion of the fibres from the optic tract, and it is the only one of
the primary optic ganglia, which undoubtedly is connected with
the act of vision, for a lesion of it invariably gives rise to homony-
mous hemianopsia. The fibres, which enter the external geniculate
body, end there in fine branching terminals which are in relation
with ganglion cells, the axis cylinders of which form the further
centripetal path to the cortical centre for vision. But the main
portion of these axis-cylinders, or fibres, passes into the pulvinar of
the optic thalamus, which also receives direct fibres from the optic
tract. Notwithstanding this anatomical fact, lesions confined to
the pulvinar do not cause hemianopsia, and hemianopsia occurring
with lesions of the pulvinar is due to interference with the functions
of the external geniculate body, or other portion of the visual path
outside the pulvinar. The anterior quadrigeminal body receives
a small portion of the optic tract fibres, but these are not visual

CHAP, xiv.l FOCAL BRAIN DISEASE. 303

fibres, and lesion of this body is never attended by hemianopsia.
From the external geniculate body fibres pass, by way of the retro-
lenticular portion of the posterior limb of the internal capsule, to
the optic radiation, a large strand of fibres which run in the central
white matter of the hinder part of the cerebral hemisphere, and
terminate in the cortex of the occipital lobe. Lesions of the optic
radiation cause homonymous hemianopsia. Although fibres can
be anatomically traced, passing from the pulvinar to the optic
radiations through the retro-lenticular portion of the internal cap-
sule, yet lesions confined to the latter place do not cause hemianopsia,
and it is evident that the true visual fibres pass directly into the optic
radiation.

The optic radiation sweeps back through the parietal lobe, on
the outer side of the posterior horn of the lateral ventricle, to reach
the mesial surface of the occipital lobe, where the cortical centre
for vision is situated.

The visual path thus is : — optic nerve, optic commissure, optic
tract, external geniculate body, optic radiation.

In the path just described, visual neurons of four different orders are
concerned : The first neuron is represented by the rod or cone with its
nucleus in the external nuclear layer of the retina, the bipolar cells of the
inner nuclear layer form the second neuron, and they connect the first
with the third neuron, namely the ganglion cells of the retina and their
axis cylinders which pass upwards to the primary optic or basal ganglia,
and the cells of the latter with their axis cylinders, which pass up to the
visual centre in the occipital cortex, constitute the neuron of the fourth
order. Lesions in the basal ganglia or anywhere below, sooner or later
lead to descending degeneration and atrophy of the optic disc, whereas
lesions of the fourth or intracerebral neuron do not,

Henschen, as a result of his clinico-pathological researches, would
confine the cortical centre for vision to the middle part of the
calcarine fissure — the upper, or cuneic lip, representing the homo-
nymous dorsal retinal quadrants — while the lower or lingual lip
represents the homonymous ventral quadrants of the retina ; and
Bolton and Brodmann have shown that the histological structure
of this cortical region is highly specialised. FJechzig and others
give a wider area to the visual centre, which may extend they say
to the whole of the cuneus, and to the posterior part of the lingual
gyrus.

Lesions of the cortical centre for vision cause homonymous

364 DISEASES OF THE EYE. [chap. xiv.

hemianopsia. In cases of hemianopsia due to lesions of the optic
radiations or cortical centre, there is often a peripheral contrac-
tion in the seeing side of the field due to diminished functional
activity in the opposite side of the brain from that in which the
disease is situated.

That, in hemianopsia, the functions of the macula lutea are so
often spared (Fig. 116), indicates the existence of some special arrange-
ment of the visual path and cortical centre for this portion of the
retina. Henschen's investigations point to tlie maculo-cortical
centre as being situated in the anterior part of the floor of the
calcarine fissure, and to the whole of each macula as being repre-
sented in each maculo-cortical centre, causing an overlapping of
nervous supply in those regions ; so that in a lesion of one cortico-
macular centre the macular functions of each eye would continue to
be supplied by the cortico-macular centre of the healthy side of the
brain. Occasionally the double innervation is not present, and then,
in a cortical lesion, the dividing line in hemianopsia due to a corti-
cal lesion would pass through the fixation point. A sparing of the
macular functions is also usual in lesions of the most central por-
tions of the visual path. But in lesions of the peripheral portions
of the optic radiation, of the primary optical centres, of the optic
tracts, and of the optic commissure, the dividing line almost in-
variably passes through this fixation point. It is therefore prob-
able, that the point of decussation of the maculo-cortical fibres lies
somewhere in the middle third of the parietal lobe.

The Localisation of the Lesion in Cases of Hemianopsia is a subject
of interest, and, in cases of cerebral surgery, it may be of great
practical importance.

Lesions of the centre of the Optic Commissure, injuring the crossed
fibres, produce as their characteristic symptom bi-temporal hemi-
anopsia, which may be relative at first, beginning, for instance, as a
hemiachromatopsia (Fig. 117), but later on becoming absolute. In
some cases (basal meningitis, periostitis, hyperostosis) the diseased
process comes to a standstill, and the bi-temporal hemianopsia
remains. But the disease usually extends to the uncrossed fibres,
and ultimately causes complete blindness. Optic atrophy, often
commencing on the inner side of the papilla, is nearly always present
at some period of the disease. Other symptoms which may be
present in lesions of the chiasma are anosmia, paralysis of orbital

CHAP. XIV.] FOCAL BRAIN DISEASE. 365

nerves, and anaesthesia of the conjunctiva and cornea. The causes
are : fractures of the body of the sphenoid, cysts, tubercle, tumours,
•exostoses, distension of the floor of the third ventricle in cases of
internal hydrocephalus, and, most frequently of all, tumours of the
pituitary body. In the latter case proptosis, discharge of fluid
from the nostril, and diabetes may be present. Syphilitic gum-
mata may c-ause transient recurrent attacks of bi-temporal hemi-
anopsia.

In Altitudinal Hemianopsia the lesion must also, as a rule,
be at the chiasma, encroaching on it from above or below. Sym-
metrical cortical lesions might, and optic neuritis sometimes does,
produce it.

In Nasal Hemianopsia, too, the lesion must be at the chiasma,
and must be so situated in its outer angle as to involve only the
fasciculus lateralis or uncrossed fibres of the affected eye. The
occurrence of binocular nasal hemianopsia is evidently almost
impossible, implying, as it does, symmetrical lesion of the fas-
ciculus lateralis of each tract. According to Henschen, a tumour
in the external angle of the chiasma is apt to affect the crossed
fibres as well as the uncrossed, and to produce a form of bilateral
homonymous hemianopsia.

Bi-temporal hemianopsia is a common and early symptom in
enlargement of the pituitary body which may be associated with
Acromegaly, or Gigantism, or with Frohlich's Syndrome, namely,
general adiposis, retarded sexual development, etc. In some cases
headache and somnolence may be the only noticeable symptoms,
while in most acute cases ocular paralysis may also be present. In
most cases a radiograph will show enlargement or absorption of
the Sella turcica. The hemianopsia in the earliest stage may exist
for colours only as in one of our cases (Fig. 117). In some
instances, during the active stage of the disease, only a bitemporal
central scotoma exists, and in such cases the central vision is sooner
affected. Bitemporal hemianopsia in rare cases may be a symptom
of fracture of the base of the skull. It also may be due to basal
syphilis or sphenoidal disease.

Heteronymous (nasal or bitemporal) hemianopsia differs in several
ways from homonymous defects. In the former the defects in the
two eyes are often unsymmetrical, the line of separation may be
irregular, there may be contraction of the seeing halves of the

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306

CHAP. XIV.] FOCAL BRAIN DISEASE. 367

fields, the central vision is more affected, and optic atrophy or
even optic neuritis is much more common.

In Homonymous Hemianopsia — which is the commonest form
of the symptom — localisation of the lesion is a more difficult matter
than in any of the other forms ; for here the disease cannot be
situated at the optic commissure, but may be in the optic tract,
or in the visual centre, or anywhere in the lengthened course of
the visual path which connects these two parts.

Can we distinguish a complete and absolute hemianopsia, due
to a lesion confined to the cortical centre for vision, from a similar
defect in the field, due to a lesion in the optic radiation, external
geniculate body, or optic tract ? We may conclude that the hemi-
anopsia depends upon cortical lesion, if it be unaccompanied by
hemiplegia, motor aphasia, or paralysis of cerebral nerves, as direct
symptoms ; any or all of these are liable to accompany lesions of
the occipital lobe as distant ^ symptoms. Pressure of a cerebellar
tumour may interfere with the functions of the healthy cortical
centre for vision.

Aphasia, too, occasionally accompanies right cortical hemi-
anopsia [i.e. due to a lesion in the left occipital lobe), although it
is not easy to offer a satisfactory explanation of the fact.

Cortical hemianopsia may be a distant symptom. Cowers has
observed that, at the onset of many attacks of cerebral haemorrhage,
hemianopsia is present as a distant symptom of a transitory char-
acter — so transitory, indeed, that it does not complicate attempts
at localisation. Except under this condition, distant hemianopsia
seems to be rare — a fact which enhances the localising value of
the symptom.

Cortical hemianopsia may be incomplete, the homonymous
quadrant only of each field being wanting, if the lesion be con-

^ The term ' distant symptom ' is suggested in preference to those
in common use — namely, ' indirect symptom ' and ' pressure symptom.'
We cannot assume that these symptoms are less the direct result of the
lesion than any of the others which are present ; and, in many instances
at least, it is certain that they cannot be due to pressiire. In short, we
do not know what produces these symptoms — they may be caused by
inhibition — we only know that they are the result of interference with
functions of parts of the brain not involved in the lesion ; and the term
' distant symptom ' conveys this idea sufficiently well without committing
us to any theory. The corresponding German term is ' Fernwirkung.'

368

DISEASES OF THE EYE.

[chap. XIV,

fined to the upper or to the lower lips of the calcarine fissure
(p. 363).

In cortical lesions the hemianopsia is usually absolute. But the
lesion may be such as to destroy only the colour-sense (Fig. 118),
without affecting the form- or light-sense. Again, the form-sense
may be lost in the half field along with the colour-sense, while only
the light-sense is retained. Furthermore, cases of hemianopsia
are on record in which, in part of the defect, both the colour- and
form-senses were absent, but the light-sense present, while in the
remainder of the defect all three visual perceptions were lost.

Lefi Field

Fig. 118.— Case of Left Homonymous H etniachromatopsia (colour vision
only was lost in the dotted portion of left half of each field), with absolute
homonymous defects at A. Line of demarcation passing through fixa-
tion point. Associated with partial mind-blindness. Outer boundaries
for coloiu-s in the right half of each field contracted and reversed. Outer

boundary for red -.-.-., for blue , for green Slight

apoplectic attack. Lesion almost certainly in cortical centre.

It seems to be now proved that only a small portion of the Optic
Radiation can be regarded as consisting of visual fibres. A lesion
of the visual fibres of the optic radiation might be distinguished
from one in the cortical centre by hallucinations of vision occurring
in the former and not in the latter.

The symptoms, in addition to hemianopsia, due to disease of the
External Geniculate Body, which might serve to distinguish the hemi-
anopsia as being caused by a lesion there, have not as yet been
ascertained, the clinical evidence being indefinite. In these cases
the dividing Hue almost always passes through the fixation point.

CHAP, xiv.l FOCAL BRAIN DISEASE. 369

With hemianopsia from lesions of the Of tic Tract, the defect
in the fields may be relative (liemiachromatopsia) or incomplete
(only homonymous quadrants being lost), or complete and absolute,
and the dividing line almost always passes through the fixation
point. Lesions of the optic tract are, of course, apt to implicate
the cms cerebri, and in that case hemiplegia of the opposite side
of the body would be associated with the hemianopsia — e.g. lesion
of the right optic tract implicating the crus would be followed by
left homonymous hemianopsia and left hemiplegia. Symptoms may
also be caused by implication of cranial nerves, especially of those
which supply the orbital muscles (chap. xvi.).

Atrophy of the optic nerve, or neuritis, according to the nature
of the lesion, are frequently present.

A sign which is sometimes of localising value in lesions of the
optic tract, is the Hemianopic Pupil (Wernicke's pupil-symptom).
Illumination of the amaurotic halves of the retinae produces a
more sluggish pupil-reaction than when the light is thrown on the
seeing halves, because the lesion being on the distal side of the
corpora quadrigemina, the impulse cannot pass on to the centre for
the third nerve. The difhculty of concentrating light on the blind
side of the retina, without allowing the good side to be exposed
either to diffused or to diascleral light, is great ; and, unless it be
obviated, the experiment is vitiated. Moreover, the experiments
of Hess which would show that the pupillo-motor area of the retina
is confined to a region 4 mm. in diameter at the centre of the retina,
and that the pupil-reflex cannot be excited by illumination of the
periphery of the retina, introduces a further difficulty in the obser-
vation of this symptom, although it undoubtedly can be elicited,
and we have observed it extremely well marked in a case of bi-
temporal hemianopsia from tumour of the pituitary body.

The Diseased Processes which cause a Lesion of the Optic Tract
are : syphilitic gummata and syphilitic meningitis ; new growths,
including tubercle ; while softening and haemorrhage are rare.
Tumours of the optic thalamus, lenticular nucleus, or temporo-
sphenoidal lobe may also injure the tract by extension or pressure.

In hemianopsia the Prognosis for recovery of vision in the
defective halves of the fields depends, of course, upon the nature
of the lesion. But recovery is rare, especially in the most common
class of cases — those, namely, which are due to cerebral apoplexy.

370 DISEASES OF THE EYE. [chap. xiv.

In Right Homonymous Hemianopsia, wherever the position of the
lesion may be, a greater difficulty in reading is experienced than in left
hemianopsia. This is due to the fact that we read from left to right ;
and that, owing to the defect being on the right side, the word immediately
following that at which the patient is looking cannot be seen at the same
moment. A lesser difficulty in reading occurs in cases of left homonymous
hemianopsia — namely, when the commencement of the line following
that which is being read has to be picked up.

Word-Blindness is the term given to an inability to understand written
or printed characters, although they and other small objects can be dis-
tinctly seen. Other visual objects are named with ease (no visual aphasia).
The patient can express his ideas in writing, or write from dictation,
yet cannot understand what he has just written, nor can he copy written
or printed words. He understands the meaning of spoken words, and
the use of all objects around him (no mind-blindness). He can generally
recognise individual letters with some difficulty. This is ' pure word-
blindness,' or ' sub-cortical alexia.' When combined with inability to
write spontaneously or from dictation, it is known as ' cortical alexia.'
The condition has been occasionally complicated with right homonymous
hemianopsia (Fig. 116). In those cases where an autopsy was obtained
the lesion was found in the left occipital lobe. Word-blindness with
agraphia or cortical alexia is due, according to Dejerine and AVernicke, to
a lesion in the ce itre for visual memory for words, which, in right-handed
people, is the left angular gyrus and inferior parietal lobule.

Congenital Word-Blindness is probably not a rare condition, although
liable to be overlooked. It is shown to be present when it is found ex-
ceedingly difficult, or, in severe cases, impossible, to teach a child with
healthy eyes, normal acuity of vision, and good general intelligence to
read, sometimes even common words of one syllable, although he can learn
to recognise them if permitted to spell them aloud. The defect is probably
due to imperfect development of the cortical centre for the visual memory
for words in the left cerebral hemisphere, while the centre for the auditory
memory of words is unimpaired. As a rule, except in the severest cases,
numerals and music can be read. Hemianopsia is never associated with
this state. The condition sometimes runs in families. When the word-
blindness is not very marked, and when it is recognised in childhood, a
great deal can be done by careful, long-continued, and individual tuition
to effect a cure. These children should not be sent to school. Cures
are probably brought about by stimulation of the defective word-memory
centre, or by development of the corresponding centre in the opposite
side of the brain.

Visual Aphasia consists in inability to name objects seen, the use of
which is kno-s^m. The objects can be named, if the patient be allowed
to feel them even with his eyes closed. A few cases of this affection have
been recorded, and in all there was right homonymous hemianopsia.
Alexia and agraphia sometimes coexisted.

Dyslexia. — This symptom was first described by Berlin. In a wide sense
it belongs to the aphasic group, and is in fact a limited form of visual
aphasia. It consists in want of power on the patient's part to read more

CHAP. XIV.] FOCAL BRAIN DISEASE. 371

than a very few — four or five — words consecutively, either aloud or to
himself. The difficulty is not caused by dimness of sight, nor by pain in
the eye or head, but simply by an unconquerable feeling of dislike or
disgust, due to the mental effort. After a few words which can be well
understood have been read, the book is pushed away, and the head drawn
backwards and tm-ned aside ; and then in a moment or two the patient
may be tempted to repeat the effort, but with the same result after a
very few words have been read. The symptom comes on suddenly, and
has been usually the first sign of the presence of cerebral disease. Although
in most of the cases the dyslexia disappeared in the course of a few weeks,
either permanently or to recur later on, yet other symptoms soon followed
its first onset, such as headache, giddiness, aphasia, hemianopsia, paralysis
of the tongue, hemiansesthesia, hemiplegia, twitching of the facial muscles,
etc. All the recorded cases had a fatal termination. The lesion was
situated, in all but one of those cases where an autopsy was obtained, in
the neighbourhood of Broca's lobe. In one case the left hemisphere was
normal, while the right hemisphere was extensively diseased.

Amnesic Colour-Blindness is a symptom which is most probably due
to a lesion in the occipital lobe, interrupting the paths between the centre
for vision and the speech centre. It has always been accompanied
by right homonymous hemianopsia. In this condition the patient sees
colours and can recognise them, and he can perform the colour tests, but
he is unable to name each colour.

Visual Hallucinations may occur in cases of homonymous hemianopsia
in the blind side of the field only, and are due to irritation of the visual-
memory centre. Homonymous hemianopic hallucinations, persisting for
years without hemianopsia, have also been observed. Visual hallucina-
tions also occur very occasionally in connection with glaucoma.

Mind-Blindness, also called Optic Amnesia, is a symptom fu^st observed
by Munk in his experiments upon dogs. It consists in the loss of power
of recognising objects, while the power of seeing them remains. A whip
is seen by the animal, but inspires no terror ; a tempting morsel is seen,
but excites no desire. The symptom was caused by destruction of a region
situated chiefly in the posterior division of the second external convolution
of the dog's brain.

It has also been observed in man. The patient fails to recognise the
most familiar objects by sight. In one case the patient could not recognise
his wife until he heard her voice. There are two forms of mind-blindness
— the cortical and the transcortical. In the former, the lesion is in the
centre for memory ; and the patient has lost the power of visual imagina-
tion, and cannot describe visual objects from memory. In the latter, the
connecting path between the centre for vision and the visual memory centre
is interrupted, and the patient, though he can describe an object from
memory, is unable to recognise it when looking at it. Loss of the faculty
of orientation is a form of mind-blindness. Hemianopsia is present in
the majority of cases of mind-bliadness ; and colour-blindness, complete
or hemianopic, is not unusual. The lesion has been found in the occipital
lobe, usually on the left side, involving sometimes the parietal convolu-
tions. It usually consists in haemorrhage or softening, and the symptom

372 DISEASES OF THE EYE. [chap. xiv.

is consequently s\idden in its onset ; but it also occurs from tumours.
Exhausting illnesses, by reducing the mental energy, may produce a con-
dition of mind-blindness.

Some authors localise the centre for visual memory in the angular
gyrus, whilst others take for it the whole of the occipital lobe, except
the cuneus and its neighbourhood.

Part II.

OCULAR DISEASES AND SYMPTOMS LIABLE TO ACCOMPANY
CERTAIN DIFFUSE ORGANIC DISEASES OF THE BRAIN.

There are organic diseases of the brain which are not focal, and
which, as they attack extensive regions of the brain substance, may
be called diffuse. Under the same heading may be placed some
diseased cerebral states which we cannot doubt are organic, although
their pathology is as yet unascertained. It is proposed here to
describe the points of ophthalmological interest which belong to
some of these diffuse brain diseases.

Disseminated Sclerosis of the Brain and Spinal Cord.— Central
Colour Scotoma is the most usual defect of sight in this disease (Fig.
119), and in a few cases absolute central scotoma is present. It
is due to retro-bulbar neuritis (p. 347), which is now recognised
to occur most commonly as a symptom of disseminated sclerosis.
Irregular defects in the periphery of the fields — sometimes only for
colour — or regular concentric contraction may be found. These
defects may be in one or in both eyes ; they most commonly come
on very rapidly, and they often get better, or may, after a time,
get quite well. Even complete blindness, lasting as long as several
months, occasionally occurs ; but permanent complete blindness
is rare. The opthalmoscopic appearances do not always coincide
with the state of the vision ; for with marked defect of sight the
fundus oculi may be normal, or the vision may be normal, while
the optic papilla looks diseased, or both sight and ophthalmoscopic
appearances may be abnormal. The most common opthalmoscopic
change is a not very intense atrophic appearance of the whole surface
of the papilla, or its temporal third alone may be affected in this
way. But in these latter cases, where the temporal third alone
shows atrophy, a central scotoma is not necessarily present, nor
9,re the papillo-macular fasciculi in the nerve diseased. In a very

CflAP. XIV. i

DIFFUSE BRAIN DISEASE.

3?S

few cases optic neuritis becomes apparent at the papilla. The
ophthalmoscopic changes may be present in both eyes or in only
one. Uhthoff has shown by pathological investigations that, in
disseminated sclerosis, disease can exist in the trunk of the optic
nerve, without any abnormal ophthalmoscopic appearances, or defect
of sight. Sometimes defects of vision and ophthalmoscopic changes
precede all other symptoms by long periods, or they appear in the
very early stages of the disease ; but more commonly they do not
come on until other symptoms have been present for some time.
In all cases of retro-bulbar neuritis exaggerated tendon reflexes and

Lex't field

Right Field

Fig. 119. — Case of Disseminated Sclerosis. In right field a very small
central scotoma for pale green, and relative for white. A mist before the
R.E. for fourteen days, otherwise strong and healthy. Fundus normal.
V = 6/18. Exaggerated knee-reflex. No nystagmus, nor nystagmic
twi tellings. A week later nystagmic twitchings in extreme lateral posi-
tions. L.E, healthy.

other well-known signs of disseminated sclerosis should be looked
for. At the commencement of the attack of defective vision, the
patient complains of some pain on movement of the eyeball, and
gentle pressure backwards of the globe causes pain in the back of
the orbit.

Nystagmus, isolated and often fleeting paralyses of orbital
muscles, especially of the sixth nerves, and nuclear paralysis, are de-
rangements of the oculo-motor apparatus, which are liable to be
present in disseminated sclerosis. Marked exterior ophthalmoplegia
is rare ; but the paralyses of nuclear origin of which there can be no

374 DISEASES OF THE EYE. [chap. xiv.

doubt, are loss of conjugate motion to one or other side, and defective
power of convergence. Nystagmus is present in about 50 per cent.
of the cases, and is either of the ordinary kind or consists merely
in nystagmic twitchings, more particularly at the extreme lateral
position of the eyeballs. Very slight twitchings in these extreme
positions are of no import, as they occur even in the healthy state.
As true nystagmus is an uncommon symptom in other diseases of
the general nervous system, it is of considerable value in the diag-
nosis. Nystagmic twitchings, while they do occur in other general
nervous diseases, are more common in disseminated sclerosis than
in any other of these diseases. Miosis may be present.

Disseminated sclerosis in its early stages is apt to be mistaken
for hysteria, owing to the presence of such symptoms as transitory
loss of power in limbs, aphonia, convulsive seizures, hysterical
manner, and so on, and here the eye-symptoms may come to our
aid. In hysteria the ophthalmoscopic appearances are normal ; the
fields of vision, if deranged, are contracted, central scotoma being
rare, and when the fields are contracted the colour boundaries often
do not recede in their regular order — the field for red, for example,
may be wider than that for the other colours. In hysteria, again,
it may be found impossible to examine the colour fields at all, all
colours being named dark or black ; and finally oculo-motor dis-
turbances rarely occur.

Diffuse Sclerosis of the Brain. — In. some rare cases of this disease,
headache, \omiting, and double optic neuritis may lead to the diagnosis
of cerebral tumour, an error in diagnosis which, with our present know-
ledge, it is impossible to avoid, unless there be also focal symptoms that
would point with certainty to a tumour. The mistake will not often
occur, as diffuse sclerosis of the brain is exceedingly rare.

General Paralysis of the Insane. — Derangements of the intrinsic
muscles of the eyeball, orbital paralyses, atrophy of the optic disc,
and mind-blindness are the eye-symptoms which may be found in
this disease.

The Pupil, etc. — The pupils are usually contracted in the early
stages, and dilated at later periods. An early symptom is slight
inequality in the pupils (Anisocoria), with somewhat sluggish reaction
of the wider one, and, also at an early period, there is apt to be loss
of the pupil-reflex to sensory stimuli. Later on the larger pupil
does not react to light at all, while its fellow does so normally, and

CHAP. XIV.] DIFFUSE BRAIN DISEASE. 375

sight is good. Sometimes the inequality of the pupils varies, so
that the pupil which was at first the larger, now becomes the smaller
one. The so-called paradoxical pupil-symptom is an early augury
of coming paralysis, and consists in this, that when a strong beam of
light is thrown into the eye with the focal illumination, the pupil
at first contracts fairly well, then dilates slightly, contracts again,
and after a few such oscillations finally dilates widely, although the
strong light still shines into the eye. The Argyll Eobertson pupil
is only found in some cases, and then usually in the late stages, but
it does occasionally present itself in the initial stages. Sometimes
the pupil is irregular in shape.

Paralyses of Orbital Muscles. — These are of rarer occurrence than
paralysis of the pupil ; but the third and sixth nerves are occasionally
paralysed even in the early stages, and in these stages, too, ptosis
and transient nystagmus and twitchings of the eyelids may be
seen.

Oftic Atrophy. — This is found in 8 to 10 per cent, of the cases of
general paralysis, and is then seen for the most part in the late stages.
But it has sometimes come on in a very early period, and has even
preceded every other symptom by several years. It generally ends
in blindness. Occasionally slight hyperaemia of the disc or optic
neuritis is seen. Atrophy of the optic nerve and orbital paralyses
are more often seen when tabetic symptoms are present.

Mind-blindness occurs in cases of general paralysis, usually in
the advanced stages.

Amaurotic Family Idiocy. — This disease occurs in children during
the first year of life, and most, if not all, of the cases recorded occurred in
Jewish families. Family predisposition is strongly marked, as many
as five children in a family of seven having been attacked. The causes
which have been assigned are neurotic taint, blood relationship between
the parents, and traumatism of the mother during pregnancy. Syphilis
does not seem to play any part in the etiology.

The children are born sound and healthy, and continue to be so for
some months. They then cease to develop mentally, and idiocy is gradu-
ally established. At the same time paresis or paralysis, either flaccid or
spastic, of the greater part of the body appears, while the reflexes may be
deficient or increased. Hyperacusis is often present. A chief and very
early symptom of the disease is loss of sight, ending in absolute blindness,
with certain characteristic ophthalmoscopic appearances, and nystagmus
and strabismus are sometimes present. A slowly increasing marasmus
leads to a fatal termination before the end of the second year, as a rule.
Waren Tay first observed the peculiar ophthalmoscopic appearances, and

376 DISEASES OF THE EYE. [chap. xiv.

Sachs described the clinical history, general symptoms, and morbid changes
in the brain.

The ophthalmoscopic appearances are as follows : — There is at first
no change in the optic discs. At the macula lutea in each eye there is a
large white spot, rather diffuse, with softened edges, and about twice the
size of the optic papilla. In its centre there is a brownish-red, fairly
circular spot, which contrasts strongly with the white around it. This
central spot, as Tay says, has not the appearance of a hsemorrhage, nor of
pigment, but suggests a gap in the white patch through which the healthy
structures are seen. In short, the appearance reminds one of that seen in
cases of embolism of the central artery of the retina (p. 325 and Plate VII.
Fig. 1). At a later period, with complete amaurosis, atrophy of the optic
nerve is found.

In the brain the pathological changes consist in degeneration of the
pyramidal cells of the cerebral cortex. In the pons and medulla oblongata,
degeneration of the pyramidal fibres and of the fillet has been found ; and
in the spinal cord, degeneration of both the crossed and direct pyramidal
tracts has been seen and also disease of the ganglion cells of the retina
similar to that in the cerebral cortex. The normal absence of the ganglion
cell layer at the macula lutea, and the fact that it is thickest just
around the latter, go far to explain the ophthalmoscopic appearances.

Maculo-Cerebral Degeneration (Familial). — In this disease, as in that
just described, disease of the macula, which affects several members of a
family, is usually associated with defective intelligence, but it differs from
the former in as much as it begins at a later age and is not confined to
Jews. When about six or eight years of age, two or more of the children
are noticed to have defective sight and weakening of the intellect. As
the disease progresses they become imbecile but not completely blind.

The ophthalmoscope shows pallor of the optic discs with narrow vessels
and a peculiar affection of the retina at the macula lutea. The macular
changes consist of dirty, yellowish-grey spots and fine granular pigmenta-
tion, or sometimes there is a dark reddish pigmented patch ; minute whitish
dots may also be scattered over a larger area.

The defect in the vision reveals itself as a central scotoma, at first
relative and then absolute, with a normal peripheral field.

In cases which begin later, about twelve years of age, the intellect is
not affected as a rule. The cause and the pathology of the disease are
unknown. Consanguinity in the parents was noted in many instances.

Meningitis. — Inflammation of the cerebral meninges, of whatever
form, and whether at the base or on the convexity of the brain,
is liable to be accompanied by optic neuritis. In the early stages
irritative lesions may cause spasmodic miosis, and conjugate devia-
tions of the head and eyes, also of spasmodic nature. Later on
ocular paralyses, pain, or ansesthesia of regions supplied by the fifth
nerve, and defects in the fields of vision from pressure on the optic
tracts or commissure, may be found.

CiiAi>. XIV.] DIFFUSE BkAIN DISEASE. 37?

Acute Tubercular Meningitis. — In a large percentage of tlie cases
of this form of meningitis miliary tubercles in the chorioid are
present, if carefully looked for, and here the electric ophthalmoscope
is very useful (p. 220). Optic neuritis is more common than in any
other form of meningitis, as are also orbital paralyses, in consequence
of the tendency of this form to attack the base of the brain. The
paralyses are often transitory and variable.

Cerebrospinal Meningitis. — Eye-symptoms are often present
both in the epidemic and sporadic forms of this disease. Swelling
of the eyelids, conjunctivitis, and photophobia are frequent, even
in the early stages. The pupils may be unequal, contracted, or
dilated. There may be ulceration of the cornea, parenchymatous
keratitis, or deep purulent infiltrations. Eetinitis and plastic irido-
chorioiditis, followed by retinal detachment, may be found, or there
may be purulent irido-chorioiditis, with purulent infiltration of the
vitreous humour, going on to panophthalmitis. If the fundus can be
examined, optic neuritis or neuro-retinitis will often be seen, or throm-
bosis of the central vein, with retinal haemorrhages. Each epidemic
of cerebro-spinal meningitis is apt to be associated with some one of
these conditions as its special type of eye-affection. The eye-affections
in cerebro-spinal meningitis then are very grave ; but some of the
cases of irido-chorioiditis do recover, with retention of good sight.

Traumatic Meningitis. — Falls and blows on the head which do
not fracture the skull are held by many to be capable of causing
meningitis, and occasionally, che inflammatory process, reaching
the optic nerve, creeps down it to the optic papilla, where it may be
diagnosed with the ophthalmoscope.

Hydrocephalus. — Well-marked papillitis, or neuritic atrophy, is
sometimes found in congenital hydrocephalus, or in the hydro-
cephalus which makes its appearance in infancy or childhood ; and
it would probably be more common, but for the compensation for
the increased intra-cranial pressure, which distension of the sutures
and fontarelles must provide. In the acquired hydrocephalus of
later life, optic neuritis passing over to optic atrophy is the rule ;
and such cases may closely simulate an intra-cranial tumour in all
their other symptoms as w^ell. Bi-temporal hemianopsia is apt to
be present, owing to pressure on the optic commissure by the dis-
tended floor of the third ventricle. Vision has been restored by a
palliative decompression operation.

378 DISEASES OF THE EYE. [chap. xiv.

Infantile Paralysis. — Hemianopsia has been noted in a very
few cases of this affection ; and papilKtis, with some orbital paralysis,
has also been seen, but usually there are no eye-symptoms.

Paralysis Agitans. — In some cases a fine vibratory tremor may
be noticed along the margin of the upper lid, especially when the
eyes are closed, and the lids will be found to be unusually rigid on
an attempt being made at passive opening of them. The slowness
of muscular action in other parts does not affect the motions of the
eyeballs. If a patient be called on to look in any direction, the
eyes are instantly turned, while the head slowly follows them.

Epilepsy. — A visual aura is more common than any other special
sense aura in idiopathic epilepsy. It may take the form of sub-
jective sensations of lights, colour, flames, megalopsia or micropsia,
etc. ; or visual hallucinations may occur ; or there may be simple
homonymous hemianopsia. Where epilepsy is due to organic brain
disease, a visual aura, occurring ahvays in homonymous sides of the
fields, is important, as indicating the occipital lobe as the region of
the brain in which the discharge originates. At the onset of an
epileptic fit, there is often conjugate lateral deviation of the eyes
to the opposite side of the body from that on which the convulsions
commence, with rotation of the head in the same direction, while
subsequently the eyes may suddenly be turned in the opposite direc-
tion. The condition of the pupils varies, often even in one and the
same fit. At the onset they are usually normal or contracted ;
but during the tonic spasm they become dilated, and remain so
until consciousness returns. The pupillary light-reflex is lost — a
point of importance in the diagnosis of a true epileptic fit from an
hysterical attack, in which latter it is retained. After a fit, rapid
changes in the size of the pupil may sometimes be seen, and these
are valuable as evidence of the fit having been a genuine one. The
ophthalmoscopic appearances during a fit vary in different cases.
In some they are normal, in others there is marked pallor of the disc
and contraction of the blood-vessels, and, again, in others the papilla
is hypercemic and the retinal veins enlarged. Optic neuritis and
optic atrophy do not belong to epilepsy ; and if found they can
be regarded only "as complications. Between attacks the fundus
may be normal ; but it is not unusual to find a high degree of
hypersemia of the retina and papilla, which may continue for some
days or hours, or may even become chronic. The fields of vision

CHAP. XIV.] DIFFUSE BRAIN DISEASE. 379

after a fit, and sometimes as a permanent state, are concentrically
contracted ; or there may be colour-blindness, and the central
acuteness of vision may be reduced. The state of the fields is a
valuable aid in the detection of simulation. Transitory amblyopia
(migraine, scotoma, etc.) is more frequent in connection with epilepsy
than under any other condition. It may precede the true attack
by years, or it may occur with, or for an hour or so before, the fits,
or it may be substituted for them. Inasmuch as this transitory
amblyopia is often attended by disturbances in speech, or in the
intelligence, or by passing paralysis, and as both eyes are usually
attacked by it, frequently in the form of homonymous hemianopsia,
it is obvious that its cause resides in the visual cortex. Occasionally
the blindness is monocular, and must then be referred to disturbance
in the circulation of the retina or optic nerve. Given a predisposition
to epilepsy, irregularities in refraction may at times prove the ex-
citing cause of an attack ; and if correcting glasses be worn by these
patients at a sufficiently early period, the fits may cease, or at least
become less severe in a certain proportion of the cases. Further
investigations on this subject are required, especially as concerns
the permanence of cures.

Chorea. — It is probable, that in some cases, at least, of this
affection, cerebral embolism may be taken as the cause. Several
instances of embolism of retinal vessels have been seen in immediate
connection w4th the onset of chorea.

In chorea the eyes participate in the irregular jerky motions,
and the spasm may be so unequal in the two eyes as to cause brief
diplopia ; although, not being constant, it is little heeded by the
patients, and is rarely mentioned by them.

Part III.

OCULAR DISEASES AND SYMPTOMS LIABLE TO ACCOMPANY
CERTAIN DISEASES AND INJURIES OF THE SPINAL
CORD.

Tabes Dorsalis. — Amongst the ocular complications to be found
in this disease, Atrophy of the Optic Nerve (p. 354) is the most serious.
It occurs in about 20 per cent, of the cases, and commences more
frequently in the pre-ataxic period than subsequently. Rarely it is

380 DIjSEAJ^ES of the eye, [cHAi>. xiV.

the first symptom, preceding all spinal symptoms by from two
to twenty years, but it sometimes commences in the later stages
of locomotor ataxy. Coming on in the pre-ataxic stage, optic
atrophy seems very often to have, as it were, a favourable influence
on the spinal disease, the spinal symptoms already existing becoming
ameliorated or disappearing, while the further progress of the disease
is retarded or averted. It is indeed rare for tabetic patients who
go blind at an early stage of the disease to become ataxic later ;
but if the ataxy be once well marked, it does not improve with a
subsequent development of optic atrophy. It sometimes occurs
that the onset of optic atrophy in one eye precedes that in the other
by a long interval, even by many years ; but usually the eyes are
affected simultaneously, or at a short interval. The relation be-
tween the optic atrophy and the spinal disease is not as yet well
understood. The atrophy is probably merely a manifestation of
a diseased process in the optic nerve, similar to that which attacks
the posterior columns of the cord. The fields of vision are usually
concentrically contracted (see also p. 22).

Paralysis and Ataxy of the Orbital Muscles. — Paralyses of orbital
muscles in locomotor ataxy occur in about 30 to 40 per cent, of the
cases. They usually appear in the pre-ataxic stage, and even as an
initial symptom, and are of two kinds — namely, the transient
paralysis, which lasts a few days or weeks, and may recur ; and
the permanent paralysis of one or two muscles. Diplopia is pro-
duced by these paralyses, and is often the symptom which first
induces the patient to see his doctor. The sixth nerve is the one
most commonly paralysed ; but the third nerve is also often para-
lysed, including the branch to the levator palpebrse, with result-
ing ptosis. Loss of power of convergence is often present in com-
mencing tabes, and double exterior ophthalmoplegia, as well as double
sixth-nerve paralysis, is sometimes seen ; and there can be no
doubt but that all these three conditions, and probably also some of
the other oculo-motor disturbances in tabes, are often of nuclear
origin. But the orbital nerves may, it is found, undergo atrophy
without their nuclei being altered, and probably, therefore, some of
the ocular paralyses* here are due to peripheral neuritis.

Ocular ataxy is another not infrequent symptom in tabes. It
is sometimes erroneously called nystagmus ; but nystagmus is a
constant oscillatory motion of the eyeballs, both while the eyes are

CHAP. XIV.] SPINAL DISEASE. 381

at rest, and when they are looking at an object, and is extremely
rare in tabes. In ocular ataxy, so long as the eyes are at rest, there
is no oscillation or twitching ; but as soon as an object is carefully
looked at, and especially if followed when in motion, and more
particularly at the end of the latter, a slight twitching of the
eyeballs is seen. It may be found in any stage of tabes.

Pupillary Alterations. — Miosis is the usual state of the pupil
in tabes, and is held to be due to paralysis of the pupil-dilating fibres
from disease in the front part of the aqueduct of Sylvius. The
miosis is often extreme, or ' pin-hole,' as it is then termed ; yet
the pupil may react to light and on convergence. The pupil may
be of normal size in tabes ; but mydriasis, except as part of a third-
nerve paralysis, is rare. Again, both in the early and later stages,
the pupils may be of different sizes.

The Argyll Robertson pupil is an important symptom of tabes.
It consists in this, that, even with normal or fairly good vision, the
pupil, although as a rule contracted, does not respond to the stimulus
of light by further contraction, or but slightly, yet does become
more contracted on convergence of the visual axes (or on accommo-
dation). Miosis need not necessarily be present with the Argyll
Robertson pupil ; the pupil may be of normal size or dilated. The
symptom is one of those most regularly found in tabes. It is often
an early or initial symptom, and it continues through all the stages
of the disease. It is occasionally present in one eye only, and is
sometimes quite wanting. The pupillary reaction on convergence
alone in advanced optic atrophy must not be mistaken for an Argyll
Robertson pupil.

Neither the Argyll Robertson pupil nor primary optic atrophy
occurs in peripheral neuritis, a disease which is liable to be some-
times mistaken for tabes.

Paralysis of Accommodation without paralysis of the sphincter
iridis is a rare symptom in tabes. It is more common in the late
than in the early stages.

Narrowing of the Palpebral Fissure, due to a slight drooping of
the eyelids, hardly to be called ptosis, sometimes occurs in tabes
along with the miosis. It is held to be due to paralysis of the
sympathetic (sympathetic ptosis), is usually binocular, and the
frequency of its occurrence increases as the disease advances.

Twitchings in the Orbicularis Muscle for some Moments after

382 DISEASES OF THE EYE. [chap. xiv.

Closure of the Eyelids may sometimes be observed in tabes. Similar
twitchings may occasionally be seen in some other nervous diseases,
and even in bealtb, but less well marked. Probably their marked
character in tabes is due to very slight facial paralysis, and the
consequent imperfect power of closing the eyelids.

Hereditary Ataxy (Friedrich's Disease) presents few eye-symp-
toms, a fact of some diagnostic importance. Ocular ataxy (p. 380)
is the only one which occurs with any constancy. Optic atrophy is
of such rare occurrence in the disease, that it can hardly be reckoned
as one of its symptoms. Paralyses of orbital muscles and pupil-
symptom are also rare.

Myelitis. — Apart from the inflammation of its meninges (cerebro-
spinal meningitis), of which mention has already been made (p. 377),
acute inflammation of the cord may be associated with optic neuritis.
The optic nerve usually becomes inflamed before the spinal cord
but the myelitis may precede the optic neuritis, or they may occur
simultaneously. The relation of the optic neuritis and myelitis to each
other is, doubtless, nothing more than that each is a manifestation
of the presence in the system of one and the same toxic influence.
Rheumatism, epidemic influenza, and syphilis are amongst the causes
assigned in some cases, while in others no cause could be assigned.
The field of vision may be contracted, more rarely a central scotoma
is present, and the eyeballs may be painful on movement or on
pressure. If the cervical portion of the cord is inflamed, pupillary
symptoms — irritation mydriasis or paralytic miosis — are apt to be
present.

Syringomyelia. — Concentric contraction of the field of vision
without ophthalmoscopic changes, is the most constant eye-symptom
in this disease. It is not quite certain whether this abnormality of
the field is due, at least sometimes, to attendant hysteria, or is
always a symptom of the organic disease as such. Atrophy of the
optic nerve is exceptional and so are paralyses of the orbital muscles.
Inequality of the pupils has sometimes been noted and also
nysta,2;mus.

Myotonia Congenita (Thomsen's Disease).— In some cases of this
rare disease the external musculature of the eyes affords symptoms,
although the intrinsic muscles are never disordered. The opening
and closing of the eyelids may be difficult — they cannot be closed or
opened by one effort, successive jerky motions being required to

CHAP. XIV.] SPINAL DISEASE. 383

effect closure or opening. As in Graves' disease, when the eyes are
open the upper lid is apt to be retracted, and the upper lid does not
readily follow the downward motions of the eyeball. Transitory
amblyopia, or even amaurosis, has been noted in some cases.

Acute Ascending Paralysis (Landry's Disease). — Eye-symptoms
are rare in this disease, but there may be paralysis of some of the
orbital muscles, paralysis of accommodation, mydriasis, or loss of
the light-reflex.

Injuries of the Spinal Cord. — The condition which used to be
known as railway spine, but which is now better styled traumatic
neurosis, and is due to mental shock rather than to organic lesions
of the brain and spinal cord, is accompanied frequently by certain
functional eye-symptoms, of which the chief one is a contraction of
the field of vision similar to that found in some cases of hysteria.
In those much rarer cases of organic injury to the cord, or of myelitis,
or of haemorrhage in, or inflammation of, its membranes, following
on railway and other accidents, organic eye-disease seldom results,
although optic neuritis and optic atrophy were at one time held to
be frequent consequences of these injuries. If the lesion be in the
lower cervical region of the cord, the pupils are apt to be contracted
from sympathetic paralysis.

Part IV.
NERVOUS AMBLYOPIA, OR NERVOUS ASTHENOPIA.

The terms amblyopia and amaurosis are used to denote respectively,
a defect in the vision, or blindness, for which no assignable cause
can be detected in the eye itself. These terms are in fact relics of
the pre-ophthalmoscopic period, and are now much more restricted
in their use than in former days.

Nervous Amblyopia, or Nervous Asthenopia, occurs for the
most part in connection with three functional disorders of the nervous
system — namely. Neurasthenia, Hysteria, and Traumatic Neurosis.
Many observers, it is true, hold that these three conditions ought to
be regarded and treated of as hysteria, that the term neurasthenia is
quite superfluous, while traumatic neurosis is merely hysteria caused
by shock. This is not the place to enter into a discussion on this
question ; and it need only be said that while these various states of

384 DISEASES OF THE EYE. [chap. xiv.

the nervous system are admitted on all hands to have much in
common, and also to merge insensibly into each other, yet typical
cases of each are sufficiently differentiated to make it justifiable and
convenient to retain all three in our minds, as separate clinical
entities.

Neurasthenia may be described as abnormal susceptibility of the
nervous system to fatigue from mental or bodily exertion ; while in
hysteria the symptoms depend upon idea, the essence of hysterical
conditions being that ideas too easily excite abnormal changes in
the organism.

The defects of vision which accompany these disorders are, like
all their other symptoms, purely functional — i.e. they do not depend
on any organic disease in the retina, or other portions of the visual
apparatus, but merely upon derangement of the functions of these
parts. Consequently, there are no ophthalmoscopic changes in the
fundus oculi.

In the following, the derangements of vision most liable to be
found in each condition will be pointed out, but here it is desirable
in the first instance to state them in a general way. Complete
blindness of one or both eyes may be found, but is rare ; a dimin-
ished, but fluctuating, acuteness of vision is more common, the effort
or desire to see well being often the signal for the acuteness of vision
to fall, and objects disappear from sight if looked at long. Attacks
of defective sight, too, may come on suddenly without any provoca-
tion, accompanied by positive scotomata, and may last for some
minutes. But the most remarkable, important, and characteristic
symptom is concentric contraction of the fields of vision. It is
almost always necessary, in order to ascertain the presence of this
symptom, to examine the fields with the perimeter — no rougher
method will answer — and it is important to use a test-object not
more than 5 mm. square. Concentric contraction of the fields is, we
know, a symptom in optic atrophy and in glaucoma ; but, while in
those diseases the contraction usually advances with more or less
deep re-entering angles directed towards the fixation point, in
nervous amblyopia the contraction is about equal in degree in each
meridian, and hence the seeing portion of the field which is left
presents a somewhat circular shape (Fig. 120). This shape of the
field with normal ophthalmoscopic appearances is pathognomonic
of the condition. The contraction may be but slight, or it may

CHAP. XIV.] NERVOUS AMBLYOPIA. 385

approach to within 10° or 5° of the fixation point. It is almost
invariably present in both eyes, but it is often more marked in one
eye than in the other.

Associated sometimes with this concentric contraction, and some-
times without it, is a phenomenon known as the fatigue field. It
consists in this, that if the test-object be brought from the periphery
towards the fixation point in each meridian successively, the out-
side limit of the field comes nearer to the fixation point on each
successive meridian examined, without regard to the part of the
field in which the examination is commenced. Or, if the test-
object be brought in the horizontal meridian from the periphery
on, say, the temporal side across the field until it disappears on
the nasal side, and the points of entrance and of exit noted, and
the object be immediately carried back on the same meridian until
it disappears on the nasal side, and the entrance and exit again
noted, and this manoeuvre repeated five or six times ; should
fatigue be present, it will be shown by the points of entrance and
exit coming nearer and nearer to the fixation point on each journey
— in short, the field is becoming more and more contracted. This
method of taking the field in these cases is useful, too, as showing
whether at the beginning there is any concentric contraction of the
field. These two modes of examination are practically the same ;
and the reason for the form of fields they are intended to bring
out is, that the longer in each case the examination is continued,
the more fatigued does the nervous visual apparatus (be it cerebral
centre, or retina, or both) become, and this exhaustion is most
marked in the periphery of the field. In the normal state, the
boundary of the field is not much affected by the length of the
examination.

In addition to contraction of the visual field, inversion of the
colour fields is often present, the field for red becoming the largest.
This sign may also sometimes be found in cases of cerebral
tumour.

Ring-form and island-like defects in various parts of the field,
which come and go, are recognised as functional defects, and cannot
be confused with the continuing central scotoma of toxic amblyopia
due to disease in the papillo-macular fibres. In addition to the
defective sight, or contraction of the fields, or fleeting scotomata,
there are often other eye-symptoms present, such as weakness of
25

386 DISEASES OF THE EYE. [chap. xiv.

accommodation, or of the internal recti, or some derangement of the
fifth or facial nerves.

While functional derangements of vision, as distinguished from
those due to organic disease, are what are here under consideration,
yet it is very necessary to state that visual defects due to organic
disease may sometimes be aggravated by functional blindness. In
tabes with optic atrophy, for instance, the contraction of the field
may become suddenly increased with the occurrence of some mental
worry or intercurrent general illness, and become restored again to
its former dimensions with the return to a calmer state of mind or to
improved health. In homonymous hemianopsia, as already men-
tioned, there is often a peripheral contraction in the seeing side of
the field, which can only be due to diminished functional activity in
the opposite side of the brain from that in which the disease is
situated.

In the three disorders of the nervous system mentioned, the
symptoms may, in a given case, remain confined to the nerves which
are associated with the various functions of the eye ; but this is
rare. It is more common to find also symptoms provided by the
derangement of functions in other parts of the nervous system.

Nervous Amblyopia in Neurasthenia.— School-children and those
of that age are very liable to become neurasthenic. They are brought
to the physician with the complaints that the sight is confused, that
print disappears as they look at it, that reading causes the eyes to
smart and run over water, and that it brings on headache. If the
patient be required to read aloud, he soon stops, complaining that
the words are running into each other, and the book is then brought
closer to the eyes ; then a few more words are read, and the book is
brought still closer, until, finally, it is nearly in contact with the
nose ; and then further attempts to see are made by twisting the
head about, turning the book towards the light, frowning, and so
on. Obviously what causes this difficulty in reading is a rapid
exhaustion of the accommodation. Insufficiency of convergence
is also often present, and would contribute to the difficulty of use for
near work. The eyes are often emmetropic, and the amplitude of
accommodation is normal. Examination of the fields may dis-
cover them to be concentrically contracted, and the fatigue field,
too, is frequently present. With these asthenic symptoms there are
often symptoms of exalted sensibility of the visual apparatus, such

CHAP. XIV.] NERVOUS AMBLYOPIA. 38'

as photopsiae (bright spots, coloured balls, glittering surfaces, etc.,
before the eyes), a prolonged continuance of the after-images of
objects, increased sensitiveness to daylight, and still more so to
artificial light, and visual hallucinations (heads, animals, passing
shadows, etc.). In the neurasthenia of school-children eye-symptoms
often predominate, but other nervous symptoms are nearly always
present, such as hallucinations of hearing, states of uncalled-for
joyous excitement, or of mental depression, or of irritability of
temper. Vertigo, a tendency to weep, some loss of memory, and
insomnia may all, or any, of them be present. The patellar reflex
is usually increased. Patches of diminished sensation may be found
here and there over the surface of the body, although completely
anfesthetic patches, or hemiansesthesia, are rare.

In school-children complaints of difficulty in reading suggest
malingering in many instances, but it is not wise to adopt this view
without good grounds for it. An examination of the fields may set
the question at rest, for neither the concentrically contracted field
nor the fatigue field can be malingered.

The neurasthenia of adults manifests itself, so far as eye-symp-
toms are concerned, less in the use for near work than is the case
with school-children. In them, moreover, the contraction of the
fields is usually slight, while the fatigue field is well marked. These
patients complain of unpleasant and painful sensations in and
around the eye, such as creeping sensations and boring pains in the
orbit, stabbings in the eyeball, a sensation as if the eye w^ere turned
round in the head, and uneasy feelings attending the motions of the
globe. The eye may be very painful on pressure at some one spot
without apparent cause ; and there are often uncomfortable sensa-
tions of cold, burning, or dryness under the lids. If there be an
error of refraction it is difficult to find glasses with which the patients
will be content, the bridge and wings of the frames annoy them with
their slight pressure, while the reflection of light from the margins
of the eye-pieces causes dazzling. The patients are very sensitive
to any bright light. The central acuteness of vision is usually
normal, but use of the eyes for near work causes headache, often in
the form of a hammering in the temples, or a sensation of pressure
on the vortex.

Treatment. — Tinted protection spectacles. Abstinence from use
of the eyes for near work. A general tonic treatment, including

388 DISEASES OF THE EYE. [chap. xiv.

cold sponge baths when they can be borne, bracing air, plenty of
exercise in the open air short of fatigue, early hours, and easily
digested diet. As regards drugs, strychnine and iron are those
from which most can be expected.

Nervous Amblyopia in Hysteria.— Nervous amblyopia, or ner-
vous asthenopia, in hysteria is often very similar to that in the
neurasthenia of school-children, except that the difficulty for near
work is even greater. Tonic blepharospasm and partial paralysis
of orbital muscles may accompany it. The blepharospasm may be
slight and give rise to a pseudo-ptosis which differs from the paralytic

Left Field. RightField.

20__

120 \

^ ^^ *^ V ^0 .* V , ^-r ., z^ ,. a^^ ^^^^^ ,:, ^, ^ ,,-*-^^^ ^ ,, ,^-^.

130 ^-n —

Fig. 120. — Case of Hysteria. Extreme and absolute contraction of
each field — the left more so than the right — for white. Owing to the
small dimensions of the fields the colour boundaries could not be
ascertained.

form of ptosis, in that the eyebrow is lowered instead of being raised
as in the latter. Spasm of convergence and of accommodation are
sometimes seen. The field of vision is commonly more contracted
in one eye than in the other, or the contraction may be very marked
in one field, while the other field is normal or nearly so. In neuras-
thenia the contraction is usually about equal in each eye. Inversion
of the colour fields is often present in hysterical amblyopia, so that
the field for red is wider than that for blue. Orientation is rendered
more difficult by the hysterical than by the neurasthenic field. A
high degree of blindness or even complete amaurosis may attack a
neurasthenic school-child for a few minutes ; but in hysteria such
attacks, which may occur in both eyes, but are usually confined to

CHAP. XIV.] NERVOUS AMBLYOPIA. 389

one eye, are likely to last for weeks, or months, or longer. In the
amblyopia of hysteria, we may find that an eye, which cannot see
moderately sized type, is enabled to do so by placing any plane glass
as spectacles before the eye. Such an occurrence does not mean
that the patient is malingering ; it shows, rather, that the
psychical inhibition to the function of sight in the eye has been
withdrawn by the suggestion provided by the spectacles.

With monocular amblyopia, or amaurosis, there is usually hemi-
aucesthesia of the same side of the body as the blind eye ; or, if
there be merely contraction of the fields, there is often hemi-
ansesthesia on the side of the most contracted field.

The pupils vary much in these cases, and even in one and the
same case from time to time. They may be normal, or wide and
immovable, contracted, or of different size in each eye, but they
usually react to light even though amaurosis be present.

Nervous Amblyopia in Traumatic Neurosis. One of the most
important and most constant of the symptoms of traumatic neurosis
is concentric contraction of the field of vision. Yet it is often absent,
and, when present, is not always sufficiently typical in form to enable
it to be utilised in the diagnosis. It is rarely so pronounced as
to interfere with orientation, and must be sought for with the peri-
meter to determine its presence. The boundaries for the colour-
fields are affected even more than that for white, and consequently
the tests for these boundaries may discover the contraction more
readily than examination of the boundary for white. The colour
boundaries are often inverted, but colour-blindness is seldom present.
The defect in the field is usually to be found in both eyes, and if
there be hemianaesthesia it is on the side of the most contracted
field. It is an important fact that the contraction of the field may
be the only derangement of sensation, either special or general.
The contraction is liable to continue for months or years, and to
become more marked for a time, as the result of any passing mental
disturbance. The fatigue field, too, is present in some cases of
traumatic neurosis.

As regards other ocular symptoms in traumatic neurosis : the
pupil-reflex is usually normal, but is occasionally wanting, and a
difference in size of the pupils may sometimes be noted ; paralyses
of orbital muscles are rare, but insufficiency of convergence is
not uncommon ; sensations of sparks, colours, and waviness before

390 DISEASES OF THE EYE. [chap. xtv.

the eyes are sometimes complained of ; photophobia, and sensa-
tions of dazzling with their resulting blepharospasm, may be present.
It is not desirable to rest content with one examination of the
held of vision which may prove negative in its result, for it is only
shown thereby that on that particular occasion the field was normal.
At a later period a defect may be discovered.

Part V.
VARIOUS FORMS OF AMBLYOPIA.

Transitory Hemianopsia, or Scintillating Scotoma.— This affec-
tion is characterised by (1) symmetrical defects in the fields of vision,
usually of the hemianopic type, and (2) vibrating or scintillating
luminous sensations, which after a short time disappear, and are
followed by an attack of (3) migraine which is often unilateral and
situated on the side opposite to the hemianopsia. In fact, the visual
troubles belong to the symptoms of migraine.

The scintillations and defects in the fields, either of which may
occur first, commence over a small area, generally near the centre
of the field, and gradually widen out into a semicircle or horseshoe
with the concavity towards the centre ; the flashing increases in
intensity, and often assumes a zigzag shape, like fortifications, at
the periphery of the defect in the field. This defect may exist as
symmetrical scotomata, complete or partial homonymous hemi-
anopsia, or even altitudinal hemianopsia. In some cases the scintil-
lation may be absent, while in others the attack of migraine does
not follow. The ocular symptoms, which last for a period varying
from a few minutes to half an hour, are not accompanied by any
changes in the fundus oculi, and nearly always end in complete
recovery, but a few cases have been recorded in which the hemi-
anopsia persisted. Vertigo, nausea, or sickness, and even slight
aphasia sometimes accompany the headache. The Ophthalmo-
scopic appearances are normal.

This afjfection occurs most frequently in intellectually active
individuals ; fatigue, long reading, and hunger have been known
to bring on attacks. With advancing years the attacks tend to
diminish. The symptoms are pro])a])ly due to disturbances of the
circulation in the occipital lobe.

CHAP. XIV.] VARIOUS FORMS OF AMBLYOPIA. 391

Treatment should be directed to the cause of the migraine.
Lying with the head low, or stimulation of the circulation by
wine or nitro-glycerine sometimes cuts short an attack. Errors of
refraction, or any heterophoria must be corrected.

Congenital Amblyopia. — This condition is not very uncommon.
Ophthalmologists, in the course of their practice, meet with persons
in whom the vision of each eye is below the normal standard, even
with perfect correction of any error in refraction, and who declare
that they never have seen better, and that their sight is not getting
worse. Still more common is congenital amblyopia in one eye
even without strabismus. It is sometimes hereditary. As a rule
the field of vision and the colour- vision are normal, but cases occur
in which there is contraction of the field, with defective colour-
sight or a central scotoma. The Ophthalmoscopic Appearances
are normal.

Amblyopia during Pregnancy.— The disturbances of vision which
occur during pregnancy are seldom functional, with the exception of
occasional hysterical cases. They are for the most part due to
uraemia. But occasionally cases are seen in which a functional
amblyopia special to the period of pregnancy occurs. Whether
this is due to toxic efiects, or to disturbances of nutrition, or to
disturbances of circulation has not been determined. Recovery
takes place after the birth, and sometimes even before it.

Reflex Amblyopia is said to have been observed, and chiefly in con-
nection with irritation of the fifth pair, especially of its dental branches.
Carious molar teeth are reputed to be its frequent cause, usually with
severe toothache, but sometimes without it. The defect of vision may
be confined to the side of the carious tooth, and is nearly always most
marked on that side. It is said that it may be of extreine degree, vision
being reduced even to the merest perception of light. It is doubtful
whether the amblyopia in these cases is truly reflex.

More generally recognised than amblyojDia, as the result of toothache,
are : hypersesthesia of the retina, photophobia, subjective sensations of
light, and diminution in the amplitude of accommodation.

All these symptoms, even amblyopia of the severest type, disappear
when the dental affection is relieved.

Many cases are on record in which wounds of the supra-orbital nerve
were looked on as the cause of amblyopia or of amaurosis ; but it is by no
means certain that an ophthalmoscopic examination would not have
afforded another explanation in many of these cases. Yet, even nowa-
days, many hold that wounds of the supra-orbital region can produce
amblyopia, as cases are said to have been cured by division of the nerve
involved in a cicatrix that was tender on pressure.

392 DISEASES OF THE EYE. [chap. xiv.

The Ophthalmoscopic Appearances in reflex amblyopia are normal.

Night-blindness.— This is a well-recognised symptom of the
disease known as Retinitis Pigmentosa. We have observed an
instance of congenital night-blindness in five members of a family
of ten children without ophthalmoscopic signs.

But the condition to be considered here is Acute, or Idiopathic,
Night-blindness.

The patients can see well in good daylight ; but on a very dull
day, or in the dusk of evening, or by indifferent artificial light, their
vision sinks very much more than that of persons with normal eyes.
They are then unable to see small objects, w^hich are quite plain
to other people, and in a still worse light they fail even to recognise
large objects visible to every one else. This peculiar visual defect
is due to imperfect adaptation power of the retina, and not to
defective light-sense, as is sometimes stated.

Conjunctivitis and xerosis of the conjunctiva (p. 96) are often
present in acute night-blindness. Some observers have found
micrococci and bacilli in the conjunctiva in these cases, and have
regarded these organisms as the cause of the conjunctival affection.
It seems now more probable that they are merely secondary to the
xerosis.

The connection between night-blindness and xerosis conjunctivae
remains to be explained ; but it is likely that they are both results
of one cause.

Acute night-blindness is often the result of long-continued daz-
zling by very bright sunlight, or of lengthened exposure to bright
firehght (e.g. in foundries), and it is probable that in many, if not
in most, instances of this affection, defective nutrition of the system,
or, according to some, deficiency in the fat content of the blood, plays
the chief role in rendering the patients liable to it. In scorbutus,
acute night-blindness has been frequently seen, when the patients
have been exposed to strong glares of sunlight. It is common in
an epidemic form in Russia during Lent.

Treatment consists in protection from light — in short, in complete
darkness for a time — and then gradual return to ordinary daylight ;
while the system is to be strengthened by careful dietary and suit-
able tonic medicines, especially cod-liver oil or eel oil.

Uraemic Amblyopia. — This is most commonly seen in connection
with the nephritis of pregnancy and scarlatina, but may occur in

CHAP. XIV.] VARIOUS FOBMS OF AMBLYOPIA 393

any case of iireemic poisoning. It is met with in the acute forms of
nephritis, in which albuminuric retinitis is not so liable to occur.
The blindness is usually absolute, and may come on suddenly, or
with a short previous stage of dimness of vision. It lasts from
twelve hours to two or three days, and may recover completely,
but in some cases a central scotoma remains.

The O'pJithahnosco'pic Appearances are negative.

Treatment can only be directed to the general condition.

The Prognosis for vision is good, as it always recovers if the
patient's life be spared.

Pretended Amaurosis. — Malingerers rarely simulate total blind-
ness of both eyes, and such cases can often only be detected by con-
stant observation of their actions.

The presence of pupillary reflex is not complete proof, although
very strong evidence, that the patient sees, for it would be compatible
with a cortical lesion causing total loss of sight.

The crossed diplopia test {vide infra) may be employed to detect
malingerers of this class ; for if both eyes see, the one armed with
the prism will rotate inwards for the sake of single vision, while
if both eyes be blind, no such motion will take place. Again, if
the malingerer's own hand be placed in various positions, and he
be asked to look at it, he w411 in all probability look in some other
direction ; whereas a truly blind man usually makes a fair attempt
at directing his eyes towards his own hand.

Pretended monocular amaurosis can generally be detected by
the Diplopia Test. If the malingerer be made to look, w^th both
eyes open, at a lighted candle placed some feet off, while a prism of
not less than 5° or 6°, with its base downwards, is held before the
admittedly good eye, he will say he sees two images of the light
one over the other. Were he blind of one eye he would not see
two images.

Another method — the Crossed Diplopia Test — consists in holding
a prism of some 10° or 12° with its base outwards before the pre-
tended blind eye, when, if it sees, it will make a rotation inwards for
the sake of single vision, an effort which a blind eye w^ould not make.

Alfred Grgefe's Method.— In this test the pretended blind eye is
covered with the surgeon's hand from behind the patient, while with
the other hand a prism (about 10°), without a metal rim, is held
base down before the good eye, so that its edge may pass horizontally

394 DISEASES OF THE EYE. [chap. xiv.

across the centre of tlie pupil. Moiiociilar double vision results, as
the rays pass through the upper part of the pupil normally, while
through the lower part of it they are refracted downwards by the
prism. The double images stand over each other. If now the hand
which excludes the pretended blind eye be rapidly removed, while
at the same moment the prism is moved upwards, so that the entire
pupil is covered by it, a malingerer will still see double images stand-
ing one over the other ; but now the diplopia must be binocular.

Harlan's Test consists in placing a trial frame on the patient's
nose wdth a very high + lens — say -\- li D — opposite the good eye,
by which means it is excluded from distant vision, and a plane glass
— or a 0'25 D convex or concave lens, w^hich of course w^ould not
materially interfere wdth its distant vision — opposite the pretended
blind eye. The patient then, believing there is much the same kind
of glass before each eye, will read the test-types ; and if it be now^
desired to expose the deception, the pretended blind eye is excluded
from sight, and the malingerer w^ill then be unable to read the test-
types.

Snellen's Coloured Types may also be used for this purpose.
These types are printed in green and red. If a person be really blind
of one eye, he will, of course, see both the green and the red letters
W'ith the good eye. But if a green glass be held before the good eye,
the rays from the red letters will be excluded, and he wall now only
see the green letters ; or with a red glass the red letters alone will
be seen. A malingerer may be detected by holding before his ad-
mittedly good eye a green glass ; and if he now^ still see the red
letters, it must be that he does so wdth the so-called blind eye. A
good modification of this test is Haselberg's test types, of which the
letters are composed of black and red portions. The diploscope
and diaphragm tests (chap, xvii.) are also useful.

It is well to have this variety of tests, in order that they may be
used to corroborate each other.

Erythropsia {(pvOpos, red) — Red Vision. ^lany cases of this remark-
able affection have been observed ; indeed, it will have come under
the notice of nearly every ophthalmic surgeon of any experience. The
majority of the cases have been subjects of successfvil cataract operations,
whilst the remainder have possessed normal eyes. It is generally the
result of prolonged exposure to the light, especially with dilated pupils. In
some cases the red vision remains only a few minutes, and does not again
return ; Mhilst in others it appears every day for a short time, for weeks

CHAP. XIV.] VARIOUS FORMS OF AMBLYOPIA. 395

or months ; and, again, in others it continues for several days, and then
disappears for good or recurs at intervals. In the aphakic cases it does
not usually appear for weeks or months after the removal of the cataract,
and the interval may be as long as two years. During the attacks the
patients see all objects of a deep red colour, and occasionally of a purple
or violet hue. In no instance is the acuteness of vision affected either
during or after the attacks.

A quite satisfactory explanation for the affection has not yet been
offered. Possibly it is due to over-excitation of the visual nervous appar-
atus — it may be of the visual centre, or of the retina — caused by exposure
of the eye to light which is rich in ultra-violet rays, as in high mountain
altitudes, along with other favouring circumstances, especially general
over-excitement of the body or mind. The normal crystalline lens absorbs
the greater part of the ultra-violet rays which are present in the daylight
at ordinary altitudes. Consequently the retina of an eye which has been
operated on for cataract is deprived of this protection, and is liable to the
irritation caused by these rays.

Treatment seems to have but little effect. Protection of the eyes from
light has not been of use. Bromide of potassium internally seems to
have done some good in those cases where it was tried.

CHAPTER XV.
ELEMENTARY OPTICS.

§ 1. The light from a luminous point travels in all directions in diverging
straight lines which are called rays. The angle between the outermost
rays which pass through an aperture (A B, Fig. 121), or fall on a given
surface, is the measure of the divergence of the rays. This divergence
diminishes as the distance of the luminous point, from the surface on which
the light falls, increases until it finally becomes so small that the rays
may be considered to be parallel. In a strict mathematical sense, rays
can only be parallel .when the luminous point from which they come is
at an infinite distance ; but, in ophthalmological practice, rays proceeding

from any point at a dis-
tance of 6 metres, or more,
from the eye may be re-
garded as parallel when
they reach the pupil.
Under natural conditions,
rays entering the eye are
either divergent (objects
nearer the pupil than 6 m.)
or parallel ; but they are
never convergent, unless
rendered so by artificial
means (lenses, mirrors).

§ 2. When light falls
on an opaque object, some
of the rays are absorbed, some are reflected in an irregular or diffuse
manner, rendering the object visible, while others are regularly reflected
according to the amount of polish on the surface of the object, but none
pass through it. When the object is transparent, the majority of the rays
pass through, but are bent or refracted if the velocity of the light be
diminished in its passage through the object — that is to say, if the optical
density of the latter be greater than that of the surrounding medium.

§ 3. Refraction, then, is the deviation which a ray of light undergoes
when it passes from one homogeneous transparent medium into another
of different density. The only rays which are not refracted are those
perpendicular to the surface (A B, Fig. 122). All others are deviated to-
wards the perpendicular when passing from a rarer into a denser medium,
and away from the perpendicular when travelling in tlie opposite direction.

396

Fig. 121 . — The rays f rom D, which is further
from A B than C, have a smaller angle of
divergence. The parallel rays, E E, are sup-
posed to come from a point infinitely distant.

CHAP. XV.

ELEMENTARY OPTICS.

397

In Fig. 122 the incident ray, I H, travelling from the rarer medium (air)
into the denser medium (glass), is bent towards the perpendicular, P,
in the direction H R, and would continue in this path as long as it remained
in the denser medium ; i is the angle of incidence and r the angle of re-
fraction. If the ray R H were to pass back in the opposite direction
from the glass into air, it would be deviated away from the perpendicular,
in the direction H T. The path of the ray, therefore, is the same in either
direction.

§ 4. Index of Refraction. — The more optically dense a medium is,
the greater is its refractive power. The relative refractive power of a
given substance is called the index of refraction of the substance, air
being generally taken as the unit. A medium, therefore, having a greater
density than air will have, as index, a number greater than unity ; the
index of crown glass, for instance, is To. The cornea and the vitreous
humour have the same index as water, namely r33, while that of the
crystalline lens, as a whole, is r43.
The refractive power depends on the
difference between the indices of the
two media ; for example, in the eye
the cornea has a greater effect than
the lens, although it has a lower re-
fractive index than the latter, because
the difference between air and the
cornea is greater than that between
the media (aqueous and vitreous) and
the lens which lies in them.

§ 5. Plane Parallel Surfaces (Plane
Glass) bounding a transparent medium
cause merely a lateral displacement of
the rays without changing their direc-
tion, if the first and last media are
the same. In Fig. 122, C D F G may
be taken to represent a piece of glass
with parallel sides C D and F G, with

air on each side. When the emergent ray, R E, passes out again into the
air it is refracted away from the perpendicular, P', and as the angles
i and r' are equal, and the perpendiculars P and P' are parallel, the ray
E R is parallel to its original path I H, and suffers only a lateral dis-
placement, which increases with the thickness of the plate. But the rela-
tive direction of the rays is not changed ; they retain the parallelism,
divergence, or convergence, which they possessed before their passage
through the plate ; hence no images are formed by plane glass, and ob-
jects seen through it are unaltered in size and shape.

Fig. 122. — Refraction at a
plane surface. The siu'faces C D
and F G being parallel, the
emergent R E is parallel to the
incident ray I H.

Prisms.
§ 6. Prisms are refracting media limited by plane surfaces which
are inclined at angle, as in Fig. 123. The thin edge is called the

398

DISEASESI^OF THE EYE.

[chap. XV

iVpex, a is the Refracting Angle, wliile the thick part'opposite the
apex is the Base. In passing through a prism a ray of light under-

FiG. 123. — Refraction by a
prism. The rays from O are
displaced towards the base, but
O appears to an observer at R to
be displaced towards the apex.

Fig. 124. — Showing
parallelism or diverg-
ence of rays unaltered
by their passage
through a prism.

Fig. 12

goes a double refraction towards the base. The ray is deflected
towards the perpendicular on entering the prism, and away from it
on passing into the air at the side B A, the deviation being towards
the base in each case.

An obiect seen through a prism seems to be displaced towards the
apex ; for example, an eye placed at R receives the ray E R coming
from 0, and imagines it to be at 0' in the prolongation of R E.
The deviation which the ray has undergone is shown by the angle
d (angle of deviation). In prisms made of crown glass, with an
index of refraction of 1*5, the angle of deviation is equal to half the
angle of the prisms. Fig. 124 shows that, as in plane glass, the rela-
tion of the rays to each other is unaltered
in their passage through a prism.

§ 7. Numbering of Prisms.— Prisms
are numbered according to the size of
the refracting angle {a, Fig. 123), which is
expressed in degrees ; we speak of prisms
of r, 2°, etc.

CT
-One centrad =^5-.
R

AT =

One prism dioptre -:^

1 R

1 cm.

100 cm.'

This method ut numeration is not quite

accurate, because the deviation depends, not

only on the angle of the prisms, but also on

the refractive index of the glass composing

it ; hence, two prisms having the same number will not produce the

same amount of deviation, or be of the same strength, if the kinds of

CHAP. XV,]

ELEMENTARY OPTICS.

399

glass of which they are made have different refractive powers. It has,
therefore, been proposed to number them according to the angle of
deviation (d, Fig. 123), expressed either in Centrads or in Prism-Dioptres, a
centrad being a deviation {d, Fig. 125), the arc (C T) of which is ^}jy of the
radius, while in the prism-dioptre it is the tangent (A T) which is the -f^jf
of the radius (Fig. 125). The three methods are, however, equivalent
for all practical purposes. The simplest plan would be to indicate the
deviation, and not the angle of the prism, in degrees.

§ 8. Recognition of a Prism and the Base-apex Line.— Prisms

used in ophthalmic practice are usually cut round for convenience
of placing in trial frames, but the thick base and thin apex are

Fig. 126.— Prism hori-
zontal, vertical line only
displaced.

Fig. 127.— Prism held
obliquely, both vertical and
horizontal lines displaced.

sufficient to distinguish them from lenses or plane glass. In weak
prisms this is not so evident, but they can always be recognised by
the displacement which they cause when an object is seen through
them, by quickly putting the prism up before one eye, the other
being closed, or if the prism be rotated before the eye, an object seen
through it will be observed to move in a circle, following the dis-
placement of the apex. Figs. 126 and 127 show a simple method of
selecting the displacement, and at the same time of ascertaining the
exact position of the apex and base. The prism is held at a short
distance from the eye opposite two crossed lines, vertical and hori-
zontal (the bars of a window-sash, say), so that they can be seen
outside the edge of the glass as well as through it. If, as in Fig. 126,
the apex and base, A, and B, are exactly horizontal, then the portion

400

DISEASES OF THE EYE.

[chap. XV

of the vertical line C D seen through the glass will alone be dis-
placed towards the apex ; but if the prism be oblique both lines
will be displaced as in Fig. 127.

§ 9. Effect of a Prism on Binocular Vision.— When a prism is
placed before one eye, both eyes being open, the immediate effect is
to cause double vision or diplopia, which either persists, or is over-
come by an effort of one of the orbital muscles. In Fig. 128, the
image of the object, 0, falls on the macula lutea, M, in the left eye
(L), but instead of falling on the macula, M, in the right eye (R) it is
displaced by the prism, towards the base of which it is refracted to

a point B on the retina, which is
not physiologically identical with
M in the left eye, and now
appears to the right eye to be at
0', in the prolongation of B P,
and the patient sees two images,
one with each eye. An uncon-
scious effort is then made by
the patient to bring the macula,
M, into the position B. This is
accomplished by the action of
the Ext. Rectus (R E), and thus
single vision is again obtained.
If desired, by increasing the
strength of the prism until the
diplopia can no longer be overcome, the strength of the muscle,
in this instance the Ext. Rectus, can be estimated. It will be
observed also, that when, in order to correct the diplopia, the axis
of the eye has moved into the position P B, the convergence of the
eyes is diminished, and therefore the effort of the internal rectus
muscle must to a certain extent be relieved. From this it follows,
that the muscle towards the apex of the prism is brought into
action, while the muscle towards the base is relieved. The rotatory
prism, composed of two prisms of equal strength, in contact, and
rotating in opposite directions, is a useful instrument for measuring
purposes, as by its aid values of from 0° up to the strength of both
prisms combined can be obtained gradually. Maddox's double
prism is also very convenient for producing diplopia (see Latent
Deviations, chap. xvii.).

Fig. 128. — Binocular diplopia pro
duced by a prism.

CHAP. XV.

ELEMENTARY OPTICS.

401

§ 10. Uses of Prisms. — 1. By the production of diplopia, prisms
can be used, {a) to test the strength of muscles, {h) to detect latent
deviations or insufficiencies of muscles, (c) to strengthen weak muscles
by exercise, {d) to test binocular vision, (e) to detect feigned blind-
ness of one eye. 2. For the purpose of correcting or measuring the
diplopia in paralysis, or insufficiencies of orbital muscles.

§ 11. Prescribing of Prisms. — In practice prisms of more than
four degrees can rarely be worn by patients, owing chiefly to the
weight and colour effects of higher numbers. The position of a prism
placed before an eye is indicated by reference to its base, e.g. Pr. 3°
base up, down, in, or out, as the case may be.

Lenses.

§ 12. A lens is a portion of a transparent refracting medium
bounded by two surfaces, one or both of which are curved. It

Fig. 1 29. — Convergent
effect of a convex or +
lens. F, principal focus.

Fig. 130. — Divergent
effect of a concave or —
lens. F, principal focus.

may be spherical, or cylindrical, or it may be compound — that is to
say, spherical on one surface and cylindrical on the other.

§ 13. Spherical Lenses are bounded by spherical surfaces, and
therefore their action is the same in all meridians ; they are either
convex or concave. Convex spherical lenses may be regarded as
composed of prisms with their bases together (Fig. 129) and are
thickest in the centre. They converge parallel rays of light, and
bring them to a point or focus. Concave lenses, on the other hand,
are like prisms with their apices together (Fig. 130), and are thinnest
in the centre. They cause parallel rays of light to diverge. Convex
lenses are positive, and are indicated by the sign + (plus). Concave
lenses are negative, and marked with the sign — (minus). The
26

40:

DISEASES OF THE EYE.

[cHAr. xv.

former placed in front of the eye add to its refractive power, the
latter diminish it. Fig. 131 shows the different kinds of spherical

Convex or -i-.

Concave or —

Plano-convex

^ ^

r^-^ 1 Pinnn-concnvp.

Bl convex

<c_>

^ ^->J Biconcave

Con V ex m cms ciis

"^=r ^•

^^====::^ Concave meniscus.

iperiscopicieris)

pertscoptc lens)

Fic;, 131. — Different forms of spherical lenses.

lenses in use. In the convex meniscus, the convex surface has
a shorter radius of curvature than the concave ; whereas in the con-
cave meniscus, the concave surface has the smaller curve. Meniscus
lenses are also called periscopic (^epi, around', o-Koirdv, to look),
because (with the concave surface towards the eye) they produce
less distortion towards their edges, and consequently permit a
greater excursion of the eye.

§ 14. Axes of Spherical Lenses. — The Principal Axis of a spherical
lens (P A, Fig. 132) is the line joining the centres of curvature of the
surfaces, and the point in the centre of the lens on the principal
axis is known as the Optical Centre. Any ray passing through the

optical centre, except along
the principal axis, is called
a Secondary Axis, and it
emerges parallel to its origi-
nal direction (N E is parallel
to S S'). In thin lenses the
slight displacement may be
neglected, and the second-
ary axes may be considered
to pass through the optical
centre without any devia-
tion. These statements
apply to both convex and concave lenses.

§ 15. Principal Focus of Convex Spherical Lenses.— The point to
which parallel rays of light converge after passage through a convex

Fig.

132. — Primary and secondary axes
of a lens.

CHAP. XV.

ELEMENTARY OPTICS.

403

Fig. 133. — Principal focus
(P F) and focal length of a
lens ,

The stronger

the lens the

lens is called the Principal Focus of the lens, and the distance of

this point from the lens is its focal length (Fig. 133). Rays of light

diverging from the principal focus

pass out parallel on the other side

of the lens. Rays {a c, Fig. 133),

parallel to the principal axis, have

their focus on this axis, while those

which are parallel to a secondary

axis (A 8, Fig. 134) are brought to a

focus on the secondary axis at a

point (S), where it cuts the perpen-
dicular line passing through the

principal focus (principal focal plane).

more the rays are refracted, and therefore the shorter is the focal

length (Fig. 135.)

§ 16. Conjugate Foci are foci
which are so related that rays from
one of them pass to the other and
vice versa. For instance, the con-
jugate focus of parallel rays (or in-
finity) is the principal focus, and
the latter is again the conjugate
focus of infinity.

§ 17. Real, or Positive, Conjugate
Focus of a Convex Lens. — We have
now to consider what happens to

rays which diverge from points on either side of the principal

focus ; namely, points farther from, or nearer to, the lens than the

principal focus. In Fig. 136 the rays from

the point 1 farther from the lens than the

principal focus F, converge to 1', bej^ond

F, on the other side of the lens, and form

an image there, which is real and can be

received on a screen. When the point

from which the rays diverge approaches

nearer to F, say at 2, then the conjugate

focus moves farther away to 2\ until,

when the. point reaches the principal focus F, the conjugate focus

has moved away to infinity and the rays are parallel. It will be

Fig. 134.— Rays A and B,
parallel to the secondary axis
A S, unite in the focal plane
F P at S.

Fig. 1 35. — The stronger
lens (2) has a shorter
focus, F 2.

404

DISEASES OF THE EYE.

[chap. XV.

noticed that in this rase the conjugate foci are on opposite sides of
the lens, but that thev move in tlie same direction.

Fig. 130.

or positive, conjugate foci of a convex lens.

Fig. 137. — Virtual, ornegative, conjugate
foci of a convex lens.

§ 18. Virtual, or Negative, Focus of a Convex Lens.— When rays
proceed from a point nearer to the lens than the principal focus P\
the angle of divergence being greater than at F. the lens is not
sufficiently strong even to render them parallel, and they therefore

continue to diverge after
their passage through the
lens, but not so much as
before. In Fig. 137. the
rays coming from P, inter-
nal to the principal focus,
F, are rendered by their
passage through the -lens,
L, less divergent than be-
fore ; but, being divergent, they cannot come to a focus. To
an observer at C, however, looking through the lens, the rays A
and B would seem to come from a point P', in the direction of
their prolongation. P' is the conjugate focus of P, but it is virtual
as opposed to real, and is negative, or on the same side of the lens
as P. If we consider the rays as
travelling in the opposite direc-
tion, A and B with a convergence
towards P' will be focussed at P.

§ 19. Foci of Concave Spherical
Lenses. — A concave lens renders
parallel rays divergent. In Fig. 138,
rays A and B, parallel to the

principal axis P X, diverge as if they came from F, which is the
principal focus of the lens. Kays from a near point will be rendered
still more divergent, and will appear to proceed from a point still

Fio. 138. — Principal focus of a
concave lens.

CHAP. XV.]

ELEMENTARY OPTICS.

405

closer to the lens than the principal focus, F ; but, in all cases,
the conjugate focus will be apparent or virtual, and also negative,
or on the same side of the lens as the point of light. Convergent
rays are rendered parallel by a concave lens if they converge to-
wards the principal focus on the other side of the lens, and divergent
if the point towards which they converge is farther from the lens
than the principal focus. They still remain convergent, but less so
than before, if the point towards which they converge is closer to
the lens than the principal focus.

§ 20. Images formed by Spherical Lenses consist of foci each of
which corresponds with a point in tlie object, and of which it is the con-
jugate focus. The image is real when the rays forming it actually meet
and can be received on a screen ; it is virtual when it does not in reality
exist, but is formed by the imaginary backward prolongation of the rays,
and can only be seen by looking through the lens.

Fig. 139. — Image of a given point O formed by a convex lens.

§ 21. Method of finding the Position and Size of an Image formed by
a Spherical Lens. — In order to find the position of the image of a point,
say of O, Fig. 139, formed by a lens, first draw the secondary axis O I,
which passes through the optical centre without deviation. The image
will be formed on this axis at a point where the other rays proceeding
from O intersect it. Two other rays (the paths of which are known)
can be utilised : O A parallel to the principal axis will pass through the
principal focus Fo, and the image of O will be at I, where A I meets O I,
or I can be found by means of the ray O C, which passes through the
principal focus, Fi, and therefore becomes parallel to the principal axis,
taking the direction C I. In the following examples, the ray O A will
be used.

§ 22. Real Inverted Image formed by a Convex Lens. — When an
object is farther from the lens than the principal focus, an inverted image
is formed on the opposite side of the lens, as in Fig. 140, and the image is
equal to the object A C, and at the same distance from the lens, if the object
be at twice the focal distance from the lens. The image is larger if the
object be closer than 2F (e d is the image of D E), and smaller if it be
farther than 2F (D E is the image ii e d be the object). The closer the

40G

DISEASES OF THE EYE.

[chap. XV.

object is to the principal focus, the larger the image. It is in this way that
the image is produced in the indirect metliod of ophtlialmoscopy.

§ 23. Virtual, Erect, and Magnified Image formed by a Convex Lens.
When the object, C D (Fig. 141) is closer to the lens than the principal
focus Fi, an erect, magnified virtual image, c d, can be seen on looking
at the object through the lens. As the object approaches the lens, say
to N P, the image, n p, becomes smaller ; in other words, the virtual,

Fig. 140. — Real inverted image formed by a convex lens when the
object is farther from the lens than the principal focus.

like the real inverted image, increases in size the nearer the object is to
Fi. It is in this way that a convex lens is used as a magnifying glass.

Fig. 141. — Virtual erect and magnified image formed by a convex
lens, when the object is closer to the lens than the principal focus.

§ 24. Images formed by Concave Lenses are always erect, virtual and
diminished. The nearer the object is to the lens the larger the image.
In Fig. 142 the point c or image of C is found at the intersection of S R
(prolonged back to the principal focus, F) with the secondary axis COX,
and d e is the image of D E.

§ 25. Optical Defects of Lenses. — 1. Spherical Aberration. In
§ 15 it is stated that parallel rays after passing through a lens unite
in one point at the principal focus. Now this is practically the case,
if only a small area of the lens, near the axis, be utilised, say, by

CHAP. XV.] ELEMENTARY OPTICS. 407

means of a ' stop ' or diaphragm, but as more of the periphery of
the lens is taken in, the rays become increasingly refracted, and

Fig, 142. — Virtual erect and diminished imago formed
by a concave lens.

cut the axis correspondingly nearer to the lens (Fig. 143). Hence
when a larger portion of the lens is used, the image is rendered
indistinct. Spherical aberra-
tion is present in the eye,
although to a certain extent
corrected by contraction of
the pupil.

2. Chromatic Aberration.
— The spectral colours, of
which white light is com- Fig. 143.

posed, are refracted in differ-
ent degrees by a lens, the red rays being the least and the violet
the most refrangible. This tends to give a coloured border to
the images formed by the lens. This phenomenon is known as
chromatic aberration. It can be corrected by making a compound
lens of two kinds of glass having different colour dispersing powers.
Such a correction is necessary in many optical instruments, but
it is not required for spectacles in which the chromatic aberration
is not noticeable. Its presence in the eye, however, can be easily
demonstrated.

§ 26. Cylindrical Lenses.— A lead pencil is a good example of
a cylinder, the lead running down the centre being its axis. Any
lines on the surface, parallel to the axis, are straight lines, whereas
sections at right angles to the axis are always curved. If a slice
were taken off the surface of the pencil, in the direction of its length
or axis, and a round piece cut out of it, it would represent a convex
cylindrical lens. A cast of the surface of the pencil would form a

408 DISEASES OF THE EYE. [chap. xv.

concave cylinder. Cylinders only act in the direction of their cur-
vature — that is to say, at right angles to the axis. A cylinder
has no effect in tlie direction of its axis. Rays entering in the plane
of the axis are not refracted (Fig. 144, a), and rays entering in any
plane parallel to the axis (Fig. 144, h) are merely bent towards the
axis, but suffer no deviation in the direction of the axis — that is to

Fig. 144. — Refraction through a convex cylinder. F, the
principal focus, is really ajine parallel to the axis.

say, vertically in Fig. 144. On the other hand, rays in a plane at
right angles to the axis, meeting the curved surface, are made to
converge or diverge, according as the cylinder is convex or concave.
(Horizontal plane in Figs. 144 and 145.) The focus of a cylinder
therefore is a line parallel to the axis, and no image is formed.

The position of a cylinder placed before the eye is indicated by
the degree of inclination of its axis to the vertical or horizontal.
The axis of the cylindrical lenses used in trial-cases is shown by
two slight scratches at the edge, or by two muffed portions parallel
to the axis.

§ 27. Sphero- Cylindrical and Toric Lenses. — When it is necessary
to combine a splierical with a, cylindrical lens, the segment of the
sphere is usually ground on one surface of the glass and the cylinder
on the other, but in toric lenses the spherical and cylindrical effect
is produced on one surface. The nature of the surface then re-
sembles that of a bicycle tyre, the length of the tyre having a flatter
curve than the breadth.

CHAP. XV.] ELEMENTARY OPTICS. 409

§ 28. Numbering of Lenses. — The lenses in trial-cases and in
spectacles are numbered according to the metric system.

A lens of one metre focal length is adopted as the Dioptric Unit
or unit of refractive power, and is called a Dioptre (ID). The greater
the strength or refractive power of a lens, the higher will be its
number, and the shorter will be its focal length (Fig. 135). Lenses

Fig. 145. — Refraction through a concave cylinder.

of 2 D and 4 D are twice and four times as strong, respectively,
as a lens of 1 D, and their focal length will be inversely, J and J of
the focal length of the 1 D lens, that is to say '^■^ and ^^, or expressed
in centimetres (1 metre = 100 centimetres), if^ = 50 cm., and ^J^
= 25 cm.

If, therefore, it be required to ascertain the focal length of a
given lens, 100 must be divided by the dioptric number of the lens,
and the answer will give the focal length in centimetres. For ex-
ample, the focal length of a lens of 5 D is i"- = 20 cm.

If the focal length of the lens be known, and it be desired to
ascertain its dioptric number, we find it by dividing 100 cm. by the
focal length. For example, if the focal length be 33 cm., then

Lenses of less than 1 D have of course decimal fractions for their
numbers— e..^. 075, 0-5, and 0-25. The focal length of O'S D is i^
= 200 cm. = 2 metres. Cylindrical lenses are numbered in the same
way as sphericals. The strength of two lenses in contact is practi-
cally equal to the sum of their numbers, if of the same kind, and to

410

DISEASES OF THE EYE.

the difference of their numbers if of the opposite kind — c.(j. -\
lens combined witli — 1 D lens equals a + lens of 3 D.

[chap, XV.

4 1)

Fig. 140. — Apparent nioveuieiit,
in the opposite direction, pro-
duced by displacement of a
convex lens. In position 2,
O B is deviated towards the
base of the prism to D, and
OisseenatO'(§ 6).

Fig. 147. — Apparent movement,
in same direction, produced
by displacement of a concave
lens. In position 2 the
prism is base up, O B is
deviated to D, and O seems
to be at O'.

§ 29. Recognition of Spherical Lenses. — If a spherical lens be
moved before the eye, when looking at an object through it, the
object will seem to move in the opposite dii'ection in the case of a
convex lens, and in the same direction if the lens be concave. This
is due to the prismatic action of the lenses (Figs. 146 and 147), and
occurs equally in all diameters.

§ 30. Recognition of Cylindrical Lenses and of the Position
of the Axis. — Cylinders act in the manner described above for spheri-
cal lenses, but only in the direction at right angles to the axis. Fur-
ther, if a cylinder be rotated while an object is
viewed through it, it produce a distortion,
when the axis is oblique with regard to the
chief lines of the object. The effect is best seen
if a rectangular object be selected, the angles of
which are then no longer right or equal. This
is noticeable even when the cylinder is com-
bined with a spherical lens.

The simplest plan is to look at a vertical

line through the glass, and if the axis of the

cylinder be either vertical or horizontal, the portion of the line

seen through the glass appears to be continuous with that outside

it, whereas if the axis be oblique, as in Fig. 148, the portion

Axis ^ -.

CHAP. XV.

ELEMENTARY OPTICS.

411

Fig. 149.

seen through the lens becomes twisted into the position a h.
Maddox's axis-finder, Fig. 149, is based on this principle. The
spectacle frame is placed in a
groove on the top of the instru-
ment, and is held there, while both
are tilted round until the line ap-
pears continuous as at A, Fig. 149 ;
the pendulum, P, then indicates
on the graduated arc the position
of the axis, or the direction at
right angles to it. The axis can
also be found by the lens measurer.
*§ 31. To find the Numljer of
a Lens it is only necessary to
neutralise it with a lens of the
opposite kind taken from the trial-
case. The two lenses are held in
contact and moved together, while

the apparent motion of an object (§ 29) as seen through them is
noted, the lens which stops all movement giving the required number.
Or it can be ascertained more rapidly by the Geneva lens measurer,
Fig. 150. The three points, a, b, c, the central one, h, of which
is movable, are applied to the surface of the lens, and the corres-
ponding number is indicated by the pointer on the dial. Both
surfaces of the lens must of course be
measured. The position of the axis of a
cylinder is also easily found by this instru-
ment. When the points are placed parallel
to the axis the index stands at (zero),
showing that the surface is plane in that
direction.

* § 32. To find the Optical Centre of
a Lens is often a matter of practical im-
portance. It can be found in the same
Fig. 150. — Lens measurer, way as is the base-apex line of a prism
(Fig. 126). When both the crossed lines
seen through the lens are continuous with the portions outside the
lens, the optical centre is opposite the point of intersection of the
ines.

412

DISEASES OF THE EYE.

[chap. XV.

Fig. 151. — Prismatic effect of
decentration of lenses. A B and
C D represent the visual axes.

* § 33. Decentration of Lenses.— Normally, the distance between
the optical centres of the lenses in spectacles should be the same as
that between the optic axes of the eyes of the patient, otherwise

a prismatic effect would be pro-
duced. Sometimes, however, such
an effect is desirable, and then it
can be brought about by decentra-
tion of the lenses. This may be
done in one or other of two ways,
namely, by altering the distance
between the glasses by means of
the frames, or by decentring the
glass in its rim. The effect of the
first method is shown in Fig. 151,
from which figure, too, it is evident
that, in order to produce the same
effect, convex and concave lenses
must be displaced in opposite
directions.
The second method consists in cutting out the lens so that the
optical centre is displaced with reference to the geometrical centre.
By the geometrical centre we mean the central point of the piece of
glass constituting the lens. In round glasses it is of course equally
distant from all parts of the circumference, and in oval glasses it
is at the centre of the horizontal diameter of the glass. In lenses,
as commonly made, the optical centre coincides w^ith the geometrical
centre. Fig. 152 shows how a lens can be cut so that the optical centre
will be decentred. A B is the lens as origin-
ally ground, and B C D is the portion which
is cut out and fitted in the spectacle- rim.
If the whole of A B were used, the optical
centre, 0, would be the geometrical centre,
but in the portion C B U the point G, mid-
way between C D and B, would be the
geometrical centre, while the optical centre,

0, would be decentred. To obtain a prismatic effect of 1" a lens
of 1 D requires to be decentred If cm. The stronger the lens
the greater is the prismatic effect produced by a given amount
of decentration, so that a lens of 2 1) need onlv be decentred half

A<rw^B

Fig. 152. — Decentra-
tion of a lens by cutting
out a portion of it.

CHAr. XV.] ELEMENT ABY OPTICS. 413

the distance of a lens of 1 1), in order to produce the same pris-
matic effect. Tables have been constructed giving the prismatic
effect of lenses of different strength corresponding with the extent
of the decentration in millimetres.^

§ 34. Protective Glasses. — Glasses are chiefly used for the cor-
i-ection of optical errors (lenses), or for the relief of muscular in-
sufficiencies (prisms), but they are sometimes worn solely for the
protection of the eyes from injury by solid particles (stone-break-
ers, mineral-water operatives, motorists), by heat (smelters, glass
blowers), by excessive light (snow, electric light), or as a protection
from ordinary daylight in acute inflammation of the eyes accom-
panied by photophobia, and during the period immediately after
operations such as cataract extractions. For mechanical protection,
plate glass, celluloid, or wire gauze spectacles are employed. The
injurious effects of light, which are most probably due to the ultra-
violet rays, are best prevented by a special glass, such as amber-
coloured glass, or a specially made glass of a greenish-yellow tint
known as ' euphos ' glass. For ordinary clinical purposes smoked
or neutral tint glasses are preferable to blue.

^ See Maddox's work Ophthalmological Prisms.

CHAPTER XVI.

ABNORMAL REFRACTION AND ACCOMMODATION.

Ametropia. — It has been explained (p. 4) that, in Emmetropia
or Normal Refraction, the retina is at the principal focus of the
dioptric system. When the retina does not coincide with the
principal focus, parallel rays no longer meet on it, if the accommoda-
tion be at rest ; this condition is called Ametropia {a, priv. ; /xirpov,
standard ; wi//), or an error of refraction. There are three varieties
of Ametropia. 1. Myopia {/jlvuv, to close; oixp), or Short-sight;
in which the principal focus lies in front of the retina. 2. Hyper-
metropia {vmp, over ; fx^rpov, standard ; wi//), in which the principal
focus lies behind the retina. 3. Astigmatism (d, friv. ; o-ny/xa, a
point), in which the refraction of the eye in its different meridians
is different. ^

Myopia, or 8hort-8ight.

Definition and Optical Causes.— Myopia is an error of refraction
in which the retina lies behind the principal focus of the dioptric
system, and in which therefore parallel rays of light {a b, Fig. 153)
are brought to a focus, not on the retina, but in front of it (at /),
and form on it circles of diffusion (c d).

Compared with emmetropia, therefore, the refraction of the
myopic eye is increased. This may be due to shortening of the
focal length by an absolute increase in the refractive power of the
eye, brought about by increase of the curvature of the cornea, as
in conical cornea, or of the crystalline lens, as in spasm of accommo-
dation (Curvature M.), or by alteration in the refractive index of
the crystalline lens (Index M.), as in some cases of commencing
cataract, or by forward displacement of the lens, but in all of these
the myopia is of secondary importance.

414

CHAP, xvr.j

MYOPIA.

41.

The most conunon cause of myopia, is an elongation oi the
antero-posterior axis of the eyeball (Axial M.), and in this case the
increase of the refraction is therefore onlv relative.

Fig. 153.

Far Point (Punctum Remotum, R.) of the Myopic Eye.— The
myopic eye cannot see distant objects (at six metres or more) dis-
tinctly, because of the circles of diffusion (c d, Fig. 153), but if the
object be brought closer, its conjugate focus (§ 16, chap, xv.) will
lie farther back than /, Fig. 153, and when the object reaches a certain
point nearer to the eye, say R. Fig. 15-1, its conjugate focus will meet
the retina (at c) and it will be distinctly seen. This point — which
is the farthest point of distinct vision — is the Far Point or Punctum
Remotum (R.) The myopic eye is therefore adapted for seeing
near objects. Conversely rays emerging from c will unite at R,
which is the conjugate focus of the retina. It will be observed that,

Fig. 154, — Far point of^a^myopic eye.

in myopia, R is real and can actually be measured, that it lies in
front of the eye and is a positive quantity. As the position of R
in front of the eve determines the nature of the error of refraction,

410

DISEASES OF THE EYE.

[chap. XVI.

so the degree of error depends on the distance of R from the eye ;
the longer the eyeball the closer is R, and the greater is the error of
refraction. In other words, the error of refraction (;•) is the inverse

of the distance of the Far Point (R), r = — , and conversely of course

These are .general equations for all errors of refi'action.

Optical Correction of Myopia. — The optical correction of an error
of refraction is accomplished by placing in front of the eye a lens
which renders it emmetropic, or enables it to bring parallel rays

Fig.

-Correction of myopia.

[a, h, Fig. 155) to a focus on the retina, without any eSort of accom-
modation, and thus renders the vision of distant objects distinct.
Since rays diverging from the punctum remotum (R, Fig. 155) are
brought to a focus on the retina in the myopic eye, the correcting
lens, L, must evidently give to parallel rays such a degree of diver-
gence before they pass into the eye, as though they came from this
punctum remotum. This lens must therefore be a concave or
diverging lens, and its principal focus must be at R ; that is to say,
the focal length of the lens must be equal to the distance of the far
point from the eye, in this case 14 cm. The focus of the glass and
the punctum remotum of the eye are then identical ; and therefore,
parallel rays, after passing through the glass, will have a divergence,
as though they came from the punctum remotum, and will form
an exact image of the distant object on the retina. It is evident
that the glass will also make the rays emerging from the eye parallel.
The number of the glass, in this case,— 7 D (= -^{-), will indicate
the degree of the myopia — i.e. by how many dioptres the refracting
power of the eye is in excess of that of an emmetropic eye. The

ciiAr. xvj,]

MYOPIA.

417

longer the eyeball the shorter is the distance of the far point from
it ; and therefore the shorter must be the focal length of the cor-
recting lens, and the higher must be its number. The degree of
myopia therefore increases with the elongation of the eyeball.

In the explanation of the correction of myopia given above, the
correcting glass was assumed to be in contact with the cornea. In
practice, however, the glass is placed a short distance in front of the
cornea, and consequently, must be stronger than the theoretical cor-
rection. For example : if the punctum remotum (Fig. 156) be
situated at 20 cm. from the eye, then the number of the correcting
lens in contact with the eye, and the real measure of the myopia,
will be — 5 D, because the focal distance of this lens is 20 cm. {h^^-
= 5). But if, in the above case, the distance from cornea to glass
be 2 cm., the required lens in practice will be — 5*5 D (Y^/ = 5*5),

Fia. 15G. — Effect of the po-iition of the lens in the correction
of myopia.

Evidently, the farther the lens is from the eye the stronger must it
be ; and it is therefore advisable that correcting lenses should be
worn at the same distance from the eye as are the trial- lenses when
used to estimate the degree of ametropia. In the example just
given the difference between the theoretical and practical amount of
myopia is very slight, but it becomes greater the higher the myopia.
In a theoretical M. of 20 D, the lens required if placed at 2 cm. from
the eye would be — 33 D.

Diagnosis and Determination of the Degree of Myopia.— The
degree, or amount, of myopia may be determined either objectively
by the ophthalmoscope, or subjectively by means of the trial-lenses
and test-types.

Subjective Method. — Examining each eye separately, we find
the correcting glass by placing our patient as directed in the section
27

418 DISEASES OF THE EYE. [chap. xvi.

on AcutcMcss uf \'isioii (p, 14). Having first tested V. without a
glass, a weak concave trial-glass is then placed before the eye under
examination, and liigher numbers are gradually proceeded to, until
that glass is reached which gives the eye the best distinguishing
power for the types. In order to save time, the distance of the
far point can be found approximately with small print, and the degree
of M. deduced. A lens a little lower than this may be taken to
commence with. We often find that there are several glasses,
with each of which the patient can see equally well. The weakest
of these is the measure of his myopia. When a higher glass than this
is used the patient may still see well, but he does so only by an effort
of accommodation {i.e. the crystalline lens has to be made more
convex, in order to compensate for the excessive concavity of the
glass placed in front of the eye), and the glass employed represents
then, not merely the myopia present, but also this accommodative
effort. It is therefore a serious mistake to prescribe too strong con-
cave glasses for a myopic individual.

The Ophthalmoscopic Methods wnll be explained in detail
farther on (p. 447), and need only to be mentioned here.

Direct method at a distance. — The retinal vessels are visible and
appear to move in the opposite direction to the motion of the ob-
server's head.

Indirect method. — The optic disc appears to increase in size when
the object lens is drawn away from the patient's eye.

Direct method. — The fundus and vessels are indistinct, and the
lowest concave glass which makes them distinct is the measure of
the myopia.

Rhinoscopy . — With a plane mirror the shadow moves against
the direction in which the mirror is rotated, provided the observer
is farther from the patient's eye than the far point of the
latter.

The Amplitude of Accommodation in Myopia. — The myopic eye has
an excess of refractive power (r) as compared with the emmetropic eye ;
therefore, in calculating its amplitude of accommodation, tliis excess
must be subtracted from the positive refractive power (p), which would
be required to adapt the emmetropic eye to the same punctum proxi-
mum ; or, in other words, the myopic eye has need of less accommoda-
tive power than the emmetropic eye, because, even at rest, it is adapted
for a distance (R., its iDunctum remotum) for which the emmetropic eye
has to accommodate ; hence in myopia

a = p — r.

CHAP. XVI.]

MYOPIA.

410

For exainplo : a myopo of 4 D who cuii iiccoiiiinodalo up to 1 1 cm.
{p = W = -J ^) 1^'^^ '^'^ iunplitiido of accoininodation of 9 — 4 = 5 D.
Range of Accommodation in Myopia. — In myopia both R. and P., and

therefore the range of accommodation, are brought closer to the eye. The

-8/>

12 b cm

p'-ik-'"

8J)

H=^33 cm

9 cm

8 + 3=///>

20 cm.

Fig. 157. — Range of accommodation in emmetropia (E.), in myopia
(M.) and hypermetropia (H.) of 3 D each, the amplitude of accommoda-
tion in all cases being 8 D,

range is also shortened as can be seen from Fig. 157, which shows the range
of Ace. withan amplitudeof 8 D,in Em., andin M. and H. of 3 D, respectively.
In this case, R is known from the refraction (R = ^ ~ \ =33 cm.) ;
it remains therefore only to determine P. We saw above that in M. a =
p — r, therefore p = a + r =8 + 3 =11 D, and P. = - = iV = 9 cm.

The Angle y in Myopia. — In myopia, owing to the length of the eye-
ball, the cornea is cut closer to its centre by the visual line (M. Vi ., Fig. 1 58)
than in emmetropia ;j or, by displacement of the macular region the

Fig. 158. — Angle y in emmetropia (Em.), myopia (M.), and
hypermetropia (H.),

visual line and the optic axis (A O) may coincide ; or, the cornea may
even be cut to the outside of its centre by the visual line. In any of
these cases, but especially in the latter, the effect will be that of an apparent
convergent strabismus.

420 DISEASES OF THE EYE. [chap. xvi.

Etiology. —Myopia is rarely congenital. Infants are hyper-
metropic, but as they grow older the eye tends to become less hyper-
metropic, or emmetropic, or even in some cases myopic. Myopia
is almost wliolly a result of civilisation, and its development and
progressive increase are due to the use of the eyes for near work,
such as reading, sewing, drawing, etc., which causes elongation of
the antero-posterior axis of the eye. Only the portion of the eye-
ball posterior to the insertion of the orbital muscles takes part in
the change of shape. It is more common in cities than in the country,
and occurs especially in the higher schools, among the professional
classes, and those occupied with fine work. Opinions are divided
as to the way in which close work causes myopia. The effort of
accommodation is not the cause, but rather the pressure exercised
on the eyeball by the recti or superior oblique muscles during con-
vergence. Heredity also plays a part, the nature of which is not
clear ; but it would seem probable that some anatomical or con-
stitutional predisposition is transmitted from parent to offspring.
Finally, the higher degrees of myopia are very constantly complicated
with pathological changes at the posterior pole of the eye, called by
some posterior sclero-chorioiditis, and regarded by them as in-
flammatory, while others attribute them to the mechanical distension
of the coats of the eye, consequent on its elongation. How far this
disease is either the consequence, or the cause, of the elongation of
the globe has yet to be decided.

It should also be stated that anything which encourages ap-
proximation of objects to the eye such as defective print, bad light,
or indistinctness of vision, e.g. astigmatism, and nebula? of the cornea,
may act as indirect causes. The development of myopia may also
be assisted by anything which tends to produce congestion of the
head and eyes, such as stooping over books, as a result, for instance,
of badly constructed school desks. In rare instances, myopia has
been observed to develop or increase considerably after a severe
illness. That it is not always due to close work, is shown by the facts
that high degrees of myopia are veiy occasionally met with in young
children before they have begun to use their eyes much for near
objects ; and that the worst cases may sometimes be met with in
agricultural labourers, who have done little or no close work.

Myopia, as a rule, first shows itself from the eighth to the fifteenth
year, and is apt to increase, especially during the early years of

CHAP. XVI.] MYOPIA. 421

puberty. After this the majority of cases remain stationary, but
others continue to increase during the whole lifetime, either periodi-
cally or continuously, and may reach 30 D or more.

Simple, or Non-Progressive Myopia.— In this variety, the M.
ceases to increase when the body has reached its full development,
and does not, as a rule, go beyond three or four dioptres. The eye
is perfectly sound and presents no disease of the fundus, except
occasionally a slight crescent at the outer side of the optic disc
(Plate IX. Fig. 1). This form of myopia is sometimes regarded as a
harmless adaptation of the eye to the requirement of civilisation,
and as being different in its etiology from the progressive form,
which is a true disease. Unfortunately it is not possible to dis-
tinguish with certainty one form from the other in the earliest
stage. But if a patient of sixteen years of age or more have a
low degree of M., say only of 2 D or 3 D, and especially if there
be no crescent, one may feel fairly confident that the M. will become
stationary when the patient is fully grown. The points which
guide one in the prognosis are the age of the patient compared with
the amount of the M., and the appearance of the fundus.

Spasmodic Myopia — that is to say, M. due to spasm of accom-
modation — is a condition which is not uncommon, and one which
is frequently seen, during the transition of H. or Em. into M. The
M. disappears under atropine, only to return when the use of the
latter is discontinued.

Symptoms of Myopia.— The symptoms of M., apart from the
complications which occur in the high degrees, and which will be
considered later on, are dependent on the optical error of the eye,
and are very few. Distant vision is impaired according to the
degree of M. present, but many short-sighted people half close their
eyes in order to diminish the size of the diffusion circles on the retina,
and they are thus enabled to see a little better. It is this habit
which has given rise to the term myopia (p. 414). The smallest print
can be distinguished with great facility, at or within the near point ;
and as the retinal images are larger than in emmetropia and con-
sequently require less illumination for their perception, short-sighted
persons are much given to reading in bad light. If the patient
reads at his far point no accommodation is necessary, and for a
nearer point the accommodation being less than in emmetropia,
one of the stimuli to convergence is deficient, and in some cases this

422

DISEASES OF THE EYE.

[chap. XVI.

leads to latent, or even to absolute divergence (see Insufficiency of
Convergence, chap. xvii.).

The particles which normally float in the vitreous humour are
rendered more noticeable by the larger shadows which they cast
on the retina ; and this is one of the reasons why myopic people
are so frequently troubled by black spots (muscat volitantes) before
their eyes. That short sight improves with age, or is the strongest
kind of eye, is a fallacy which owes its origin to the absence or de-
layed onset of presbyopia in myopic people ; and also to the fact
that, in low degrees of myopia, the vision may improve a little at
a distance owing to the small size of the
pupils in old people, or to the slight di-
minution in the refractive power of the
lens which occurs at about sixty years of
age (cf. Presbyopia).

Progressive Myopia frequently becomes
complicated with Organic Disease, and to
the more serious
Myopia may be
are the forms
with :

1. Posterior Staphyloma, or Myopic Cres-
cent. — This condition is recognised by the
ophthalmoscope as a more or less extensive
white crescent at the outer circle of the
optic papilla.
Fig. 159 explains the manner in which it arises. The bulging
of the eyeball, at X, takes place at the posterior pole, in the direction
of the axis A X. The chorioid c becomes drawn towards the tem-
poral side, and the optic nerve appears to be displaced in the opposite
direction. The chorioid is, consequently, drawn over the edge of
the scleral opening at the nasal side at n, while it becomes detached
and drawn away from it at the outer side at t, the portion of sclerotic
thus exposed appearing as a white crescent at the temporal edge of
the disc (Plate IX. Fig. 1). As the bulging increases, with in-
crease of the myopia, it extends to the nasal side of the nerve as
well, the chorioid also becoming atrophied ; and the posterior
staphyloma ^ is then seen with the ophthalmoscope completely sur-
' Staphyloma \n ophthalmology m.eans a bulging of the coats of the

cases the term Pernicious

applied. The following

of organic disease met

Fig. 159. — Explains
formation of myopic
crescent.

.a s-8

.oi'5

PLATE IX.

{To face page 422.)

Fia. 1. — This represents a small myopic crescent in a case of myopia of
3*5 D. The orescent is white, and is situated on the temporal side
of the disc.

Fig. 2. — Posterior staphyloma in myopia of high degree. The staphy-
loma surrounds the disc, but the larger portion of it is on the tem-
poral side. The disc appears as a vertical oval. The chorioidal
vessels have become visible in the neighbourhood of the disc, owing
to atrophy of the pigment-epithelium. The macular region (to the
left) shows evidences of disease, in the form of atrophic spots and
lines, irregular pigmentation, and haemorrhages.

Plate IX.

l..\v.

Fig. 1. Myopic Crescent.

l..\V,

Fig. 2. Large Posterior Staphyloma.

CHAP. XVI.] MYOPIA. 423

rounding the disc, but always larger at the temporal side. The
stretching of the retina may, in extreme cases, derange its functions
and increase the size of the blind spot. The disc itself appears oval,
owing to the oblique position which the nerve head acquires (Plate
IX. Fig. 2). The size of the staphyloma generally corresponds with
the degree of M. although exceptions to this occur. Every case
in which a small crescent is present is not to be regarded as serious ;
for much here depends on the age of the patient and the degree of
the myopia. The younger the patient and the higher the myopia,
the more serious is the outlook.

2. Chorioidal Degeneration in the Neighbourhood of the Macula
Lutea (Plate IX. Fig. 2). — This should always be carefully looked for,
as the region of the yellow spot is very liable to disease in the worst
cases of progressive myopia. The disease seems to begin in the
chorioid, giving the appearance of small cracks or fissures, which,
at a later period, develop into a patch of chorioidal atrophy. The
retina at the yellow spot becomes gradually disorganised, and very
serious disturbance of vision, associated in the early stages with
metamorphopsia, is the result, the patient being disabled from
reading, although, as the periphery of the fundus is usually sound,
he can find his way about freely. Treatment can do little here.
Abstention from near work, and the wearing of dark glasses, are to
be recommended.

3. Chorioidal Exudation in the Neighbourhood of the Macula
Lutea. — A small grey spot of exudation may appear in the chorioid
at this place, accompanied by loss of sight for reading. These cases
are often amenable to active mercurial treatment, when sight may
be restored. Should the case be neglected or run a bad course,
vision will be permanently damaged from secondary chorioidal de-
generation.

4. The Black Spot in Myopia. — This disease also attacks the
chorioid in the region of the yellow spot, and causes a loss of central
vision, as in the two previous forms of disease. The appearance
shown by the ophthalmoscope is that of a black spot, usually quite

eye (see anterior staphyloma, pp. 146 and 171). In myopia the area of
atrophy, called above posterior staphyloma, is smaller than the real area
of distension of the back of the eye. This is apparent in Fig. 159. The
edge of this true posterior staphyloma can sometiines be seen with the
ophthalmoscope, the retinal vessels suddenly dipping in over it.

424 DISEASES OF THE EYE. [chap. xvi.

circular and with a defined margin. In the early stages its size is
much smaller than that of the papilla, but later it often attains a
dimension of two papilla diameters, or more. The spot is rarely
of an equal intensity of blackness all over, but towards its centre a
faint reddish liue often shines through in places. At a later stage
the black spot becomes surrounded by a narrow whitish l)order,
while towards its centre it becomes less black, and finally greyish
or even white, its margin remaining black. Although small haemor-
rhages, which often occur in the neighbourhood of the black spot,
gave rise to the opinion that the black spot was itself the result of
hsemorrhage, yet this seems not to be so, as the investigations of
E. Lehmus have shown. The disease consists in a proliferation of
the pigment epithelium, combined with a gelatinous exudation,
which in the case examined had attained a thickness, at the centre
of the black spot, of two-thirds that of the chorioid. The chorioid
was but very slightly altered, and the glass membrane was quite
normal. At the margin of the proliferating region the pigment
epithelium was found to be paler or even quite free from pigment.
The black spot very gradually, in the course of years, attains its
ultimate dimensions, and then very slowly retrogresses, until finally
its place is taken by a greyish or bluish-white scar. Treatment is
of no avail, and central vision does not become restored.

5. General Chorioidal Atrophy. — In advanced cases of pernicious
myopia, large patches of chorioidal atrophy, other than the crescent,
are often present, chiefly in the region of the posterior pole, but often
also towards the periphery of the fundus. The vitreous humour in
these cases is more fluid than normal, and usually contains many
opacities. Treatment by means of sub-conjunctival saline injections
is occasionally of use in clearing up the vitreous humour, and thus
effects some improvement of vision. The eyes should not be used
for near work, and dark glasses should be worn.

6. Hcemorrhage in the Retina at the Yelloiv Spot may occur, and
when the hjicmorrhage becomes absorbed the macula lutea may not
recover its function, owing to the delicate retinal tissue having been
seriously damaged. Yet we often meet with cases of this kind which
do regain their former vision. Rest of the eyes and dark glasses
should be prescribed.

7. Detachment of the Retina. — This is a frequent and most serious
complication of progressive myopia, and sometimes leads to second-

CHAP. XVI.] MYOPIA. 425

ary cataract and even to shrinking of the eyeball (Phthisis Bulbi).
It has been considered in the chapter on Diseases of the Retina.

In high degrees of M. the eyes are unduly prominent, and the
sclerotic appears flatter at the sides ; the pupils are usually large
and the anterior chamber deep, owing to the slight development of
the ciliary muscle in consequence of the non-use of accommodation.

Functional Anomalies attending Progressive Myopia. —

{a) Insufjicicncij of Convergence is almost always associated with
progressive myopia, and is the re.iult of two causes, namely the
diminished impulse to convergence produced by the absence of
accommodation, and the mechanical difficulty introduced by the
elongation of the eyes. The insufficiency of convergence may be
only latent, or it may lead passively to absolute divergent strabismus
(chap. xvii.).

(6) Cramp of Accommodation is often present and causes an
apparent increase in the myopia (p. 421).

The Management of Myopia.— In view of the tendency to in-
crease, to which, especially during adolescence, nearly every case of
short-sight is liable, and of the fact that in a given case we cannot
tell to what extent this increase may go, and, finally, as the high
degrees almost invariably lead to disease of the eye, the manage-
ment of myopia, including the prescribing of glasses for it, is one
of the most important matters with which we have to deal.

The Prescribing of Glasses in Myopia. — It is not necessary to
prescribe glasses for very slight degrees of myopia (up to TO D or
rS D) ; yet, should the patient desire to wear correcting glasses
for distant objects, there can be no objection to it. But for cases of
myopia of 2*0 D or more, unless presbyopia be also present, it be-
comes very desirable to prescribe glasses which fully correct the
myopia, to be worn constantly — i.e. for both distant and near
objects ; and, should the myopia increase, to accordingly increase
from time to time the strength of the glasses.

We now know% on the one hand, that the action of the muscle
of accommodation does not produce a pull on the chorioid farther
back than the equator of the eyeball, while on the other hand it is
at the posterior pole that the diseased processes in myopia com-
mence. Nor does the ciliary muscle by raising the tension of the
eye, nor in any other way, cause an elongation of the eyeball. Hence,
there is no reason to spare the healthy myopic eye any ordinary

426 DISEASES OF THE EYE. [chap. xvr.

effort of accommodation. Indeed, it is reasonable to think that if
normal efforts be required of the ciliary muscle, its more healthy
tone will improve the general healthy nutrition of the uveal tract, and
consequently will tend rather to avert morbid changes in it.

On the other hand, the diminution of the angle of convergence
at near work is a truly important matter, for the reason above
stated ; but it is more effectually provided for by full than by partial
correction.

Practical experience is here even more valuable than theory,
and it shows that in a large majority of those patients whose short-,
sight has been fully corrected in youth, and who have worn their
spectacles constantly for a number of years, the myopia in many
instances has not increased at all, while in a large proportion the
increase will have been moderate, and in but a small proportion
marked pernicious progress will be noted. In short, the tendency
to increase of the myopia, and to organic disease, is less than in those
myopes who have either worn no glasses, or but partially correcting
glasses.

Well-fitting, properly centred spectacles are much to be preferred
to folders, which are difficult to keep correctly centred before
the eyes. Any astigmatism present should always be corrected.
Patients whose eyes are healthy, and who wear constant full correc-
tion, may be permitted, and even encouraged, to use their eyes
freely for near work, always keeping the work as far from the eyes
as possible, to diminish the angle of convergence. With this latter
object in view, too, well-printed books, ample light, and suitable
reading- and writing-desks should be provided in all educational
establishments, and for home studies.

But in prescribing the full correction for constant wear to young
short-sighted persons, we meet with some difficulties. The first of
these is due to the range of accommodation, which is imperfect in
the myopic eye, and consequently the patients may complain of
painful accommodative sensations when first using their fully
correcting lenses for near work, and sometimes they decline to persist
in the attempt. These complaints are more likely to be made by
patients of about twenty years of age or more, whose habit of use of
their eyes (relative amplitude of accommodation, and degree of
convergence) has become more or less confirmed, and in whom the
power of accommodation has naturally diminished to an appreciable

CHAP. XVI.] MYOPIA. 427

degree. Patients should be encouraged, in spite of discomfort, to
continue for some time longer to read, etc., with the full correction,
when, very often, the relative amplitude of accommodation will
gradually improve, and the discomfort will cease. Or, a lower
number than the full correction may be ordered, and the strength
gradually increased, until in the course of some weeks or more,
the full correction can be worn for near work with ease.

Myopic persons of middle age and over, who have never worn
the full correction, will rarely tolerate it.

Operative Cure of Myopia. — This consists in diminishing the refrac-
tion of the eye by the removal of the crystalHne lens. Some surgeons
simply extract the clear lens, while the majority now, including the authors,
perform discission, followed, in a few days, by the evacuation of the swollen
and cataractous lens, and in some cases by a subsequent capsulotomy.
A larger number of operations than this is apt to be injurious ; moreover,
the swollen lens should be removed before the tension of the eye becomes
increased. For both of these reasons, therefore, simple discission without
extraction is inferior to the other method. There are grounds for sus-
pecting that, in these highly myopic eyes, the tendency to retinal detach-
ment is increased by the operation, although this has not been shown by
statistics.

The operative cure of myopia is not to be recommended except for
cases of 1 5 D and more ; nor should it be performed where there is such
serious disease of the fundus or vitreous humour as would render any im-
proved use of the eye on conclusion of the treatment unlikely. Active
chorioidal disease is regarded as a contra-indication, but small retinal
haemorrhages, even if they be near the macula lutea, need not be so re-
garded. The best time of life for the cure is in childhood or in early youth,
but it can be successfully undertaken at a much later period. In the
myopic eye the nucleus of the lens undergoes sclerosis to a less extent
than in hypermetropia or in emmetropia, and hence in it discission is less
apt to be followed by high tension or other complication, even when
performed in middle age.

The advantages gained by the patients from the operative cure of
their myopia are very great. Not merely do they become sometimes
emmetropic, but the acuteness of vision is usually increased in a remarkable
degree, being occasionally even double or treble that which previously
existed with the correcting glasses. This improvement is chiefly due
to the increased size of the retinal images. The reduction in the refraction
is much greater in these cases, than after removal of the lens for cataract
in an emmetropic eye. In the latter case a convex lens of 10 D is required
to correct the eye for distance, whereas a myope of 20 D most commonly
requires no correction for distance after the removal of his lens. The
explanation of this is simple. When the lens is removed, the only re-
fracting surface then is the cornea, the focal length of which is approxi-
mately 31 mm. ; a myopic eye therefore which is 31 mm. long would, when

428 DISEASES OF THE EYE. [chap. xvi.

deprived of its lens, bring parallel rays to a focus on the retina «,nd
would require no correction for distance. Since the average focal length
of the emmetropic eye is 24 mm. this myopic eye would be 31 — 24 =
7 mm. longer than the emmetropic eye. Now it can be easily shown that,
in the complete eye containing the lens, every millimetre of increase in
length corresponds with an increase of 3 D of refraction, consequently
in this case before operation, when the lens was present, the refraction
would have been increased by 3 x 7 = 21 D, a result which agrees in
most cases with practice.

In the absence of the lens an increase of 1 mm. in length of the eyeball
only augments the refraction of about 1*5 D, that is to say, only half the
amount which the same increase of length produces in the complete eye. A
simple rule, therefore, for finding approximately what the refraction will
be, after removal of the lens, in a given case of myopia, is to take half the
nianber of dioptres of the myopia and subtract it from 10. If the result
be positive a plus lens will be required after operation, and if negative
a concave lens. For example, a myope of 10 D will require a + 5 D,
for correction after operation, 10 — V" = 5, and a myope of 30 D will
remain with 5 D of myopia, 10 — "V^ = — 5. In practice cases some-
times occur which do not fall in with this theory, and for this there are
reasons which cannot be fully entered into here, but amongst them is
the difficulty of an exact estimation of the refraction in high M. and the
possibility of the M. being not merely axial, but also caused by shortening
of the focal length of the dioptric system.

The mere possibility that detachment of the retina may be caused, or
hastened, by the operation is a sufficient reason for limiting the operation
to one eye. It is wiser not to operate on the second eye, even though a
successful result may have been obtained in the first, and though the
patient, as often happens, may desire the operation. The eye which has
been operated upon will serve for distant vision and its fellow for near work,
and thus, where the eye after operation becomes emmetropic, the patient
is rendered independent of glasses. It has not been proved that re-
moval of the lens arrests the progress of myopia. Many ophthalmologists
do not now regard this operation with favour, but we employ it for
selected cases, in one eye only.

Hypermetropia.

Definition, and Optical Causes. — In Hypermetropia the retina
lies in front of the principal focus of the dioptric system, and there-
fore parallel rays of light {a, b, Fig. 160), falling into the hyper-
metropic eye (E), do not meet on the retina, but converge towards a
point (c) situated behind it. As compared with emmetropia the
refraction of a hypermetropic eye is diminished. It may be caused
by displacement of the retina forwards, from shortening of the eye-
ball (Axial H.), or by elon.iTatiou of tlie focal length of the dioptric

CHAP. XVI. J

H YPERMETROPIA .

429

system tlirougli flattening of tlie cornea (Curvature H.), absence of
the lens (dislocation, cataract extraction), or diminution of the
refractive index of the lens in old age (senile hypermetropia).

Fig. 160.

Far Point (R.) of the Hypermetropic Eye.— Since paralleljays
do not unite on the retina, but produce there a circle of diffusion
{d, e, Fig. 160), the hypermetropic eye cannot see distant objects dis-
tinctly, and if an object be brought closer, its focus will lie still farther
behind the retina (§ 17, chap. xv.). There is therefore no position
between infinity and the cornea, from which rays of light would
unite on the retina of the hypermetropic eye ; in other words, there
is no real far point. What kind of rays then do come to a focus on
the retina of a hypermetropic eye ? The answer will be found by
considering the course of the rays emerging from the eye. Since
the refraction is deficient or, what is the same thing, since the
retina lies in front of the principal focus F. Fig. 161 (§ 18, chap, xv.),
rays coming from any point (c), will not even be rendered parallel,

Fig. IGl,

but will pass out as divergent rays (/, g) , and they can therefore never
meet to form a real conjugate focus, or far point. But they will
diverge as if they came from a point R, situated behind the eye,
which point is the virtual conjugate focus of the point c on the retina.

430 DISEASES OF THE EYE. [fTiAP. xvi.

R is the virtual far point. It is situated behind the eye, is negative,
and cannot be measured directly as in myopia. Conversely, if the
rays /, j/, enter the eye with a convergence towards R, they will unite
on the retina. The hypermetropic eye therefore is only adapted,
when at rest, for convergent rays. The shorter the eyeball, the
farther the retina is from F, and the greater the divergence of the
emerging rays, and consequently the shorter will be the distance of
the far point, and the higher the error of refraction. In hyper-

metropia, as in myopia, /• = — , but here R is negative, and therefore

r, the error of refraction, is also a negative quantity.

Fig. 162. — Correction of hypernietropia. R = far point, r = error
of refraction.

Optical Correction of Hypernietropia. — In order to correct
hypermetropia — that is, to render the eye emmetropic, so that
parallel rays may be brought to a focus on the retina (c, Fig. 162) —
a lens must be placed in front of the eye, which will give to the
parallel rays {a, h) before they enter it a convergence towards its
far point, R. This lens must therefore be a converging or + lens,
and its focal length must be equal to the distance of R from the
eye (in this case 25 cm.). The negative error, or deficiency in the
refraction, is corrected by a -j- lens (L), which increases the refrac-
tion, and thereby shortens the focal length of the eye so as to bring
the focus on to the retina. The shorter the antero-posterior axis
of the eyeball, the closer is R, and the shorter therefore must be the
focal length of the correcting lens. That is to say, the correct-
ing lens must be stronger, and the hypermetropia consequently
greater, when the eye is shorter.

CHAr. xvT.l HYPERMETROPIA. 431

It is evident that the farther the lens (J.) is from the cornea the
greater is its distance from R, and therefore the weaker the lens
which is required. This is the reverse of what takes place in myopia

(p. ^17).

Hypermetropia can also be corrected by an effort of accommo-
dation, in which the increased convexity of the crystalline lens
within the eye takes the place of the correcting glass. In the case
represented by Fig. 162, an accommodation equivalent to 4 D would
be required.

Determination of the Degree of H. Subjective Method by
TRIAL-LENSES AND TEST-TYPES. — Since accommodation tends to
correct hypermetropia, care must be taken in drawing conclusions
from this method of examination. If the acuteness of vision be
improved by a convex lens, H. is present, but it may be found that,
with a lens of some dioptres less, the eye will see equally well ; this
means that an effort of accommodation supplements the weaker
lens placed before the eye. As higher lenses are proceeded to, the
effort of accommodation is relaxed, until, finally, the strongest lens
wdth which vision is still at its best is reached, when, it may for the
present be assumed, no further efiort of accommodation is made,
and this lens then represents the whole error of refraction.

In low degrees of hypermetropia, accommodation frequently
corrects the whole of the H. When such an eye is found to have
full vision without a glass, a beginner may fall into the error of
regarding it as emmetropic ; but if he take the precaution of placing
a low convex lens in front of it, and then finds that the acuteness of
vision remains as good as without the glass (because the effort of
accommodation is now relaxed), he will avoid this mistake, unless
there should be tonic cramp of accommodation, which might partially,
or even completely, mask the hypermetropia.

If a glass a single number higher than the exact measure of the
defect be placed before the eye, vision again becomes indistinct,
because the rays are then brought to a focus in front of the retina,
and a circle of diffusion is formed on the latter. The eye, in fact,
is put by such a glass in a condition of myopia. Therefore the
strongest convex glass with which a hyfermetrofic eye can see distant
objects (the test-types) jnost distinctly is the glass which corrects its
hypermetropia, and is the measure of the latter. Very commonly it
is only the manifest hypermetropia {vide infra) which is ascertained

432 DISEASES OF THE EYE. [oiiap. xvi.

by this method, unless the accommodation has been previously
paralysed by atropine.

Objective, or Ophthalmoscopic Methods. Direct Method at a
Distance. — The retinal vessels are visible, and appear to move in
the same direction as the motion of the observer's head.

Indirect Method. — The optic disc appears to diminish in size as
the lens is withdrawn from the patient's eye.

Direct Method. — The strongest convex glass with which the
fundus and vessels can be seen distinctly is the measure of the H.

Retinoscopij. — With a flane mirror the shadow moves in the same
direction as* that in which the mirror is rotated, that is to say, with
the mirror.

Amplitude of Accommodation in Hypsrmstropia. — When at rest the
refraction of the hypermetropic eye is deficient, consequently r must be
negative ( — r), and the amplitude of accommodation must include the
correction required to adapt the eye to infuiity ; therefore the formula
for the amplitude of accoinmodation (p. 6) becomes

a = p — { — r) = f -\- r.

For example : if the punctum proximum of a hypermetropic eye of
5 D be at 30 cm., what is the ainplitude of accommodation ? 5 D ( = r)
is necessary in order to make the eye emmetropic, and to accommodate
the emmetropic eye to 30 cm. 3*25 D ('yV = 3'25) is required. Hence
a = 3-25 + 5 = 8-25 D.

Range of Accommodation in H. — In hypermetropia a part of the
patient's amplitude of accommodation is used to correct the error of
refraction, the remainder only being available for the purpose of adapting
the eye for a near point. It follows, therefore, that, with the same ampli-
tude of accommodation as an emmstrope, the near point will be farther
away from the eye in hypermetropia. This is shown in Fig. 157, which
represents the ranges of accommodation in emmetropia (E.), myopia of
3 D (M.), and hypermetropia of 3 D (H.), the amplitude being 8 D.

Th3 Angle y in Hypermetropia. — In hypermetropia, as in emmetropia,
the cornea is cut to the inside of its axis by the visvial line ; but in hyper-
metropia the angle which the visual line forms with the optic axis is greater,
owing to the shortness of the eyeball, the effect of which is to incease
the angular distance between the macula lutea and the optic axis {O A,
Fig. 158). Consequently, in extreme cases, when the two visual lines of
a hypermeti-opic individual are directed to an object, the axes of the cornese
may seem to diverge, and thus the appearance of a divergent strabismus
will be given (see apparent strabismus, chap, xvii.).

Varieties of H. in Relation to Accommodation.— Hypermetropes

endeavour to correct as much of the error of refraction as possible

CHAP. XVI.] HYPERMETROPIA. 433

by accommodating, and the ciliary muscle is thus kept persistently
contracted even though the visual axes remain parallel.

In young persons this spasm is not, or may be only partially,
relaxed when the correcting convex glass is held before the eye,
and consequently the whole or part of the hypermetropia may be
masked by the cramp. That part of the hypermetropia which is
thus masked is called latent (HI.), while the part which is revealed
by the convex glass with which the test-types are read is called
manifest (Hm.). The entire hypermetropia is made up of the latent
and manifest H. (H. = Hm. + HI.).

If the Hm. cannot be corrected by accommodation it is called
absolute H., if it can be so corrected it is known as facultative.
For example, a patient without glasses has V = yg, and with +
r5 D, V = f ; with 2'5 D also, V = J, but when accommodation
is paralysed the H. is found to be 4 D. In this case the total
H. is 4 D, the Hm. is 2*5 D, of which Vb D is absolute and 1 D
facultative, while there is TS D latent H. The relation between
the Hm. and H. varies with the age and general health of the
individual.

When the spasm persists so that the accommodation cannot be
relaxed, the vision is then made worse, even by a weak convex
glass, thus simulating emmetropia. We then say that the whole
hypermetropia is latent. Or, in extreme cases of accommodative
spasm, parallel rays may be united in front of the retina, and the
eye made apparently myopic, distant vision being actually capable
of improvement by concave glasses. Some of these patients cannot
maintain a sustained view of an object at any distance without
suffering pain in and about the eyes. Examination with the ophthal-
moscope, or paralysis of accommodation with atropine, will enable
the surgeon to avoid mistakes.

In order to relieve this cramp, or to ascertain the real state of
the refraction, especially in children, atropine must be freely in-
stilled ; and it will often be necessary to keep the accommodation
paralysed for some days, and to commence the use of the correcting
spectacles before the effect of the atropine begins to wear off. In
this way a recurrence of the spasm may be often prevented.

As life advances, and the power of accommodation diminishes,
the manifest part of the hypermetropia increases, while the latent
part decreases, until finally Hm. = H.
28

434 DISEASES OF THE EYE. [chap. xvi.

Etiology.— Typical hyperinetropia is practically always axial—
i.e. due to a short eyeball. Children are hypermetropic at birth,
but with growth of the body the eye develops and becomes less
hypermetropic, or emmetropic, or even myopic. So that the hyper-
metropic eye may be regarded as an undeveloped organ, and indeed
the highest degrees of H. are met with in very small (microphthalmic)
eyes, which are often the subjects of congenital malformations.
The eyes of animals and of uncivilised nations are hypermetropic.
When the period of growth ceases, any H. which may then exist
remains stationary. There is never any progress, as in myopia ;
and very high degrees are rarely seen, even 12 D being unusual.
Hypermetropic eyes are moreover healthy, and free from the com-
plications which follow mechanically from the change in shape of
the myopic eye.

Symptoms and Signs of H.— These depend chiefly on the relation
of the H. to the amplitude of accommodation, and will be under-
stood from what has been already stated. Both distant and near
vision may be perfect, or near vision alone may be defective, or both
may be imperfect. In high degrees of H. patients sometimes hold
the book close to the eyes in order to obtain larger retinal images,
but they cannot read the smallest type with the ease and fluency
of the myope. Even with correction, vision is often defective in
these cases, more especially if astigmatism be present in addition
to the H. Slight redness and veiling of the edges of the optic disc
with tortuosity of the retinal vessels is sometimes seen, and must
not be mistaken for optic neuritis. The normal appearance of the
retina known as " shot silk " is better marked and of more frequent
occurrence in young hypermetropes than in other conditions of
refraction. Hypermetropic eyes show increased curvature of the
sclerotic at the outer side, when the eye is rotated inwards, the
pupils are smaller than in Em., and the anterior chamber is shallow.
Other consequences are accommodative asthenopia, and convergent
strabismus.

Accommodative Asthenopia (u, priv. ; aOivo^, strength ; wi//).—
This is the name given to the group of symptoms which occur when
the patient is unable to sustain the accommodative effort required
for near vision. A hypermetrope, having used up part of his
accommodation for distance, has for near objects actually less at
his disposition than an emmetrope. Hence, hypermetropic people

CHAr. XVI.] HYPERMETROPIA. 435

often complain of inability to sustain aLconiniodative eHoits for
near objects for any length of time. After reading, sewing, etc.,
for a short time, sensations of pressure in the eyes, of weight above
and around them, and more or less pains in the brow and temples,
come on, and the words or stitches become indistinct, and cannot
be distinguished, and the efforts to see are attended with lacrimation,
frowning, and even with facial contortions. The work must then
be interrupted, and after a few minutes' rest it can be resumed, but
must soon 'again be given up. After a Sunday's rest the patient
is often able to get on better than on the previous Saturday. These
symptoms depend simply upon inability of the ciliary muscle to
answer to the excessive demands made upon it.

Accommodative asthenopia often appears suddenly during or
after illness, the explanation being that, although hypermetropia had
always existed, yet in health the ciliary muscle was equal to the
great efforts required of it, but in sickness it shared the debility
of the system in general.

Internal, or Convergent Concomitant Strabismus.— This con-
dition has a certain relation to hypermetropia. It will be treated
of in the chapter on the Motions of the Eyeballs and their Derange-
ments (chap. xvii.).

The Prescribing of Spectacles in Hypermetropia.— If a person
be found to be hypermetropic, but his acuteness of vision without
glasses be good, or as good as he desires, and he complain of no
asthenopic symptoms, glasses need not, indeed should not, be pre-
scribed for him. No harm will come to his eye from his going
without glasses.

If the patient complain of imperfect distant vision due to hyper-
metropia, then those lenses w^hich correct the Hm. may be pre-
scribed for distant vision, to be worn either constantly or occasion-
ally, as he may desire. Such a patient is almost certain to complain
also of accommodative asthenopia ; while many patients will be
met with who complain of the latter, yet express themselves as per-
fectly satisfied with their distant vision. For relief of their asthen-
opia it is usually enough to prescribe spectacles for near work which
will correct the Hm., along with 1 D or 2 D of the HI, if the latter
exist.

If there be excessive cramp of accommodation, or strabismus,
glasses to correct the whole hypermetropia should be worn while

436 DISEASES OF THE EYE. [chap. xvi.

the eye is under atropine ; and afterwards as much of tlie 111. as
possible, along with the Hm., should be corrected by glasses to be
worn constantly.

Astigmatism.

In this form of ametropia the refracting surfaces are not spheri-
cal, and consequently, rays of light from a luminous point are not
brought to one focus. The defect usually lies in the cornea, and the
astigmatism may be regular or irregular.

In Hegular Astigmatis7n, which is congenital, the directions of
the greatest and least curvatures of the cornea are always at right
angles to each other, and usually fall precisely in the vertical and
horizontal meridians, the meridian of greatest curvature being most

Fig. 103.

frequently the vertical. The surface of the cornea then resembles
the back of the bowl of a spoon, which is more convex from side to
side than from heel to point. Astigmatism is said to be '' with the
rule " when the meridian of greatest curvature is vertical, and
" against the rule " when this meridian is horizontal. Hence a
pencil of rays passing into the eye, instead of meeting at a common
focus, is refracted in such a way that the rays passing through the
vertical meridian of the cornea are brought to a focus much earlier
than those which fall through its horizontal meridian.

Fig. 163 shows the different forms which the image of a point
assumes after the passage of the rays through an astigmatic surface.

At A neither vertical {v v') nor horizontal {h h') rays have yet
been united at their foci, but the vertical rays are the nearest to
their focus ; and therefore here the appearance of the image on an
intercepting screen, is an oval with its long axis horizontal, as shown
by the dotted line. At B the vertical rays have met at their focus,
but the horizontal rays not as yet at theirs, the effect being a hori-

CHAP. XVT.]

ASTIGMATISM.

437

zontal straight line. At C the vertical rays are diverging again
from their focus, and the horizontal rays have not come to theirs.
At D the same conditions exist, only a little farther on, where one
set of rays is diverging, the other still converging, but each at the
same angle ; hence the figure is a circle. At F the horizontal rays
have met, and the result is a vertical straight line. At G both sets
of rays are divergent, and the figure is an oval with the long axis
perpendicular. An astigmatic eye has, therefore, two foci, each
being represented l)y a line, and not by a point. The interval be-
tween the foci of the two principal meridians (B and F, Fig. 163) is
called the Focal Interval and is a measure of the astigmatism.

There are various kinds of regular astigmatism, according to
the position of the two principal foci with reference to the retina,
as follows : —

1. Compound Hypermetropic Astigmatism. — Both foci behind the

Fig. 164.

Fia. 165.

retina, that of the horizontal rays (H, Fig. 164) farther back than
that (V) of the vertical rays. Hypermetropia in both meridians,
but greater in the horizontal.

2. Simple Hypermetropic Astigmatism. — The focus of the vertical
rays (V, Fig. 165) on the retina (emmetropia in that meridian) ;
that of the horizontal rays (H) behind the retina (hypermetropia in
that meridian).

3. Mixed Astigmatism. — The horizon-
tal focus (H, Fig. 166) behind the retina
(hypermetropia in that meridian), and
the vertical focus (V) in front of the
retina (myopia in that meridian).

4. Simple Myopic Astigmatism,. — The
horizontal focus (H, Fig. 167) on the retina (emmetropia in that
meridian), the vertical focus (V) in front of the retina (myopia).

438

DISEASES OF THE EYE.

[chap. XVI.

5. Compound Myopic Astigmatism. — Both foci in front of the
retina, but the vertical focus farther forward (V, Fig. 168).

Fig. IC)-;

Fig. 168.

Symptoms of Regular Astigmatism.— We may conclude that
an individual is astigmatic if he see horizontal (or vertical) lines,
such as the horizontal portions of Roman capital letters, or the
horizontal lines in music, or the horizontal rays in Snellen's Sunrise
figure (see end of this book) distinctly, while the vertical (or horizon-
tal) lines seem indistinct. Patients seldom, however, complain of
this peculiarity in their vision.

To explain the perception of lines by an astigmatic eye, let us
suppose an eye to be emmetropic in the vertical meridian, and
ametropic in the horizontal meridian ; we must first consider how
a point will be seen by such an eye. The rays of light emitted from
the point and passing through the horizontal meridian will not be
brought to a focus on the retina, but will produce a blurring of the
retinal image of the point at each side ; while the vertical rays will
unite on the retina, and consequently the point will appear distinctly
defined above and below.

Now, a line may be regarded as a number of points, and it is
only necessary therefore to arrange a number of points, blurred at

^ 6

Fig. 169.

Fig. 170.

the sides, in horizontal and vertical lines — as at a and h in Fig. 169.
It is evident at once, from mere inspection, that the horizontal Kne
will appear distinct, because the rays wliich diverge from each point
of the latter in a vertical plane — i.e. at right angles to the direction

CHAP. XVI.] ASTIGMATISM. 439

of the line — are brought to a focus on the retina ; while those rays
diverging in a horizontal plane, although not meeting on the retina,
do not render the picture of the line indistinct, because the diffusion
images resulting from them exist in the horizontal direction, and
consequently cover or overlap each other on the line, and therefore
are not seen, and do not confuse the sight. At the ends of the line
only (6, Fig. 170) do the diffusion images cause a fuzziness or make
the line seem longer than it is. In this case a vertical line {a, Figs.
169 and 170) seems indistinct, because, the horizontal meridian being
out of the focus, the diffusion images existing in that direction are
very apparent, as they are at right angles to the edge of the line.
On the other hand, in order to see a vertical stripe accurately, it
is necessary only that the rays diverging in a horizontal plane should
have their focus on the retina ; and, therefore, if an individual can
only see vertical lines distinctly at 6 metres we know that his eye
is emmetropic in the horizontal meridian (and probably myopic
in the vertical meridian). We do not, however, hear this complaint
as often as might be expected, because simple astigmatism is not
so common as one or other of the compound forms.

Astigmatic people do not generally see very distinctly, either
at long or at short distances.

Even in hypermetropic astigmatism the book is very often
brought close to the eyes, in order, by increasing the size of the
retinal image, to make up for its indistinctness.

Astigmatic individuals frequently suffer much from headache,
and sometimes from regular attacks of migraine with sickness, due
to constant effort to see distinctly, and correction of the astigmatism
often effects a cure.

It has been stated that epilepsy, hysteria, and neurasthenia, if
not capable of being actually produced by refractive errors, especially
by astigmatism, in persons with stable brains, may sometimes have
such errors as their exciting cause, where there is already a pre-
disposition to the disease.

All these signs and symptoms appertain to the rather high de-
grees of astigmatism. Slight degrees may cause no annoyance
beyond some indistinctness of vision ; and indeed slight degrees of
hypermetropic astigmatism often pass unnoticed until late in life,
when the accommodation begins to fail. But very low degrees of
astigmatism may give rise to symptoms in neurotic individuals.

440 DISEASES OF THE EYE. [chap. xvi.

The forms of Astigmatism most likely to cause annoyance are
those contrary to rule or with the axis obliquely placed.

We are often led to suspect and to seek for astigmatism when,
in examining the refraction with spherical glasses, we are able to
bring about some improvement of vision, but cannot obtain normal
V. with any glass, while there is no organic disease to account
for the defect. Also if, in examining with spherical glasses, we
find V. benefited equally by several glasses of considerable differ-
ence in power, even perhaps by convex as well as by concave glasses.

The ophthalmoscope affords an admirable means of diagnosing
astigmatism, and of determining its amount. Just as the astigmatic
eye cannot see horizontal and vertical lines equally well at the same
moment, so is an observer unable to see both the vertical and hori-
zontal vessels in the retina of the astigmatic eye simultaneously,
but must alter his accommodation to be able to see first one set of
vessels and then the other.

A comparison of the shape of the optic papilla, as seen in the
upright and in the inverted images, may also give a clue to the
presence of astigmatism. Inasmuch as the fundus oculi is very
much magnified in the upright image by the dioptric media through
which it is seen, and as this enlargement is greater in the direction
of the meridian of shortest focus (meridian of highest refraction),
which is most commonly the vertical meridian, a circular object,
such as the papilla, will seem to be of an oval shape with its long
axis vertical. But in the inverted image, if tlie principal focus of
the lens be closer to the eye than 13 mm. (anterior focus of the
eye), the magnification will be less in the meridian of greatest re-
fraction ; and here, consequently, the round optic papiUa is seen as
an oval with its long axis horizontal. If the principal focus of the
lens be farther from the eye than 13 mm., the magnification again
becomes greater in the meridian of greatest refraction, and the
oval again becomes vertical. Sometimes the papilla is really of an
oval shape, and not round, and then the diagnosis is readily made
by observing that in one image it is seen as an oval, while in the
other image it is circular. Care must be taken in the indirect
method not to hold the lens obliquely, as this would be sufficient to
make a circular disc appear oval, the long axis of the oval being in
the direction of the axis round which the lens is rotated.

In astigmatic eyes a crescent, similar to that seen in myopia,

CHAP. XVI.] ASTIGMATISM. 441

is often present at the margin of the optic disc. The length of the
crescent is parallel to the meridian of least refraction.

In cases of corneal astigmatism of high degree the image of
Placido's disc (p. 151), reflected on the cornea, shows ellipses instead
of circles, the short axes lying in the meridian of greatest curvature.

The Estimation of the Degree of Astigmatism and its Correc-
tion. — It is evident that to correct astigmatism the ordinary spheri-
cal lenses would be of little use, for they affect the refraction of the
light passing through them equally in every direction. CyHndrical
lenses (p. 404) are therefore employed, which refract light in one
direction only — viz. at right angles to their axes.

Subjective Method. — Although astigmatism is nowadays al-
most universally, in the first instance, estimated by means of the
ophthalmoscope, or by the astigmometer (p. 443), yet in order to
give the reader a clear idea of the matter in the simplest way, a
subjective method for its estimation will be now described, while its
objective estimation by aid of the ophthalmoscope (erect image and
retinoscopy) will be treated of in the next chapter.

Simple Astigmatism. — Snellen's Sunrise {vide diagram at end of
book), or some such diagram, is placed at 6 metres from the eye
(the other eye being excluded), and the patient is asked whether there
be any line which he sees much more distinctly and blacker than the
others, and can trace farther towards the central point. If that be
.so, he must be emmetropic in the meridian at right angles to that
line, provided his accommodation be at rest, and ametropic in the
meridian corresponding with that line.

In case the horizontal line below at each side be the distinct one,
the eye is em.metropic in the vertical meridian, and probably hyper-
metropic in the horizontal meridian, because the latter is generally
that of least curvature. Consequently, a convex cylindrical lens
held with its curvature horizontally (axis vertical) before the eye
will correct the defect. The highest convex cylindrical glass which
renders all the lines equally distinct and which gives the patient the
best possible distant vision will be the correcting glass. This would
be a case of Simple Hypermetropic Astigmatism (As. H.). If the
lens required be + 2 D Cyl., it would be As. H. 2 D ; and in pre-
scribing for the optician we would write " + 2 D Cyl. Ax. Vert."

If the central vertical line be the distinct one, then emmetropia
exists in the horizontal meridian, and probably therefore myopia in

442 DISEASES OF THE EYE. [chap. xvi.

the vertical meridian ; and a concave cylindrical lens held before the
eye with its curvature vertical (axis horizontal) will correct the de-
fect. The lowest concave cylindrical lens which gives the patient
the best possible distant vision will be the correcting lens. This
would be a case of Simple Myopic Astigmatism (As. M.). If the lens
be — 2'5 Cyl., it would be As. M. 2*5 D ; and for the optician we
should write '' — 2-5 D Cyl. Ax. Horiz."

The reader should now make a few experiments for himself with
cylindrical lenses, by means of which he can produce artificial astig-
matism in his own eye. Let him place Snellen's Sunrise figure
opposite his eye at a distance of about 4 to 6 metres. If he
now hold a -[- I'O Cyl. before his eye, with its axis horizontal, it
gives a myopia of TO D to the vertical meridian of the eye,
while the horizontal meridian remains emmetropic ; and con-
sequently, he will see the central vertical line of the diagram dis-
tinctly, while the horizontal lines will be indistinct. By placing
a — rO Cyl. with its axis horizontal before the eye, in addition
to the + I'O Cyl., the artificial astigmatism produced by the latter
is corrected, and the whole diagram becomes distinct. Every
other kind and degree of astigmatism can be similarly represented
by lenses and similarly corrected.

* Co7npound Astigmatism. — The spherical lens which corrects one
meridian having been found, one set of

TT 4 T)

lines will appear defined, and then the +
or — cylinder necessary to bring the re-

H. 5D. maining lines into focus will give the

amount of astigmatism. In the case

represented by Fig. 171 the order for the

Fig. 171. glasses would read ^' +4 D Sph.o+ 1 D

Cyl. Ax. Vert." ^ This is Compound

Hypermetropic Astigmatism.

In an analogous way the examination is made for Compound
Myopic Astigmatism, in which every meridian is myopic, but the
vertical meridian more so than the others.

Mixed Astigmatism. — In a case of mixed astigmatism, such as is
represented by Fig. 172, the correction can be made in two ways •
(a) by a Sph. — 3 D, which will correct the vertical meridian,

1 The sign O indicates '' combined with."

CHAP. XVI.]

ASTIGMATISM.

443

M. 3D

but will increase the liypermetropia in the horizontal meridian by

3 D, making it 8 D, which can then l^e corrected by combining a

cylindrical lens of + 8 D, axis vertical, with

the above spherical lens ; (6) by a spherical

+ 5 D, which will correct the horizontal

meridian, but will increase the myopia in H.D5

the vertical meridian to 8 D, necessitating

the combination of a — Cyl. lens of that

number with the + 5 D 8ph. For reading. Fig. 172.

writini)-, etc., an over-correction of the hori-

zontal meridian with + 8 D Cyl, thus rendering the eye myopic 3

D in every meridian, and enabling the patient to read at, or near,

his far point, might be the most suitable arrangement.

As it is necessary, in order to test the degree, etc., of astigmatism

accurately, that the accommodation be at rest, it is desirable, before

the examination for any of
Jt jk. y^"^ *^® hypermetropic forms in

young persons, to instil atro-
pine into the eye.

* Measurement of the
Degree of Astigmatism by

THE ASTIGMOMETER. — T h i S

is one of the most rapid and
satisfactory methods of de-
termining both the degree of
corneal astigmatism, and the
position of the meridians of
greatest and least refraction.
The cornea reflects images
of objects in the same
manner as a convex mirror,
and the smaller the radius of
curvature the smaller will
be the image of any given object. It is easy to calculate the radius
of curvature of the cornea, if the size of the object, its distance
from the cornea, and the size of the corneal image be known. The
only difficulty lies in the measurement of this image ; and it has been
found that the best method of effecting this is to double the image
by means of prisms, and then to alter the strength of the prism until

Fig. 173. — The Astigmometer.

444 DISEASES OF THE EYE. [chap. xvi.

the two images just come into contact. When this has taken place,
a displacement equal to the size of the image has been produced.
The amount of displacement, and hence the size of the image, can
easily be calculated. This is the principle of the astigmometer
(Fig. 173).

In order to measure the degree of astigmatism by this instru-
ment, we do not require to know the radius of curvature of the
cornea, but need merely find out the difference in refractive power
between tlie meridians of greatest and least curvature, and this
the instrument enables us to do in a few seconds without any
calculation.

The Astigmometer. — It consists (Fig. 173) of a telescope {f) con-
taining a double refracting prism between the object glasses, and
two reflectors or mires {k and I), movable on an arc (m), which is
fixed to the telescope tube. The latter turns on its own axis, and
enables the arc to be placed in any meridian, its position being indi-
cated on a graduated circle {g). The patient places his chin on the
rest d, and looks into the tube at /, the eye which is not under
observation being covered by the disc e. The surgeon then looks
through the telescope at w, turns the arc m into a horizontal position,
and observes the corneal images of the mires, which he gets into focus.
He then moves the mires until the central images just come intjo con-

tact ; the four images will then occupy the relative positions shown in
Fig. 174. The arc is then rotated into the vertical meridian, and if
the curvature of the cornea in this meridian be the same as in the
horizontal meridian, the central images will still appear to be in con-
tact ; but if the radius of curvature in the vertical meridian be smaller,
the intervals a to h and ci to V will diminish, and consequently the
central images will overlap, as in Fig. 175, each step of a' representing
a difference of 1 Dioptre. So that in this case (Fig. 175) there would

CHAr. xvi.l ASTIGMATISM. 445

be au astigmatism of 2 1), and the greatest refraction would be
in the vertical meridian.

It is generally desirable to begin with the arc placed in the hori-
zontal meridian. If the axes of the meridians of
greatest and least cnrvature are obliqne, then the
images will not lie in one line, and the arc must
be turned until they are on a level. An index
which moves on the circle <j (Fig. 173) gives the
position of the axes. It will be seen from the
above description that the astigmometer merely
registers the amount of astigmatism, but does not enable us to
estimate the general refraction of the eye. Moreover, it is the
corneal astigmatism alone which is determined, and it will be found
in most cases to differ only slightly from the total astigmatism. A
useful modification in the mires consists in making them of com-
plementary colours, for instance, one red and the other green, the
overlapping portion then appears w^hite and is easily seen. Another
great advantage which these coloured mires possess is the absence
of dispersion, due to the use of mono-chromatic light, which renders
the appreciation of the contact of the images much more delicate.
The latter is the instrument used at the Victoria Hospital, and it
facilitates the observations considerably.

* Lental Asticjmatism. — The astigmatism of the lens when at
rest is supposed to be about 0"75 D, and contrary to the rule, and
it tends therefore to correct or diminish corneal astigmatism with
the rule. This assumption is based on the fact, that often, when
there is no subjective astigmatism, the astigmometer shows a corneal
astigmatism of 0*75 D with the rule, which the lental astigmatism
presumably corrects. The theory also accounts for the fact that
the astigmometer over-estimates the total astigmatism by 0'5 D or
0*75 D when with the rule, and under-estimates it by the same
amount when against the rule ; because in the latter instance the
lental astigmatism must be added to that of the cornea, whereas
in the former case, it must be deducted from it. This lental astig-
matism may be caused by the shape of the lens, or by an obliquity
in its position. A difference between the subjective or total astig-
matism, and that of the cornea as measured by the astigmometer,
can also be accounted for by the fact that the visual line does not
pass through the centre of the pupil, and therefore the portion of

446 DISEASES OF THE EYE. [chap. xvi.

the cornea iiiccisured by the astigmometer is not exactly the same
as that wliich produced the retinal image. These discrepancies,
however, do not detract materially from the practical value of the
instrument.

Disturbances of vision due to astigmatism often make their
appearance for the first time at middle age or even later, and are
then apt to be mistaken for amblyopia. In such cases the cornea
has been astigmatic all through life, but the defect has been masked
by a compensating astigmatism of the crystalline lens, produced,
it is supposed, by an unequal accommodative contraction of the
ciliary muscle. When, as life advances, the amplitude of accom-
modation diminishes, the power of the ciliary muscle to produce
this active compensatory lental astigmatism also diminishes, and
finally disappears, and then the corneal astigmatism becomes mani-
fest ; or, in astigmatic individuals the astigmatism may alter in
degree at this time of life. Astigmatism '" against the rule " is
more common in old than in young persons. Under atropine, too
astigmatism may appear, the existence of which was not previously
known. This is termed active, or dynamic, lental astigmatism.

Prescription of Cylindrical Lenses. — The required position of the
axis of a cylinder in a prescription is indicated by a line at the
extremity of ^vhich a number indicates in degrees its inclination
to the vertical or horizontal, e.g. 2 D. Cyl. ax. p^°. In sphero-
cylinders one surface of the glass is spherical and the other cylin-
drical. Since the axis of cylindrical lenses must occupy a definite
and unalterable position before the eyes, spectacle frames or rigid
spiral-spring pince-nez should be ordered, and not folders. When
first worn, cylindrical glasses frequently appear to cause distortion
in tlie shape of objects, and unpleasant sensations of giddiness ;
these symptoms, however, disappear Avith a little perseverance in
the use of the glasses.

Irregular Astigmatism.

In irregular astigmatism, the refraction of the eye differs not
only in different meridians of tlie eye, but even in different parts
of one and the same meridian. It is frequently due to irregularities
of the surface of the cornea, the result of former ulcers, and also
sometimes to irregular refracting power in different parts of the

CHAP. XVI.] ANISOMETROPIA. 447

crystalline lens. It cannot be corrected. Its presence can be de-
tected by a distortion and irregular movement of the optic disc
when the lens is moved during the indirect method of examining
with the ophthalmoscope, by Placido's disc, and also by an irregular
shadow in retinoscopy. In some cases, there is a certain amount
of regular astigmatism combined with it, correction of which may
improve the vision.

* Anisometropia. ^

By this term is meant a difference in the refraction of the two
eyes, one being myopic, hypermetropic, or astigmatic, while the other
is emmetropic, or ametropic in a way different from its fellow. It
has been shown that in these cases the same amount of accommoda-
tion takes place in both eyes. So long as the difference in refraction
is but slight (say 1 D or 1*5 D), it is generally possible to give the
correcting glass to each eye. When the difference is considerable
it is often impossible fully to correct each eye, because, binocular
vision having never really existed, the patients are unable to tolerate
the presence of a clear image on each retina. We must then be
content with correction of the least ametropic eye, or of that one
which has the best vision ; or, we may partially correct the most
ametropic, and fully correct the least ametropic eye. If one eye
be emmetropic no correction may be necessary. Each such case
must be dealt with as it permits.

Estimation of the Refraction by Aid of the Ophthal-
moscope.

Estimation of the Refraction by the Inverted Method. — The position of
the inverted image, in other words its distance from the lens used, depends
on the strength of the lens, its distance from the eye, and on the refrac-
tion of the eye. If the number of the lens and its distance be fixed, the
refraction alone causes the alteration in the position of the inverted image.
In Em., the emerging rays being parallel, the image is formed at the focus
of the lens ; in M., the rays being convergent, the image is closer to the
lens ; and in H, it is farther away, owing to the divergence of the rays
coming out of the eye. The methods of measuring the refraction which
are based on these principles have not, however, come into general
practical use.

^ d, priv. ; Laos, like ; /Lurpov, a measure.

448

DISEASES OF THE EYE.

[chap. XVI,

By the Direct Method at a distance of about 50 cm. from the
observed eye into which light from the ophthalmoscope mirror is
thrown, the observer will be able to make the qualitative diagnosis
of the refraction. If he can see some of the details of the fundus,

the eye is either myopic or hypermetropic ; but if it be emmetropic,
or have M. of less than 2 D, he will be unable to see any detail.
The explanation of this is that, in myopia, the rays, from any one
point on the retina, emerging from the eye, form an inverted image
at the far point of the eye in the air, and this image can be seen by
the observer who accommodates his eye for that point. In hyper-
metropia, the issuing rays being divergent pass into the observer's
eye, and, by an effort of accommodation on his part, he will see an
upright image of the portion of the patient's fundus oculi from which
they come. But in emmetropia, or low degrees of ametropia, in-
asmuch as the rays come out either parallel or very nearly so, those
from any two points {m, n, Fig. 176) at a short distance from each

Fio. 177. — Apparent motion of fvindiis with tlie observer in H.

other in the fundus on emerging from the eye diverge quickly from
each other, and the observer a little way off (at A) receives none
of them into his eyes, or obtains only an indistinct image or red
glare. If he go very close to the eye he can see details.

CHAP. XVI.] OPHTHALMOSCOPE AND REFRACTION. 449

If, on the observer moving his head from side to side, the vessels,
etc., of the observed fundus move with him, the case is one of hyper-
metropia, if against him it is a case of myopia. In H. (Fig. 177) the
observer at sees an erect image of the fundus at F behind the plane
of the pupil, P, and it appears to be situated at A ; on moving the
head to 0', the line of vision is F, and F appears to be at A'. In
myopia (Fig. 178) the image is an inverted one lying in front of the

Fig. 178, — Apparent motion of fundus against the observer in M.

plane of the pupil at F, and when the observer changes to 0' the
image appears to be in the pupil at A'.

* For the quantitative determination of ametropia a refraction
ophthalmoscope is required. This instrument is provided with a
number of convex and concave lenses capable of being brought into
position behind the sight-hole in rapid succession by a simple
mechanism ; and also with a tilted mirror which avoids the necessity
of holding the ophthalmoscope in an oblique position, and thus the
lenses are maintained in a position at right angles to the visual
axis of the observer. The direct method, close up to the patient's
eye, is employed.

It is necessary, in the first instance, that the observer be acquainted
with the nature of his own refraction.

* // the Observer he Eminetropic he can see the fundus oculi of an
emme trope in the upright image without any lens, provided he go
close enough, as the parallel rays coming from the examined eye
will be focussed on his retina, because his eye is adapted for parallel
rays.

In order to see the fundus oculi of a hypermetrope without any
effort of accommodation, he must place such a convex lens behind
his ophthalmoscope as will render the divergent rays coming from
the patient's eye parallel before they pass into his eye. This lens is
the measure of the patient's hypermetropia, because it shows how
many dioptres the eye wants of being emmetropic. The lens which
29

450 DISEASES OF THE EYE. [chap. xvi.

makes the divergent rays coming from the patient's retina parallel,
would also give to parallel rays passing into the eye such convergence
that they would meet on the retina — i.e. it would correct the hyper-
metropia if the patient were examined with test-types and glasses
(p. 431.) (See Fig. 162.)

The emmetropic observer can of course see the fundus oculi of a
hypermetrope by the direct method without the correcting glass, if
he use his accommodation to overcome the divergence of the rays
coming from the observed eye, and this is usually the case in the
lower degrees of hypermetropia. The observer generally relaxes
his accommodation according as he substitutes convex lenses for it,
until he reaches the strongest lens with which he can distinctly see
the fundus. This is the correcting lens.

To see the fundus oculi of a myope, the emmetropic observer
must place a concave glass behind his ophthalmoscope, in order that
the convergent rays coming from the observed eye may be made
parallel before they pass into his eye ; and the lowest concave lens
which enables him to see the fundus oculi distinctly is the measure
of the myopia (p. 418), as showing by how many dioptres it is in
excess of emmetropia.

The emmetropic observer cannot possibly see the fundus oculi
of a myope without the correcting glass, as the rays are brought to
a focus in front of his retina, and if he use his accommodation he
merely makes them still more convergent. But, by means of an
effort of his accommodation he can see the myopic fundus with a lens
which over-corrects the myopia, and hence the importance of
selecting the weakest concave glass with which the fundus is distinctly
seen.

If the observer be ametropic, he may either correct his ametropia
by wearing the suitable lens, and then proceed as though he were
emmetropic, or else, and which is perhaps the better plan, he must
allow for the amount of his ametropia.

For example : —

* The Hypermetropic Observer of say 3 D requires a -f lens of 3 D
in order to see an emmetropic fundus oculi, this lens going altogether
to correct his own defect. If in order to examine the fundus of
another eye he require a -j- lens of 6 D, the examined eye must be
hypermetropic 3 D, the other 3 D going to correct the observer's
H. If he be able to see the fundus oculi under observation without

TftAP. xvr.] OPHTHALMOSCOPE AND RKFR ACTION. 45J

any lens, it shows that the eye has an excess of refraction correspond-
ing with the want of refraction in his own eye — that is to say, it is
myopic 3D. If he require a concave 2 D, his want of refraction —
his hypermetropia — is not enough by that number of dioptres, and
he has to do with an eye which is myopic 5 D (3 D + 2 D). Again,
if he can see the fundus distinctly with a + lens, say + 1 D, which
is less than his own correcting glass, this shows that the eye he is
examining is myopic, but myopic to a lesser degree — in this instance
by 1 D — than he himself is hypermetropic, and the examined eye
here would be M. 2*0 D {i.e. S'O-l-O).

If the Observer be myopic the same method of reasoning applies.

* The Existence and Degree of Astigmatism 7nay be Determined
mth the Ophthalmoscope. — We know that astigmatism is present, if
in the upright image we see the upper and lower margins of the disc
and the horizontal vessels well defined, while the lateral margins
and the vertical vessels are blurred, or vice versa. Again, we know
that astigmatism is present if, in comparing the shape of the optic
disc in the upright and inverted images, we find it to be an oval
with its long axis perpendicular in the former, and with its long axis
horizontal in the latter, showing that the refracting media are more
powerful in the vertical than in the horizontal meridian.

We may ascertain the kind and degree of astigmatism as
follows : —

If in the upright image with relaxed accommodation, we can see
the retinal vessels in one meridian distinctly, while in order to see
those in the opposite meridian a concave or convex lens behind the
ophthalmoscope is required, we know that the case is one of simple
myopic or hypermetropic astigmatism ; the emmetropic meridian
being that at right angles to the vessels ^ seen without any lens, and
the number of the lens indicating the amount of ametropia in the
other meridian.

If, in the two principal meridians, two concave lenses or two
convex lenses of different strength be required, we have to deal with
a case of compound astigmatism, myopic or hypermetropic ; the
greatest error of refraction being in the meridian at right angles to
that one, the vessels of which are made distinct by the strongest lens.

^ The vessels may be regarded as lines, and the explanation given on
p. 434 applies to them also.

452 DISEASES OF THE EYE. [ohap. xvi.

If a concave lens be required to bring into distinct view the
vessels in one meridian, while a convex lens is required for the
opposite meridian, tlic case is one of mixed astigmatism. Myopia
exists in the meridian at right angles to that in which the vessels
are brought into view by the concave lens, and hypermetropia exists
in the opposite meridian.

Retixoscopy.

Eetinoscopy, or the Shadow Test, is the most useful method for
determining the refraction by the ophthalmoscope. It consists in
illuminating the eye with the plane or concave mirror at a distance

Fig. 179. — Motion of the virtual image in rotation
of a plane mirror.

of a little over a metre, or more, and then moving the light into
different positions by rotation of the mirror round an axis lying in
its own plane, the observer noting on which side of the illuminated
pupil the shadow appears, and in which direction it moves across
the pupil.

Direction of Displacement of the Image when a Mirror is rotated round
an Axis lying in the Plane of the Mirror. — Wlien a plane mirror is rotated,
the image of the source of light moves in a direction opposite to that
in which the mirror is rotated. In Fig. 179 when the mirror is rotated
from Ml to M2 the image of the light, L, will be found on the per-
pendiculars to the mirror, j\Ii and Mj, at Ii, and lo. The cones of rays
emerging from these images, ai ui and 62 bz, will move with the rotation
of the mirror as indicated by arrow B, while the images have moved in
the opposite direction, shown by arrow A. When a concave mirror is
rotated, the image moves in the same direction as the mirror. In Fig. 180
when the mirror is in the position M^, the image of L is formed at I^, on

CHAP. XVI.]

RETINOSCOPY.

453

the secondary axis passing through the centre of curvature C^ ; and, on
rotating the mirror into the position M^, the corresponding image will be
found on the secondary axis L C^, say at T-, the change of position of

Fig. 180.

-Motion of inverted iinage in rotation
of a concave mirror.

the image being in the direction of the arrow, and with the movement of
the mirror.

Theory of Retinoscopy. — In the explanation which follows, the con-
cave mirror is supposed to be used. In Fig. 181, rays from the light, O,
placed at the side of the patient's head, strike the mirror, A, which forms
an inverted aerial image. A', as explained in chap. ii. This image is now
the immediate source of light, rays from which, entering the eye, are made

Fig. 181. — Retinoscopy with concave mirror. Shows that the real
movement of the retinal image is the same in all conditions of refraction.
1. Motion of mirror, or of light area on patient's face. 2. Motion of
aerial image produced by mirror (immediate source of light). 3. Real
motion of retinal image of light.

to converge toward their conjugate focus, /, on the secondary axis, A' N /,
passing through the nodal point, N. If the retina be at M', or in other
words, if the eye be myopic, with its far point at A', a distinct and bright
image of the light A, will be formed on the retina at /. In any other

454 DISEASES OF THE EYE. [chap. xvi.

condition of refraction such as emmetropia, E., hypermetropia, H., or
any higher degree of myopia, M., a circle of diffusion, c d, is formed by each
point of light, and a blurred image is the result ; so that the area of illu-
mination is less bright, and its bovindary less defined. The farther the
retina is from /, the less will be the brightness and the definition of the
margin of the illuminated area.

Now let the mirror be rotated from A to B, the movement of the light
area, surrounding the eye, on the patient's face will, of course, take the
same direction, indicated by the arrow I. As explained at the beginning
of this chapter, the immediate source of light will move to B', shown by
arrow 2, and its image will be formed, more or less distinctly, on the re-
tina, at the point at which it is intersected by the secondary axis B' N 6.
The retinal image, therefore, will move in the direction of arrow 3, from
a to 6, and this motion, as the figure shows, is the same in all positions
of the retina. The real motion of the retinal image of the light in the
observed eye is therefore independent of the refraction of the eye, and
is in a direction contrary to that of the immediate source of light, and also
against the motion of the concave mirror.

The observer cannot, however, see directly what is taking place on
the retina of the observed eye, since he can only examine it through its
refractive media. It remains, therefore, to determine the effect of tho
refraction of the observed eye on the motion as it appears to the observer ;
tliis may be called the apparent movement. What the observer sees is
the image, real or virtual, formed by the observed eye, at its conjugate
focus or far point, and therefore the apparent movement will depend on
the position of the far point.

Fig. 182. — Retinoscopy, with concave mirror, in hypriin'>tropia. 1.
Motion of mirror. 2. Motion of immediate source of light. 3. Real
motion of retinal image. 4. Apparent motion of retinal image.

In H (Fig. 182) the immediate source of light, A, illuminates a portion
of the retina at a. The rays e, f emerging from this point diverge, and
entering the observer's eye seem to him to come from a, the far point
of the hypermetropic eye. When, by reason of a rotation of the mirror
to B, the light moves to B', its retinal image 6, seems to be at /3. The
illuminated area seems therefore to have moved in the direction of arrow
4 — that is, (Kjdlnst \\w mot ion of the mirror (arrow 1).

CHAP. XVI.]

RETINOSCOPY.

455

In Em. similarly, the emergent rays are parallel, and the image is
projected by the observer to a position behind the eye under examination.
Stated simply, in both cases an erect image of the fundus is seen, there-
fore no reversal of the rays takes place between the eye of the observer
and that of the person under observation ; and consequently, the apparent
motion is the same as the real. As the light moves from a to & and so
passes on, the pupil will first appear to become darkened above, and the
shadow will move across it as shown in the circle P.

Fig. 1 83. — Retinoscopy with concave mirror in Myopia. Numbers as

in Fig. 182.

In Myopia, on the other hand (Fig. 183), the rays from the illuminated
area a converge to form an inverted image at a, the far point of the eye,
situated on the secondary axis A'Na. When the immediate source of
light moves from A' to B', the apparent movement is from a to /3. In
this case a reversal of the relative position of the rays takes place, before
they enter the observer's eye ; the upper rays become the lower and
vice versa. Hence this is sometimes called the point of reversal. In this
case the darkness will appear first at the lower edge of the pupil, and will
travel upwards as indicated in the circle P, that is to say, in the same
direction as arrow 1, with the movement of the concave mirror.

The above explanation only holds good in myopia, when, as in the
figure, the far point of the eye under observation lies in front of the ob-
server's eye. If, however, the far point be situated farther back than the
observer's eye, the rays will not have met to form the inverted image,
but will enter his eye retaining the relative positions which they bore
to each other on emerging from the eye under observation ; consequently,
the observer will see an erect image of the illuminated area, and the move-
ment will be as in H. and Em., namely, against the concave mirror. It
is obvious, that the lower the degree of myopia the farther away the
observer must be in order that he may see the reversal of the movement.

An error of refraction in the observer's eye does not influence the
apparent movement, but merely renders the appearance more or less
distinct to him. It should also be stated, that as the observer accom-
modates for the patient's pupil, and not for the far point of the retina
of the patient, the image seen is always more or less diffuse.

Retinoscojyy ivith the plane fnirror. — The immediate source of light
in the case of a plane mirror is a virtual upright image behind the mirror

456 DISEASES OF THE EYE. [chap. xvi.

(Fig. 179). It moves in the opposite direction to the motion of the mirror,
and not with it, as in the case of the concave mirror. Hence the real
movement of the retinal image in the patient's eye will be with the mirror.
The apparent movement will, therefore, be the same ; that is, with the
mirror, in Em,, H., and in low M., where the point of reversal is farther
away than the observer. In higher degrees of M., with the point of
reversal nearer than the observer, the real motion will be reversed, and
hence the apparent motion will be against the motion of the mirror.

Degree of illumination, form, and rate of movement of the shadow. — As
showai in Fig. 181, when the retina is at the conjugate focus of the immedi-
ate source of light, the iUumination is at its greatest. The farther away
the retina is from the conjugate focus, that is to say, the higher the H.
or M., the larger must be the area over which the light is spread, and
therefore the more defective the illumination becomes, and the less defined
and the fainter is the edge of the shadow.

The higher the error of refraction, the nearer to the eye is the far point,
and the smaller is the remote image ; but with the smaller image a larger
field is obtained, and more of the circular edge of the shadow is seen ;
hence, the latter appears crescentic. In the lower degrees of ametropia
and more especially in Em., the magnification is much greater and the
field is smaller. Therefore, a small portion only of the large circular
edge is visible, causing the shadow to appear less crescentic and more
linear.

The apparent rate of movement depends more on the degree of magni-
fication of the remote image, than on the real rate of movement of the
retinal image. The less the magnification the slower the movement
appears, for instance in Figs. 182 and 183, if the far point were in each case
at c, the light would have to travel only from d to c, instead of from" a to
^, with the same rotation of the mirror. At c, therefore, it would appear
to travel a shoioer distance in the same time, and would therefore appear
to move slower. The higher the ametropia, then, the slower appears to
be the movement of the shadow.

Practice of Retinoscopy with the Concave Mirror.— The examina-
tion is conducted in the dark room. The light is placed at the side
of, or above the patient's head, and behind the level of his eye, so
that the latter may be in the shadow. If the concave mirror be
used, the observer sits at a distance of r25 m. in front of the patient.
The focal length of the mirror should be about 22 cm., and the
diameter of the sight-hole about 3 mm. The observer should correct
any error in his refraction. The light is then thrown into the
patient's eye, near the region of the macula lutea, but not on it,
unless the pupil be dilated by atropine, otherwise the pupil becomes
too small and the red reflex too faint. The observer accommodates
for the pupil, and rotating the ophthalmoscope, usually in the hori-
zontal and vertical meridians, he observes the shadow at the cir-

CHAP. XVI.] RETINOSCOPY. 457

cumference of the pupil. When the mirror is rotated — say, in the
horizontal meridian — the edge of the shadow will be vertical, it
will move horizontally, that is at right angles to its edge, and it
will indicate the refraction of the horizontal meridian. If the move-
ment of the shadow be with the movement of the mirror, or with
the light on the patient's face, myopia is present ; if it move against
the mirror, Em., H., or M. of less than 1 D is present.

The reason why the shadow is against the mirror in cases of
less than 1 D is that, in M. of 1 D, the inverted image or point of
reversal of the emerging rays is situated at the far point of the
patient's eye, namely 1 m. in front of the patient, and the observer
being 25 cm. farther away sees this inverted image. But if the
myopia be less than 1 D, the far point, or point of reversal, lies
behind the observer's head, and he now sees an erect image as in
Em. or H., and the apparent movement is then the same as in Em.
or H., namely against the mirror.

In order to estimate the error of refraction, a trial spectacle-
frame is put on the patient's face. If the shadow move with the
mirror, we know at once the eye is myopic. To find the degree of
myopia, the observer puts a low concave-glass (say — ID) into the
frame ; and if the shadow still move with the mirror, he puts in a
higher number (say — 1*5 D), and so on until he comes to a glass
which makes the image move against the mirror. If this be — 3D,
the myopia is 3 D. It might be supposed, as the shadow now moves
against the mirror, that this glass over-corrects the myopia ; but
this is not so, because, as already explained, when the myopia is
very low the image is formed close to the observer's eye, or behind
his head, and he consequently gets a shadow moving against the
mirror, although low myopia, and not emmetropia, is present. Con-
sequently, — 0'5 D, or — ID, has to be added on to the lens, which
gives the effect of no distinct shadow ; or rather, by the above plan,
it is not deducted from the lowest lens, which makes the shadow
move against the mirror.

If the shadow move against the mirror, we have to determine
whether the eye is emmetropic, hypermetropic, or slightly myopic.
Should the illumination be bright, and the shadow well defined,
the eye is emmetropic, or not far removed from it ; and if the shadow
be ill defined and crescentic, we may feel sure the eye is highly
hypermetropic. We first put on -|- 1 D, and if the motion be still

458

DISEASES OF THE EYE.

[chap. XVI.

against the mirror, the case is one of hypermetropia, and higher
numbers are at once proceeded to, until that one is reached which
causes the shadow to move with the mirror. The measure of the
hypermetropia is 1 D less than tlie glass so found, for it has evidently
over-corrected the defect, having made the eye 1 D myopic.

If, however, on putting on -f 1 I^ we find the shadow to move
with the mirror, we change it for -f ^^'5 D ; and if still the motion
be with the mirror, the eye is, beyond doubt, slightly myopic, — 0*5
D or so. But if with + 1 D the shadow move with the mirror,
while with-f 0'5 it continue to move against it, the eye is emmetropic.
In astigmatism, the light being differently
focussed in two meridians at right angles to
each other, and being drawn out into a line
or oval of diffusion, causes the illuminated
area to appear like a band. The boundary
of the shadow therefore is more of a straight
line than a circle. If the axes of the astig-
matism be oblique, the edge of the shadow
will lie in one of the meridians, and the
movement will take place in the other one —
according to the direction of the rotation of

Fig. 184.— If the
ruler C D be moved
behind the circle in
the direction of R,
its obHquity being
preserved, it will ap-
pear to a person who
sees only the portion
inside the circle, to
move in direction A.

the mirror. Even if the mirror be not
rotated in the direction of the meridian of
greatest or least refraction, the edge of the
shadow will nevertheless lie in the direction
of one of these meridians, namely in that
which is nearest to the axis of rotation, and
will appear to move in the meridian at right angles to it. This is
due to an optical illusion explained by Fig. 184.

It may be found that in opposite meridians there is a difference
in the motion of the shadow, and this indicates the presence of
astigmatism. When the difference is one merely of rapidity of
motion, or of intensity of illumination and shadow, it is either
simple hypermetropic or compound astigmatism. But if in the two
meridians there be a difference in the direction of the motion, then
it is either simple myopic or mixed astigmatism.

In some rare cases the refraction is different at opposite sides
of the pupil, and a double shadow is seen. These shadows move
simultaneously in o})posite directions ; that is. towards or away

CHAP. XVI. 1 RETINOSCOPY. 459

from each other, like the blades of scissors, and hence the condition
is known as " scissors movement." In conical cornea, an irregular
or triangular shadow is seen, with its apex near the centre of the
pupil ; it rotates round its apex with the movements of the mirror.
In irregular astigmatism, the shadow appears broken up very irregu-
larly, and different portions of it move in various directions.

In retinoscopy the best method of ascertaining the degree of
astigmatism and its correcting glass is to correct each of the prin-
cipal meridians separately with spherical lenses. In compound
astigmatism, the difference between the two lenses found indicates
the degree of astigmatism, and also the cylindrical lens which, com-
bined with the correcting spherical lens for the least ametropic
meridian, is required to neutralise the defect. In mixed astigma-
tism, the addition of the two numbers gives the cylindrical lens,
while one or other of them, usually the — D, is used as the spherical
lens.

Retinoscopy with the plane mirror. — As explained on p. 452,
the immediate source of light moves in a direction the reverse of
that which is produced by the concave mirror ; therefore, the appar-
ent movement is ivith the mirror in H., Em., or low M., and against
it in the other degrees of M. It will be noticed that this is the same
as the apparent movement of the vessels when the observer moves
his head (p. 449). The advantage of the plane mirror is, that the
observer can stand farther away from the patient, and thus diminish
the ertor of observation. If, for example, the distance be a little
more than 4 m. when the shadow moves with the mirror, the ob-
server know^s, if M. be present, it must be less than 0*25 D. He
has still to decide whether this indicates E. or H. He does so by
putting a low + lens (say + 0*25) before the patient's eye, and if
then, standing at a distance of 4 metres, the motion be altered by
this glass to one against the mirror, he knows that the eye has
not a hypermetropia of 0*25 D, consequently that it is emmetropic.
But if this lens does not at that distance cause a change in the motion
of the shadow as originally obtained, the eye must be hypermetropic
to at least the extent of 0'25 D ; and, in order to ascertain how much
more of H. than this may be present, it is now only necessary to
continue increasing the strength of the lens in front of the patient's
eye, until one is reached which, at 4 metres from the eye, produces
the myupic motion. The observer knows that he has now slightly

460

DISEASES OF THE EYE.

[chap. XVI.

over-corrected the hypermetropia of the eye, and that the next
lens lower is its measure.

A plane mirror of 4 cm. diameter, and of which the sight-hole
is 4 mm. in diameter, is the pleasantest to use for retinoscopy.

ANOMALIES OF ACCOMMODATION.

Presbyopia.

This is a diminution in the amplitude of accommodation (p. 6),
which commences at an early age, and is due to natural changes

^.r .w ,?r

4^ .frj rir

e.f m 7J

Fig. 185.

taking place slowly in the crystalline lens. It might not, therefore,
strictly speaking, be regarded as an anomaly. The power of ac-
commodation commences to diminish in early childhood, the near
point beginning then to recede from the eye. The accompanying
diagram of Bonders (Fig. 185), illustrates the decrease from the
tenth year of age, and indicates the amplitude of accommodation
at different ages.

The numbers at the top indicate the ages in years, those on the
left the amplitude of accommodation in dioptres. The curve r r

CHAP. XVI.] ANOMALIES OF ACCOMMODATION. 461

shows the refraction of the eye when in a state of rest. This is
unchanged until the fifty-fifth year, when it begins to diminish ; the
emmetropic eye then becoming hypermetropic, the hypermetropic
eye more hypermetropic, and the myopic eye less myopic. The
curve p p shows the positive refracting power of the eye, corre-
sponding with the punctum proximum, and its gradual diminution
as life advances, and how at the age of 65 it becomes even less than
the minimum refraction in former years. The two curves meet
at the age of 73, and then all power of accommodation ceases. The
number of dioptres included between the two curves on the vertical
line corresponding with any given age represent the amplitude of
accommodation at that age — e.g. at 30 years of age the amplitude
is 7 D ; at 50 years it is only 2*5 D. The amplitude of accommoda-
tion is the same at the same age in all forms of ametropia, as well as
in emmetropia.

The cause of presbyopia lies chiefly in a progressive change in
the crystalline lens, which becomes less elastic and more homo-
geneous in its different layers, and refracts light less strongly than
before. In more advanced life, diminished energy of the ciliary
muscle probably becomes a second factor in the production of
presbyopia.

The near point gradually recedes from the eye until it reaches
a distance beyond that at which the person usually reads, writes,
sews, etc. Employments of this kind then become difficult, because
the retinal images are too small to be clearly discerned, owing to the
increased distance at which the work must be held from the eye ;
and, in order to make up for this smallness of the images, the in-
dividual is often seen to improve their brilliancy by procuring
stronger light.

Presbyopia [TrpeajSvs, an old man ; wi/^) was defined by Donders
to be present when the near point lies at more than 22 cm. from the
eye, and we correct it by giving such a convex glass for reading, etc.,
as will bring the near point back to 22 cm. Now in order to focus
an emmetropic eye for that distance a positive refracting power
{p) of (-Y/- = ) 4'5 D is necessary, and if the eye have not so much
accommodation, a convex glass must be given to it of such power
as will bring p up to 4*5 D ; and this lens is the measure of the pres-
byopia. At the age of 40 {vide Donders' diagram. Fig. 185) the eye
possesses a positive refraction of just 4*5 D ; and therefore from this

462 DISEASES OF THE EYE. [chap. xvi.

age presbyopia is said to commence in emmetropic eyes. The
presbyopia, then, is equal to the difference between the accommo-
dative power possessed by the eye and 4'5 D, and the number thus
found is the correcting glass for the presbyopia. The distance of
22 cm. is rather close to the eyes for the comfort of most people,
and 33 cm. is more commonly taken as the reading distance. Pres-
byopia on the latter assumption is postponed for two or three years.

The glass required in presbyopia must also depend on the nature
of the patient's work, which, of course, may require to be placed at
some definite distance. This distance, the refraction of the eye, and
the amplitude of accommodation (age of the patient), will determine
the number of the glass which must be prescribed in each case.

It is important that in prescribing glasses for presbyopia, if there
be any hypermetropic astigmatism present, it should be corrected
by the suitable + cylinder lens added to the spherical glasses. It
is also important that the glasses should be carefully centred for the
reading distance — i.e. that the visual lines, when they are converged
to the distance at which the work is held, should pass through the
optical centres of the glasses. The glasses must therefore be closer
together than distance glasses, and also tilted forwards at the top,
so that they may be at right angles to the visual axes. Moreover,
if there be any insufficiency of the internal recti, it will be for the
patient's comfort to decentre the lenses slightly inwards.

The following table indicates the presbyopia of the emmetropic
eye : —

Age.

p. required.

p. existing.

Presbyopia.

4-5

3-5

4-5

2 5

2-0

1-5

3-0

4-5

0-5

4-5

0-25

4-25

-ro

4-5

-1-75

6-25

-2-5

7-0

It is hardly necessary to point out that presbyopia comes on at
a much earlier age in hypermetropes than in emmetropes ; while in
myopes its advent is postponed ; or, in the higher degrees of myopir
it may not come on at all. The hypermetrope of 3 D would be
presbyopic at the age of 27 ; because, in order to arrive at the 4*5 D

CHAP. XVI.] ANOMALIES OF ACCOMMODATION. 403

of positive refraction required, he must have an amplitude of
accommodation of (3 D -f "^'^ D) 7 "5 D, and this he has up to
that age only (Fig. 185).

The myope of 4"5 D can get along until something over 60 years
of age without any glass for reading {vide above table). At 65, if he
were emmetropic, he would have presbyopia of 4*25 ; consequently
he will now require a -|- glass of only 0"25 D.

Persons who have worn full myopic correction constantly need
to have the power reduced for reading at the presbyopic age.

Presbyopia must not be mistaken for slight paralysis of accom-
modation. They are distinguished by the fact that in the former
the amplitude of accommodation corresponds with the age of the
patient as given in Bonders' table, and the difficulty of near vision
comes on gradually.

When presbyopia is associated with ametropia, which requires
correction for distance, bifocal lewises are very convenient. A thin,
oval or circular, lens (called a paster) representing the addition re-
quired for near vision is ground, or cemented on to the lower part
of the distance glass, or is inserted between the two portions of
which this is formed. The size of the reading portion should be
about 12 mm. broad, by 8 mm. high, and its upper border should
be a few millimetres below the optical centre of the distance lens.

Paralysis of Accommodation (Cyclopegia).

This may be partial or complete, and one or both eyes may be
affected. It is usually combined with paralysis of the sphincter
iridis (mydriasis), and the condition is then called ophthalmoplegia
interna ; but it is also seen without paralysis of the sphincter, and
either alone or with paralysis of some of the orbital muscles supplied
by the third pair, which also supplies the ciliary muscle — rarely with
paralysis of the external rectus.

The Symptoms are similar to those of presbyopia, but they appear
rather suddenly. They give inconvenience to the patient according
to the state of his refraction. If he be emmetropic, his distant vision
continues good, while his vision for near work is much impeded. If
he be hypermetropic, as he requires his accommodation for distant
objects, vision for distance is interfered with, and still more so, vision

4()4 DISEASES OF THE EYE. [chap. xvr.

for near objects. If he be myopic, vision is less affected than in
either of the other forms of refraction ; indeed, if he have more than
4 D of M, being thereby enabled to see near objects at his far point,
he may sufl'er little or no inconvenience.

Micropsia is a common symptom in cases of incomplete paralysis
of accommodation, and is due to the fact that, while the retinal image
is unaltered in size, the greater effort of accommodation required
gives the sensation of the object being much nearer to the eye than
it really is.

Causes. — Paralysis of accommodation may be caused by poisons
acting locally (atropine) or through the system (ptomaines, nicotine,
lead) ; but it is also the result of, or is attendant upon, various
diseases. It is one of the symptoms of paralysis of the third nerve ;
it may be due to rheumatism or to exposure to cold ; or it may
depend upon syphilis, syphilitic periostitis at the sphenoidal fissure,
syphilitic gumma, or syphilitic inflammation of the nerve itself.

Double paralysis of accommodation is often nuclear. Paralysis
of accommodation and mydriasis are sometimes forerunners by many
years of serious mental derangement.

Diphtheria is a frequent cause of paralysis of accommodation,
usually without, but sometimes with, mydriasis. The onset occurs
most commonly some weeks after the throat affection, which need
not have been of a severe character. Indeed, the faucial attack
may have had no apparent diphtheritic character, and may have
been so slight as almost to have escaped the notice of the patient,
although sometimes albumen will be found in the urine, the speech
may be somewhat nasal in character, and the patellar reflexes de-
fective. The lesion in these cases is probably a nuclear one, and the
evidence points to miliary extravasations of blood in the lloor of
the fourth ventricle ; but some hold that the paralysis is due to
a poison, that it is a toxic paralysis.

In influenza, paralysis of accommodation is seen, occurring some-
times in the acute stage and sometimes during convalescence. One
recorded case went on to bulbar paralysis, and ended fatally ; but
complete recovery is usual.

Paralysis of accommodation in middle life may be due to diabetes,
and should raise the suspicion of the presence of this disease. It
may also occur in chronic alcoholism and in diseases of the spinal
cord — e.g. locomotor ataxy.

CKAV. xvi.l ANOMALIES OF ACCOMMODATION. 405

Blows on the eye are apt to cause paralysis of accommodation,
usually with mydriasis.

The Treatmrnt depends, of course, upon the cause of the paralysis.
The instilhition of a. 1 per cent, solution of sulphate of eserine or of
muriate of pilocarpine may be employed in all cases, and will at
least produce temporary improvement of sight ; but it can hardly
be said to assist in the cure, except perhaps in slight diphtherial cases.
Iodide of potassium and mercury are indicated in syphilitic cases,
and iodide of pota&sium and salicylate of sodium in rheumatic cases.
The prognosis in these cases must be very guarded, as it often
happens that recovery does not take place. No further symptoms
may occur, but in some instances it may be followed by external
ophthalmoplegia. Where cure does not result the patient may be
enabled to make better use of his eye or eyes by means of a convex
glass or spectacles ; but in this matter each case must be dealt
with for itself — no general rule can be laid down.

In diphtherial cases a general tonic treatment, especially iron, is
indicated ; and here the prognosis is invariably favourable.

Accommodative Asthenopia

has been already treated of under the head of Hypermetropia
(p. 434).

Spasm of Accommodation.

Spasm, or cramp, of accommodation in connection with hyper-
metropia and myopia has already been referred to. A few cases of
acute spasm of accommodation have been reported. Occurring in
an emmetropic or slightly hypermetropic eye, such a spasm produces
apparent myopia. In some of the cases there was no assignable
cause for the spasm, in some it was due to overwork, and in one to
trauma of the cornea. The treatment is a lengthened course of
atropine locally.

CHAPTER XVII.

THE ORBITAL MUSCLES AND THEIR
DERANGEMENTS.

Normal Action of the Orbital Muscles.

The eyeball, which is held in position by the orbital fascia and
capsule of Tenon with its orbital prolongations, is moved round a
point on its antero-posterior axis, situated (in the emmetropic eye)
1-4 mm. behind the cornea, and 10 mm. in front of the posterior
surface of the sclerotic. Its motions are affected by means of the
six orbital muscles, arranged in three pairs, each pair consisting of
two antagonistic muscles ; thus the rectus internus and rectus
externus are antagonists, the former rotating the eye inwards, and
the latter rotating it outwards. The remaining pairs are the recti
superior and inferior, and the obliqui superior and inferior.

The Primary Position of the Eyeball is that one in which, the
head being held erect, the gaze is directed straight forwards in the
horizontal plane. This is the starting-point from which the actions
of the muscles are considered. In this position the visual axes
are parallel.

The Rectus Externus and Pectus Internus, lying from their origin
to their insertion in a plane which corresponds with that of the hori-
zontal plane of the eyeball, move the latter on its perpendicular
axis directly inwards and outwards, and have no other action.

The Superior and Ijiferior Recti arise at the back of the orbit to
the inner side of the eye, and pass forwards and outwards. There-
fore the plane of these muscles does not correspond with the antero-
posterior vertical plane of the eyeball, but passes from within and
behind, forwards and outwards. Consequently their axis of rotation,
though lying in the horizontal plane, is not the horizontal axis of
the eyeball, but one which, passing from within and before, back-

466

CHAP. xvrr.

THE ORBITAL MUSCLES.

467

wards and outwards, forms with
the antero-posterior axis an angle
of 70° (Fig. 186). Being inserted
in front of the centre of rotation,
their action is mainly to rotate the
eyeball upwards and downwards,
but, coming from the inner side,
they also rotate it somewhat in-
wards. Moreover, the superior
rectus gives to the vertical meri-
dian of the cornea an inward

inclination.

or inwar(

^heel-

motion, or torsion of the eye {vide
infra), while the inferior rectus

gives this meridian an outward .inclination, or outward wheel-
motion of the eye. The power of these muscles over the upward
and downward motions is greatest when the eye is turned out, for
then their axis of rotation coincides most closely with the hori-
zontal axis of the globe ; and their influence over the wheel-
motion is greatest when the eye is turned in, for then their axis
of rotation coincides most closely with the antero-posterior axis

of the globe.

The plane of the Oblique Muscles
of the eyeball also approaches the
antero-posterior vertical plane of
the eyeball, the axis upon which
they rotate the latter passing from
within and behind, forwards and
outwards, and making with the
antero-posterior axis an angle of
35° (Fig. 187). The principal ac-
tion, accordingly, of the oblique
muscles is to incline the vertical
meridian of the cornea ; the superior

Fig. 187.— Left Eye.

1 In speaking of the inclination of the vertical meridian of the cornea
it is the upper extremity of this meridian which is meant. Inward means
toward the nose or median plane of the head, and outward towards the
temple. These wheel-motions are sometimes designated by the terms
intorsion and extorsion.

4()8 DISEASES OF THE EYE. [ohap. xvti.

oblique inclines it inwards (wheel-motion inwards), the inferior
oblique inclines it outwards (wheel-motion outwards). In addition
to this, since the fixed })oinl fioni which they act is at the front of
the inner side of the orbit, and since they are inserted behind the
centre of rotation, they will each of them rotate the eyeball out-
wards. Moreover, the superior oblique will move the eye down-
wards, and the inferior oblique will move it upwards. It is evident
(Fig. 187) that the power of the oblique muscles over the upward
and downward motions of the eyeball is greatest when the eye is
turned in, and that their power over the wheel-motion is greatest
when the eye is turned out.

To sum up then : Vertical motion. — The recti move the eye in
the direction indicated by their names, the superior upwards and
the inferior downwards. The obliques move the eye in the opposite
direction to their names, the superior oblique moving it downwards,
and the inferior oblique upwards.

Horizontal motion. — The recti move the eye inwards, the obliques
move it outwards.

Wheel-motion (torsion). — The superior (rectus and oblique)
muscles rotate the vertical meridian inwards ; the inferior (rectus
and oblique) muscles rotate the vertical meridian outwards. The
action of the obliques on the wheel-motion is greatest when th« eye
is rotated outwards, and of the recti when the eye is rotated inwards.

It may also be noted that the obliques acting together would
move the eye directly outwards, the other actions of these muscles
neutralising each other ; similarly the superior and inferior recti
acting together would rotate the eye directly inwards. But simul-
taneous action of these several pairs of muscles does not occur under
normal conditions.

1 . In the Primary Position all the muscles are at rest.

2. Motion of the eyeball directly outwards is affected by the ex-
ternal rectus alone, and motion directly inivards by the internal
rectus alone.

3. Motion of the eyeball directly upivards and directly downwards
is effected chiefly by aid of the superior and inferior recti. . But
these muscles acting alone rotate the eye slightly inwards, and tilt
the vertical meridian, which in this position should be upright.
The assistance of the obliques is therefore necessary to counteract
these subsidiaiy effects. For example, the superior rectus moves

CHAP. XVIT.

THE ORBITAL MUSCLES.

469

the eye upwards and inwards, and inclines the vertical meridian
inwards ; the inferior oblique moves it also upwards, but at the same
time turns it outwards, and inclines the vertical meridian outwards,
so that when the two muscles act together, the second and third
effects mentioned neutralise each other, and the result is a vertical
motion upwards. Similarly, the inferior rectus requires the assis-
tance of the superior oblique.

In oblique positions of the eyes, the vertical meridian no longer
remains vertical but becomes tilted, as shown in Fig. 188 (compare
with Fig. 193).

4. Rotation ujnvards and outwards is effected by the superior

Left Eye

Right Eye

Torsion due to
OttUque Miisrle:

Torswn due to
Vertical Recti Muscles

Torsion due to
Oblique Muscles

Fig. 188. — Illustrates the torsion of the vertical meridian in
oblique positions of the eyes. In motions of both eyes the meridians
are inclined in the same manner, as at 2 and 2', 3 and 3' and so on.
Compare this with Fig. 193.

rectus, inferior oblique, and external rectus ; but since in an out-
ward position of the eyeball the torsion effect of the obliques is at
its greatest, while that of the recti is diminished or nil, the action
of the inferior oblique in this respect will preponderate, and the
vertical meridian will therefore be inclined outwards (2' or 4, Fig. 188).

5. Rotation downivards and outivards is due to the action of the
inferior rectus, superior oblique, and external rectus, and here also
the torsion effect of the oblique muscle will prevail, and the vertical
meridian w^ill be inclined inwards. (3' or 5, Fig. 188.)

6. Upward and inward rotation is produced by the superior
rectus, inferior oblique and internal rectus. l)iit in tlie inward position

470 DISEASES OF THE EYE. [chap. xvii.

of the eyes the torsion efiect due to the rectus will prevail over that
due to the inferior oblique, and the vertical meridian will thus be
inclined inivards. (4' and 2, Fig. 188.)

7. In rotation downwards and inwards the inferior rectus, superior
oblique, and internal rectus act together ; and, for the reason just
mentioned, the vertical meridian will be inclined outwards by the
inferior rectus. (5' and 3, Fig. 188.)

The movements of each eye have been considered, so far, as
taking place separately, but in reality the eyes move together, their
movements being associated. Parallel movements of the eyes in
various directions are called conjugate, while inward rotation of the
eyes, for the purpose of fixation of near objects, is known as con-
vergence. Conjugate movements may also take place combined
with convergence.

Movement of the eyes upwards is generally accompanied by
slight divergence, and movement downwards by slight convergence,
owing to the closer proximity of objects to the eyes below the hori-
zontal plane, and their greater distance from the eyes when above
that plane.

* In conjugate movements of the eyes into oblique positions,
even with parallel visual axes, a symmetrical wheel-motion, or
torsion, occurs, as shown in Fig. 188. In the primary position
(P. and P^), and also when the eyes are turned directly to the right,
to the left, upwards, or downwards, the vertical meridians of the
corneas (as indicated by the lines passing through the pupils), main-
tain their vertical direction. In other positions this meridian
becomes tilted to one or other side, but in the same direction for
each eye. For example, on looking to the left and upwards the
inclination of the vertical meridian is to the left in both eyes (Fig. 188,
2' and 2). The effect of motion in the three other oblique positions
is also shown. The explanation of this torsion has already been
given when the movements of the eyes separately were discussed.^

* The muscles which act together in conjugate movements are
said to be associates. The right internal rectus, for example, is

1 This effect is often called " false torsion," because it is not directly
duo to the twisting of the eye on its antero-posterior axis, but to the fact
that the rotation iuto the oblique position is accomplished by movement
of the eye on an oblique axis, which lies in the equatorial plane (Listing's
plane) of the eyeball.

CHAP. XVII.] THE ORBITAL MUSCLES. 471

the associate of the left external rectus, in movements of both eyes
to the left. In the vertical movements directly upwards and down-
wards, the two muscles engaged in one eye are associated with the
corresponding two muscles in the other eye ; }3ut, in the oblique
positions, the muscles which are mainly associated in their action
are those of which the names are opposed in every way. For ex-
ample, in looking to the left and upwards (in addition to the lateral
recti) the real associates are the left suferior rectus and the right
inferior oblique ; because, in this position, the axis of the left eye
lies in the plane of the recti muscles, while the axis of the right eye
lies in the plane of the oblique muscles.

Conjugate motions and movements of convergence are the only
motions of the eyes which can be accomplished voluntarily. Diver-
gence of the eyes is not possible under normal conditions — it would
be useless for binocular vision. Torsion, or rotation round an
antero-posterior axis, which has been described above, occurs, within
limits, on inclining the head, the object being to keep the vertical
meridian vertical. Very slight torsion occurs on convergence also.
But these latter actions of the muscles are all involuntary.

* Objective and Subjective Localisation, or Orientation.— An
image of the field of vision is formed on the retina, and the image
of each object in the field is ' projected ' outward along the secon-
dary axis passing through the nodal point, or optical centre of the
eye, to its proper position in the field. This relation of objects to
one another in space is called objective localisation.

Subjective localisation consists in the appreciation of the position
of the body and of the eyes in relation to external objects, and is
gained chiefly through the sense of muscular effort necessary to
bring the eyes into position for the fixation of those surrounding
objects. Hence arises the false judgment of position and the re-
sulting giddiness, caused by sudden loss of power in the orbital
muscles.

* The Field of Fixation. — The field of fixation, which shows the
range of mobility of the eyeball, contains all points that the eye
can successively see or ' fix ' with the macula lutea, without move-
ment of the head. It can be measured with the perimeter, as in
testing the field of vision, except that here the patient is made to
move the eye as far as possible in each meridian, and the limit of
each movement is measured by observing the corneal reflex of a

472 DISEASES OF THE EYE. [chap. xvii.

candle flame, or oplithalmoscope mirror, which is moved along the
arc of the perimeter. The binocular field of fixation contains all
points which can be seen as single with the two eyes and without
movement of the head. The averages give, for movement of one
eye, inwards 44°, outwards 46°, upwards 44°, and downwards 50°.

Strabismus.

When looking at any object with both eyes it is necessary, in
order to avoid seeing double, that the visual axis of the eyes should
meet at the point fixed. When this does not take place, one of the
eyes must be in a faulty position, or, as it is commonly termed, it
squints. This condition is called Strabismus, and may arise either
from over-action or from paralysis of one of the muscles. Strabis-
mus may occur in any direction, but vertical and oblique deviations
are less common than the convergent or divergent forms.

In order to ascertain, in slight cases, which of the two is the
deviating eye, the patient is made to fix an object, and one eye, say
the left, is rapidly covered with the surgeon's hand ; then, if the
right eye, which is not covered, make no movement, it must have
been looking at the object before the left one was covered ; but if
now, on covering the right eye, the left make a movement in
order to fix the object, then this eye must be the squinting one.
The movement is always in the opposite direction to the devia-
tion. For instance, if the eye be turned inwards too much, it must
of course turn outwards to fix the object, when its fellow is covered.
Another good method consists in observing the position of the
corneal reflex when the patient looks at the ophthalmoscope (see
Measurement of Strabismus). But the most delicate test is the
character of the diplopia, if diplopia be present.

Apparent Strabismus is due to a large angle y (p. 3). In this
case, as the visual axes are both directed to the point fixed, there
w^ill be no movement of either eye on covering the other, as in true
strabismus.

Real Strabismus may be Paralytic, Concomitant, or Latent.

* Latent Strabismus, also called Muscular Insufficiency or
Heterophoria. — In these cases strabismus only occurs in exceptional
conditions, such as the use of tests which interfere with, or render
more difficult, binocular vision. Under the usual conditions,

CHAP. XVII.] THE ORBITAL MUSCLES. 473

binocular vision is maintained in these cases, but this involves a
muscular effort greater than normal, and hence these patients suffer
from muscular asthenopia.

Binocular Vision. Sense of Fusion.— When an object is looked
at, the visual axes meet at that object or point of fixation [binocular
fixation), and the two retinal images are fused into one by a cerebral
process, so that the object appears single. This constitutes binocular
single vision. All objects situated about the same distance from the
eyes and in that portion of the field which is common to both, form
images on corresponding parts of the retina?, and they too are per-
ceived as single. The slight differences in the images of an object
as seen from the point of view of each eye generate the perception
of relief or stereoscopic vision, which is the highest grade of binocular
vision. The fusion sense — i.e. the mental desire for single vision —
develops in infancy, but in different individuals it exists in different
degrees. Binocular fixation may, for instance, be present without
true fusion, only one of the images being perceived, while the other
is suppressed ; as is proved by the inability sometimes to produce
double vision by means of a prism. Not only this, but the sense
of fusion is more easily disturbed in some persons than in others,
when binocular vision is rendered difficult by artificial means.

The existence or otherwise of true binocular vision may be ascer-
tained by the simple experiment of giving the patient a book to
read, and then holding a cedar pencil halfway between his eyes and
the page, at right angles to the lines of type. If binocular vision
be present, the pencil will not offer any impediment to the reading ;
but, if it be not present, parts of the page will be hidden behind the
pencil. The reader may prove this by performing the experiment on
himself, first with both eyes open (binocular vision), and then with
one eye shut.

Another method is that known as Bering's Drop Experiment.
A hollow cylinder about 25 cm. long, and wide enough to take in both
eyes of a person, is provided — at the opposite end from that placed
around the eyes — with two strong wires 18 inches long, which jut
out in continuation, as it were, of the cyhnder, but which are bent
outwards sufficiently to keep them out of the view of the patient.
Between the ends of these wires a fine thread is stretched, with a
small bead fastened at its middle point, so that the bead may occupy
the centre of the field when the patient looks through the cylinder.

474 DISEASES OF THE EYE. [chap. xvii.

During the experiment the thread is in the horizontal position, and
the bead is used as the patient's fixation point. Small balls of
different sizes (peas, beans, etc.) are then let fall from a height, one
after another, a couple of dozen times or more, some of them in front
of the tliread, some of them behind it. If the patient have normal
binocular vision, he will be able to say each time with certainty
whether the ball falls in front of, or behind the thread ; but if he
have not true binocular vision, if only one eye be used, he will merely
guess at the position of the falling ball, and will make frequent
mistakes.

Binocular Vision can also be tested by the stereoscope in its
various forms, or by the amblyoscope, the diploscope, or diaphragm
test.

Diplopia, or double vision, always occurs in the absence of bin-
ocular fixation — i.e. when strabismus is present — provided binocular
vision had previously existed. One image is seen by each eye, and
the double vision disappears on closing one eye. This is binocular
diplopia, as distinguished from monocular diplopia, in which two
images are formed on the retina of one eye, as the result of irregular
refraction (incipient cataract, dislocated lens, irregular astigmatism,
double pupil).

The image seen by the eye which looks at, or fixes, the object
is called the ' true image.' That which corresponds with the de-
viated eye is the ' false image ' ; and, as it does not lie on the macula
lutea, it appears less distinct than the former. The false image
always appears to the patient to be, or is ' projected ' by him, in
the opposite direction to the displacement of the eye, so that the
diplopia is the reverse of the position of the eyes.

When the image seen by the affected eye lies to the correspond-
ing side, the diplopia is termed homonymous. Homonymous double
vision therefore always indicates convergence of the visual lines.
Fig. 189 explains the occurrence of homonymous diplopia in con-
vergent paralytic strabismus.^ The right eye fixes the object o,
and its image falls on the macula lutea m ; but the left eye, by
reason of paralysis of the external rectus, is turned in, and its visual
axis lies in the direction m v, and the image of o falls to the inner

^ For the sake of simplicity in the diagram tlie effect which rotation
of__the eye has on the nodal point is omitted.

CHAP. XVII,]

THE ORBITAL MUSCLES.

475

side of the macula liitea at a. Now why should this image not be
referred to its correct position along the line a o ? The reason is
that the patient is not conscious of the deviation of this eye ; and,
having always been in the habit of superposing his fields of vision,
so that the visual axes of the eyes meet at the object fixed, he
imagines this to be still the case, and that v m lies in the position
of a, and that the macula lutea m is at m^ But if this were so,
a would be at a' , and in this position of the eye, images formed at
ci to the inner side of the macula lutea are projected to the outer

ni'] f a'

Left Eye. Right Eye.

Fig. 189.

side of the field, along the line a o\ and the patient imagines that
occupies the position o", as seen with the left eye.

If the left eye were deviated outwards, the image of o would fall
to the outside of the macula, and would therefore be projected to
the right of the true position of the object. The right image w^ould
then belong to the left eye and vice versa ; this is crossed diplopia,
and indicates divergence of the visual lines. A very simple experi-
ment will prove this : when a finger is held up in front of the eyes,
and a distant object is fixed, it will be noticed that the finger is seen
double ; if now the right eye be closed, the left image of the finger
will vanish. The diplopia here is crossed because the convergence
of the eyes is less than that required for fixing the finger — there is, in

470 DISEASES OF THE EYE. [chap. xvit.

fact, a relative divergence. If the finger be now fixed, a bright
object farther away will be seen double, but the diplopia will be
homonymous, because the eyes are convergent. This is a physiolo-
gical diplopia, to which we habitually pay no attention, and as
the images are formed on parts of the retina other than the macula
lutea, we are not disturbed by its existence, although it uncon-
sciously enables us to locate the position of objects as being nearer
or farther than the object fixed.

When an eye is deviated upwards or downwards, the correspond-
ing image is projected downwards or upwards ; and torsion of the
vertical meridian in one direction produces a tilting of the image in
the opposite direction.

For the effect of prisms on the production and correction of
diplopia, see chap. xv. § 9.

It is necessary that the foregoing shall have been clearly under-
stood, before the study of paralysis of the orbital muscles is
approached.

Paralyses of the Orbital Muscles.

We shall now consider the symptoms produced by paralysis of
the orbital muscles without regard to the nature or seat of the
causative lesion. These symptoms may be general, that is to say,
common to all the muscles, or special — that is to say, dependent
on the particular muscle affected.

General Symptoms.— (1) Strabismus due to the action of the
opponent muscle. This is called the primary deviation. (2) Loss
or diminution of movement in the direction of normal action of the
affected muscles. (3) Diplopia, due to the strabismus ; or, if the
paralysis be but slight, actual diplopia may not be present, but the
double images overlapping each other will cause dimness or con-
fusion of sight. (4) Giddiness and uncertain gait, due partly to the
diplopia, and partly to faulty projection of the object. (5) False
projection, by which is meant the false conception of the position of
the image in the field of fixation. It causes difficulty in walking and
working, and is most noticeable when a depressor muscle is affected.
(6) Some patients turn the head towards the side of the paralysed
muscle, in order to diminish or eliminate the diplopia — e.g. if the
left ext. rectus were paralysed, the head would ])e tui-ned towards

CHAr. xviT.] THE ORBITAL MUSCLES. 477

the left ; if it were the left int. rectus, the head would be turned
towards the right. By this manoeuvre the loss of the action of the
affected muscle is less felt for those objects which lie straight in the
patient's path, while he walks about ; because it involves a rotation
of the eye towards the side of the healthy antagonist, in which
region of the binocular fixation field the diplopia is reduced to a
minimum. Some patients close one eye, usually the affected one,
to procure single vision. It will be noted that 1,2, and 6 are objective
symptoms, while 3, 4, and 5 are subjective.

In peripheral paralysis it is most common to find only the muscle,
or muscles, supplied by some one nerve — the third, fourth, or sixth
— affected ; although, of course, exceptions to this are not rare,
especially where a neoplasm forms at the base of the skull.

In studying a case of paralysis of an orbital muscle the following
. General Principles should be borne in mind : — (1) The defective
mobility and the diplopia increase towards the side of the affected
muscle — towards the left, if the left external rectus be paralysed ;
towards the right, if the left internal rectus be paralysed. The image
which is farthest in the direction in which the diplopia increases
belongs to the paralysed eye. (2) The secondary deviation {i.e. the
deviation of the sound eye while the affected eye fixes) is greater
than the primary deviation ; because the muscle in the sound eye,
which is associated in its action with the paralysed muscle in the
affected eye (e.g. the rect. int. with the rect. ext.), must receive a
nervous impulse of equal intensity to that sent to the weak muscle,
and, as the latter requires a considerable impulse to excite its action,
its associate will be over-excited. Let us suppose the left external
rectus to be paralysed, and that, shading the right eye with a hand,
we direct the patient to fix with his left eye an object held somewhat
to his left side ; we may notice, on removing the shading hand, that
the right eye has been rotated inwards to an extent far exceeding
that of the primary deviation of the left eye, and has now to make
an outward motion in order again to fix the object. (3) The image
formed on the retina of the affected eye is projected {i.e. seems to
the patient to lie) in the direction of the paralysed muscle ; in other
words, the position of the false image corresponds with the normal
action of the paralysed muscle, because the deviation of the eye
is in the opposite direction to the action of the paralysed muscle —
e.g. if the left ext. rect. be paralysed, the image corresponding with

478 DISEASES OF THE EYE. [chap. xvti.

that eye will be projected to the left of the image belonging to the
right eye. (8ee Diplopia, p. 474.) When the affected eye fixes alone,
the faulty projection is twice as great as when fixation is binocular.
(See General Principle, No. 2.)

The deviation of the eye, the strabismus, alone is in the opposite
direction to the paralysed muscle ; all the other signs, defective
mobility, false projection, increase of diplopia, secondary deviation,
and position of the head, are towards the paralysed muscle.

The Special Symptoms due to paralysis of individual muscles
will now be considered.

Paralysis of the External Rectus of the Left Eye.— If this be
complete or considerable, it is easy of diagnosis for along with con-
vergent strabismus there is marked loss of power and motion of the
left eyeball outwards, and the patient complains of double vision.
He keeps his head turned to the left, in order to diminish the in-
fluence of the paralysed muscle as much as possible.

If, however, the paralysis be but slight, the patient may not com-
plain decidedly of diplopia, but only of indistinctness or confusion
of sight, especially when he looks towards the left. To decide the
diagnosis in such a case, the double images must be examined. A
long lighted candle is used as the object to be looked at ; and one
eye — let us say here the left eye — is covered with a bit of red-stained
glass in order to differentiate the images.^ The candle is now held
on a level with the patient's eyes, and straight opposite him,
about three metres' distance (eyes in primary position), (a) In this
position the images are seen very close together or overlapping each
other, both of them upright and oh the same level, the red candle to
the left, the white to the right — i.e. homonymous diplopia = con-
vergence. This convergence must be due to paralysis of one or
other external rectus muscle, but we cannot say at this stage of the
experiment which of them is affected. (6) In order to determine
this point, the candle must be carried from side to side, and the in-
creasing or decreasing distance of the images from each other noted.
If the candle be carried slowly to the right, the patient following it
with his eyes without turning his head, the images come closer
together, or only one candle is seen. But if the candle be carried to

* Maddox's Rod Test, described farther on, is very suitable here, and
in the investigation of other forms of ocular palsy.

CHAP. XVII.] THE ^ORBITAL MUSCLES. 470

the patient's left, the images go farther apart, their relative posi-
tions being maintained. We now know that it is the left external
rectus which is affected : because towards the left — the direction in
which the action of this muscle is most wanted, and consequently its
loss most felt — the distance between the double images increases.
The images are erect, as no wheel-motion is caused by action of the
external rectus. (c) If, liowever, the candle be held to the left and
raised aloft, the image belonging to the left eye will seem to lean
away from, and to be a little lower than, that of the right eye (Fig.
190). The reason of this is that, owing to the paralysis of the external
rectus, the left eye cannot look sufficiently outwards, but merely
looks upwards. The inferior oblique loses some of its torsional
power, but retains a greater power of elevation. The left eye there-
fore is higher than the right, and its vertical meridian remains
vertical. But the right eye, which is free to
follow the candle, looks up and to the left. Its ^ ^]

vertical meridian is therefore inclined to the
left. That is, the vertical meridians of the
two eyes converge at the top, which necessitates
a divergence of the upper extremities of the
images. The rotation of the right eye in this
position is physiological, and its image is there- -^^^ ^QO

fore judged to be vertical ; while the image
of the left eye diverging from that of the right, though really
vertical, is judged to be oblique. An analogous displacement of
the eye downwards, and defective rotation of the vertical meridian
due to the superior oblique, takes place in the position below and to
the outside, (d) If the patient be told to direct his gaze specially to-
wards the red candle — i.e. the image which belongs to the left, the
affected, eye — the distance between the two candles will be much
greater than if he direct his gaze towards the white candle. This is
explained by ^General Principle No. 2 (p. 477).

• If the patient's good eye be closed, and an object (surgeon's
finger) be held up within his reach, but towards his left side, and he
be requested to aim rapidly at it with his forefinger, he will aim to
the left of it. The nervous impulse sent to his left external rectus,
to enable him to turn the eye towards the object, is of such intensity
as to lead him to fancy that the object lies much farther to the left
than is the case (incorrect projection of the field of view) ; for we, to

480 DISEASES OF THE EYE. [ru.w. xvn.

a great extent, estimate the distance of objects from each other by
the amount of nervous impulse supplied to our orbital muscles in
motions of the eyeball.

A prism held horizontally before the atl'ected eye with its base
outwards brings the double images closer together ; or, if the correct
prism be selected, the iin;iges will he blended into one.

* Paralysis of the Superior Oblique of the Left Eye.— This
paralysis will be most apparent when a demand is made for motion
of the eyeball downwards and inwards, the action of the superior
oblique as a depressor being greatest in this position. Yet absolute
defect of motion is sometimes difficult to detect, even in complete
paralysis of this muscle, owing to vicarious action of the inferior
rectus and of the internal rectus. Careful examination of the secon-
dary deviation will often be successful as to this point. But it is
on the examination of the double images that we must chiefly rely
for the diagnosis, as follows : —

(a) In the whole of the field of vision above the horizontal plane
there is single vision. Below the horizontal plane in the median line
diplopia appears, the image belonging to the left eye standing lower
than that belonging to the right : because the superior oblique being
a muscle which assists in rotating the eye downwards, the latter, for
want of the action of this muscle, now stands higher than its fellow
(right eye). The position downwards and inwards of the eyeballs is
that in which the greatest demand is made upon the superior oblique
for rotation of the eye downwards : therefore it is in this position
its want for this purpose is most felt ; and wdien the candle is held
in this position, the vertical distance between the double images is
greatest, (h) The superior oblique assists also in rotation of the
eye outwards : therefore loss of its power must commit the eyeball
to a certain extent to the power of the muscles which move it inwards,
and a rotation in this latter direction (convergence) takes place, with
the result of making the image belonging to the left eye stand to the
left of the image belonging to the right eye (homonymous diplopia),
(c) The superior oblique inclines the vertical meridian inwards :
therefore, in rotation directly downwards, loss of its power commits
the eye to the outward wheel-motion imparted to it by the inferior
rectus. This gives to the image belonging to the left eye an inclina-
tion to the patient's right hand, (d) The power of the superior
oblique to incline the vertical meridian inwards is greatest when the

CHAP. XVII.] THE ORBITAL MUSCLES. 481

eye is turned downwards and outw^ards : consequently, in this
respect its paralysis will be felt chiefly in this position, and therefore
here the inclination of its image to that of the sound eye will be most
marked, (e) A remarkable phenomenon usually noticed in this
paralysis (and sometimes in paralysis of the inferior rectus) is that
the image belonging to the affected eye seems to stand nearer the
patient than that of the sound eye. This, it is believed, is due to
the fact that the lower image is projected on a plane nearer to the
patient, say where it appears to meet the floor.

To sum up, then (Fig. 191) : below the horizontal plane there
is homonymous diplopia, while the image (^4) of the affected eye
stands on a lower level, is inclined tow^ards the other image, and
seems to be nearer the patient. Furthermore : —

(/) In an extreme lower and outer position the image of the
affected eye may sometimes seem to
stand higher than that of the sound
eye, owing to an excessive outward
inclination of the vertical meridian,
which throws the image on the lower
and inner quadrant of the retina.

In order to do away with or to
diminish the diplopia, the patient ^y^ A
inclines his head forwards and towards
the right shoulder, and turns his face ^^^- 1^^-

towards the side of the good eye.

For the prismatic correction of the diplopia, two prisms will be
required ; one with its base downwards in front of the left eye, to
correct the vertical difference, and a second with its base outwards
in front of the right eye, to correct the lateral difference, or it may
be possible to correct it by a single prism in an oblique position.

Paralysis of the Third Nerve (Internal Rectus, Superior Rectus,
Inferior Rectus, Inferior Oblique, and Levator Palpebrae).— Com-
plete paralysis of all the branches of the third nerve produces a
remarkable appearance. The upper lid droops (ptosis), the eyebrow
is raised — from compensatory action of the occipito-frontalis — the
pupil is semi-dilated and immovable, the power of accommodation
is destroyed, and the eyeball is often slightly protruded, owing to
the backward traction of the recti being wanting. There is divergent
strabismus. Motion inwards exists but to a slight degree, and motion
31

482

DISEASES OF THE EYE.

[chap. XVI

downwards and outwards is effected only by aid of the superior
oblique, and is accompanied by marked inward wheel-motion, which
can be detected best by noting the change in position of a con-
junctival vessel. If the paralysis be of some little standing, the
external rectus obtains rule over the eyeball, and rotates it perma-
nently outwards.

The diagnosis, in cases of complete paralysis of all branches of
the nerve, is easily made ; but not so sometimes, if the paralysis be
only slight, and here the examination of the double images is of
value, as follows : —

If (Fig. 192) the left third nerve be partially paralysed in all

Fig. 192.

or most of its branches, there will be crossed diplopia either in the
whole of the field of vision — for want of power in the internal rectus
— or towards the patient's right at the least, and the lateral distance
between the images will increase as the visual object is carried
farther towards the right. When the visual object is held aloft the
left eye will not follow it — for want of the action of the two muscles
which turn the eye upwards — and, consequently, in this position its
image will stand, not only to the right of but also above that of the
right eye ; while, when the visual object is held below the horizontal
plane, the eye will — owing to paralysis of the inferior rectus — remain
higher than the right eye, and consequently its image will appear to
be lower than that of the right eye. It will, moreover, be inclined
towards the latter image, in consequence of the inward wheel-motion
imparted to the eye by the healthy superior oblique.

CHAP. XVII.

THE ORBITAL MUSCLES.

483

AVlien some branches of the third nerve are paralysed in each eye,
the diagnosis is often extremely complicated. The ptosis, however,
which is nearly always present, and is readily recognised, and the
paralysis of the sphincter iridis (mydriasis) and of accommodation,
which often exist, and are also easily observed, give valuable aid.
Moreover, any loss of motion upwards must be due to paralysis of the
third nerve ; but if there be loss of motion downwards, the differ-
ential diagnosis between paralysis of the inferior rectus (3rd Nerve)
and of the superior oblique (4th Nerve) has to be made. For this
see the paragraph on paralysis of the latter muscle.

As may be imagined from the foregoing, it is often difficult in
practice to keep clearly before one's mind the different actions of
the orbital muscles, and from the character of the diplopia to deduce
the paralysis which may be present. The mnemonic diagram
here given (Fig. 193) will assist in this respect, and it will serve also
as a control in reasoning on this subject.

The larger circles in Fig. 193 indicate the position of the cornea
resulting from the action of the elevator and depressor muscles of
the eye ; the smaller central circles represent the pupils. R and R

Oblique Muscles Recti Muscles

LIO

LS.R

L.S.O.

LIR

RSR

Oblique MiiscUs
RIO

T^x

RIR

RSO

Un Eye

Right Eye

Fig. 193. — Diagram illustrating the separate actions of the elevator
and depressor muscles. R.I.O. = Right Inferior Oblique, and so on.

represent the anterior extremities of the axes of rotation of the recti
muscles, which lie to the inner side of the cornea, and and
similarly the extremities of the axis of rotation of the obliques at
the outer side of the cornea. The dotted arcs of circles are those

484 DISEASES OF THE EYE. [chap. xvit.

described by the centre of the cornea in rotation of the eyes on these
axes. The two central arcs with their concavities tow^ards each
other represent the action of the recti muscles, and the two outer
arcs the action of the obliques. The vertical meridian of the cornea,
indicated by a line passing through its centre, is tangential to the
circles described by the centre of the cornea, and consequently,
when one muscle acts at a time, this meridian can be vertical only
in the primary position.

Now, to find the action of the right superior rectus, it is merely
necessary to look at the right superior quarter of the centre of the
figure (R.S.R.) and it will be seen at once that this muscle moves the
eye inwards, upwards, and inclines the vertical meridian inwards.
In the same way the action of an oblique muscle w^ill be found in
the outer portion of the figure on its own side, but as the vertical
action of the obliques is in a direction opposite to that indicated
by their names, the superior oblique will be found below and the
inferior above. The action of the left inferior oblique is found in
the outer portion of the figure, on the left side, above (L.I.O.).

Many facts can at once be understood by reference to the figure :
for example, that the recti are inward rotators or adductors, and
the obliques outward rotators or abductors ; that the superior
muscles produce inward torsion (R.S.R., L.S.R., R.S.O., and L.8.O.),
and the inferior muscles outw^ard torsion (R.I.R., L.I.R., R.I.O.,
and L.I.O.) ; also, that the right superior rectus (R.8.R.) for instance,
is the true associate of the left inferior oblique (L.I.O.) , their action
corresponding in all three respects — namely, motion upward, to
the left, and torsion to left, and so on.^

Now, since the deviation of the eye is in the opposite direction
to the normal action of the paralysed muscle, and the projection
of the false image is the opposite of the position of the eye, it follow^s
that the false image must appear displaced in the direction of the

1 The action of the muscles is considered as if the observer were looking
at his own eyes from behind. This view is taken in order that this figure
may correspond with Fig. 194, illustrating the diplopia, in which also
the observer considers himself to be the patient. To be quite accurate
it should be remembered that as the cornea moves out of the primary
position, it comes to lie more and more behind the plane of the paper in
the figure. In fact the arcs of circles are seen sideways and therefore
appear elliptical. The idea of this figure was suggested by Landolt's
method of demonstrating the action of the muscles on a rubber ball.

CHAP. XVII.]

THE ORBITAL MUSCLES.

485

action of the muscle, therefore Fig. 194, illustrating the diplopia,
is practically the same as Fig. 193.

In Fig. 194 the form of diplopia which characterises paralysis
of each muscle is expressed by the position of the dotted candle
bearing the name of the muscle. The dotted lines represent the
false images belonging to the affected eye, the continuous lines the
true images belonging to the unaffected eye.

In the case of the recti, the false images enclose a lozenge-shaped
space in the centre of the figure, whereas the false images correspond-
ing with the obliques will be found in the outer portions. It will also
be noted that the dotted lines extend upwards and downwards be-
yond the others, indicating respectively that the false images are
higher or lower than the true ones. Another fact which the diagram

LIO

LS.R^RSR

RIO

OhUqae

LSO.

Rail

LIR X'rIR,

, Oblique

RSO

Left Eye RiglitEye

Fig. 194. — Diagram of the diplopia due to paralysis of any one
of the elevator or depressor muscles. ^

indicates is that, in the case of the muscles represented in the upper
halves of the figures, the diplopia occurs in the ufiper part of the
field of fixation, or, in other words, in upward movements of the
eyes. A similar rule holds good with regard to the lower halves.

The method of using the diagrams will be better understood by
taking a particular muscle as an example. Suppose, for instance.

1 Fig. 194 is a combination of two mnemonic diagrams which appeared
in previous editions of this book. They have been so combined in order
to correspond exactly with Fig. 193, ilhistrating the action of the muscles.
A comparison of Figs. 188, 193, and 194 will reveal that they are practically
the same, and that Fig. 1 93, which shows the action of the muscles, will
consequently also represent tlie diplopia characteristic of each muscle,
and also the torsion which occurs in extreme obliqvie positions. (L, W.)

486 DISEASES OF THE EYE. [chap. xvii.

that we wish to know what kind of diplopia results from paralysis
of the left inferior rectus, it is simply necessary to look at the left
inferior part of the centre of the figure (recti), which gives the dip-
lopia. If we analyse this we find (1) that the diplopia is crossed,
for the false image corresponding with the left eye is on the right of
the true image — i.e. the right image corresponds with the left eye ;
(2) that the false image has its wjoper end inclined towards the true
one ; (3) that the false image is lower than the true one, for the
dotted line extends lower than the other one ; (4) that the diplopia
occurs in downward movements of the eyes, for it is in the lower
half of the diagram that the false image lies.

The same method applies to the other recti ; the diplopia for
the right upper rectus is found in the right upper quadrant, and
so on for the rest.

The diplopia corresponding with one of the obliques will be found
in the outer part of the figure on the same side as the muscle, and
for the same reason as in Fig. 193 the superior oblique will be below
and vice versa. L.S.O. gives the diplopia for the left superior
oblique.

The figures can be called to mind either as consisting of the four
recti in the centre and the four obliques at the outsides, or as being
made up of an x for each eye, with the two recti on the inside
and the two obliques on the outside.

This is an extremely simple method. By bearing the figures
in mind it is possible to tell immediately what kind of diplopia
would result from paralysis of any one of these muscles, and con-
versely, given the diplopia, to determine to which muscle it is due.
Fig. 194 may be used alone, without reference to the action of the
muscles, when there is little time for thought.

* Some of the paralyses seem to resemble one another very
closely in the form of the diplopia produced ; for example, para-
lysis of the left superior oblique, and of the right inferior rectus,
in which the diplopia occurs in both cases below the horizontal
plane, and the false image is to the left of, and lower than, the
true one, and inclined towards it. The distinction is made by
observing that the false image belongs to the left eye (homonymous
diplopia) in the case of the oblique muscle, and to the right eye
crossed diplopia) in the case of the rectus. Figs. 195 and 196
explain this.

CHAP. XVII.]

THE ORBITAL MUSCLES.

487

Again, as Duane points out, the position of the eye in which
the vertical element of the diplopia is at its maximum is of the
greatest importance for the diagnosis of the muscle at fault, in the
case of the elevators and depressors. In the above cases, for instance,

.4^'

L // -

Fig. 195.

Fici. 196.

Fig. 195. — Paralysis of left sup. oblique. Homonymous diplopia,
R, image of right eye. L, image of left eye.

Fig. 196. — Paralysis of right inferior rectus. Crossed diplopia. R,
image of right eye. L, image of left eye.

the vertical separation of the images in paralysis of the left superior
oblique will be at its greatest when an attempt is made to turn the
eye downwards and inwards ; and the maximum deviation in this
respect, in the case of the left inferior rectus, will be found when the
eye looks downwards and outwards (p. 467).

In case the diplopia does not correspond with any of the recognised
forms characteristic of paralysis of any single muscle, the condition becomes
complicated, and the solution of the question as to which muscles are at
fault is frequently impossible, but there are two very simple causes through

^:>«

Fig. 197.

Fig. 198.

Fig. 199.

which the nature of the diplopia may be changed and which should be
mentioned. In the first place the patient may fix with the paralysed eye,
and when this occurs the image belonging to it will seem to him to be in
a correct position, and that of the other eye will be apparently displaced.

488 DISEASES OF THE EYE. [chap. xvii.

It is merely necessary to suppose that the diagram of the diplopia in the
particular case is rotated, so that the image belonging to the paralysed
eye becomes vertical. For example, Fig. 197 in this case would be
converted into Fig. 198.

Again, if paralysis of an elevator or depressor occurs in a patient
with a latent horizontal deviation, either convergence or divergence, a
crossed or homonymous diplopia may be reversed, on account of the
latent deviation becoming manifest in consequence of the impossibility
of fusing the images, and thus Fig. 197 would be changed to Fig. 198.

Measurement of the degree of paralysis is useful for prognosis,
and also for estimating the progress of the case. It may be measured
by noting the amount of separation of the double images. Mad-
dox's rod-test with scale is very suitable for this, or the prism required
to correct the diplopia may be noted, the deviation being equal to
half the angle of the prism. Another method consists in measuring
the mobility of the eye, in the direction of the paralysed muscle,
with the perimeter.

The Causes of Paralyses of Orbital Muscles.

Loss of power of one or more of the muscles of the eyeball is,
of course, always to be regarded as a symptom, not as a disease.

This loss of power may be due to lesions in several different situa-
tions, namely . — (1) Lesions situated in the orbit. (2) Basic lesions
— i.e. lesions situated at the sphenoidal fissure and those at the base
of the skull, between the sphenoidal fissure and the pons. (3) Pon-
tine lesions, which may be Fascicular — i.e. involving the ocular
nerve fibres in the substance of the pons — or Nuclear — i.e. only
attacking the nuclei of the nerves in the aqueduct of Sylvius and
floor of the fourth ventricle. (4) Cerebral lesions — i.e. supra-nuclear,
in the internal capsule, corona radiata, or cortex. These four
classes differ considerably in their clinical aspect, in their patho-
logical causes, and in their significance for the well-being of the
patient.

The first class — loss of power due to orbital lesions — will be
considered in the chapter on Diseases of the Orbit.

The second class — those due to basic lesions — provides by far
the largest number of cases of paralyses of the orbital muscles.
Basic paralyses are chiefly of rheumatic or syphilitic nature.

Rheumatic paralysis, to which the external rectus is specially
prone, will be noted if tliere be symptoms of general rheumatism, or

CHAP, xvii.] THE ORBITAL MUSCLES. 489

if there be a history of exposure to cold or wet immediately preceding
the attack. Some of these so-called rheumatic cases are probably
of toxic origin.

Syphilis will be suggested by a specific history, and rendered
certain by a positive Wasserman reaction. Peripheral paralyses of
the orbital muscles due to syphilis are amongst the later symptoms of
the disease, and may depend on exostoses or gummata at the base
of the skull, or to syphilitic neoplasms, or meningitis, in the course
of the nerve. The third nerve seems to be particularly liable to be
attacked by a solitary gumma at the base of the skull, especially at
the sphenoidal fissure, ptosis being commonly the first symptom.

Other causes are neoplastic growths, meningitis, purulent otitis,
aneurisms, etc. In arterio-venous aneurism in the cavernous
sinus, the sixth nerve is most frequently involved.

Fracture of the base of the skull may be indicated by a fourth
nerve paralysis, as the only symptom, due to injury of the nerve as
it passes over the apex of the petrous portion of the temporal bone,
but paralysis of the sixth nerve is more common with this lesion
and may be bilateral.

In the diagnosis of a basal lesion as the cause of the paralysis,
the gradual and successive involvement of different cranial nerves
according to their anatomical position, or even independently of
their anatomical arrangement, is suggestive ; as for example facial
neuralgia, or facial anaesthesia occurring along with paralysis of
ocular muscles. And the presence of atrophy of one or of both optic
nerves, or of a bi- temporal hemianopsia, would furnish conclusive
evidence of the basal origin of such paralysis.

Prognosis. — In peripheral paralyses recovery is very frequent,
much, however, depending on the nature of the lesion. In cases
where a cure is not effected, the diplopia eventually becomes less
troublesome and the antagonist muscle often contracted, the eye
being then rotated permanently and excessively in the corresponding
direction. In cases of old standing, a permanent contraction of the
muscles of the neck may be brought about, from the inclination of
the head which the diplopia has obliged the patient to adopt-

Treatment. — In these cases the medical treatment consists in
drugs suitable to the fundamental disease (rheumatism, syphilis,
etc.). Local depletion at the temple by the artificial leech in the
early stages, and galvanism later on, may be employed with advan-

400 DISEASES OF THE EYE. [chap. xvii.

tage. The most common method of applying galvanism is through
the closed lid ; but it is probable that the episcleral method — i.e.
with the electrode placed directly over the muscle — is more effectual.
A good method is for the surgeon to take one rheophore, well wetted,
in one hand, and, having secured good contact with the skin of the
palm, the index finger is applied to the patient's globe in the situa-
tion of the various external muscles of the eye. The finger is
covered with a single thickness of well -moistened muslin, and the
conjunctiva should be previously rendered insensitive by cocaine.
The other rheophore, a moistened plate, is placed on the nape of
the patient's neck. The strength of the current advised is from
1"5 to 2 milliamperes, and the alternate application and lifting of
the finger, by closing and opening the circuit, gives rise to a feeling
of a slight electric shock in the terminal point of the finger. The
operator should first test the strength of the current upon the
patient's cheek. The point of the finger thus employed acts as a
sentient rheophore, and can be applied with nicety and delicacy
to various parts of the eye, the operator being constantly aware,
by the feeling in his finger, of the strength of the current employed.

Passive orthoptic treatment occasionally gives a rapid and
brilliant result, while, again, it is useless. It is performed as follows :
— The conjunctiva at the corneo-scleral margin, near the insertion
of the paralysed muscle, is seized with a forceps, and the eyeball is
drawn in the direction of the muscle, and as far as possible beyond
its ordinary limit of contraction, and back again. These move-
ments are continued for about a minute once a day, cocaine
being used.

Prismatic glasses may be used, either to eliminate the diplopia,
or to excite the weak muscle to exert itself. In the former case, the
glass selected must completely neutralise the diplopia ; but, as it
can do so only for one position of the eyes, prisms are rarely employed
in this way. In the latter case, a prism slightly weaker than that
sufficient to completely neutralise the diplopia is selected, in order
that, with a little effort, the weak muscle may be enabled to bring
about single vision, and, this effort having been successfully main-
tained for some days, a still weaker prism is then prescribed, and so
on. Since more than a 4° prism in each eye can seldom be worn,
and the diplopia varies in different positions, the use of prisms here
is very limited.

CHAP. XVII.] THE ORBITAL MUSCLES. 491

It is important for the patient's comfort while awaiting his cure,
unless a cure by prisms as above described is being attempted, that
the affected eye should be covered, so that the distressing double
vision may be obviated ; or, better still, if it be a lateral muscle
that is paralysed, by excluding only the half of the field of the
defective eye in which diplopia occurs, it can take part in the act
of vision in the remaining half of the field.

Surgical treatment is justifiable only when, after six months or
a year, other means have failed to restore muscular equilibrium.
Advancement of the paralysed muscle with, if necessary, tenotomy
of the antagonist is indicated. Tenotomy of the associated muscle
of the other eye is sometimes performed to establish equilibrium, but
in this case a compensatory movement of the head must take place.
This surgical treatment applied to the internal and external rectus
sometimes gives satisfactory results ; but in the cases of the superior
and inferior recti it is less useful. The oblique muscles should not
be operated on, but tenotomy of the associated muscle in the opposite
eye (in the case of the K. sup. oblique, the L. inf. rectus) may give
relief.

A peculiar and rare form of peripheral or basal paralysis is Inter-
mitting Paralysis of the Third Nerve of one Eye, sometimes inaccurately
termed Ophthalmoplegic Migraine. The patients are generally children
or young adults, who usually svxffer, at long or short intervals, measured
it may be by months or years, from attacks of headache on the side corre-
sponding with the paralysed eye, and frequently from vomiting. This
' bilious attack ' is attended, or soon followed, by paralysis of one or
more branches of the third nerve. The paralysis may be complete or
partial, and the attack varies in its duration from a few days to a few
months. In rare instances the sixth nerve has been paralysed. Excessive
salivation, perspiration, or discharge from the nose occurs in a few cases.
Some cases are purely periodical — i.e. in the intervals between the
attacks of paralysis all the muscles supplied by the third nerve act in a
completely normal manner ; while in other cases these muscles, or some
of them, do not completely recover their functions in the intervals. There
are no visual symptoms such as occur in migraine, neither do the patients,
as in migraine, belong chiefly to the intellectual classes. We are as yet
quite in the dark as to the cause of these periodical paralyses of the third
nerve. It is possible that the purely periodical cases are of a functional
nature — reflex, or due to recurrent toxsemia, possibly of gastro-intestinal
origin — and that the periodically exacerbating cases alone are due to a
lesion of the root of the nerve, of an undefined kind, at the base of the
skull. In three cases of the latter kind, in which an autopsy was made,
there was disease of the trunk of the nerve at the base of the skull.

4!)2 DISEASES OF THE EYE. [chap. xvii.

In intermitting paralysis the Prognosis of the purely periodical form
is favourable, inasmuch as the attacks in the course of time become fewer
and less severe, until, finally, they entirely cease. In the exacerbating
form the prognosis for complete recovery is less favourable. Out of
twenty-six cases collected by Darquier only one patient died and from a
cerebral cause.

In view of the obscurity which still surrounds the causation of these
intermitting paralyses their Treatment must consist, in each case, in the
relief of any general dyscrasia or concomitant symptoms which may be
present. Purgatives and drinking of hot water have proved of some service
in some casps.

Paralysis of the Third Nerve with Cyclical Spasm. — This is also a
rare affection, the cause of which is unknown, but it may be described
here. In these cases there is partial paralysis of the third nerve, which
is usually congenital, and at intervals of about a minute the pupil contracts,
the upper lid becomes elevated and spasm of accommodation occurs,
associated, it may be, with convergence ; after a short interval of a few
seconds or a minute the paralytic condition again returns.

The third class of paralyses of orbital muscles above enumerated
— those due to lesions of the nuclei of the orbital muscles in the
aqueduct of Sylvius and floor of the fourth ventricle — are known by
the term

* Ophthalmoplegia Externa, and also as Nuclear Paralysis.— The
first of these terms was originally employed to denote those remark-
able cases in which all, or nearly all, of the orbital muscles of -both
eyes are paralysed, while the intra-ocular muscles often remain
intact. There can be no doubt, however, that these cases do not
differ in their nature from many of those in which, in one eye, several
orbital muscles supplied by different nerves — e.g. third and fourth —
are wholly or partially paralysed ; or where all the orbital muscles
in one eye are wholly or partially paralysed ; or where in each eye
muscles supplied by the same nerve — e.g. both sixth nerves — are
wholly or partially paralysed ; for such cases are often mild forms
of the disease, or else stages in its development. At one time it
was considered essential for the diagnosis, that the intra-ocular
muscles should retain their functions, but cases occur in which the
sphincter iridis and ciliary muscle are paralysed.

When the latter muscles alone are paralysed, the condition is
called Ophthalmoplegia Interna. AVhen both they and groups of
orbital muscles are paralysed the terms Ophthalmoplegia Interna et
Externa, or Ophtlialmoplegia I^niversa, are employed.

The term Nuclear Paralysis indicates any orbital paralysis due

CHAP. xviT.] THE nnniTAL MUSCLES^. 403

to a lesion of the nuclei of the orbital nerves in the pons, and ophthal-
moplegia externa often conies within this category.

Ptosis, even in cases of complete binocular ophthalmoplegia
externa, is often incomplete, and it is remarkable that in some
chronic cases, without any improvement in the condition itself, the
diplopia, which was at first present, quite disappears.

Occurrence and Progress. — The condition may be congenital, or
may make its appearance soon after birth, and may remain perma-
nently without becoming complicated with any further disturbance.
Congenital ptosis, which is frequently combined with loss of power
in the superior rectus, and is usually binocular, is of this nature. But
Nuclear Paralysis is more commonly seen as an acquired condition
in childhood, or in adult life, either in an acute or chronic form.
Marked cerebral lethargy is often seen with both forms, and the
tendon reflexes may be defective.

Acute Nuclear Paralysis is due either to an acute inflam-
matory process in the nuclei — comparable to the process which
produces polio-myelitis anterior acuta, and hence it is called
by Byrom Bramwell polio-myelitis acuta — or to hsemorrhagic
lesions.

The acute inflammatory cases are apt to have a sudden onset,
attended with fever, headache, vomiting, and convulsions, which
may subside after a few days, leaving only the ophthalmoplegia
behind ; and this, too, after a lengthened period, may undergo cure,
partial or complete. Transient paralysis of conjugate movements
often occur at the beginning of the attack. The intra-ocular muscles
and levator palpebrse are often spared. Sometimes these attacks
are complicated with paralysis of the facial nerve, or the diseased
process may extend to the spinal cord, and the symptoms of acute
polio-myelitis become developed ; or, again, acute bulbar paralysis
may come on.

Acute peripheral neuritis of the ocular nerves, which is sometimes
seen in cases of alcoholic poisoning, may be mistaken for acute
nuclear palsy. The symptoms of the two states are the same, except
that in the case of peripheral neuritis there are no head symptoms
at the commencement.

The onset of acute heemorrhagic ophthalmoplegia is sudden, but
is unattended by headache, vomiting, or convulsions. It takes
different courses. Sometimes it is rapidly fatal ; again, it goes on

494 DISEASES OF THE EYE. [chap. xvit.

to softeuiug of the nuclei, uud becomes chrouic ; while, again, it
undergoes a slow cure.

It is extremely probable that to this lui'morrhagic class some of
the cases of paralysis of orbital muscles belong, which occasionally
f(jllow on an attack of diphtheritic sore-throat. These paralyses
appear in from one to six weeks after the outbreak of the primary
affection. The latter need not have been of a severe kind ; indeed,
sometimes, patients are unaware that they have had a sore-throat.
These diphtheritic paralyses always recover in the course of some
weeks.

In diabetes, paralyses of orbital muscles are not very uncommon,
and are probably to be classed as nuclear. The same may be said
of orbital paralysis in lead poisoning, influenza, syphilis sometimes,
and in Gerlier's disease (Vertige Paralysant). Other causes are • —
cold, poisoning by nicotine, sulphuric acid, carbonic oxide, and
ptomaines.

The Prognosis in all these instances is favourable.

Chronic Nuclear Paralysis (Chronic Polio-encephalitis Superior,
of Wernicke) is much more common than the acute form. It de-
pends on a degenerative atrophy of the nerve nuclei, analogous to
that which occurs in progressive muscular atrophy and in chronic
bulbar paralysis. • The onset is gradual, the loss of power in
the muscles being at first very slight, but ultimately complete
paralysis of the affected muscles results. There is no fever, nor any
cerebral symptom. The condition may become associated with
chronic bulbar paralysis, with progressive muscular atrophy, or with
locomotor ataxy ; but this is not so liable to occur in infants as
in adults.

In some cases there may be partial paralysis of the orbicularis
palpebrarum, which, according to Mendel, is innervated from the
third nerve nucleus through the facial nerve, along with other
muscles of the oculo-facial group (frontalis and corrugator supercilii).

Coarse lesions, especially tumours of the pons, or of its neigh-
bourhood which press on it, may produce orbital paralyses closely
simulating those due to nuclear lesions, as we have recently observed
in a case of tumour of the pituitary body. But here the paralysis
is only one of the symptoms in the case, which are likely to include
headache, vomiting, optic neuritis, and, according to the situation
of the lesion, hemianopsia, hemiplegia, etc. Softenings, patches of

CHAP. xviT.] THE ORBITAL MUSCLES. 495

disseminated sclerosis, and internal liydruceplialus witk uver-dis-
tension of the aqueduct of Sylvius, are other lesions which may give
rise to similar orbital paralyses, but which cannot be regarded as
true nuclear ophthalmoplegia. The mode of onset, and the con-
comitant symptoms, of each case must serve as our guides in arriving
at a diagnosis, which will sometimes be difficult enough.

According to Bernheimer, the diagnosis of a nuclear paralysis
of the muscles must take into account the accompanying symptoms,
etiology, course of the disease, etc., for the grouping of the affected
muscles, whether intra- or extra-ocular, functionally associated or
otherwise, is not sufficient in itself to warrant the assumption of a
nuclear origin of the affection.

Conjugate Lateral Paralysis of the eyes is a symptom which may
be caused by a lesion in the pons. It has been generally held that
the voluntary motor impulses, coming down from the cortex to
produce associated lateral motions of the eyeballs — i.e. action of
the external rectus of one eye, along with action of the internal
rectus of the other eye — first reach the nucleus of the sixth nerve,
and then pass on under the corpora quadrigemina, through the
posterior longitudinal bands, the neurons of which connect the
sixth nucleus with the third nucleus of the same side and so
through crossed third nerve fibres finally reach the internal rectus
of the opposite side. The sixth pair of one side supplies in
this way the external rectus of its own side, and also influences
the internal rectus of the opposite side ; and it is quite probable
that similar connections may exist in the nerve supply of other
orbital muscles. Hence a lesion at, let us say, the left sixth nerve
nucleus would paralyse the conjugate lateral motions of the eyes
towards the left side ; and there would in consequence be conjugate
lateral deviation of the eyes towards the right — the eyes looking
away from the lesion. (See also p. 499.) In conjugate paralysis
or deviation, whether due to a pontine lesion, or, as will be described
in a later paragraph, to a cerebral lesion, the combined action of
the internal recti for the purpose of convergence of the eyes is
retained.

According to a more recent view the crossed fibres for innerva-
tion of the internal rectus in conjugate movements do not come
from the contralateral sixth nerve nucleus, but from the contra-
lateral third nerve nucleus, each third nerve therefore containing

liui DISEASES OF THE EYE. [chap. xvtt.

direct and crossed fibres, and the posterior longitudinal bands
contain ascending vestibulo-ocular fibres which pass up close to the
sixth nucleus, a lesion of which will not cause conjugate paralysis
unless it involve also these vestibulo-ocular fibres. The sixth
nerve contains direct fibres only.

Paralysis of the orbital muscles from nuclear disease, apart
from the primary conditions already described, may occur in
Locomotor Ataxy, Disseminated Sclerosis, General Paralysis,
Chronic Alcoholism, and more rarely in Exophthalmic Goitre and
Severe Multiple Neuritis.

* Fascicular Paralyses are mainly distinguished by the presence
of other symptoms due to involvement of neighbouring structures.
They are rarely symmetrical. Vertigo is common with fascicular
third-nerve paralysis, owing to implication of the red nucleus in
the tegmentum which is connected with the superior peduncle of
the cerebellum. Bernheimer thinks that fascicular and nuclear
paralysis are not separable clinically.

In Myasthenia Gravis the symptoms include some which are due
to derangement in the power of orbital muscles. It occurs mostly in
young people the subjects of malnutrition. Ptosis is a common symptom ;
it is usually bilateral and more marked on one side than on the other.
It may be constant, or it may only be present towards the latter end of
the day, or if the patient looks up for any length of time, when the lids
gradually fall. Owing to weakness of the occipito-frontalis muscles,
their compensatory over-action, so comiaion in other forms of ptosis, does
not occur except in the incipient stage. Weakness of the orbital muscles
with resulting diplopia is often present. Sometimes one muscle is more
affected than others, sometimes there is a general paresis affecting all the
orbital muscles, while in some cases complete and persistent ophthal-
moplegia externa is present. An alteration in the relative position of
the two images is a striking feature. In some cases irregular nystagmoid
movements are induced upon conjugate lateral motion of the eyes. The
ocular muscles, as is the case with other voluntary muscles, become readily
fatigued, the patients complaining that after reading a few lines the words
and letters run into each other. Pupil changes are exceptional, but the
pupils are sometimes unequal. In Buzzard's case, after prolonged
convergence, the pupils showed a tendency to oscillatory movements. The
power of accommodation does not become fatigued.

The general features of the disease are : — Weakness of some or all of
the voluntary muscles of the body, which may amount to complete
paralysis. After a long rest — e.g. on awaking in the morning — they may
respond normally to the will, but become rapidly exhausted after a little
use. The affected muscles often exhibit the myasthenic reaction, becom-
ing exhausted by faradic stimulation. The entire system of voluntary

CHAP. XVII.] THE ORBITAL MUSCLED. 407

muscles may be affected, but tiiose muscles are most apt to be implicated
which normally act most continuously or frequently, such as the cervical
muscles and the extrinsic muscles of the eyeball. The symptoms fluctuate
from day to day, or from month to month, and may even disappear for
months or even years, and then reappear. There are no sensory symptoms.
Death occurs in a large proportion of the cases, but no structural changes
have been found to account for the symptoms.

* Cerebral Paralyses of Orbital Muscles form the fourth and last
of the classes enumerated. They include all the orbital paralyses
due to lesions above the nuclei — i.e. in the cortex, corona radiata,
or internal capsule. They are usually associated with other symp-
toms which aid us in localising, more or less accurately, the lesions
which cause them. These paralyses are always physiological,
associated, or conjugate, as they are variously and with equal cor-
rectness termed — they are, in short, paralyses of motion rather
than of muscles.

Conjugate lateral paralysis — loss of power of motion of the eyes
to one side or to the other, while the power of convergence of the
optic axes is retained — is by far the most common form of this
symptom. We do not as yet know where the cortical centre for
the associated lateral motions of the eyes is situated.^ But even
if we did know its position, it is not likely that much would be gained
so far as clinical localisation of the cerebral lesion is concerned ;
for this centre, wherever it may be, is extremely sensitive, and is
apt to be thrown out of gear by lesions of many different parts of
the cortex. Conjugate deviation is, in short, very apt to be a dis-
tant symptom, especially in cerebral haemorrhage, when it is often
accompanied by a rotation of the head in the same direction, and
lasts only a short time. Moreover, it is thought that, when this
centre may happen to be actually involved in the lesion, its function,
being largely bilateral, is rapidly taken up by the opposite hemi-

1 This centre has been placed by various avithors in the inferior parietal
lobule (Wernicke, Henschen, Munk, etc.), and in the second frontal con-
volution (Ferrier, Horsley, and Beevor). Stimulation of the centres
of vision in the occipital lobe has also been found to produce conjugate
movements (Schsefer, Munk), and these have been regarded as reflex by
some ; but Knies holds that the visual centre contains the motor centre
for the eye-muscles as well. Moreover, it is stated that the visual cortex
contains motor pyramidal cells. The latest experiments (Bernheimer)
place this centre in that portion of the inferior parietal lobule known as
the angular gyrus.

40« DISEASES OF THE EYE. [chap. xvii.

sphere ; aud hence, even when conjugate lateral deviation plays the
part of a direct cortical symptom, it rarely can be recognised as
such, owing to its evanescent character. In paralysing lesions the
deviation of the eyes is of course towards the side of the lesion —
the eyes look at the cerebral lesion, as Prevost has expressed it —
while in irritating lesions the spasm of the afltected muscles causes
the deviation to be from the side of the lesion, that is, towards the
convulsed limbs if convulsions be present. These conditions are
the reverse of what happens in conjugate lateral deviation due to
lesions in the pons (p. 495), and we are thus enabled to differentiate
between lesions in the two positions.
There are four possible cases : —

^ , - ^ . ( Destructive. Eyes turned away from paralysed side.
Cerebral Lesions -r •. .• ^ a ^ a a

I Irritative. ,, ,, towards convulsed side.

^ . ^ . / Destructive. ,, ,, towards paralvtic side.

Pontine Lesions \ ^ ., ^. s ^ a ■ ^

\ Irritative. ,, ,, away irom convulsed side.

The cerebral cases show that the centre for associated movements
is on the opposite side of the brain — e.g. in movements of eyes to
the left, the left external rectus and right internal rectus are inner-
vated by the right hemisphere of the brain ; consequently, a destruc-
tive lesion here would produce paralysis of the left side of the^ body
and of the associated movements of the above orbital muscles,
and therefore the eyes w^ould be drawn to the right by their oppon-
ents — i.e. away from the paralysed side. A destructive lesion of
the right side of the pons would also, of course, produce paralysis
of the left side of the body ; but, involving the right sixth
nucleus (see also p. 495), it would cause paralysis of the associated
movements of the right external rectus and left internal rectus,
and, consequently, the eyes would be drawn to the left by the
opponents — i.e. towards the paralysed side.

The reverse of the foregoing would occur in irritative lesions.
Fig. 200 serves to illustrate the points referred to.

A destructive lesion at 12, the right cortical centre, involving
also motor centres of the body, would cause left hemiplegia ; and,
since the external rectus of the left eye and internal rectus of the
right eye would be paralysed, the antagonists would turn the eyes
to the right — i.e. away from the paralysed side. A destructive
lesion of the right side of the pons, also producing left hemiplegia,

XVTT.]

TEE ORBITAL MUSCLES.

409

if it involve the sixth nucleus, will produce paralysis uf the external
rectus of the right eye and of the internal rectus of the left eye,
and the antagonists would turn the eyes to the left — i.e. towards the
paralysed side. Obviously irritative
lesions would produce exactly the
opposite effects.

When the acute symptoms have
passed off, the conjugate deviation,
due to irritation, disappears even
though a conjugate paralysis and
hemiplegia may remain.

Hemianopsia interferes to a certain
extent with the conjugate movement
towards the affected side, in so far as
this is guided by visual impressions
(p. 370). According to Knies, the
difficulty in reading in right hemia-
nopsia is mainly due to this cause.

Conjugate deviations have been
found with disease of the middle
peduncle of the cerebellum, of the
pons, corpora quadrigemina, optic
thalamus, and cerebral cortex.

Some authors (Sauvineau) believe
that a lower centre exists in the
grey matter of the corpora quadri-
gemina overlying the aqueduct of
Sylvius, which regulates the associated
movements of the eyes, it would thus
constitute a supra-nuclear co-ordinat-
ing centre intervening between the cortical centre and the nerve
nuclei. Lesion of a centre of this kind would readily explain
associated vertical deviations as well as lateral deviations.

In conjugate deviations the internal rectus involved is still

Fig. 200.— 1. Left Ext.
Rectus ; 2. Left Int. Rectus ;
3. Right Int. Rectus ; 4. Right
Ext. Rectus ; 5. Nucleus left
third nerve ; 6. Nucleus right
third nerve ; 7 and 8 Post,
longitudinal bands from sixth
nerve to opposite third nerve ;

9. Nucleus left sixth nerve ;

10. Nucleus right sixth nerve ;
11 and 12. Left and right cor-
tical centres. An impulse
starting from 12 would travel
down to 9, and produce an
associated movement of the
eyes to the left.i

1 According to Bernheimer's view, in the above diagram 9 (6th nucleus)
would be connected with 5 (3rd nucleus of same side) and from 5 some
fibres would also pass into the opposite 3rd nerve through 6. It simply
means that the decussation would take place lower down.

r.OO DISEASES OF THE EYE. [chap. xvii.

capable of taking part in the act of convergence ; moreover, diplopia
does not occur since there is no strabismus.

It seems important here, even at the lisk of some repetition, to
direct special attention to

^= The Localising Value of Paralyses of Orbital Muscles in Cerebral
Disease. — Paralysis of the Third Nerve. As regards this nerve we
are struck with the fact that ptosis, partial or complete, may be
present as a focal symptom in cortical lesions — cerebral ptosis, as it
is called — without any other third-nerve branch being paralysed.
That a separate cortical centre for this branch of the third nerve
exists, and that it innervates the muscle of the opposite side, is very
probable. The existence of such a centre would not be inconsistent
with the view that, as regards the motions of the eyeballs, associated
centres alone are present ; for, although as a rule the elevators of
the lids are associated in their motions, yet by an effort of the will
most people can throw one of them into motion separately, or more
than the other. No doubt the power to voluntarily innervate one
levator and orbicularis alone varies in different individuals, and in
many persons the levator centres are practically associated centres,
and probably this is the reason w^hy cerebral ptosis is rather rare.
The position of this centre is still an open question, but it is believed
to be situated in front of the upper extremity of the ascending frontal
convolution close to the arm centre.

Ptosis, then, has no value as indicating the locality of a lesion in
the cortex ; but it may be of use in distinguishing a cortical lesion
from one situated elsewhere in the brain, for monolateral ptosis, as
the only focal symptom, occurs with cortical lesions alone.

It is probable that ptosis, as the result of a cortical lesion, is a
distant symptom in not a few of the cases where it is present.

Ptosis on the side of the lesion has occasionally formed a symptom
in disease of the pons, without paralysis of the other branches of the
third nerve — except, sometimes, in so far as conjugate deviation
{vide supra) is concerned — and without the third nerve being involved
in the lesion.

Again, ptosis, by forming a factor of a crossed paralysis, may
serve to localise a lesion in the crus cerebri. When the third nerve
is paralysed by a lesion in this situation it is the rule to find it para-
lysed as a whole ; but paralysis of only some of the third-nerve
branches may be produced by a lesion of the cerebral peduncle, and

CHAP. XVII. 1 THE ORBITAL MUSCLES. 501

the branch to the levator palpebrse seems to be the one most fre-
quently implicated alone.

To complete the subject of ptosis, mention must be made of
Sy7n/pathctic Ptosis which is accompanied by other eye-symptoms,
as well as by symptoms of vasomotor paralysis of one side of the body,
such as elevation of temperature, and redness and oedema of the
skin. In these cases, there is (1) apparent ptosis on the paralysed
side, owing to the contraction of the palpebral aperture, but the lid
can be raised ; (2) contraction of the pupil on the same side ; (3)
diminished intra-ocular tension ; (4) a shrinking back of the eyeball
into the orbit, so that it seems to have become smaller ; (5) an ab-
normal secretion of thin mucus from the corresponding nostril, of
tears from the affected eye, and of saliva from the corresponding side
of the mouth. In the later stage, the side of the face becomes paler
and thinner, its temperature is lower, and it perspires less than the
other side, or not at all. This train of symptoms has been found in
lesions of the corpus striatum, but is chiefly due to lesions of the
cervical sympathetic, or of the spinal cord at or above the level of
the eighth cervical and first dorsal nerve, or of these nerves alone.

A common sign of disease of the crus cerebri is what is known as
Crossed Hemiplegia. Paralysis of the third nerve, on the side of the
lesion, with hemiplegia, hemiansesthesia, often facial, and sometimes
hypoglossal, paralysis on the opposite side of the body is a frequent
form of it. The lesion may implicate all the branches of the third
nerve, or only some of them. The optic tract lying as it does close
to the crus may also be affected by the lesion which would then give
rise to hemianopsia on the same side as the hemiplegia. But the
localising value of crossed hemiplegia, as Hughlings Jackson long
ago pointed out, depends chiefly on the hemiplegia and paralysis of
the cranial nerve coming on simultaneously. If they occur at differ-
ent times they may be due to two distinct lesions, neither of which
may be in the crus ; for the hemiplegia might be due to a lesion in
the hemisphere, and the third-nerve paralysis to a basal lesion of
earlier or later date. Yet a few cases have been observed where,
with a lesion in the cerebral peduncle, the third-nerve paralysis
preceded the hemiplegia by a considerable interval.

That basal lesions are by far the most frequent cause of paralysis
of the third nerve is beyond doubt : and here it is usual, but not
constant, to find it paralysed in all its branches. The diagnosis to

502 DISEASES OF THE EYE. [chap. xvii.

be made, when direct symptoms are being considered, is, for the
most part, between a lesion in the crus and a lesion at the base. We
cannot pretend to be able to make this diagnosis with certainty in
all cases. Complete paralysis of every branch of the third nerve
without any other paralysis is almost always basal ; so also are those
cases in which, where there is hemiplegia, it is slight, as compared
with the degree of the third-nerve paralysis ; and those cases, too,
to which reference has already been made, where there is an interval
between the onset of the paralysis of the extremities and of the
third nerve, are apt to be basal. Of course there may be such a
combination of paralyses of the other cerebral nerves with that of
the third nerve, as to leave no doubt with reference to the basal
position of the lesion.

The third nerve may be paralysed by lesions in the inter-pedun-
cular space, in which case the paralysis may be partial (ptosis alone,
or abolition of upward and downward motion alone), complete,
monocular, or binocular. This is the commonest situation for a
syphilitic basal affection, which may extend in a forward direction
and involve the chiasma as well. When both nerves are affected
there is generally also paralysis of the other orbital nerves, or of the
facial nerve ; and hemiplegia or hemianopsia may also be present.

Thrombosis of the Cavernous Sinus invariably produces paralysis
of the third nerve ; but all the orbital nerves, as well as the fifth
and the optic nerve, may also be involved, giving rise to complete
immobility of the eye, with loss of conjunctival and corneal sensa-
tion. The pupil is usually contracted at first, but later on dilates.
The venous obstruction causes exophthalmos, oedema of the lids, and
chemosis. The ophthalmoscope sometimes shows the presence of
congestion papilla. The general symptoms are rigors, high tempera-
ture, and vomiting. Its principal causes are infective inflammation
of the orbital cavity or nasal sinuses ; erysipelas of the face ; infec-
tive inflammation in the buccal, nasal, and pharyngeal cavities,
and of the body of the sphenoid ; and extension of thrombosis
of the sinuses from purulent otitis. The thrombosis in more than
half the cases spreads to the other side through the circular sinus.
When the invasion occurs from the intracranial direction, pain in
some or all of the branches of the fiist division of the fifth nerve
is usually an early syin])t(^in.

Third-nerve symptoms — in addition to those included uiuler the

CHAP, xvii.l THE ORBITAL MUSCLES. 503

headings conjugate deviation, or paralysis, and ptosis — are some-
times distant symptoms. Tumours of the cerebral hemispheres,
more particularly if accompanied by violent general head symptoms,
indicating probably high intracranial pressure, are the lesions most
apt to produce these distant third-nerve symptoms. As a rule, the
slighter the general cerebral symptoms, the more likely are the third-
nerve paralyses to be direct symptoms. This rule, indeed, applies
to other as well as to third-nerve focal symptoms.

Paralysis of the Fourth Nerve, when combined with paralysis of
other motor eye-nerves, is difficult to recognise ; and consequently
in such cases it furnishes but little aid for localisation. Solitary
paralysis of this nerve as a symptom of cerebral focal lesion is ex-
tremely rare. Nieden has placed a case on record in which paralysis
of one fourth nerve was the only focal symptom to which a tumour
of the pineal gland, of the size of a walnut, gave rise. But the
isolated fourth-nerve paralysis is more apt to be produced by a
basal lesion. Pfungen has pointed out that, in meningitis, exudation
in the space between the corpora quadrigemina and the splenium
of the corpus callosum may implicate the fourth nerves in the valve
of Yieussens, and believes it is prone to do so in tubercular mening-
itis. In combination with paralysis of the third nerve it speaks for
a lesion in the cerebral peduncle, extending back to the valve of
Vieussens.

Pseudo-paralysis of the fourth nerve, usually only transitory,
sometimes occurs after radical operations on the frontal sinus, from
displacement of the pulley of the superior oblique muscle.

When Paralysis of the Sixth Nerve occurs as the only focal sign
it is probably due to disease at the base, or it is a distant symptom.
There is no cranial nerve so liable to provide a distant symptom as
the sixth. Gowers refers this liability to the lengthened course this
nerve takes over the most prominent part of the pons, which renders
it readily affected by distant pressure. One or both nerves may in
this way be paralysed. Wernicke states that sixth-nerve paralysis
is most apt to be present as a distant symptom, when the lesion,
especially a tumour, is situated in the cerebellum ; differing in this
way from the third nerve, which is more likely to give distant
symptoms with a lesion in the cerebral hemisphere.

Paralysis of the sixth nerve, simultaneous in its onset with
hemiplegia of the opposite side of the body, indicates a lesion in the

504 DISEASES OF THE EYE. [chap. xvii.

pons, usually a ha3morrliage, on the side corresponding with the para-
lysed nerve. We know that the fiftli and facial, and sometimes the
auditory, spinal accessory, and hypoglossal nerve, may all, in varying
combinations, form one of the elements in a crossed paralysis from a
lesion in this position ; but if special localising value is to be given
here to the participation of any one cranial nerve, that nerve is the
sixth. The paralysis of this nerve, simultaneously with palsy of
the opposite side of the body, while other conditions point to an
intracranial lesion, speaks, then, almost certainly for pontine disease.

Basal paralysis of the sixth nerve is frequently double, especially
in syphilis. Fracture of the apex of the petrous portion of the
temporal bone may also cause it.

Paralysis of the facial with the sixth is not an uncommon com-
bination caused by a lesion in the pons, which at the same time
produces hemiplegia of the opposite side of the body. This com-
bination is a natural one, in view of the close relations of the nuclei
of the sixth and seventh nerves. The manner in which the root of
the facial nerve winds round the sixth-nerve nucleus must also have
an important bearing on the occurrence of associated paralyses of
these nerves.

Paralysis of one or both sixth nerves sometimes occurs in con-
nection with a purulent otitis media without any symptoms of
intracranial complications, and is not usually a sign of serious
importance, although in some cases it may be the first symptom of
intracranial mischief. It is probably due to a localised area of
infection, causing slight meningitis or necrosis at the apex of the
petrous bone or the infective material may be carried up through the
carotid canal, but on the other hand it may be reflex in character,
and may be brought about by the connection of the sixth nerve
with Deiter's nucleus into which the vestibular nerves pass.

Hemiplegia due to a lesion of the cortical motor region, wliich
might happen to be combined with paralysis of the sixth nerve as a
distant symptom, offers no difficulty in its diagnosis from hemiplegia
with sixth-nerve paralysis in pontine disease ; for, while in the
latter the paralysis is crossed, in the former it is homonymous.

Parah/sis of the Seventh Nerve. When lagophthalmos occurs as
a symptom in focal cerebral disease, it is useful in localising the
disease by assisting in differentiating a lesion in the internal capsule,
or in the facial motor centre of the cortex, from one implicating the

CHAP. XVII.

THE ORBITAL MUSCLES.

505

portio dura in the pons, as it is absent, or very slight, in the former
cases, but very often markedly present in the latter. With a lesion
in the lower part of the pons we are apt to have la,Lfoplithalmos with
crossed hemiplegia ; but if the lesion be in the upper part of the
pons — the fibres from the opposite side having here joined the
motor tract — the hemiplegia and lagophthalmos will be homony-
mous.

Paralysis of the Fifth Nerve, with hemiplegia of the opposite
side, points to disease in the pons. Neuroparalytic ophthalmia is
said to be the rule in basal lesions of the fifth nerve, and to occur
very rarely in nuclear or fascicular lesions.

The Orbicular Sign may be noticed in some attacks of apoplexy
with hemiplegia after consciousness has returned. It consists in
this, that the hemiplegic person, who during health has been able
to close each eye separately, and who even now can close both eyes
together, or the eye on the sound side alone, is unable to close the
eye on the paralysed side by itself. This sign usually passes away
after a short time. Sometimes when both eyes are closed it requires
a greater effort to bring the eyelids together on the paralysed side.

Extensive basal lesions, especially those due to syphilitic disease,
may produce symptoms due to involvement of widely separate
structures, without interfering with those which intervene ; hence
they tend to implicate several nerves
without reference to system or function.

* Congenital defects of motion of
the eyes are not very uncommon,
and are sometimes hereditary. Ptosis
(chap, xviii.) with, or without defect of
upward movement of the eyeballs, is
the commonest form, and is often asso-
ciated with epicanthus (Fig. 201), but
all degrees of impairment of mobility,
and even total loss of motion, may be
met with, as well as unnatural asso-
ciated movements of the eyes. In
paralysis of outward movement, re-
traction of the eyeball occurs in some

cases on looking inwards. The powdr of convergence is frequently
retained, although lateral movement may be impaired or ab-

Fig. 201. — Congenital ptosis
with epicanthus.

)0r> DISEASES OF THE EYE. \chav. xvii.

sent. The pupils and accommodation escape as a rule. There
is no diplopia or secondary deviation as in acquii-ed paralysis.
(According to Duane secondary deviation does occur and diplopia
can be induced.) Vision is usually impaired, and the patients are
often mentally dull. The defective mobility is due to absence or
defect (aplasia) of the muscles, nerves, or nuclei. For congenital
ptosis with associated lid-movement see chap. xvii.

Strabismus Fixus is a rare condition in which both eyes are
turned inwards to an extreme degree and practically immovable.
It is probably the result of a form of congenital ophthalmoplegia.
It is almost impossible to remedy it by operation owing to secondary
contracture of the muscles, and probably also of the capsule of
tenon.

Convergent Concomitant Strabismus (Non-Paralytic
Strabismus).

This is the condition which is popularly known as inward ' cast '
or ' squint.' It makes its appearance in children, when they begin
to take an interest in small objects, such as toys and pictures ; or
a little later, when the first lessons are learned — in short, when they
begin to make frequent and prolonged demands on their internal
recti and accommodation, most commonly from the age of three to
six years.

It is non-paralytic, and the term ' concomitant ' {concomitatus ,
accompanied) is given to it in contradistinction to ' paralytic '
strabismus, because in it the squinting eye accompanies the straight
one in all its movements to an equal extent. In the primary position
of the eyeballs, in a case of concomitant squint, the parallelism of
the visual axes is defective, and, as the eyes are moved from side to
side, the defective parallelism continues in the same degree, neither
increasing nor decreasing Moreover, the secondary deviation (p.
477), in the sound eye, in these cases of concomitant strabismus, is
equal in degree to the primary deviation of the squinting eye ;
because the internal rectus of the good eye being associated in its
action with the external rectus of the squinting eye, when the latter
)nuscle is forced to roll its eye outwards in order to bring it to fixa-
tion, tlic iiiteiiial rectus of tlie g(»o(l eye, receiving a similar nervous
impulse, rolls that eye inwaids to the same extent as the squinting

CHAP. xviT.] THE ORBITAL MUSCLES. 507

eye has been rolled outwards. The good eye will therefore present,
under the covering hand, an internal strabismus of the same amount
as that which has previously been present in the squinting eye.
This is an important point, for it is an aid in the differential diagnosis
of this form of strabismus from the paralytic form, in which the
secondary deviation is greater than the primary one (see General
Principle No. 2, p. 477). Diplopia and giddiness are absent in
concomitant strabismus.

In concomitant strabismus, both eyes never squint simultane-
ously, as one hears it sometimes stated by parents ; although the
excessive convergence, as will be explained later on, is present in
both.

The method of distinguishing the squinting eye from the fixing
eye is given at p. 472.

Bonders pointed out that, in a large proportion of cases of con-
vergent strabismus, the refraction is hypermetropic ; and he drew
the conclusion that hypermetropia is to be regarded as the cause of
the strabismus in the following way : — It has been shown (p. 8)
that with each degree of normal convergence of the optic axes, for
the purpose of single vision, a certain effort of accommodation, in
order to see the object distinctly, is associated. The greater the
angle of normal convergence, the greater is the possible effort of
accommodation.

Of this physiological fact, Bonders said, the hypermetrope often
unconsciously takes advantage, and in order to brace up his ac-
commodation in an excessive degree for the sake of distinct vision
with one eye, he increases the angle of convergence of the optic
axes.

The over-convergence is not, however, as usually described,
limited to the squinting eye ; both take part in it, and the effect
is to render the strabismus manifest in the eye which does not fix.
To explain this it may be desirable to consider what occurs, when
convergence and accommodation are normal. In Fig. 202 the eyes
are converging on, or fixing, the point 0, and the object is seen singly,
and at the same time distinctly, because the amount of accommoda-
tion required is normally associated with this degree of convergence.
Although the right eye (R) is in the primary position, it is taking
part in the act of convergence as much as the left eye (Fj). If
were at 0', at the same distance from the eyes but in the middle

508

DISEASES OF THE EYE.

[chap. XVII.

202. — Binocular
with convergence and accommoda-
tion for O.

line, L and R would converge through equal angles, a and h. Now,

if the eyes make a lateral movement to the right (arrow 3), the de-
viation of L would be made up of
the angles a and c, a being due to
convergence, and c to the lateral
movement in the same direction,
both brought about by the left
internal rectus ; whereas the con-
vergence in R (arrow 2), due to
the internal rectus, is neutralised
by the lateral movement (arrow
3) which is in the opposite direc-
tion in this eye. If this eye had
not been converging, it would
have remained parallel to L
in the lateral movement, and
would have moved outw^ards.

L is considerably rotated inwards, but it is not squinting, because

it is fixing 0.

Fig. 203 represents concomitant convergent strabismus.

The patient wishes to see

the object at distinctly,

but owing to his hyperme-

tropia, the accommodation

normally associated with this

degree of convergence is not

sufficient. By converging for

a nearer point (B) an addi-
tional effort of accommoda-
tion can be made, but then

the patient could not fix 0,

and it would appear double.

In order to avoid this di-
lemma a lateral movement of

the eyes is made from B to

B'. and thus the right eye (R)

is brought into lino witli O,

and sees it distinctly by mean;

gained l)y convergence for B,

Fig. 203. — Concomitant convergent
strabismus ; binocular convergence for
B' with monocular fixation, and ac-
commodation for O.

i of tlio additional accommodation
Tlie left eye now Jio longer fixes 0,

riTAP. xvTT.l THE OnniTAL MUSCLES. 500

and therefore squints. The deviation of the squinting eye is made
up of the angles a (excess of convergence for B) and c (lateral move-
ment to B"). In the right eye, the excess of convergence is neutra-
lised by the lateral motion in the opposite direction. In fact, it is
only the desire for fixation which keeps both eyes from squinting.
In some cases there is no lateral movement, as the patient turns his
head, in the above case to the right, to bring the right eye into line
with 0.

Inasmuch as all hypermetropes do not squint, Donders con-
sidered that there were contributing circumstances, which caused
each hypermetrope to unconsciously decide between distinct mono-
cular vision with strabismus, and indistinct binocular vision. The
latter, he said, is likely to be preferred if the condition of the refrac-
tion and the acuteness of vision is the same in each eye ; while, if
one eye be amblyopic, or if the retinal images differ much, by reason
of one eye being more ametropic than its fellow — from nebulous
cornea, or from other causes — the desire for binocular vision would
be less strong, and the imperfect eye would deviate inwards for the
sake of the resulting increase of accommodation in the perfect eye.

It is admitted that hypermetropia is one of the causes of internal
strabismus, but it is not the only cause, and probably not even the
principal cause, for the following reasons : — (1) If Donders' theory
be complete, convergent strabismus must always appear, whenever
there is binocular hypermetropia, along with the conditions which
reduce the value of binocular vision. But strabismus is often absent,
while the degree of ametropia is markedly different in the two eyes,
or while the acuteness of vision is very defective in one eye. Again,
the number of cases of strabismus is very small in proportion to
the number of hypermetropes, since nearly all children are hyper-
metropic. (2) In periodic strabismus, the influence of hyperme-
tropia and of the accommodative effort is very evident ; and yet
these cases only go to show that, while hypermetropia is very fre-
quently one of the causes of strabismus, it is not the only or most
important one ; for here, clearly, some factor necessary for the
production of a permanent squint is wanting. (3) Donders' theory
fails to explain the occurrence of convergent strabismus in emme-
tropic and in myopic individuals, where, of course, no excessive
effort of accommodation is required.

The fact that very few squinters are found amongst high hyper-

510 DISEASES OF THE EYE. [chap. xvii.

metropes is not an argument against Donders' theory, as high
degrees of this error are met with much less frequently tlian low
or moderate degrees, moreover the demand on the accommodation
in such cases may be so great that over-convergence does not enable
the patient to obtain sufficient accommodation for distinct vision.

Congenital want of equilibrium between the muscles has been
advanced as an explanation of convergent squint, but no proofs
of this preponderance of certain muscles can be given.

Spontaneous cure of strabismus sometimes takes place, most
commonly between the tenth and sixteenth year of age. That it
may happen with hypermetropia, and with defective vision in one
eye, is strongly against Donders' theory, assuming, of course, that
the hypermetropia has not diminished much, as it naturally tends
to do at this time of life.

The most probable cause is defective development of the sense
of fusion (p. 473), aided or caused by conditions which render fusion
difficult, such as hypermetropia, or amblyopia, either congenital,
or acquired in early life. Illness may weaken accommodation, and
the temporarily altered relation between the latter and convergence
may cause a squint to appear even in emmetropia, if the sense of
fusion be imperfect. In alternating strabismus, where the patient
squints with either eye, the vision is generally good and equal in
both eyes ; yet, according to Worth, the faculty of fusion is always
wanting in these cases.

Priestley Smith upholds the theory of the defective development
of the sense of fusion, which is acquired, as stated before, in infancy.
During the first few years of life, this newly acquired faculty is less
stable than at a later period, and is more easily disturbed. Hence
the greater liability to strabismus in infancy. Among three hundred
and forty-seven cases, where the onset age was ascertained, two
hundred and fifty-four, =: 73 per cent., began before the children
were five years old. Three years was the most common age. The
hypermetropic child is specially liable to convergent strabismus,
because he has to overcome a special difficulty : he must learn to
converge normally, while he accommodates abnormally. Failing
in this, he squints in order to see clearly. Many squints arise in
this way, but the influence of hypermetropia must not be exagger-
ated.

Infantile disorders — convulsions, whooping-cough, measles, a

cuw. xvn.] THE ORBTTAL MUSCLES.

fright, a fall, etc. — are often the starting-point of strabismus,
because the controlling influence of the higher brain centres is
weakened at such times. Priestley Smith believes that a con-
tinuous squint involves weakening or loss of visual function, and
that the younger the child the more readily does this occur. The
sense of fusion, being no longer exercised, is gradually lost, and
may prove irrecoverable a few years later, even though the eyes
be made straight. Furthermore, an eye which never fixes the
object at which the patient looks, loses the power of true fixation.
Such loss is found most often amongst cases of early onset and
long duration ; it is rarely, if ever, found until the squint has become
continuous for at least six months. Again, it is probable that the
early onset of strabismus, with complete disuse of the squinting eye,
may arrest the development of form-perception in the latter, and
thus render it permanently amblyopic.

Single Vision in Concomitant Strabismus. — For the most part these
patients do not complain of double vision, as in cases of paralytic strabismus.
Why is this ? The image of the object looked at, it will correctly
be said, must be formed in the squinting eye in each of these kinds of
strabismus, on a part of the retina not identical with that in the fixing
eye, but lying to the mesial side of it ; and hence the image of the object
should be projected by the squinting eye to its own side of the true position
of the object (homonymous diplopia), and the latter should therefore be
seen doubled. It is seen doubled in the paralytic form ; why not also in
the concomitant form ? The explanation commonly given is that con-
vergent concomitant strabismus being a quasi-physiological condition, the
patient's mind involuntarily suppresses the annoying image belonging to
the squinting eye, in a manner analogous to that by which, when we are
deeply interested in conversation, all extraneous sounds are unperceived,
although they, too, must reach the nerve of hearing. This suppression
of the image belonging to the squinting eye was believed to be the more
easy owing to the indistinctness of the image itself, formed as it is on a
peripheral part of the retina, while in the good eye it falls on the macula
lutea. We often find, moreover, that the squinting eye is ab inito more
defective (macula cornea, higher degree of hypermetropia, astigmatism,
etc.) than its fellow, and it was held that this, too, rendered suppression
of its image more easy. Such a suppression of the image is possible, and
it no doubt does occur in many cases of strabismus ; but it is certain that
it does not occur in all of them, perhaps not even in the majority of them.
The suppression affects only the macular region, for the remainder of the
field of the squinting eye is made use of by the patient.

In those cases in which the image of the squinting eye is not suppressed,
one of two events takes place : — Either the region of the retina, on which,
in the squinting eye, the image of the visual object is formed, becomes

12 DISEASES OF THE EYE. [ciiap. xvtt.

functionally developed into a spot to a great extent physiologically
' identical ' with the macula lutea of the straight eye, and then something
approaching normal binocular fusion of the images comes about, and
hence single vision ; or else, diplopia is actually present, although, as a
rule, it passes unnoticed by the patient, owing to its having become
habitual to him. In some cases the first of these conditions is the actual
state, in others it is the second which exists. In support of the first is
the occurrence, not rarely observed, of crossed diplopia after operation
for concomitant convergent strabismus, even when there is no divergence
produced ; and in support of the second, the diplopia which intelligent
patients often admit, when they are carefully examined with the aid
of a red glass before the good eye. If the strabismus be the result of a
want of development of the faculty of binocular vision, then the absence
of diplopia need not be a matter for surpris3.

Amblyopia of the Squinting Eye. — In a large proportion of the cases
of internal concomitant strabismus the squinting eye — even where there
is no marked astigmatism, and where the media are clear — is amblyopic.
It has been a very generally accepted opinion that this amblyopia is due
to want of use on the part of the squinting eye, in consequence of the
suppression of the image on its retina, and hence it is termed amblyopia
ex anopsia. According to Schweigger, if this viiew were the correct one,
we ought always to find only slight amblyopia of the squinting eye in
children soon after strabismus comes on ; while it should be of high degree in
adults who have not been operated on, and in whom mono lateral strabismus
had been present since childhood. And yet marked amblyopia may often
be found in children in the squinting eye, while in adults the squinting
eye often has very good vision — in short, the amblyopia of the squinting
eye is not progressiv^e, as it would be were it ex anopsia. Again, "many
squinting eyes, when the straight eye is covered, instead of fixing the
visual object with the macula lutea, remain unchanged in position, or
even turn inwards more than before (amblyopia with excentric fixation) ;
and in less well-marked cases of the same sort, although there is no excen-
tric fixation, yet the preference for fixation with the macula lutea is lost,
and uncertainty of fixation results, no one part of the retina being more
useful for that purpose than another. It is held by many that this form
is characteristic of amblyopia ex anopsia, and is the result of the strabismus ;
but it is identical with a form of congenital amblyopia, sometimes present
without strabismus in one eye only. Worth, however, points out that
in these cases there is greater error of refraction in the amblyopic eye, and
that even in spite of the amblyopia the fusion sense is well developed.
A strong argument in favour of amblyopia ex anopsia is the improvement
which often seems to take place in the vision of the squinting eye by
systematic separate use, or after the strabotomy. Schweigger thinks that,
where the improvement takes place, the defective vision has been due
rather to retinal asthenopia than to amblyopia ; and if, at the outset,
patients be pressed to discern the test-types, they often succeed in producing
a better acuteness of vision than they at first seemed to possess. In many
cases, separate use fails altogether in improving the vision of the squinting
eye, even when it is not very defective — a fact which is unfavourable to

CHAP. XVII.] THE ORBITAL MUSCLES. :a\\

the amblyopia ex anopsia theory. The circumstance that in alternating
strabismus the sight of each eye is good, cannot be regarded as proof in
favour of amblyopia ex anoj)sia. Some believe that the amblyopia in
the squinting eye is congenital ; and, far from being the result of the
strabismus, is a factor in its production, just as opacities of the cornea,
or high degrees of ametropia, have always been admitted to be. The
views of different observers vary greatly on this point, and depend very
much on the age of the patient wlien first treated, on tlie inethods employed
for testing and developing the ^'ision, and on the perseverance of the
surgeon, and of the patient's parents. Except in cases of very defective
vision where there may be a central scotoma (not specially for any par-
ticular colours) the field of vision is normal in the amblyopia eye.

Worth's views are similar to Priestley Smith's. He believes that
tlie power of central fixation is lost very rapidly in infancy, and that
the earlier the onset of the strabismus the greater will be the amblyopia.
After six years of age, amblyopia ex anopsia seldom takes place to any
great extent. This weakens Schweigger's argument based on the non-
progressiveness of the amblyopia.

There are Three Clinical Varieties of Convergent Concomitant
Strabismus. — (1) Periodic. (2) Permanent alternating. (3) Per-
manent monolateral. Periodic strabismus occurs only now and
again, perhaps when a greater effort of accommodation is required.
It is sometimes the first stage of permanent monolateral, or of
alternating strabismus ; but these two latter forms do not always
have their beginning in the periodic form, which often continues
as periodic to the end of the chapter. In alternating strabismus
the patient squints with either eye indifferently. In permanent
monolateral strabismus the squint is confined to one eye.

Measurement of Convergent Strabismus. — The amount or degree
of the deviation of the squinting eye is measured by one of the
following methods. In all of them it is important that the patient
be directed, during the test, to regard an object placed in the median
line and on a level wdth his eyes (the Primary Position, p. 466).
The angle of the squint usually increases with accommodation when
the object of fixation is near.

1. Hirschberg's Method consists in making the patient fix a
candle flame, or the ophthalmoscope mirror, held straight in front
of, and about a foot from, the eyes, when the observer estimates
the degree of deviation by the position of the corneal reflex. Where
there is no squint, this reflex is situated at, or (with large angle y)
slightly to the inner side of, the centre of the pupil in each eye.
In a convergent squinting eye it is displaced outwards, and Hirsch-
33

r)i4

DISEASES OF THE EYE.

[chap. xvtt.

berg recognises five groups of strabismus. Group 1 (Fig. '204: re-
presenting the riglit eye), in which the leHex is nearer to the centre
than to the margin of the pujjil. This represents a strabismus of
less than 10''. Group 2, in wliich the lefiex is at or about the margin
of tlie pupil, representing a strabismus of 12^ to 15°. Group 3, in
wliicli the reflex is outside tlie pupilhny margin, about lialf-way
between tlie centre of the pupil and tlie corneal margin. This

iSSf

y^ ^^ murytn of '
f ^^' Tn^c(itum.(5m'ni)jjupit

\ 1 iTk)' )

,/•

/ / y-J_^ cornect .

^ ^'i J

Fig. 204.

represents a strabismus of about 25°. Group 4, in which the reflex
is on or near the corneal margin, represents a strabismus of 45° to
50°. Group 5, in which the reflex is on the sclerotic, between the
margin of the cornea and the equator bulbi. This represents a
strabismus of 60° to 80°. This is a modification of the linear method,
and is a convenient one in routine practice.

2. Priestley Smith measures strabismus by means of a double
tape (Fig. 205), used in conjunction wdth the ophthalmoscope, as
shown in the accompanying figures. The patient places the ring
P on one of his fingers, and holds it to his cheek. The observer
places the ring on the forefinger of the hand w^hich holds the oph-
thalmoscope ; this keeps his eye at a distance of one metre from the
patient's face. He uses his disengaged hand as a fixation object
for the patient, holding it edgewise towards the patient, and letting
the graduated tape slide between his fingers. A small weight at
the end of the tape keeps it stretched, as the hand moves in either
direction.

Fig. 206 illustrates the measurement of a convergent strabismus
of the right eye. The patient, seated below the lamp and holding
the tape as above described, is told to look at the mirror. The
observer, holding the ring and the mirror in the right hand, throws
the light on the patient's left eye (L) — i.e. the fixing eye. He sees

CHAP. XVTI.]

THE ORBITAL ^rT'SCLf:S.

the corneal reliex in the centre of the pupil, and knows thereby that
this eye is fixing properly. He then throws the light on the right
eye (R), and sees the reflex situated eccentrically outwards, and
knows that this eye deviates inwards. Taking the graduated tape
between the fingers of his left hand, and telling the patient to watch
this hand, he moves it outwards along the tape, and meanwhile
watches the corneal reflex in the deviating eye. When the reflex
reaches the middle of the pupil the observer reads the position of
the hand upon the tape. The axis of the deviating eye (/?) has
moved from R' to 0, through the angle R' R 0. The axis of the
non-deviating eye {L) has moved through an equal angle (0 L U).

Fig. 205.

P o —

— ~<o

The angular movement of L, as measured by the tape, equals the
angular deviation of R.

Fig. 207 illustrates the measurement of a divergent strabismus
of the right eye. The hands are reversed, but the principle of
course is the same as before.

Maddox's tangent scale, and Worth's deviometer in which an
electric light is flashed on the cornea, are based on the same principle,
and are very useful, the latter especially so, for infants.

The graduated tape is in fact a substitute for a graduated arc
of a circle, and represents the tangents of the angular deviations.

In this mode of measurino- a strabismus it is the exci

of the

51(>

DISEASES OF THE EYE.

[chap. XVII.

fixing eye which is actually measured, aucl the excursion of the de-
viating eye is taken to be equal to it. If the excursions of the
eyes be unequal, that is to say, if the strabismus be not a con-
comitant one, the result is faulty. The method, though difficult to
explain in woids, is quick and satisfactory in practice.

3. Perimeter Method. — The object aimed at here is to determine
the size of the angle, which the visual axis of the squinting eye
makes, with the direction it should normally have. For this pur-
pose a perimeter is employed. Let us suppose that the right eye

Fig. 208.

{R, Fig. 208) be the squinting eye, and that P o P be the arc of the
perimeter. The patient is placed at the instrument, as though the
field of vision of his squinting eye were about to be examined. He is
directed to look at a distant object {A) with his good eye (L). The
visual line from B should now pass through the point o, but it passes
through the point n, and therefore o R n is the angle of the strabis-
mus. The surgeon finds the position of n by carrying the fiame of a
candle along the perimeter, until, with his eye placed behind the
flame, he finds that the corneal image of the fiame occupies the
centre of the pupil. The fiame itself will then be at n, and the size

CHAP. XVII.] THE ORBITAL MUSCLES. 517

of the squint-angle may be read off there. This gives the optical
axis of the eye ; but, to be strictly accurate, we must remember that
the position of the visual axis is what is required, and that it lies a
few degrees farther inwards, according to the size of the angle.

4. Tangent Strabismometer. — Maddox's tangent scale can be
used to determine the angle of strabismus subjectively, by means of
the diplopia if it be present, and also objectively, by the observation
of the corneal reflex ; in the latter respect it is only a modification
of Priestley Smith's method. The scale has two sets of figures,
large ones for a distance of five metres, and smaller ones for a distance
of one metre. At the centre, or zero point, a candle is fixed, and
also a string one metre long for adjusting the distance of the patient.
The figures on one side of the zero are red, and on the other black.

When diplopia is present, the patient is merely asked to indicate
the figure opposite to which the false image of the candle appears.

In the objective method, the surgeon stands with his head below
the zero of the scale, facing the patient ; he then notes the eccentric
position of the corneal reflex of the candle in the deviating eye ;
and, estimating the amount of the squint, directs the patient to
look at this figure on the scale. If the estimate be correct, the
reflection w411 be in its proper position on the cornea ; if it be not,
the patient is directed to look at other figures higher or lower, as
the case may be, until the position of the reflex is correct.

* Mobility of the Eye in Convergent Concomitant Strabismus. —
In cases of long standing, the mobility is often defective in the
squinting eye, and sometimes also in the fixing eye. The method
of measuring the excursions of the eyes has been described on
p. 471. In strabismus we simply compare the outward mobility
of the squinting eye with that of the good eye, to ascertain how
much, if anything, the former lacks of its normal amount.

Before undertaking the treatment of a case of convergent
strabismus, in addition to the points mentioned, the power of
fixation of the squinting eye, the presence or absence of diplopia
and the sense of fusion, the refraction, and the acuteness of vision,
should all be asceitained. For testing the vision in very young
children, Worth lias suggested ivoiv balls of different sizes which
are thrown on the floor and which the child is asked to pick up.

Treatment of Concomitant Conveiyent Strabis7)ms. —

(a) Optical Treatment. The total hypermetropia, and the astig-

518 DISEASES OF THE EYE. [chap. xvii.

matism, if any, must be corrected, and the glasses must be worn
constantly. In young children, atropine must be used to determine
the refraction, and it should be continued until the glasses have been
worn for some time. Some sui-geons order glasses for infants of
twelve months or even less. The glasses frequently diminish or
remove the strabismus while being worn. They act by removing
the strain on the accommodation and also by improving the vision.

(b) Orthoptic Treatment. — To Javal is due the credit of devising
this method. It consists in preventing the development of amblyopia,
and in training the sense of fusion. To attain the first object, com-
plete occlusion of the fixing eye for a certain period every day is
necessary. Instillation of atropine in the fixing eye is also very
serviceable and may replace the bandage, it frequently causes the
strabismus to change over to this eye, especially when the originally
squinting eye is used for near vision. When the vision is sufficiently
improved, the training of the fusion sense should be undertaken. If
diplopia be not present spontaneously it must be developed ; and
it is usually possible, when the sight in the squinting eye is not too
defective, to give the patient diplopia — i.e. to make him contin-
uously conscious of the presence of the image belonging to the
squinting eye. This may be done by means of exercises with a
prism, base downwards, before the deviated eye, or by coloured
glasses, and with a candle flame used as visual object. The exer-
cises are to be repeated daily, until diplopia without a prism is
established.

Double vision having been established, we proceed to enable the
patient to fuse the double images. — i.e. to obtain binocular vision —
by exercises with the stereoscope, convenient forms of which are
Priestley Smith's heteroscope, and Worth's amblyoscope, or a modi-
fication of the latter, in which the electric illumination of the images
can be varied at will. The training of the fusion sense should be
carried out during that time of life which is the period of normal
development of this sense. After six years of age the results are
unsatisfactory, and involve great trouble and patience, yet cases
have been recorded recently in which binocular vision has been
restored i?i ])atients of 9 and 10 years of age.

As the patients are children, simple images, which require mere
superposition without recognition of the third dimension, are gener-
;illv siilliciciit at liist ; latci' on. ])ictures of geometrical drawings

CHAP. XVII.] THE ORBITAL MUSCLES. 519

involving perspective can be used. Worth, however, believes that
this treatment should be carried out by the surgeon, and that a
child old enough to carry out stereoscope exercises himself is far
past the age when the fusion sense might have been developed.
This method of treatment is useful, too, in completing the cures
which have been commenced by operative measures. But the
method makes great demands on the patience and intelligence both
of the patient and of his parents.

(c) Operative Treatment. — According to some, operative pro-
cedures should not be undertaken, unless fusion training has failed,
or is too slow and tedious, while the majority of surgeons still depend
mainly on operative treatment, with or without the aid of the orth-
optic method. Opinions differ as to the best age for operation, the
majority of surgeons preferring to wait until the patients are over
five or six years of age, while those who have studied the subject
from the orthoptic side consider, that when an operation is indi-
cated, the earlier it is done the better.

Since concomitant strabismus is the result of faulty innervation,
and not a muscular defect, rules which will ensure in every case,
with absolute certainty, the desired degree of operative effect
cannot be laid down. Indeed, all that is required in those cases in
which binocular vision can be established is an approximate correc-
tion, as the patient's fusion sense w411 complete the cure.

Formerly the operations in use consisted in tenotomy of one or
both internal recti, supplemented if need be by advancement of the
external recti. But within the past few years advancement of the
external recti has begun to take the place of tenotomy of the internal
recti, which has been almost completely abandoned by many sur-
geons. As Landolt pointed out years ago, the disadvantages of
tenotomy are serious. Tenotomy of the internal rectus by allowing
the eye to come slightly forwards and the muscle to retract, weakens
the power of convergence, and to a less degree the power of lateral
movement, without producing any increase of mobility in the op-
posite direction. Again, even when no over-correctioii of the stra-
bismus is produced by the operation, the eye after some years often
becomes divergent. Advancement of the external recti, on the other
hand, keeps the eye back in the grip of the muscles ; and, while it
increases the outward mobility, it does so without weakening the
internal recti, in fact the total range of movement is enlarged.

520 DISEASES OF THE EYE. [chap. xvii.

Furthermore there is little or no danger of over-correction, as long as
the operation is not combined with tenotomy of the internal recti.
If a double advancement should still leave a convergent strabismus
of say 15° or more, then a careful tenotomy limited to the tendon
alone, without interfering with its lateral capsular attachments, may
be performed or the muscle may be lengthened (p. 521).

Operations for Strabismus. — Tenotomy. — The instruments
required for this operation are a spring-stop speculum, a small-
toothed forceps, blunt scissors somewhat curved on the flat, and
two strabismus hooks (Fig. 209).

The eye having been thoroughly cocainised, and a few drops of
2 per cent, cocaine solution injected under the con-

rjunctiva over the site of the tendon, the patient is
placed on his back, the surgeon standing in front of
him and on his left side, if the left eye is to be operated
on, or behind him if it be the right eye. The speculum
is then applied, and the conjunctiva over the insertion
of the tendon of the internal rectus is seized with the
forceps, and incised with the scissors between the for-

tceps and the eye. Into the opening thus made the
points of the closed scissors are inserted, and, with a
snipping action, a passage is made through the sub-
conjunctival tissue, from the conjunctival opening to
Fig 209 ^^^ upper border of the tendon in case of the left eye,
or to its lower border in the right eye. The scissors
are now laid aside, but the conjunctiva is still held in the forceps ;
and, with the right hand, the point of the hook is passed
through the opening and along the passage until the edge of
the tendon is reached. The point of the hook being kept in
contact with the sclerotic, the instrument is then turned rapidly
round and under the tendon, and is brought close up to the insertion
of the latter into the sclerotic, care being taken that the whole
breadth of the tendon lies on the hook. The forceps are now laid
aside, and the hook carrying the tendon is transferred to the left
hand. One blade of the scissors (held in the right hand) is now
inserted between the globe and the tendon, and the latter is com-
pletely divided at its insertion. It is better to cut towards the
handle of the hook than away from it, as there is then no tendency
to push any fibres of the muscle off the hook. The second hook is

CHAP. XVII.] THE ORBITAL MUSCLES. 521

then employed for searching, above and below, for any strands of
the tendon which may be left undivided, the test for complete
division being that the hook can be brought up without obstruction
to the margin of the cornea. If even a small segment of the tendon
be left undivided, the result of the operation is apt to ])e unsatis-
factory. Immediately after the operation, a marked diminution
in the mobility of the eye inwards should be looked for, as this
motion can now only take place by aid of any remaining connective
tissue attachments of the muscle to the eyeball and capsule of Tenon.
If this defect in motion be not present, or to only a slight degree
in comparison with the supposed extent of operation, it may be
concluded that the tendon is imperfectly divided, and a new search
Avith the hook for undivided filaments must be made. To estimate
this loss of motion it is necessary before the operation to note the
degree of mobility of the eyeball inwards, and to compare it with
the inward motion of the other eye.

The effect of the operation may be diminished, if necessary, by
drawing the edges of the conjunctival wound together with a vsuture,

'oUlgTi

1 2

Fig, 210. — Method of lengthening a tendon (Harmau).

the tendon being thus prevented from uniting with the globe so far
back. A better way to limit the effect of a tenotomy is to pass
a suture through the tendon, as if for an advancement, and tie it
loosely so as to allow the divided tendon to retract by the desired
amount only, or to lengthen the tendon by partial incisions as

tH--

1 2

Fig. 211. — Method of lengthening a tendon combined with a vertical
displacement (Harman).

shown in Fig 210. The incisions at a and a' are limited to half
the lu'eadth of the tendon, while the intermediate incision at h
takes in two-thirds. If it be desired to produce a vertical deviation

DISEASES OF THE EYE. [chap. xvii.

as well as the horizontal effect, the incisions should be made as in
Fig. 211, whicli will allow of an upward displacement ; if a downward
displacement l)e ref|uired, the section h should ])e placed nearer
to the insertion than a.

Conjmictival sutures should also he used when an extensive
loosening of the sub-conjunctival tissue has ))een performed, in order
to prevent sinking of the caruncle or the formation of a granuloma
on the, otherwise exposed, sclera.

The 8ub-conjunctival Operation for Strabismus is performed as
follows : — A fold of conjunctiva is seized close to the lower margin
of the insertion of the muscle, and incised with blunt-pointed
scissors, so as to expose the tendon. A strabismus hook is passed
through the opening and under the tendon. The scissors are now
inserted and opened slightly, one point being kept close to the hook,
while the other is passed between the tendon and the conjunctiva,
and the tendon is divided at its insertion. This method is very
generally adopted by English surgeons, but that of von Grsefe.
previously described, is preferable, as it much more readily admits
of modifications of the effect.

In von Arlt's Method, instead of a hook being passed under the
tendon in the first instance, the latter is seized with the forceps with
which, just 2:)reviously, the conjunctiva had been raised. In other
respects the proceeding is the same as von Grsefe's, than which it
is said to be less painful.

The immediate and ultimate effects of a tenotomy are by no means
identical. Immediately after the operation the effect is marked,
owing to the loosening of the tendon from its insertion. In a few
days, when the tendon becomes re-attached, the effect diminishes,
and in the course of some w^eeks there is again an increase in the
effect, and this increase continues for about a year, as above stated.

The ultimate result may, with tolerable certainty, be estimated
immediately after the operation by testing the power of convergence.
If the patient be directed to look with both eyes at the surgeon's
finger held in the middle line, and it be approached to within 12 or
15 cm. of his nose, and if the convergence of the eyes can be main-
tained at that distance, the effect will not be too great. But if, at
a distance of from 18 to 20 cm., the operated eye should cease to
converge, or ])egin to diverge, or if even at 12 cm. the convergence,
although accomplished, cannot be maintained for more than a few

CHAP. XVII.] THE ORBITAL MUSCLES. 523

moments, and that then the operated eye deviate outwards, ultimate
divergence may be expected, even thouoh the actual position of the
visual axes be correct. A restricting- suture nuist be applied in such
cases.

Sometimes, although tlio patient converties up to 12 cm. satis-
factorily, and maintains the convergence at that distance for some
moments, the eye will then rotate inwards. In such cases there is
apt to be a recurrence of the strabismus.

Advancement. — An opening is made with scissors in the con-
junctiva immediately over the insertion of the external rectus, and
as long as the breadth of the tendon. The band of conjunctiva

Fig. 212.

between the opening and the cornea is separated up with the scissors
from the sclerotic, for to it the tendon has to be fastened later on. A
strabismus hook is now passed under the tendon, and brought well
up to its insertion, care being taken that the whole width of the
tendon is held on the hook. A needle carrying a fine silk suture is
introduced from its uj^per margin between the tendon and sclerotic,
and passed through the tendon at its middle line. In the same way
another suture is passed behind the tendon from its lower margin,
and through it, close to the first suture. Each of these sutures is
knotted firmly on the tendon, a long end being left to each suture
(Fig. 212). The tendon is separated off with the scissors from the
sclerotic close to its insertion. Tlie sutui'es are passed through the

524 DISEASES OF THE EYE. [chap. xvii.

conjunctival flap in the direction of the muscle, and are respectively
tied with their own ends. In order to obtain a better hold for the
sutures some fibres of the sclerotic parallel to the corneal margin
should be taken up on the needle, but this must be done with great
care and with strict asepsis. A greater or less effect is produced,
according as the sutures are placed farther or nearer to the insertion
of the tendon, and according as they are drawn more or less tightly.
The effect can also be increased by excision of a portion of the tendon
previous to suturing, and subsequent adhesion of the advanced
tendon can be favoured by gently scraping the sclera and under
surface of the tendon before the sutures are fastened.

There are many modifications of the advancement operation.
Some of them consist in different methods of applying the sutures.
Some operators merely make a tuck or reef in the tendon without
dividing it, others divide the tendon longitudinally and suture each
portion separately above and below the corneal margin. In capsular
advancement the muscle is advanced along with the capsule of
Tenon, the tendon being folded over on itself when the sutures are
tied. We have tried many of these methods, and find the above
described operation as reliable as any. One advantage of the
tucking operation is that if the sutures should give way the strabis-
mus will not be made worse ; but none of the methods of folding
or tucking a tendon produce as great an effect as the operation
just described.

After a tenotomy, a light dressing and bandage are applied on
the operated eye only, but in cases of advancement, even if but one
eve has been operated on, the bandage should be applied to both,
and should not be removed, except for dressing purposes, for several
days.

Dangers of the Strahismus Operation. — Severe inflammatory
reaction after a strabismus operation is very rare, and should not
occur, even after an advancement. Puncture of the sclerotic with
the scissors while the tendon was being divided has occurred in the
hands of some operators ; but except with sharp-pointed scissors,
or want of care, this cannot occur. It is also stated, that eyes have
])een lost after squint operations througli orbital cellulitis, which,
beyond doubt, must have been ])rought about- l)v the introduction
of sceptic matter upon the instruments.

Occasionally, a small artei'ial lu'anch may be (li\idcd during the

fHAP. XVII.] THE ORBITAL MUSCLES. 525

operation, and this, bleeding into the capsule of Tenon, may cause
rather alarming exophthalmos. The protrusion goes back in a few-
days with use of a pressure bandage.

Sinking of the caruncle, some months after the tenotomy, when
it does occur, can ])e remedied in the following way : — The con-
junctiva is divided vertically about 6 mm. from the caruncle. The
inner lip of the wound is raised, scissors curved on the flat passed
in, and the sub-conjunctival tissue as far as under the sunken
caruncle sej^arated. The sub-conjunctival tissue under the outer lip
of the wound, and as far as the corneal margin, is loosened in the
same way, and the two flaps are brought together with a suture,
which includes a sufficiency of conjunctiva to draw the caruncle well
forwards.

Treatment subsequent to Oferation. — It is generally necessary for
the patient to wear the correcting spectacles for his hypeimetropia
either constantly or for near vision only, according as the result of
the operative measures makes it more or less desirable to suspend
the accommodation. After some months, it is usually possible to
leave off the spectacles, except for near vision.

A cure of the strabismus, in the sense of removal of the deformity,
can be attained by operation, and by itself affords ample indication
for the operation. But a cure, in the true sense of the term, involves
restoration of binocular vision, and this is very rarely obtained by
operative measures alone. To this end the operation must be
followed up by orthoptic treatment as already described (p. 518).

Divergent Concomitant Strabismus. — This form of strabismus
is not so common as convergent squint. Two-thirds of the cases
are due to myopia, which is generally more than 5 or 6D. It also
occurs apart from myopia, and is then most frequently neuropathic.

In myopia two causes contribute to weaken the power of con-
vergence for near vision. In the first place, little or no accommoda-
tion is required, and hence a tendency exists to relax the conver-
gence. Furthermore, when the working distance is too close to
the eyes, the increased effort of convergence which is necessary can-
not always be maintained. At first the weakness of convergence
manifests itself only in near vision (insufficiency of convergence),
but later on it results in absolute divergence for distance. Myopic
divergent squint makes its appearance later in life than convergent
squint, and the fusion sense is better developed than in the latter.

520 DISEASES OF THE EYE. [cuw. xvit.

Neuropathic divergent .squint, on the other hand, is chiefly con-
genital, and the fusion sense is defective or absent. The degree of
divergence is very liable to vary from time to time in these cases.

Trcalmcnt. — The correction of the myopia, by establishing the
proper relations between accomniodation and convergence, will cure
the divergence in recent cases (see Insufficiency of Convergence,
p. 534). The glasses should be worn constantly. In other cases,
advancement of one or both internal recti should be performed, with
tenotomy of the external recti if the power of abduction be greater
than normal.

Non-paralytic divergent stral)ismus also occurs in blind eyes,
and in high myopia. In the high degrees of myopia the movements
of the eyes are more or less impaired, owing to their egg-shaped
elongation. When the vision of one eye becomes defective, or when
it becomes blind, there is always a tendency to divergence, unless
the other eye be hypermetropic. If one eye be myopic and the
other emmetropic, the myopic eye is often used for near vision, and
then the other eye diverges, whereas the emmetropic eye serves for
distance, and the myopic eye may then be divergent.

* Latent Deviations (Heterophoria).— When the orbital muscles
are in a state of normal equilibrium, or orthophoria, and the eyes
are fixing an object either distant or near, if one eye be covered^ and
thus excluded from the act of vision, it nevertheless continues to
maintain its direction, and little or no deviation of the eye takes
place ])ehind the screen, or covering hand. But if the muscular
balance be imperfect (heterophoria), there is a tendency for the
eyes to deviate from the correct position, which tendency, however,
under ordinary conditions, is kept in check by the desire for single
vision. The deviation is suppressed by a special muscular effort,
and only becomes manifest under artificial conditions ; namely,
when the vision of the two eyes is dissociated, by such measures as
render binocular vision difficult or impossible. This form of deviation
is therefore said to be latent, and is sometimes known as suppressed
squint.

Latent deviations, due to disturbance of the relation between
accommodation and convergence, occurring in errors of refraction
(such as latent convergence with hypermetropia), are not to be
regarded as heterophorias unless they persist after the optical
correction.

CHAr. xviT.] THE ORBITAL MUSCLES.

If the fusion sense become impaired — by disease of one eye,
for example — a latent deviation may become manifest and may
lead to true strabismus.

Latent deviations may be in the direction of convergence
(Esophoria), or divergence (Exophoria), or the eyes may tend to
turn in opposite directions vertically, one eye being higher than
the other (Hyperphoria), when the condition is called right or left
hyperphoria, according to the eye which is the higher.

Anaphoria (latent upward deviation of both eyes) and Kata-
phoria (latent downward deviation of both eyes) are much rarer
conditions.

The muscular effort necessary to keep the tendency to deviation
in control, sometimes leads to the development of asthenopic
symptoms (muscular asthenopia). Special attention has been paid
to this form of ' eye strain ' in the United States, where it has
been held accountable for nervous affections, such as neurasthenia,
hysteria, migraine, chorea, and epilepsy. This view, however, is
generally regarded as somewhat exaggerated. It is more probable
that heterophoria merely acts as an additional exciting cause of
nervous attacks, in those who are already subject to the conditions
mentioned. Defects in the muscular balance are not more common
in neuropathic than in healthy individuals, who do not suft'er from
asthenopia ; and these defects may be present in the former,
without giving rise to asthenopia.

Test for Latent Deviations. — The best test object for distance
(six metres) is a candle flame or frosted electric lamp, and for
near vision a black dot or line.

1. Test by Exclusion of One Eye. — While the eyes flx the test
object, one eye is covered by the surgeon's hand, and its position,
as shown for instance by the corneal reflex, is observed immediately
on withdrawing the hand, as also any movement which the eye mav
make to right itself. The latter movement indicates a deviation
in the opposite direction — e.g. if the eye move inwards on being
uncovered, it must have been deviated outwards when covered.^
Both eyes must be examined alternately. AVhen a heterophoria

1 In the ' exclusion ' test for latent deviations it will be observed that
it is the position of the eye which is covered which is noted by the surgeon,
whereas when the ' exclusion ' test is applied to detect a manifest stra-
bismus (p. 472) the uncovered eye must be watched.

r)28

DISEASES OF THE EYE.

[chap. XVII.

is present, it generally exists in both eyes, and is of the same kind.
In hyperphoria (vertical deviation), the eye which is higher will
rotate downwards, and its fellow will make a movement upwards ;
for example, in left hyperphoria the left eye will
deviate upwards when covered, and will adjust itself
by a downward movement when uncovered ; the
right eye, on the other hand, when screened will
deviate downwards, and will rotate upwai'ds on re-
^ exposure. This test, however, is by no means so

I delicate as the following subjective tests, which de-

I pend on the production of diplopia.

I 2. Tests with Prisms.— {a) This test

was first used by von Graefe for the ex-
amination of insufficiency of the internal
Fig. 213. recti. A prism is placed vertically before
one eye, of such a strength that it cannot
be overcome by the muscles ; one of 10° is sufficient.
A dot with a fine line drawn veitically through it (Fig.
213) on a sheet of white paper is given to the patient
to look at, at his usual reading distance. If the prism
be placed with its base downwards before the right eye,
this, in the normal condition, both eyes fixing,
would produce a double image of the dot and line,
placed of course vertically, one over the other,
and as the images of the lines overlap, the figure
would seem to be a line with two dots, the upper
dot being the image belonging to the right eye
(Fig. 214). In insufficiency of convergence (ex- fjg. 215.
ophoria), the image of the right eye would not
only be higher than that of the left, but it would also stand
to the left (crossed double images) more or less ; so that
here the picture is that of two lines, each with a dot, the
upper line and dot standing to the left side (Fig. 215). This
crossed diplopia indicates divergence. In this case the
artificially produced vertical diplopia renders the latent de-
viation manifest, and a lateral diplopia is superadded.

In order to test for vertical deviations (hyperphoria), the
prisms must be placed liorizontally, and with their bases inwards ;
because the external being much weaker than the internal recti,

Fig.
214.

f'HAP. XVTT.

T?IE OnniTAL MUSCLES.

520

prisuis of low er degrees can be used ; but for this purpose the rod
test described below is better.

(b) Stevens' phorometer (Fig. 216) is a convenient instrument
for applying the prism tests. The prisms can be placed either

Fig. 216. — The prisms of Stevens' phorometer.

vertically or horizontally by the lever, and the degree of hetero-
phoria can be measured by a rotation of the prisms, the amount
of the deviation being indicated on the scales to the right and left,
(c) Maddox's Double Prism is also useful. It is composed of
two prisms, base to base, and is easily adjusted. When placed

Fig. 217.

vertically before, say, the right eye, with the line of junction of
the prisms opposite the pupil, this eye sees two images of the spot,
one vertically over the other, and, if the muscular equilibrium be
normal, the spot seen by the left eye will appear to be in a line with
34

-)30

Dr. LEASES OF THE EYE.

{CUXV. XVTT.

the other two. and midway between them (Fig. 217). If a hori-
zontal line be used as the test object, the different forms of hetero-

phoria

can

dia

gnosed

by
R

the position of the central

Inie seen
-R

Fio. 21S.— \<

Fto. 21!).- — Ki<2;lit hypcrijlioria and
osoplK>rin.

l)y the left eye, with reference to the two lines seen ))y the rioht —
e.g., Fig. 218 indicates normal e(|uilii)rium, and Fig. 219 right hyper-
phoria and esophoria.

3. Maddox's Rod Test.— This is probably the ])est test. The
apparent lengthening of a flame into a
line of light, when looked at through a
strong cylinder, is utilised to make
the two images so dissimilar, that no
desire to unite them remains. The
chief advantage of this principle is
that slight malpositions do not, as
with prisms, vitiate the result mate-
rially. The instrument consists of a
number of parallel glass rods (Fig. 220)
usually coloured red, which thus pro-
at right angles to the axis of the rods.

Fig. 220.— Maddox's Rods.

duce a red line of lisht,

when 2)laced [before one of the eyes, the other eye seeing the

Fio. 221. — 1. Orthoplioiia. 2. Exophoria or latent divergence.
.'J. Esoi)horia or latent convergence.

light or flame naturally. When the red line passes through the flame
there is orthophoria (Fig. 2lM . 1).

riTAP. xvTT.l THE ORBITAL ^r^'SrLES. .-»31

The line of light iiiu.st be vertical, and tlierelore the rods must be
placed horizontally for horizontal deviations (Fig. 221), and the
opposite way lor vcitical deviations (Fig. 222). The defect is
measured by the deviating angle of that prism, which brings the
light and line together, or, preferably, by a tangent scale, placed
with its zero just behind the flame, so that the figure crossed by
the line of light gives the deviation in degrees. For vertical diplopia
the scale should be vertical, and for horizontal diplopia, horizontal.
In either case the axis of the cylinder should be parallel to the scale.
When the cylinder is vertical, it should be shaded from the light of
the window. By placing the patient's head in different positions,
the diplopia can be measured in all parts of the oculo-motor field.
Maddox's vertical and horizontal scales should, for this purpose,
be fixed on the wall, with the flame or electric lamp at the zero
point. This test is most useful for distant vision (6 metres).

Fig. 222. — 1. Orthophoria. 2. Left hyperphoria. 3. Right hyperphoria.

4. Maddox's Wing Test. — This is a very simple and useful test
for measuring horizontal, vertical, and cyclophoric deviations with-
out prisms at reading distance. The patient looks through the slits
in the eye-pieces at E (Fig. 223). The horizontal wing R covers the
upper half of the field of the right eye, and the wing L the lower
half of the left field, so that the right eye sees the arrow on the plate
S, while the left eye sees the scale towards which the arrow points.
For vertical deviations a vertical scale with a horizontal arrow is
used, and the pillar P is rotated so that the wings are turned longi-
tudinally, out of the way, and the median vertical screen then
blocks out the arrow from one eye and the figures from the other.
If vision be defective in one eye a movable metal arrow is provided
which can be moved along the upper part of the screen until it
appears to the patient to be pointing at the white arrow, the number

-)32 DISEASES OF THE EYE. [chap. xvii.

or letter on the scale to wliicli the metal arrow points can then be
read off. We have found this a very useful and simple instrument.
In order to obtain accurate results when testing the muscular
balance, any error of refraction must be corrected.

Fig. 22.3. — Maddox's Wing Test for Heterophoria.

* Symptoms oj Heterophoria. — Great difference of opinion exists
as to the frequency with which heterophoria gives rise to asthenopia.
In the United States it is said to be very common. There is no doubt
that heterophoria may be present without causing any incon-
venience. Hyperphoria is the most troublesome form, esophoria the
next most troublesome, while exophoria,unlesscombined with a dimin-
ished amplitude of convergence, causes little or no annoyance. The
symptoms are : headache and pains in the eyes — especially towards
the end of the day, or following on long-continued close observation
— giddiness and conjunctival hyperemia. Narrowing of the pal-
pebral fissure sometimes occurs in hyperphoria, in the eye which
deviates upwards.

Treatment. — This will depend, not merely on the degree of the
heterophoria, but also on the strength of the muscles, as measured
by their power of overcoming the diplopia produced by prisms.
Whether the heterophoria be present in near, or in distant vision,
or in both must also be considered. In near vision at a distance of

CHAP. XVII.] THE ORBITAL MUSCLES. 533

12" an exophoria of 2° to 4° is very common, and often causes no
annoyance.

The treatment consists in the wearing of prisms with the base
in the direction of the muscle to be relieved (p. 400), exercises with
prisms, or operation. The first two will suffice in moderate degrees
of the defect ; but it may be mentioned that the value of exercises
with prisms is doubted by some surgeons. When only a prism of
low degree is required, the desired effect may be accomplished l)y
decentration of the lenses (p. 412), which correct the error of re-
fraction, if there be one. In the higher degrees operation may be
necessary, advancement of a muscle being preferred to tenotomy of
the antagonist. In Europe, graduated tenotomies, by which is
meant partial division of the fibres of the tendon, are not regarded
with favour.

Cyclophoria {Latent Torsion). — This consists in a tendency to abnormal
rotation round the antero-posterior axis of the eyeball, so that the vertical
meridians of the eyes are no longer parallel. The subject is not, as yet,
well understood. A certain amount of torsion appears to occur physio-
logically in near vision. Latent torsion can be detected with the double
prism, a horizontal line being vised as the test object. If it be present, the
line seen by the naked eye, between the double image, will not be parallel
to the double lines seen by the eye clad with
the prism. Fig. 224 indicates an inclination of
the upper ends of the vertical meridians
towards one another. The opposite is, how-
ever, the more common condition. Maddox's
rod and Stevens' clinoscope are also used for Fig, 224.

testing cyclophoria.

Maddox's wing test (Fig. 223) provides a very simple means of detecting
and measuring cyclophoria. The wings are arranged as when testing for
vertical deviations, but the test object consists of a card with a printed
line seen only by one eye and an elastic movable thread, parallel to the
printed one, seen only by the other eye ; if the lines do not appear to the
patient to be parallel, he is required to move the upper end of the elastic
thread until it appears to be parallel to the fixed line, and the degree of
inclination of the thread can be read off on a millimetre scale at the edge
of the card. The deviation of the eye is in the same direction as the
inclination of the thread.

According to Savage, in astigmatism witli i:>bliqvie axes, torsion is
necessary to make the vertical meridians coincide with the nearest meridian
of the astigmatism ; and he believ^es that this accounts for the fact, that
some astigmatic people are more comfortable without correction of their
astigmatism, being unable to abandon the torsion to which they had
become habituated.

534 DISEASES OF THE EYE. [chap. xvii.

Insufficiency of Convergence. — This has to a great extent been con-
fused with exophoria (latent divergence) for near vision ; indeed, von
Grsefe's test is really one for exophoria or esophoria existing in near
vision, rather than for insufhciency of convergence. The two con-
ditions may co-exist, but one does not involve the other. Either
may be present alone ; furthermore, a latent convergence (esophoria)
may in some cases exist along with insufficiency of convergence.
The essential point in the diagnosis of the latter condition is the
presence of a diminution of the amplitude of 'convergence (p. 9)
as measured by gradually approaching to the eyes, in the median
line, a series of parallel fine lines, or an illuminated line or point,
until one eye is seen to diverge, or until the patient gets crossed
diplopia. The test should be made on several different occasions,
as results are liable to vary with the state of health or available
energy of the patient.

Causes. — Insufficiency of convergence usually depends on de-
fective innervation, due to a central cause, which may be organic,
as in locomotor ataxy, or more commonly functional, as in hysteria,
neurasthenia, anaemia, and exophthalmic goitre (partly). Other
causes are myopia (see Divergent Strabismus, p. 525), and perhaps
sometimes anatomical defects in the internal recti.

Symptoms. — Patients complain of pains in the head and _eyes,
and fatigue after reading, sewing, etc., for any length of time ; they
are inclined to hold the book or work farther from them, and they
sometimes get relief by closing one eye.

Treatment. — In neuropathic and debilitated patients, the general
health requires attention both mentally and physically, and out-of-
door exercise, with peace of mind, should be recommended. With
regard to local treatment, exercises in convergence, with or without
the aid of the stereoscope, should first be tried, any error of refrac-
tion being of course corrected. A full correction of myopia, and
an under-correction of hypermetropia may render assistance, by
making demands on the accommodation, and thus indirectly on
the convergence. If exercises prove useless, prisms with bases
inwards may give relief, or, if glasses be worn, they can be decentred
(p. 412).

Should these methods prove unsuccessful, advancement of one
internal rectus, or of both if necessary, should be performed.

Spasm of the orbital muscles only occurs in convulsions, in con-

CHAP. XVII.]

THE ORBITAL MUSCLES.

535

jugate deviations, and in hysteria. In the latter condition it is not
uncommon to find spasm of the orbicularis, witli convergent strabis-
mus and contraction of tlie pupil due to spasm of accommodation.

Two very simple and useful instruments which have of late been
applied to the observation of phenomena connected with binocular vision,

___-,-0 R

■^L

Fia. 225. — To illustrate the principle of the Diploscope.

including the detection of malingerers, are the Diploscope of Remy, and
Harman's Diaphragm Test. These tests have the advantage over the
stereoscope of being made under more natural conditions. We have found
the instruments of great service in ascertaining the binocular effect of
the reading-glasses ordered for presbyopia, etc.

The Diploscope consists of a screen with perforations through which
test letters are seen. The holes may vary in number and position. In the
simplest form of the test there are two holes placed horizontally through
which a horizontal row of three or four letters is visible. Fig. 225

_-..0 R

'-0 L

Fig. 22(5. — To illustrate the principle of the Diaphragm Test.

explains the principle involved. The letters on the test card T are seen
through the two apertures in the screen D in such a way that the consonants
only are visible to tlie right eye R, and the vowels to the left eye L. In
normal vision the letters appear in their proper j^osition as K O L A ;
but if the eyes diverge, the resulting crossed diplopia will cause K L and
O A to move away from each other so that the test will now read K L O A.
Excess of convergence on the other hand ^\•ill make the pairs of letters

536 DISEASES OF THE EYE. [chap. xvii.

approach each other so as to read O K A L, or in higher degrees O A K L.
If there be a vertical deviation of one eye, one pair of letters will appear
to be higher than the other.

In Harman's test, Fig. 226, the Screen D has only one aperture,
through which the central portion of the test on the card T will be visible
to both eyes, and the other portions to one ej^e only ; for instance, No. 3
is seen by both eyes, 1 and 2 by the right eye (R) only, and 4 and 5 by the
left eye (L) only. It is found tliat, in order to obtain binocular vision,
some persons require a larger area visible to both ej^es than do others.
According to Harman, the wddth of this area measures the intensity of
the desire for binocular vision, and he has called it the ' ocular poise.'
The size of the area common to both eyes depends on the width of the
aperture, and in the newer model of the instrument this can be varied,
and its measurement can be read off on a scale.

Nystagmus.

By the term nystagmus (vuo-ray/xdj-, nodding of the head) is
meant an oscillation, or short to and fro movement, of the eyes,
which, except in rare cases, is involuntary. The oscillations may be
horizontal (the most common form), vertical, rotatory, or, if mixed,
may be circumductory. The movements of the eyes are almost
always concomitant, and usually constant, but they may increase
or become visible in certain positions of the eyes and diminish
or cease in others. They are sometimes accompanied by oscil-
lations of the head. Nystagmus usually affects both eyes, but in
rare cases it may be unilateral. The oscillation disappears during
sleep. There are two essentially different types of nystagmus : —
The TJndulatory form in which the movements are equal in velocity
and range on each side of an imaginary point, and the Rhythmic,
jerky, or spring-like form, in which a relatively slow movement in
one direction is followed by a more rapid movement in the opposite
direction. Although the slow component is the primary one, the
direction of the nystagmus is named according to the rapid phase
which is more readily noticed. A very good example of this form
of nystagmus occurs under physiological conditions, in the case of a
person watching objects from the window of a railway carriage
in rapid motion, where the slower movement of the eyes follows
the passing object, while the quick return is in the direction in
which the train is travelling.

Nystagmus, whether it be congenital or acquired, is not a primary
affection, but is rather a» indication of disease in the eye itself.

CHAP. XVII.] THE ORBITAL MUSCLES. 537

in the vestibular apparatus, or in the central nervous system.
According to some, undulatory nystagmus is more liable to be
associated with purely ocular defects. But there is no doubt
that the nystagmus which owes its origin to vestibular or nervous
diseases is of the rhythmic type. Patients in whom nystagmus is
due to a congenital defect of vision, or whose sight becomes affected
in early life, do not complain of anyfapparent movement of visual
objects ; but those who become affected with it in later life {e.g.
coal-miners) are much troubled by that symptom, especially at the
onset.

1. Amblyopic or Ocular Ni/staytnus. — When a child is born ^Aitli
defective vision, or when the defect occurs within the first few years
of life, the cerebral control over the co-ordinating centres for eye-
movements, which depends on accurate fixation by the macula
lutea, is in abeyance ; the co-ordinating centres are then thrown
out of gear by numerous other reflexes and the regular tonic con-
tractions of the ocular muscles are replaced by irregular involuntary
clonic contractions (incomplete tetanus).

Amongst the ocular diseases and defects, congenital and acquired,
which cause nystagmus may be mentioned opacities of the lens
and cornea (leucomata following ophthalmia neonatorum is one of
the commonest causes), congenital colobomata, astigmatism with
amblyopia, albinism, chorioido -retinal and macular diseases, retinitis
pigmentosa, and total colour blindness. Nystagmus associated with
albinism and opacities of the media is increased by exposure to
strong light, while in retinal affections the oscillations are greater
in the dark. Conjugate deviations are often present in congenital
nystagmus.

2. Coal-Miners'' Nystagmus. — This is a form of nystagmus which
affects coal-getters, more especially those who have worked in the
mines for a number of years. It is believed by most to be due to the
long-continued, imperfect fixation caused by defective illumination,
and is undoubtedly more common in mines where protected lights
are used, than in those in which naked lights are employed and the
light therefore is better. The oscillations of the eyes are rarely
unilateral : they are purely undulatory, most frequently rotatory,
and are increased or brought on by looking up, while they diminish
or cease on looking down. The patients are conscious of an apparent
movement of the visual fields, which causes headache and giddiness.

538 DISEASES OF THE EYE. [chap. xvii.

Tremor of the head and eyelids with blepharospasm, intolerance
of light, and mental depression are often present. Strain of the
ocular muscles, nervous exhaustion, heterophoria, and errors of
refraction have also been advanced as possible associated causes of
miner's nystagmus.

3. Vestibular Nystagmus. — The semicircular canals and vestibule
constitute one of the chief peripheral sources from which reflex impres-
sions act on the co-ordinating centres in the pons and thereby affect the
inuscular tonus of the opposite side of the body, including the muscles
concerned in associated movements of the eyes. The movement of the
endolymph, caused under normal conditions by alterations in the position
of the head, provides the stimuli which gives rise to these reflexes. In the
case of the horizontal canals the stimulus is greater when the movement
of the endolymph is from the canal towards the ampulla than when
it is ampullofugal, while in the vertical canals the effect is the reverse.
The eyes move in the plane of the affected canal and in the same direction
as the lymph movement. In the case of the external or horizontal canals
therefore the eyes will move laterally — in other words, there will be a
conjugate deviation to the side opposite to the stimulated labyrinth. The
cerebral control over the co-ordinating centres then tends to correct this
deviation by a quicker movement in the opposite direction, thus causing
a rhythmic nystagmus which, since the direction of the nystagmus is
named according to the rapid phase, will be to the same side as the
labyrinth stimulated. The slow phase is the primary and direct result
of the vestibular stimulus, and this is proved by the facts, amongst others,
that stimulation of the vestibule in an unconscious person gives^ rise
to the slow movement only, and that the nystagmus diminishes on looking
towards the side of the slow component.

Vestibular nystagmus may be induced for experimental or diagnostic pur-
poses, or it may arise spontaneously iroin disease of the vestibular apparatus
or of its connections.

Nystagmus can be induced by rotation of the patient, by syringing
the ear with hot or cold water (caloric test), by galvanic stimulation, or
by pressure in cases of fistula of the vestibule. It will suffice in a work
such as this to give a simple example. In the rotation test the particu.lar
canal affected will depend on the position of the patient.

If the patient be seated M'ith head erect or rather tilted at an angle of
30° forward, the horizontal semicircvilar canals will alone be affected by
horizontal rotation of the body. Fig. 227 explains the course of events
when the patient is rotated say from right to left, as indicated by arrow 1 .
Diiring the rotation the endolymph in the canals, owing to inertia, tends to
flow in the direction of the arrows 2 and 2', i.e. towards the ampulla in
the left labyrinth (+), wliich becomes thereby stimulated in excess and
cuses a slow movement of the eyes to the opposite side in the direction of
arrow 3. The quick phase or nystagmus will therefore be in the direction
of arrow 4 — that is, in the same direction as the rotation. On the other
hand, when the rotation is stopped the lymph current will be reversed

CHAP. XVII.

THE ORBITAL MUSCLES.

539

and the post-nystagmus, as it is called, which is easier to observe, will
now be in the opposite direction to that in which the patient was rotated.
This test is used to compare tlie conditions of the two labyrinths. The
caloric test, however, is more easily applied, and has the advantage of
confining the stimulus to one labyrinth ; it is carried out by syringing
the ear with warm or cold water. In this test the canal under investigation
must be vertical. Syringing with hot water, except the patient be in-
verted, has the same effect as increased stimulation and produces nystag-
mus to the same side, whereas with cold water the nystagmus is contra-
lateral.

Froni

Left

Right

Back

Fig. 227. — Illustrates Nystagmus on Rotation of the Body to the left.
The letters A A are opposite the ampullae of the right and left hori-
zontal canals.

The arrows indicate : — 1. Direction of rotation of patient.

2. ,, ,, endo lymph current.

3. ,, ,, the slow ocular movements.
The wavy arrow 4, and the eyes above it, show the direction of the rapid
phase (nystagmus) of the eye movements.

In this case the left labyrinth marked + is subjected to the stronger
stimulus.

Stimulation of the vertical canals is followed by a rotatory nystagmus,
which is not uncommonly accompanied by navisea and vomiting. In
vestibular nystagmus an apparent movement of the visual fields is seen
during the slow phases.

Spontaneous nystagmus may be caused by disease of the vestibular
apparatus, either peripheral (vestibule, or vestibular nerve) or central
(vestibular nuclei, centre of co-ordination, posterior longitudinal bands,
or fibres of connection with cerebral cortex). In disease of tlie labyrinth
itself the symptoms, as a rule, are the same as those whicli follow a
destructive lesion, and the nystagmus, which is of a mixed character,
is towards the sound side.

4. Nystagmus in Diseases of the Nervous Sijstein. — The nystagmus
wliicli occurs in disease of the nervous system is mostly vestibular

540 DISEASES OF THE EYE. [chap. xvii.

in character and is probably in most cases due to involvement of
the vestibular nuclei, cerebellum, or fibres of association. The
cerebellum acts as a regulator of reflex impressions, and sends corre-
sponding impulses to the oculo -motor centres and to the muscles
concerned in maintaining equilibrium, and interference with its
functions thus indirectly causes nystagmus. Cerebellar tumours
or abscesses often give rise to a coarse nystagmus towards the side
of the lesion and a fine quick nystagmus to the opposite side.
Nystagmus is especially liable to occur in lesions situated towards
the dorsal portion of the pons and medulla extending from the
level of the vestibular nuclei below to the corpora quadrigemina
above, and in cases accompanied by subtentorial increase of pressure.

In Disseminated Sclerosis the nystagmus is nearly always hori-
zontal, and may only be detected in extreme lateral movements of
the eyes in the early stage. In such a case it may be difficult to
distinguish a true nystagmus from the nystagmoid movements
which are sometimes seen in these positions in normal individuals,
or which are met with in cases of paresis of the ocular muscles.
Indeed some authors regard this form of slight nystagmus in dis-
seminated sclerosis as an indication of slight conjugate paralysis.

Other diseases in which nystagmus is a symptom are : Fried-
rich's disease, Heredo-cerebeJlar Ataxy, Syringomyelia, Ataxic Para-
plegia, severe Multiple Neuritis, Hysteria, and intracranial injuiies.

5. Rare Varieties of Nystagmus are Voluntary Nystagmus, Here-
ditary N., Spasmus Nutans, Myoclonic N., and Latent N. which
appears only on suppression of binocular vision by excluding one
eye.

Treatment. — Congenital nystagmus is, as a rule, incurable, but
in cases which admit of improvement of vision, a cure, partial or
complete, is sometimes brought about when the vision improves.
If stiabismus be present, it should be cured, after which a diminu-
tion in the oscillations may result. In miner's nystagmus, the all-
important measure is a permanent relinquishment of mine work ;
and this is frequently followed by satisfactory results.

CHAPTER XVIII

DISEASES OF THE EYELIDS

Erythema, erysipelas, phlegmonous inflammation, and abscess are
all liable to attack the eyelids, but require no special observations
in this work. It should merely be stated that erysipelas of the eye-
lids may extend to the connective tissue of the orbit and ultimately
give rise to atrophy of the optic nerve.

Eczema. — This is often seen on the skin of the eyelids, most
frequently in connection either with general eczema of the face or
with phlyctenular ophthalmia. The lacrimation in phlyctenular
ophthalmia increases the eczema, which then, by causing contrac-
tion of the skin of the lower lid, often produces eversion of the
inferior punctum lacrimale, and this, in turn, causes increased lacri-
mation.

Atropine infiltration of the eyelid, from use of atropine eye-drops
in some persons, is frequently accompanied by a moist form of
eczema of the lids and face.

Treatment. — Should the use of atropine be the cause it is, neces-
sary to discontinue it, and to substitute solution of Scopolamine
(gr. j and 3]). As an opplication to the affected skin the following
ointment is useful : — Oil of Cade, Viy iv, Zinci oxidi, gr. v. Adipis
lanse hyd. vaselin alb., aa. 51J.

(Edema of the eyelids may be due to general causes such as
nephritis or cardiac disease, when it is usually bilateral and non-
inflammatory. It is more common, however, to find the oedema
on one side only, and in such cases it is attended with more or less
hypersemia of the skin of the eyelids, and is the result of a local
inflammation in the eyelids themselves (hordeolum, abscess, chancre)
or of septic inflammation in the eye, lacrimal sac, orbit or nasal
sinuses. In Thrombosis of the Cavernous Sinus the oedema is often
bilateral and exophthalmos is present as well. When an inflammatory
oedema is limited to one eyelid, it is generally the upper lid which

541

542 DISEASES OF THE EYE. [ckav. xvttt.

is the affected one. Marginal oedema of the upper lid is a frequent
occurrence in septic iritis, whether it be metastatic or follow an injury
or operation. In old people even after a cataract operation which
progresses normally, the mere pressure of the bandage may cause an
oedema of the upper lid, which is usually most marked above the
inner canthus. Again oedema of the upper lid may be the first
sign of disease of the frontal sinus, and hordeola are particularly
liable to cause oedema if they be situated at the inner or outer canthus.
Amongst other causes may be mentioned stings or bites of insects
and foreign bodies under the upper lid, and it should not be forgotten
that Iodide of Potassium may produce it.

Angio-neurotic oedema of the eyelids is a peculiar non-inflamma-
tory form of transient and recurring oedema, met with chiefly in

Fig. 228.

young females who sometimes develop oedema of a similar kind in
other parts of the body. CEdematous eyelids pit on pressure and
can easily be distinguished from the swollen lids in myxoedema,
solid oedema (Fig. 228), and ptosis adiposa. In emphyssema, too,
the peculiar sensation communicated to the fingers on palpation
will prevent its being mistaken for oedema.

The condition known as Solid CEdema, Elephantiasis Lymphan-
gioides, or Elephantiasis Nostras of the Eyelids, is well represented in the
accompanying picture (Fig. 228) of a case under the care of Sir A. Critchett.
It is a chronic tumefaction of the eyelids. The skin covering the swelling
is smooth and pale, and resembles the skin of an oedematous lid ; but on

CHAP. xvTTT.] THE EYELrnS. r>43

palpation the swelling is found to be more resistant than simple csdema.
There is, almost invariably, a liistory of recurring attacks of facial erysipelas.
These give rise to a permanent alteration of the lymph channels, and,
each attack leaving its trace, an ever-increasing hypertrophy of the
tissues of the eyelids takes place.

Treatment. — Operative measures have been adopted in many instances
with satisfactory results, both cosmetically and as regards the functions
of the eyelids ; but, imfortunately, in those cases which have remained
under observation sufficiently long, the former condition gradually
returned, as in Sir A. Critchett's case (Fig. 228), in tlio picture of whicli
the cicatrices of the operations can be seen. Multiple punctures, collodion,
pressure, etc., and many internal remedies have been tried in vain.
Drainage by the insertion of subcutaneous threads after tlie method of
Hanley has proved of service, and is worthy of trial.

Marginal Blepharitis {(SXecfiapov, eyelid), or Ophthalmia Tarsi,
is nothing else than eczema of the margin of the eyelid. It is found
either as Blepharitis Ulcerosa (Eczema Pustulosa), or as Blepharitis

Squamosa (Eczema Squamosa). In blepharitis ulcerosa, small
pustules form at the roots of the eye lashes, and these, having lost
their covering, become ulcers, which scab over. The \vhole margin
of the licl may then be covered with one large scab, in which the
eyelashes are matted, and under which the lid will be found swollen,
red, and moist, with many minute ulcers and pustules, the latter
due to suppuration of the hair follicles and of the sebaceous glands
belonging to them. Many eyelashes come away with the scab
when removed, and others are found loose and ready to fall out.
Cicatrices resulting from the suppuration are also present, and there
the hair follicles are destroyed, and the cilia do not grow again.

The disease is chronic, and is most commonly seen in strumous
children. It is frequently accompanied by phlyctenular ophthalmia,
or by simple conjunctivitis, which may have been its cause, or which
promotes it by keeping the margin of the lid constantly wet.

Blepharitis is sometimes associated with lacrimal obstruction
and the cliplobacillus is responsible for the disease in some cases,
more especially in angular blepharitis.

If neglected, ulcerous Ijlepharitis, by reason of the scars it pro-
duces, is liable to give rise not only to peimanent loss of eyelashes,
but to irregular growth (trichiasis) of those which remain. After
a time, the continued congestion and inflammatory swelling of the
lid margin leads to its hypertrophy, chiefly of the upper lid.

The margin of the lower lid is liable to become everted, owing

■)44 DISEASES OF THE EYE. [chap, xvitt.

to contraction of the skin of the evelicl. Involved in this eversion
is the lower punctum lacrimale, and consequently lacrimation
ensues, with resulting- eczema of the eyelid, which in turn promotes
the ectropion, while the exposure of the conjunctiva of the lower
lid increases the already existing conjunctivitis.

The Treatment of Ulcerous Blepharitis consists, in the first place,
in the careful removal of the scahs. without causing any bleeding
of the delicate surface underneath. Bleeding indicates that newly
formed epithelium has been torn away, and it is important, there-
fore, to soften the scabs by soaking the eyelid with olive oil, or with
a warm saturated solution of bicarbonate of soda, before removing
them. Any pustules found under the scab should be punctured,
and all loose eyelashes, which act as foreign bodies, taken away.
Also all diseased eyelashes should be drawn away. These are
recognised by aid of a magnifying glass as shorter, thicker, straighter.
and more highly pigmented than the normal ciliae ; and when re-
moved their roots are found to be club-shaped. The ulcers should
be carefully touched twice a week with a fine point of solid mitigated
lapis. The surface should then be well dried by pressure, not by
rubbing, with cotton wool, and the following ointment rubbed in
with a glass rod — Hydrarg. pracip. alb. gr. vj, Zinci oxidi gr. viij,
Liq. plumbi subacet. n\ vj, Adipis benzoat. ad. 3iv. This ointment
is to be continued by the patient, night and morning, after the lids
have been w^ashed, and all scabs and loose eyelashes removed
from them, and well dried, until healing is thoroughly established.
In many mild cases a boric acid ointment (gr. ij ad 3j of vaseline
or of lanolin) will be found efficacious instead of the above. A
creolin ointment suits many cases, if it do not irritate — viz. Creolin,
1 to 5 min. ; Aq., 3ij ; Lanolin, 5vj.

Or, again, after the scabs and loose and diseased eyelashes have
been removed as above, the margins of the eyelids may be freely
bathed with a wash of ten to twenty minims of creolin to eight
ounces of water, and after this the creolin ointment may be applied.
A first principle of treatment in all these cases is that it be non-
irritating. If caused by the diplobacillus preparations of zinc are
indicated. Noviform in 5 to 20 per cent, ointment has been much
recommended of late.

All complications with conjunctival affections or lacrimal ob-
struction must be attended to, the patient's general system carefully

PHAP. XV 1 1 1.] THE EYELIDS.

improved, and oiiors of relraetiuii eoirected. lu inveterate cases,
the use of staphylococcus vaccine is indicated.

Squamous Blepharitis comes on after the ulcerous form has
passed away ; or, it is found as a primary affection, especially in
chlorotic women. The margin of the lid is somewhat swollen and
red, and covered with loose epidermic scales. It is an extremely
chronic affection, but, although disfiguring, it has no dangerous
sequelye.

The Treatment of Squamous Blepharitis. Boric acid ointment
(gr. XX ad. 5j).

Chlorosis, if present, should be treated with suitable remedies.

Phtheiriasis {<iiOup, a louse) Ciliorum. — The pediculus pubis
occurs on the eyelashes. It gives rise to excessive itching and burn-
ing sensations, and the consequent rubbing produces excoriations
of the margin of the lid. The lice occupy chiefly the roots of the
eyelashes, to which they cling tenaciously, while the shafts of the
cilia are covered with their brown egg-capsules ; and this gives
to the cilia the peculiar appearance of being covered with dark
brown powder, which enables the diagnosis to be easily made. The
fully developed parasites, as well as the eggs, may be more readily
seen by aid of a strong convex glass.

Treatmentt. — With a cilium forceps the pediculi as well as some of
the eggs may be removed from the cilia. This proceeding repeated
daily, along with the application of mercurial ointment, or of a weak
red precipitate ointment, to the margin of the eyelids morning and
evening, will soon effect a cure.

Hordeolum {hordeum, a grain of barley), or Stye, is a circum-
scribed purulent inflammation situated at the fallicle of an eyelash.
It commences as a hard swelling, with more or less tumefaction
and oedema of the general surface of the lid, and often with some
chemosis, especially if it be situated at the outer canthus. In its
early stages there is much pain associated with it. It gradually
suppurates, and may then be punctured or allowed to open of
itself.

Styes frequently come in rapid succession, and then, probably
a constitutional disturbance exists as the cause. In the earliest
stage cold applications may be successful in putting back a stye, but,
later on, warm stupes will hasten the suppuration and relieve the
pain. Habitual constipation is a common source of hordeolum,
35

540 DISEASES OF THE EYE. [chap, xviii.

and should be met by the use of mild laxatives. Sulphide of cal-
cium, -^^J gr. every hour, or I gr. twice a day, for an adult, has been
recommended as a specitic in these cases. If there be troublesome
recurrences, staphylococcic vaccine treatment can be adopted.

Chalazion (xaka^a, hail), Meibomian Cyst, or Tarsal Cyst, is
probably a granuloma in connection with a Meibomian gland, and
not a mere retention cyst. The glanuloma consists of round and
epithelioid cells and sometimes giant cells. Chalazion has its origin
in a slight chronic inflammatory process in the connective tissue
surrounding the gland, which usually passes off without having
attracted the attention of the patient, but occasionally, when the
cyst has developed, acute inflammation with formation of pus comes
on. The tumours vary in size from that of a hemp-seed to that of
a hazel-nut, causing a marked and very hard swelling in the
lid without any redness of the latter. They may last for
several months. Occasionally they open spontaneously on the
conjunctival surface, giving exit to contents which are usually viscid
or grumous, and sometimes purulent, and subsequently a reddish
granulation forms, which becomes more or less flattened against the
eyeball by the pressure of lid.

Treatment. — No application can bring about absorption of these
tumours. Local anaesthesia having been produced by an acoine,
or by a cocaine and adrenaline injection, the lid is everted, and the
tumour is opened by an incision from the conjunctival surface, and
its contents thoroughly evacuated by aid of a small curette. The
operation is greatly facilitated by the use of a chalazion clamp
forceps, which render^; the tumour more prominent and checks
haemorrhage. Difficulty is sometimes experienced in finding the
point in the conjunctiva corresponding wdth the tumour, but it is
usually indicated by a dusky or greyish discoloration. Immedi-
ately after the evacuation, bleeding into the sac often takes place,
and causes the tumour to remain for a day or two as large as before
— a fact of which the patient should be warned. The operation
may occasionally require to be repeated. The interior of the sac
should not be touched with nitrate of silver ; and the incision and
evacuation should not be made through the skin, unless in rare
instances when the capsule is exceptionally thick, as more or less
disfigurement from the scar many result.

More than one chalazion is often present at a time, and some

CHAP. XVIII.

THE EYELIDS. 547

people become litibte to them periodically during a, number of years,
especially those who sutler from acne of the face.

'^^ Milium {miliiun, a millet seed) presents the a2)pej)rancc of a
perfectly white tumour, not much larger than the head of a pin,
in the skin of the eyelid. It is a retention tumour of a sebaceous
gland, and can readily be removed 1)y puncture and evacuation.

* Molluscum, or Molluscum Contagiosum.— This is a white
tumour in the skin of the eyelid, which may attain the size of a
pea. At its summit is a depression, which leads to an opening into
the tumour, through which the contents can be pressed out. It is
probably a diseased condition of a sebaceous gland, and contains
altered epithelial cells, and peculiar bodies, termed molluscum cor-
puscles, which are of a fatty nature. Many such tumours may
form in the lids at the same time. It is held by some observers
that this affection is contagious, although in what way is not clear,
inasmuch as experimental rubbing of the contents of a molluscum
into the skin has not given rise to the tumours.

Treatment. — Each separate tumour must be evacuated by
simple pressure, or after it has been opened up with a knife or scissors.
Teleangiectic Tumours, or Naevi, of the eyelids occur congenitally.
Treatment. — Small tumours of this kind may be destroyed by
touching with nitrate of silver or hydrochloric acid, or by performing
vaccination on them in the case of infants, instead of on the arm.
Larger tumours may be ligatured or treated with the galvano-
cautery, or with ethylate of soda, or carbonic acid snow, and elec-
trolysis is a very effectual method in many cases.

* Xanthelasma (far^o?, yellow] (Xaafxn, a layer) is the term
applied to yellowish plaques raised slightly over the surface of the
skin of the eyelid, with very defined margins. Women are more
liable to it than men. The patches are generally bilateral and sym-
metrical, and are most frequently situated in the neighbourhood of
the inner canthus. The shape of these plaques is extremely irregular,
and they may attain the size of a shilling or larger. The appearance
is caused by changes in the middle layers of the corium, consisting
of aggregations of large epithelioid cells, with development of con-
nective tissue, and of yellowish brown pigment in and about the
cells, with fatty degeneration of the connective tissue.

Treatment. — Removal by careful dissection is sometimes em-
ployed, but can hardly be recommended unless under exceptional

548 DISEASES OF THE EYE. [chap, xviit.

circumstances ; the giowtli, moreover, is liable to recur. But good,
and apparently permanent, cures have been effected by means of
radium. Electrolysis too can be used. A platinum needle is passed
about 5 mm. under the growth and parallel to the skin and allowed
to remain a few seconds, five or six such insertions being made
fairly close to each other. A scab forms and comes away in a few
days, and thus in a few sittings the entire growth will have been
attacked. Care must be taken to destroy the whole growth, or a
recurrence will take place.

Palpebral Chromidrosis (xpw/i«, colour; 'H^poaig, sweating). — The
phenomenon of an exudation of pigment upon the eyehds, of which a
good many cases are recorded, has given rise to mu3h discussion. The
opinion held by many is that these cases are always the result either of de-
ception in hysterical individuals, or of accidental circumstances, such as the
exposure of a patient with seborrhcea palpebrarum to an atmosphere
loaded with coal-dust or pigmentary matter, in some manufacturing
district. Of the fact that the appearance has occurred under both of
these conditions there can be no doubt. There would seem also to be
evidence that some genuine cases of colour-sweating on the eyelids have
been observed ; but they must be extremely rare. The discoloration is
blue or black, and occui's in the form of fine powder upon the skin of
one or both eyelids of both eyes. It can be wiped off, and is said to
begin to reappear after a short interval. The subjects of it have been
chiefly young girls, but it has also been seen in women of advanced years
and even in middle-aged men.

The Treatment in a genuine case may consist in the application of a
lotion of liq. plumbi and glycerine ; and, internally, iron, quinine, and
arsenic, along with the regulation of the general system, particularly in
respect of any uterine derangement.

Herpes Zoster Ophthalmicus is a herpetic eruption of the skin
in the region supplied by the ophthalmic division of the fifth nerve
of one side.

Occasionally, in the same case, the second division of the fifth
nerve may be affected, and, yet more rarely, the third division as
well. One or two cases, too, have been published in which the
zoster affected each side of the face.

But by far the most common case is the simple herpes zoster
ophthalmicus, in which only the region supplied by the ophthalmic
division of the fifth nerve is affected ; and of this region it is usually
that portion alone which pertains to the supra-orbital and infra-
trochlear branches that is involved, as is represented in Fig. 229.
The number of vesicles varies much ; there may be but one, or there
may be several, or they may be so numerous as to become confluent.

CHAP. XV in.

THE EYELIDS.

549

Fig. 229.

The appearance of the eruption is often preceded by a feeling of
general discomfort, gastric disturbance, and high temperature. Yet
more commonly the eruption is preceded by supra-orbital neuralgia,
which is often severe. This pain usually continues, but may cease,
after the eruption comes out, and sometimes it persists even for
many months after the eruption
disappears. Photophobia, due to
the irritation of the fifth nerve, is
not uncommon at the commence-
ment of the affection. Along with
the appearance of the herpes the
skin of the forehead becomes red and
swollen, and the appearances are
often mistaken for erysipelas, but the
strict limitation of the eruption by
the vertical middle line of the fore-
head is of itself sufficient to indicate
the diagnosis. The upper lid is
somewhat oedematous and red, and

droops over the eye, and this is much more marked when the skin
of the eyelid itself is the seat of vesicles.

The contents of the vesicles soon become purulent and haemor-
rhage may take place in them. They then gradually dry up, and
form crusts, which conceal more or less deep ulcers, and as these
ulcers often penetrate to the corium they are liable to leave per-
manent scars behind, which at first are red, and later become cf
a glistening white. The entire eruptive process lasts about three
weeks ; and, when it is completed, the sensibility of the affected skin
remains dull for a considerable time. Herpes zoster ophthalmicus
is more common in advanced life than in youth, but it may appear
at any age, and has been observed as early as the sixth month after
birth.

The disease is not associated with danger to the eye, unless
keratitis come on, or, what is much more rare, unless iritis, cyclitis,
or chorioiditis appear. The conjunctiva is almost always slightly
chemotic and injected, or there may be true conjunctivitis ; but
vesicles are not often seen on it.

There is considerable variety in the forms of keratitis liable to
occur in herpes zoster ophthalmicus — viz. herpetic vesicles, phlycte-

550 DISEASES OF THE EYE. [chap, xviii.

nulsc, bullae (any of which may go on to ulceration), superficial
opacity without loss of substance, and parenchymatous opacity,
either diffuse or punctate. The superficial opacities without loss of
substance may disappear completely. Parenchymatous opacity
either clears away completely, or remains as a slight nebula ; while
ulceration leaves, at the least, some opacity ; or, if it become
septic, may seriously endanger the eye. Anaesthesia, more or less
well marked, attends the corneal affections, and remains for a long
time after they recover.

Iritis is very uncommon in herpes zoster ophthalmicus, and is
usually cf a mild type, and iiido-cyclitis and chorioiditis are still
more uncommon.

Herpes zoster ophthalmicus is due to an inflammatory process
in the Gasserian ganglion, as Head and Campbell have shown, and
in the opinion of these authors the skin eruption is caused by intense
irritation of the ganglion cells. The lesion in the Gasserian ganglion
is similar to that found in the posterior root ganglion in zoster of the
trunk and limbs. Head and Campbell believe the affection to be
an acute specific disease — a view suggested by the facts that it
occurs in the course of recognised infective diseases, that it occurs
endemically and epidemically, and that it rarely occurs a second
time. It is probable that the affection may also have a toxic arigin,
as when arsenic has been taken for a long time, and in carbonic oxide
poisoning.

Treatment. — It is doubtful whether treatment has any influence
in curing or in controlling the severity of an attack of herpes zoster
ophthalmicus. Quinine in full doses should be given, and a 1 per
cent, cocaine ointment made with equal parts of vaseline and lanolin
should be smeared lightly over the affected part. Complications in
the cornea or uveal tract are to be dealt with on the principles laid
down in the chapters on diseases of those organs. The patient, unless
the attack be a very mild one, should be confined to bed.

Syphilitic Affections of the Eyelids. — Primary Syphilitic Sores occur
on the eyelids, usually near the margm of the upper or lower lid, or at the
inner or outer canthus, or may occupy the conjunctival surface of the
eyelid. The first a^^pearance is generally a small red swelling which the
patient calls a ' pimple,' and which ulcerates and becomes characteristically
indurated about its base. The margin of the ulcer is clean-cut, and its
floor somewhat exca\'Tited, and covered with a scanty greyish secretion.
Or, without any ulceration, the lid is swollen, greatly indurated, purple,

(HAr. will.] THE EYELIDS. 551

and sliiny ; and in these cases the diagnosis may he somewhat diflicult.
The pre-auricular and sub-maxillary glands are almost always swollen ;
and this is a valuable, although not altogether positive, diagnostic sign,
as it is seen also in tubercular diseases of the conjunctiva. Tlie presence
of spirochoetes in the secretion, or a positive Wassermann test, will deter-
mine the diagnosis. The occurrence of the sore is followed by the usual
constitutional symptoms of syphilis. Very rarely is there any permanent
damage done to the eyelid.

The most common modes of infection are by a kiss from a syphilitic
mouth, or by a finger.

In view of the rarity of this affection, as also of interstitial keratitis
in acquired syphilis, quite a number of cases have been recorded, in
which interstitial keratitis followed in the eye the lid of which had pre-
viously been the seat of a primary syphilitic sore.

Treatment. — Locally, iodoform ointment, dusting with finely powdered
iodide of mercury, or the black wash may be used ; wliile salvarsan, or
the usual general mercurial treatment is employed.

Secondary Syphilis gives rise to ulcers on the margins of the lids, to
loss of the eyelashes, and to the secondary skin affections which attend
it in other parts of the body.

In Tertiary Syphilis a gummatous infiltration of the tarsus — so-called
Syphilitic Tarsitis — may occur, but it is a rare affection. One or both
eyelids, in one or both eyes, may be attacked. Without pain the lid
becomes slowly and gradually hypertrophied, and the integument tightly
stretched and hyperaemic. On palpation, which gives no pain, the tarsus
can be felt to be enlarged and of cartilaginous density. The i^alpebral
conjunctiva is somewhat swollen, but through it the yellowish-white
colour of the gummatous infiltration can be seen, if it be possible to evert
the lid. Ptosis results, and the lid may be so hard and stiff as to render
eversion impossible. The eyelashes fall out, and the pre-auricular gland
is swollen. Although, as stated, the process is remarkable for its freedom
from pain, yet severe pain may be experienced, should a rapid increase
in the gummatous infiltration take place. Under treatment — which
consists of iodide of potash and mercury — the infiltration disappears,
and leaves a normal eyelid behind, or the tarsus may be somewhat atrophied
as a result.

Vaccine Vesicles on the Eyelids are produced by accidental inocula-
tion at the intermarginal part of the lid ; or on the outer surface of the
lid, if the skin be abraded by a finger-nail or otherwise. Sometimes the
vesicle develops into a large ulcer with yellowish floor and hard and ele-
vated margin. There is much pain, much swelling of the eyelid, and
chemosis.

Although distressing for a week or so while it lasts, the affection is
not a dangerous one, further than that a cicatrix in the skin is left behind,
and the eyelashes at the affected part are lost.

Treatment. — A warm chlorate of potash lotion (gr. v ad 5J) is the best
application.

Rodent Urcer (Jacob's ITJcer). — This disease commences as a

552 DISEASES OF THE EYE. [chap, xviii.

small pimple or wart on the skin near the inner canthus, or over the
lacrimal bone, as a rule ; but it may also originate in any other part
of the face. The scab or covering of the wart is easily removed, and
underneath is found a shallow ulcer with a well-defined, raised, and
indurated margin, the skin surrounding the diseased area being
healthy. The progress of the disease is extremely slow, extending
over a great number of years, and in the early stages the ulcer may
even seem to heal for a time, but always breaks out again. In
mild cases the ulceration may remain superficial ; but more usually
it strikes deep, in the course of time eating away every tissue, even
the bones of the face and the eyeball. The latter is often spared
until after the orbital bones have gone.

The disease is an epithelial cancer of a non-malignant or purely
local kind. There is no tendency to infiltration of the lymphatics.
It is rarely seen in persons under forty years of age.

Treatment. — Extirpation of the diseased part with the knife,
followed by the application of chloride of zinc, or of the actual
cautery, used formerly to be employed; and Bergeon's treatment,
with the internal administration of chlorate of potash, and its local
application as a lotion, was also used with benefit for the time.

The Rontgen Ray treatment enables brilliant cures to be effected
in many of these terrible cases. Dr. W. S. Haughton, who is in
charge of the Rontgen Ray department of the Victoria Hospital,
has given us the following description of the method which he finds
to be the most successful in the treatment of rodent ulcer : — When
the ulcer is large, lumpy, or prominent, it is advisable to remove as
much as possible of its floor and margin by excision or cautery, so
as to expose its growing base directly to the Rontgen Rays. The
ulcer is exposed to the rays, at a distance of not less than six inches,
through an accurately shaped window in a mask of led foil. A
layer of cotton-wool or other non-conducting material is placed
between the patient's skin and the lead foil. The affected part is
given two minutes' exposure to the rays every second day, until
definite signs of reaction appear. For superficial ulcers a soft
X Ray tube gives the best results, when deep tissues are affected a
hard tube is preferable. From 10 to 20 sittings, according to the
extent and depth of the ulcer, are usually necessary to effect a cure.
Early cases are of course the most favourable for treatment, but in
far advanced cases — even when the eveball was cone, and the bones

cnAr. xviii.] THE EYELIDS. 553

of the orbit extensively destroyed, with visible pulsations of the
brain through the roof of the orbit — the growth of the disease has
been arrested, and all pain and hcTmorrhage have been stopped.

In rodent ulcers of small extent radium is capable of effecting
good cures. Two or three 5 mg. tubes of first quality radium are
applied to the ulcerated surface for about half an houi, at intervals
of ten days to three weeks, and to a different part of the ulcer at
each sitting, until gradually the whole surface is brought to heal.
The cicatrix left is soft and skin-like. In the early period of the
growth the application for a few seconds of the carbonic acid snow
gives rise to healing in some cases.

Plexiform Neuroma, or Neuro-fibroma is a rare disease of the eye-
lids. It is S8311 as a congenital growth wliich slowly increases in size.
The tumour in general is soft to the touch, but contains many hard strings
and knobs. Pressure on it is painful in some cases. It may attain great
size, and may extend to the supra-orbital, temporal, and malar regions,
giving rise to much disfigurement. Operation is indicated only if the
tumour be markedly progressive, as a satisfactory result is not very easily
attainable, and gangrene has followed in some cases, while in others, where
the growth had to be followed deeply, severe haemorrhage has occurred.
In some instances the tumour has invaded the orbit, and even the cavity
of the skull, after absorption of the orbital roof. Plexiform neuroma is
often accompanied with buphthalmos.

Lymphoma or Lymphadenoma of the eyelids usually occurs as a
bilateral and symmetrical disease, but it does occur, in rare instances, on one
side only. It is frequently associated with leucaemia, or pseudo-leucaemia,
or it may be found in apparently healthy individuals. It often invades
the orbit, and its growth is exceedingly slow and quite painless.

Epithelioma, Sarcoma, and Lupus are all seen in the eyelids, but
require no special description here.

Gangrene of the Eyelid is a rare condition. It may occur as a
consequence of an infected wound of the lid, or from some general infection
of the system, even in influenza, and has been seen as a result of excessive
use of iced compresses.

Clonic Cramp of the Orbicularis Muscle, or of a portion of it,
is often seen, and is popularly known by the name of ' life ' in the
eyelid. It is frequently due to ovei-use of the eyes for near woik,
especially by artificial light, or if there be defective amplitude of
accommodation.

Treatment should consist in the regulation of the use of the eyes
for near work, and the correction by glasses of any defect in the
accommodation.

554 DISEASES OF THE EYE. [chap, xviir.

Blepharospasm, or Tonic Cramp of the Orbicularis Muscle, is

commonly the result of irritation of the ophthalmic division of
the fifth nerve by reflex action, as in phlyctenular ophthalmia
(p. 104) and some other corneal and conjunctival affections ; or
from foreign bodies on the conjunctiva or cornea, etc. ; or it may
continue for some time after the relief of any such irritation. It
occurs, also, independently of such causes, and is then difficult
to account for, unless as a hysterical symptom. Yet, even in these
obscure cases, the spasm is probably often a reflex from the fifth
nerve {i.e. teeth, or nose), and it will be found that pressure upon the
supra-orbital nerve at the supra-orbital notch may arrest the spasm ;
or, if not there, then pressure on the infra-orbital, temporal, malar,
or inferior alveolar branch may have the desired effect.

Treatment. — If the cause of the reflex cannot be ascertained, or
if it have passed away, and if the cramp be still very distressing,
stretching or resection of the branches of the fifth nerve, from which
the reflex proceeds, may be tried. The operation of spino-facial
anastomosis has been successfully employed in some obstinate cases.

Ptosis (tttojo-i?, a fall), or Blepharoptosis, is an inability to raise
the upper lid, which then hangs down over the eyeball. It is either
congenital or acquired; and in the latter case is most usually the
result of paralysis of the branch of the third nerve supplying the
levator.

Persons affected with ptosis involuntarily endeavour to raise the
eyelid by an over-action of the frontalis muscle. The drooping lid
and elevated eyebrow give a peculiar and characteristic appearance.

Paralytic Ptosis. — The Causes of Paralytic Ptosis are similar to
those of paralysis of other branches of the third pair, more especially
exposure to cold draughts of air while the body is heated, and
syphilis or rheumatism affecting the branch to the levator palpebrae
in its course. It may also be due to cerebral disease (p. 500).
The branch to the levator may be paralysed alone, or in conjunc-
tion with other third-nerve branches, especially to the superior
rectus, and the loss of power may be partial or complete.

Some cases of bilateral ptosis in elderly people due to primary
atrophy of the levator palpeV)r?o muscles have been recorded. The
eyelids were elongated and thinned, so that the eyeball showed
plainly through them. The loss of power had in each case been very
slowly increasing for many years.

CHAP, xviii.] THE EYELIDS. 555

The Treatment of a recent case of ordinary paralytic ptosis de-
pends upon its cause. If this be syphilis, then a course of mercurial
inunctions or of iodide of potassium ; if rheumatism, salicylate of
soda or iodide of potassium — with, in either case, protection of the
eye and side of the head by means of a warm dressing and bandage.
Cases in which these remedies have failed, and which have become
chronic, often demand operative treatment. Attempts have been
made, with success in some cases, to obviate the inconvenience of
ptosis by giving support to the lid by wire splints worn like an eye-
glass, or attached to the upper edge of spectacle-frames.

Ptosis due to a cerebral lesion rarely comes within the scope of
treatment.!

Congenital Ptosis is generally present in both eyes. It is
sometimes hereditary, and is often associated with paralysis or
defects of the ocular muscles and with epicanthus (p. 505). It is
due in some cases to an imperfect development of the levator
palpebrae, and in others to an abnormal insertion of this muscle,
its tendon being attached to the tarsus too far back. Aplasia of a
portion of the nucleus of the third nerve has been found in some
cases.

Operative treatment is indicated in cases of paralytic ptosis —
where other measures have produced no result — in ptosis adiposa,
and in congenital cases. Operations for ptosis are very numerous,
but are based on three main ideas, namely {a) shortening the eyelid
by removal (Fergus) or displacement (Hess) of tissues, or by making
use of the levator palpebrae (Everbusch) ; (6) calling in the aid of the
frontalis muscle, and (c) substituting a portion of the superior
rectus (Motais).

A very common proceeding consists in the excision of a suffi-
ciently large oval piece of integument, its long axis lying in the length
of the lid, with the subcutaneous connective tissue and fat, and, in
paralytic cases, a small portion of the orbicular muscle. The fold
of integument to be abscised is seized by two pairs of forceps — one
of them held by an assistant — at the inner and outer ends of
the lid, and by this means the necessary size of the fold is estimated.
The abscission of the fold is performed with a pair of scissors, the

1 Tho value of ptosis as a localising symptom in cerebral disease is
treated of in chap, xvii.

DISEASES OF THE EYE.

[chap. XVill.

margin of the wound lying close to the points of the forceps.
The subcutaneous tissue, etc., is then removed, and the edges of
the wound drawn together by a few points of suture. This is,
however, a rather crude method, and should only be employed, if
at all, in slight cases.

Motais' Operation. — This operation has for its object the trans-
plantation into the upper lid of a flap taken from the superior

rectus muscle ; consequently it is only
suitable for cases of ptosis in which
there is no paralysis of the superior
rectus. In such cases the result is very
satisfactory, and the movements of the
lid follow those of the eyeball better
than they do after other operations
for ptosis. Fig. 230 shows the perfect
elevation of the lid on looking up.

The upper lid is everted, and the
upper fornix is stretched between two
sharp hooks, one being inserted into
the sclerotic above the cornea, and the
other into the ciliary margin of the
everted lid. The conjunctiva is then
divided over the insertion of the superior
rectus, the incision being carried beyond the lateral limits of the
tendon, which is exposed by separating the sub-con junctival tissue,
and capsule of Tenon. The tendon is raised on a large strabismus
hook passed under it from the inner side, and it is seized at its
centre about 4 mm. from its insertion with a double-toothed forceps,
so that an incision may be made with scissors in its centre in front
of the forceps, quite close to the sclerotic, and 4 mm. in width. The
sectioned portion of the tendon is then seized with a broad-ended
fixation forceps, so as to stretch it out well ; and with straight
scissors two parallel incisions are made upwards, one at each side
of the tendon, so that a flap 1 cm. long may be formed in the tendon.
A catgut suture with two curved needles is passed through the flap
near its free margin, and tied firmly on the flap. The central part
of the conjunctival fornix is incised with the curved scissors, and
the ])lades are passed between the tarsus and the soft tissues of the
eyelid as far as the ciliary margin, so as to make a path for the flap

Fig. 230.— Result of Motais'
operation in right eye.

CHAP. XVITT.

THE EYELTDS.

657

of tendon. One of \hv iicedk's cunying its end of tlio suhirc is then
passed along the patli thus made, and caused to emerge through the
skin near the ciliary margin. The second needle is passed in the
same way, its point of exit being a few millimetres from that of the
first. The ends are tied over a pledget of lint, and by this means
the lid will be drawn up and the ptosis relieved. The conjunctival
wound is united with catgut. To prevent lagophthalmos, the lower
lid is raised until it comes in contact with the upper lid, by means
of a suture passed through the former near its ciliary margin, and then
through the skin of the eyebrow where it is tied.

EvershuscJis Operation for Congenital Ptosis (Figs. 231 and

Fio. 231. Fig. 232.

I, levator palpebrae ; o, orbicularis.

232). — The object of the operation is to increase the powder of the
levator by advancing its insertion, or rather by doubling it down
over the tarsus, to wdiich it forms fresh adhesions. Knapp's lid-
clamp is applied, the plate being pressed w^ell up into the fornix ; and,
before the ring is screwed down, the skin of the lid is drawn down,
so that its prolongation just under the eyebrow may be forced into
the instrument. The skin and the underlying orbicularis are now
divided in the entire width of the lid, parallel to its free margin, and
at a distance half-w^ay between this margin and the eyebrow. The

558 DISEASES OF THE EYE. [ckav. xviii.

skill and subjacent muscle are then separated up, both upwards and
downwards, for 4 mm. in each direction, so that the insertion of the
levator may be well exposed. A suture with a small curved needle
at either end is then introduced, by means of one of these needles,
horizontally into the tendon at its insertion, and near the centre of
the latter, in such a way that about 2J mm. of the tendon may be
included in the suture. Each needle is now passed vertically down-
wards between the tarsus and orbicularis, and brought out at the
free margin of the lid at a distance from each other of about 2 J mm.
Two more such double sutures, one in the temporal, the other in the
nasal, third of the tendon, are similarly applied. The margins of
the horizontal skin and muscle wound are now drawn together, and
then the three sutures are closed tightly. It is desirable to slip glass
beads over the ends of the sutures before tying them, to prevent
cutting into the margin of the lid. Both eyes are bandaged, and
the sutures are left in for a week or more.

While the foregoing and other operations relieve the ptosis,
they are liable to give rise to some unsightly cicatrices, and are
sometimes not permanent in their effect. With a view^ to obviate
these drawbacks, Carl Hess has devised the following operation.

Hess' Operation. — The eyebrow having been shaved, an incision
{a a, Fig. 233) is made in its whole length, and carried through the
skin and subcutaneous tissue ; and, starting from this incision, the

skin of the lid is separated with the

" '■ W (^(itk ir-- " scalpel from the underlying orbicular

J0^^ ^ ^^^5^ muscle nearly as far as the ciliary

margin (dotted line in Fig. 233).
b."^ ' — ' — ' / When the haemorrhage has ceased,

:-^^^.. _ ■-':^J<i^^ three silk sutures, each armed with

??^J^7//^^ two needles, are introduced, one at

the centre and one towards either
Fig. 233. ^^^^ o^ ^^^ eyelid, and about half-

way between the eyebrow and lid
margin (6, Fig. 233), or somewhat nearer the latter. The needles
of each suture are inserted about 5 mm. apart, and, being passed
from without inwards through the skin, they are brought out
in the space made by the skin dissection. The needles are now
passed deeply under the upper border of the incision in the
eyebrow, and brought out a few millimetres above it (at points

CHAP, xviir.] THE EYELIDS. 559

repie«ontc(.l by tliiee pairs of duts in Fig. 2:3:^). The two ends uf
eac-li suture are tied over a small roll of lint or a Int of rubber drainage
tube, and drawn tightly enough to relieve the ptosis by producing
a fold in the skin flap. The wound in the eyebrow is united by
some points of suture. The sutures are allowed to remain for eight
or ten days. The permanent result depends on the union and
cicatrisation of the extensive raw surfaces in their new position.
The operation causes little or no disfigurement, as the artificial fold
falls in about the same situation as that which is present in the normal
eyelid ; while the cicatrix in the eyebrow is concealed by the hairs
when they have grown again. In Figs. 234 and 235 a section of the
eyelid before and after tightening of the sutures is represented.

ixa

Fig. 234. Fig. 235.

Fig. 234. — The needles are passed in at a through the skin of the
nd,«and brought out at a' through the skin and subcutaneous tissue above
the eyebrow.

Fig. 235. — When the sutures are tightened a is closely approximated
to a'.

Freeland Fergus' Operation. — This operation is employed for all
kinds of ptosis. It can be performed painlessly by infiltration of
the eyelid with a weak solution of eucaine. The eyelid is stretched
upon a spatula inserted under it, and an incision is made parallel
to, and a few millimetres distant from, the edge of the lid. The
incision extends from end to end of the eyelid, and is carried through
the skin and muscle. A second incision is made, extending nearly
in a semicircle from one extremity to the other of the first incision.
It also is carried through the skin and muscle, which are then dis-
sected off the face of the tarsus. A portion of the tarsus is now
excised along with the conjunctiva adherent to it, the extent of
this excision depending upon the amount of effect desired. When

5lK) DISEASES OF THE EYE. [chap, xviit.

the ptosis is almost total, nearly the whole of the tarsus above
the first incision is removed. In lesser degrees of ptosis smaller
excisions suffice. Six sutures are finally inserted, three deep and
three superficial. The deep sutures are best made of absorbent
sterilised catgut. The superficial ones can be of this material or of
silk. The three deep sutures are used to unite the tough fibrous
membrane which passes from the occipito-frontalis to the eyelid
with that portion of the tarsus which remains in the lid below the
level of the first incision. The superficial sutures are employed to
unite the edges of the skin wound. The operation gives great
mobility to the eyelid.

A remarkable and rare condition is Congenital Ptosis, with Associated
Movements of the Affected Eyelid, during the action of certain muscles. It
is most commonly the left lid which is affected, and the paralysis may be
congenital or acquired. Three conditions have been observed — viz.
(1) elevation of the drooping lid when the eye is adducted, (2) when the
eye is abducted, or (3) when the mouth is opened. A synchronous con-
traction of the pupil has been noticed in some cases, while in some the
elevation of the lid occurs also with a lateral motion of the jaw, and with
deglutition. Gower's explanation is that in these cases the levator is
not wholly supplied by the third nerve, but partly also by nerve fibres
which take their origin in the nucleus of the fifth pair, and which also
supply the external pterygoid and digastric muscles. But this theory does
not hold good in all cases, for Bull describes a case in which the lid was
raised when the head was bent back, thus stretching the digastric, and he
regards these as associated or reflex movements. In some instances the
lid can be raised voluntarily on closing the other eye. Needless to say,
no remedy can be applied for relief of this condition.

Ptosis Adiposa is a rather rare condition which occurs in young
people. The skin of the eyelid is puffed out, is slightly hypersemic
and finely wrinkled, and on palpation no feeling of resistance is felt, nor is
there any pitting on pressure. We have operated on four such cases,
and in all we removed from under the orbicularis a roll of fat, which
was quite well defined, but appeared to be continuous with the orbital
fat at the inner side only. These cases somewhat resemble, and are
sometimes grouped with, the cases of blepharo-chalazis which occur in
old people, and in which the skin of the upper lid hangs loosely over the
tarsal portion of the hd.

Hysterical Ptosis may be unilateral or bilateral. It is not a true ptosis,
but is caused by a slight spasm of the orbicularis, and in consequence
the eyebrow on the affected side is always lower than on the other, exactly
the reverse of the state of affairs in paralytic ptosis. For Sympathetic
Ptosis, see p. 501.

The term ptosis is also given, although not very correctly, to cases in
which increased weight of the lid from inflammation, oedema, or tumours,
causes it to droop.

CHAP. xvTTT.l THE EYELIDS. r^(^\

* LagOphthallUOS (Au-yws, a hare, us it was suppused tliat this
animal sleeps with its eyes open ; o<^^uA/xos), or inability to close the
eyelids, is most commonly due to paralysis of the portio dura, and
is then associated with the other symptoms of the latter affection.
On an effort to close the lids being made, the eyeball is rotated up-
wards under the upper lid, owing to the associated action of the
superior rectus ; and in sleep this upward rotation also occurs — a
fact which explains, to a great extent, the immunity of the cornea
from ulceration in many of these cases. Lagophthalmos may also
be due to orbital tumours pushing the eyeball forwards, to exoph-
thalmic goitre, to staphyloma, or to intra-ocular growths distending
the walls of the eyeball — in all of which conditions the eyelids are
often mechanically prevented from closing over the eyeball, or can
be closed only by a strong effort of the will. The danger to the eye
depends upon the tendency to ulceration of the cornea from its
dryness, caused by exposure to the air, and from foreign substances
not being removed from it by nictitation.

In cases of non-paralytic lagophthalmos, protection of the cornea
by keeping the eyelids closed with a bandage, or by inserting a few
epidermic sutures in the margins of the eyelids to draw them
together, should be our first care. Tarsoraphy may be employed
in those cases where circumstances indicate that it would be useful
— e.g. in some cases of exophthalmic goitre, or of staphylomatous
eyeball.

In paralytic cases, the primary cause of the paralysis (syphilis,
rheumatism, etc.) must be treated so long as there is a prospect of
restoring power to the muscle. Locally, galvanism and hypodermic
injections of strychnia may be employed. During cure the cornea
should be protected as above. In incurable cases, the opening of the
eyelids must be reduced considerably in size by an extensive tarso-
raphy performed according to one of the following methods.

The Operation of Tarsoraphy consists in uniting the margins of
the upper and lower lids in the neighbourhood of the external com-
missure, so as to reduce the size of the opening of the eyelids. The
commissure should be caught between the finger and thumb, and
the edges of the lids approximated, so as to enable the operator to
form an estimate of the required extent of the operation. A horn
spatula is then passed behind the commissure, and the necessary
length of the margin of each lid, including the bulbs of the cilia,
36

56^ DISEASES OF THE EYE. [chap, xvtii.

is abscised with a sharp knife. The raw margins are then brought
together with sutures.

Priestley StnitJis Method. — Both lids are split rather deeply by
intermarginal incisions {a, Fig. 236), and sutures are then passed
in such a way as to draw together the bottoms of the two grooves.
When the sutures are tied, the anterior and posterior lips of the
incisions are flattened out (c, Fig. 236), and thus a broad contact is
obtained between the two raw surfaces. Two or more sutures may
be applied.

■r^^-^-^^

ib) ic)

Fig. 236.

(a) Shows incisions and method of inserting suture ; (6) front view
and (c) side view (section) when sutures are tied.

Pfluger's Method consists in passing one, two, or even three double
sutures subcutaneously around the eyelids, about 5 mm. from their
margins. The ends are drawn together, so that the eye is concealed
by the pouch thus formed, and tied. From time to time the sutures
are tightened, until finally they cut through, and by this means a
subcutaneous ring-cicatrix is produced. Should the first ring-
cicatrix not sufficiently close the eyelids, the operation can be re-
peated even more than once again. The method is tedious and
painful.

Symblepharon (o-vV, together ; jSXecfiapov, the eyelid) is an ad-
herence, partial or complete, of the eyelid to the eyeball. It is
usually the result of burns of the conjunctiva by fire or caustic
substances. The shortening of the conjunctival sac, which is seen
as the result of pemphigus (p. 89) or of granular ophthalmia, and
which is described under the heading of Xerophthalmos (p. 96), is
not properly termed symblepharon. If the symblepharon interfere
seriously with the motions of the eyeball, or if it cause defect of
vision by obscuring the cornea, it becomes desirable to relieve it by
operation. Should it consist of a simple band stretching from lid

PTTAr. XVTTT.

THE EYETADS.

563

to eyeball, it iimy be .severed by lig;itiiie, and d the baud be biuad,
two ligatures may be employed, one for eitlier half. A syudjlepharou
wluch oceupies a considerable surface cannot be got rid of in this
way ; and for such eases a transplantation procedure like that of
Teale may be employed, the great difficulty in dealing with these
cases being the tendency there is to re-union of the surfaces, unless
one or both of them be carpeted with epithelium.

In Teale's Operation, if we suppose the case to be similar to that

Fig. 237.

Fig. 238.

represented in Fig. 237, an incision is carried along the line of the
margin of the cornea at A, through the whole thickness of the
symblepharon, and the lid is dissected off from the eyeball as far as
the fornix. Two conjunctival flaps are now formed, as at B and C
in Fig. 238, and one of them {B) is turned to form a covering for the
wounded surface of the inside of the eyelid, while the other (0) is
used to cover the bulbar surface (Fig. 239), the flaps being held in
their places by fine sutures. That part of the symblepharon which
is left adherent to the cornea soon atrophies and disappears. No
great tension of the flaps should exist
as they lie in their new positions.

Teale, again, has suggested the
formation of a bridge-like conjunc-
tival flap above the cornea, and the
removing of it across the latter to
cover the loss of substance situated
below\ After the sutures which keep
the flap in its place have been introduced, the latter is separated
at its bases.

A simple plan, which w^ould be applicable to such a case as that
depicted in Fig. 237, where the adhesion is not very extensive, and
perhaps even to some more extensive ones, consists in dissecting the

Fig. 239.

")r)4 DISEASES OF THE EYE. [CHAr. xvitt.

cuiijuiietival process off the cornea, and tlicn tiuning it down on
the raw inner surface of the under lid, and fastening it there with a
suture or two. We have done this with complete satisfaction.

Harlan'' s Operation.- — This is specially applicable to extensive
symblepharon of the lower lid, and differs from the foregoing opera-
tions in that it provides a covering of skin, and not of mucous mem-
brane, for the raw surface of the under lid. Operations on the same
principle have been proposed by Snellen and by Kuhnt. An in-
cision (A B, Fig. 240) through the whole thickness of the eyelid, and
corresponding in length with the latter, is made along the lower
margin of the orbit. Below this a skin flap (C D ) is then formed. The
flap is dissected up, and the incisions are carried a little more deeply
as A B is approached, to enable the flap to turn the more readily.
The flap is then turned up as on a hinge, slipped through the button-
hole, and sutured securely to the inner surface of the under lid.
After a time the skin surface turned towards the eyeball becomes

considerably modified, so as to be
somewhat like mucous membrane.
The bare space left by the removal
of the strip of skin is covered with-
out strain by making a small hori-
zontal incision (D E) at its -outer
Fig "iicT extremity, and forming a sliding

flap.
Trails plantation Operations. — The transplantation of mucous
membrane from the lips or cheek has been used in extensive symble-
pharon, but the drawback to mucous membrane flaps, where two
opposing surfaces have to be covered, is that when the superficial
epithelium of the mucous membrane is thrown oft' there is
danger of the surfaces uniting. Thiersch and other skin flaps are
preferable.

Blepharophimosis {(3Xl4)apov, eyelid; (fil/jnoo-L^, narrowing] is a
contraction of the outer commissure of the lids, with consequent
diminution in size of the opening between the latter ; and is com-
monly due to shortening of the skin, from long-continued irritation,
caused by the discharge in a case of very chronic conjunctivitis.

It is remedied by a Canthoplastic Operation. The outer com-
missure is divided in its entire thickness, in a line which is a pro-
longation of the line of junction of the lids when closed, by a single

CilAl'. XVIII.

THE EYELIDS.

565

stroke of strong straight scissors, one blade of which has been
passed behind the commissure. The integiimental incision should
be made a little longer than that in the conjunctiva. An assistant
then draws the upper lid up and the lower lid down, so as to make
the wound gape. The conjunctival margin and the dermic margin
are now united in the centre by a point of suture (C, Fig. 241), while
two more sutures (A and B) are applied, one above and the other
below the first. This operation is also employed in cases of granular

Fig. 241.

ophthalmia and of purulent conjunctivitis, when it is desired to
relieve pressure of the eyelid on the globe.

Distichiasis (St's, tivice ; aTL^o^, a row) and Trichiasis {rplxos, a
hair). — The first of these terms iirdicates the growth of a row of
eyelashes along the intermarginal por-tion of the lid in addition to
the normal row ; while trichiasis indicates a false direction given
to the true cilia. Both conditions are often found co-existing, and
often, too, they are present along with entropion. They may both
be produced by chronic blepharitis (p. 543), or by chronic granular
ophthalmia (p. 73). Some cases of congenital distichiasis and
trichiasis have been recorded. The symptoms the false cilia produce,
and the dangers to the eye attendant on them, are due to their
rubbing on the cornea, which causes pain, blepharospasm, and
opacity of the cornea, or even ulceration of it.

56C

DISEASES OF THE EYE.

[chap, xvrit.

Operations for Distichiasis and Trichiasis : —

Epilation. — The false cilia may be pulled out with a forceps ; but
this cannot be regarded as a cure, as the hairs grow again ; yet, if
repeatedly removed, they grow finer and finally cease to be renewed.

Electrolysis. — A needle is attached to the negative pole, and its
point passed into the bulb of the eyelash to be removed, the positive
pole being placed on the temple. On
closure of the circuit, if the battery be
working properly, bubbles of gas should
rise up round the needle, and a slough
forming at the root of the hair, the latter
becomes loose, and is removed. It does
not grow again, for the bulb is destroyed.
Each hair must be separately operated on.
proceeding is very valuable where only a few
are to be dealt with.

Excision. — When some half-dozen hairs close
together are growing wrong, the simplest and best
plan is to completely remove them by excision of
the corresponding portion of the ciliary margin. A
fine knife is passed into the intermarginal region
at the place corresponding with the hairs to be dealt
with, and a partial division of the lid into two
layers, as in the Arlt-Jaesche operation [vide infra),
is effected. A triangular-shaped incision in the skin
of the lid is then made, including the erring hairs,
the whole flap is excised, and the margin of the loss
of substance is drawn together with sutures.

Transplantation, or Shifting, of the marginal
portion of the integument containing the hair bulbs,
true and false. One of the oldest and most valuable
operations of this kind is that of Jaesche, modified by Arlt. It
is performed as follows : — Knapp's, or Snellen's, clamp (Fig. 242)
having been applied to prevent bleeding, the lid in its whole
length is divided in the intermarginal part into two layers (Fig.
243), the anterior containing the orbicular muscle and integument
with all the hair bulbs, the posterior containing tlie tarsus and
conjunctiva. The incision in the intermarginal portion is about
5 mm. deep. 'A second incision is now made through the integument

Fig. 24:

CHAP. XV 11 1.]

THE EYELIDS.

507

of the lid, parallel to its margin, and from 5 to 7 mm. removed from
it. This incision also extends the whole length of the lid. A third
incision is cariied in a curve from one end to the other of the second
incision. The height of the curve is proportional to the effect re-
quired, varying from 4 mm. to 7 mm. The piece of integument
included between the second and third incisions is dissected off with
forceps and scissors, without any of the underlying muscle being
touched, and the margins of the loss of substance are brought to-
gether by sutures. By this procedure the lower portion of integu-
ment, containing the hairs and their bulbs, is drawn up and away
from contact with the cornea.
After this operation the condition
is sometimes liable to relapse.

Van Millingen^s Operatio7i con-
sists in splitting the eyelid, as in
the Arlt-Jaesche operation, from
end to end, sufficiently to produce
a gap (5, Fig. 244) 3 mm. in width
at the central part of the lid, and
gradually becoming narrower to-
wards the canthi. The gap is
usually kept open by sutures
passed through folds of skin on the
upper lid {a a a), by means of
which also the lid is prevented
from closing for twenty-four hours
at the least, but we have not found
that these sutures are essential.
As soon as the bleeding has ceased, a

strip of mucous membrane of the same length as the incision in the
lid, and 2 to 2J mm. in breadth, is cut out with two or three snips
of a curved scissors from the inner surface of the patient's under
lip, on which an eyelid clamp has been placed to prevent bleeding,
and is introduced at once into the gap in the intermarginal space. It
should then be pressed into position with a probe. According to
Van Millingen, sutures are superfluous ; but they are desirable for
the sake of security, and do no harm. We usually employ three
sutures, one at either end of the flap and one in the centre ; these
sutures are not tied over the edges of the flap, the mucous membrraie

Fig. 243.

)68

DISEASES OF THE EYE.

[chap. XV hi.

Fig. 244.

being merely held in place by a knot on the end of each thread, the
needles after piercing the flap being carried up under the skin, and
the free ends of the threads are then loosely tied together on the
outer surface of the skin. It is important, in order to obtain a
neat effect, to clean the fat and submucous tissue from the flap

before applying it ; and
while this is being done
the flap should lie on a
warm porcelain plate.
The eyelid is then covered
over with a piece of lint,
on which is spread a thick
layer of xeroform vase-
line, and over this is
placed a wad of cotton-
wool and a bandage.

It is not advisable to
transplant small strips of
mucous membrane if the
trichiasis be partial, as
partial trichiasis is often only the commencement of complete
trichiasis, and therefore, in these cases, the filling up of the entire
length of the intermarginal space with a flap of mucous membrane
should be effected. One or two fine sutures, which serve to unite
the margins of the wound in the lip, arrest the bleeding at once,
and accelerate union of the part, which is generally completed in
twenty-four hours.

This is the most effectual method of permanently providing a
good intermarginal space, and in thus definitely relieving the con-
dition.

Entropion (er, in; Tpiiroj, to turn), or Inversion of the Eyelid,
is due to organic change in the conjunctiva or tarsus, or to spasm
of the palpebral portion of the orbicular muscle. A large proportion
of the former class of cases is the result of chronic granular ophthal-
mia, and is most common in the upper lid. Spastic entropion occui's
in the under lid only. It is frequent in old people (senile entropion)
from relaxation of the skin of the eyelid, and is also produced by
the wearing of a ])andage after operations.

Treatment.— ~li the tarsus of the upper lid be not distorted,

CHAP. XVIII.]

THE EYELIDS.

.")()<)

organic entropion can often be corrected by one of the methods
described for trichiasis and distichiasis. But many of these cases
are accompanied by, or rather due to, abnormal curvature with
hypertrophy of the tarsus.

In such cases the operation must include an attack on the tarsus
itself.

Snellen's Operation. — An eyelid clamp is applied. About 3 mm.
from the margin of the lid, and parallel to it, an incision is made
through the skin alone, extending the whole length of the lid. The
orbicular muscle is exposed by dissection of the skin upwards, in
order to promote retraction of the latter, and along the edge of the
lower margin of the wound a strip, about 2 mm. broad, of the orbicular

Fig. 245.

Fig. 24G.

muscle is removed, and the tarsus to the same extent is exposed to
view, A wedge-shaped piece, corresponding with the exposed part
of the tarsus, is now excised from it with a very sharp scalpel, the
edge of the wedge pointing towards the conjunctiva, which latter,
however, is left intact. The hypertrophy of the tarsus, which is
always present, facilitates this procedure. A silk suture carrying a
needle on each end having been prepared, one needle is passed from
within outwards through the band of muscle and integument left
at the margin of the lid. The second needle is also passed from
within outwards through the upper lip of the tarsal loss of substance,
and then from within outwards through this same marginal band,
at a distance of about -1 mm. from the point of exit of the first needle.
The ends of the suture are now tied together, a small bead having
first been strung on each to prevent it from cutting through the

570 DISEASES OF THE EYE. [chap, xviii.

skin. Three such sutures are employed. The accompanying figures
(245 and 246) make the foregoing description more intelligible.

Berlin's Operation. — An eyelid clamp is applied. The first in-
cision lies 3 mm. above the margin of the lid, extends its whole
length, and divides it in its entire thickness, including the conjunc-
tiva. The skin and muscle at the upper edge of the wound are
pushed or dissected up so as to expose the tarsus. The upper edge
of the tarsal incision is now seized at its centre with a finely toothed
forceps, and an oval piece with the adherent conjunctiva, about 2 to
3 mm. wide in its widest part, and in length corresponding with that
of the eyelid, is excised from it with a fine scalpel. The wound is
closed with three sutures through the skin. If it be thought desirable
to increase the effect, a skin-flap may be excised from the lid. The
objection to this operation, that a portion of the mucous membrane
is removed, is not of importance. The method is a good one.

Spastic Entropion of the lower lid, as the result of bandaging,
usually disappears when the use of the bandage is given up ; or, if
the bandage must be continued and should the inverted lid cause
irritation, a dermic suture at the palpebral margin which is fastened
to the cheek below will give relief.

Senile Entropion of the lower lid is, of the spastic kinds, the one
which most commonly needs operative interference. The methods
in general use for it are : —

The Excision of a Horizontal Piece of Skin, with a portion of the
underlying palpebral part of the orbicular muscle, so as to give
rise to sufficient cicatricial contraction to draw the margin of the lid
outwards.

The foregoing, and other such measures, produce a good result
at the time, but are sometimes followed by recurrence of the en-
tropion. Hotz, believing the cause of this to be that the cicatrix,
whether dermic or dermo-muscular, upon which the result depends,
has no point (Cappui ; and consequently, while it may draw the
eyelid out, is liable to draw the skin of the cheek up, and thus to
neutralise its desired effect, has proposed the following ingenious
operation : —

Hotz's Operation. — A horn spatula is inserted under the lid, and,
at 4 to 6 mm. below the margin of the latter, a horizontal incision is
made through the skin from the inner to the outer end of the lid.
This incision is at the boundary between the palpebral and orbital

CHAr. XVIII.]

THE EYELIDS.

171

portions of the orbicular muscle, and just over the lower margin of
the tarsus. An assistant then draws the upper edge {a, Fig, 247) of
the wound upwards with a forceps, while the surgeon draws the
lower edge (6) downwards, in this way exposing and stretching the
orbicular muscle. A few strokes of the knife in the direction of the
incision -are now sufficient to separate the palpebral portion (/) of
the muscle from the orbital portion {f), and to lay bare the lower
edge of the tarsus (<), which is of a yellowish tendinous appearance.
That part of the palpebral portion of the muscle which covered the
lower edge of the tarsus, and which was drawn up with the palpebral
edge of the first incision, is now removed with forceps and scissors,

to the extent of about 2 mm. in
width, through the whole length
of the lid. All such muscular
fibres, also, which may still ad-
here to the lower third of the
tarsus must be carefully cleaned
off, and now the palpebral skin
may be brought into union with
the tarsus. Four sutures are
generally applied, about 5 mm.
apart. The needle is passed
through the palpebral skin, close
to the margin of the wound
The bare tarsal edge is then seized in the forceps, the needle
placed perpendicularly on it (at d), and carried through it by a
short downward curve until its point appears (at c) below the
tarsus in the tarso-orbital fascia (/). The needle is now passed
out through the lower edge of the incision (at h), care being taken
that none of the fibres of the orbital portion of the muscle are
included in the suture. Upon the suture being tightly closed, the
edges of the skin wound are drawn into the tarsus, and become
adherent to it. The sutures may be removed about the third day.
If the first incision be placed too far from the margin of the lid,
there will be no result, as the traction upon the palpebral skin will
be too slight. If the incision be placed too close to the margin,
the traction may be so great as to interfere with the union of the
skin and tarsus. In this operation the tarsus affords the fulcrum,
which Hotz thinks is wanting in other methods. The tarsus of

Fig. 247.

(at a).

572 DISEASES OF THE EYE. [chap, xviii.

the lower lid is sometimes badly developed, and the result of the
operation may then be disappointing.

Ectropion or Eversion of the Eyelid. — Of this there are three
kinds : (1) Muscular, or Spastic. (2) Cicatricial. (3) Paralytic.

Muscular Ectropion occurs only in the lower eyelid and may
have its starting-point in oedema of the conjunctiva, which averts the
edge of the eyelid, and this eversion becomes increased and encour-
aged by spasm of the palpebral portion of the orbicular muscle, so
that the term palpebral paraphimosis might be given to the con-
dition. In the recent stage it may generally be remedied by suit-
able conjunctival measures. In chronic cases operative measures
are usually required.

Muscular ectropion is often seen in old people, and is then given
the name of Senile Ectropion. Here it is due to atrophy of the
palpebral portion of the orbicularis of the lower lid, and relaxation
of the skin of the face. When these have resulted in slight eversion
of the inferior punctum, a flowing of tears is produced, causing some
excoriation of the skin and edge of the lid, which then increase the
tendency to ectropion. If the condition be not extreme, with
secondary changes in the conjunctiva, slitting up of the canaliculus,
with the use of any simple ointment for the lids, and mild astring-
ents for the conjunctiva, will give much relief. In pronounced cases,
a more active treatment of the conjunctiva, and the performance of
tarsoraphy, or the application of Snellen's sutures, or one of the other
operations described below, are demanded.

The following operations are amongst the best for the correction
of muscular ectropion : —

Snellen'' s Sutures. — A silk ligature is threaded at either end with
a needle of moderate size and curve. The point of one of these
needles is passed into the most prominent point of the exposed and
everted conjunctiva, and brought out through the skin 2 cm. below
the edge of the lower lid. The other needle is entered in the same
way 5 mm. from the first, and made to take a nearly parallel course,
the points of exit on the cheek being 1 cm. apart. Equal traction
is applied to each end of the suture, while the lid is assisted into its
place by the finger. The suture is tied on the cheek, a small roll of
sticking-plaster having been inserted under it to protect the skin
from being cut. Two, or even three, such sutures may be required,
and they are allowed to remain for several days.

CHAr. xvTTT.] THE EYELTDS. 573

Frcdand Fcnjus Mclliod. — Fergus puiiils uut that the two-tliirds
of the exposed eonjuiietival surface of the lower eyelid, from the
fornix towards the free Jiiariiin, are usually eoniparativel}' healthy,
the marginal third alone being diseased. He has devised the follow-
ing procedure, which consists in excision of the diseased tissue. An
incision is made through the conjunctiva from the inner to the outer
canthus, demarcating its healthy from its diseased portion. With
forceps and scissors the conjunctiva covering the healthy portion
of the eyelid is freed from the nnderlying structures right down to
the region of the retro-tarsal fold. The hypertrophied tissue is next
excised throughout its entire extent, so as to restore as it were the
original margin of the lid, and finally the conjunctiva is drawn up
and secured by a few points of suture to the margin. The success
of the operation depends on the thoroughness with which the
excision of the hypertrophied tissue is effected.

Kuhnfs Operation for Senile Ectropion is an admirable one. It
consists in splitting the lower eyelid in its central third, so that the
conjunctiva and tarsus are left in the posterior layer, while the
anterior layer contains the orbicularis and the skin. A triangular
piece, the base of which is formed by the margin of the lid, is then
excised from the posterior layer, and the margins of the loss of sub-
stance in the latter are brought together by three or four points of
suture. Lest they should give way too soon, it is necessary to place
these sutures very securely. A puckering of the anterior layer,
opposite the line of sutures in the posterior layer, is produced,
but subsequently disappears, and a suture which unites the most
prominent point of the pucker with the margin of the tarsus assists
in this. Or, if the lid be split, say, to an extent twice as long as
the base of the triangular piece to be excised, the puckering can
be distributed at either end of the incision. It is by reason of the
shortening of the posterior layer of the split eyelid that the eversion
is corrected. We frequently use this operation, and always with
gratifying results.

Kenneth Scott's Operation. — The external canthus and the tissues
beyond it are thoroughly divided by a pair of strong scissors. The
lower eyelid, which is usually the affected one, is then seized, and its
margin stretched sufficiently outwards, parallel to the border of the
other lid, so as to restore the palpebral aperture to its proper appear-
ance ; the portion of eyelid margin thus made to extend beyond the

574 DISEASES OF THE EYE. [ch.aj-. xviir.

site of the external canthus is removed, along with its contained eye-
lashes, by slicing it with a sharp kuife. The upper and lower eyelids
are then brought together, so that the original outer extremity of
the upper eyelids approximates exactly to the new extremity of the
lower eyelid. They are secured in this position by passing a silver
wire suture, vertically downwards through the substance of the
upper lid, continuing it out through that of the lower one, and then
twisting the ends firmly together. Two of these retaining stitches
may be introduced close together if necessary. The edges of divided
skin, along with the deeper muscular tissues, including that part
which recently formed the outer end of the affected eyelid, are
simply stitched together with a continuous fine silk suture.

No dressing other than a repeated dusting with some fine anti-
septic powder need be used. The silk stitches may be removed in
six days' time, the silver ones being left in for five or six days longer.
Scott states there is never any puckering apparent beyond the newly
formed canthus, and the small linear cicatrix is lost amongst the
other lines often found there.

Cicatricial Ectropion is caused by chronic blepharitis with
dermatitis of the skin of the eyelid (p. 543). It is also caused by
scars in the eyelid from caries of the orbit, or from wounds or burns,
which destroy the integument of one or both eyelids. Cicatricial
ectropion caused by burns of the face and eyelids in epileptics or
children who have fallen into the fire is not uncommon. The
burnt skin of the eyelids is replaced by a granulating surface ; and,
when cicatrisation of this surface commences, the free margin of
the upper lid is drawn up towards the eyebrow, and that of the
lower lid down towards the cheek, the conjunctival surface of the
eyelids in consequence becoming everted, and the cornea exposed,
as the eyelids cannot now be closed.

For the higher degrees of ectropion due to chronic blepharitis
— or, as it is called. Blepharitis Ectropion — in the lower lid, Kuhnt's
Operation consists in the splitting of the eyelid in its whole extent
into two layers, an anterior (skin-muscle) and a posterior (tarsus-
conjunctiva) and the shifting of the layers on each other so that the
anterior one is elevated while the posterior one is lowered. It is
performed as follows : —

The lower eyelid is stretched in a lid-clamp. An incision is made
through the skin (Fig. 248) immediately below the eyelashes. The

(■•IfAr. XVTTT.]

THE EYELIDS.

roots of any eyelashes wJiicli m;iy he exposed should be removed
Avithout injury to the skin. An incision is n(j\v made from end to
end in the intermarginal portion of the lid (dotted line in Fig. 248),
and as deep as the inferior orbital margin in the temporal and nasal
directions. The intermarginal incision is continued in the nasal
direction as far as the anterior crista lacrimalis, with a depth of
rO to 1'5 cm., care being taken not to injure the canaliculus. The
temporal extension of the intermarginal incision is made to pass
steeply upwards and outwards, and then rectangularly outwards
and downwards (compare Fig. 248). If the anterior (skin-muscle)

Fig. 248.

layer be now tightly stretched, the further splitting of the lid below
the inferior orbital margin can easily be accomplished, and without
injury to the tarso-orbital fascia. (In Fig. 248 the punctated portion
represents the undermined region.) At the external canthus the
tarso-conjunctival layer is then divided as though for a cantho-
plastic operation (p. 565). In order to lower the posterior layer,
from three to five sutures, each with two needles, are passed through
it, being entered between the lower margin of the tarsus and the
conjunctival fornix into the space between the anterior and pos-
terior layers of the split lid. They are then passed through the
anterior layer so that they may appear through the skin 1 cm.
below and concentrically to the orbital margin. The suture which
lies in the most nasal direction should be placed about 2 mm.

r^7fi DISEASES OF THE EYE. [CHAr. xvitt.

to tlie outside and below the puiietum lacrimale, so that the nasal
half of the posterior layer may be well drawn down. In order to
raise the anterior layer at its temporal end, there is removed
from the outer end of the upper lid a wedge-shaped piece of skin
and underlying tissue of 1-0 to 1'5 mm. in width at its base {A,
Fig. 248). The margins of the space that results are drawn together
with two or three sutures armed with two needles placed deeply
in the edge of the wound, and a few superficial sutures are added,
in order to draw the margins neatly together. To secure a sufficient
elevation of the nasal end of the anterior layer, especially for the
punctuni lacrimale, a double-armed suture is similarly passed through
the anterior layer 4 mm. below its margin and opposite the middle
of the internal palpebral ligament, and is tied to the palpebral
ligament close to the lacrimal crest. The anterior layer is now
very tense. Finally, the posterior layer is drawn down by aid of
the double-armed sutures, which are tied on the cheek. The sutures
may be removed in seven or eight days.

For the relief of the extreme ectropion due to burns of one or
both eyelids, the best method is that of Wolfe by Skm Trans'planta-
tion. It is performed as follows : —

In the first place the eyelid — let it be the upper eyelid — is dis-
sected down into its place to the utmost limit, so that the most
extensive raw surface possible may be obtained. The margin of
the lid, having been drawn over the lower lid, is fastened to the
cheek with three points of suture. A portion of skin, suited as re-
gards shape, and about one-third larger (to allow for shrinkage)
than the raw surface of the eyelid, is then taken from the inside of
the arm, and having been carefully freed of all its subcutaneous fat
and connective tissue, is laid upon the raw surface, and secured
to it by a large number of fine interrupted sutures around the
margin. Or, if the margin of the skin surrounding the raw surface
be dissected up, the edge of the graft can be slipped under it, and
secured in its place by this means. It is essential in the case of
grafts on the lower lid, to prevent them from becoming infiltrated
and sodden with the lacrimal or conjunctival secretion, and in order
to keep the graft dry we are in the habit of filling up the hollow
at the side of the nose and the inner canthus with a liberal supply
of boric acid pow^der. A non-irritating dry dressing, or an oint-
ment dressing, is applied, and the graft usually heals on. In most

CHAT. XVIII.] THE EYELIDS. 577

cases the most superficial layer of the epidermis peels off after a few-
days. This method of grafting was introduced by Wolfe and Lefort,
and it may be employed in all these cases with most satisfactory
results.

It is important to preserve and utilise any part of the skin of
the eyelid which remains, especially its ciliary border with the eye-
lashes. The thorough cleaning of the flap from its subcutaneous
fat and connective tissue is also important, as otherwise an unsightly
and lumpy effect is produced when the flap has healed on. While
this cleaning is being done, the flap should lie on a warm sterilised
porcelain plate. The flap should not be applied to the raw surface
until all oozing of blood from the latter has ceased.

The transplantation of a flap with pedicle from the forehead,
temple, or cheek is also used to repair an eyelid ; but, owing to the
thickness of the integument, the result is cosmetically less satisfac-
tory than that given by a graft fi'om the arm, w^hile the tendency
to shrink is quite as great.

Some prefer Thiersch grafts to dermic grafts, and state they are
more easily applied to the raw surface, and do not differ in colour
from the surrounding skin when healing is completed. It is desirable
to obtain one continuous graft of the whole size of the w^ounded
surface.

Paralytic Ectropion is due to lo«s of power in the orbicular
muscle in cases of paralysis of the seventh nerve. It occurs in
the lower lid only, which falls outw^ards by its own weight when
not kept in contact with the eyeball by the tone of the muscle.
The condition is remedied by a tarsoraphy (p. 561) when all hope
of recovery of the paralysed nerve has to be abandoned.

* Ankyloblepharon {dyKvkq, a string ; (^\i(fiapov, an eyelid) is
a uniting of the upper and lower eyelids along their margins. It
may be partial or complete, and often goes with symblepharon.
Like the latter, it is usually caused by burns and ulcers.

The condition can only be relieved by operation, of w^hich the
result is often unsatisfactory, owing to the difficulty of preventing
re-union taking place at the canthi. To avert this, it is always
necessary to cover the wounded surface with conjunctiva or skin.

Injuries of the Eyelids. — All kinds of injuries of the eyelids (con-
tusions, incisions, burns, etc.) are common.

In consequence of the looseness of the integument, oedema and
37

578 DISEASES OF I'BE EYE. [chap, xviit.

ecchymosis, one or both, are often seen in a marked degree as the
result even of slight injuries.

Owing to the direction of the fibres of the orbicularis, an incised
wound of the eyelid, if in the vertical direction, will gape, while a
similar w^ound in the horizontal direction will not do so. Hence the
scar left after the former wound is apt to be very visible, but that
after the latter may be almost imperceptible. If the eyelid be
divided vertically in its entire thickness, unless union by first inten-
tion can be obtained, a deep furrow is left in the eyelid, and, perhaps,
at its margin an unsightly coloboma.

The result of burns of the eyelids has been treated of at p. 574.
Emphysema of the eyelids is sometimes seen after a blow on the
eye, and is a sign of fracture of the orbit complicated with a
communication between the subcutaneous connective tissue of the
eyelids and the nose, the ethmoid sinus, the frontal sinus, or the
antrum of Highmore. An emphysematous lid is swollen, soft, and
crepitating to the touch.

Ecchymosis of the lower lid, usually with ecchymosis of the lower
portion of the conjunctiva, after falls or blows on the head, is a
sign of fracture of the base of the skull, the blood making its way
along the floor of the orbit.

Simple ecchymosis of the eyelids from blows, commonly known
as ' black eye,' never gives rise to further complication. It requires
some fourteen days or more, according to the quantity of blood
extravasated, before the eye recovers its normal appearance.

Treatment. — Injuries of the eyelids, of whatever kind, are of
course treated upon general surgical principles. Incised wounds
should be carefully and neatly drawn together with sutures as soon
after the injur}^ as possible, and with antiseptic precautions.
Emphysema may be assisted in its absorption by the application
of a rather tight bandage, and directions should be given to the
patient to blow his nose as gently as possible, so as to avoid recur-
rence of the condition.

* Epicanthus is a congenital deformity, generally binocular, associ-
ated in the most pronounced cases, with paralysis of the levator
palpebrae (ptosis), and usually also of the rectus superior, with a
narrow palpebral fissure. It consists of a fold of integument at
the inner canthus which conceals the caruncle from view (Fig. 201),
and gives the appearance of great breadth to the bridge

CHAP, xviii.] THE EYELIDS. 579

of the nose. In young children epicanthus may exist without
ptosis, and in many of these cases the condition disappears with
the growth of the bridge of the nose. If necessary the deformity
can be somewhat diminished by the removal of an oval piece of
skin from the l)ridge of the nose, its long axis being vertical and its
width varying according to the effect retjuired. When the margins
of the wound are brought togethei', the abnormal epicanthal
folds become flattened out.

* Congenital Coloboma of the upper lid— sometimes associated
with a dermoid cyst of the limbus of the cornea corresponding with
the cleft in the lid — and even congenital absence of the eyelids, have
been occasionallv observed.

CHAPTER XIX.

DISEASE OF THE LACRIMAL ^ APPARATUS.

Overflowing of tears from the eye may be due either to hyper-
secretion or defective excretion. In the former case the lacrimation
is more or less of a temporary phenomenon, is independent of disease
of the lacrimal apparatus, and is occasioned by reflex irritation
arising in the eye from such causes as diseases of the cornea or uveal
tract, foreign bodies, misplaced cilia, etc., or the hypersecretion may
be of central origin, emotional or hysterical. On the other hand,
a persistent oyerflow of tears, in the absence of any source of irri-
tation, is with rare exceptions caused by obstruction or inefficient
action of the channels whereby the tears are excreted, and is usually
termed epiphora (eVtc^opa I'SaKpuoj, a flow of tears).

The commonest diseases of the lacrimal apparatus are those
which cause epiphora, and these will first be described.

Malposition of the Punctum Lacrimale.- — The punctum in the
lower lid is more efficient for carrying off tears, than that in the
upper lid, and a derangement of the lowec punctum alone is sufficient
to give rise to epiphora. Normally the punctum lies against the
eyeball and cannot be seen, unless the observer draws the inner end
of the lid away from the eye. Inversion of the punctum accom-
panies entropion of the lower eyelid, while eversion of it is present
with ectropion of the lid. A slight eversion, quite sufficient to
cause epiphora, may exist without any marked ectropion of the lid,
and it is these cases which more properly belong to this chapter.
They are the result generally of some chronic, although it may be
slight, skin affection of the lower lid, which draws the inner end of
the latter slightly away from the eyeball.

1 Lacrima, a tear.

2 In this chapter, and elsewhere in the book, the terms punctum lacri-
male and canaHculus refer to the inferior passage, unless it be otherwise
expressly stated.

580

CHAP. XIX.] THE LACRIMAL APPARATUS. 5H1

Inversion of the punctum can only be relieved l)y an
entropion operation on the eyelid.

Stenosis, and Complete Occlusion of the Punctum
Lacrimale. — Either of these conditions may result from |!|

conjunctivitis, oi- from marginal blepharitis, although
they may uot appear for a length of time after those
affections have passed away, and the original affection
may have been so slight as to have escaped the observa-
tion of the patient. In stenosis the size of the punctum
may become so extremely minute, that even the normal
flow of tears is too copious to pass through it. Complete oc-
clusion is probably only a more advanced stage of stenosis.

The Treatment, in cases of eversion of the punctum
without marked ectropion of the lid, of stenosis, and of
complete occlusion, is similar, namely, the opening up
of the punctum, and its conversion into a slit. This
is done with a Weber's knife (Fig. 2-19), the probe-
point of which is passed into the punctum in cases of
eversion, forced into the small opening in cases of
stenosis, or forced through the usually thin covering of
the punctum in cases of occlusion. In doing this the
lower lid should be stretched rather tightly by a finger
of the surgeon's left hand placed near the external
canthus. The probe-point having entered the punctum,
the edge of the knife is turned slightly towards the
eyeball, and the instrument is pushed on into the
canaliculus, until 2 mm. of the latter has been opened
up, and is then withdrawn. If the edge of the knife
be directed outwards in this proceeding, the incision
comes to lie on the outer edge of the intermarginal
portion of the lid, and not in contact with the eyeball ;
consequently the result is unsatisfactory, for the tears
are not carried away, and the disfigurement produced Fig. 2-4U.
may be considerable. A slitting up of the whole, or
the greater part, of the canaliculus in these cases is unnecessary,
and interferes with the physiological action of the tear passage.
For two or three days after the little operation, it is necessary
to pass a probe along the portion of the canaliculus which has
been slit uj), to prevent union taking place.

582 DISEASES OF THE EYE. [chap. xix.

When, as sometimes happens in old people, and occasionally
even in the middle-aged, from relaxation of the orbicularis, the
inner end only of the under lid is everted, the excision of a small
flap of conjunctiva somewhat after the manner of Fergus (p. 573)
will restore the punctum to its normal position.

Obstruction of the Canaliculus. — The canaliculus may be di-
minished in its calibre, or entirely closed, by contraction, which is
the result of inflammation that has extended to it from the con-
junctival sac. It is not possible to diagnose the presence of either
of these conditions, which may be associated with stenosis or oc-
clusion of the punctum lacrimale, except by the introduction of a
very hue probe into the canaliculus. The passage may also be
obstructed by an eyelash, a chalky deposit, or a mass of streptothrix.

The diagnosis of streptothrix in the inferior canaliculus — it
rarely affects the upper canaliculus — is made by the following signs
and symptoms : — Lacrimation ; the presence of a creamy-yellow
discharge at the inner canthus, without dacryocystitis ; congestion
of the caruncle and neighbouring parts of the conjunctiva. On
everting the inner end of the lower lid, the region corresponding with
the canaliculus is seen to be rounded and swollen on its conjunctival
aspect. The lacrimal punctum is enlarged, stands out from the
eyeball when the patient looks up, and is filled w^ith creamy exuda-
tion. On palpation, a hard cylindrical mass can be felt in the
canaliculus. At a later stage, severe purulent inflammation of the
canaliculus comes on, with marked swelling of the eyelid in the
neighbourhood, and pain. The greenish-yellow dacryolith con-
tained in the canaliculus usually consists of a streptothrix, which
some regard as actinomyces.

Treatment. — Where there is merely diminution in the calibre of
the passage, the introduction of a conical stylet (Fig, 249) or of
probes, increasing in size, is frequently sufficient to effect a cure.
If dilatation fail, recourse must be had to slitting up the canaliculus ;
but, if it can possibly be avoided — that is, if a less extended opening
will answer — the passage should not be slit up in its entire length.
At least 3 mm. of its median end ought to be left intact, as other-
wise regurgitation of tears from the lacrimal sac is liable to trouble
the jDatient ever afterwards. If the canaliculus be completely closed
by adhesions, so that a fine probe cannot be pushed through it,
it becomes necessary to rip it up with the point of any small knife,

CHAP. XIX.] THE LACRIMAL APPAHATUS. 583

following the known course of the passage from the outside. If the
canaliculus be closed as far as the opening into the sac, or if only
at that point, the obstruction must be pierced with the point of a
fine knife. A difficulty in all these cases is to keep the passage
patent when once formed. A plan which affords tolerable certainty
of this is the frequent passage of probes into the sac until the ten-
dency to closure seems to have ceased ; but even under favourable
conditions recurrences of the closure are apt to occur.

Streptothrix in the lower canaliculus is readily cured by slitting
up the passage and evacuating its contents, or by expressing the
contents when possible without dividing the canaliculus, and
syringing out with oxycanate of mercury.

Stricture of the Nasal Duct is usually the result of simple acute
swelling of its mucous membrane in a catarrhal attack, which has
originated in the nasal mucous membrane. Or, it is caused by
membranous or cicatricial contraction of the mucous membrane
resulting from long-continued chronic catarrh. It also occurs in
consequence of disease of the bones of the nose — e.g. in syphilis,
acquired or congenital, and from blows Avhich fracture the bridge
of the nose.

Treatment. — It is desirable to commence the treatment by
syringing the nasal duct, the fine point of an Anel's syringe being
introduced into the punctum lacrimale and canaliculus. It may be
necessary to dilate the punctum with the stylet (Fig. 249) before the
syringe can be introduced. In some cases, where the obstruction
is merely a plug of mucus, the syringe may at once effect a cure.
Stricture due to acute inflammatory swelling of the mucous mem-
brane should be treated by the injection of weak alum or other
astringent solutions into the lacrimal sac, or through the nasal duct,
by means of an Anel's syringe ; and attention should be paid to
the condition of the nasal mucous membrane. Probing here should
not be attempted, lest it injure the delicate swollen mucous
membrane of the duct.

Membranous or cicatricial strictures are best treated by means
of probes in the manner proposed by Sir William Bowman. As
the process is a painful one, cocaine should first be injected into the
passages with the syringe. Smearing the probe with some aseptic
oil or simple ointment also facilitates matters. Probes as large
as numbers 3 or 4 can Ije introduced into the canaliculus if the

584

DISEASES OF THE EYE.

[chap. XIX.

punctum be first dilated. Should there be any difficulty, or if
larger sizes are needed, the inferior canaliculus is slit up to a slight
extent so as to admit the point of one of Bowman's smallest probes,
which has been given a curve to suit that of the nasal duct. With
a finger of the left hand (Fig. 250), if it be the patient's left eye,
the surgeon stretches the lower lid, and, entering the probe with
the right hand into the canaliculus, he pushes it gently along
its floor until the point reaches the lacrimal bone (Fig. 250, position
No. 1). The point being kept pressed against this bone, the direction
of the probe is now altered, by carrying its free end upwards to-

FiG. 250.

wards the bridge of the nose, until the point w^hich is in the lacrimal
sac is directed towards, or aimed at, the sulcus between the ala
of the nose and the cheek. The probe in this position (Fig. 250,
position No. 2) corresponds with the prolonged axis of the nasal duct,
down which it is pushed slowly and with gentle pressure. If it be
the right eye, the surgeon reverses his hands, or operates from
behind the patient. Any obstacles met with are overcome, if
possible, by an increase of the pressure ; but if, at any part of the
passage, much difficulty be encountered, rather than that any
violence be used, further manipulation should be postponed to

CHAP. XIX. 1 THE LACRIMAL APPARATUS. 585

another day ; and it will often be found that at the second or third
visit the probe is passed with comparative ease. Thicker Bowman's
probes are gradually introduced at successive sittings, until the
largest size has been reached.

The most common seats for membranous oi- cicatricial stricture
of the nasal duct are at the upper end, where it enters the sac, and
where it is at its narrowest ; and at the lower end, where it is mainly
exposed to catarrhal processes spreading from the nostril.

Weber's probes are conical, and of very large calibre at their
thickest part. The objection to such large conical probes is that
when passed into the nasal duct, their thickest part, w^hich is 3 to 4
mm. in diameter, corresponds with the upper end of the duct, which
is its narrowest part, being only 3 mm. in diameter. Consequently,
the probe becomes more or less impacted at this place at each opera-
tion, and this impaction, from injury of the mucous membrane
and periosteum, is liable ultimately to give rise there to hypertrophy
of the periosteum, and finally to stricture ; so that, while the im-
mediate effect of their use is perhaps brilliant, the ultimate result
is often the reverse. When used by the inferior canaliculus, their
size makes it necessary to slit that passage in its entire length, and
the entrance of the passage into the sac must be enormously dilated
by so large an instrument, both of w^hich circumstances are most
undesirable. The same objection applies to the large probes
introduced by other surgeons. Syringing the nasal duct should not
be performed immediately after passing a probe, lest cellulitis be
set up.

To prevent closure of the duct when once made free, silver or
leaden styles can be left in situ, the upper end being curved so as
to lie out on the cheek. The style is at first removed daily, and
the duct syringed, until any existing inflammation and discharge
have almost ceased. The intervals are then increased ; and as
soon as practicable the patient is taught to remove the style and
to replace it himself. When he is able to do this easily, he is
directed to leave the style out foi some hours each day, and
finally to wear it only at night.

Very obstinate membranous strictures can sometimes be freed
by electrolysis.

The cases of stricture which are the most favourable for cure
are those due to infiannnatory swelling of the mucous membrane,

586 DISEASES OF THE EYE. [chap. xix.

and next in order come those caused by membranous or cicatricial
contraction, while strictures due to bony obstructions are incurable.

Now and then cases of persistent lacrimation will be met with,
in which the nasal duct and the rest of the lacrimal apparatus seem
to be in perfect order. These cases are often due to a catarrhal
affection of the nasal mucous membrane, slightly involving the very
lowest extremity of the nasal duct. Applications directed towards
relief of the nasal affection are here indicated.

Blennorrhoea of the Lacrimal Sac, or Chronic Dacryocystitis, is
commonly caused, in the first instance, by stricture of the nasal
duct. In consequence of this stricture the tears and the normal
mucous secretion of the lining membrane of the sac are retained,
and offer favourable conditions for the growth of micro-organisms,
such as the pneumococcus, which is the one usually present, or
more rarely an influenza-like bacillus or the pneumo-bacillus.

But cases of lacrimal blennorrhoea are seen in which no stricture
of the nasal duct is found. In many of these cases there has been
a temporary stricture, due to catarrhal swelling of the lining mem-
brane of the duct, which has subsided without treatment, and the
duct has again become free, while the lacrimal blennorrhoea, to which
the stricture gave rise, continues. It is probable, however, that
lacrimal blennorrhoea may occasionally come on where there has
never been a stricture of the nasal duct, and merely as an extension
of catarrh from the nostrils, especially in cases of ozsena, or as an
extension of catarrh from the conjunctiva.

Tubercle is occasionally the cause of dacryocystitis, but it is
not possible to make a clinical diagnosis between these and the
more common cases, if the mucous membrane of the lacrimal sac
alone be diseased. But these cases are very prone to be attended
with the formation of a fistula, lined by granulations which often
extend into, and undermine, the surrounding skin. In many, but
not in all cases, the tubercular infection of the sac extends from the
nostril, or from the conjunctiva, one or other of which is the primary
seat of the disease. The sac itself may be the primary seat of the
tuberculosis, with quite healthy nasal and ocular mucous membrane.

Sijmpoms. — The patients as a rule complain merely of lacrima-
tion. Some, more observant of themselves, may have noticed a
swelling, known as a lacrimal tumour or mucocele, in the region
of the lacrimal sac; and also that the conjunctival sac, especially

CHAP. XIX.] THE LACRIMAL Al'PARATUS. 587

when the swelling is pressed upon, becomes now and then more or
less filled with a somewhat viscid and opaque discharge, which
obscures the sight until wiped away. Occasionally there is no
lacrimal tumour, for the contents of the sac may not be copious
enough to distend it markedly.

In order to ascertain in each case of epiphora whether lacrimal
blennorrhoea be present, the surgeon presses with his finger over
the lacrimal sac, when, if there be blennorrhoea, the discharge will
be evacuated through the puncta into the conjunctival sac. But
occasionally, where there is a deeply situated sac, owing to a pro-
minent anterior lacrimal crest, although dacryocystitis is present,
it may not be possible to express any discharge from the sac. Or,
in those cases in which there is no longer a stricture of the nasal
duct, the discharge may pass downwards into the nose, and the
patient will feel it in his nostril, out of which he can blow it.

Conjunctivitis must sometimes be regarded, not as the cause,
but rather as the effect of a lacrimal blennorrhoea, by reason of
infection from the lacrimal sac. Blepharitis, too, is seen as a
further result of infection from the discharge in old-standing cases.
The most serious complication, or consequence, of chronic
dacryocystitis is the serpiginous ulcer of the cornea, caused through
infection by the pneumococcus (p. 124).

Treatment. — It is important, in the first place, to ascertain
whether there be a stricture of the nasal duct, and lor this purpose
water should be injected by means of an Anel's syringe through the
canaliculus into the duct. If the fluid make its way freely into
the nose or pharynx, it may be taken for granted that the nasal duct
is not obstructed ; but if, instead of passing through — or only under
high pressure — it distend the lacrimal tumour to a greater size, a
stricture may be assumed. If stricture of the nasal duct be present,
it should be relieved, if this can be done, by a few probings ; excessive
probing only aggravates the condition of the sac. Should there be
no stricture, and also before and after any existing stricture has
been relieved, the treatment consists in the very frequent pressing
out of the contents of the sac by the patient, so that no distension
of it may occur ; and in doing this he should endeavour to cause the
discharge to pass down the nose rather than into the eye. Frequent
deep massage of the sac, which the patient can be taught to perform,
is useful. Injections into the sac to relieve the catarrh should be

588 DISEASES OF THE EYE. [chap. xix.

made daily by the surgeon. Peroxide of hydrogen and protargol,
in a 15 or 20 per cent, solution, are good applications for introduction
into the lacrimal sac. The latter should first be washed out with a
physiological salt solution. Other fluids which have been recom-
mended are Sol. Argyrol 25 per cent., Sol. Hydrarg. oxycyanat. 2
per cent., Sol. Potas. perman. 1 in 2500, and tincture of iodine.
When using the last, or indeed when strong solutions of any kind
are employed, the eye should be protected by a small pledget of
absorbent cotton.

Any conjunctivitis or abnormal condition of the nasal mucous
membrane should be treated. But there are many cases in which
nothing short of extirpation of the lacrimal sac will bring about a
radical cure of this troublesome, and even serious, complaint.
Indeed, for chronic cases this operation is now commonly recom-
mended at the first consultation, in view of the disappointing results
obtained from other methods.

Extirpation of the lacrimal sac. — Prior to the operation, the
contents of the sac should be expressed, and its cavity washed
out with a sterilised salt solution.

The patient should be deeply anoesthetised, or an effectual local
anaesthesia may be obtained as follows :^About fifteen minutes
before the operation a few drops of the following solution are in-
jected subcutaneously in three or four places : 1 c.cm. of a 1 per
cent, solution of cocaine, to which is added 3 minims of a 1 in 1000
solution of adrenalin. By this means, too, the haemorrhage, which
is usually troublesome, is reduced to a minimum. As a result of
the injection slight oedema of the region may be seen a few days
after the operation.

The two important guides which define the position of the
lacrimal sac are the crest of the lacrimal bone and the tendo oculi.

The skin having been painted with tincture of iodine, an incision
down to the bone and about 2*5 cm. in length is made over the
anterior lacrimal crest. It begins about 4 mm. above the internal
palpebral ligament, and ends about 5 mm. below the commence-
ment of the bony lacrimal duct. As a rule the palpebral ligament
is not divided by this incision, and has now to be separated with
the scissors close to its insertion. Some surgeons consider it un-
necessary and undesirable to divide the palpebral ligament, because
it is likely to lead to some disfigurement, no matter how carefullv

ruw. XIX.]

THE LACRIMAL APPARATUS.

589

the sutures may be upplietl, but this is not our experience. Miiller's
specuhini is then inserted to draw aside the Hps of the wound,
and Axenfeld's specuhnn is inserted from the nasal side into the
upper and lower angles of the wound as deep as the periosteum,
to check the ti'oubk^sonie hicmorrlia^e which proceeds mainly from
those angles (Fig. 251). If there be bleeding from the small arteries,
they are, if possible, seized and twisted, while general oozing of
blood is moderated l)y means of compresses soaked in solution of
adrenalin with cocaine or hydrogen peroxide. The fibrous capsule
of the sac is carefully incised along the crest, care being taken

Fig. 251.

that the sac itself is not opened. The anterior wall of the sac,
greyish blue and shining, then becomes exposed in the cavity. To
remove the sac the surgeon separates its inner wall from the perios-
teum with the closed blunt ends of the scissors, or with a small
elevator ; then the fundus of the sac, along with the strong fibrous
capsule which is here adherent to it, is drawn forwards, and with
a few strokes of the scissors is separated from its bed, and the scissors
are passed behind the sac from above and the posterior wall similarly
separated. The fundus of the sac is then drawn inwards and for-
wards, and the outer and what remains attached of the anterior
surface are made free. Finally, the sac is cut off close to the bony
canal, and, if there be no impervious stricture present, the mucous

590 DISEASES OF THE EYE. [chap, xix.

iiieiiibraiie of the duct is curetted with a suitable sharp spoon, or
a fine olive-sliaped electro-cautery is applied to it. The wound is
closed by two or three deeply placed sutures, special care being
taken to secure the palpebral ligament to its insertion. An aseptic
dressing, with graduated pressure, should be applied to keep the
walls of the cavity in contact.

Should the sac be o^^ened during the operation, its total extir-
pation will be rendered much more difficult ;
Ej ' and if any portion of the sac be left behind,
the object of the operation is likely to be frus-
trated by a return of suppuration. If the sac
be not excised in its entirety, the suspicious
places must be destroyed by curetting. Where
there is a fistula of the sac, or where there has
been phlegmonous dacryocystitis, or where
there has been excessive probing of the nasal
duct, the operation is rendered difficult by jlji

reason of adhesions. [k

The wound heals rapidly by first intention, |!s|

leaving a fine cicatrix which causes practically l|<

no disfigurement. P

Fig. 252. Another method, and one which we prefer, j {

is to dissect the sac from below upwards. The ^3

incision having been made, the skin is freed for a short |

distance at either side and held apart with Rollet's two
small retractors, which have the advantage of being less
in the way than the self-retaining ones, their position
can be more easily controlled and altered if necessary,
they are less injurious to the tissues, and they avoid the
forward displacement of the edges of the incision, which ^ „

the self -retaining retractors cause, and which increases
the depth of the cavity in which the sac lies. The crest of
the lacrimal bone is next defined with the finger, the incision
is carried down to the bone immediately in front of it, and with
Rollet's rugine (Fig. 252) or special elevator (Fig. 253) the inner
wall of the sac with the periosteum is separated from its bed in the
lacrimal groove. The sac is then cut with scissors as low down as
possible, where it is seized with an artery or fixation forceps, drawn
forwards, and its attachments dissected upwards with the scissors.

CHAP. XIX.] THE LACRIMAL APPARATUS. r,01

After the removal ol the sac, the lacrinial gruove and siiiTouiKliiig
parts should l)e inspected in order to see if any portion may have
been left. Care must be taken during the dissection of the sac
not to go too deeply or too much towards the inner canthus, other-
wise in the former case the orbital fascia will be cut through as shown
by the appearance of orbital fat, and in the latter event the con-
junctiva may be buttonholed at the inner canthus.

After extirpation of the suppurating lacrimal sac, a source of
danger to the eye has been removed, and the patient has been
relieved of a troublesome and disfiguring complaint. The lacrima-
tion is less after the operation than before it, not, as has been stated,
because the lacrimal gland undergoes atrophy, for no such atrophy
takes place, but rather owing to elimination of the fifth nerve reflex
from the walls of the diseased sac and from the inflamed conjunctiva.
Indeed, unless the surface of the eye be exposed to some consider-
able irritation, e.g. cold wind, foreign body, etc., or there be some
psychical emotion, the lacrimation is in no way disturbing, notwith-
standing the complete closure of the lacrimal passage consequent
on the operation. Should the lacrimation in some instances be
troublesome, removal of the palpebral portion of the lacrimal gland
is indicated (p. 594). Eemoval of the orbital portion of the gland
is seldom needed, as its functions seem to cease after removal of the
palpebral gland, probably owing to closure of its ducts consequent
on removal of the latter gland. Yet a retention tumour of the
orbital gland does not ensue.

It is desirable to instruct the patient that he should inform any
surgeon he may subsequently consult for epiphora that his lacrimal
sac has been removed, lest futile and perhaps harmful probing of the
nasal duct should be attempted.

Dacryocystorhinostomy , or the formation of an opening leading
from the sac into the nose through the lacrimal bone, is being per-
formed by some surgeons as a substitute for removal of the sac.
In Toti's method the operation is performed from the outside,
whereas West's is altogether intranasal.

Acute Dacryocystitis {^aKpvw, to weep ; Kvo-Ti?, a bladder). —
Acute inflammation of the lacrimal sac most usually comes on when
chronic lacrimal blennorrhoea is already present. Caries of the
nasal bones may cause it, and it occurs idiopathically, probably as
the result of exposure to cold.

.'502 DISEASES OF THE EYE. [chap. xtx.

The region of the lacrimal sac and the surrounding integument
become swollen, tense, and red, and these conditions often spread
to the lids, giving an appearance which is sometimes mistaken for
erysipelas ; but the history of the case, showing the previous exist-
ence of lacrimal obstruction, etc., will assist the diagnosis. Great
pain accompanies the inflammatory process. Gradually the region
corresponding with the lacrimal sac becomes the most prominent
part of the swelling, and the abscess, pointing there, opens. When
the pus has been discharged the inflammation subsides, and the
opening through the skin may either close, the parts resuming their
normal functions, or the opening may remain as a permanent fistula.

The difference between chronic blennorrhoea of the lacrimal sac
and acute dacryocystitis, besides the fact that one is a chronic and
the other an acute inflammatory process, is that the former process
is confined to the mucous membrane of the sac, while in the latter
the submucous tissue is involved, with phlegmonous inflammation
as the result.

Treatment. — In the early stages poultices and purgatives should
be employed. As soon as palpation of the sac indicates the presence
of pus, it must be evacuated. This can be effected either through
the canaliculus, by opening it up to its entrance into the sac, or by
an incision through the integument over the sac. The latter is the
better method, as it admits of free access to the interior of the sac.
On the next day the walls of the sac are to be freely touched with
solid mitigated nitrate of silver ; or a plug of cotton-wool soaked
in a strong solution of nitrate of silver may be inserted into its cavity,
and left there for some hours ; or various astringent solutions may
be injected into the sac. The aim of the treatment, whatever it
be, is to secure a rapid return of the mucous membrane to its
normal condition. If stricture of the nasal duct be present, it must
be treated pari passu. By these means the discharge from the sac
is arrested, and the external opening gradually closes.

If a fistula should form, it may be made to close, in many cases,
by simply freeing an existing stricture of the nasal duct ; or, it may
be necessary to pare its edges, and bring them together by sutures ;
or, especially if there be a long fistulous passage, the galvano-cautery,
in the form of a platinum wire, can be applied with advantage.

Dacryoadenitis {dak-pvw, to iceep ; ddrjv, a gland), or Inflammation
of the Lacrimal Gland. — This is a very rare affection. It occurs in an

r-HAr. XIX.] THE LACRIMAL APPARATUS. 593

acute and in a snb-acutc form, and is usually symmetrical in each eye.
The acute form is characterised by swelling of the upper lid, especially
in its outer tliird, by chemosis, by diminished mobility of the eyeball
upwards and outwards, with displacement downwards and inwards, by
local pain often radiating into the frontal region, and by pain on pressure
over the gland. On pressure, the tuberous and swollen gland may be
felt, unless a?dema of the lid should interfere. In the sub-acute form there
is neither ojdema nor chemosis, and little or no pain, and the diagnosis
depends on the presence of a hard and lo])ulated mass under the outer
tliird of the iipper lid, which may displace the globe and interfere with
its motion upwards and outwards.

Dacryoadenitis occurs in gonorrhoea, even long after the acute stage
of the latter is passed, in epidemics of mumps with or without parotitis,
in influenza, diphtheria, measles, and scarlatina. In all these instances
it must be regarded as the result of toxic absorption, and having lasted
from about three to fourteen days it undergoes resolution with complete
recovery.

Dacryoadenitis may also be caused, without any conjunctivitis, by
dii'ect infection with the staphylococcus, streptococcus, or pneumococcus,
each of which has been found in the inflammatory products, and these
cases are liable to go on to suppuration, with formation of abscess. They
are usually on one side only.

Finally, cases of tubercular dacryoadenitis have been recorded. The
direct clinical diagnosis of these cases cannot be made — the suspicion
only of their nature, from the presence of tubercular disease in other parts
of the system, can be raised.

Treatment. — Treatment of any toxaemia which may be held to be
present. Locally hot fomentations relieve pain and promote resolution.
When abscess forms, it generally points in the conjunctival fornix, and is
to be opened there. Should tubercle be suspected, removal of the entire
gland is indicated.

Tumours of the Lacrimal Gland. — Tumours of the lacrimal gland
are rare. Sarcoma is the most common of the new growths here, with
its mixed forms fibro-, myxo-, adeno-, and lympho-sarcoma. Adenoma
is also common, and lyinphoma, angioma, and some other varieties have
been observed. In the beginning, the outer third of the upper lid seems
swollen, but palpation shows this to be caused by a tumour behind the
lid, but not in it, and also that the tumour originates in the orbit. Gradually,
by pressure of this growing tumoiu% the eyeball becomes displaced for-
wards and inwards, and its motions are curtailed in the upward and outward
direction. In many instances the growth extends backwards into the
orbit Ijehind the globe, and then the direction of the displacement is
more markedly forwards. The tumour may become fixed to the orbital
margin, or the roof of the orbit may be involved and even perforated, and
vision may be affected, if the optic nerve be pressed on.

Treatment. — Extirpation of the growth is indicated. If the case come

under care at an early stage, the tumour can be reached and effectually

removed, either through an incision made through the lid parallel to the

outer half of the orbital margin ; or, the external commissure having

594

DISEASES OF THE EYE.

[chap. XIX.

been divided, and the upper lid turned up — through an incision made in
the conjunctival fornix. In later stages, especially when the tumour has
extended deeply into the orbit, Kronlein's operation (p. 618) is indicated.

Tubercular Tumour of the Lacrimal Gland. — A few cases of tubercular
tumour of the lacrimal gland have been recorded. The tumour presented
itself as a very hard mass, about the size of an almond, freely movable
under the skin, and unattended by pain. In some instances the history
had extended over several years, and in others has lasted for some months
only. In the majority of the cases there was tubercular disease elsewhere
in the system, bvit in one instance there was none, nor was there any
hereditary disposition to tubercle.

Treatment. — Extirpation of the gland.

Cysts of the Lacrimal Gland. — These are rare. The most common
of them is Dacryops, a term applied to a retention cyst, which occurs
almost exclusively in the palpebral portion of the gland, and may attain
the size of a hazel nut, and which appears as a more or less transparent
bluish swelling in the outer part of the upper fornix.

Treatment. — Excision of a portion of the outer wall of the cyst.

Symmetrical Chronic Swelling of the Lacrimal and Salivary Glands.
(Mikulicz's disease). — In this remarkable affection there is enormous
swelling of each lacrimal, parotid, and submaxillary gland, while the sub-
lingual glands and small salivary glands in -the cheek are also swollen,
the whole producing a striking alteration in the physiognomy of the
patient. The disease has an acute and a chronic form. The former
may run its course, attended by some fever, in a week or ten days, and
can be treated with hot fomentations locally, and salicylate of soda inter-
nally. The chronic form is reckoned by many to be a manifestation
of leiTcaemia or of pseudo-leucaemia, or it may be tubercular, and its treat-
ment is in this way indicated.

Extirpation of the Lacrimal
Gland. — This operation is performed
by making an incision through the
integument under the outer third of
the orbital margin ; the subjacent
fascia is dissected up, the gland drawn
forward with a hook, and dissected out
with a scalpel. Or, if it be considered
sufficient to remove the palpebral
portion, this can be done from the
conjunctival surface, by separating
the lids widely at the outer canthus
with blunt hooks, while the patient
looks well downwards and to the nasal
side, when the palpebral gland will become prominent in the upper
fornix (Fig. 254) ; the conjunctiva over it is then incised, and the

Fig. 254.

CHAP. XIX.] THE LACRIMAL APPARATUS. 5 Of

gland can be seized and ont out with scissoi's. This partial removal
may be performed for persistent lacrimation when other means fail.
As ah-eady stated, when a large tumour of the gland is present,
Kronlein's operation is often needed. The absence of tears, which
follows upon extirpation of the lacrimal gland, is not serious for
the eye : foi- iioiinally the gland secretes very little, unless undei-
the stimulus of a fifth nerve or psychical reflex. Under other
conditions, the surface of the eye is kept moist mainly by the con-
junctival secretion, which consists not merely of mucus, l)ut of a
watery fluid sufflcient even if there be no secretion of tears — as
in extirpation of the lacrimal gland where there is paralysis of the
fifth nerve — to keep the surface of the eye moist.

Occasionally removal of the lacrimal gland is followed by a
rather obstinate miico-purulent discharge from the conjunctiva.

OHAPTER XX.

DISEASES OF THE ORBIT.

The position of the eyeball in the orbit is subject to individual
variations. As a rule the cornea projects very slightly beyond an
imaginary line drawn from the upper to the lower margin of the
orbit, so that a ruler placed in this position would touch the closed
upper lid and exercise only slight pressure on it.

Exophthalmos or Proptosis.^ — One of the most common signs
in many diseases of the orbit is displacement of the eyeball forwards,
w^hich is usually accompanied by more or less lateral or vertical
displacement. In slight degrees of proptosis the relative positions
of the eyes can be best compared by observing the level of the cornea
from behind and above the patient's head. Instraments (exoph-
thalmometers) have been devised for the measurement of the
amount of protrusion, and of these Hertel's is one of the best.

The causes of true exophthalmos are : increase in volume of the
orbital contents, or diminution in the capacity of the orbit. The
prominence of an enlarged eyeball due to high myopia, or to anterior
staphyloma, as also the slight degree of exophthalmos w^hich results
from relaxation or loss of tone in the orbital muscles when several
of them are simultaneously paralysed, are not reckoned as true
exophthalmos. Again, the physiological forward position of the
eyes sometimes present in very stout persons must not be misin-
terpreted. Eetraction of the lids which follows the use of cocaine,
and w^hich also occurs in the early stage of exophthalmic goitre, and
in other conditions (p. 622) may produce the appearance of proptosis,
without any real displacement of the eyeball.

True exophthalmos from increase in the orbital contents may
be brought about by inflammatory exudation, as in orbital cellulitis,
by new growths, by vascular diseases such as arterio-venous

^ TT/so, forwards ; Trrwcrts, faUing.
596

CHAP. XX.] THE ORBIT. 597

aneurism and cavernous sinus thionibosis, and hv haemorrhage
or emphysema, the result of injury. Diminution in the capacity
of the orbit as a cause of exophthahnos is most commonly due to
encroachment on it from disease of the nasal sinuses and in rare
cases to the condition known as Tower Skull (oxycephaly) and the
still more rare affection Leontiasis Ossium. Exophthalmos is most
frequently met with as a unilateral affection, but it may be bilateral,
as in exophthalmic goitre, in the later stages of thrombosis of the
cavernous sinus, in pansinusitis, and also in symmetrical tumours
of the orbit (lymphoma).

Orbital Cellulitis. — The Sym-ptoms of this affection are : ery-
sipelatous swelling of the lids, especially of the upper lid ; serous
chemosis ; pain in the obit, increased on pressure of the eyeball
backwards ; violent facial neuralgia ; exophthalmos, with impair-
ment of the motions of the eye in every direction ; and high fever,
sometimes with headache and vomiting.

Vision is not generally affected, except when accompanied by
optic neuritis, and then, too, mydriasis is seen. The cornea is
often completely or partially anaesthetic.

The surgeon, by pressing the tip of his fourth finger between the
eyeball and the margin of the orbit, may feel a more or less resistant
tumour. This gradually increases in some one direction, the integu-
ment in that position becomes redder, fluctuation becomes pro-
nounced, and the abscess finally opens through the skin, or into the
conjunctival sac, the pointing being usually at the upper and inner
angle of the orbit. Restoration to the normal state, as a rule, comes
about ; but in some cases complete atrophy of the optic nerve
supervenes. Other cases, however, recover without the formation
of pus ; while again, thrombosis of the cavernous sinus, or even
meningitis or cerebral abscess may ensue.

In panophthalmitis (p. 192), as in orbital cellulitis, exophthalmos,
loss of movement, swelling of the lids and chemosis also occur, but
in panophthalmitis these symptoms are preceded and accompanied
by purulent irido-cyclitis, or by suppuration of the cornea.

Causes. — (1) Idiopathic [e.g. cold) ; (2) traumatic (perforating
injuries, foreign bodies) ; (3) extension of inflammation from sur-
rounding parts (erysipelas, diseased tooth, ethmoidal cells) ; (4)
metastasis (pytemia, metria) ; (5) sequela^ of fevers (scarlatina,
typhoid, purulent meningitis, influenza). The majority of cases of

598 DISEASES OF THE EYE. [chap. xx.

orbital cellulitis are due to infection from the neighbouring sinuses.
The frontal sinus is the one most frequently affected, the anterior
ethmoidal and maxillary antrum coming next in order of frequency.
Treatment. — Locally, poultices or warm fomentations ; and,
when pus has formed, its earliest possible evacuation by a deep
incision usually close to, and parallel to, the inner wall of the orbit,
followed by drainage and cleansing of the cavity with hydrogen
peroxide or antiseptic solutions. Even in the earlier stages, if there
be much swelling and exophthalmos, these deep incisions should
be made to relieve the tension, and allow the pus, if it does form, to
find its way more readily to the surface. The nasal sinuses should
be treated if necessary by endo-nasal or radical methods. We have
seen cases in an early stage yield to non-operative endo-nasal
treatment. The general constitutional treatment suitable to each
case need not be discussed here.

Tenonotis, or Inflammation of the Capsule of Tenon, is an uncommon
affection, the symptoms of which are those of a moderate celhihtis of the
anterior part of the orbit. As in orbital celluHtis, the hds are red and
swollen, there is slight exophthalmos, with restricted mobility of the eye,
and chemosis, but no conjunctival discharge. The diagnosis (as distin-
guished from cellulitis) rests on the slight degree of exophthalmos, as
compared with the great loss of mobility, and relatively well-marked
chemosis. In the early stage, before the inflammatory symptoms have
declared themselves, the patient complains of periorbital neuralgia, fol-
lowed by a sense of pressure in the eye, and great pain on attempting to
move it, so much so that the eyes are kept closed and immovable. One
or both eyes may be affected, and relapses are common. Vision is not
affected and febrile symptoms are much milder than in cellulitis. The
prognosis is good, recovery taking place in about a week. Sometimes
suppuration occurs, and a small sub-conjunctival abscess forms, which
generally opens upwards and inwards. In addition to the serous and puru-
lent varieties, a chronic plastic form of the disease has also been met with.

Causes. — Chronic rheumatism (sometimes with effusion into a joint),
influenza, and in rare cases tuberculosis. The suppurative form may be
traumatic, or may follow measles or scarlatina.

Treatment. — A^^arm fomentations, and a light bandage, with salicylate
of soda, antipyrin, or quinine internally.

Thrombosis of the Cavernous Sinus gives rise to symptoms
which may be mistaken for those of an orbital process. It fre-
quently spreads to the opposite side, and is accompanied by cerebral
symptoms. The affection is described at p. 502.

Periostitis of the Orbit. — Acute periostitis of the orbit has many

CHAP. XX.] THE ORBIT. 599

symptoms in common with phlegmonous inflammation of the orbital
connective tissue, which generally accompanies it, but it may
usually be distinguished from the latter inflammation occurring in-
dependently, by the fact that, in it, pressure on the orbital margin
is painful. The absence of this tenderness, however, is not always
conclusive of the absence of periostitis, especially when the latter
is restricted to the deep parts of the orbit. In periostitis the eye-
lids are not usually so swollen as in inflammation of the orbital
tissues. Suppuration may take place, necrosis in consequence of
detachment of the periosteum may come on, and communications
with the neighbouring cavities may be formed.

In secondary syphilis, or in later stages of the disease, a syphilitic
gumma of the orbital wall may form. This is accompanied by
violent frontal neuralgia or headache, increasing at night. Proptosis
occurs, with marked loss of motion in the eyeball in one or more
directions. This early loss of motion is a very characteristic symp-
tom, and serves to assist in the diagnosis between gumma and
other orbital tumours. It is probably due to an extension of the
inflammation to the connective tissue of the orbit, and to the muscles
themselves.

The symptoms suggestive of gummatous periostitis of the orbit
are : — A rapidly increasing proptosis, wdth displacement of the globe
downwards and forwards, and much loss of motion of the eye, while
on palpation the sensation is given to the finger of a tumour in the
roof of the orbit, ^vhere gummata most commonly are situated.
Also, thickening of the upper margin of the orbit, with pain on pres-
sure on the roof of the orbit, and radiating periorbital pain at night.
Periostitis of a chronic form, and without tendency to suppura-
tion, occurs most commonly in persons with a constitutional rheu-
matic tendency. It is accompanied by pain in and about the orbit,
with increased tenderness on pressure backwards of the eyeball.
Exophthalmos, and all other outward signs, are usually wanting.
The Profjnosis depends much on the seat of the inflammation.
If this be in the deep parts of the orbit, thickening of the periosteum
may cause permanent protrusion of the eyeball ; extension of the
inflammation to the optic nerve may result in optic atrophy ; the
orbital muscles, or the nerves which supply them, may be implicated,
with consequent paralysis ; or, finally, the inflammation of the
periosteum may strike into the meninges of the brain. When the

600 DISEASES OF THE EYE. [chap. xx.

inflammation is near the margin of the orbit, early evacuation of pus,
if it have formed, reduces the process within safe bounds ; and this
position is one of less danger in respect of its surroundings, than if
the process be deep in the orbit.

Causes. — Periostitis of the orbit may be caused by blows or other
traumata, by extension from neighbouring cavities, by syphilis, or
by rheumatism.

Treatment. — Warm fomentations. Exit given to pus, if possible.
Constitutional treatment. Incision along the orbital margin, and
separation of the periosteum, with drainage, may shorten the pro-
cess, if the foregoing measures do not give relief.

Caries of the Orbit is very frequently the result of periostitis,
but often commences in the bone, and in either case is usually due
to tubercular disease. It is also seen in very late syphilis. A
trauma is sometimes the immediate cause of its onset.

Caries may attack any part of the orbital walls, its favourite
seats being the margin above and to the outside, or below and to
the outside. The latter situation is a common one for tubercular
disease. When it is seated deeply in the orbit, it often causes ex-
ophthalmos and pain. At the margin of the orbit it produces oedema
and swelling of the eyelids, with conjunctivitis ; suppuration comes
on, and the abscess finally opens through the integument or con-
junctiva. A fistula is apt to remain for a length of time, and, the
skin being drawm into this, ectropion of the lid is produced. If a
portion of dead bone come away, the resulting cicatrix is liable to
maintain the ectropion (p. 574).

Treatment. — The evacuation of purulent collections at the earliest
possible moment — if they be deep in the orbit, by the careful in-
troduction of a long bistouri parallel to the orbital wall — the in-
sertion of a drainage-tube, and the regular washing out of the
cavity with antiseptic solutions, until no more rough or bare bone
can be felt with the probe. If the case be very tedious, Kronlein's
operation may permit of the removal of sequestra with greater
ease and security.

Injuries of the Orbit.— Wounds of the soft parts in the supra-
orbital region, involving the supra-orbital nerve, were formerly
held to be capable of producing a reflex amaurosis (p. 391), and
many such cases have been recorded under the name of supra-orbital
amaurosis. But the blindness in the cases recorded was brought

CHAr. XX.] THE OIUilT. m\

about in some other way — c.q. injury to the optic nerve in the optic
foramen by the concussion, or by a fracture of the margin of the
foramen, orbital periostitis, concomitant injury to the eyeball itself,
facial erysipelas, intracranial lesions, and so on.

It may be, however, that a functional amblyopia, or amaurosis,
similar to that occasionally seen after long-continued blepharospasm
(p. 105), has sometimes been present.

Perforating injuries, more especially of the roof of the orbit
through the eyelids, by prods of walking-canes, etc., and the lodgment
of foreign bodies in the orbit are serious accidents. They are liable
to be followed by phlegmonous inflammation ; or, if a pointed
weapon (stick, sword-cane, etc.) has been pushed into the orbit with
some force, it may divide the optic or motor nerves, or injure the
muscles, or it may even pass through the bony wall and perforate
the brain, with fatal result.

It is remarkable what large foreign bodies may be concealed in
the orbit. We have removed large pieces of wood, which had lain
in the orbit, in one case for weeks, in another for several months
without inflammatory symptoms. In the first there was even no
exophthalmos.

Haemorrhage into the Orbit may occur from injury, and may
cause exophthalmos, or atrophy of the optic nerve from pressure.
Such orbital haemorrhages are sometimes met with at birth, as the
result of complicated labour, especially when the forceps has been
applied. Spontaneous haemorrhages have been observed in old
people with diseased arteries, in whooping cough, in haemophilia,
and in haemorrhagic small-pox ; and sub-periosteal haemorrhages
occur in Barlow's disease.

Haemorrhage in the Eyelids, with ecchymosis of the conjunc-
tiva, commonly known as a black eye, is usually the result of blows
with large blunt objects, such as the closed hand. The object which
causes the injury is arrested by the margin of the orbit, against
which the tissues are bruised, while the eye usually escapes. On
the other hand, when the object is small or sharp, it enters the orbit,
and injures the eyeball, and there is less tendency to external
bruising.

Deep Fractures of the Orbit, in the neighbourhood of the optic
foramen, may cause atrophy of the optic nerve without any other
symptom. The atrophy may not appear for some weeks, hence

602 DISEASES OF THE EYE. [chap. xx.

the necessity for a cautious prognosis in cases of head injuries.
Where the optic atrophy is the result of haemorrhage into the
sheath of the optic nerve, a dark greyish red ring may be visible
round the margin of the optic papilla.

Emphysema of the orbit, or of the lids, or of both, sometimes
occurs from injury of the ethmoid, or from rupture of the mucous
membrane of the lacrimal duct. The emphysema develops after the
injury when a strong expiratory effort, such as blowing the nose,
is made. Emphysema also occurs in perforation of the ethmoid
from disease, and even, although rarely, without previous disease.

Treatment. — Foreign bodies should be removed by dilatation
of their wounds of entrance, or by the formation of a new passage
through the conjunctival fornix — and great care should be taken
to prevent the onset of inflammation, or to keep it within safe
bounds. A pressure bandage, and the exercise of caution when
blowing the nose for a little while, is all that is required in emphy-
sema.

Enophthalmos, or sinking of the eye back into the orbit, ^A'ith
apparent narrowing of the palpebral fissure, occurs to a certain extent
in extreme emaciation, in Asiatic cholera, in paralysis of the S3^mpathetic,
and in facial hemiatrophy. But it has been observed to an extreme
degree as a result of blows on the eye, or on the lower orbital margin
(Traumatic Enophthalmos) ; and in these cases atrophy, or cicatricial
contraction of the retrobulbar cellular tissue, or paralysis of Miiller's
muscle, from injury of the sympathetic nerve, have been held accountable
for the condition. In some cases, it is due to fracture or depression of a
portion of the orbital wall.

Enophthalmos is sometimes congenital ; it is also present, occasionally
in intermittent exophthalmos (p. 609), when the patient is in the erect
position, and after removal of retrobulbar tumours.

* Tumours of the Orbit.— In the Diagnosis of an Orbital Tumour
three questions present themselves :— First, Is a tumour of the orbit
present ? Secondly, Is the new growth confined to the orbit, or
does it extend to neighbouring cavities ? and Thirdly, Of what kind
is the new growth '! The diagnosis as regards any of these points
does not often occasion much difficulty in advanced stages of the
disease, especially where the growth occupies the anterior part of
the orbit, or protrudes from it. It is rather in the early and middle
stages that difficulties in diagnosis present themselves, and attention
will here be mainly directed to those stages.

CHAP. XX.] THE ORBIT. 003

Exophthalmos is, of the signs by wliich the presence of an oilntal
tumour is diagnosed in its early stages, by far the most important,
because it is the most constant. In the earliest stages of a growth
which commences in the deepest part of the orbit there may be, it
is true, no exophthalmos, while other symptoms — defects of sight,
pain, loss of motion — may already be present ; but when the growth
attains to certain dimensions, or if in the anterior part of the orbit
there be even a small tumour, the eyeball must be pushed out of
its place.

An important diagnostic point in connection with the exophthal-
mos caused by a tumour is that, unless it be within the muscular
cone, its direction is almost always oblique and not straight for-
wards ; for orbital tumours commonly tend to develop more along
some one w^all of the orbit than along the others, and hence the
eyeball becomes pushed towards the opposite side as well as for-
wards. In cellulitis, a?dema of the orbital tissues, Graves' disease,
and paralytic proptosis, the exophthalmos has a direction straight
forwards. Tumours growing from the apex of the orbit may, in
their early stages, cause no obliquity of direction in the displace-
ment of the globe, and some tumours do not do so even in an ad-
vanced stage of their growth ; but these cases are exceptional.
Tumours, too, situated altogether within the muscular cone, of
wliich the most common are tumours of the optic nerve, need not
cause any lateral displacement of the globe.

Again, the exophthalmos caused by an orbital tumour usually
increases in degree slowly and gradually, differing in this respect
from exophthalmos due to most of the other causes, in which either
a sudden or a rapid development of the proptosis is the rule.

While tumours are sometimes present in both orbits, especially
lymphoma or lympho-sarcoma, yet it is infinitely more common for
one orbit alone to be diseased ; and hence monolateral exophthalmos
is suggestive of orbital tumour.

Palpation in the Orbit often provides a valuable sign, should the
new growth have come within reach in the anterior part of the
cavity. In many cases, indeed, there is no difnculty whatever in
recognising the presence of an orbital tumour, by this means, the
sensation obtainable by the tip of the surgeon's finger pressed into
the orbit being very definite ; in some the tumour can only be felt
when the patient is ana3stlietised ; but in other cases the evidence

604 DISEASES OF THE EYE. [chap. xx.

is not so clear, and a reasonable doubt may exist as to whether any
abnormal resistance is met with. By palpation we may gain some
knowledge of the position, extent, shape,, and consistence of the
tumour, and whether it be adherent, either to the walls of the orbit
or to the eyeball. It is important, when practicable, to compare
the result of examination of the diseased orbit with the condition
of the sound orbit ; and this can be done to greater advantage if
palpation of the orbits be performed simultaneously with a finger
of each hand.

Radiography has been successfully employed in some cases for
the diagnosis of retrobulbar growths.

Derangements of Vision are often, but by no means always,
present in the early and middle stages of the growth of an orbital
tumour. Their occurrence depends frequently on the rapidity of
the growth of the tumour, rather than ujDon its size. In an early
stage of a rapidly increasing tumour, the sudden stretching of, and
pressure on, the optic nerve may produce absolute blindness ;
while in another case, with an equal degree of proptosis, but which
has been brought on by a slowly growing tumour, vision may be
unaffected, by reason of the optic nerve becoming gradually ac-
customed to the change. Yet slowly growing tumours, which
spring from the optic nerve or its neighbourhood, or from the deepest
part of the orbit, are competent, by direct pressure on, or by implica-
tion of the optic nerve, to cause serious loss of sight, even in an
early stage, and with but little exophthalmos. Optic neuritis, and,
later on, optic atrophy, are occasionally discovered with the ophthal-
moscope. Diplopia is often present when the globe is at first
displaced, but disappears when the exophthalmos becomes extreme
or the vision defective.

Pain is a symptom sometimes, but by no means always, present
in cases of orbital tumours. It is especially liable to be complained
of when the growth is increasing rapidly in size, even though it may
not have attained to great dimensions. The pain is then often of
a neuralgic kind, and very severe, from the unaccustomed pressure
on branches of the fifth nerve in the orbit.

Loss of Power of Motion of the Eyeball is a very cammon symp-
tom in cases of orbital tumours. It is caused in some cases by the
mechanical ol)struction offered by the tumour, as a result of which
motion of the eyeball becomes defective towards the side of the orbit

PHAr. XX.] THE ORBIT. 00".

on \yhicli thi' lu-w growth is situated. In other cases the loss of
motion is caused by stretchini^ of the muscles from the exophthalmos,
or ])y implication of IIkmii in the new growth, or by atrophy of
their tissue, or by paralysis of the orbital nerves from pressure.

When there is little or no loss of motion, while the proptosis is
marked, the conclusion wvav be drawn that the tunioui- lies within
the nuiscular cone.

In the later stages the exophthalmos may become so great that
the eyelids no longer cover the eyeball sufficiently, and a purulent
keratitis may set in which may end in loss of the eye. The bulbar
conjunctiva below the cornea becomes cedematous, bulges forwards,
and becomes covered with crusts, and the lower lid becomes
everted.

In every case the history, the rapidity of growth, and the age
and general condition of the patient are important items for con-
sideration.

Diagnosis of the Nature of an Orbital Tumour. — As regards the
nature of the growth which may be present, it must be admitted
that in many instances, in the early stages of a deeply seated tumour,
we have to rest content with an indefinite or provisional diagnosis,
unless an exploratory operation, such as aspiration, or harpooning
of the mass, is practicable.

Primary tumours of the orbit may be conveniently described
under the following heads : — Cysts, solid tumours, pulsating ex-
ophthalmos, symmetrical tumours, tumours of the optic nerve, and
tumours of the lacrimal gland.

Orbital Cysts are usually congenital (Dermoids, Encephalocele,
Serous), but may be acquired (Hydatid, Cysticercus).

Dermoid Cysts are those most frequently found. Although
congenital, they do not often grow to any size until the age of
puberty or later, and may then for the first time give rise to trouble-
some symptoms. They are smooth rounded tumours which grow
slowly, and finally reach very considerable size, and then bulge out
between the eyeball and margin of the orbit. Pressure upon this
protruding part causes it to diminish, while the exophthalmos is at
the same time increased, and distinct fluctuation in the protruding
part can be felt. The growth of the cyst is unaccompanied by pain
or other inconvenience. It may adhere to the periosteum and cause
bony irregularities, or even perforate the loof of the orbit. The con-

000

DISEASES OF THE EYE.

[chap. XX.

tents are generally either serous or honey-like, and occasionally hairs
and other epidermic formations have been found in them.

Hernia Cerebri, cither in the form of meningocele or of encephalocele,
may invade the orbit. Its most common situation is the upper and inner
angle of the orbit, to which it gains access through the suture between
the frontal and ethmoid bones. It appears as a fluctuating, often trans-
parent, pulsating congenital tumour. Sometimes the opening in the bones
can be felt around its base. Pressure upon it causes it to disappear, but
gives rise, at the same time, to symptoms of cerebral irritation, or pressure.

A congenital tumour in the
upper inner angle of the orbit
must be regarded with sus-
picion, lest it be a cerebral
hernia, even though it do not
pulsate, or on pressure cause
cerebral symptoms. In the
large cerebral hernise, death in
the first few days of life is the
rule.

Cysts with Anophthabnos. —
These appear as serous cysts,
which project into the lower
lid, giving it a slightly bluish
tinge. They are associated
with so-called anophthalmos
(Fig. 255), in which, in spite
of the name, a small or rudi-
mentary eyeball is always
found. The cavity of the
cyst frequently communicates
with the interior of the eye,
and contains retina more or less altered and thrown into folds. These
cases are regarded as encysted colobomata (p. 223). Other cases are
believed to arise from foetal inclusion of a portion of the lacrimal sac.

Parasitic Cysts are usually caused by the echinococcus, while the cysti-
cercus is much rarer in the orbit. Several cases of the former have been
observed in England. The cysts are generally deeply situated, and the
first symptom is severe pain in the head, like hemicrania. Their growth
is very slow, and the presence of a hydatid thrill is very rare. The fluid
obtained by aspiration may contain booklets or scolices.

Treatment. — The cyst should be removed in toto, if possible.
For this purpose, Kronlein's operation (p. 618) may be resorted to.
Or, a horizontal incision may be made along the orbital margin
through the eyelid, in order that the cavity of the orbit may be
reached ; or two perpendicular incisions at either canthus through
the upper lid may be made, and the latter turned upwards. With

Fig. 255. — A case of so-called anoph-
thalmos, with a cyst in the left
lower lid.

CTTAr. xx.l THE ORBIT. 007

liooks oi luiTcps, and sc;i1i)l'1 or scissors, the cyst wall must then l)e
caiefullv separated from all adhesions. If it cannot be removed
entire, as large a portion of the wall as possible should be taken
away, and the contents evacuated by gentle pressure backwards of
the eyeball, and the sac washed out two or three times daily with
an antiseptic solution, until all discharge has ceased. The above
treatment does not, of coui'se, a])])ly to encephalocele. which should
not be interfered with.

Solid Tumours of the orl)it are in most instances malignant
(sarcoma, endothelioma), but may be benign (exostosis, angioma,
fibroma). They vary in consistency from the softness of the angio-
mata, to the dense hardness of the ivory exostoses.

Exostoses occur as the result of faulty development of the bones,
and also without any apparent cause, and are usually of the kind
known as ivory exostoses. Three-fourths of them begin before the
twenty-fifth year of age. They spring most commonly from the
ethmoid or from the frontal bones, especially tjie frontal sinus, and
have a broad base, but are sometimes pedunculated.

All the bony tumours give, of course, the sensation of dense
hardness to the touch ; but there are some malignant growths of
such hardness that it may not be easy to tell them from the osteo-
mata by palpation. And here a Kontgen ray examination will be
necessary. The growth of an orbital osteoma is excessively slow,
in many instances commencing in infancy, and lasting into advanced
life. In addition to the dense hardness of these tumours, the de-
ciding points in the diagnosis are their smooth, usually globular,
and somewhat nodulated surface, along with their immobility, and
direct connection with the walls of the orbit, all ascertainable by
the touch.

Operative interference, in cases of exostosis of the orbit, is only
justifiable when the tumour does not grow from the roof of the orbit
(as it then often involves the cranial cavity), and when there is
reason to think that it is attached to the orbital wall by a narrow
base or pedicle. Several instances are on record in which the growth
has become spontaneously separated by necrosis of its pedicle. Be-
yond destruction of the eyeball there is no danger associated with
these tumours, even if their growth take an intracranial direction ;
but they cause serious disfigurement, and often much pain.

Angiomata may be simple or cavernous. They are usually soft,

008 DISEASES OF THE EYE. [chap. xx.

comjn'essible, and painless, are very slow in their growth, and do
not give rise to pulsation or bruits. The teleangiectases, or simple
tumours, are usually congenital, and are often merely extensions into
the orbit of angiomata of the eyelid. The cavernous form is often
encapsuled. A few cases of lymphangioma have also been met with
in the orbit.

Sarcoma. — Malignant tumours of the orbit are nearly always
sarcomata, many different varieties of which are met with. Sarcoma
may develop in the connective tissue in any part of the orbit, most
frequently, perhaps, in the periosteum and in the connective tissue
about the lacrimal gland. Or it may arise from the endothelium of
the vessels (endotheliomata), and if very vascular, it may pulsate,
but without a murmur. These malignant tumours, after destruc-
tion of the eyeball by pressure, or by phthisis following ulceration of
the cornea, attack the bony walls of the orbit and its surroundings.

The early extirpation of the tumour with complete evisceration
of the orbital contents affords the only prospect, and that a slight
one, of saving the patient's life.

Some forms of sarcoma, however, are non-malignant, especially
those which lie free in the orbit and arise from the connective tissue.
Indeed, Panas held that many cases of sarcoma, as also of lymphade-
noma of the orbit, are due to infectious principles, toxins, or microbes,
and are amenable to medical treatment by mercury, iodine, arsenic,
or toxitherapy. So much certainly must be admitted — namely, that
cases now and then present themselves, with all the signs and symp-
toms of orbital tumour, which ultimately undergo a purely spon-
taneous cure, or one unexpectedly brought about by iodide of
potassium.

In some of these cases of pseudo-tumour no tumour is found
in spite of the existence of exophthalmos, etc., while in others a
chronic inflammatory condition of the connective tissue alone exists,
which may be syphilitic or tubercular. We have ourselves seen a
large sarcoma-like orbital tumour, which, on removal, proved to be
merely a mass of inflammatory tissue.

Carcinoma of the orbit, unless originating in the lacrimal gland, is
always secondary to carcinoma elsewliere in the body. Paralysis of the
external rectus may be an early result of such a growth. We have seen
it occur after removal of a carcinoma of the breast.

Symmetrical Tumours of the Orbits. — With the exception of tumours
of the lacrimal glands, and possibly of rare instances of metastatic tumours,

Chap, xx.j THE ORBIT. (ioO

symmetrical tumours of the orbits are almost invariably lymphoraataor
lymph-adenomata, occurring in leucieniia or in psoudo-leucasmia.

Pulsating Exophthalmos. — Tliis is most frequently due to arterio-
venous aneurism in the cavernous sinus, which may })e either trau-
matic or spontaneous. The symptoms are : proptosis ; the presence
of peculiar bruits, usually continuous but with systolic reinforce-
ment, which can be heard with the stethoscope over the orbit,
and usually, also, over a more or less extensive portion of the
skull ; engorgement of the veins of the eyelids ; pulsation, apparent
in the eyeball, or at some point of the orbital aperture, and often a
thrill which can be felt with the fingers placed on the upper lid.
The pulsation and thrill may be diminished or abolished by pressure
on the common carotid. The two latter symptoms are occasionally
absent during the whole, or part, of the progress of the case. Para-
lysis of the ocular muscles, most commonly of the external rectus,
often occur. There may be retinal venous engorgement or even
papillitis with defective vision. The same symptoms may be
exceptionally caused by aneurism of the carotid in the cavernous
sinus, aneurism of the ophthalmic artery at its origin or in the orbit,
and by cirsoid aneurisms, or by very vascular malignant tumours.
It is also possible that obstruction of the cavernous sinus from other
intracranial causes may produce these symptoms.

Haemorrhage is liable to prove fatal in these cases.

Treatment. — Ligature of the common carotid affords the best
prospect of cure. Digital compression of the same vessel has pro-
duced cure in some cases. Spontaneous cure has been observed
occasionally in cases of arterio-venous aneurism.

Intennittent Exophthalmos. — This is due to a varicose condition of tlie
veins of the orbit. The exophthalmos only occurs on stooping, or on
exertion, and can be produced by compression of the jugular vein in the
neck. In the erect position there is often enophthalmos. Sometimes
dilated veins are visible in the eyelids. In a case which we have recently
seen the tendency to exophthalmos was kept in check by the wearing of
a bandage at night.

Tumours and cysts of the lacrimal gland also occur in tlie orbit (see
p. 533).

Tumours of the Optic Nerve. — These are rare affections. They occur
at ail times of life, but the majority of the patients are under twenty years
of age. The tumour usually commences about the middle of the course
of the nerve, and does not reach the bulbar end. The symptoms are : —
Slowly increasing protrusion of the eyeball, in a direction most usually

GlO

DISEASES OF THE ^YE.

[CHAJP, XX.

Fig, 256. — Tumour of the
Optic Nerve.

directly forwards, or forwards and outwards (Fig. 256). The motions

of the eyeball are not greatly restricted, and the centre of its rotation is

not displaced, owing to the tumour being within the cone of the orbital

muscles. The proptosis is unaccompanied

fby pain. The sight becomes very defective,
or is quite lost at a very early stage, from
interference with the functions of the nerve
by the tumour or by the optic neuritis, or
optic atrophy, to which it gives rise. The
tumour is sometimes very soft, so that the
eyeball can, as it were, be pushed back into

it, and the pressure does not cause pain.
The pupil reacts consensually. The tumour
may often be felt by palpation in the orbit.
The patient's health does not suffer.

The diagnosis between a new growth of
the optic nerve and one of its sheath can
hardly be made with certainty ; but the
existence of fairly good vision, while other
symptoms are as above described, long after
the proptosis has appeared, would point to
the sheath as the seat. Such a diagnosis is important, for it may be
possible to remove, by Kronlein's operation, a tumour of the sheath of
the optic nerve, while jDreserving not merely the eyeball, but good vision
as well.

These tumours are either fibro-sarcomata (fibromatosis), or, less fre-
quently, endotheliomata, and are usually intra-dural, i.e. encapsuled by
the sheath of the nerve. Extra-dural tumours are more rare. Both
varieties are benign, in the sense that they do not lead to glandular en-
largements or to metastases, and they never
spread to the eyeball although the extra
dural tumours often surround the posterior
half of the globe ; but in some cases death
occurs from extension of the disease to the
cranial cavity, or from the sudden develop-
ment of intracranial growths, which co-
existed with the optic nerve tumour. An
intracranial complication may occur many
years after removal of the tumour of the
nerve. Local recurrence is less common, but
in one case a recurrence took place in the
orbit twenty-six years after operation.

Treatment. — To remove these tumours
three methods are available, namely: — (1)
Removal of the eyeball with the tumour ;
(2) Kronlein's operation, by means of which
the optic nerve tumour, probably in the
majority of cases, may be removed without the eyeball ; and (3) Knapp's
operation — also for removal of the tumour without the eyeball. It is

Fig. 257. — The same
patient as in Fig. 256 after
Kronlein's operation.

GHAP. XX.] THE ORBIT. 611

unnecessary to describe the first of these procedures, which follows
very much the lines of an ordinary excision of the eyeball, except that the
optic nerve is divided as far back in the orbit as possible. Kronlein's
operation is described on p. 618.

Knapp's operation is as follows : — The tendon of the internal rectus is
divided so as to leave a portion adherent to the sclerotic of about 5 mm.,
the cut end being secured by a suture passed through it, to prevent it from
retracting into tlie orbit. The eyeball is then forcibly everted outwards,
strong scissors are passed into the orbit, and the optic nerve is divided
as close to the optic foramen as possible. The globe is now further everted
outwards, to expose its posterior surface with the tumour attached, and
the latter is removed by dividing the optic nerve close to the eyeball.
Finally, the eyeball is reposed, the cut ends of the tendon of the muscle
united, and the opening in the conjunctiva closed. A drawback to this
operation is, that it is not always possible to be certain that the deep
portion of the tumour is reached with the scissors.

Lagrange passes a ligature or loop over the tumour, divides the nerve
as far back as possible, draws the tumour out, and thus exposes the back
of the eyeball, from which the tumour is then removed. Fig. 256 repre-
sents a case of tumour of the optic nerve and Fig. 257 the same case after
operation by Kronlein's method.

Implicatiox of Neighbourixg Cavities. — As regards the
question whether the tumour be confined to the orbit, or involve one
or more of the neighbouring cavities, it may be assumed that it is
confined to the orbit, unless there are symptoms or signs which point
in the opposite direction ; and in each case these symptoms and signs
ought to be sought for. Tumours may either originate in one of
the spaces and grow into the orbit, which is the more common event ;
or, originating in the orbit, they may spread to a neighbouring
space ; and it is often the history or progress of the case alone that
can inform us which of these events has taken place.

When disease (mucocele, empyema, tumour) of the accessory
sinuses of the nose involves the orbit, the symptoms which ensue
may be due to the effect of the pressure exerted by the over-dis-
tended sinus, or to septic infection, or to a combination of these.
The pressure effects are produced by the formation of a tumour-like
projection of some portion of the orbital wall corresponding with
the position of the affected sinus. This leads to displacement of the
eyeball with exophthalmos and limitation of movement, and the
sight may be impaired or lost from optic neuritis, or from atrophy
of the optic nerve. If the sphenoidal, or posterior ethmoidal sinus
be diseased, impairment of vision in one or both eyes may be the
only symptom in the early stage. This is due to the fact, that the

G12 DISEASES OF THE EYE. [cha?. ^^.

inner boundary of the optic canal sometimes forms a portion of

the wall of these sinuses, and may be extremely thin on one or both
sides, thus rendering the optic nerve particularly vulnerable. The
nerve generally shows signs of inflammation or atrophy, but on the
other hand it may be normal, as in retrobulbar neuritis from other
causes (p. 347), and the defect of vision may only reveal itself as a
central scotoma, or as an enlargement of the blind spot.

If septic infection take place, orbital cellulitis and its conse-
quences (p. 597) result. Infection is usually preceded by perforation
of the orbital wall, but it may be carried into the orbit by emissary
veins, or through small foramina, or congenital dehiscences in the
bony walls.

Mucocele or empyema is sometimes indicated by a history of
influenza, or post-nasal catarrh, followed by purulent discharge
from the nose. In all cases, a careful examination of the nose
ought to be made, aided, if necessary, by transillumination and
radiography. It should be remembered, however, that empyema
of a sinus, with implication of the orbit, may sometimes exist without
any appearance of nasal disease, if the channel of exit from the sinus
be completely occluded.

In general, it may be stated that inflammation of the frontal and
anterior ethmoidal sinuses gives rise to cedema and swelling of the
lids, periostitis of the orbit, or peri-dacryocystitis ; while disease
of the posterior ethmoidal and sphenoidal sinuses is more apt to
cause retrobulbar neuritis, optic neuritis or atrophy, or paralyses
of orbital muscles.

The Frontal Sinus. — This sinus begins to form at about the
seventh year of age, and continues to increase in size from that
time onwards. Disease of this sinus, therefore, is only met with
in adults. It frequently extends to the ethmoid, and sometimes
leads to maxillary empyema. There may be some redness and
swelling at the inner extremity of the eyebrow, with tenderness
on percussion, and the patient sometimes suffers from paroxysmal
attacks of frontal neuralgia, often worse in the morning ; but again
in this, as in the case of other sinuses, the pain may be diffuse,
and not in any way characteristic. (Edema of the upper lid may
be the only symptom of a frontal sinusitis. We have been con-
sulted by patients, in one case for an oedema of the upper lid, and
m another for morning ptosis, and in both cases the symptoms

CHAP. XX.]

THE ORBIT.

613

were the result of frontal sinus disease. A tumour then forms at
the upper and inner anpjle of the orbit, and displaces the eye down-
wards and outwards. In some cases a fistula appears above the
position of a lacrimal sac, and fluid may appear in the nostril
on syringing it. Rarely, a frontal mucocele may form a sub-
periosteal collection in the roof of the orbit, and point at the outer
side of the latter. Osteoma of the frontal sinus shows itself as a
slowly growing and densely hard tumour, almost free from pain,
situated along the superior margin of the orbit, extending into the
latter and pushing the eyeball downwards and forwards. It may
subsequently extend to the orbital plate of the ethmoid, and may
be mistaken for an exostosis of the orbit. Bony growths originating
in the orbit may invade the frontal sinus, and, whether originating
there or in the sinus, are liable to produce absorption of the tables of
the skull without any cerebral symptoms to indicate the occurrence.
The Ethmoid Cells. — Tumours of these cells, which encroach
upon the orbit, are likewise most commonly either mucocele (em-
pyema) or osteoma. Mucocele of the ethmoid cells presents itself
in the orbit, as a smooth hard tumour,
on the inner wall of the orbit, giviiiu
rise to displacement of the lacrimal
bone (with, perhaps, a sense of fluctua-
tion and crepitation on palpation),
and pushing the eyeball outwards and
forwards. Epiphora may be an early
symptom. There is sometimes a feel-
ing of pressure on the bridge of the
nose. Nervous symptoms, such as
mental dullness, hypochondriasis, etc..
may be present. Mucocele of the
ethmoid cells encroaching on the orbit
must also be distinguished from a der-
moid cyst (p. 605). Osteoma of the

ethmoid appears in the orbit as a hard round swelling at the
inner canthus, followed by a swelling of the cheek and displace-
ment of the eye outwards and forwards. It is apt also to extend
into the nasal meatus, displacing the septum, and pushing the hard
palate downwards, so that examinations of the nose and of the
mouth should be made in aidjof the diagnosis. Enchondromata

Fio. 25S. — Anterior Ethmoi-
dal Mucocele.

614 DISEASES OF THE EYE. [chap. xx.

and fibromata, too, sometimes spring from the ethmoid, and extend
into the orbit, and malignant growths may be met with here.

The Sphenoid Bone and Antrum of the Sphenoid. — Tumours
originating here and encroaching upon the orbit are rare, and
the diagnosis of their origin in an early stage may be impossible,
except by radiography. They may cause pain in the occipital
region, and, as stated above, optic atrophy may be an early symptom.
It is said (Stedman Bull) that an orbital tumour which soon causes
blindness, commencing in the temporal side of the field, and leaving
the fixation point unaffected to the last, while at the same time a
growth appears in the naso-pharynx, is likely to be one having its
origin in the sphenoid antrum. Bony tumours — osteoma, hypero-
stosis, and exostosis — polypi, and sarcomata are the growths most
frequently found to originate in the sphenoid antrum.

The Maxillary Antrum. — Tumours of the antrum sometimes
push the floor of the orbit upwards, or erode it, and grow into that
cavity, driving the eyeball upwards and inwards, or upwards and
outwards. The breadth of the cheek is increased, the nose becomes
pushed towards the opposite side, and the roof of the mouth is
pushed downwards. Tumours of the antrum of Highmore some-
times cause pain in the teeth, or in the region of distribution of
the infra-orbital nerve, and there may be a dull pain in the region
of the antrum. In some cases there is a discharge of pus or of
blood from the nostril. Empyema of the antrum may give rise to
orbital cellulitis commencing at the lower part of the orbit, with
swelling of the lower lid, and chemosis of the conjunctiva below
the cornea.

We have seen two cases of malignant disease, one of the maxillary
antrum, and the other in the nasal fossa, in which epiphora was the
first symptom complained of by the patient.

Intracranial Tumours do not often invade the orbit. When
they do so they originate in the middle fossa, and gain access
through the sphenoid fissure and optic foramen. The diagnosis of
the origin of the disease can only be made, if cerebral signs or
symptoms, including defects in the field of vision, have existed prior
to any sign of a new growth in the orbit. Tumours of the pituitary
body may encroach upon the orbit by way of the sphenoid fissure, and
are apt to be associated with polyuria and bitemporal hemianopsia,
which assist the diagnosis.

CHAP. XX.]

THE ORBIT.

615

A more common event, although not in an early stage of the
growth, is the extension of a primary orbital tumour to the hrain,
either along the optic nerve, through the sphenoid fissure, or through
the roof of the orbit by erosion of the bone. This occurrence is
usually indicated by the presence of cerebral symptoms ; but cases
have been met with where no such symptoms existed, although
the orbital growth had encroached upon the anterior or middle
fossa of the skull.

Shrinking of the Conjunctiva (Xerophthalmos) and of the Sub-con-
junctival Tissue of the Orbit, subsequent to Enucleation of the Eyeball. —

111 some cases where the (>yel)all lias l)eeu excis(nl, and in chie course
a prothesis fitted, the conjunctiva and sub-conjunctival tissues shrink
to such a degree, after some months or years, as to reduce the size of the
orbital cavity so that the wearing of a glass eye becomes impossible.
This is especially liable to occur amongst those hospital patients who are
careless in removing the prothesis at night, and in keeping the socket
thoroughly clean at all times. The attempt is then often made to restore
the orbital cavity, so as to render it possible to wear at least a small
glass eye, by means of skin grafts, or of mucous membrane grafts, after
the method either of Thiersch or of Wolfe. The success attendant on
these procedures is usually a very moderate one, and often not permanent,
owing to subsequent renewed shrinking of the sub-conjunctival tissue.

In these cases the lower sulcus
is the most important part of the
cavity, and if it can be made
sufficiently deep, a small artificial
eye will be retained. This can be
done in certain cases by Maxwell's
method (Fig. 259).

An incision is made in the
floor of the socket, and carried
downwards behind the lower lid.
A semi-lunar flap, about 8 mm. in
width at its widest part, is marked
out on the skin of the lid, its
upper concave border being about
5 mm. below the palpebral margin.
The incision along the upper

border of the flap is made to communicate with the bottom of the wound
in the socket. The flap is now dissected up from the subcutaneous tissue,
except an area represented by the dotted line in Fig. 259. The two ends
of the flap {a' and h') are passed through the opening into the socket, and
sutured to each end of the socket incision (a and h) ; and the borders A'
and B' , being also passed through, are sutured to ^ and B respectively.
The space on the cheek is closed, and the operation completed by inserting
into the socket a temporary glass eye or shell. This should be as nearly

Fig. 259.

616 DISEASES OF THE EYE. [chap. xx.

as possible of the size and shape of the eye to be ultimately worn ; it
prevents the new sulcus from being obliterated by contraction, and gives
it a suitable shape. It cannot safely be taken out for at least a week, as
the skin incision might perhaps be opened in so doing. If there be secretion,
the space behind may be flushed out by a lacrimal syringe armed with a
fine curved nozzle, which can be introduced under the edge of the eye at
the inner or outer canthus. A glass shell with a hole in front is preferable
to a glass eye, for it allows a syringe to be more easily used, and, being
transparent, a view of the parts behind can be obtained.

To obtain a good result the following points should be attended to :
(1) Make the incision in the socket as long as the space will permit, and
see that this length is maintained throughout its entire depth. (2) Make
the skin flap considerably longer than the incision in the socket. (3)
When dissecting up the skin flap leave undisturbed a portion (dotted
line in figure) equal in length to the socket incision. This subsequently
forms the fornix, or sulcus. If a shorter portion be left, the sulcus is
apt to become V-shaped, which would require a specially made glass eye.
(4) When closing the space on the cheek, as the lower border is longer
than the upper, great care should be taken to equably distribute the excess,
so as to avoid puckering. When this has been neatly done, the line upon
the face becomes quite invisible after a few months.

In none of the cases, so far, has it been necessary to make a sulcus
above. The same operation could, however, be performed on the upper
lid, provided that, after dissecting up both the borders of the skin flap,
the tendon of the levator were secured with one or two sutures before
dividing it. After the skin flap is in its new position, the cut end of the
levator could be attached to the tarsus. In closing the skin wound, the
ends of these deep sutures should be allowed to project outwards, so
that they may be pulled out when they ultimately become loose. If it
were possible to obtain thoroughly aseptic catgut, the ends of the sutures
might be cut short and buried.

In addition to providing a sulcus, the operation adds half the width
of the flap — viz. 4 mm. to the vertical diameter of the socket.

Transplantation of skin flaps without pedicle. — If there be much
cicatricial contraction, the above operation is not sufficient, and it is
better to transplant skin flaps (dermal or epidermal) from the arm to
the spaces made by freeing the lids. The dissection of the lids should
be deep, and all fibrous bands should be thoroughly divided. Either of
two plans may be adopted. In the first, the conjunctiva is dissected
from the lid margin, and the island of mucous membrane thus formed
furnishes the covering for the central, or apical portion of the new
socket, while the lids and artificially made fornices are clothed with
the flaps from the arm. Or, secondly, the conjunctiva may be divided
horizontally in the centre, and dissected up, except where it covers the
tarsus, and the skin flaps may be used to cover the back of the orbit,
and posterior surfaces of the newly made fornices.

The great difficulty in all these operations consists in keeping the flaps
in close apposition with the soft and yielding tissues of the orbit, otherwise
the flaps shrink, and therefore it is necessary to support and retain them

CHAP. XX.]

THE ORBIT.

617

in position, with some solid material, such as gntta-percha or lead, which
can be cut and mouldod to fit the orbital cavity and fornices. The flaps
may, if necessary, be wrapped round the artificial support, raw surface
outwards, and fastened to it with sutures. After the insertion of the flap
and shell, the edges of the lids are temporarily sewn together, and opened
again in about a week.

Griinert adopts the first method, and then divides the outer canthus
and frees both lids, so that they can be fully everted. The lids are then
well everted, and sutured respectively to the brow and cheek. The skin
flaps are thus easily applied, and good contact can be ensured by pressure
of a bandage. After a couple of weeks the lids can be replaced, and the
outer commissure re-united.

Weeks' operation is a good one. The object of it is to obtain a fixed
attachment for the flap by suturing it to the periosteal tissue of the
margin of the orbit and so prevent shrinking. The external canthus is
divided, an incision is next made
parallel to the edge of the lid, on
the conjunctival surface 3 mm. from
the lid margin, the eyelid is then dis-
sected from the orbital tissues so that
the anterior layer contains only skin,
orbicularis, and tarsus. A groove is
cut reaching down to the orbital mar-
gin and extending from the inner
canthus to the outer commissure. An
oval skin-flap is taken from the inner
surface of the arm, one-third larger
than the raw surfaces to be covered,
and is freed from fat and subcutaneous
tissue. The flap having been folded
with the epithelial surfaces in appo-
sition, three double sutures are passed
through the bottom of the fold. The
flap is wrapped in a piece of sterile
moistened gauze and laid on the
patient's forehead. The cul-de-sac is
examined and cleared of any loose

tags. The double sutures in the flap are now passed through the perios-
teal tissue at the bottom of the groove or cul-de-sac, and are tied on the
cheek over small rolls of gauze (Fig. 260). A suitably-fashioned rubber plate
is inserted into the cul-de-sac. The anterior and posterior margins of the
flap are sutured to the lid margin and to the orbital tissues respectively.

A sterilised dressing and bandage are applied and not removed for
four days unless unfavourable symptoms arise. Tlie plate should remain
in for ten days or a fortnight, and then should be replaced by an
artificial eye. The periosteal sutures should not be disturbed until they
become somewhat loosened — usually in about six to ten days. The
artificial eye must be kept in situ until the shrinkage has ceased, and
must only be removed for cleaning every four to seven days.

Fig, 260. — Weeks' operation,
showing flap in position. 1,
orbital tissue ; 2. flap ; 3. lid ;
4, periosteal tissue ; 5. sutures ;
6. bone of orbit.

618 / DISEASES OF THE EYE. [chap. xx.

Weeks uses, for the plate, dentist's base-plate gutta-percha, which
can be softened by dipping in hot water, and can then be cut to any size
with scissors, while the edges can be made perfectly smooth with a hot
strabismus hook smeared with vaseline, to prevent sticking. Before
insertion the plate should be sterilised by washing and treating with
alcohol and bichloride solution, and lubricated with bichloride vaseline
1-5,000. It should fit snugly without undue pressure.

Temporary Resection of the Outer Wall of the Orbit (Krbn-
lein's Operation) . — This operation was devised by the late Professor
Kronlein, of Ziirich. It is well suited for the removal of tumours of
the optic nerve, and other new growths and cysts in the posterior
part of the orbit, as well as foreign bodies, without sacrificing the
eye-ball, or perhaps even the sight. It may also be employed to
reach purulent foci in the orbit, and has been used to remove some
of the retrobulbar fat in cases of exophthalmic goitre.

The eyebrow and the scalp in the temporal region are shaved,
and the skin of the whole region of the operation is rendered aseptic.

The First Stage of the operation consists in making a curved
incision on the temple through the skin and soft parts. This incision
commences on the temporal ridge, at a point w^here the latter would
be intersected by a horizontal line running 1 cm. above the supra-
orbital margin. The middle point, or apex, of the incision lies in
the centre of a horizontal line, which unites the external canthus with
the outer orbital margin. The end of the incision lies on the zygoma,
in the centre of a horizontal line uniting the external canthus with
the tragus. The length of the incision in adults is 6 to 7 cm., and
the direct distance between its two ends is about 5 cm. Smaller
incisions are inconvenient. In that portion of the incision which
runs along the margin of the orbit it goes to the bone, through the
periosteum.

The Second Stage consists in raising the periosteum from the
inner surface of the outer wall of the orbit with a slightly curved and
somewhat pointed elevator, which is introduced at the exposed
outer orbital margin. The periosteum is separated upwards as far
as 1 cm. above the fronto-malar suture, downwards as far as the
spheno-maxillary fissure, and posteriorly until well behind the
spheno-zygomatic suture. This proceeding is not difficult, as the
periosteum is closely adherent along the orbital margin only, and
at the sutures. The point of the elevator is now passed directly

CHAP. XX.] THE ORBIT. 619

downwards, and carefully introduced into the spheno-maxillary
fissure a few millimetres behind the spheno-zygomatic suture. The
handle of the instrument is then turned over "gently towards the
nose, thus pressing the periosteum and all the contents of the orbit
somewhat inwards, and exposing the bared inner surface of the outer
orbital wall. The object of passing the point of the elevator into
the spheno-maxillary fissure — where it remains during the next stage
of the operation — is to fix the point towards which the osseous in-
cisions are to be made to converge. Some surgeons prefer to omit
this act, and the proximity of the infra-orbital nerve, and of the
infra-orbital vessels, must be borne in mind.

The Third Stage includes the resection of the bony wall by three
incisions, two horizontal and one oblique. The upper horizontal
bony incision is made with a thin, sharp chisel, which should divide
the external angular process of the frontal bone close to its base.
The soft parts having been previously drawn aside, the periosteum
over the seat of the proposed bony incision is divided, and the
orbital periosteum and the lacrimal gland are drawn aside.

The oblique bony incision passes from the deepest part of the
previous incision downwards and backwards behind the spheno-
maxillary suture, through the greater wing of the sphenoid bone, to
a point about 1 cm. behind the anterior end of the spheno-maxillary
fissure, where the point of the elevator has been kept all through.

The lower horizontal bony incision divides the frontal process
of the malar bone close to its base, the soft parts having been
drawn aside, and the periosteum divided. The incision ends at
the anterior extremity of the spheno-maxillary fissure.

In making the bony incisions there is the danger of splintering to
be contended with, and in the oblique incision there is some danger
of luxating the spheno-maxillary suture. The chisel must be very
sharp and thin, and it is well to apply its corner rather than its full
edge to the bone, while only light taps with the mallet are used. It
is important to make the bony incisions in the above order ; or, at
any rate, the oblique incision should not be the last to be made, for,
if it be, the thin outer wall of the orbit is liable to become severely
splintered during the chiselling of the second bony process.

The lower bony incision can also be made (Magitot and Landrieu)
with a Gigli saw passed with a cannula from the temporal fossa
through the spheno-maxillary fissure, and the upper one may be

620 DISEASES OF THE EYE. [chap. xx.

facilitated by first grooving the bone witb a small saw, before using
the chisel.

The Fourth Stage is the turning backwards of the flap of bone and
soft parts, and the exposure of the interior of the orbit. After the
flap has been turned well back, the separated periosteum is divided
with blunt-pointed scissors, from before backwards. It is some-
times necessary, in order to reach the focus of disease, to divide the
tendon of the external rectus near its sclerotic insertion, and possibly
other orbital muscles must be severed ; but this should be avoided,
if possible.

"When all manipulations required in the orbit have been com-
pleted, any muscles which may have been divided are sutured to
their insertions, the periosteum is replaced in its normal position,
the flap of bone and soft parts turned forwards into its place, and
secured there by a few catgut sutures through the periosteum. A
drain is then placed in the lower part of the wound, and the rest of
the wound is accurately closed with fine silk sutures, and an aseptic
dressing and bandage applied. The catgut sutures through the
periosteum, and the drain, are regarded by several operators as un-
necessary.

We have performed the operation for tumours of the optic nerve
(Fig. 257), and other tumours of the orbit, for a mucocele of the
frontal sinus which extended out under the roof of the orbit, and for
diagnostic purposes in a case of pulsating exophthalmos, and have
found it very satisfactory. The resulting scar is not disfiguring
(Fig. 257).

Exophthalmic Goitre (Graves' Disease, Basedow's Disease).

Symptoms. — The three cardinal symptoms of this disease are : in-
creased rapidity of the heart's action, which may reach two hundred
beats per minute ; tumefaction of the thyroid gland ; and exoph-
thalmos, which is nearly always bilateral. Of these the cardiac
symptom is the most constant, and usually the first to appear ;
either, or both of the others, may be wanting. There is often also
great emaciation (Fig. 261), with outbursts of sweating and diarrhoea.
A venous murmur may be heard in the neck, and a thrill can often
be felt over the enlarged thyroid. In females there is very commonly
irregularity or suppression of menstruation.

The disease, which is much commoner in women than in men,
has been observed at all ages, but is most common in early adult life.

CHAt». XX.]

THE) ORBIT.

G2l

Von Grsefe's Sign is a very early, tolerably constant, and almost
pathognomonic one : it consists in an impairment of the consensual
movement of the upper lid in association with the eyeball. When,
in the normal condition, the globe is rolled downwards, the upper
eyelid falls, and thus its margin is kept throughout in a constant
relation to the upper margin of the cornea. In Graves' Disease the
descent of the upper lid does not take
place, or does so imperfectly ; and,
consequently, when the patient looks
down, a zone of sclerotic becomes
visible between the margin of the lid
and the cornea. This symptom is
often present prior to any exophthal-
mos, and hence its great diagnostic
value. It may also continue after
the latter disappears — although it is
perhaps more common for it to dis-
appear before the proptosis — and it is
not seen, or but very rarely so, in
protrusion of the globe from other
causes. But the sign is not so

absolutely pathognomonic as it was held to be by von Graefe ; for
it may be absent in Graves' Disease, although very rarely so, in
the early stages, and it is sometimes present in other diseased states,
and even in health.

Stellwag's Sign, namely, incompleteness and diminished frequency
of the act of involuntary nictitation, is also very constant. This act
occurs sometimes only once in a minute : or several rapid nictita-
tions take place, and then a lengthened pause. The nictitation each
time is incomplete, the margins of the lid not being brought together.
The result may be that the lower third of the cornea becomes covered
with pannus vessels, owing to the constant exposure ; for even
during sleep the eyelids remain partially open.

Dalrymple's Sign consists in an abnormal widening of the palpe-
bral aperture, due to retraction of the upper eyelid. It is this gaping
of the eyelids, with the resulting exposure of the sclerotic above the
cornea, which gives the characteristic staring aspect to the patient.

1 We are indebted to Dr. Martin Dempsey for the photograph of this
patient.

Fig. 261. — Exophthalmic
goitre, accompanied with great
emaciation, in a young lad.^

622 Diseases of the eye. [chap. ^k.

The sign is often erroneously attributed to Stellwag, or is included
in his sign.i

Insufficiency of convergence has been observed by Moebius and
is called Moebius' Sign, but it is not always present and is, we think,
merely indicative of general nervous debility, and not of import-
ance as a sign of Graves' Disease.

Probably the first three ' signs ' are due to the one cause —
namely, loss of power in the orbicularis, rather than over-action of
the levator.

Spontaneous pulsation in the retinal arteries is said to occur, but
it is exceptional. The vision — unless when corneal complications
supervene — and the condition of the pupil are unaffected by the
disease. The pupils and field of vision are also normal. In some
cases there is an increased flow of tears, but most of the patients
complain of a dryness of the eyeballs. The sensibility of the cornea
is diminished. Ulcers of the cornea are not common, but are said
(von Graefe) to be more frequent in men than in women. The ex-
posure of the eye and dryness of the cornea are the chief causes of
ulceration, when it occurs ; we have seen a case in which both eyes
were lost from suppuration of the cornea from exposure.

The patients are often hysterical ; and even marked psychical
disturbances have been noted, such as a peculiar and unnatural
gaiety, rapidity of speech, and great irritability ; or, on the other
hand, extreme depression, and even attempts at suicide have been
observed. Also loss of memory and inability to make a mental
effort. The motions of the eyeball have in some cases been defective
— a fact for which the exophthalmos does not account. Well-
marked muscular tremors, affecting also the orbicularis oculi, are
frequently present, and Trousseau's Cerebral Macula is often seen.

The Progress of the Disease is, as a rule, very chronic, extending
over months or years, but liable to fluctuations in the intensity of
its symptoms. A few cases have been recorded in which it became
fully developed in the course of some hours or days. After a length-

1 Other conditions which produce widening of the palpebral aperture
or ' Staring Eye,' are: — (1) Orbital Tumour (mechanically). (2) Stimu-
lation of the Cervical Sympathetic. (3) Cocaine (in slight degree, prob-
ably by reason of 2). (4) Women after child-birth (hysteria). (5) In
tetanus (spasm of occipito-frontalis). (6) In complete amaurosis, and
(7) it is seen rarely in some healthy individuals on fixation and convergence
for a near object.

ChAi^. XX.] THE ORBlf. (l2:i

ened period, and iiuiiiy lluctuutioiis, the symptoms usually slowly
disappear. Occasionally a slight permanent s\vellin«i of the thyroid
may remain, and very often more or less exophthalmos. About
12 per cent, of the cases go from bad to worse, and end fatally from
general exhaustion, organic disease of the heart which may have
come on, cerebral apoplexy, hfiemorrhage from the bowels, or gan-
grene of the extremities.

Causes. — Anaemia and clilorosis are general conditions very
often present, as are, also, irregularities of menstruation ; but it is
probable that the latter should be regarded rather as a concomitant
symptom than as a cause. Severe illnesses are recorded as having
gone before the onset in many cases, and also excessive bodily or
mental efforts. Great sexual excitement has been known to be
followed by Graves' Disease, and depressing psychical causes are
not unfrequent forerunners of it. In many instances, how^ever, the
patients have been perfectly healthy, and no cause could be assigned.
The Enlargement of the Thyroid is due in the first instance to
dilatation of its vessels ; but in a late stage hypertrophy of the
gland tissue may be produced, and increase of its connective tissue,
and even cystic degeneration. The Exophthalmos is due to hyper-
emia of the retro-bulbar orbital tissues, as is demonstrated by a
vascular bruit often present, and the fact that steady pressure on
the globe diminishes the protrusion. Hypertrophy of the orbital
fat may be found ])ost mortem, but it is, doubtless, secondary to the
hyper^emia.

With regard to the nature of the disease, very many theories
have, from time to time, been put forward. It is most probable
that the disease is due to the excessive or altered secretion of the
thyroid gland.

Treatment. — A principal part of this consists in the careful
regulation of the patient's general health and functions. Freedom
from mental anxiety and excitement, regular hours, much resting
with moderate exercise on the flat, and change of air are the most
important items.

The fluctuations, which occur in the intensity of the symptoms,
render it difficult to arrive at definite conclusions w^ith regard to the
efficacy of remedies, a vast number of which have been tried and
lauded from time to time. In mild forms of the affection, and
especially if the anaemia be well marked, iron internally is beneficial,

624 DISEASES OF THE EYE. [chA?. 55:x.

but in severe cases it has the opposite effect. Quinine in moderate
closes has been employed with benefit in some cases. Trousseau
recommended digitalis in large doses, but its effect must be watched.
The beneficial action of iodide of potassium in ordinary goitre has
suggested its use in this disease ; but under its influence the symp-
toms are sometimes aggravated, and it is doubtful whether they
are ever relieved by it. Aconite has been praised highly, and so has
belladonna. Ergotin internally has been tried, and with advantage
in some instances. Sattler warmly recommends a well-regulated
hydropathic treatment, when the patient is not too excitable.
Paroxysms of cardiac palpitations, etc., are best combated by ice
applied to the head, heart, and goitre. The sympathetic theory
has induced the trial of a galvanic treatment of the cervical sym-
pathetic. Thyroid extract has proved beneficial in some cases, also
antithyroidin and the milk of thyroidectomised goats.

Gauthier recommends antipyrin before everything else. Ex-
tract of the thymus gland has been occasionally employed, and
with encouraging results.

Partial extirpation of the thyroid has been performed in recent
years with success in some cases.

The great number of remedies which have been proposed for the
disease demonstrates its intractable nature. Yet a considerable
proportion of the cases do undergo cure, in so far as quieting of the
heart's action, and reduction, or, possibly sometimes, complete
disappearance, of the goitre and exophthalmos, are concerned. It
is common, however, even in the best recoveries, to see some ex-
ophthalmos remain permanently.

In cases where the exophthalmos is so great that the cornea is
exposed even during sleep, it is desirable to perform tarsoraphy (p.
561) ; and the same operation is indicated when, the disease having
subsided, the exophthalmos still remains to a degree which gives
the patient a disagreeable expression.

APPENDIX.

REGULATIONS AS TO DEFECTS OF VISION WHICH DISQUALIFY
CANDIDATES FOR ADMISSION INTO THE CIVIL, NAVAL,
AND xMILITARY GOVERNMENT SERVICES, THE ROYAL
IRISH CONSTABULARY, AND THE MERCANTILE MARINE.

Candidates for Commissions in the Army (including the Royal Army
Medical Corps) and Special Reserve. — Squint, or any morbid condition
of the eyes or of the lids of either eye liable to the risk of aggravation or
recurrence, will cause the rejection of the candidate.

The examination for determining the acuteness of vision includes two
tests : one for distant, the other for near vision. The Army Test Types
will be used for the test for distant vision, without glasses except where
otherwise stated below, at a distance of 20 feet : and Snellen's Optotypi
for the test for near vision, without glasses, at any distance selected by the
candidate. Each eye will be examined separately, and the lids must be
kept wide open during the test. The candidate must be able to read the
tests without hesitation in ordinary daylight.

A candidate possessing acuteness of vision, according to one of the
standards herein laid down, will not be rejected on account of an error
of refraction, provided that the error of refraction, in the following cases,
does not exceed the limits mentioned, viz. : (a) in the case of myopia, that
the error of refraction does not exceed 2*5 D ; (6) that any correction for
astigmatism does not exceed 2'5 D ; and, in the case of myopic astigmatism,
that the total error of refraction does not exceed 2*5 D.

Subject to the foregoing conditions, the standards of the minimum
acuteness of vision with which a candidate will be accepted are as follows : —

Standard I.

Right eye. Left eye.

Distant vision.— V = 6/6. V = 6/6.

Near vision. — Reads 0, 6. Reads 0, 6.

40 625

626

APPENDIX.

Standard II.

Better eye.
Distant vision. — V = 6/6.

Near vision. — Reads 0, 6.

Worse eye.

V, without glasses, = not below
6/60 ; and, after correction with
glasses, = not below 6/24.

Standard III.

Better eye.

Distant vision. — V, without glasses
= not below 6/24 ; and, after
correction with glasses, = not
below 6/6.

Near vision. — Reads 0, 8.

Worse eye.

V, without glasses, = not below
6/24 ; and, after correction with
glasses, = not below 6/12.

In Standard III., the standard for the test for distant vision, without
glasses, for officers of the Special Reserve, will be not below 6/36.

Inability to distinguish the principal colours will not be regarded as a
cause for rejection, but the fact will be noted in the report and the candi-
date will be informed.

The degree of acuteness of vision of all candidates for commissions
(including preliminary examinations) will be entered in their reports in
the following manner : —

Q i^ . 4. /Right eye V = Reads

Sufficient T 7^ T/ r» j

(Left eye V = Reads

^ , . fRight eye V = Reads

Defective ( Left eye V= Reads

No relaxation of the standard of vision will ever be allowed.
Recruits for all Arms of theMilitary Service.— In examininga recruit's
vision he will be placed with his back to the light, and his visual acuteness
will be tested by means of test types placed, in ordinary daylight, at a
distance of six metres (20 English feet) from the recruit.
Each eye will be tested separately : —

(a) If a recruit can read D = 24 at 20 feet, or better, with each eye
without glasses, he will be considered " FIT."

(6) If he can read D = 6 at the same distance with one eye, without
glasses, and not less than D = 36 with the other eye, without glasses^
he will be considered "FIT."

APPENDIX. 627

The foregoing is the standard test of vision for all arms of the service,
with the exception of tlie Cori)s of Army Schoolmasters, for which a candi-
date will be accepted if tlie examining medical officer is satisfied that his
vision, with or without glasses, is good.

The visual acuity of each eye in the case of approved recruits will be
entered on the medical history sheet.

The Royal Navy.— Candidates for Naval Cadetships must possess full
normal vision (Emmetropia, and V = 6/6) as determined by Snellen's
tests, each eye being separately examined.

For candidates for other branches of the Royal Navy, full normal
vision is not required, but any defect of vision must be due to errors of
refraction which can be corrected to normal by glasses, and vision without
glasses must in any case be not less than 6/60 with each eye, and the
candidate must also be able to read D = 0, 6 of Snellen's test types. A
candidate is disqualified by any imjoerfection of his colour sense.

Strabismus, any defective action of the orbital muscles, any derange-
ment of the lacrimal apparatus, or any chronic disease of the eyes or eye-
lids disqualifies.

For candidates for the seaman class (including boys and youths),
marines (excluding marine bandsmen), armourer ratings, engine-room
artificers, electricians and boy artificers, full normal vision is required.

For candidates for other artisan ratings and for stokers, the vision
must be 6/8.

For all other ratings, including writers, ship's stewards' assistants,
ship's cooks, sick berth staff, boy writers, ship's stewards' boys, and
officers' stewards and cooks, the vision must not be less than 6/12.

For all ratings except writers, ship's cook ratings, and officers' servants,
the colour sense must be normal.

Defects of vision must only be due to errors of refraction, and must
be capable of correction to 6/6 Snellen by means of glasses, and the candi-
date must be able to read D = 0, 6 without the aid of glasses.

Marine bandsmen, sick berth staff, Avriters, ship's steward ratings,
ship's cook ratings, and officers' servants are allowed to wear glasses.

Home Civil Service. — Any serious defect of vision disquahfies. A
moderate degree of ordinary short sight corrected by glasses would not
as a rule be regarded as a disqualification ; but candidates for the Cus-
toms Outdoor Service are liable to disqualification for any defect of vision.
Candidates for some other appointments of a special character would be
rejected for colour-blindness, but for ordinary home appointments it is
not by itself a disqualification.

No precise standard of eyesight is at present laid down for candidates
for appointment as assistants of Customs and Excise. Under the existing
rules, it is probable that a moderate degree of short sight, properly
corrected by glasses, would not of itself be held to disqualify, but axiy

628 APPENDIX.

serious defect of vision would be a disqualification. The Regulations,
however, are liable to alteration, and the Civil Service Commissioners
cannot say what rule in regard to eyesight may be in force for subsequent
competitions.

The Commissioners cannot undertake to give prospective decisions
in the case of intending candidates, or to define more closely the requisite
standard.

For the situations of Customs Preventive Man and Parkkeeper in the
Royal Parks, candidates must have vision acute enough to perform their
duties without the use of glasses ; a practical test is made, if necessary,
by officers of the departments concerned.

The Indian Civil Service. — 1. A candidate may be admitted into the
Civil Services of the Government of India if ametropic in one or both eyes,
provided that, with correcting lenses, the acuteness of vision be not less
than 6/9 in one eye and 6/6 in the other ; there being no morbid changes
in the fundus of either eye.

2. Cases of myopia, however, with a posterior staphyloma, may be
admitted into the service, provided the ametropia in either eye does not
exceed 2*5 D, and no active morbid changes of chorioid or retina be present.

3. A candidate who has a defect of vision arising from nebula of the
cornea is disqualified if the sight of either eye be less than 6/12 ; and in
such a case the acuteness of vision in the better eye must equal 6/6, with
or without glasses.

4. Squint or any morbid condition, subject to the risk of aggravation
or recurrence, in either eye, may cause the rejection of a candidate.
The existence of imperfection of colour sense will be noted on the
candidate's papers.

India. The Departments of Forest, Survey, Telegraph, Factories,
and for various Artificers.^ — 1. If myopia in one or both eyes exists, a
candidate may be passed, provided the ametropia does not exceed 2*5 D,
and if with correcting glasses, not exceeding 2 "5 D, the acuteness of vision
in one eye equals 6/9 and in the other 6/6, there being normal range of
accommodation with the glasses.

2. Myopic astigmatism does not disqualify a candidate for service ;
provided the lens or the combined spherical and cylindrical lenses re-
quired to correct the error of refraction do not exceed 2*5 D ; the acute-
ness of vision in one eye, when corrected, being equal to 6/6, and in the
other eye 6/9, together with the normal range of accommodation with
the correcting glasses, there being no evidence of progressive disease in
the chorioid or retina.

3. A candidate having total hypermetropia not exceeding 4 D is not

1 Artificers engaged in map and plan drawing may be considered
separately, and this standard relaxed if it appears to be desirable.

-4 PPENDIX. 629

disqiialilicd, provided the siglit in one eye (when under the inlluencc of
atropine) equals 0/9, and in the other eye equals 6/6, with + 4 D or any
lower power.

4. Hypermetropic astigmatism does not disqualify a candidate for
the service, provided the lens or comlMued lenses re<iuircd to correct the
error of refraction do not exceed 4 J), and that the sight of one eye equals
6/9 and of the other 6/6, with or without such lens or lenses.

5. A candidate having a defect of vision arising from nebula of the
cornea is disqualified if the sight of one eye be less than 6/12. In such a
case the better eye must be emmetropic. Defects of vision arising from
pathological or other changes in the deeper structures of either eye, which
are not referred to in the above rules, may exclude a candidate for ad-
mission into the service.

6. Squint or any morbid condition, subject to the risk of aggravation
or recurrence, in either eye, may cause the rejection of a candidate. The
existence of imperfection of colour sense will be noted on the candidate's
pa})ers.

India. Public Works Department and Superior Establishments,
Railway Department. — 1. If myopia in one or both eyes exists, a candi-
date may be passed, provided the ametropia does not exceed 3*5 D, and
if, with correcting glasses not exceeding 3'5 D, the acuteness of vision in
one eye equals 6/9 and in the other 0/6, there being normal range of
accommodation with the glasses.

2. Myopic astigmatism does not disqualify a candidate, provided the
lens or the combined spherical and cylindrical lenses required to correct
the error of refraction do not exceed 3"o D ; the acuteness of vision in
one eye, when corrected, being equal to 6/9, and in the other 6/6,
together with normal range of accommodation with the correcting glasses,
there being no evidence of progressive disease in the chorioid or retina.

3. A candidate having total liypermetropia not exceeding 4 D is not
disqualified, provided the sight in one eye (when under the influence of
atropine) equals 6/9, and in the other eye equals 6/6, with + 4 D glasses,
or any lower power.

4. Hypermetropic astigmatism does not disqualify, provided the lens
or combined lenses required to cover the error of refraction do ncjt exceed
4 D, and that the sight of one eve equals 6/9, and the other 6/(>, \\ith or
without such lens or lenses.

5. A candidate having a defect of vision arising from nebula of the
cornea is disqualified if the sight of that eje be less than 6/12. In such a
case the better eye must be emmetropic. Defects of vision arising from
pathological or other changes in the deeper structure of either eye, which
are not referred to in these rules, may exclude a candidate.

0. Squint or any morbid condition, subject to the risk of aggravation
o«- recurrence, in either eye, may cause the rejection of a candidate. Any

C30 APPENDIX.

imperfection of the colour sense is a disqualification for appointment to
the Engineering Branch of the Railway Department, or as Assistant
Superintendent in the Traffic Department. In all other cases a note as
to any imperfection of colour sense will be made on the candidate's papers.
The Indian Medical Service, and the Indian Police Department. —

1. Squint or any morbid condition of the eyes or (i the lids of either eye,
liable to the risk of aggravation or recurrence, will cause the rejection of
the candidate.

2. The examination for determining the acuteness of vision includes
two tests : one for distant, the other for near vision. The Army test types
will be used for the test for distant vision, without glasses, except where
otherwise stated below, at a distance of 20 feet ; and Snellen's Optotypi
for the test for near vision, without glasses, at any distance selected by
the candidate. Each eye will be examined separately and the lids must
be kept wide open during the test. The candidate must be able to read
the tests without hesitation in ordinary daylight.

3. A candidate possessing acuteness of vision, according to one of the
standards herein laid down, will not be rejected on account of an error of
refraction, provided that the error of refraction, in the following cases,
does not exceed the limits mentioned, viz. : — {a) in the case of myopia, that
the error of refraction does not exceed 2*5 D ; (6) that any correction for
astigmatism does not exceed 2*5 D ; and, in the case of myopic astigma-
tism, that the total error of refraction does not exceed 2*5 D.

4. Subject to the foregoing conditions, the standards of the minimum
acuteness of vision with which a candidate will be accepted are as follows : —

Standard I.

Bight eye. Left eye.

Distant vision.— V - 6/6. V = 6/6.

Near vision. — Reads 0, 6. Reads 0, 6.

Standard II.
Better eye. Worse eye.

Distant vision. — V = 6/6. V, without glasses, = not below

6/60 ; and after correction with
glasses, = not below 6/24.

Near vision. — Reads 0, 6. Reads 1.

Standard III.
Better eye. Worse eye.

Distant vision. — V, without glasses V, without glasses, = not below
= not below 6/24 ; and after 6/24 ; and, after correction with

correction with glasses, = not be- glasses, = not below 6/12.

low 6/6.

]S^ear vision. — Reads 0, 8. Reads 1.

APPENDIX. 631

The Indian Pilot Service, and Candidates for Appointments as
Guards, Engine-drivers, Signalmen and Pointsmen on Indian Rail-
ways. — 1. A candidate is disqualiiied unless both eyes are emmetropic, his
acuteness of vision and range of accommodation being perfect.

2. A candidate is disqiialihed by any imjierfection of his colour sense.

3. Strabismus, or any defective action of the exterior muscles of the
eyeball, disqualifies a candidate for these branches of service.

The Indian Marine Service, including Engineers and Firemen.—] .
A candidate is disqualified if he have an error of refraction in one or both
eyes which is not neutralised by a concave or by a convex 1 D lens, or some
lower power.

2. A candidate is disqualified by any imperfection of his colour
sense.

3. Strabismus, or any defective action of the exterior muscles of the
eyeball, disqualifies a candidate for this branch of service.

Royal Irish Constabulary. — A candidate for Cadetship in the Royal
Irish Constabulary must be able to read with each eye separately, and
without glasses, Snellen's Metrical Test Types (Edition 1898) numbered
D = 10, at 20 English feet, and those numbered D = 0, 8 at any distance
selected by the candidate himself. Squint, inability to distinguish the
principal colours, or any morbid condition liable to the risk of aggravation
or recurrence in either eye, will involve the rejection of the candidate.

The British Mercantile Marine. Form Vision Test. — The test is the
letter test on Snellen's principle, for all candidates, and they are not
allowed to wear spectacles or glasses of any kind.

On and after January 1, 1914, a higher standard of Form Vision will
be required of candidates, but the colour vision and colour ignorance
tests will be unaltered. The new Form Vision Test will be as follows : —

If a candidate can read correctly at a distance of 16 feet nine of
the twelve letters in the sixth line from the top and eight of the fifteen
letters in the seventh line with one eye, and the whole of the eight letters
in the fifth line with the other eye, he may be considered to have passed
the test. If he cannot do so, his case is submitted to the Principal
Examiner of Masters and Mates.

Candidates may use both eyes or either eye when being tested for this
standard.

Candidates who before January 1, 1914, shall have obtained any
certificate of competency as Master or Mate (foreign-going or home
trade), shall have the option of undergoing the present tests, and shall
not, in order to obtain certificates of higher grades, be required to pass
the more severe test.

Colour Vision Test. — The colour vision of candidates is tested by
Holmgren's Method.

Colour Ignorance Test. — The object of this test is to ascertain whether

632 APPENDIX.

the candidate knows the names of the three colours — red, green, and
white — and the test is confined to naming those colours.

The Board of Trade examinations for Form Vision, Colour Vision,
and Colour Ignorance are open to all jDersons intending to serve in the
Mercantile Marine, and all such persons are recommended to ascertain,
by means of these examinations, whether their vision is such as to qualify
them for service in that profession before entering upon it.

^scy

+ 5vi»

^-o

o06"

INDEX.

Aberration, chromatic, 407 ;
spherical, 407.

Absolute alcohol, treatment for
ulcers, 134.

Absorption ulcer, 106.

Accommodation, 5 ; mechanism of,
5 ; range of, 6, 8 ; and abnormal
refraction, 414 ; anomalies of,
460 ; amplitude of, 6 ; paralysis,
of, 463 ; spasm of, 465 ; syn-
kinesis, 230.

Acromegaly, 365.

Acute ascending paralysis, 382.

Acuteness of vision, 14.

Advancement operation in strabis-
mus, 523.

Albinismus, 224.

Alexia, cortical, 370.

Amaurosis, temporary, 104 ; fugax,
327 ; quinine, 330 ; from filix
mas, 331 ; spinal, 354 ; pre-
tended, 393 ; Grsefe's test in,
393 ; Harlan's test in, 394 ;
crossed diplopia test in, 393 ;
Snellin's coloured types, 394.

Amaurotic family idiocy, 375.

Amblyopia, glycosuric, 358 ; cen-
tral toxic, 358 ; congenital, 391 ;
ex anopsia, 512 ; during preg-
nancy, 391 ; reflex, 391 ; urae-
mic, 392 ; toxic, 349,353 ; nervous,
383 ; nervous in neurasthenia,
386 ; nervous in hysteria, 388 ;
nervous in traiunatic neurosis,
389.

Ametropia, 414 ; quantitative de-
termination of, 449.

Amnesic colour-blindness, 371.

Anaphoria, 527.

Anel's syringe, 587.

Angiomata, 007.

Aniridia, 223 ; traumatic. 213.

Anisocoria, 374.

Anisometropia, 447.

Ankyloblepharon, 577.

Anophthalmos, cysts with. 000.

03:

Anterior chamber, cysts of, 21 G ;
haemorrhage into, 284; late ap-
pearance of, in cat. operation. 280.

Anterior synechia, 04.

Aphakia, 295.

Aphasia, 307 ; visual, 370.

Arcus ssnilus, 162.

Argyll Robertson pupil. 381.

Argyrol, 54.

Argyrosis, 54.

Arsenic, poisoning with, 350.

Artificial eyes, 200.

Artificial leech, 489.

Aspherical lenses, 297.

Asthenopia, accommodative, 434 ;
muscular, 473, 527 ; nervous, 383

Astigmatism, 430 ; regular, 430 ;
hypermetropic, 437 ; mixed, 437;
myopic, 437 ; estimation of the
degree of, 441; lental, 445;
irregular. 440.

Astigmometer, 443.

Ataxy, hereditary, 382.

Atrophy of optic nerve, simple,
353 ; consecutive. 353 ; primary
of, 354 ; general chorioidal, 424]^

Atropine, action of on pupil, 233 ;
poisoning, 181 ; eczema. 181 ;
dangers of, 182.

Axial neuritis, 349.

Axis-finder (Maddox's), 411.

Bacteriology of conjunctivitis, 48.

Basedow's disease, 020.

Bergeon's treatment for rodent
ulcer, 552.

Binocular vision, 473.

Bitot's spots, 97.

Bjerrum's test for central scotoma.
20.

Blennorrhoea neonatorum, 58.

Blennorrhoea of the lacrimal sac,
586.

Blepharitis, marginal, 543 ; ul-
cerosa, 543 ; squamosa, 543 ;
ectropion, 574.

633

INDEX.

Blepharophimosis, 564 ; (Cantho-

plastic operation), 564.
Blepharoptosis, 554.
Blepharospasm, 103, 554.
Blind spot of Marriotte, 19.
Blue blindness, 337.
Bowels, haemorrhages from, c57.
British mercantile marine, 631.
Buphthalmos, 260.

Canaliculus, obstrviction of, 582 ;
streptothrix in, 582.

Canthoplastic operation, 566.

Capsule of Tenon, inflammation of
the, 598.

Capsulotomy, 291.

Carbolic acid for corneal ulcers, 134

Carbon dioxide snow, 81, 547.

Carcinoma of chorioid, 220; of
ciliary body and iris, 217.

Caruncle lacrimale, 42 ; tumours of,
101.

Cataract, anterior polar or pyra-
midal, 271 ; black, 269 ; cap-
sular, 273 ; central capsular, or
pyramidal, 65 ; central, 269 ; com-
plete, 261 ; complete congenital,
268 ; complete of young people,

268 ; diabetic, 268 ; fusiform or
spindle shaped, 271; glass-blower's,

269 ; Morgagnian, 262 ; partial,
269 ; posterior polar, 271. 272 ;
punctate, 271 ; secondary, or com-
plicated, 272, 291 ; senile, 261 ;
total secondary, 272 ; trau-
matic, 273 ; zonular or lamellar,
269.

Cataract, artificial ripening of,
268 ; combined operation for,
278 ; extraction of capsule (in
cat. operation), 290 ; extraction
without iridectomy, 288 ; linear
extraction of, 277 ; operations
for, 275 ; simple operation for,
288 ; spontaneous cure of, 264 ;
pathogenesis of senile, 265.

Cataract extraction, accidents during
operation. 284 ; irregularities in
healing after, 285.

Cataracta accreta, 272 ; mem-
branacea, 264 ; nigra, 264.

Cautery, actual, 117.

Cavernous sinus, thrombosis of the,
502, 598.

Cellulitis of orbit, 597.

Central chorioiditis, 191 ; senile,
guttate chorioiditis, 191 ; toxic
amblyopia, 358. ^^- ._ _

Cerebral synkinesis, 231.

Cerebro-spinal meningitis, 344.

Chalazion, 546.

Chemosis, 45, 91.

Cherry-red spot in obstruction of
retinal vessels, 325.

Chlorosis, 345.

Choked disc, 342.

Chorea, 378.

Chorio -retinitis, 314.

Chorioid, central senile areolar
atrophy of, 222 ; coloboma of,
224; detachment of, 221, 288;
extravasation of blood in the,
215 ; gyrate atrophy of the
retina and, 330 ; injuries of,

214 ; malformations of, 224 ;
new growths of, 217 ; posterior
staphyloma of, 221 ; rupture of,

215 ; sarcoma of, 220.
Chorioidal exudation near macula

lutea, 423 ; degeneration near
macula lutea, 423.

Chorioiditis, central, 191 ; central
senile guttate, 191 ; disseminated,
189 ; purulent, 192.

Chromidrosis, palpebral, 548.

Chronic nuclear paralysis, 494.

Chronic polio-encephalitis of Wer-
nicke, 494.

Cilia, excision of, 566.

Ciliary body, injuries of, 214 ; new
growths of, 217; congestion, 45.

Civil service, vision required for the.
627 ; Indian, 628.

Coloboma of chorioid, 224 ; con-
genital, of up. lid, 579 ; of iris,
223 ; of lens, 225 ; of sclerotic,
172.

Colour - blindness, 358 ; amnesic,
371.

Colour fields, inversion of the, 585 ;
sense, the, 10, 11 ; tests, 13.

Columbia spirit or wood alcohol,
352.

Commotio retinae, 340.

Congestion, ciliary, 45 ; conjunc-
tival, 45 ; papilla, 342.

Conjunctiva, diseases of, 42 ; ex-
amination of, 42 ; chemosis of,
91 ; and cornea, examination of
in infants and children, 44 ; hy-
peraemia of, 45 ; acute blen-
norrhof a of, or purulent ophthal-
mia, 58 ; tubercular disease of
the, 84 ; lupus of the, 86 ;
syphilitic disease of the, 87 ; lim-
bus of the, 42 ; ulcers of, 87 ;

INDEX.

637

pempliigus of the. 89 ; emphy-
sema of the. 91 ; injuries of the,
91 ; degenerative diseases of, 93 ;
hyahne. colloid, and amyloid
degeneration of, 97 ; cysts of,
98 ; tumours of, 99 ; xerosis of
the, 130 ; shrinking of the, 615 ;
Weeks' operation for shrinking
of the. 617; epithelioma and
sarcoma of, 100.
Conjunctival flap (Kuhnt's), 121.
Conjunctivitis, 4() ; varieties of, 47 ;
bacteriology of , 48 ; catarrhal, 49 ;
simple acute. 49 ; muco-puru-
lent, 49 ; diplobacillary, or an-
gular, 55 ; chronic simple, or
chronic catarrhal. 56 ; mem-
branous, 66 ; croupous, 66, 67 ;
diphtheric. 68 ; granular, 70 ;
tollicular. 82 ; Farinaud's, 85 ;
vernal, 87 ; petrificans, 90 ; phlyc-
tenular, 102 ; post operative,
286 ; nitrate of silver in, 54 ; an-
gular, 55.
Convergence, 9 ; range and ampli-
tude of, 9 ; insufficiency of, 425,
534.
Corectopia, 223.

Cornea, diseases of, 110 ; clinical
methods of examining, 110 ; in-
flammations of, 112 {sp,e Keratitis);
ulcerative inflammations of, 112
{see also Ulcers) ; deep ulcer of
the, 123 ; fistula of the, 123 ;
infantile ulceration of the, 130 ;
non-ulcerative inflammation of
the, 136 ; abscess of the, 136 ;
ring abscess of the, 137 ; syphi-
litic diseases of the, 137 ; gumma
of the, 141 ; sclerotising opacity
of the, 144 ; transverse calcare-
ous films of the, 145 ; cal-
careous film of the, 145 ; super-
ficial epithelial dystrophy of, 146 ;
ectasies of the, 146 ; staphyloma
of the, 146 ; abscission of, 147 ;
conical, 150 ; atrophic degenera-
tion of the margin of the, 152 ;
tumours of the, 153 ; injuries of
the, 153 ; foreign bodies in the,
153 ; simple traumatic losses of
substance, or abrasions, 155 ;
recurrent abrasion, 156 ; dis-
junction of the, 156 ; recurrent
traumatic keratalgia, 156;h8Dmor-
rhagic discoloration of the, 157 ;
injuries with caustic substances
of the, 157 ; perforating injuries

of the, 158 ; opacities of the, 160 ;
globosa, 260 ; limbus of the, 42.

Corneal microscope, 112.

Corpuscle, or trachoma cells, 71.

Credo's method of prophylaxis in
ophthalmic neonatorum, 60.

Crossed diplopia test, 393.

Crossed hemiplegia, 501.

Crystalline lens, diseases of. 261 ;
dislocation of, 259, 294 ; absence
of (aphakia), 295 ; congenital
defects of, 295 ; coloboma of,
295; opacities of [see Cataract).

Cyclitis, 187 ; acute, 187 ; tuber-
cular, 189; treatment of, 189.

Cyclodialysis for glaucoma (Heine's
operation), 256.

Cyclophoria, 533.

Cycloplegia, 463.

Cysticercus, subretinal, 335 ; sub-
conjunctival, 98 ; in vitreous
humour, 311.

Cystoid cicatrix, 288.

Cysts, of the conjunctiva, simple, 98;
retention, 98 ; implantation, 98 ;
congenital, 98 ; of the iris, 216 ;
of the anterior chamber, 216 ;
Meibomian, 547 ; tarsal, 547 ;
of the lacrimal gland, 594 ; or-
bital, 605 ; dermoid, 605 ; with
anophthalmos, 606 ; parasitic,
606.

Dacryoadenitis, 592.
Dacryocystitis, chronic, 586 ; acute,

591.
Dacryocystorhinostomy, 591.
Dacryolith, 582.
Dacryops, 594.
Dalrymple's sign, 621.
Dermo-lipoma of conjunctiv^a, 99.
Descemet's membrane, 110.
Deviometer (Worth's), 515.
Diabetes, retinal affections in, 318.
Diaphanoscopy, 219.
Diaphragm test (Harman's), 535,
Diffuse sclerosis of brain, 374.
Dioptric system, 3.
Dioptric unit, 409.
Diplopia, 474 ; false image in, 474 ;

homonymous, 474 ; crossed, 475 ;

monocular, 474.
Diploscope, of Remy, 535.
Disc, choked, 342 ; waxy, 354.
Discission, 293.

Disseminated sclerosis, 346, 372.
Distichiasis, 74, 565.
Donders' diagram, 460.

638

INDEX.

Dor's treatment for detached re-
tina, 339.
Dunbar's hay fever serum, 70.
Dyslexia, 370.

Ectopia of lens, 295.

Ectropion, 572 ; of lower lid, 57 ;
blepharitis, 574 ; cicatricial, 574 ;
muscular, 572 ; paralytic, 577 ;
senile, 572 ; of uveal pigment,
224 ; Wolfe's operation for, 576.

Eczema after use of atropine, 181 ;
of eyelids, 541 ; sc[uamosa, 543 ;
pustulosa, 543.

Edridge-Green's theory of colour
sense, 11.

Electric light, blinding of retina by,
333.

Electro-magnets (Snell's), 308 ;
Haab's Giant, 309.

Electrolysis, 547, 566.

Elementary optics, 396.

Elephantiasis lymphangioides, 542 ;
nostras, 542.

Elliot's operation for glaucoma,
254 ; trephine, 254.

Embolism and thrombosis of cen-
tral artery of retina, 325.

Emmetropia, 4.

Emphysema of eyelids, 578.

Endarteritis of retinal vessels, 323.

Endophthalmitis, 210.

Enophthalmos. 602.

Entropion, 568 ; spastic, 568 ; se-
nile, 568 ; Snellen's operation
for, 569 ; Berlin's operation for,
570 ; Hotz's operation for, 570 ;
operation by excision of skin, 570.

Ermcleation or excision of eyeball,
206.

Epicanthus, 505, 555, 578.

Epilation, 566.

Epilepsy, 378.

Epiphora, 580.

Episcleritis, 164 ; hot eye (Hutchin-
son), 164 ; periodic transient
(Fuchs), 164.

Epithelial plaques, 93 ; xerosis, 97.

Epithelioma of conjunctiva, 100 ;
of eyelids, 553.

Erythropsia, 394.

Esophoria, 527.

Ethmoid cells, disease of, 618.

Euphos glass, 334, 413.

Everbusch's operation for ptosis,
555, 557.

Evisceration, 147, 207.

Exophoria, 527.

Exophthalmic goitre, 620.

Exophthalmometers, 596.

Exophthalmos, 343, 596 ; pulsating^
609 ; intermittent, 609.

Exostoses of orbit, 607.

Expulsive haemorrhage in cataract
extraction, 286.

External rectus, paralysis of, 478.

Extorsion (wheel motion), 467.

Eyeball, rupture of, 169.

Eyelids, eczema of, 541 ; oedema
of, 541 ; angio-neurotic oedema
of, 542; solid oedema of, 5; 2;
elephantiasis lymphangioides of,
542 ; elephantiasis nostras, 542 ;
marginal blepharitis of, 543 ;
hordeolum of, 545 ; chalazion,
546 ; milium, 547 ; molluscum
contagiosum, 547 ; telangiectic
tumours or naevi of, 547 ; xan-
thelasma of, 547 ; syphilitic
affections of, 550 ; vaccine vesi-
cles on, 551 ; neuro-fibroma of,.
553 ; lymphoma of, 553 ; epi-
thelioma, sarcoma and lupus of,
553 ; gangrene of, 553 ; ptosis,
554 ; symblepharon, 562 ; ble-
pharophimosis, 564 ; entropion
of, 568 ; ectropion of, 574 ; anky-
loblepharon, 577 ; injuries of,
677 ; emphysema of, 578 ; colo-
boma of, 579.

False image in diplopia, 474.

Far point, 4, 6, 415 ; in hyper-

metropia, 429 ; in myopia, 415.
Fatigue field, 385.
Fergus's operation for ptosis, 555,

559 ; for ectropion, 573.
Fibrolysin, 302.
Fibroma of sclerotic, 168.
Field of vision, 17 ; concentric

contraction of, 389.
Fifth nerve, paralysis of, 505.
Fixation, line of, ^3 ; field of, 471 ;

binocular, 473.
Fluorescine, 111.

Focal or oblique illumination, 110.
Follicular conjunctivitis, 82.
Folliculosis, 82.
Foreign body in eye, 303 ; detection

of, 304.
Form sense, 14.
Fornix, excision of, 79.
Fourth nerve, paralysis of, 503.
Fovea centralis, 40.
Friedrich's disease, 382.
Frohlich's syndrome, 365.

INDEX.

(130

Frontal sinus, the, 612.
Fusion, sense of. 473. 510.

Galvanism in paralyses, 490.

Ganglia, primary ojitic. 'MVl.

General paralysis of the insane. .374

Gerlier's disease, 494.

Gerontoxon. 102.

Gigantism, 305.

Glaucoma, primary, 235 ; ehronic
simple, 235, 238 ; congestive
235 ; chronic non-congestive
238 ; acute, 243 ; acute congestive
243 ; fulminans, 245 ; suba
cute, 246 ; etiology of. 246
pathology of. 246 ; malignant
250 ; non-operative treatment
of, 257 ; secondary, 258, 291, 328
haemorrhagic. 259 ; ElHot's opera-
tion for, 253 ; tension in, 230
operations for, 250.

Glaucomatous, ring, 240 ; eyes,
treatment of painful blind, 258.

Globe, evisceration of, 147.

Glycosuric amblyopia, 358.

Goggles, airtight, 89.

Goitre, exophthalmic, 620.

Gonorrhoeal iritis, keratitis and
scleritis, 05 ; ophthalmia, 58 ;
ophthalmia, metastatic, 65.

Grady's forceps, 78.

Graefe's, Alfred, test for pretended
amaurosis, 393.

Grafting, Wolfe and Lefort's method
of, 577.

Gram's method of staining, 49.

Granular conjunctivitis, 70.

Graves' disease, 620.

Gumma of cornea, 141 ; sclerotic,
167.

Haab's magnet, 309.

Haemophthalmos, 170.

Haemorrhage into anterior chamber,
in cat. operation, 284 ; in eye-
lids, 601 ; from stomach, bowels
or uterus, 357 ; in retina at
yellow spot, 424.

Haemosiderin, 150.

Hallucinations, visual, 371.

Harlan's operation for symble-
pharon, 564 ; test for pretended
amaurosis, 394.

Harman's diaphragm test, 535.

Haselberg's test types, 394.

Hay fever, 70.

Heine's operation for glaucoma,
256.

Helmholtz's ophthalmoscope, 29.

Hemiachromatopsia, 3()9.

Hemianopic pupil, 3()9.

Hemianopsia, 343, 360 ; relative.
301 ; homonymous, 301 ; bi-
temporal. 301, 305; superior or
inferior, 301 ; altitudinal, 361 ;
nasal, 301, 3«)5 ; double, 361;
localisation of lesion in ca,ses of,
304 ; heteronymous, 305 ; transi-
tory, 390.

Hemiplegia, crossed, 501.

Hereditary ataxy (Friedrich's
disease), 382.

Hering's drop experiment, 473;
theory of colour sense, 11.

Hernia cerebri, 000.

Herpes cornea? febrilis, 131 ; herpes
zoster ophthalmicus, 548.

Hertel's exophthalmometer, 590.

Hess's operation for ptosis, 555, 558.

Heterochromia, 224.

Heterophoria, 391, 526 ; svmptoms
of, 532.

Heurteloup's artificial leech, 300, 322.

Hirschberg's operation for total
post-synechia, 209 ; method of
measuring strabismus, 513.

Hippus, 232.

Holmgren's colour test, 13.

Holth's operation for glaucoma, 250.

Home civil service, 027.
i Hordeolum, 545.

Hot eye, 104.

Hotz's operation for senile entro-
pion, 570.

Hyaline outgro\^ths for optic disc.
357.

Hyaloid artery, persistent, 312.

Hydrocephalus, 344, 377.

Hydrophthalmos, congenital, 260.

Hypermetropia, 428 ; definition and
optical causes, 428 ; senile, 429 ;
optical correction of, 430 ; de-
termination of degi-ee of, 431 ;
amplitude of accommodation in,
432 ; angle 7 in, 432 ; varieties
of, 432 ; prescribing glasses in,
435 ; far point in. 429.

Hyperphoria, 527.

Hypha^ma, 170, 211.

Hypopyon, 114.

Hysteria, nervous amblyopia in^
383.

Idiocy, amaurotic family, 375.
Indian civil service, etc., vision re-
quired for, 628.

<)43

INDEX.

Infantile paralysis, 378.

Insufficiency, muscular, 472.

Intorsion (wheel movement), 467.

Intra-muscular injections of mer-
cury, 183.

Intra-ocular tumours, 259.

Iridectomy, 225.

Iridencleisis (Holth's operation) for
glaucoma, 256.

Irideremia, 223.

Irido-cyclitis, 185.

Iridodialysis, 212.

Iridodonesis, 295.

Iridotomy, 292.

Iris, inflammation of, 173 ; injuries
of, 211 ; bombe, 175 ; abnor-
malities in colour of, 224 ; de-
hiscence of, 213 ; retroflexion of,
213 ; new growths of, 216 ; cysts
of, 216 ; solitary tubercle of,
216; sarcoma of, 216; malfor-
mations of, 223 ; coloboma of,
223 ; operations on, 225.

Iritis, 173; acute, 173; acute pri-
mary, symptoms of, 175 ; acute
primary, etiology of, 177; acute
primary, treatment of, 180 ; syphi-
litic, 177; gonorrhceal, 177;
tubercular, 178; rheumatic, 180 ;
chronic, 185; serous (or cyclitis),
259 ; plastic, 287.

Jacob's ulcer, 551.
Japanese muff warmers, 117.
Jequiritol, 81.
Jequirity, 79.

Kenneth Scott's operation for
senile entropion, 573.

Keratalgia, recurrent traumatic,
156.

Keratitis, 102 ; primary phlycte-
nular, 102 ; neuro - paralytic,
131 ; dendriform, 133 ; bullous,
135; fascicular, 103; filamentary,
135 ; aspergillina, 135 ; diffuse
interstitial or parenchymatous,
137, 143 ; specific, punctiform,
interstitial, 141 ; guttate or
nodular, 141 ; grating-like or
reticular, 141 ; discoid or annular,
142 ; disciform of Fuchs, 142 ;
tubercular, 143 ; punctate, 144 ;
punctata superficialis, 144 ; ri-
band-like, 145 ; striped, 286.

Keratoconus, 150.

Keratomalacia, 130, 141.

Keratoplasty, 161.

Knapp's operation for tumour of

optic nerve, 611 ; roller forceps.

78.
Koch's old tuberculin, 180.
Koch-Weekes bacillus, 53.
Komoto's operation for staphyloma.

149.
Kronlein's resection of orbit, 618.
Kuhnt's conjunctival flap, 121 ;

operation for senile entropion, 573.

Lacrimal apparatus, diseases of
the, 580.

Lacrimal gland, inflammation of
the, 592 ; tumours of the, 593 ;
extirpation of the, 594 ; tuber-
cular tumour of the, 594 ; cysts
of the, 594 ; symmetrical chronic
swelling of salivarv gland and,
594.

Lacrimal sac, blenorrhoea of, 586 ;
extirpation of, 588 ; treatment
with protargol and peroxide of
hydrogen, 588.

Lacrimation, 332.

Lagophthalmos, 504.

Lagrange's operation for glau-
coma, 252.

Lambkin's mercurial treatment,
183

Landry's disease, 383.

Lead-poisoning, 346.

Leber's disease, 347.

Leiter's tubes, 61.

Lens, crystalline, diseases of, 261 ;
dislocation of, 258, 294 ; opacity
of [see Cataract).

Lens measurer, 411.

Lenses, 401 ; spherical, 401 ; spheri-
cal images formed by, 405 ;
meniscus, 402 ; periscopic, 402 ;
optical defects of, 407 ; cylindri-
cal, 407 ; sphero-cylindrical and
toric, 408 ; numbering of, 409
recognition of spherical, 410
recognition of cylindrical, 410
decentration of, 412 ; prescribing
of cylindrical, 446 ; bifocal, 463.

Lenticonus, 295.

Leontiasis ossium, 597.

Leprosy, 179.

Leucaemia, 179.

Leucoma of cornea, 116, 160.

Light-sense, 10 ; Bjerrum's test for,
10 ; reflex, 229.

Lithiasis of conjunctiva, 96.

Lohlein's operation for cronea
transplantation, 162.

INDEX.

641

Lupus, of conjunrtiva, S('» ; of ov<^-

iids, 553.
LynipluidcMioma ot eyelids, 553.
Lymphoma of chorioid, 220 ; of

conjunctiva, 100; of eyelids, 553.

-AI.u-Li.A (conical), IKi, 160.

Macula lutea, 34, 38, 340 ; chorioi-
dal degeneration near the, 423 ;
ehorioidal exudation near the, 423.

.Maculo-cerebral degeneration, 376.

.Maddox's axis finder, 411; tangent
scale, 515 ; double prism, 529 ;
rod test, 530 ; wing test, 53 1 .

Magnet, Haab's Giant electro-, .309;
Snell's, 308.

Marginal blepharitis. 543.

Maxillary antrum, 614.

Measurement of convergent stra-
bismus, 513.

Megalopsia, 190.

Meibomian glands, 45 ; cysts, 546.

Membranous conjunctivitis, 6().

Meningitis, 376; tubercular, 344;
non-tubercular, 344 ; cerebro-
spinal, 344, 377 ; acute tubercular,
377; traumatic, 377.

Menstruation, suppression of, 345.

Metamorphopsia, 190, 315, 321.

Metre angle, the, 9.

Micropsia, 190, 464.

Migraine, 3 9 J.

^ligratory ophthalmitis, 210.

Mikulicz's disease, 594.

Miliary tubercular nodules, 144.

Millium, 547.

Mind blindness, 371.

Miosis, 214.

Miotics, 234.

Mirror, concave, 452 ; plane, 453.

Moebius' sign, 622.

Mole, or nsevus, 99.

Molluscum, 547.

Molluscum contagiosum, 547.

Motais' operation for ptosis, 555,
556.

Mouches volantes, 302.

Mucocele, 586.

Mules' operation, 148.

Muscse volitantes, 302.

Myasthenia gravis, 496.

Mydriasis, 214.

Mydriatics, 233.

Myelitis, 347, 382.

Myoclonic nystagmus, 540.

Myodesopsia, 302.

Myopia, or short sight, 414;
optical correction of, 416 ; diag-

nosis and determination of the
degree of, 417 ; amplitude of
acconnnodation in, 418; range
of accommodation in, 419; the
angle 7 in, 419 ; etiology of, 420;
simi)l(> or non-progreysive, 421 ;
spasmodic, 421 ; symptoms of,
421 ; pernicious, 422 ; the black
spot in, 425 ; management of, 425 ;
l)rescribing of glassesj in, 425 ;
operative cure of, 425.

Myopic crescent, 422.

Myopic eye, far point of the, 415.

Myosarcoma, 217.

Myotonia congenita, 382.

N^vus of eyelids, 547 ; of conjunc-
tiva, 99.

Nasal duct, stricture of, 583.

Navy, Royal, vision reqiiired for,
627.

Near point, 6.

Nebula of cornea, 115, 160.

Nervous amblyopia, 383.

Neuritis, peripheral, 346 ; here-
ditary optic, 347 ; retrobulbar,
or axial optic, 347 ; optic, asso-
ciated with cerel^ro-spinal rhinor-
rhoea, 349 ; axial, 349.

Neurofibroma, 553 ; neurofibroma-
tosis, 260.

Neuroma, plexiform, 545.

Neurosis, traumatic, nervous am-
blyopia in, 389.

Night blindness, 190, 392.

Nitrate of silver in conjunctivitis,
54.

Nuclear paralysis, 492.

Nystagmus, undulatory, 536 ; rhyth-
mic, 536 ; amblyopic or ocular,

' 537 ; coal miner's, 537 ; vestibular,
538 ; spontaneous, 539 ; in dis-
eases of nervous system, 539 ;
voluntary, 540 ;"^ hereditary, 540 ;
spasmus nutans, 540 ; myoclonic,
540 ; latent, 540.

Oblique illumination, 110.

(Edema, 541 ; angioneur o ic, 542 ;
solid, 542 ; elephantiasis lym-
phangioides, 542 ; elephantiasis
nostras, 542.

Opacities in refractive media, 35 ;
of the cornea, 160.

Opaque nerve fibres, 38.

Ophthalmia, 46 ; purulent, 58 ;
purulent prophylaxis, Crede's
method of, 60, 61 ; purulent, Lei

642

INDEX.

>er's tubes in,. ()1 ; metastatic,
gonorrhoeal, 05 ; granular, 70 ;
Egyptian, 70 ; military, 70 ; acute
granular, 73 ; chronic granular,
73; nodosa, 86, 179; electric,
333; tarsi, 543 ; neonatorum, 58 ;
phlyctenular, 102.
Ophthalmitis, sympathetic, 193,
195 prognosis in, 202; treatment
of, 203 ; prophylactic operations
for, 206 ; therapeutic operations
for, 207 ; optical operations for,
208 : pathology of, 209

Ophthalmoplegia externa, 492 ; in-
terna, 492 ; universa, 492.

Ophthalmoplegic migraine, 491.

Ophthalmoscope, the, 26 ; Helm-
holtz's, 29 ; modern, 29 ; methods
of ushig, 30 ; direct method, 30 ;
indirect method, 31 ; Gullstrand's,
33 ; electric, 36 ; estimation of
refrav-'tion with, 447 ; refraction,
449.

Optic amnesia, 371.

Optic atrophy, hereditary, 34 7 ;
simple, 353; consecutive, 35 3;
chorioido-retinal, 354 ; primary ,
354 ; from poisoning with organic
preparations of arsenic, 356 ;
treatment of, 356,

Optic axis, 3 ; disc, or papilla, 36 ;
ganglia, primary, 362.

Optic nerve, atrophy of, 353 ;
chorioido-retinal atrophy of, 354 ;
injuries of, 357 ; tumom-s of,
609 ; examination of, 34 ; diseases
of, 341.

Optic neuritis, 199, 341 ; hereditary,
347 ; retrobulbar, or axial, 347 ;
associated with cerebro-spinal
rhinorrhoea, 349.

Optical defects in lenses, 406.

Optics, elementary, 396.

Ora serrata, 40.

Orbicular sign in hemiplegia, 505.

Orbicularis muscle, clonic cramp,
of, 553 ; tonic cramp of, 554.

Orbit, diseases of the, 596 ; perios-
titis of the, 598 ; caries of the,
600 ; injuries of the, 600 ; em-
physema of the, 602 ; tumours of
the, 602 ; carcinoma of the, 608 ;
cysts of the, 605, 606 ; sym-
metrical tumours of ^the, 608 ;
angiomata of the, 607 ; exos-
toses of the, 607 ; temporary re-
section of outer wall of (Kron-
lein's op,), 618.

Orbital cellulitis, 597 ; cysts, 605.

Orbital muscles and their derange-
ments, 466 ; paralysis of, 476 ;
cerebral^paralysis of, ,497.

Orientation, 471.

Orthophoria, 526.

Osteo-sarcoma of chorioid, 220.

Oxycephaly^ 597.

Palpebral cliromidrosis, 548.

Pannus, 71, 75.

Panophthalmitis, 192, 196. y

Papilla, optic, cupping^of , 238 ; con-
gestion, 342 ; and intracranial
tumours, 343.

Papilhtis, 199.

Papillcedema, 317, 342.

Papilloma, or papillary fibroma of
conjunctiva, 100.

Paracentesis of anterior^chamber,
118 ; in sympathetic ophthal-
mia, 208.

Parallax, 37, 239.

Paralysis of accommodation, 463 ;
of orbital muscles, 476 ; of external
rectus of left eye, 478 ; of superior
oblique of left eye, 480 ; of third
nerve, 481, 500 ; measurement of
degree of, of orbital muscles, 488 ;
of orbital muscles, causes of, 488 ;
intermitting of third nerve of one
eye, 491 ; of third nerve, with
cyclical spasm, 492 ; nuclear, 492 ;
nuclear, chronic, 494 ; conjugate
lateral, 495 ; fascicular, 496 ;
cerebral, of orbital muscles, 497 ;
of fourth nerve, 503 ; of sixth
nerve, 503 ; of seventh nerve,
504 ; of fifth nerve, 505 ; rheu-
matic, 488 ; ^and ataxy of orbital
muscles, 380 ; agitans, 378.

Paralytic strabismus, 472 ; ectro-
pion, 577.

Parasitic disease of retina, 335.

Parinaud's conjunctivitis, 85.

Paster lenses, 462.

Pemphigus of conjunctiva, 89.

Perimeter method of measuring
strabismus, 516.

Perimetry, 17.

PeripheralJ neuritis, 346.

Peritomy, 81.

Peroxide of hydrogen for lacrimal
sac, 588.

Persistent hyaloid artery, 312 ;
pupillary membrane, 223.

Pfiiiger's"method of tarsoraphy, 562.

Phlj^ctens, niultiple, or miliary, 103.

INDEX.

fi43

Phlyctenular conjunctivitis and

keratitis. 102.
Photometer, 10.
Photophobia, 104, 3.32.
Photopsifp, 387.
Phthoiriasis cilioruin, 545.
Phthi.sis bulbi, 170.
Physioloofica] excavation of tlio

papilla, 37.
Pigment spots in sclerotic, 108.
Pinguecula. 93.
Placedo's disc, 447.
Plane glass, 397.

Pl(>xiform neuroma of eyelids, 553.
Plica semilunaris, 42.
Pneumococcus, 53.
Polioencephalitis, chronic, superior,

494.
Pollentine, 70.
Polycoria, 223.
Polyopia, 265.

Polypus and granuloma of con-
junctiva, 100.
Post-operative conjunctivitis, 280.
Posterior staphj-^loma, 422.
Pre-retinal haemorrhages, 320.
Presbyopia, 460.

Priestley Smith's scotometer, 20 ;
method of measuring strabismus,
514 ; heteroscope, 518 ; opera-
tion for tarsoraphy, 562.
Prisms, 397 ; numbering of, 398 ;
uses of, 401 ; prescribing of,
401 ; tests with, 528 ;'^^Maddox's
double, 529.
Projection of light, 24, 276.
Proptosis, 596.

Protargol, 54 ; for lacrimal sac, 588.
Protective glas-ses, 413.
Prothesis oculi, 206. i
Pseudo-glioma, 298 ; hypopyon,

175.
Pterygium, 93.

Ptosis, 481, 554'; sympathetic,
501 ; paralytic, 554 ; congenital,
555, 56); adiposa, 555, 560;
operations for, 555 ; hysterical,
560.
Punctate deposits on cornea, 144.
Punctum lacrimale, malposition of,

580 ; stenosis of, 581.
Punctum proximum, 6.
Punctum remotum, 6 ; in H., 429 ;

in M., 415.
Pupil, 229 ; hemianopic, 369 ; con-
traction[of, 229; dilatation of,' 230 ;
action of mydriatics on, 233 ;
action of niiotics on, 234 : Argyll

Robertson, 381 ; symptom, Wer-
nicke's, 369 ; sensory reflex, 231.
Pyramidal cataract, 65.

QuiNiNR amaurosis, 330.

Radhtm. 81.

Railway spine, 383.

Range of accommodation, 6.

Real inverted imago of convex
lens, 405.

Red vision, 394.

Reflection, laws of, 26.

Refraction, 4, 396 ; normal, 4 ;
index of, 397 ; abnormal and ac-
commodation, 414 ; estimation
of, 447 ; ophthalmoscope, 449.

Remy's diploscope, 535.

Resorcin, 56.

Retina, diseases of, 313 ; inflam-
mation of, 314 ; capillary angio-
matosis of, 323 ; obstruction of
central artery of, 325 ; atropliies
and degenerations of, 328 ; gyrate
atrophy of, 330 ; blinding of by
directsunliglit, 331 ; blinding of by
electric light, 333 ; tumours of the,
334 ; glioma of the, 334 ; tubercle
of the, 335 ; cysticercus under the,
335 ; detachment of the, 336,
424 ; traumatic affections of the,
339 ; traumatic anaesthesia of the,
339 ; traumatic oedema of the,
340 ; haemorrhage in, at yellow
spot, 424 ; hyperaemiaof th(\ 313.

Retinal adaptation, 11 ; vessels, 39 ;
diseases of, 323 ; haemorrhages,
320 ; affections in diabetes, 318.

Retinitis, 314; albuminin-ica, 316;
syphilitic, 314; loucaemic, 319;
metastatic, 319 ; exudative, 322 ;
haemorrhagica externa (Coats),
322 ; circinata, 322 ; proliferans,
301, 322; hfeniorrhagic, 327 j
piy:mentosa. 328, 392 ; punctata
•^'Ijpscens, 330 ; atrophicans cen-
tralis of Kuhnt, 340.

Retinoscopy, 452 ; with plane
mirror, 455, 459 ; with concave
mirror, 456.

Retro-bulbar nem-itis, 345, 347.

Retroflexion of iris, 213.

Rheumatic paralysis, 488.

Rhinorrhoea, persistent cerebro-
spinal, with optic neuritis, 349.

Rodent ulcer of eyelids, 551.

Romer's"''treatment of serpiginous
!ilcers,^127.

044

INDEX.

Rontgen rays, Mackenzie David-
son's method for employing, 305.

Rontgen rays, treatment of rodent
ulcer, 552.

Royal Army iNIedical Corps, 625.

Royal Irish Constabulary, vision re-
quired for, 631.

Royal Navv, vision required for.
627.

Sach's operation for foreign body
in vitreous, 311.

Ssemisch's incision for corneal ulcers,
127.

Sarcoma carcinomatosum of uveal
tract, 220 ; of conjunctiva, 100 ;
of eyelids, 553.

Schiotz's tonometer, 236.

Schlemm's canal. 212.

Scissors movement in retinoscopv,
459.

Sclerectomy, anterior, 252 ; with
trephine, 253.

Scleritis. brawny or annular, 168 ;
deep, 166.

Sclerosis, disseminated, of brain
and cord, 372; dii^use, of brain.
374 ; disseminated, 346 ; of
retinal vessels, 323.

Sclerotic, blue colour of, 172 ;
diseases of the, 164 ; syphilitic
gumma of the. 167 ; tubercle of
the, 167 ; tumours of the, 168 ;
pigment spots in, 168 ; injuries
of, 168 ; ruptures of the. 168 ;
perforating wounds of the. 170 ;
staphyloma of the. 171 ; con-
genital defect of the, 172 ; punc-
ture of, in detached retina, 338 ;
coloboma of the, 172 ; transillu-
minator, 218.

Sclerotomy, posterior, 250.

Scopolamine, 181.

Scotoma, central, 22 ; paracentral,
22 ; annular or ring, 22 ; posi-
tive, 24 ; negative, 24 ; absolute.
24 ; relative, 24 ; crescentic
para-central, 242 ; scintillating.
390.

Sense of fusion, 473.

Seventh nerve, paralysis of, 504.

Shadow test, or retinoscopy, 452.

Sideroscope, 304.^307.

Siderosis, 224.
Sight, sense of, 10.
Sixth'nerve, paralysis of, 503.
Skin^ transplantation, Wolfe 's
method of, 576.

Snell's electro-magnet, 308.

Snellen's coloured types, 394 ; oper-
ation for entropion, 569 ; sutures,
572.

Snow-blindness, 332.

Solid oedema, 542.

Sophol, 54.

Spaces of fontana. 246.

Spasmus nutans, 540.

Sphenoid bone and antrum, diseases
of the, 614.

Spherical aberration, 406.

Spinal amaurosis, 354.

Spinal cord, diseases and injuries of,
379.

Sporotrichosis, 86, 179.

Spring catarrh, 87.

Staphyloma of cornea. 146 ; partial,
64 ; total 64, 147 ; leucomatous.
147 ; operations for, 147 ; pos-.
terior, 422 ; of sclerotic, 171 ;
anterior or ciliary, 171 ; eqvia-
torial, 171.

Stellwag's sign, 621.

Stevens' phorometer, 529.

Stilling's colour test. 14.

Stomach, haemorrhages for, 357.

Strabismometer, tangent, 517.

Strabismus, 472 ; apparent, 472 ;
paralytic. 472 ; concomitant. 472;
latent, 472 ; fixus, 506 ; conver-
gent, concomitant, 435, 506, 517 ;
non-paralytic, 506 ; single vision
in concomitant, 511 ; clinical
varieties of concomitant con-
vergent, 513 ; periodic. 513 ; per-
manent alternating, 513 ; perma-
nent monolateral, 513 ; measure-
ment of convergent, 513 ; measure-
ment of, 513-517.

Strabismus, treatment of concomi-
tant convergent, 517 ; operative,
519, 520 ; optical, 517 ; orthoptic,
518; subconjunctival operations
for, 522 ; concomitant, divergent,
525.

Streptothrix in lower canaliculus,
582.

Stye, 545.

Subconjunctival cysticercus, 98.

Subconjunctival ecchymosis, 91.

Subconjunctival injections : oxy-
cyanate of mercury, 120 ; saline
solution, 120, 300 ; potassium
iodide, 55.
Subconjunctival serous effusion, 91.
Subcortical alexia, 370.
Subhyaloid haemoi-rhages, 320.

INDEX.

645

Sulcus or fornix of coiijunctiv^a, 42.
Sulphate of zinc in conjunctivitis,

Synibleplmron, ()J>, 74, l>2, 562 ;
Harlan's operation for, 561 ;
Teale's operation for, 563.

Sympathetic irritation, 193, 194;
disseminated chorioiditis, 201 ;
ophthahnitis, 193, 195; ophthal-
mitis, prophylactic operations for,
206 ; ophthahnitis, oj^tical opera-
tions for, 209; ptosis, 501.

Svnchysis, 299, 302 ; scintillans,
' 303.

Synechia?, posterior, 174, 199;
complete posterior, 175, 258 ; cir-
cular posterior, 175; ring, 175,
258; total posterior, 175.

Synkinesis, 229.

Syphilis in optic neuritis, 345.

Syphilitic affections of eyelids, 551;
gumma of ciliary body, 188 ;
tarsitis, 551.

Syringomyelia, 382.

Tabes dorsalis, 347, 379 ; pupillary
alterations in, 381.

Tangent strabismometer, 517.

Tarsal cyst, 546.

Tarsitis syphilitic. 551.

Tarsoraphy, 561 ; Priestly Smith's
method, 562 ; Pfliiger's method,
562.

Tattooing cornea, operation of, 160.

Teale's operation for symblepharon,
563.

Telangiectic tumours O'f eyelids, 547.

Tenesmus, 182.

Tenonitis, 598.

Tenotomy for concomitant con-
vergent strabismus, 520.

Tension, intra-ocular, in glaucoma,
236.

Third nerve, paralysis of, 481.

Thomsen's disease, 382.

Thrombosis of central artery of
retina, 325 ; of retinal -vein, 327 ;
of cavernous sinus, 502, 598.

Tonometer, Schiotz's, 236.

Tower skull, 344.

Trachoma, 70 {see (h-anular Oph-
tliahnia) ; cells, 71; acute, 73;
chronic, 73 ; treatment of by
caustics, 77 ; mechanical and
operative, 78; jequiritol, 81 ; in-
fusion of jequirity, 79 ; trichiasis
in, 74, 565.

Trichiasis, 565.

Tul).M-clc of uveal tract, 220 ;
sclerotic, 167; retina, 335.

Tubercular cyclitis, 189; menin-
gitis, 344 ; disease of conjtmc-
tiva, 84.

Tuberculin, 187.

Tumours, malignant, of conjunc-
tiva, 100 ; of the caruncle, 101 ;
of the sclerotic, 168; intra-ocular,
259 ; telangiectic, 547 ; of lacri-
mal gland, 593 ; of lacrimal
gland, tubercular, 594 ; of orbit,
602 ; symmetrical of orbits, 608 ;
of optic nerve, 609.

Ulceration of cornea, infantile,
with xerosis of conjunctiva, 130.

Ulcers, of the cornea, simple, 122;
deep, 123; serpiginous, 1 24 ; ser-
piginous, Romer's treatment of,
127; serpiginous, Stemisch's treat-
ment of, 127 ; pneumococcus, 124 ;
Saemisch's, 124 ; marginal or ring,
128 ; diplobacillary, 128 ; rodent,
129; Mooren's, 'l29 ; of the
cornea, 258 ; of the conjinictiva,
87.

Uterus, haemorrhages from the, 357.

Uveal tract, diseases of, 173 ; in-
jiu-ies of, 211 ; malformations of,
223 ; new growths of, 216.

Uveitis, chronic, 186 ; purulent,
196.

Vaccine, atoxic gonococcal, 06 ;
autogenous, 186.

Vaccine vesicles on eyelids, 551.

Van Milligan's operation for trichi-
asis, 567.

Vascular na>vus, 99 ; vernal con-
junctivitis, 87.

Vertige paralysant, 494.

Vision, acuteness of, 14; field of,
17 ; defects in, 20 ; effect of prism
on binocular, 400 ; field of, con-
centric contraction of, 385.

Visual aphasia, 370 ; hallucina-
tions, 371 ; line, 3.

Vitreous humour,, diseases of, 298 ;
purulent inflammation of, 298 ;
non-purulent inflammation of,
299 ; varieties of opacities in, 299 ;
haemorrhage in, 301 ; fluidity of, or
synchysis, 302 ; foreign bodies in,
303; cysticercus in, 311; blood
vessels in, 312 ; synchysis scin-
tillans of, 303 ; mouches volan-
tes in, 302 ; prolapse of, 284 ;

646

INDEX.

detection of foreign bodies in,
304 ; by Mackenzie Davidson's
method, 305 ; by sideroscope,
304 ; removal of foreign bodies
in the, 308.

Von Graefe's sign in exophthalmic
goitre, 621.

Von Hippel's disease, 323.

Waxy disc, 354.

Weber's probes, 585.

Weeks' operation for xeroph-
thalmos, 617.

Wenzel's operation for total pos-
terior synechia, 209.

\A'ernicke's pupil-symptom, 369.

Wolfe's method of skin trans-
plantation, 576.

Wood alcohol, 352.
Word-blindness, 370 ; congenital.

370.
Worth's amblyoscope, 518; devio-

meter, 515.

[ Xanthelasma, 547.
i Xerophthalmos, 69, 96 ; after enu-
cleation, 615.

Xerosis, 74, 96 ; bacillus. 48.

X-rays, 81.

Young-Helm HOLTZ theory of
colour vision, 11.

Ziegler's iridotomy operation, 292.

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