Bought of .: v^.T. KEENER CO. Medical BooUsellers, 404 North 8Th Street, St. Louis, Mo. THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA LOS ANGELES GIFT Mrs, Janet White St, John's Hospital <{/„^ ///^/-^^ >J DISEASES OF THE EYE. A HANDBOOK DISEASES OF THE EYE AXD THEIR TREATMENT HENRY R. JSWANZY, A.M., M.B., F.R.C.S.I. SURGEON TO THE NATIONAL EYE AND EAR INFIRMARY, AND OPHTHALMIC SURGEON TO THE ADELAIDE HOSPITAL, DUBLIN; EXAMINER IN OPHTHALMIC SURGERY IN THE UNIVERSITY OF DUBLIN, AND IN THE ROYAL UNIVERSITY OF IRELAND FOURTH EDITION WITH ILLUSTRATIONS PHILADELPHIA P. BLAKISTON, SON & CO 1012 WALNUT STREET 1892 Copyright, 1892, by P. Blakiston, Son & Co. Phess of Wm. F. Fell & Co 1220-24 Sansom St.. philadelphia. WW loo I DEDICATE THIS BOOK TO THEODORE LEBER, PROFESSOR AT THE UXIVERSITT OF HEIDELBERG, AS A MARK OF MY ADMIRATION FOR HIS EMINENT SERVICES TO OPHTHALMOLOGY, AND OF MY SINCERE REGARD. PREFACE TO THE FOURTH EDITION. The Third Edition of this book was published in October, 1890, and I am gratified that the work continues to find favor, not only with students, for whom it is mainly intended, but also with practitioners. The book has now again been revised throughout, and brought up to date. In an Appendix, Holmgren's Method for Testing the Color Sense has been described in greater detail than before. Some new illustrations have been added. The great difficulty of an author in the preparation of a book like this consists in " Saying not all he might, but all he ought." It is his duty to give a succinct and practical account of his subject in its most modern aspect, without weighting his pages with excessive detail and prolonged dis- cussion. This has been my aim. For deeper and wider infor- mation, larger handbooks, and original monographs, must be consulted. 23 Meriox Square, October, 1892. CONTENTS. CHAPTER I. PAGE Some Elementary Optics — Numbering of Trial-Lenses and Spec- tacle Glasses — Normal Refraction and Accommodation — The Metre Angle — The Angle Gamma — The Sense of Sight (Light- Sense, Color-Sense, Form-Sense) — The Field of Vision ... 1 CHAPTER IL ABXORMAL REFRACTION AND ACCOMMODATIOX. Hjpermetropia — Correction of H. — Amplitude of Accommodation in H. — Angle Gamma in H — Cramp of Ciliary Muscle in H. — Accommodative Asthenopia in H. — Internal Strabismus in H. — The Prescribing of Spectacles in H 25 Myopia — Determination of Degree of M. — Amplitude of Accom- modation in M. — Angle Gamma in M. — Complications of Pro- gressive M. — Management of M. — The Prescribing of Specta- cles in M 31 Astigmatism — Symptoms of As. — Estimation of Degree of, and Correction of As. — Lental As. — Irregular As 39 Anisometropia 49 Anomalies of Accommodation — Presbyopia — Paralysis of Accom- modation — Cramp of Accommodation 49 CHAPTER III. THE OPHTHALMOSCOPE. Why Necessary — Helmholtz's Ophthalmoscope — Modern Ophthal- moscope — Direct Method — Indirect Method 56 Estimation of the Refraction by aid of the Ophthalmoscope — Direci Method — Retinoscopy 63 Focal Illumination , . , 76 ix X CONTENTS. PAGF. The Normal Fundus Oculi as seen with the Ophthalmoscope — The Optic Papilla — The Retina — The Macula Lutea — The General Fundus Oculi — The Retinal Vessels 77 CHAPTER IV. DISEASES OF THE CONJUKCTIVA. Hyperaemia — Conjunctivitis — Catarrhal, or Simple Acute Conjunc- tivitis — Follicular Conjunctivitis — Spring Catarrh — Granular Conjunctivitis, Granular Ophthalmia, or Trachoma — Acute Granular Ophthalmia— Chronic Granular Ophthalmia — Acute Blennorrhoea of the Conjunctiva, or Purulent Ophthalmia — Croupous Conjunctivitis— ^Diphtheritic Conjunctivitis — Con- junctival Complication of Smallpox — Amyloid Degeneration — Tubercular Disease of the Conjunctiva — Lupus — Pem- phigus — Xerophthalmos — Pterygium — Pinguecula — Subcon- junctival Ecchymosis— Polypus — Dermoid Tumors — Syphilitic Disease of the Conjunctiva — Papilloma, or Papillary Fibroma — Epithelioma — Sarcoma — Simple Cysts — Subconjunctival Cys- ticercus — Lithiasis — Injuries of the Conjunctiva 82 CHAPTER V. PHLYCTENULAR, OR STRUMOUS, CONJUNCTIVITIS AND KERATITIS. Solitary, or Simple, Phlyctenula of the Conjunctiva — Multiple, or Miliary, Phlyctenula of the Conjunctiva — Modes of Secondary Corneal Affection — Primary Phlyctenular Keratitis— Different Forms of Same — Symptoms of Phlyctenular Keratitis — Causes of Phlyctenular Ophthalmia — Treatment 123 CHAPTER VI. THE DISEASES OF THE EYELIDS. Eczema — Herpes Zoster Ophlhalmicus — Primary Syphilitic Sores — Secondary Syphilitic Sores — Vaccine Vesicles— Rodent Ulcer — Marginal Blepharitis (Ophthalmia Tarsi)— Phtheiriasis Cili- orum — Hordeolum (Stye) — Chalazion (Meibomian Cyst, Tarsal Tumor) — Mi Ilium — Molluscum — Njevus — Xanthelasma — Chro- midrosis — Epithelioma, Sarcoma, and Lupus — Clonic Cramp of the Obicularis Muscle — Blepharospasm — Ptosis— Operations for its Cure— Lagophthalmos — Symblepharon — Blepharophi- CONTENTS. XI PAGE mosis — Canthoplastic Operation — Distichiasis and Trichiasis — Operations for their Cure — Entropium — Operations for its Cure — Spastic Entropium — Senile Entropium — Operations for its Cure — Ectropium — Operations for its Cure— Ankyloblepharon — The Restoration of an Eyelid — Injuries — Ecchymosis — Epi- canthus — Congenital Coloboma 132 CHAPTER Vir. THE DISEASES OF THE LACHRYMAL APPARATUS. Malposition of the Punctum Lachrymale — Stenosis and Occlusion of thePunctum Lachrymale — Obstruction of the Canaliculus — Stric- ture of the Nasal Duct — Blennorrhoea of the Lachrymal Sac — Acute Dacryocystitis — Dacryoadenitis — Hypertrophy of the Lachrymal Gland 1T4 CHAPTER VIIL THE DISEASES OF THE CORNEA. Inflammations of the Cornea — (a) Ulcerative Inflammations of the Cornea — Simple Ulcer — Deep Ulcer — Ulcus Serpens — Rodent Ulcer — Marginal Ring Ulcer — Absorption L^lcer — Neuro- Para- lytic Keratitis — Infantile L'lceration of the Cornea with Xerosis of the Conjunctiva — Herpes — Thread like Keratitis — Bullous Keratitis — Dendriform Keratitis 184 (6) Non Ulcerative Inflammations of the Cornea — Abscess — Dif- fuse Interstitial Keratitis — Keratitis Punctata — Sclerotizing Opacity — Riband-like Keratitis . , 205 Ectasies of the Cornea — Staphyloma Corneas — Conical Cornea . . 211 Tumors of the Cornea 219 Injuries of the Cornea — Foreign Bodies — Losses of Substance . . 219 Opacities of the Cornea— Nebula, Macula, Leucoma — Sclerotizing Opacity — Arcus Senilis 221 CHAPTER IX. THE DISEASES OF THE SCLEROTIC. Inflammations of the Sclerotic — Episcleritis — Deep Scleritis — In- juries of the Sclerotic — Tumors of the Sclerotic 225 XU CONTENTS. CHAPTER X. THE DISEASES OF THE UVEAL TRACT. PAGE Iritis — Simple Plastic Iritis — Serous Iritis— Parenchymatous (in- cluding Purulent) Iritis 230 Injuries of the Iris — Punctured Wounds — Foreign Bodies — Irido- dialysis — Retroflexion — Rupture of the Sphincter Iridis — Traumatic Aniridia — Anteversion — Traumatic Mydriasis . . . 240 New Growths of the Iris — Cysts — Granuloma — Tubercle — Sarcoma 242 Congenital Malformations of the Iris — Heterophthalmos — Corec- topia — Polycoria — Persistent Pupillary Membrane — Coloboma — Irideremia 243 Operation on the Iris — Iridectomy — Iridotomy 245 Cyclitis — Plastic Cyclitis — Serous Cyclitis — Purulent Cyclitis— In- juries of the Ciliary Body — New Growths of the Ciliary Body 247 Choroiditis — Disseminated Choroiditis — Syphilitic Choroido-Retin- itis — Central Senile Guttate Choroiditis — Central Choroiditis — Central Senile Atrophy of the Choroid — Purulent Choroiditis — Posterior Sclero-Choroiditis — Detachment of the Choroid . 250 Injuries of the Choroid — Foreign Bodies — Incised Wounds — Rup- ture — New Growths of the Choroid — Sarcoma — Carcinoma — Tubercle — Sarcoma Carcinomatosum — Myosarcoma— Osteo- sarcoma 256 Congenital Defects of the Choroid — Coloboma — Albinismus . . . 259 Sympathetic Ophthalmitis 260 CHAPTER XI. THE MOTIONS OF THE PUPIL IN HEALTH AND DISEASE. The Size of the Pupil in Health — Contraction of the Pupil — Dila- tation of the Pupil 272 The Action of the Mydriatics and Myotics on the Pupil 279 The Size of the Pupil in Disease — Myosis — Mydriasis ... • . . 280 CHAPTER XII. GLAUCOMA. Primary Glaucoma — Chronic, or Non-Inflammatory, Glaucoma- Acute, or Inflammatory, Glaucoma — Glaucoma Fulminans — Sub-Acute Glaucoma — Etiology — Pathology — Treatment . . 285 Secondary Glaucoma — Hemorrhagic Glaucoma 305 Congenital Hydrophthalmos 307 CONTENTS. Xlll CHAPTER XIII. THE DISEASES OF THE CRYSTALLINE LENS. PAGE Complete Cataracts — Senile Cataract — Progress, Pathogenesis, and Etiology — Treatment 309 Complete Cataract of Young People — Diabetic Cataract — Complete Congenital Cataract 316 Partial Cataracts — Central Lenta! Cataract — Zonular, or Lamellar, Cataract — Anterior Polar, or Pyramidal, Cataract — Fusiform, or Spindle-Shaped, Cataract 317 Secondary Cataract — Posterior Polar Cataract — Total Secondary Cataract . . . • 319 Capsular Cataract 320 Traumatic Cataract . • 320 Operations for Cataract — Extraction of Cataract — Linear Extrac- tion — The Modified Peripheral Linear Extraction — The Three Millimetre Flap Operation — Cataract Extraction without Iri- dectomy - • 328 Discission or Dilaceration — Suction Operation — Secondary Cataract and its Operation — Capsulotomy — Iridotomy 346 Dislocation of the Crystalline Lens — Lenticouus — Aphakia ... 351 CHAPTER XIV. • THE DISEASES OF THE VITREOUS HUMOR. Purulent Inflammation — Other Inflammatory AflFections — Opacities — Muscse Volitantes — Fluidity (Synchysis) — Synchysis Scintil- lans — Foreign Bodies — Cysticercus — Persistent Hyaloid Artery — Detachment 355 CHAPTER XV. THE DISEASES OF THE RETINA. Purulent Retinitis — Hemorrhagic Retinitis — Apoplexy of the Re- tina — Retinitis Albuminurica — Retinal Affections in Diabetes — Retinitis Leucsemica — Syphilitic Retinitis — Quinine Amaurosis — Retinitis Pigmentosa— Retinitis Punctata Albescens — De- velopment of Connective Tissue in the Retina— Detachment of the Retina — Cysticercus under the Retina— Aneurism of the Central Artery of the Retina — Embolism of the Central Artery of the Retina — Thrombosis of the Central Artery of the Retina — Glioma of the Retina— Blinding of the Retina by Direct Sun- light — Neurasthenic Asthenopia, or Retinal Anaesthesia — Trau- XIV CONTENTS. PAGE matic Anaesthesia of the Retina — Commotio Retinae, or Trau- matic (Edema of the Retina — Hyperesthesia of the Retina . . 365 CHAPTER XVI. THE DISEASES OF THE OPTIC NERVE. Optic Neuritis (Papillitis), due to : — Cerebral Tumors — Tubercular Meningitis — Acute Myelitis — Hydrocephalus — Tumors of the Orbit — Inflammatory Processes in the Orbit — Exposure to Cold — Suppression of Menstruation — Chlorosis — Syphilis — Rheuma- tism — Lead Poisoning — Multiple Sclerosis — and to Hereditary, and Congenital, Predisposition 389 Chronic Retro-bulbar Neuritis, or Central Amblyopia (Toxic Ambly- opia) — Optic Neuritis Associated with Persistent Dropping of Watery Fluid from the Nostril 395 Atrophy of the Optic Nerve, due to : — Optic Neuritis — Pressure — Embolism of the Central Artery of the Retina — Syphilitic Re- tinitis, Retinitis Pigmentosa, Choroido-Retinitis, and to Dis- ease of the Spinal Cord (Spinal Amaurosis) — Optic Atrophy as a Purely Local Disease 399 Tumors of the Optic Nerve— Hyaline, or Colloid, Outgrowths- Injuries of the Optic Nerve 402 Glycosuric Amblyopia — Amblyopia due to Hemorrhages from the Stomach, Bowels, or Uterus 403 CHAPTER XVII. AMBLYOPIA AND AMAUROSIS DUE TO CENTRAL AND OTHER CAUSES. Hemianopsia — Arrangement of the Cortical Visual Centres, their Relations to the Retina, and the Course of the Optic Fibres between these two points — Localization of the Lesion in Hemianopsia — Alexia, or Word-Blindness — Dyslexia — Soul- Blindness, Psychical Blindness, or Mind-Blindness — Congenital Amblyopia — Reflex Amblyopia — Hysterical Amblyopia — Nyc- talopia — Uraemic Amblyopia — Snow-Blindness — Pretended Amaurosis — Erythropsia 407 CHAPTER XVIII. THE MOTIONS OF THE EYEBALLS AND THEIR DERANGEMENTS. Actions of the Orbital Muscles — Inclination of the Vertical Meri- dian in the Several Principal Positions — Muscles called into Action in the Several Principal Positions 424 CONTENTS. XV PAGE Paralysis of the Orbital Muscles— General Symptoms — Paralysis of the External Rectus — Paralysis of the Superior Oblique — Paralysis of the Internal Rectus, Superior Rectus, Inferior Oblique and Levator Palpebise— Ophthalmoplegia Externa, or Nuclear Paralysis — Cerebral Paralysis of Orbital Muscles — The Localizing Value of Paralyses of Orbital Muscle in Cerebral Disease 429 Convergent Concomitant Strabismus — Causes — Single Vision in — Amblyopia of Squinting Eye- Clinical Varieties of — Measure- ment of — Mobility of Eye in — Treatment — Orthoptic Treat- ment — Operative Treatment — Tenotomy — Advancement of External Rectus — Dangers of the Strabismus Operation — Treatment Subsequent to Operation 453 Insufficiency of the Internal Recti, and Divergent Concomitant Strabismus — Muscular Asthenopia — Treatment — Operative Treatment 477 Nystagmus 483 CHAPTER XIX. THE DISEASES OF THE ORBIT. Orbital Cellulitis — Periostitis of the Orbit — Caries of the Orbit — Injuriesof the Orbit — Tumors of the Orbit — Diseases of Neigh- boring Cavities — Hernia Cerebri — Exophthalmic Goitre . . . 484 Appendix I. — Holmgren's Method for Testing the Color-Sense . . 499 Appendix II. — Regulations as to Defects of Vision which Disqualify Candidates for Admission into Civil, Naval and Military Ser- vices, the Royal Irish Constabulary, and the Mercantile Marine 502 Index 607 TO THE STUDENT. You should read carefully Chapters I, IT, and III, omitting at first the small print, either before, or immediately on, joining the Ophthal- mic Hospital, or Department. n. R S. DISEASES OF THE EYE. CHAPTER I. Some Elementary Optics — Numbering of Trial- Lenses and Spectacle Glasses — Normal Refraction and Accommodation — The Metre Angle —The Angle Gamma— The Sense of Sight (Light-Sense, Color- Sense, Form-Sense) — The Field of Vision. SOME ELEMENTARY OPTICS. Refraction. — The light emitted by a luminous point is propa- gated in all directions in straight lines, which are called " rays." A ray of light, passing from one medium into another of different density, becomes deviated in its path, and is said to be " refracted." The phenomenon itself is called " refraction." A ray of light (a h, Fig. ] ) falling on ^^^^ -^ a prism (Pj undergoes refraction in its passage through it ( 5 c), and again on its exit at the oppo- site side (c cOj JD each instance the deviation being toward the base of the prism. An observer who is placed at d, so as to receive into his eye the emerging ray, j^rojects, or thinks he sees, at a', in a prolongation of d c, the object from which the ray comes; that is, displaced toward the apex of the prism. The deflection which a ray undergoes by passing through a prism increases with the size of the angle at the apex of the latter. Prisms are described as being of 1°, 2°, 3°, etc., accord- ing to the size of this apex, or refracting angle.* * It has been proposed to measure prisms for ophthalmic practice 1 DISEASES OF THE EYE. Fig. 2. Convex and concave lenses may be regarded as being com- posed of prisms : convex lenses of prisms placed with their bases together (Fig. 2, A) ; con- cave lenses of prisms with their edges together (Fig. 2, B). Consequently, con- vex lenses cause pencils of rays which pass through them to converge, while concave lenses produce divergence of the rays. The Principal Axis of a lens is a line (P F, Fig. 3) passing through the centres of curvature of both its surfaces. The Optical Centre of a lens is a point through which the rays must pass in order that they may not undergo deviation.* Fig. 3. Any rays passing through the optical centre, except the prin- cipal ray or axis, are called Secondary Rays. All the other rays of the pencil undergo refraction. Convex Lenses (Fig. 3) bring parallel rays of light (a b P c either according to their angle of minimum deviation, by prism-dioptries, or by metre-angles, but none of these methods seem to be free from objection, or to offer any marked advantage over the current method. * Although sufficient for practical purposes, this is not theoretically correct, as all secondary rays passing through the optical centre are slightly deviated, but remain parallel to their original direction. Strictly speaking, the principal axis is the only one which undergoes no deviation. SOME ELEMENTARY OPTICS. 3 c/, Fig. 3) passing through them to a focus at a point (F) sl cer- tain distance on the other side. This point is called the Principal Focus of the lens, and the distance from it to the lens is termed the Focal Length of the lens. The more curved the surface of the lens, the shorter will be its focal length, and the more " pow- erful " the lens. Rays diverging from a light placed at F, Fig. 4. and falling on the lens, are made parallel when they reach its other side. Divergent rays, /. e., those coming from a near object (such as 0, Fig. 4), do not meet at the principal focus of the lens, but at a point (F') beyond it. This latter point is further from the lens the nearer is to the principal focus, F, until, when reaches F, F' becomes infinitely distant, and then the rays, after passing through the lens, are parallel. In like manner, Fig. 5. rays from F' would focus at 0, and hence these two points are termed Conjugate Foci. If the point ( 0, Fig. 5) from which the rays come be nearer 4 DISEASES OF THE EYE. the lens than its principal focus (F), they will not be made convergent or even parallel by the lens, but will remain divergent, although not so much so as before their entrance into the lens. If we imagine those still divergent rays to be pro- longed backward, they would meet at F, which would be called the Virtual Focus.* and Fare also conjugate foci, and hence Fig. 6. rays converging toward F from the other side of the lens will be united by the lens at 0. A Concave Lens (Z, Fig. 6) makes parallel rays of light (a b c d e) divergent on passing through it; and if the direction of the divergent rays be prolonged backward, they meet at a Fig. 7. focus (jP), which is therefore virtual, although it is the principal *It is called " virtual," because there is no real convergence of the rays at that point ; but to an observer placed on the other side of the lens (i), into whose eyes the rays fall, they would seem to come from that point. SOME ELEMENTARY OPTICS. 5 focus of the lens. In the case of concave lenses, then, there are only virtual foci. When we speak of the imacje formed by a lens, we mean the collection of foci produced by it, of pencils of rays coming from the various points of an object. For example : '\i B (Fig. 7) be the object, and a pencil of rays pass from its upper end, 0, through the convex lens, L, they will be united again at O on the secondary axis, 0' , and will form there an image of the point from which they come ; while the rays from B will form an image of that point at B' on the secondary axis, B B' . Similarly, images of all the points between and B are formed Fig. 8. between O and B' . Hence, the real images* formed by convex lenses are inverted. But if the object be at the principal focus of the lens (at F, Fig. 3), the rays on emerging at the opposite side are made par- allel, and the image is formed at an infinite distance. If the object be nearer the lens (at 0, Fig. 5) than the prin- cipal focus (i^), the image will be an erect enlarged virtual one (at V) on the same side as the object. With concave lenses the images are virtual and smaller than the object. In Fig. 8 the large arrow is the object, and F the principal focus of the lens. Rays passing through the lens from *They are called " real " images because they have a real existence, and can, in fact, be caught upon a screen. DISEASES OF THE EYE. the large arrow are made more divergent, and the image seems to be at a point (d e) found by prolongation backward of the direction of those rays after refraction. It will be convenient for the reader that I should here describe the method in use for — The Numbering of the Trial-Lenses. — The lenses in trial-cases and in spectacles are numbered according to the metrical system. The lens of one metre (39* inches) focal length is called the Dioptric Unit, or the Dioptry (1 D), of the metrical system. 2 D, 3 D, 4 D, etc., indicate the number of metre lenses, or diop- trics, contained in each of these lenses. 2 D is therefore twice as powerful a lens (its focal length only half as long) as 1 D. Convex lenses are indicated by the -}- sign placed before their number, thus, -f 5 D ; and concave lenses by the — sign, thus, — 5 D. If it be required to ascertain the focal length of a given lens, divide 100 (1 metre = 100 centimetres) by the number of the lens, and the answer will give the focal length in centimetres. For example, the focal length of 10 D is \y- = 10 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., 3D. Reflection. — When a ray of light meets a polished surface, it rebounds from it, or is " re- flected " by it, changing its direction, and the phe- nomenon is termed Reflec- tion. The images formed in plane mirrors are upright and virtual. If B (Fig. 9) be the object, rays pass from it to the mirror, 31, and are reflected. Some of the reflected rays reach the eye of the observer, and there seems to him to be an upright image of then -V>/ Fig. 9. NORMAL REFRACTION AND ACCOMMODATION. 7 B formed at O B behind the mirror in a prolongation of the reflected rays. The images formed by concave spherical mirrors are inverted and real, provided the object be beyond the principal focus of the mirror.* For example, \i B (Fig. 10) be the object, and M the mirror, the rays A and C, coming from 0, will be reflected so as to meet at 0', and the rays B E and B D, coming Fig. 10. from B, will be reflected to B', and thus form a real inverted image, B' 0', in front of the mirror. NORMAL REFRACTION AND ACCOMMODATION. The eye is a dark chamber, containing a series of convex re- fracting surfaces, namely, the cornea and the anterior and posterior surfaces of the crystalline lens ; and certain " intra- ocular media," namely, the aqueous humor, the substance of ^As this is always the case in practical ophthalmoscopy — the source of light being always beyond the focus of the ophthalmoscopic mirror — it is the only condition considered here. 8 DISEASES OF THE EYE. the crystalline lens, and the vitreous humor. 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. The refracting media are centred on the optical axis (0 A, Fig. 11), a line which, passing through the optical centre (N) of the eye, meets the retina at a point (^) slightly to the inner side of the macula lutea (J/). In treating of the eye we have to consider two sets of visual objects, viz., distant objects and near objects. Distant objects are those at 6 metres and more from the eye ; near objects are those closer to the eye than 6 metres. For practical purposes, Fig. 11. the rays which pass through the pupil, coming from any given point of a distant object, are as good as parallel, their divergence being so very slight w^hen they reach the eye, and we regard them as being parallel. Refraction. — By the Refraction of the Eye is meant the faculty it has ivhen at rest (i.e., without an effort of accommoda- tion) of altering the direction of rays of light which pass into it, making parallel rays convergent, and divergent rays less divergent. In Normal Refraction, or Emmetropia (k'/irisTpo-: an^>), as it is termed, parallel rays (see Fig. 12, in which the object from which the rays come is supposed to be 6 metres or more from the eye) in passing through the dioptric media are given such a convergence that they are brought to a focus on the layer of NORMAL REFRACTION AND ACCOMMODATION. 9 rods and cones of the retina, and form there a distinct inverted image of the point or object from which they come. In other words, the retina is placed at the principal focus of the dioptric system of the eye, which is thus adapted for parallel rays, and its " far point " (vide infra) is at infinity. Fig. 12. Accommodation. — But the eye can see near objects distinctly as well as distant objects, although the rays from any given point (a, Fig. 13) 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 refraction, but would converge toward a Fig. 13. point ( their conjugate focus a') behind the retina, and would not form a distinct image on the latter, but merely a blurred image or circle of diffusion (at 5 c). It is obvious, therefore, that an increase of refracting power in the eye is necessary, in order that near objects may be distinctly seen. It is this increase in 10 DISEASES OF THE EYE. the refracting power for the purpose of near vision which is called Accommodation. The Mechanism of Accommodation is as follows : — The ciliary muscle (771, Fig. 14) contracts, thus drawing forward the choroid and ciliary processes, and relaxing the zonula of Zinn (2), which is attached to the latter. The lens (0, 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 Fig. 14. c, cornea ; a, anterior chamber; I, lens; v, vitreous humor: i, iris; z, zonula of Zinn; m, ciliary muscle. fossa, but the anterior surface becomes more convex, thus increas- ing its refracting power. Associated with the act of accommoda- tion is a contraction of the pupil. The accompanying figure (Fig. 14) represents the changes which take place in accommodation, the dotted lines indicating the latter state. The Far Point, and the Near Point.— It is possible for the eye to see objects accurately at every distance, from its Far Point, i. e., its most distant point of distinct vision (Functum Remotum, — R.), up to a point only a few centimetres from the eye, called the Near Point (Punctum Proximum, — P.). AYe can find the NORMAL REFRACTION AND ACCOMMODATION. 11 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 distinclly, 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 dis- tance. The Amplitude 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 up to its near point. The amplitude of accommodation (a), therefore, is equal Fig. 15. to the difference in the refracting power of the eye at rest (r) and when its accommodation is exerted to the utmost (p), as expressed by the formula a = p — 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 near- est point of distinct vision a direction as if they came from the far point. The number of this lens expresses the amplitude of accommodation in a given eye. For example: — if, in an emmetropic eye (^E, Fig. 15), the near point be situated at 20 cm., then a convex lens (X) 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 (i. e., would make them parallel) as though they came 12 DISEASES OF THE EYE. from a distant object, 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 equa- tion, we find in this case — since a focal length of 20 cm. repre- sents a lens of 5 D — that a = 5 — r, but R being situated at in- finity, we designate it by the sign qo ; hence, r = ~^ = — = ; therefore a = 5 — = 5 D* ^ ^ The amount of amplitude of accommodation (/. 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 em- metropia alone is a = p as above, because in it alone is r = 0. Under the head of "Anomalies of Accommodation," Chapter II, will be found Professor Bonder's diagram representing the amplitude of accommodation at difl^erent ages. Connection between Accommodation and Convergence (Rela- tive Accommodation). — With every degree of convergence of the visual lines a certain effort of accommodation is associated. t Thus, if the object be situated 2 metres from the eye, the visual lines converge to that point, and a certain effort of accommoda- tion 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 * 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 accommodation or by a lens, in order to adapt it for the distance R. Hence, it is evident that r == ^ , because the strength, or refractive power,of a lens is inversely as its focal length, e. g., a lens of the strength of 4 D will Im. 100 cm. haveafocallength of | that of a lens of 1 D, i.e., ^7— = — r — = 0.25 cm. (see above, numbering of Trial-Lenses). Similarly, j9= p~ and a ==. ; P representing the distance of the Near Point, and A the focal length of the lens which represents the Accommodation. t A common centre in the brain governs these motions and contraction of the pupil. NORMAL REFRACTION AND ACCOMMODATION. 13 Fig. 16. increased is shown by the experiment of placing a weak con- cave glass before the eye, when it will be found that the object is still distinctly seen. And if a weak convex glass be then 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 accommodation 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 Ampli- tude of Accommodation. 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 represented 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 accom- modation is maintained, as is shown by the experiment of placing a weak prism with its base inward 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 outward, 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 main- tained, although the angle of convergence of the visual axis is less than before. The Metre Angle. If the visual Hne (^1, Fig. 16) of an eye E have to be brought to bear on a point (1, Fig. 16) 1 metre distant from it in the median line (i/"l), the angle of convergence {E\ M) which the visual line thus makes with 14 DISEASES OF THE EYE. the median line is called the Metre Angle. It expresses the degree of convergence necessary for binocular vision at that distance, and is em- ployed as the unit for expressing other degrees of convergence. If, for example, an object be situated ^ a metre (^, Fig. 16) from the eye, the angle of convergence {E 'hM) must be practically twice as large as at 1 metre : C. (Convergence) —2 metre angles. If the object be only f 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 be only one-half as great as at 1 metre, and here C. = ^ metre angle ; while if the eye be directed toward a distant object [D), there will be no angle of convergence, and if the visual lines be divergent the metre angle will be negative. YiG. 17. Now, the average normal emmetropic eye requires, for each distance of binoc- ular 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 dioptry is required, and also 1 metre angle of convergence ; at | metre from the eye 3 D of accommodation and 3 metre angles, and so on ; while for dis- tant objects neither angle of conver- gence nor effort of accommodation is required. The Angle Gamma. The Optic Axis is an imaginary line {P^ P, Fig. 17) which passes through the centre (C) of the cornea and the posterior pole (P) of the globe, i. e., a point situated between the macula lutea (M) and the optic papilla (Z>). 2'he Visual Line {MO) unites the point of fixation (0) — the object looked at — with the macula lutea. It does not coin- cide with the optic axis, but crosses it at the principal optic centre {K) of the eye. The Line of Fixation {R 0) joins the centre of rotation {R) of the eye with the point of fixation. The Angle y is the angle R P^ formed at the centre of rotation by the optic axis and the line of fixation. THE SENSE OF SIGHT. 15 The line of fixation and the visual line so nearly coincide that in practice we regard them as identical ; and hence, in practice the angle 7 is the angle K P\ It should not be confounded, as is often the case, with The Angle Alpha, which is the angle K C^ formed at the nodal point by the visual line and the major axis (C^ K) of the corneal ellipse. This axis rarely passes through the centre of the cornea ; but as it never lies far from the latter, the difference in dimension between the two angles is very slight. In order to measure the angle y, the eye is placed at the perimeter as for an examination of its field of vision. By means of the corneal reflection of a candle-flame, which latter is moved along the arc of the perimeter, the centre of the cornea is found. The position of the flame at the perimeter then gives the angle 7. The average size of the angle } is 5°. THE SENSE OF SIGHT. The Sense of Sight consists of three Visual Perceptions or Sub- Senses ; namely, the Light-Sense, the Color-Sense, and the Form- Sense. (See Chap. XYII.) The Light-Sense is the power the retina, or the visual centre, has of perceiving gradations in the intensity of illumination. The most convenient clinical method of testing the light-sense seems to be the photometer* invented by Messrs. Izard and Chibret. On looking through this instrument toward 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 diflference in illumination between the two discs within 5°, its light-sense is abnormal ; or we may say its L. D. (Light Dif- ference) 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°. In practical ophthalmology the light-sense is not yet of much interest ; but it is stated that diseases primarily involving the nervous elements in the optic nerve show a tendency to defective * To be had of Roulot, Paris. 16 UISEASES OF THE EYE. L. D. ; while diseases primarily involving the choroid and retina cause defective L. M."^ The Color-Sense is the power the eye has of distinguishing light of different wave-lengths. According to the Young-Helm- holtz theory the retina possesses three sets of color-perceiving elements, those for Red, Green, and Blue or Violet. These are termed primary colors, all other colors being compounds of them. According to Bering's theory the color-sense and the light- sense depend upon chemical changes in the retina, or in the " visual substances " situated 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 " Dis- similation," and restoration or " Assimilation," of which sub- stances the sensations of light and color are produced. In the case of the white-black substance the sensation of white, or of light, corresponds to the process of dissimilation ; while the sen- sation of black, or of darkness, corresponds to the process of assimilation. For the red-green and blue-yellow substances it cannot be said which color-sensation implies assimilation, and which dissimilation. The members of the black-white pair can mingle with each other and with those of the other tw^o pairs; but the respective members of the two color pairs (being " con- trast colors "), e. g. blue and yellow, cannot unite with each other. In testing the color-sense the spectral colors are the best for exact experiments, but the difficulty of producing them at every moment, and of combining them, renders them of little clinical use. * The Light-Sense and the Adaptation of the Retina, although related functions, must not be confounded one with the other. By the latter is meant the power the retina has of gradually adapting itself to see when the individual passes from a bright into a dim light. When it cannot do this with normal rapidity, or to a normal degree, the symptom called night-blindness results. It is quite possible for the light-sense to be normal, and yet for the retinal adaptation to be very defective, and vice versa. THE SENSE OF SIGHT. 17 The clinical method commonly employed for testing the color- sense is that of Professor Holmgren, of Upsala, which is based upon the Young-Helmholtz theory. The test-objects used are colored wools, of which a large number of skeins of every hue are thrown together. Test I (vide inside of end cover) consists in presenting to the individual, in good diffused daylight, a pale but pure green sample, and requiring him to select out of the bundle of wools of all colors before him all of those samples which seem to him to correspond to the test sample. If he do this correctly, it is unnecessary to proceed further; the individual has normal color- sense. Among the skeins, however, there are some which are termed colors of confusion (grays, buffs, straw-color, etc.) ; and if he select one, or several, of these, he is color-blind. If, now, we want to ascertain the kind and degree of his defect, we proceed to Test Ha. A pink (mixture of blue and red) skein is given to be matched. If this be correctly done, we term the person incompletely color-blind. But if blue and violet, or one of them, be selected, he is red- blind (sees only the blue in the mixture of blue and red). If he select green or gray, or one of them, he is green-blind. In order to corroborate the investigation we may employ Test lib. A vivid red skein is given. The red-blind chooses, besides red, green and brown shades darker than the red ; while the green-blind chooses green and brown shades lighter than the red. But I believe myself, and I think it is now very generally recognized, that red-blindness and green-blindness invariably go together. In violet (or blue) blindness, purple, red, and orange will be confused in Test Ha, but this is an ex- tremely rare variety of color-blindness. Total color-blindness will be recognized by a confusion of all shades having the same intensity of light, and is also rare. It is impossible by this test for any color blind person to escape detection. The individual tested should not be allowed to name the colors, but merely to match them, as above described. The reason for this is twofold. First, because, although the congeni- 2 18 DISEASES OF THE EYE. tally color-blind person is usually unaware of his defect, yet ex- perience has taught him which of his sensations are called blue, red, etc., by other people ; and hence he can often apply the right names to colors which he really does not see as such. He is assisted in this by whatever of color-sight is left to him, and by the brightness and saturation of the different colors, but is liable to frequent mistakes. Again, when the color-blind per- son does happen to know of his defect, he is often desirous of concealing it, either because he is ashamed of it, or from inter- ested motives.* A certain proportion of people (3.5 per cent, of men and less than 1 per cent, of w^omen) are congenitally color-blind, in greater or less degree, without any diminution in the other visual functions. Acquired color-blindness is found in toxic amblyopia and in atrophy of the optic nerve. The Form-Sense (Acuteness of Vision) is the faculty the eye possesses of perceiving the shape or form of objects, and, in clinical ophthalmology, the testing of this function is an import- ant and ever-recurring duty. In order that an eye may have good sight it is necessary not only that its optic nerve, retina, choroid, and refracting media be healthy, but also that its refraction and accommodation be nor- mal. 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, w^e may in general conclude that the eye is organically sound, and that the patient's com- plaints are due to the defect in accommodation or refraction. If the glasses do not restore perfect vision, we must then, by the ophthalmoscope and other methods, decide the nature of the defect. * More detailed information on color-blindness and Holmgren's test will be found in Appendix I, THE SENSE OF SIGHT. 19 By Acuteness of Vision (V.) is meant the power which an eye, or rather its macula lutea, has of distinguishing form, any anomaly of its refraction, if such exist, having been first cor- rected, i. e., while the patient wears the correcting glasses. 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 dis- tinguished. We cannot measure this image 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'. Fig. 18. In order practically to ascertain the 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 of 5' at the eye. The largest type should be seen at 60 metres (Fig. 18) by the normal eye, and the types range from this down to a size visible not further 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 distinguishable, 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 20 DISEASES OF THE EYE. metres the eye see only D = 60, which should be seen at 60 metres, then V = g^, or very imperfect vision. Should the patient's sight be so bad that he is unable to read any of the letters, it may be tested by trying 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 illumina- tion 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 any pressure would dim its vision when its turn for examination may come. In advanced age the acuteuess of vision is often reduced, 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, when one eye is closed, objects can be seen by its fellow, the gaze of the latter being fixed the while on some one object or point. Thus if, standing 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. If the fixation object be nearer to us, our field of vision will be proportionately diminished in extent. 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 eccen- tric, or indirect, vision. Eccentric vision is of great importance for the guiding of ourselves and avoiding obstacles in our way. Its use may be realized by the experiment of looking through a THE FIELD OF VISION. 21 long small-bore cylinder {e. g.j a roll of music) with one eye, thus cutting off its eccentric field, while the other eye is closed. The Dimensions of the Field of Vision may be measured by means of an instrument called the perimeter. This is a semi- circular metal band, which revolves upon its middle point, being Fig. 19. Chart of F. V. of Right Eye. in this way capable of describing a hemisphere in space. The arc is divided into degrees marked on it, from 0° placed 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 centre of the 22 DISEASES OF THE EYE. semicircle. A small square bit of white paper, the test object, is slowly moved along the inner surface of the arc from the periphery toward the centre, until it comes into view. The horizontal, vertical, and two intermediate meridians, at the least, should be examined by placing the arc of the perimeter in the corresponding planes. The boundary of the field may be noted on a diagram or chart (Fig. 19), which represents the projection of a sphere on a plane surface. Fig. 20. The radii represent different meridians, which may be deter- mined by a dial with pointer on the back of the perimeter, while the concentric circles correspond with the degrees marked on the perimeter. A pencil mark is placed on the chart at the spot corresponding to 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. The normal F.V. is not circular, but extends outward about THE FIELD OF VISION. 23 95°, upward about 53°, inward about 47°, and downward about 65°, as represented by the strong curve in Fig. 19. The limitation upward and inward is chiefly 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 Chart of F. V. of Left Eye. {LandoU.) practiced in seeing than are the upper and inner parts, and their functions consequently less developed. The acuteness of vision diminishes progressively toward 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 24 DISEASES OP THE EYE. the further toward the periphery the larger must be the test objects. Fig. 20 serves to illustrate the projection of the field of vision 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 to this extent of field, and it shows that the sensitive portion of the retina, or rather perhaps the portion of the retina which is most used, extends further 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, situated about 15° to the outer side of the point of fixation, and just below the horizontal meridian. It is shown as a white spot in Fig. 21. It is due to the optic papilla, for at that place the outer layers of the retina are wanting, and hence there is there no power of perception. There are also, occasionally, minute blind spots in the field due to the retinal vessels, which interfere with the formation of the image upon the layer of rods and cones. The Perception of Colors in the Perijjhery of the Field can be examined with the perimeter, by means of bits of colored paper 4 mm. square. It has been in this way ascertained that the boundaries of the power of eccentric perception for the different colors do not seem to correspond with the boundary for white light, nor do the boundaries of the different colors coincide. Examining from the periphery toward the centre by ordinary daylight, blue is the color 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. 21. Although the respective colors 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 color is recognizable up to the outer limit of the F.V. if sufficiently illuminated ; so that there is, in fact, no absolute color-blindness in these parts of the retina, but merely a diminished sensitiveness to colored light. CHAPTER II. ABNORMAL REFRACTION AND ACCOMMODATION. I have explained what is meant by Normal Refraction, or Emmetropia (s'a-.ac-oov, the standard; w^, eye). We recognize three different forms of Abnormal Refraction, or Ametropia (a, priv.; txhpo'j, standard; axj.'). 1. Hypermetropia {o-sp, over; iii-pov, standard; w^), in which the principal focus of parallel rays of light lies behind the retina. 2. Myopia Qiozi-^, to dose; (^4'), or Short-sight, in which the principal focus of such rays lies in front of the retina. 3. Astigmatism (a, priv, ; ari-pia, a point), in which the refraction of the eye in its different meri- dians is different. Hypermetropia. In a large proportion of cases, this form of Ametropia is due to the eyeball being too short in its antero-posterior axis (Axial H). It may also depend upon deficient refracting power in the dioptric media (Curvature H). Fig. 22. Parallel rays of light falling into the hypermetropic eye {E, Fig. 22) do not meet on the retina, but converge toward a 3 25 26 DISEASES OF THE EYE. point (c) situated behind it. Consequently, these rays do not form on the retina a distinct image of the object looked at, but produce there a " circle of diffusion " (d e), or blurred represen- tation of the object. Since, therefore, in hypermetropia the retina is in front of the principal focus of the dioptric system, rays passing out of the Fig. 23. eye from any point (i?. Fig. 23) on this retina will pass out as divergent rays, and will appear to come from a point (i?') situ- ated behind the eye, which point is the virtual conjugate focus of the point R (compare Fig. 5). Now, in order to correct the hypermetropia — that is, to render Fig. 24. the eye emmetropic, so that parallel rays passing into it may be brought to a focus on the retina — a convex lens (X, Fig. 24) must be placed in front of the eye, of sufficient strength to render the parallel rays, before they enter the eye, convergent toward R\ so that when they meet the eye they may be brought to a HYPERMETROPIA. 27 focus on the retina R, which is the conjugate focus of R'. The higher the hypermetropia, i.e., the shorter the antero-posterior axis of the eyeball, the stronger must the correcting glass be. It may be found that, with a lens of some dioptrics less power, the eye will see equally well ; but this it does by means of an effort of accommodation which supplements the inadequate refracting power of the lens placed before it. As we proceed to higher lenses, the effort of accommodation is relaxed, until, finally, the strongest lens with which vision is still at its best is reached, when, it may for the present be assumed, no further effort of accommodation is made, and L represents the whole error of re- fraction. In low degrees of hypermetropia the eye can frequently see distant objects distinctly by an effort of accommodation, which completely takes the place of L. When such an eye is found to have full vision without a glass, a beginner might 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 find that the acuteness of vision — the effort of accommodation being now relaxed — remains as good as without the glass, he will avoid the mistake. If a glass a single number higher than the exact measure of the defect be placed before the eye, vision again becomes indis- tinct, 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 stronger convex glass ivith ivhich a hypermetropic eye can see distajit objects (the test-types) most 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 by this method, unless the accommo- dation has been previously paralyzed by atropine. This method of determining the refraction by means of the trial-lenses and test-types is not relied on nowadays by ophthal- mic surgeons to the same extent as formerly, the examination of the upright ophthalmoscopic image, or else retinoscopy, having 28 DISEASES OF THE EYE. largely taken its place. In conjunction with these it is a valu- able method. The degree of the hypermetropia is indicated, as has been said, by the number of the lens which corrects it. Thus, if the number of the glass, L (Fig. 24), required to correct the hyper- metropia of the eye, E, be 2.0 D, we say this eye is hyperme- tropic two dioptrics, or has a hypermetropia of two dioptrics (H = 2.0 D). Amplitude of Accominodatioii in Hypermetropia. — 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 power required to adapt the eye to infinity ; therefore — a ^= p — ( — r) ^=p -\- r. For example : if the punctum proximum of a hypermetropic eye of 5 D be at 30 cm., what is the amplitude of accommodation? 5 D (= r) is necessary in order to make the eye emmetropic, and to accom- modate the emmetropic eye to 30 cm. 3.25 D (Vr- ~ 3-25) is required. Hence a = 3.25 + 5 = 8.25 D. The Angle y in Hypermetropia. — In hypermetropia, as in emme- tropia, the cornea is cut to the inside of its axis by the visual line ; but in hypermetropia the angle Fig. 25. which the visual line forms with the axis of the cornea is very much greater, owing to the shortness of the eyeball, and the efi'ect is to in- crease the distance be- tween the macula lutea (M) and the optic axis (A) (Fig. 25). Conse- quently, in extreme cases, when the visual lines of a hypermetropic individual are directed to an object, the axes of the cornea3 may seem to diverge, and thus the appearance of a divergent strabismus will be given. The evil effects of the constant and excessive demand upon the accommodation in hypermetropia are chiefly these : — 1. Cramp of the Ciliary Muscle. — Its persistently maintained HYPERMETROPIA. 29 contraction frequently gives rise to a tonic cramp of the muscle. This spasm is not, or may be only partially, relaxed when the correcting convex glass is held before the eye; and, conse- quently, 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 is called manifest (Hm). The entire hypermetro- pia is made up of the latent and manifest H (H = Hm -\- HI). If the cramp be excessive, parallel rays may be kept conver- gent on the retina by it alone, and vision then would be made worse, rather than better, by even a weak convex glass held be- fore the eye, a circumstance which might lead the surgeon to think he had to do with an emmetropic eye. In this case we 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 appar- ently myopic, the vision being capable of improvement by con- cave glasses. Serious errors might therefore arise if this cramp were overlooked, as it is very apt to be in the examination with the trial-lenses. When it is present in a high degree, the patient cannot maintain a sustained view of an object at any distance without suffering pain in and about the eyes. It is frequently the reason why perfect acuteness of vision is not obtained by aid of the trial-lenses, and the surgeon must be careful not to be led into an error of diagnosis by it. Exami- nation with the ophthalmoscope, or paralysis of accommodation with atropine, will enable him to avoid mistakes. In order to relieve this cramp, the ciliary muscle must be paralyzed by a solution of atropine freely instilled ; and it will often be necessary to keep the accommodation paralyzed 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. 30 DISEASES OF THE EYE. 2. Accommodative Asthenopia. — In looking at distant objects the accommodation of the normal eye is at perfect rest, and does not come into play until the object is approached close (within 6 m.) to the eye. But even for distant objects the hypermetropic eye must accommodate ; and, having for those distances used up part of its accommodative energy, it has for near objects actually less at disposition than the normal eye. Hence we find that hypermetropic people often complain of inability to sustain ac- commodative efforts for near objects for any length of time. After reading, sewing, etc., for a short time, sensations of pressure in the eyes and of weight above and around them come on, and the words or stitches become indistinct, and cannot be distinguished. The work must then be interrupted, and after a few minutes' rest 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 perform the ex- cessive demands made upon it. Accommodative Asthenopia {a,priv.; aOhoq^ strength; w^'O? as this group of symptoms is called, often appears suddenly during or after illness. The explanation of this is that although hyper- metropia 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. To relieve accom- modative asthenopia, we have merely to prescribe those lenses for near work which correct the hypermetropia, and by this means to place the eyes in the position of emmetropic eyes. 3. Internal, or Convergent, Concomitant Strabismus. — This condition has a certain relation to hypermetropia. It will be treated of in the chapter on the Motions of the Eyeballs and their Derangements (Chap. XXI). The Prescribing of Spectacles in Hypermetropia. — If a per- son be found to be hypermetropic, but his acuteness of vision without glasses be good, or as good as he desires, and he com- plain of no asthenopic symptoms, glasses need not, indeed should not, be prescribed for him. No disease in his eye will result MYOPIA. 31 from his going without glasses. At the most he may get cramp of accommodation. If the patient complain of imperfect distant vision due to hypermetropia, then those lenses which correct the Hm may be prescribed for distant vision, to be worn either constantly or occasionally, 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 perfectly satisfied with their distant vision. For relief of the asthenopia 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. Fig. 26. If there be excessive cramp of accommodation, glasses to cor- rect the whole hypermetropia should be worn while the eye is under atropine ; and afterward as much of the HI as possible, along with the Hm, should be corrected by glasses to be worn constantly. Myopia, or Short-sight. This form of ametropia is due, in a vast majority of cases, to the an tero- posterior axis of the eyeball being too long (Axial M.), and hence, its refracting media not being proportionately diminished in power, parallel rays of light (a h, Fig. 26) are not brought to a focus on the retina, but in front of it (at/), and form on the retina circles of diffusion (c d). Myopia may also be caused by abnormally high refracting 32 DISEASES OF THE EYE. power ill the crystalline lens, as in spasm of the ciliary muscle, and in some cases of commencing cataract, and also by conical cornea. (Curvature M.) Since, in the myopic eye, the retina is beyond the principal focus of the dioptric system, rays emerging from any point (c. Fig. 27) of the fundus will pass out convergently, and will unite in front of the eye at the conjugate focus of the retina (r). (Compare Fig. 4.) Conversely, rays diverging from a certain point (r) in front of the eye will be focused on the retina (c). If an object be brought toward the eye, the divergence of Fig. 27. those rays which pass from it into the eye increases, until, when it has reached the point r, their divergence is just sufficient to allow them to be united at the conjugate focus c, which is on the retina. This point r is the punctum remotum-^^ of the myopic eye. In order, therefore, that the short-sighted eye may be able to see distant objects, it is necessary that the parallel rays * The punctum remotum is always the conjugate focus of the retina. In an emmetropic eye it is at infinity, since the retina is at the principal focus of the eye, and the rays pass out parallel. In hypermetropia it is behind the eye, and is virtual or negative, because the retina is in front of the principal focus, and the rays pass out divergently, as if coming from a point behind the retina. Lastly, in myopia it is situated at a finite distance in front of the eye, and is real and positive, because the retina is beyond the principal focus, and the rays emerge convergently. MYOPIA. 33 coming from those objects should be given such a degree of diver- gence before they pass into the eye as though they came from this punctum remotum. This can readily be effected by placing the suitable concave lens in front of the eye, and the number of this glass will indicate the degree of the myopia, i.e., by how many dioptrics the refracting power of the eye is in excess of that of an emmetropic eye. The focal length of the correcting glass corresponds, of course, with the distance of the punctum remotum from the eye, provided the glass be held close to the cornea. 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 Fig. 28. came from this point, and will form an exact image of the object from which they come on the retina. For example : if the punctum remotum (Fig. 28) be situated at 14 cm. from the eye, then the number of the correcting lens will be 7 D, because the focal distance of this lens is 14 cm. ('T'T = '^)- ^^ practice, however, we cannot hold the glass so close to the cornea, and, therefore, we must subtract the distance between it and the cornea from the focal distance of the required lens. In the above case, suppose the distance from cornea to glass be 4 cm., the required lens will be 10 D (-\2^ = 10). Determination of the Degree of Myopia. — The degree, or amount, of myopia, as of hypermetropia, may be determined either by the ophthalmoscope, or experimentally, by means of the trial-lenses and test-types. 34 DISEASES OF THE EYE. By the latter method, examining each eye separately, we find the correcting glass by placing our patient as directed in the section on Acuteness of Vision. A weak concave trial-glass is then held before the eye under examination, and higher numbers are gradually proceeded to, until the glass is reached which gives the eye the best distinguishing power for the types. 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 class is used the eye may still see well, but it does so only by an effort of accommodation, and the glass employed represents not merely the myopia present, but also this accommodative effort. No more serious mistake can be made Fig. 29. than the prescribing of too strong concave glasses for a myopic individual, as will be seen further on. The Amplitude of Accommodation in Myopia. — The myopic eye has an excess of refractive power as compared with the emmetropic eye ; therefore, in calculating its amplitude of accommodation, this excess must be subtracted from the positive refractive power ( p) which would be required to adapt the emmetropic eye to the same punctum proximum ; or, in other words, the myopic eye has need of less accommodative power than the emmetropic eye, because, even at rest, it is adapted for a dis- tance (R., its punctum remotum) for which the emmetropic eye has to accommodate ; hence, in myopia — a = p — r. For example, a myopic person of 10 D who can accommodate up to 8 cm. {p = W = 12 D) has an amplitude of accommodation of 12 — 10 = 2 D. The Angle y in Myopia. — In myopia, owing to the length of the jvnropiA. 35 eyeball, the cornea is cut much closer to its centre by the visual line than in emmetropia ; or, these two lines may coincide ; or, the cornea may even be cut to the inside of its centre by the visual line {vide Fig. 29). In any of these cases, but especially in the latter, the effect will be that of an apparent convergent strabismus. Myopia is rarely, or never, congenital. It generally first shows itself from the eighth to the tenth year, and is apt to increase, especially during the early years of puberty. Its progressive increase is encouraged by use of the eye for near work, such as reading, sewing, drawing, etc., and is due to a further elongation of the antero-posterior optic axis. But it is certain that, in addition to this exciting cause, there must be some predisposing condition, or conditions, as only a few children become short-sighted, although they are all educated in a very similar manner, so far as the use of their eyes is concerned. Stilling"^ and Seggel f have found that a low orbit is usually associated with a myopic formation of eyeball, and they are inclined to regard these largely in the light of cause and effect. For with a low orbit, and when, as often happens, the tendon of the superior oblique has an almost transverse direction, the combined pressure of the two obliques upon the plane of the equator during the period of growth would tend to cause elongation of the anterior-posterior diameter of the eyeball. Certain it is that myopia is often hereditary and seen in several members of a family. The whole question of the predisposing causes of myopia must still be regarded as subjudice. In cases of commencing cataract a slight degree of myopia may sometimes be noticed to come on. This is due to a higher refracting power in the lens as the result of the changes begin- ning in it. HirschbergJ states that late myopia coming on without cata- * Trans. Interhat. Ophth. Congress, 1888, p. 97. t Von Grcefe^s Archie, xxxvi, II, p. 1. X Deutsche Med. Wochenschr., 1891, No. 13. 36 DISEASES OF THE EYE. ract from the fortieth to the sixtieth year is a very certain sign of diabetes. He offers no explanation of its occurrence in this way. I have not myself seen such a case. Many short-sighted people half close their eyes when endea- voring to distinguish distant objects, in order that the rays may be prevented, so far as possible, from passing through peripheral parts of the crystalline lens, which would increase the circles of diffusion. This habit it is which has given the name of myopia to the condition. Progressive Myopia frequently becomes complicated with Organic Disease, viz: — 1. Posterior Staphyloma. — This condition is recognized by the ophthalmoscope as a white crescent at the outer side of the optic papilla. Owing to bulging of the eye- ball, the choroid becomes atrophied at this place, and admits of the white sclerotic being seen. The staphyloma sometimes extends all round the optic papilla ; and, by stretching of the retina in these extreme cases, its functions may become de- ranged, and, in consequence, the blind spot increased in size. 2. Choroidal Degeneration in the Xeicjhhorhood of the Macula Lutea. — This should always be carefully looked for, as the region of the yellow spot is very liable to disease in bad cases of pro- gressive myopia. The disease seems to begin in the choroid, giving the appearance of small cracks or fissures, which later on develop into a patch of choroidal atrophy. The retina at the spot becomes disorganized, and very serious disturbance of vision is the result, the patient being disabled from reading. 3. Hemorrhage in the Retina at the Yelloiv Spot may occur, causing similar visual defects ; and, when the hemorrhage 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. 4. Detachment of the Retina. — This is a frequent and most serious complication of progressive myopia. It will be fully considered in the chapter on Diseases of the Retina (Chap. XV). MYOPIA. 37 5. Opacities in the Vitreous Humor. — These often accompany the choroidal alterations. Insufficiency of the Internal Recti Muscles is another anomaly which we find very commonly associated with progressive myopia ; but it can hardly be regarded as an organic disease, or as a result of progressive myopia. It may more properly be looked upon as a concomitant congenital irregularity, and, per- haps, as one of the causes of the progressive nature of myopia. It will be fully discussed in Chapter XVIII. Cramp of Accommodation is often present in myopic eyes, and will cause the myopia, examined with trial-lenses and test-types, to seem higher than it is. The surgeon, being aware of this source of error, will guard against it. The Management of Myopia. — The great danger of myopia being its progressive increase, with consequent or attendant organic disease, its management is one of our most important and difficult tasks, especially in these days of high-pressure education. Many cases of myopia are not progressive, and cause no anxiety ; others are periodically progressive ; and again, others are continuously or absolutely progressive. In the periodi- cally progressive form the age of puberty is usually the time of greatest increase and greatest danger, the myopia often becoming stationary later on. In the absolutely progressive cases the increase goes on rapidly until after puberty, and then more slowly, but it usually leads to considerable loss of vision unless the greatest care be taken. In the progressive forms, close approximation of the eyes to the work, meaning convergence of the visual lines and accom- modative effort, as, also, everything which tends to cause conges- tion of the eyes and head, are what we have to try to prevent. In order that these patients may not be obliged to approach close to their work, they should occupy themselves with large, and not with minute objects, and only by good light. When possible (vide infra) such spectacles should be prescribed for them as will enable them to read at a distance of 25 to 30 cm. In reading and writing, the books and papers should be on a 38 DISEASES OF THE EYE. slope, to facilitate an upright position of the head, and the table should not be too low. They should pause to rest for some minutes occasionally during the spell of work, while the number of working hours in the day should be restricted. The action of the bowels should be regulated, the feet kept warm, and all excessive bodily exertion avoided, so that congestion of the head and eyes may be prevented. Where posterior staphyloma, hemorrhages at the macula lutea, or opacities in the vitreous humor are present, Heurteloup's artifical leech applied to the temple, mild purgatives, and complete rest of the eyes, with the use of atropine for some weeks to immobilize the ciliary muscle, are to be ordered. If the choroidal changes be very marked, small doses of the perchloride of mercury are indicated. The eyes should be protected from light by blue or smoked protection- spectacles, this latter precaution being especially necessary during the use of atropine. Insufficiency of the internal recti should be corrected by prisms, or by operation. The correction of the myopia by suitable glasses is an impor- tant and difficult matter. In some cases of slight myopia (2.5 T> and less), in young patients with good amplitude of accommo- dation, the correcting glasses may be prescribed to be worn constantly for near as well as for distant objects, and thus the patient is placed in the position of an emmetrope. In other cases, where the error of refraction is not excessive, and the eye is organically healthy, the whole defect may be corrected for distant vision, if the individual be warned not to use his glasses for near work, lest he should strain his accommodation. In high degrees of myopia strong glasses may be given for distant vision, but it is wise to give them 1 D or 1.5 D less than the full cor- rection, so that all danger of accommodative effi)rt may be avoided. In these same cases, provided there be no ophthalmo- scopic changes, or only some of minor significance, and if the vision be good, such a glass may be given as will enable the patient to read at 25 to 30 cm. This glass may be found by subtracting from the number of the glass representing the degree of the myopia (say 7 D) the lens whose focal length corres- ASTIGMATISM. 39 ponds to the distance (say 30 cm.) required (this here would be 3.25 D, because Vf" = 3.25, and then 7.0 — 3.25 = 3.75 D, the glass required). By aid of such glasses this myope can read at a distance much more favorable for the convergence of his optic axes, and for the erect position of his head ; but there is a danger associated with their use — namely, that if the patient aproach his book closer than the prescribed distance, he does away w^ith the advantage he should gain from them, and, by necessitating an effort of accommodation, turns them to a serious souirce of danger for the eye. Patients in whom the acuteness of vision is much lowered are liable to approach their work in this way, in order to obtain larger retinal images, the more so as the concave glasses diminish the size of the images, and in such cases it is better not to give glasses for near work. It is often necessary to provide patients with spectacles which will enable them to use their eyes for some special purpose at a given dis- tance, e.g.^ the pianoforte, painting, etc., and these can be found as above explained. Astigmatism. This is a compound form of ametropia, due to the cornea being more curved in one meridian than in another, similarly as the back of the bowl of a spoon is more convex from side to side than from heel to point. In Regular Astigmatism the directions of the greatest and least curvations 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 fre- quently the vertical. Consequently, we say the astigmatism is " with the rule " in those cases in which the meridian of greatest curvature is the vertical ; and, where that meridian is the one of least curvature, we say the astigmatism is " against the rule." The result of this is, that a pencil of rays passing into the eye, instead of meeting at a common focus, is irregularly refracted, those rays passing through the vertical meridian of the cornea being brought to a focus much earlier than those which fall 40 DISEASES OF THE EYE. through its horizontal meridian ; and, therefore, at the focus of the former the latter rays form a horizontal streak of light. The intermediate, or oblique, meridians will probably be of regularly intermediate refracting power. The interval between the foci of the two principal meridians is called the Focal Interval, and is a measure of the astig- matism. The accompanying diagram (Fig. 30), after Bonders, will assist in the understanding of the course of a pencil of rays after they have passed through an astigmatic cornea, those rays belonging to the horizontal and vertical meridians being chiefly considered. At A neither vertical (v, v') nor horizontal {]i, h') rays have yet been united at their foci, but the vertical rays are the nearest Fig. 30. to their focus ; and, therefore, the appearance which the pencil of rays would give, if caught here on an intercepting screen, is an oval with its long axis horizontal. At B the vertical rays have met at their focus, but the horizontal rays not as yet at theirs, and the result is therefore a horizontal straight line. At C the vertical rays are diverging again from their focus, and the hori- zontal rays have still not come to theirs. At D the same condi- tions exist, only a little further on, where the one set of rays is diverging, the other still converging, but each at the same angle ; hence the shape of the figure is round. At F the hori- zontal 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. There are various kinds of regular astigmatism, according to ASTIGMATISM. 41 the position of the two principal foci with reference to the retina, as follows : — 1. Simple Hypermetropic Astigmatism. — When the focus (V, Fig. 31) of the vertical rays is situated on the retina (emmetropia in that meridian), while that CH) of the horizontal rays lies behind the retina (hypermetropia in that meridian). Fig. 31. Fig. 32. 2. Compound Hypermetropic Astigmatism. — When'the^foci of both sets of rays is behind the retina, that (H, Fig. 32) of the horizontal rays further back than that (V) of the vertical rays. 3. Simple Myopne Astigmatism. — When the focus (H, Fig. 33) of the horizontal rays is situated on the retina (emmetropia in Fig. 33. Fig. 34. that meridian), while the focus (V) of the vertical rays is situ- ated in front of the retina. 4. Compound Myopic Astigmatism. — When the foci of both sets of rays are situated in front of the retina, but further forward in the case (V, Fig. 34) of the vertical rays. 5. Mixed Astigmatism. — When the focus (H, Fig. 35) of the 4 42 DISEASES OF THE EYE. horizontal rays falls behind the retina (hypermetropia in that meridian), and the focus (V) of the vertical rays in front of the retina (myopia in that meridian). Symptoms of Astigmatism. — We may conclude that an individual is as- tigmatic if he sees horizontal (or ver- tical) lines, such as the horizontal por- tions of Roman capital letters, or the horizontal lines in music, distinctly, while the vertical (or horizontal) lines seem indistinct. We have such a complaint, for example, when the retina is situated at the focus of the parallel rays passing through the vertical meridian of the cornea. Suppose an eye to be emmetropic in the vertical meridian, and ametropic in the horizontal meridian. We must first con- sider 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, conse- quently, the point will appear distinctly defined above and below. A line may be regarded as a number of points, and, in order to understand how lines will be seen by an astigmatic eye such as the above, it is only necessary to arrange a number of points in vertical and horizontal lines — as at a and b in Fig. 36. It is evident at once from mere inspection that the horizontal line will appear distinct, because the rays which diverge from each point of the latter in a vertical plane, i.e., at right angles to the direction of the line, are brought to a Yig. 36. 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 diff'usion images resulting from them 0C» exist in the horizontal direction, and, consequently, cover or ASTIGMATISM. 43 overlap each other on the horizontal line, and therefore are not seen. At the ends of the line only (6, Fig. 37) do the diffusion images cause a " fuzziness," or make the line seem longer than it is. In this case a ^^' vertical line (a, Figs. 36 and 37) seems in- ^^ distinct ; because, the horizontal meridian ^^ being out of focus, the diffusion images ex- ^KK^m^mm^Bsm 5 isting in that direction are very apparent, ^J as they do not overlap. 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 com- plaint 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, due to constant effort to see distinctly, and we cure the headache when we correct the astigmatism. It has been stated that epilepsy, if not capable of being pro- duced by refractive errors, especially astigmatism, in persons with stable brains, may sometimes have such errors as its excit- ing cause where there is already a predisposition to the disease. But the crucial test of the correctness of this view — namely, a cure of the epilepsy by correction of the error of refraction with glasses — is still wanting. All these signs and symptoms appertain more to the rather high degrees of astigmatism. Slighter degrees may cause no annoyance beyond some indistinctness of vision ; and, indeed, slight degrees of hypermetropic astigmatism often pass un- 44 DISEASES OF THE EYE. noticed until late in life, when the accommodation begins to fail. 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 con- siderable difiference in power, even, perhaps, by convex as well as by concave glasses. The ophthalmoscope affords us an admirable means of diag- nosing 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 horizontal vessels in the retina of the eye simul- taneously, but must alter his accommodation to be able to see first the one set and then the other. A comparison of the shape of the optic papilla, as seen in the upright and in the inverted images, also gives 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, in the meridian of highest refraction, the image lies nearer the convex lens than in the meridian of lowest refraction, and, hence, is much less magnified in the former than in the latter meridian ; and here, consequently, the round optic papilla is seen as an oval with its long axis horizontal. 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, ASTIGMATISM. 45 the long axis of the oval being in the direction of the axis round which the lens is rotated. The determination of the degree of astigmatism can also be accomplished with the ophthalmoscope, and will be treated of in the next chapter. The Estimation of the Degree of Astigmatism, and its Cor- rection. — It is evident that, to correct astigmatism, the ordinary spherical lenses would be of little use, for they affect the refrac- tion of the light passing through them equally in every direc- tion. We employ, therefore, what are termed cylindrical lenses, ground in a peculiar way, which refract light in one direction only, viz., that corresponding to their curvatures and at right angles to their axes. The rays which pass through these lenses in a direction corresponding to their axes are not refracted, but pass on without deviation as they would do through a piece of plane glass. Although astigmatism is nowadays almost universally esti- mated by means of the ophthalmoscope, yet, in order to give the student a clear idea of the matter in the simplest way, I shall here describe a subjective method for its estimation, while its objective estimation by aid of the ophthalmoscope will be treated of in the next chapter. Simple Astigmatism. — If, now, a case come before us in which we suspect astigmatism, we place Snellen's Sunrise (_vide diagram at end of book), or some such diagram, at 6 metres from the eye — the other eye being excluded — and inquire of the patient whether there be any line which he sees much more distinctly than the others, and can trace further towards the central point. If that be so, we know that he is emmetropic in the meridian at right angles to that line, provided his accommoda- tion be at rest, and ametropic in the meridian corresponding to that line. In case the horizontal line below at each side be the distinct one, the eye is emmetropic in the vertical meridian, and prob- ably hypermetropic in the horizontal meridian, because the latter is generally that of least curvature. Consequently, a 46 DISEASES OF THE EYE. convex cylindrical lens, held with its curvature horizontally (axis vertical) before the eye, will correct the defect. The highest convex cylindrical glass which gives the patient the best possible distant vision will 'be the correcting glass. This is a case of Simple Hypermetropic Astigmatism (As. H.). If the lens required he -{- 2 T) Cyl. it would be As. H. 2 D ; and in prescribing for the optician we should write " -)- 2 D Cyl. Ax. Vert." If the central vertical line be the distinct one, then em- metropia exists in the horizontal meridian, and probably, there- fore, myopia in the vertical meridian ; and a concave cylindrical lens held before the eye with its curvature vertical (axis hori- zontal) will correct the defect. The lowest concave cylindrical lens, which gives the patient the best possible distant vision, will be the correcting lens. This is a case of Simple Myopic Astig- matism (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." I advise the reader to make now a few experiments for himself with cylindrical lenses, by means of which he can pro- duce artificial astigmatism in his own eye. If he hold a -f- 1-0 Cyl. before' his eye, w^ith its axis horizontal, it gives a myopia of 1.0 D to the vertical meridian of the eye, while the horizontal meridian remains emmetropic ; and, consequently, he will see the central vertical line of the diagram distinctly, while the horizontal lines will be indistinct. By placing a — 1.0 Cyl. with its axis vertical before the eye, in addition to the -f 1-0 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. Compound Astigmatism. — If no line be very distinctly seen, then we may commence our examination with Snellen's Distance Test-Types, and test in the ordinary way with spherical lenses, until we find that one which gives the best distant vision. This H. 4 D + H. 1 D ASTIGMATISM. 47 we place in a spectacle frame before the eye, and proceed, as already explained, to ascertain the mer- h. 4 d idians of greatest and least curvature of the cornea. If the spherical lens be -[- 4 D, and with it the horizontal lines in the sunrise diagram be the most distinct, then the vertical meridian is shown to be cor- rected, and the eye is probably still hypermetropic in the hori- zontal meridian, and requires a -{- cylindrical lens with its axis vertical, in addition to the spherical lens, to correct the entire defect. Suppose this cylindrical lens be found to be -[- 1 D Cyl., then the H. in the horizontal meridian will be shown to be 5 D, and the astigmatism to be 1 D. The latter noted down would be of little practical value, and therefore we prefer to write in our note-books the factors of the Astigmatism, thus : " H, 4 D + As. H. 1 D Horiz." ; or, as for the optician, " -j- 4 D Sph. O + 1 D Cyl. Ax. Vert."* This is Compound Hypermetropic Astigmatism. In an analogous way we examine for Compound Myopic As- tigmatism, in which every meridian is myopic, but the vertical more so than the others. Mixed Astigmatism. — Lastly, we come across cases in which both concave and convex spherical lenses produce a certain amount of improvement, but neither give full vision. Placing then one or other before the eye in the spectacle frame, the examination is proceeded with by aid of Snellen's sunrise. We ascertain, for example, what is the lowest concave spherical lens which will bring out one horizontal ray distinctly ; let this be — 3D; we have then myopia of 3 D in the vertical meridian. Now, having removed the — lens, we find what is the highest convex lens which will bring out one vertical line distinctly ; let it be -f 5 D; this indicates hypermetropia of that amount in the horizontal meridian. We may correct such a case in either of two ways — (a) By a Sph. — 3D, which will correct the ver- * The sign o indicates " combined with." 48 DISEASES OF THE EYE. tical meridian, but will increase the hypermetropia in the hori- j^ 3j^ zontal meridian by 3 D, making it 8 D, which can then be corrected by combining a cylindrical lens of -f 8 D, axis vertical, -H. 5D wi ith the above spherical lens, (b) By a spherical -\- 5 D, which will correct the horizontal meridian, but will increase the myopia in the vertical meridian to 8 D, necessitating the combi- nation of a — cyl. lens of that number, with the -\- 5 D Sph. For reading, writing, etc., an over-correction of the horizontal meridian with -f 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 astigma- tism accurately, that the accommodation be at rest, it is desir- able, before the examination for any of the hypermetropic forms, to instil atropine into the eye. Lental Astigmatism. — Disturbances of vision due to astigma- tism often make their appearance for the first time at middle age, or even later, and are then apt to be mistaken for ambly- opia. In such cases the cornea has been astigmatic all through, but the defect has been masked by a compensating astigmatism of the crystalline lens, produced by an unequal accommodative contraction of the ciliary muscle. When, now, as life advances, the amplitude of accommodation diminishes, the power of the ciliary muscle to produce this active compensatory lental astig- matism also diminishes, and finally disappears; and, conse- quently, the corneal astigmatism comes to the front. Or, in astigmatic individuals the astigmatism may alter in degree at this time of life. Under atropine, too, astigmatism may appear, the existence of which was not previously known. This is termed active, or dynamic, lental astigmatism. Passive, or static, lental astigmatism is due to irregularity in the shape of the unaccommodated lens, and, as the case may be, gives rise to disturbances of vision similar to those caused by corneal astigmatism ; or, it increases existing corneal astigmatism ; ANISOMETROPIA. 49 or, it more or less completely compensates the corneal astigma- tism. It has no clinical importance which does not attach to corneal astigmatism. Irregular Astigmatism. In irregular astigmatism the refraction of the eye differs, not only in different meridians of the eye, but even in different parts of one and the same meridian. This is frequently due to irregularities on the surface of the cornea, the result of former ulcers, and also sometimes to irregular refracting power in different parts of the crystalline lens. It cannot be corrected. Anisometropia means a difference in the refraction of the two eyes, one being myopic, hypermetropic, or astigmatic, while the other is emme- tropic, or ametropic in a way different from its fellow. 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 to fully 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 ame- tropic, and fully correct the least ametropic eye. Each such case must be dealt with as it permits. ANOMALIES OF ACCOMMODATION. Presbyopia. This is a diminution in the amplitude of accommodation, which commences at an early age, and is due solely to natural changes taking place slowly in the crystalline lens. It might not, therefore, strictly speaking, be considered as an anomaly. The power of accommodation commences to diminish in early 50 DISEASES OF THE EYE. childhood, the near point beginning then to recede from the eye. Bonders it was who first discovered this fact, and ascertained the laws which govern the progressive decrease of accommoda- tive power. He designed the accompanying diagram (Fig. 38), which illustrates the decrease from the tenth year of age, and indicates the amplitude of accommodation at different ages. The numbers along the upper horizontal line refer to the ages, those along the left-hand perpendicular line to the dioptrics. Fig. 38. r rr f» 9s y> _s^ o ^.r ^f^> .r.r n ef r? tt s, rv- 1 ^^ \, v \ <' X ■10 \ fi \ S \ K \ f \ jr \ N j^ N V .1 X s. ? N \ s^ N -. Y ^~-7~-Civ^ P P T*^ '^si— ? /, ./ 1 1 1 ZJ The shorter curve shows the refraction of the eye when in a state of rest. This is unchanged until the 55th 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 j) p shows the positive refracting power of the eye corresponding to the punctum proximum, and its gradual diminution as life advances ; and how, at the age of ^b, it becomes even less than the minimum refraction in former PRESBYOPIA. 61 years. The two curves meet at the age of 73, and then all power of accommodation ceases. The number of dioptrics included between the two curves on the vertical line correspond- ing to 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 accommodation 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 produc- tion 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, be- cause 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 individual is often seen to improve their brilliancy by procuring stronger light. Presbyopia is usually said to be present when the near point lies at more than 22 cm. from the eye, and we correct it by giv- ing such a convex glass for reading, etc., as will bring the near point back to 22 cm. Now, in order to see at that distance, a positive refracting power ( j?) of (-^^ =) 4.5 D is necessary ; and, if the eye have not so much positive refraction, a convex glass must be given to it of such power as will bring jj up to 4.5 D ; and this lens is the measure of the presbyopia. At the age of 40 (vide Donders' diagram. Fig. 38) the eye possesses a posi- tive refraction of just 4.5 D ; and, therefore, from this age pres- byopia {-pia^uq^^ uiili) is said to commence in emmetropic eyes. The presbyopia, then, is equal to the difference between the * An old man. 52 DISEASES OF THE EYE. positive refracting power possessed by the eye and 4.5 D, and the number thus found is the correcting glass for the pres- byopia. It is important for the patient's comfort that in prescribing glasses for presbyopia, if there be any hypermetropic astigma- tism present, it should be corrected by the suitable -|- cylinder lens added to the spherical glasses. The following table indicates the presbyopia of the emme- tropic eye : — Age. p. required. p. existing. Presbyopia. 40 4.5 4.5 45 4.5 3.5 1.0 60 4.5 2.5 2.0 55 4.5 1.5 3.0 60 4.5 0.5 4.0 65 4.5 0.25 4.25 70 4.5 -1.0 5.5 75 4.5 -1.75 6.25 80 45 -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 myopia, it may not come on at all. The hyperme- trope of 3 D would be presbyopic at the age of 27 ; because, in order to arrive at the 4.5 D of positive refraction required, he must have an amplitude of accommodation of (3 D -j- 4.5 D) 7.5 D, and this he has only up to that age {vide Fig. 38). 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 a presbyopia of 4.25; consequently, he will now require a -{- glass of only 0.25 D. Presbyopia must not be mistaken for slight paralysis of accommodation. They are distinguished by the fact that, in the former, the amplitude of accommodation corresponds to the age of the patient as given in Bonders' table. paralysis of accommodation. 53 Paralysis of Accommodation. 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 — rarely with paralysis of the external rectus. The Symptoms are similar to those of presbyopia, and give inconvenience to the patient according to the state of his refrac- tion. 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 for near objects. If he be myopic, vision is less affected than in either of the other forms of refraction ; indeed, if he be very near-sighted, being able to see near objects at his far point, he may suffer little or no inconvenience. Micropsia is a common symptom in cases of partial paralysis of accommodation, and is due to the fact that the great effort of the defective accommodation gives the sensation of the object being much nearer to the eye than it really is. Causes. — The most common cause of paralysis of accommoda- tion is the action of atropine ; 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 exposure to cold ; or it may depend upon syphilis, syphilitic periostitis at the sphe- noidal fissure, syphilitic gumma, or syphilitic inflammation of the nerve itself. In cases of double paralysis of accommodation a central cause must often be looked for. Paralysis of accommodation and mydriasis are sometimes forerunners, by many years, of serious mental derangement. Diphtheria is a frequent cause of paralysis of accommoda- tion, usually without, but sometimes with, mydriasis. The onset 54 DISEASES OF THE EYE. occurs most commonly some weeks after the throat affection, which need not have been of a severe character. Indeed, the faucial attack may haye had no apparent diphtheritic character, and may have been so slight as almost to have escaped the notice of the patient. The lesion in these cases is probably a central one, and the evidence points to miliary extravasations of blood in the floor of the third ventricle ; but there are those who hold that the paralysis is due to a poison, that it is a toxic paralysis. During the recent epidemics of influenza {la grippe) cases of paralysis of accommodation were recorded, occurring some of them during the acute stage and others during convalescence. They all recovered except one, which seems to have gone on to bulbar paralysis.* Paralysis of accommodation in middle life may be due to diabetes, and should make us suspicious of the presence of this disease. Blows on the eye are apt to cause paralysis of accommodation, usually with mydriasis. The Treatment depends, of course, upon the cause of the paralysis. The instillation of a 1% 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 potassium 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. 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 diphtheritic cases a general tonic treatment, especially * Uhthoff in Deutsche Med. Wochenschr., No. 10, 1890. SPASM OF ACCOMMODATION. 55 iron, is indicated ; and here the prognosis is invariably favor- able. Accommodative Asthenopia has been already treated of under the head of Hvpermetropia (p. 30). 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."^ Occur- ring 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. *A. V. Graefe, Archiv f. Ophthal., vol. ii, pt. 2, p. 308; Liebreich, Archiv f. Ophthal., vol. iii, pt. 1, p. 259 ; C. E. Fitzgerald, Trans. Ophthal. Soc, vol. v, p. 311. CHAPTER III. THE OPHTHALMOSCOPE. Although the dioptric media of an eye be perfectly clear and normal, yet no detail of its fundus can be discerned by the un- aided eye of an observer who looks through the pupil, the latter being for him merely a dark opening. The reason of this is, that these dioptric media are composed of a system of convex lenses. To explain : Suppose the inside of a small box (vide Fig. 39. Fig. 39) 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 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, b, 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 more accu- rately, we place a convex lens immediately within the aperture, the course of the rays is altered. All the rays passing into the 56 THE OPHTHALMOSCOPE. 57 box (Fig. 40) from L are brought to a focus on its opposite side at m by the convex lens, n; and, according to the optical law of conjugate foci, all the rays passing out from the box meet again at the source of light, X, 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 catch any of these rays ; for, if it be Fig. 40. ^1 - "t^ 7Z m placed anywhere between the aperture and L, it would cut off the light passing from h into the box. Helmholtzs Ophthalmoscope. — 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 Fig. 41. with his ophthalmoscope in the year 1851. The instrument he invented was composed of a number of small plates of glass, (Fig. 41), from which light from L was reflected into the eye E, and thus the fundus of the latter illuminated. From m rays pass back again by the same course to the ophthalmoscope, some being reflected back to L; but some, passing through the 58 DISEASES OF THE EYE. 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 cen- tral opening has been substituted. This mirror (Fig. 42) throws convergent rays into the eye E] and these, being made more convergent by the refracting media, cross in the vitreous humor, and light up part (a h) of the fundus. From every point of this illuminated 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 Fig. 42. parallel rays, passing through the ^aperture (c) of the ophthal- moscope, falljnto the observer's eye, and, if it be emmetropic, are brought to a focus on its retina ; the rays from m at m' , those from x at x\ and those from ij at y ; and thus an image of the part x m y is formed on the observer's retina. The foregoing method of examining with the ophthalmoscope is called The Direct Method, or The Examination of the Upright Image. By it the various parts of the fundus are seen in their natural positions, but much enlarged (about 15 diame- ters in the emmetropic eye) ; and it is, consequently, very valuable for examining minute details. It is necessary for this method that the surgeon should approach his eye as close as possible to the eye under examina- THE OPHTHALMOSCOPE. 59 tioD, in order to receive as much of the light coming out of it as possible. It is also necessary for this method that the accommodation both of the surgeon's and of the patient's eye 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 accommodation, the rays will, on leav- ing his eye, become convergent, instead of parallel, and, falling into the surgeon's eye, will be brought to a focus in front of his retina. If the surgeon exert his accommodation, the parallel rays from the patient's eye will likewise, on falling into his, the surgeon's, eye, be brought to a focus in front of his retina. And if both patient and surgeon accommodate, the focus of the rays from the patient's fundus oculi will, of course, lie still further in front of the surgeon's retina. The patient's accommodation will be relaxed by making him gaze at the black wall behind the sur- geon's head, or his accommodation may be paralyzed with atropine. But atropine should never be used unless absolutely necessary, owing to the inconvenience it causes the patient. Voluntary relaxation of the accommodation on the part of the surgeon is often a matter of much difficulty to beginners. The ciliary muscle, not being a voluntary muscle, is not under our direct control, and can be influenced only in a secondary way through the convergence of the optic axes ; for this con- vergence is regulated by voluntary muscles ( the internal and external recti), and is intimately associated with the effort of accommodation. With parallel optic axes our accommodation is relaxed ; therefore, when we want to relax our accommoda- tion, 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 accomplishment of this parallelism and relaxation of accommodation very difficult to many. It is not easy to teach another person how to relax his accom- modation, but the following hint may be of use. Take a printed 60 DISEASES OF THE EYE. page, and hold it at the ordinary reading distance, so that the type may be clearly seen ; then gaze vacantly at it, so that the type may become indistinct. The accommodation is now relaxed, and the act is accompanied by a peculiar sensation in the eyes. When examining in the erect image, cause this same sensation to take place ; and it may be assisted if, with the eye which is not in use, the black wall behind the patient's head be gazed at. 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 {I, Fig. 43) of about 14 D is here used. The latter is held about 10 cm. Fig. 43. from the eye {E) under examination, while the observer throws the light through it into the eye. In passing through the lens the rays are made convergent, and this convergence is increased by the refracting media, so that the rays cross in the vitreous humor, and light up a portion of the fundus 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 the lens, and are united by it at a' h'; and thus a real inverted image is formed of the part a b, which image may be seen by the ob- server whose eye is placed behind 0. The stronger the lens /, the more convergent must rays from the examined eye be made ; and, consequently, the closer must a' b' be to each other, and the smaller and brighter must be the image formed. The weaker THE OPHTHALMOSCOPE. 61 the lens I, the larger and less brilliant is the image, and the less annoying to the surgeon are the reflexes from the surfaces of the lens. 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 will then be seen in the pupil. Keeping the pupil illuminated, the convex 14 D, held between the forefinger and thumb of the surgeon's left hand, is brought up in front of the patient's eye and kept there in the perpendicular position, the Fig. 44. surgeon steadying this hand with the tip of the little finger on the patient's forehead. The convex glass is now removed just far enough from the patient's eye to cause the margin of the pupil to disappear out of the surgeon's field of vision. The observer then ceases to look into the eye, and fixes his gaze on the convex glass, when the inverted image of the fundus should at once become visible — and will seem to be situated in the convex lens, although it really is in the air somewhat this side of the lens. The diagram (Fig. 44) serves to illustrate the effect of in- version of the image. The left eye is seen in the upright image in the left-hand picture, while the same eye is seen in the inverted image in 62 DISEASES OF THE EYE. the right-haiid picture. 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 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 their condition. The reflex from the surface of the cornea gives a good deal of annoyance to every beginner. It cannot be done away with ; but, as it moves in the opposite direction to a motion of the object lens, it is possible to see past it. 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 convex lens, say -}- 20 D, be used, the reflections from it are more disturbing than from a lower number, say -J- 14 D. To examine The Optic Nerve, the surgeon sits in front of the patient, and directs him to turn his eye somewhat to the nasal side and slightly upward ; because the papilla is 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 the right and a little upward, say toward the surgeon's left ear- It is well always to seek out the optic papilla in the first instance, not only because it is so important a part of the fundus oculi, but because, examining from it toward the peri- phery, we are the better able to determine the locality of any pathological alteration. Should the patient not direct his gaze in such a way as to enable the surgeon to see the optic papilla or other desired region, it may be brought into view either by a motion of the surgeon's head in the opposite direction, or by a motion of the convex lens in the same direction, or by a combination of both these manoeuvres. THE OPHTHALMOSCOPE. 63 The Macula Lutea should then be examined. It may be seen by directing the patient to look straight at the hole of the ophthalmoscopic 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 crys- talline 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 right eye be under examination, and then by motions of the convex 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 upward, downward, to the right, to the left, etc. Estimation of the Kefraction by Aid of the Ophthalmoscope. From what has been said with reference to the Direct Method of ophthalmoscopic examination, it will have become evident that this method affords a means for determining the refraction of the eye. At a little distance from the observed eye into which light from the ophthalmoscopic mirror is thrown, the surgeon will be able to see some of the details of the fundus, if it be either myopic or hypermetropic ; but if it be emmetropic he will be unable to do so. The reason for this is that in myopia the rays coming out of 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 hypermetropia the rays coming out divergently from the eye 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, inasmuch as the 64 DISEASES OF THE EYE. rays come out parallel, those from any two points (m, n, Fig. 45) at a short distance from each 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 eye, or ob- tains only an indistinct image, or red glare. If he go very close to the eye, he can see details. If, on the observer moving his head from side to side, the ves- sels, etc., of the observed fundus move with him, the case is one of hypermetropia, because the image is an erect one, which is situated behind the plane of the pupil to which it is referred. If the vessels, etc., move in the opposite direction to that of the Fig. 45. observer's head, the observed eye is myopic, because there the image is inverted and in front of the pupil. For the quantitative determination of ametropia a refraction ophthalmoscope is required. This instrument provides a num- ber of convex and concave lenses, capable of being brought into position behind the sight-hole in rapid succession by a simple mechanism. It is necessary, in the first instance, that the surgeon be aware of the nature of his own refraction. If the Surgeon be Emmetropic, he can see the fundus oculi of an erametrope in the upright image without any lens, provided he go close enough ; as the parallel rays coming from the THE OPHTHALMOSCOPE. 65 examined eye will be focused 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 dioptries the eye wants of being emmetropic ; or, in other words, so that the rays coming from it may be made parallel. The lens which 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 hyperme- tropia. The emmetropic surgeon 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, and this is usually the case in the lower degrees of hypermetropia. The surgeon gradually relaxes his accom- modation 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 surgeon 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 is the measure of the myopia, as showing by how many dioptries it is in excess of emmetropia. The emmetropic surgeon 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 uses his accommoda- tion 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 6 66 DISEASES OF THE EYE. the importance of selecting the weakest concave glass with which the fundus is distinctly seen. If the surgeon be ametropia, he may either correct his ame- tropia by wearing the suitable lens, and then proceed as though he were emmetropic ; or else, and which is perhaps the better plan, he may add or subtract the amount of his ametropia from that of his patient's. For example : — The Hypermetropic Surgeon of, say 3 D, requires a -\- 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 requires a -f- lens of 6 D, the examined eye must be hypermetropic 3 D, the other 3 D going to correct the surgeon's H. If he be able to see the fundus oculi under observation without any lens, it shows that that eye has an excess of refraction corresponding to the want of refraction in his own eye — that is to say, it is myopic 3 D. If he require a concave 2 D, his want of refraction — his hyper- metropia — is not enough by that number of dioptrics, 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 -f- 1.0, 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., 3.0 — 1.0). If the Surgeon he Myopic, say 2 D, he requires a — 2 D to see the fundus of an emmetropic eye, this lens going wholly to correct his own ametropia. If he see the fundus with a — 7 D, the examined eye has M. 5 D, because 2 D has been used in cor- recting the surgeon's M. If he be able to see a fundus without any lens, the patient has H. 2 D, the want of refraction in the latter's eye compensating exactly for the excess of refraction in the surgeon's eye. If he find it necessary to use a + l^ns of 7 D, it will indicate that his excess of refraction is not able to make up for the defect of refraction in his patient's eye, and that the latter has H. = 9 D (2 D -f 7 D). If he have to use THE OPHTHALMOSCOPE. 67 a — lens, say — 1.0, which is less than his own correcting glass, this shows that the eye he is examining is hypermetropic to a lesser degree — in this instance by 1.0 D — than he himself is myopic, and the hvperraetropia here would be 1.0 D (i. e., 2 - 1.0). The Existence and Degree of Astigmatism may be Determined with 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 con- vex 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 ves- sels * seen without any lens, and the number of the lens indica- ting 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. If a concave lens be required to bring into distinct view the vessels in one meridian, while a convex lens is required for the * The vessels may be regarded as lines, and the explanation given on pp. 42 and 43 applies to them also. 68 DISEASES OF THE EYE. opposite meridian, the 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 hyper- metropia exists in the opposite meridian. I would again impress upon the reader the absolute necessity of thoroughly relaxing his accommodation in all examinations in the upright image. Paralysis of the patient's accommodation with atropine is necessary in most cases, where accuracy in the determination of the refraction with the ophthalmoscope is re- quired, and can hardly be done without in cases of hypermetropia and of hypermetropic astigmatism, owing to the cramp of ac- commodation which is almost always present. Ketinoscopy. Another and very useful method for determining the refrac- tion by the ophthalmoscope is termed The Shadow Test, or Re- tinoscopy. The appearances upon which this method depends are due to the play of light reflected from the mirror on the fundus oculi. Either a concave or a plane ophthalmoscopic mirror may be employed. I invariably use a plane mirror ; but, as I believe the majority of ophthalmologists still use the con- cave mirror in retinoscopy, I shall describe the theory and use of the method by its aid, and then that by aid of the plane mirror will be readily understood. If the rays from a light (i. Fig. 46) be reflected from The Concave Mirror (m) of an ophthalmoscope, they cross at a cer- tain point (A) and form there an inverted image of the flame, and then diverge again. If these diverging rays be made to pass through a convex lens {B) placed at such a distance in front of a screen {E) that the rays meet at a focus on the latter, a very small and brilliant upright image (0) of the flame is there formed, surrounded by a deep shadow. If the screen be moved slightly toward the lens (to H), so that the focus of the rays would lie behind it, or, if it be removed slightly away from the lens (to M), so that the focus come to lie in front of it, the brilliancy of the image on the screen and the intensity of the RETINOSCOPY. 69 surrounding shadow are reduced. Because, in each instance, a circle of diffusion, and not an accurate image, is formed on the screen, and the further the focus of the pencil of rays is situated from the screen in either direction, the weaker does the image become, and the more ill-defined the shadow. Fig. 46. If the mirror be rotated in various directions, the illuminated part * and the shadow are seen — care being taken to look at the screen directly, and not through the lens — to move on the screen * " The area of light," " the image," " the illuminated area, or part" of the fundus, and "the illumination," are different terms for one and the same thing. " The shadow " or " shade " refers merely to the mar- gin of the illuminated area, i.e.^ where the illumination ceases and dark- ness begins ; it does not mean that the shadow of any object is thrown on the fundus oculi. When we speak of the motion of the shadow, we mean that the margin of the illuminated area, or boundary- line between illuminated and non-illuminated area, moves along with the illuminated area in response to the motion of the mirror. It is easier to learn how the illuminated area moves by watching the margin of the shadow (which comes across the pupil from behind the iris like a revolv- ing shutter across a shop window), and hence we have come to talk always of the motion of the shadow, and not of the motion of the illuminated part. 70 DISEASES OF THE EYE. in the opposite direction to the motion of the mirror. For ex- ample, if the position m (Fig, 46) be given to the mirror, the path of the rays reflected from it is shown by the dotted lines, and the image of is moved to 0'. This will also be the case if the screen be at H or at M. These three positions of the screen may be supposed to represent emmetropia (E), hyperme- tropia (H), and myopia (M). Fig. 46 more particularly illus- trates the motion of the light and shade in ^ and ^only, while Fig. 47 demonstrates that of M. Fig. 47. In the eye, in like manner, the area of light and shade in the pupil moves against the motion of the mirror. Now, we cannot, of course, see the real motion on the retina directly, but only through the dioptric media, and they will influence the apparent motion according to the condition of the refraction. In emmetropia and in hypermetropia the rays coming out of the observed eye are parallel and divergent, respectively; and, consequently, an upright image being formed by them in the observer's eye, the true motion given by the mirror is perceived. In myopia, at least in all cases of more than 1 D, the observer does not see an upright image of the flame on the fundus of the RETINOSCOPY. 71 observed eye, but a real inverted aerial image formed between his mirror and the observed eye. The reason of this is, that the rays coming out of the patient's eye are convergent, and meet at a focus, which is the far point of the eye, and form there an inverted image of the object from which they come, and which, in this instance, is an upright image of the flame (the illumin- ated area). When, therefore, the upright image on the fundus moves against the mirror, the inverted image (which is what the observer sees) moves in the opposite direction, i. e., with the mirror. For example, if in Fig. 47 we suppose a to be the po- sition of the image on the fundus of a myopic eye, and cr the position of its real inverted aerial image, a motion of the mirror to m (the rays reflected from m are omitted, in order to avoid confusion in the diagram) throws the image of a to a\ as already explained, but the inverted aerial image of a' is formed at a" ; i. e., it seems to have moved with the mirror. In myopia alone, then, does the image move with the mirror ; while in emmetropia and hypermetropia it moves against the mirror. In low myopia (1 D and less), as will just now be seeu, the image also moves ao^ainst the mirror. From what has been said, it is evident that the higher the ametropia (the further from the screen, in Fig. 46, the focus of the rays) the larger and feebler the illumination becomes (i.e., the greater the circles of difiusion), and the more crescentic the margin of the shadow, because it is the margin of a circle of diff'usion. Again, the extent of the motion of the image and its rate are in inverse proportion to the degree of the ametropia. Thus, if Fig, 48 represent a myopic eye, whose far point is situated at cr, a motion of the mirror to m' may be supposed to throw the illuminated part to a, and then cr will move to cr. But, if the myopia be of less degree, so that the far point is at a^, the same motion of the mirror will throw a^ to a^, and the distance be- tween these two latter points is evidently much greater than that between a- and a-'. In a hypermetropic eye (Fig. 49) the image may be supposed to be formed at a, and a motion of the mirror 72 DISEASES OF THE EYE. to m' will throw it to a' ; while in a higher degree of hyperme- tropia it would be formed at h, and the same motion of the mir- ror would throw it to h'. The distance between b and h' is much greater than that between a and a'. In practicing retinoscopy with the concave mirror the surgeon Fig. 48. sits 1.20 m. in front of the patient. The eye to be examined is shaded from the direct rays of the lamp, if the latter be placed beside the patient; but a better plan is to have the light above his head. The focus of the mirror should be 22 cm., and any Fig. 49. error of refraction of the surgeon is to be corrected. The light is thrown into the eye at an angle of about 15° with its axis of vision, so that, if the pupil be not under the influence of atro- pine, the macula lutea may be avoided. In children, and when the pupil is very small, it is advisable to dilate it with atropine, RETIXOSCOPY. 73 and then the region of the macula lutea may be utilized. When now the ophthalmoscope is rotated in different directions, motions of the light and shade on the fundus oculi are seen in the pupil- lary area. The surgeon directs his attention to the edge of the shadotv rather than to the illuminated part, for its motion is more easily appreciated. If the edge of the shadow move with the motion of the mirror, myopia is present ; if it move against the mirror, emmetropia, hypermetropia, or myopia of 1 D or less is present. The reason why the motion is against the mirror in cases of M. 1 D and less is, that the surgeon being seated only 1.20 m. from the eye he is examining, if that eye have a myopia of 1 D, its far point is so close to his eye that he cannot clearly observe the image there formed ; but, if the myopia be of even slighter degree, the image will be formed behind the surgeon's head, and he gets a shadow moving against the motion of his mirror, be- cause the image he then sees is the upright one on the patient's fundus oculi, and not the inverted aerial image. We proceed as follows : 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 sur- geon 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 surgeon's eye, or behind his head, and he consequently gets a shadow moving against the mirror, although low myopia, and not emmetropia, is present. Consequently, — 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 7 74 DISEASES OF THE EYE. whether the eye be emmetropic, hypermetropic, or slightly my- opic. 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 against the mirror the case is one of hyper- metropia, and higher numbers are at once proceeded with, until that one is reached which causes the shadow to move with the mirror. The measure of the hypermetropia is 1 D less than the glass so found, for it has evidently over-corrected the defect. If, however, on putting on -j- 1 D we find the shadow to move with the mirror, we change it for -|- 0.5 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 -f- 1 D the shadow move with the mirror, while with -f 0.5 it continue to move against it, the eye is emmetropic. It may be found that in two opposite meridians there is a difi^erence in the motion of the shadow, and this leads us to diagnose the presence of astigmatism. When the difference is one merely of rapidity of motion or of intensity of illumination and shadow, we know that we have to deal with either simple or compound astigmatism. But if, in the two meridians, there be a difference in the direction of the motion, then it is a case of mixed astigmatism. The best method for ascertaining the degree of astigmatism and its correcting glass is to correct each of the principal meridians separately with spherical lenses. In compound astigmatism, the diflference between the two lenses found indicates the degree of astigmatism, and also the cylindri- cal lens which, combined with the correcting spherical lens for the least ametropic meridian, is required to neutralize the defect. In mixed astigmatism the addition of the two numbers gives the cylindrical lens, while one or other of them, usually the + Dj is used as the spherical lens. With Tlie Plane Mirror the source of illumination of the observed eye is not a real inverted image of the light, as in the case of the concave mirror, but a virtual upright image RETINOSCOPY. 75 behind the mirror ; and, as this image moves in the opposite direction to the motion of the mirror, the motion of its illu- mination on the fundus of the patient's eye must be uiih the mirror in all cases, and not against it, as in using the concave mirror. With the plane mirror, therefore, the shadow is seen to move ivith the motion of the mirror in H. and E. But in M. it seems to move against the motion of the mirror, for what we here see is an inverted' image of the fundus situated at the far point of the eye. If the myopia be high, this inverted image will be close to the eye; if low, it will be far away from it. In using the plane mirror it is important to remember this point, because, if the observer go nearer to a myopic eye than its far point, he will not obtain a myopic motion, but one which is the same as that in E. or H. Consequently, in using the plane mirror, the rule is to go as far from the eye under examination as possible. If, at the beginning, the surgeon retire a little more than two metres from the eye, and there obtain a with-motion, he at once knows that the eye is not myopic 0.5 D ; or, if he stand a little more than four metres away, and obtain the same motion, he knows there is not a myopia of even 0.25 D present. If the myopia be high, he will be able to begin close to the patient, but must gradually retire from the eye as he increases the number of the concave glass put up — for the far point is thereby moved further off— in order that he may not think he has corrected the myopia before he really has done so. Again, if at every distance the motion be with the mirror, the surgeon has to decide whether this indicate E. or H. He does this by putting a low lens, say + 0.25, before the patient's eye, and if then, standing at a dis- tance of four metres, the motion be altered by this glass to one against the mirror, he knows that the eye has not a hyperme- tropia of 0.25 D, consequently that it is emmetropic ; but if this lens do 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 76 DISEASES OF THE EYE. much more of H. than this may be present, it is now only neces- sary to go on increasing the strength of the lens in front of the patient's eye, until one is reached which, at four metres from the eye, produces the myopic motion. The observer knows that he has now slightly over-corrected the hypermetropia of the eye, and that the next lens lower is its measure. With some practice it is possible, unless the pupil be small, to obtain sufficient light from the fundus with the plane mirror at a distance of four metres. I find this method much more easily worked than that with the concave mirror. It has the advantage, too, of not requir- ing any wearisome addition to or subtraction from the data obtained. The pleasantest plane mirror is one of 4 cm. diameter, and of which the sight-hole is 4 mm. in diameter. FOCAL OR OBLIQUE ILLUMINATION is employed for the examination of the cornea, iris, and lens. With a high -\~ lens (16 to 18 D) the light of the gas flame is concentrated on the part to be examined with an oblique, not a perpendicular, incidence of the concentrated rays. Small foreign bodies in the iris, cornea, or lens, or opacities in either of the latter, can be thus detected. Extremely delicate opacities in the cornea are not seen best with the strongest illumination which can in this way be produced ; but, rather, by the half- light which is obtainable at the edge of the cone of light pass- ing from the lens. In examining the centre of the crystalline lens, the incidence of the light must necessarily be more per- pendicular. THE NORMAL FUNDUS OCULI. 77 THE NORMAL FUNDUS OCULI AS SEEN WITH THE OPHTHALMOSCOPE. RefereDce has been made to the enlargement of the image of the fundus oculi seen with the ophthalmoscope. The cause of this enlargement is, that the fundus is observed through a diop- tric system, at, or close to, the principal focus of which it is situated, and which, consequently, magnifies it to our view. The enlargement of the inverted image is not so great as that of the upright image, and it is smaller the shorter the focal length of the convex lens employed. The inverted image of a hyperme- tropic eye is larger than that of an emmetropic eye, and the latter larger than that of a myopic eye. It is possible to determine mathematically the degree of enlargement of the image. The 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. Occasion- ally 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, outside this again, by a more or less complete black line, the choroidal ring. The sclerotic ring is due to the choroidal margin not coming quite up to the margin of the papilla, the foramen in the choroid for the passage of the optic nerve fibres being some- what larger than that in the sclerotic, and, consequently, a narrow edging of the white sclerotic is exposed. The choroidal ring is the result of a hyper-development of pigment at the margin of the choroidal foramen. The complexion of the optic papilla 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 nerve fibres are often fewer than on the inner side. The apparent color of the papilla depends, also, upon the complexion of the rest of the fundus. If the latter be highly pigmented, the papilla appears 78 DISEASES OF THE EYE. pale in contrast ; while, if there be but little pigment in the choroid, 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 "Hyperemia of the papilla," where merely a high physiological complexion is present. A physiological excavation of the optic papilla is often met with. It is always on the temporal side of the papilla, and can be recognized from the parallax * which may be produced, and from the paleness of this portion of the papilla. When the exca- vation is very deep, one may sometimes observe the lamina cribrosa in the form of gray spots (the nerve fibres), surrounded by white lines (the fibrous tissue of the lamina). A physiological differs ophthalmoscopically from a pathological excavation, by the fact 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. Doubtless, in such cases, the thickness of the translucent nerve-fibre layer alone it is which is interposed between the sclerotic margin and the margin of the cup all round. The Normal Retina is so translucent that it cannot be seen ; or, at most, a shimmering reflection, or shot-silk appearance, is obtained from it, particularly about the region of the yellow spot and along the vessels, but also toward the equator of the eye, and especially in dark eyes and in young people. A peculiar, but physiological, appearance, known as " opaque nerve fibres," is occasionally seen. It is produced by some of the nerve fibres forming the internal layer of the retina regain- ing 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 * For explanation of the parallax see Chap. XII. THE NORMAL FUNDUS OCULI. 79 only, and hence are quite translucent. Instead of that, in these cases their fibres reflect the light strongly, giving the efl?ect of an intensely white spot, commencing at the papilla, extending more or less into the surrounding retina, and terminating in a brush- like extremity. 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. It is remarkable that this halo is not visible with the direct method of examination — a fact due, prob- ably, 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 red point, the fovea centralis. 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 choroid and in the pigment- epithelium layer of the retina. 1. If there be an abundant sup- ply of pigment in each of these positions, the choroidal vessels are greatly hidden from view, and the effect is that of a very dark red fundus. 2. If there he but little pigment in the pig- ment-epithelium layer, the larger choroidal 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 choroid, and the fundus is seen of a very bright red color, the choroidal vessels down to their fine ramifications being discernible. In albinos even the choroidal capillaries may be seen. The Retinal Vessels. — The arteries are recognized as thin, bright red lines running a rather straight course, in the centre of each of which is a light-streak due to reflection from the tense coat of the vessel. This light-streak divides the vessel into two red lines. The veins are darker, wider, and more tortuous in their course than the arteries, and, their coats not being so tense, the light-streak is very much fainter. 80 DISEASES OF THE EYE. 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. 50. The second branching may take place in the nerve itself; and, when this occurs, it will Fig. 50. I. n. s , Art. nas. sup.; a.n.i., Art. nas. inf.; a.t.s., a.i.i., A. temp. sup. and inf., v.n.s., v.n.i.. Ven nas. sup. and inf.; i- «. «., t;. <.i., Ven. temp. sup. and inf. ; a.m.c, v.m.e., Art. and ven. median; aw., v.m., Art. and ven. macularis.— (», to gape open *) of the bulbar conjunctiva, serous discharge, dusky redness and swelling of the eyelids — which makes it difficult to evert them — pain in the eyelids, often of a shooting kind, burning sensations in the eye, and photo- phobia. This first stage lasts from forty-eight hours to four or five days. Then begins the second stage, in which, owing to swelling of the papilke, 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 lids continues, the upper lid often becoming pendulous and hanging 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. Complications with corneal affections form the great source of danger from this affection. They occur in four different forms : I. Small epithelial losses of substance on any part of the cornea. If these occur at the height of the inflammation, they are apt to * Probably from the appearance produced when the conjunctiva in this condition is much elevated round the margin of the cornea. THE CONJUNCTIVA. 101 go on to form deep perforating ulcers. 2. The whole cornea becomes opaque (diffusely infiltrated), and toward its centre some grayish spots form, which are interstitial abscesses or puru- lent infiltrations. 3. The infiltration may form at the margin of the cornea, and extend a considerable distance around its circum- ference, giving rise to a marginal ring ulcer, and, later on, to sloughing of the whole cornea. 4. A clean-cut ulcer may form at the margin of the cornea without any purulent infiltration of the corneal tissue, and may also extend a long way round the cornea. Such ulcers are particularly apt to occur where there is much chemosis which overlaps the margin of the cornea; and, being hidden in this way, these ulcers 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 ophthalmia neonatorum and in gonorrhceal ophthalmia. They may appear at any period of the affection, but the earlier they occur, the more likely are they to result seriously. The danger of these ulcers consists in the perforation of the cornea they are apt to produce, of which more later on. The severer the case, especially the more the bulbar conjunc- tiva is involved in the process, the more likely is it that corneal complications will arise. For the corneal process is to be re- garded as the result of infection by the conjunctival secretion ; and this infection is all the more apt to occur where the nutrition of the cornea is impeded by a dense chemotic swelling of the bulbar conjunctiva. Severe chemosis is less common in the blennorrhoea of the new-born than in gonorrheal ophthalmia, and this is the chief reason for the fact that the latter is the more dangerous affection of the two. Treatment. — The prophylaxis of purulent ophthalmia must here first engage our attention. The prophylaxis of blennorrhoea neonatorum is a most impor- tant matter, and 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 102 DISEASES OF THE EYE. the infant immediately after birth with a non-irritating disinfect- ant {e.g., a solution of corrosive sublimate 1 in 5000) are to be recommended. The method of Dr. Crede has found very general acceptance, and is a good one. It is as follows: When, after division of the umbilical cord, 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. Dr. Crede and many other obstetri- cians employ this method now, in a routine manner, in their lying-in hospitals, for all the infants, whether or not it be sus- pected that there is danger of infection ; and by its aid Crede reduced the percentage of his cases of ophthalmia neonatorum from 8 or 9 per cent, to 0.5 per cent. The action of the nitrate of silver solution depends, probably, upon the destruction of the superficial layers of the conjunctival epithelium and of the gouococci contained in them. Other anti- septic applications which have been tried do not act as well, for they do not destroy the superficial epithelium. In all cases of gonorrhoea it is the duty of the surgeon to ex- plain to his patients what is the danger of their carrying any of the urethral discharge to their eyes, and to charge them to exer- cise punctilious cleanliness 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 once broken out : in the commencement of the affection, the only local appli- cations admissible are antiseptic lotions (boric acid, corrosive sublimate) and iced compresses, or Leiter's tubes. With the former the conjunctival sac should be freely washed or irrigated, not syringed out. In syringing out the conjunctival sac, a morsel of the corneal epithelium may be removed, and through this the cornea become infected, and therefore this method is objectionable. 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. In this and in the next stage THE CONJUNCTIVA. 103 the cheraosis should be freely, and daily, incised with scissors. If the swelling of the lids be great, the external canthus should be divided with a scalpel, from without, leaving the conjunctiva uninjured, 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 leaching at the external canthus, and, in many cases, is of great benefit at the very commencement. If, ia adults, the chemosis, palpebral swelling, and rapidity of the onset, indicate that the inflammation is severe, it is, in my opinion, well to place the patient quickly under the influence of mercury by means of inunctions, or small doses of calomel, as by this means the chemosis is often rap- idly brought down and one source of danger to the cornea re- moved. In the second stage, i. e., when the conjunctiva has become velvety and the discharge purulent, caustic applications are the most trustworthy, and in this respect iodoform and other lauded means cannot compete with them. The application employed may be a solution of nitrate of silver of 15 to 20 grains in 5J of water, which should be applied by the surgeon to the conjunctiva of the everted lids and then neutralized with a solution of com- mon salt, as described when discussing the treatment of simple catarrhal conjunctivitis. Or, the solid mitigated nitrate of silver (one part nitrate of silver, two parts nitrate of potash) may be used, the first application being mild, in order to test its effect, while careful neutralization with salt water and subsequent wash- ing with fresh water are most important. The immediate effect of a caustic application to the conjunc- tiva is the production of a more or less deep slough, under which a serous infiltration takes place. This latter increases, and finally throws oflT the slough, and then the epithelium begins to be re- formed. From the time the slough separates until the epithelium has been regenerated, a diminution in the secretion may be noted, but the discharge again increases as soon as the regener- ative period is ended, and this now is the moment for a new application of the caustic. From one caustic application of 104 DISEASES OF THE EYE. ordinary severity until the end of the regenerative period about twenty-four hours usually elapse. Inamediately after a caustic application iced compresses should be used for thirty minutes or longer. Between the caustic applications the pus should be fre- quently washed away from the eyelids, and from between the eyelids, with a 4 per cent, solution of boric acid, or with a 1 in 5000 solution of corrosive sublimate, and boric acid ointment should be smeared along the palpebral margins to prevent them from adhering and thus retaining the pus. No corneal complication contraindicates the active treatment of the conjunctiva by the method just described. Iodoform, finely pulverized, 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 my part, I should trust to it in mild cases only. When one eye is affected, it is important to protect its fellow from infection by means of a hermetic bandage. This may be made by applying to the eye a piece of lint covered with boracic acid 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 gutta-percha 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 Buller are very serviceable for this purpose. Treatment of Corneal Complications. — Many surgeons, I under- stand, use solution of the sulphate of eserine (gr. ij ad aq. f.^j) dropped into the eye as soon as any corneal complication arises, and as long as it continues, on the ground that this drug is be- lieved to have the effect of reducing the intra-ocular tension (a circumstance to be desired in these instances), and also to act as an antiseptic. Its power to reduce the normal intra-ocular tension is not great, and its antiseptic action, if it exist, must be very insignificant, while, in my opinion, it has a decided tendency to promote iritis in these cases, where the iris is liable to become inflamed secondarily to the corneal process. I therefore do not THE CONJUNCTIVA. 105 recommend its use in these cases. I employ atropine here with the object of diminishing the tendency to iritis. Only if a marginal ulcer should perforate, with prolapse or danger of pro- lapse into the opening, is eserine indicated, and then simply for the purpose of drawing the iris out of or away from the perfora- tion, by the contraction of its sphincter. On the first appearance of an ulcer or infiltration of the cor- nea, besides the use of atropine, nothing can be done further than the steady continuance of the conjunctival treatment, no remission or relaxation of which is indicated, or, indeed, admissible. Greater care is now required in everting the lids, lest pressure on the globe might cause rupture of the ulcer ; and it should 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 pur- poses 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 progresses toward cure, infiltrations becoming absorbed and ulcers filled up. But, even though the conjunctiva be improving, and still more so if it be not, the corneal process may progress, the infiltration becoming an ulcer, and the ulcer becoming gradually deeper, until, finally, it perforates. Should a corneal ulcer become deep, and seem to threaten to perforate, paracentesis of the floor of the ulcer must be resorted to without delay. By thus forestalling nature, a short linear opening is substituted for the circular loss of substance which would have resulted in the ordinary course of events. Through this small linear opening no prolapse of the iris, or else a rela- tively small one, takes place; and, consequently, the ultimate state of the eye is usually a better one than it would otherwise be. The reduction of the intra-ocular tension after the para- centesis promotes healing of the ulcer. It is often desirable to evacuate the aqueous humor by opening the little incision in the 106 DISEASES OF THE EYE. floor of the ulcer with a blunt probe, on each of the two days after the operation. If an ulcer perforate spontaneously, the aqueous humor 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 dis- tensor of the opening, causing fresh infiltration of its margins. In either case cicatrization 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- protrusions down to a level with the cornea ; or, if large, to cut a small bit off" their summits with the object of obtaining flat cicatrices. Horner "^ pointed out that, in cases of blennorrhoea, * Gerhardt's "Handbuch der Kinderkrankheiten," Bd. v, Abth. 2, p. 268. THE CONJUNCTIVA. 107 this proceediDg opens a way for purulent infection of the deep parts of the eye, and that serious consequences are not rare. He confined interference with the iris in these eyes to incision of the prolapse, when it seems to be acting as a distensor of the open- ing, causing fresh infiltration of the cornea. Under other cir- cumstances he restricted his treatment of the prolapse to the instillation of eserine, which has a marked effect in diminishing the size of the protrusion. It may occur that on the surgeon's visit to a case of blennor- rhoea of the conjunctiva he will find the margins of the eyelids 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 thoroughly wash 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 its anterior capsule, comes to be applied to the posterior aspect of the cornea. The pupillary area is soon filled with fibrinous secretion. The opening in the cornea ultimately becoming closed, the iris and lens are pushed back into their places by the aqueous humor, which has again collected. Adherent to the anterior capsule on the spot which lay against the cornea is a morsel of fibrin, which gradually becomes absorbed by the aqueous humor. In the mean- time changes have been produced by this exudation on the corres- ponding intra-capsular cells, which result in a small, permanent, central opacity at that place, where there is also a slight eleva- tion of pyramidal shape over the level of the capsular surface. This condition is called central capsular cataract, or pyramidal cataract, and rarely results from corneal perforation in adults. In cases of blennorrhoea nepnatorum an inflammatory swelling of the joints, so-called gonorrhoeal arthritis, is very occasionally seen. Deutschmann * found the gonococcus in the fluid removed ^ Arch, filr Ophthal., xxxvi, 1, p. 109. 108 DISEASES OF THE EYE. from the joints in two such cases, while other observers found in their cases only the usual pyogenic cocci. Croupous Conjunctivitis. — This is a disease of early childhood, and is not common. The palpebral conjunctiva is a good deal swollen, and is covered with a false membrane that may be peeled off, leaving a mucous surface underneath, which bleeds little or not at all. The disease is not a severe one, and does not cause secondary corneal affections unless when the bulbar conjunctiva very rarely participates in the attack. It must not be mistaken for diphtheritic conjunctivitis, from which it is read- ily distinguished by the ease with which in it the false membrane can be removed, and by the vascular condition of the underlying mucous membrane. This is, in fact, nothing more than a severe form of catarrhal conjunctivitis, in which the secretion happens to be rich in fibrine, and hence possessed of a marked tendency to coagulate on the surface of the conjunctiva. Causes. — Contagion, Epidemic. Treatment. — Iced compresses, or Leiter's tubes, to the eyelids during the croupous stage, with antiseptic cleansing of the con- junctival sac (Sol. Hydrarg. Perchlor. 1 in 5000, or Sol. Acid Borac. 4 per cent.). No caustic should be used in this stage, as it is apt to produce corneal changes. Sulphate of quinine sprinkled on the conjunctiva is praised by some surgeons as a useful application at this period. When the false membrane ceases to be formed a slight blennorrhcea comes on, and this is to be treated with nitrate of silver applications in the usual way. 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. Fortu- nately, it is almost unknown in these countries, while in Berlin it used to be so frequent that von Graefe set apart two wards for it in his hospital, which were under my care as his assistant. It is now a much less common disease there, owing probably to the improved hygiene of the city. The subjective symptoms of its initial stage are similar, THE CONJUNCTIVA. 109 although severer, especially iu the matter of pain, to those of blennorrhoeic conjunctivitis. The objective symptoms differ from those of blenuorrhoea in that the lids are excessively stiff, owing to plastic infiltration of the subepithelial and deeper layers of the conjunctiva, while the surface of the mucous membrane is smooth and of a grayish or pale-buff color. If an attempt be made to peel off some of the superficial exudation the surface underneath will be found of the same gray color, not red and vascular, as in croupous conjunctivitis. 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. Toward 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 blennorrhoeic stage. A third stage is formed by cicatricial alterations in the mucous membrane, which often lead to symblepharon or to xerophthalmos ; so that, even if the eye escape corneal dangers in the first and second stages, others almost as serious may await it in the final stage. Corneal complications are most likely to occur iu 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 blennorrhoeic stage come on before corneal complications appear, or even before an ulcer contracted in the first stage has advanced far, they are more easily managed. Causes. — It is difficult to assign a cause for this disease, which chiefly attacks children. It is frequently epidemic, is extremely infectious, and, although similar in its nature, is rarely, if ever, found in connection with an attack of diphtheritis of the fauces. Treatment. — In the first stage, frequent warm fomentations, with antiseptic cleansing, are the only local measures admissible. No caustic or astringent application should be used. Internally, the patient should be treated with iron and quinine and generous diet. In the second, or blennorrhoeic stage, careful caustic appli- 110 DISEASES OF THE EYE. cations are to be used. Corneal ulcers must be dealt with when- ever they arise, in the same way as though the case were one of blennorrhceic conjunctivitis. When the purulent discharge ceases, solutions of soda, milk, or glycerine may be prescribed as lotions for the conjunctiva, to arrest, if possible, the xerophthalmos. Conjunctival Complication of Smallpox. — Of this I have, for- tunately, too little experience to enable me to speak authorita- tively. The following embodies the views of the late Professor Horner,* who studied the subject during an epidemic in 1871. A good deal of uncertainty prevailed previously, for the initial stages of the eye affection were not carefully observed by physicians, owing to the swelling of the eyelids, while the ophthalmologist saw only the results of the process in the period of convalescence. Smallpox pustules on the cornea are, Horner believed, extremely rare; indeed, he saw but one such case. The most frequent, and most serious, mode of attack consists in a grayish- yellow infiltration in the conjunctiva close to the lower margin of the cornea, not extending to the fornix conjunctivae, nor far along the inner or outer margin of the cornea. It occurs in the eruptive stage, and is to be regarded clinically as a variola pustule. This infiltration or pustule gives rise to a corneal affec- tion, as does a solitary marginal phlycteuula, either in the form of a marginal ulcer, or as a deep purulent infiltration, ulcerating, perforating, leading to staphyloma, purulent irido-choroiditis, and panophthalmitis ; results which are often first observed long after the primary conjunctival affection has disappeared. Horner believed that the germ of the conjunctival infiltration makes its way between the eyelids, and that the constancy of the position of the infiltration is accounted for by this theory, that part of the conjunctiva, with closed eyelids and eyeball con- sequently rotated upward, being the most exposed to particles entering. Treatment. — On this ground he recommended the prophylactic *Loc. ciL, p. 297. THE CONJUNCTIVA. Ill use of boracic acid ointment on lint applied over the eyelids. If a conjunctival pustule have already formed, without any, or only commencing, corneal affection, he would destroy the pustule with fresh chlorine water, or with mitigated lapis carefully neutralized. Corneal complications are treated as in blennorrhoea of the conjunctiva or diphtheritis. The frequency with which the eyes become affected varies in different epidemics. As true post-variolous eye-affections, Horner recognized diffuse keratitis, iritis, and iridocyclitis, with opacities in the vitreous humor and glaucoma. In the hemorrhagic form of the disease, hemorrhages in the conjunctiva and retina; and, where pyaemic poisoning comes on, septic affections of the choroid and the retina take place. Amyloid Degeneration. — This rare disease attacks chiefly the palpebral conjunctiva, but is also seen in the bulbar portion. It causes great tumefaction of the affected lid, without any inflam- matory symptoms. The eyelid can be but partially elevated, and is often so stiff and hard that it can be everted only with difficulty. The conjunctiva has the appearance of white wax. The disease ultimately extends to the tarsus, but is a strictly localized process and not associated with amyloid disease in any other part of the system. It sometimes seems to be developed from granular ophthalmia, but occurs also as a primary disease. The positive diagnosis can be made by submitting a small portion of the diseased conjunctiva to the iodine test. Hyaline Degeneration of the conjunctiva has also been ob- served. It cannot clinically be distinguished from Amyloid Degeneration, and is really an early stage of the latter condition. Treatment consists in the removal of the diseased parts, by the knife and scraping, so far as may be possible. Tubercular Disease of the Conjunctiva. — This is an extremely rare disease. It commences in the palpebral conjunctiva of the upper lid usually, very rarely in the bulbar conjunctiva, as small, round, yellowish-gray nodules, which soon ulcerate. The margins of these ulcers are well defined, and their floors of a yellowish 112 DISEASES OF THE EYE. lardaceous appearance, or covered with grayish-red granulations. The surrounding conjunctiva 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 may also extend to the bulbar conjunctiva, and the cornea may become covered with pannus. The pre-auricular and submaxillary glands usually become enlarged. The positive diagnosis of the nature of the disease should be made by an examination of portions of the floor of the ulcer for the charac- teristic tubercle bacillus, which will distinguish this from second- ary syphilitic ulceration of the conjunctiva, between which and the tubercular ulceration there is sometimes a resemblance. 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. This is a very chronic disease, its progress sometimes extend- ing over many years, and it is rarely met with except in youth. Some of those whose eyes are attacked are already the subjects of tuberculosis in other organs, but very many of them are per- fectly healthy in that respect. In fact, we have reason to believe (Valude, Leber) that tuberculosis of the conjunctiva is much more often a primary disease, the result of an ectogenic infection, even in cases where already tuberculosis exists elsewhere, than of infection occurring through the blood. Tubercle bacilli intro- duced into the normal conjunctival sac have, it is true, been found to be harmless, for the intact epithelium offers an insuper- able 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 estab- lished. The frequent lodgment of foreign bodies under the upper lid explains why this is the most common place for the disease to begin in. But, although conjunctival tubercular dis- ease is not often secondary to tubercular disease in other parts of the system, yet it is itself liable to be the starting-point of gen- eral tuberculosis. Treatment. — The fact last mentioned makes it most important, THE CONJUNCTIVA. 113 in cases of primary tubercular disease of the conjunctiva, to thoroughly eradicate the disease, so as to avert an infection of other organs, and this can often be effected. If the ulcers be not already too extensive they must be scraped, and the actual cautery freely applied to them ; and, where the disease has already spread to the cornea, sclerotic, iris, or choroid, enuclea- tion of the eyeball is instantly called for. Lupus of the conjunctiva usually occurs as an extension of the disease from the surrounding skin. It is seen as a patch or patches of ulceration, covered with small, dark-red protuber- ances or granulations, chiefly on the palpebral conjunctiva, which bleed easily on being touched. Like lupus of the skin, these ulcerations undergo spontaneous healing and cicatrization in one place (unlike tubercular ulcera- tion in that respect), while they are still creeping over the sur- face in another direction. But we now know that lupus, when- ever it occurs, is really a tubercular disease, and that the two forms differ only in their clinical appearances. The Treatment is scraping with a sharp spoon, and the appli- cation of the actual cautery. 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 lach- rymation, and the conjunctiva, at each place where subconjunc- tival exudation of serum has been situated, undergoes degener- ation 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 destroyed and the eyelids are adherent to the eyeball. The cor- nea gradually becomes completely opaque, or, having ulcerated, becomes staphylomatous. In the course of the disease the eye- lashes are apt to become turned in on the eyeball, or even entro- pion may form; and these conditions aggravate the suffering of the patient. The foregoing is a description of a severe case. In less severe 10 114 DISEASES OF THE EYE. cases the conjunctiva may not be completely destroyed, and the cornea may not be affected. The formation of a true bulla hardly ever occurs, for the con- junctival epithelium is so delicate that it cannot be disturbed in this way by the serous exudation beneath it, but rather breaks down at once. Consequently 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 ; and these appearances have led to the mistaken diagnoses of croupous, or diphtheritic, conjunctivitis. Treatment is helpless in respect of arresting the progress of the disease or of restoring sight when lost in consequence of it. The most one can do is to relieve the distressing symptoms by emol- lients to the conjunctiva, and by the use of closely-fitting goggles, to protect from wind, dust, ^]^- ^^' and sun. Internally, arsenic is indicated. Xerosis, or Xerophthalmos, is a dry, lustreless condition of the conjunctiva, associated, in the severer forms, with shrinking of the membrane. There are two forms of the affection — the parenchyma- tous and the epithelial. In Parenchymatous Xer- ophthalmos there is a more or less extensive cicatricial de- generation of the conjunctiva, dependent upon changes in its deeper layers, while its surface and thatof the cornea become dry and the latter becomes opaque, and the eye conse- quently sightless. The conjunctiva shrinks so completely, in many of these cases, that both lids are found adherent in their 'v- ' THE CONJUNCTIVA. 115 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 epithelium, fat, etc., peel away. The motions of the eyeball are restricted in proportion to the extent of the con- junctival degeneration. There is no cure for this condition. Fig. 53 represents a case of xerophthalmos, the result of pem- phigus, which was under my care in the National Eye and Ear Infirmary. 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, and the condition is said to be very occasionally seen as a primary dis- ease, described as essential shrinking of the conjunctiva. Many observers altogether deny the existence of the primary aflfection, and maintain that the cases described as of that nature are merely the results of pemphigus, and I am inclined to agree with this view. Treatment. — As cure is impossible in this form of xerophthal- mos, 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. Epithelial Xerosis of the conjunctiva is confined to the epithelium of that part of the conjunctiva which covers the ex- posed portion of the sclerotic in the palpebral opening. It there becomes dry and dull and covered with small white spots ; while 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 epi- demics, but also sporadically, accompanied, oddly enough, by night-blindness (the light-sense unimpaired) and contraction of the field of vision. The combined condition has been noticed chiefly in persons of debilitated constitution, who have been ex- 116 DISEASES OF THE EYE. posed to strong glares of light, and is said to have appeared in epidemics, under these conditions, in foreign prisons and barracks. Treatment by rest, protection from glare of light, nutritious diet, and tonics, invariably restores the eyes to their normal functions. Again, epithelial xerosis occurs in very young children in con- nection with a destructive ulceration of the cornea (see Infantile Ulceration of the Cornea with Xerosis of the Conjunctiva, Chap. VIII). Pterygium {-ripo^, a iving). — This is a vascularized thicken- ing of the conjunctiva, triangular in shape, situated most usually to the inside of the cornea, sometimes to its outer side, and rarely either above or below it. The apex of the triangle, the " head " of the pterygium, is on the cornea ; and its base, the " body," at the semi-lunar fold. The " neck " of the pterygium is that part of it at the margin of the cornea. There is frequently, but not always, a tendency of the growth to advance into the cornea, of which it seldom reaches the centre, and still more rarely extends quite across it. In its early growth the pterygium is rather 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 pterygium extend over the pupillary region of the 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, the disfigurement alone is what brings these cases to the surgeon. Cause. — The starting point of a pterygium is often an ulcer at the margin of the cornea, which in healing catches a morsel of the limbus conjunctivae and draws it toward the cicatrix, throw- ing the mucous membrane into a triangular fold. The ulcer then forms anew in the cornea immediately inside the cicatrix, and, in healing, the point of conjunctiva is drawn into it again, and is carried a little further into the cornea, and so on. The THE CONJUNCTIVA. 117 hollow lying between a Pinguecula (see below) and the margin of the cornea is apt to lodge small foreign bodies, which cause shallow marginal ulcers, and these, in healing, draw the Pingue- cula over on the cornea. A marginal ulcer in phlyctenular keratitis or in acute blennorrhoea may serve the same end. The only objection to this theory of the causation of pterygium is that an ulcer is not always to be found at the head of the growth. Pterygium is a rare affection in this country, but is more com- mon in countries or localities where the air is filled with fine sand, or other minute particles. Treatment. — Unless the pterygium be very thick, and have invaded 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, a quite normal appearance is not given to the eye, for a mark is necessarily left both on cornea and conjunctiva. If it be pro- gressive, or very disfiguring, it should be removed, other pro- posed modes of dealing with it being futile. This may be effected either by ligature or excision. 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 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. The dissection is continued toward the base of the pterygium, where it is finished with two convergent incisions meeting at the base. The mucous membrane in the neighborhood of the base is separated up somewhat from the sclerotic, and the margins of the conjunctival wound are then carefully brought together with sutures. Pinguecula (pinguis,/aO is the name given to a small, yellow- ish elevation in the conjunctiva near the margin of the cornea, usually at its inner side, more rarely at its temporal margin, but 118 DISEASES OF THE EYE. sometimes in each place. It contains, notwithstanding its name, no fat, but is composed of connective tissue 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 treat- ment, unless it become very disfiguring, when it may be removed with forceps and scissors. Subconjunctival Ecchymosis. — The rupture of a small sub- conjunctival vessel in the bulbar conjunctiva, without conjunc- tivitis, 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 in old people, but may occur in the young, and even in children from severe strain- ing, as in whooping cough, vomiting, or raising heavy weights. It is occasionally significant of diabetes. It also occurs some- times during epileptic fits, and profuse subconjunctival hemor- rhage is occasionally found in cases of fracture of the base of the skull, 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. — None is required, the extravasated blood gradu- ally becoming absorbed. Polypus of the conjunctiva, for which it is difiacult to assign a cause, is sometimes seen. It is generally small, in connection with the semi-lunar fold or caruncle, and can readily be removed with the scissors. Granula- FiG. 54. tions occurring after teno- tomy for strabismus are some- times, and incorrectly, called polypi. Dermoid Tumors. — These are pale yellow in color, and in size from that of a split pea to that of a cherry. They are smooth on the sur- face, and sometimes have fine hairs, and sit usually at the outer and lower margin of the cornea, but Fig. 54 was drawn THE CONJUNCTIVA. 119 from a case on which I operated, where the dermoid was situated on the inner side of the cornea, and not at the most usual seat extending over somewhat on the latter. In structure they resemble that of the skin. They are congenital tumors, sup- posed to be due to an arrest in development, but they often have a tendency to extend over the cornea. If this tendency be present, the tumor must be removed by dissecting it off the cornea, care being taken not to go into the deep layers of the latter. Syphilitic Disease of the Conjunctiva occurs both as primary and as secondary disease. It will be treated of in Chap. VI, on Diseases of the Eyelids. Papilloma, or Papillary Fibroma. — This is a non-malignant growth which may spring from any part of the conjunctival sac. It appears in the beginning as a small, round, red knob. The papillomata growing from the tarsal conjunctiva and from the semilunar 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 conjunctiva is a favorite seat for a papilloma, and in the early stage it may be impossible to distinguish it from an epithelioma. But if the case come under observation at a later stage, when the growth has overlapped the cornea, this difficulty does not arise, for the papilloma merely lies on the cornea, and can be lifted freely off it with a probe, while the epithelioma infiltrates the corneal tissue. Treatment. — Thorough removal with knife or scissors, and actual cautery, as otherwise the growth is liable to recur. Epithelioma is not common as a primary disease of the con- junctiva. When it is so found, it is seen as a little, nou-pigmented tumor growing from the limbus of the conjunctiva, surrounded by vascularization, and may in this stage be mistaken for a phlycten- ula — of which, however, the margins are not so steep — or for a papilloma (vide sujjra). As the tumor increases in size, it becomes lobulated and ulcerates, and soon attacks the cornea, giving 120 DISEASES OF THE EYE. rise on the latter to an appearance very like pannus. The neighboring lymphatic glands become enlarged. Sarcoma, too, is rare, and also takes its origin in the limbus conjunctivae. It is usually a pigmented tumor, a melanosar- coma. It does not attack the cornea so readily as the epithelio- matous growths, although it often overlaps the surface of the cornea. In its later stages this tumor grows to an enormous size. That these sarcomata are pigmented is explained by the fact that the limbus contains pigment, although usually so slight in amount as not to be visible to the naked eye. Treatment — Both epithelioma and sarcoma of the conjunctiva demand prompt operative removal, in order to prevent an exten- sion of the growth to the rest of the eye, if the case be seen early, as well as to avert metastases to other organs. The knife and actual cautery may save the eye and the life in the early stages ; but, later, removal of the whole eye is often called for. 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 con- tents 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. They are, very probably, dilated lymphatic vessels. These simple cysts are most commonly congenital, but they may begin to be developed during life. Treatment. — The cyst may be dissected out, or it may be suffi- cient to abscise its anterior wall. Subconjunctival Cysticercus is a little more common than simple cyst of the conjunctiva, and yet only forty-six examples of it have been placed on record. Of these the most recent is Dr. Louis Werner's case.* * Tran. Ophthal. Soc, ix, p. 74. The literature of the subject is there fully given. THE CONJUNCTIVA. 121 Cysticercus is distinguished from simple cyst by its free mobil- ity under the coDJuiictiva, 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 and looked on by him as pathognomonic of a cysticercus. This spot indicates the position of the receptacu- lum; and occasionally, wdien this comes to be placed on the posterior surface of the cyst, it may be difficult or impossible to make the diagnosis with certainty. 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 out through the opening. Lithiasis consists in the calcification of the secretion of the Meibomian glands, which are seen as little, brilliantly white spots not larger than a pin's head, in the conjunctiva. There may be one only, or v€ry many. These concretions 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 cocainized — must be separately removed by a needle, with which first an incision has been made into the conjunctiva over the concretion. Injuries of the Conjunctiva. — Foreign bodies frequently make their way into the conjunctival sac and cause much pain, espe- cially 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 drawing down the latter, and, provided it be not actually embedded in the mucous membrane, it is easily removed with a camel's hair pencil or with the corner of a soft pocket-handkerchief 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 be embedded in the conjunctiva, it must be pricked out of its position with the point of a needle or other suitable instrument, and the little proceeding will be made easier, 11 122 DISEASES OP THE EYE. both for patient and surgeon, by the instillation of a few drops of solution of cocaine (two per cent.) into the eye.* The conjunctiva is frequently injured in severe wounds of the eyelids or eyeball. The interest and treatment centre, here, chiefly on the other more important parts which have been injured. A tear or wound of the conjunctiva (usually of the bulbar por- tion), 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. The 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 alkaline solution ; while, in the case of lime, a weak solu- tion of a mineral acid is indicated for the purpose. Cocaine may be employed to relieve the pain. Subsequently, protection of the eye, with the use of olive or castor oil dropped into it, will best pro- mote the healing process. 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- scured. No measures taken during the healing process can pre- vent 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. VI, on Diseases of the Eyelids. * The continuous, or frequently recurring, sensation of a foreign body in the conjunctival sac, while nothing of the kind, nor any hyperaemia, is present, is sometimes a premonitory sign of mental disease. CHAPTEK V. PHLYCTENULAR, OR STRUMOUS, CONJUNC- TIVITIS 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; and, therefore, I treat of it here as one disease ; and, being a very im- portant disease, I devote a special chapter to it. It is important because it is excessively common, and because it is capable of causing considerable damage to sight. Moreover, even when it occurs on the cornea, it should probably be regarded as a con- junctival disease, for the corneal layer, which it primarily attacks, is the epithelium, and this — if not also, as some authors state, Bowman's membrane and the anterior layers of the true cornea — as we know from the foetal development of the mem- brane, is a continuation of the conjunctiva, in a modified form, over the cornea. t Hornert termed it Eczema of the Conjunctiva and Cornea. It is characterized by the eruption of phlyctenule (cr/'jz7ar>a, a vesicle, or pustule) on the conjunctiva bulbi (but never on the palpebral conjunctiva), on the conjunctival limbus, or on the cornea, and is chiefly a disease of children up to the eighth or tenth year of age. * Kipac^ a horn. t The posterior epithelium — or even, according to some, this along with the membrane of Descemet and the posterior layers of the true cornea — is to be reckoned to the uveal tract ; while the true cornea — or, according to some, only its central layers — is a modification of the sclerotic. X Loc. cit., Bd. V, Abth. 2, p. 279. 123 124 DISEASES OF THE EYE. Notwithstanding the derivation of the word, a phlyctenula, or phlyctene, is originally neither a vesicle nor a pustule; but, when on the conjunctiva, is a solid elevation consisting of a col- lection of lymph cells, and is of a grayish color. In a late stage, or under unsuitable treatment, the phlyctenula may, it is true, become a pustule. On the conjunctiva two types of the disease may be recognized : — 1. The Solitary, or Simple, Phlyctenula. — Of this there may be one or several, varying in size from 1 mm. to 4 mm. in diameter. The vascular injection is immediately around the phlyctenula, and is not diffused over the conjunctiva. At first there may be shooting pains and lachrymation, but these soon pass away. If the phlyctenuhe be not seated close to the cornea, the affection is not serious ; and the length of time required for its cure de- pends on the size of the phlyctenuke, varying from seven to fourteen days, as a rule. 2. Multiple, or Miliary, Phlyctenulse. — These are very minute, like grains of fine sand, and are always situated on the limbus of the conjunctiva, which is swelled. The general injection and swelling of the conjunctiva are considerable ; and occurring, as it/loes, almost exclusively, in young children, the affection may be called Eczematous Conjunctival Catarrh of Children (Horner). The irritation, and so-called photophobia, and lachry- mation, are often considerable, and there is a good deal of con- junctival discharge. This form is very apt to appear after measles and scarlatina. Bothfonm are liable to extend to the cornea, and then, only, does the disease become serious. This event may come about in the following different ways: — The Solitary Phlyctenula may be seated partly on the limbus conjunctivae 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 progressive riband- like corneitis (Fascicular Keratitis), the pustule becoming an PHLYCTENULAR OPHTHALMIA. 125 ulcer, at the margin of which the corneal epithelium is raised and infiltrated in crescentic shape. This now steadily advances for many weeks toward 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 con- sequent reflex blepharospasm. A permanent mark indicates the track of the ulcer. The Multiple Miliary Phlyctenulse on the limbus conjunctivae may cause some slight superficial infiltration and vasculariza- tion of the cornea in their immediate neighborhood, which pass off when the phlyctenule disappear. 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, and is termed a Ring Ulcer. It is a serious form of ulcer, for, if it extend far round, it may destroy the cornea in a few days by cutting off its nutrition. Primary PMyctenular Keratitis occurs principally in three diflferent forms : 1. Very small gray subepithelial infiltrations, which are apt to turn into small ulcers and then heal, leaving a slight mark. This mark may ultimately quite disappear, especially in the case of children and when situated peripher- ally. 2. Somewhat larger and deeper infiltrations, resulting in ulcers of corresponding size, which heal by aid of vasculariza- tion 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, 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. 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 126 DISEASES OF THE EYE. complete relief. The explanation of this reflex blepharospasm has been given by Iwanoff,* who showed that the round cells, in making their way from the margin of the cornea to their position under the epithelium, follow the course of the nerve filaments, which they irritate in their progress. The accompanying Figs. 5d and 56 are from his original paper. Eczema of the eyelids, face, and external ear, and catarrh of Fig. 55. -- C E, Epithelium ; B, Ant. elastic Lamina; C, True Cornea ; N, Nerve Filament, with Lymph Cells on its Course ; D, Phlyctenula. the Schneiderian mucous membrane, frequently accompany phlyctenular conjunctivitis and keratitis. In these cases, in children of three or four years of age, tem- porary 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 its way, although the pupil reflex is active, and a strong light may still be distressing. There are no ophthalmoscopic appearances. * Klin. Monatsbldtter f. Augenheilkunde, 1869, p. -465. PHLYCTENULAR OPHTHALMIA. 127 This blindness passes away completely in from two to four weeks. It has been regarded as a reflex phenomenon, and again it has been held to be due to disturbance of the intraocular cir- culation from pressure of the eyelids on the eyeball. But the view (Leber-Uhthoff ) which represents it as having a central cause is probably the correct one. It is likely, at this tender age, when the psycho-physical processes are not as yet firmly established, that the desire not to see, and the active withdrawal from the act of vision, leads in a short time to a functional paralysis of the visual centres in the brain ; and that these take some time to recover, or to re-learn their functions, when the ground for the suspension of the latter has ceased. Fig. 5G, IV Cause. — This is a disease of childhood, although it is rare in the very first year of life. In adults it is very uncommon. The strumous constitution, as indicated by the swollen nose and upper lip, and sometimes by the enlarged lymphatics in the neck, as well as by the eczema just mentioned, 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 allied irregularity of nutrition, of of which the great tendency to recurrence of the eye affection is evidence. Colonies of straw-colored micrococci may be found in the 128 DISEASES OF THE EYE. contents of the phlyctenulte ; but what etiological relationship to the production of the plilyctenuhc they possess is not yet known. Treatment — The solitary phlyctenula is best treated with the yellow oxide of mercury ointment * (commonly known asPagen- stecher's ointment), of which the size of a hemp-seed should be put into the eye once a day. Or, a small quantity of pure calo- mel dusted 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. The miliary phlyctenular conjunctivitis is best treated at first with cold or iced applications. Freshly prepared chlorine water ( 1 part Liq. Chlori., 9 parts water), to be dropped into the eye once a day, is recommended by some, and later on Liq. plumbi dil. or Sol. argent, nitr. (grs. v ad 5J, and neutralized) applied to the everted conjunctiva ; or, if the phlyctenular appearances predominate over the catarrhal, the yellow oxide of mercury ointment, or insufflations of calomel, may be preferred. I my- self rarely employ any remedy other than the two latter, which I find applicable to all these cases. When the cornea is slightly affected near the margin, in cases of miliary phlyctenuke, calomel, or Pagenstecher's ointment, and warm fomentations should be used. When a large pustule on the margin of the cornea has resulted in a deep ulcer, with tendency to perforate, and accompanied by much pain, I cannot too highly recommend paracentesis of the anterior chamber through the floor of the ulcer, the pupil having first been brought well under the influence of eserine, to pre- vent prolapse of the iris. The good effect of this will be very soon apparent: the pain disappears, the patient sleeps, the * R .-^Hydrarg. Perox. Proecip., gr. xxx. Vaselin, 5J. — M. Note. — Hyd. Perox. Pra'cip. is prepared by precipitating the Bichlo- ride of Mercury with Liq. Sodce, and washing the resulting oxide. I learn from Mr. Jabez Hogg that this ointment was in use by the late Mr. Guthrie, in the year 1849. PHLYCTENULAR OPHTHALMIA. 129 ulcer becomes vasoularized, and healing sets in. Cauterization of the ulcer in an early stage with the galvano-cautery is also good practice ; but in these cases I prefer the paracentesis. Many surgeons trust very much to eserine, warm fomentations, and a pressure bandage. For the fascicular keratitis the yellow oxide of mercury oint- ment is in its place. When the crescentic infiltration is very intense, it is well to touch it with the galvano-cautery. Division of the leash of vessels at the margin of the cornea has a bene- ficial effect. For the ring ulcer, a pressure bandage, under which an anti- septic dressing (boracic or salicylic acid, or perchloride of mer- cury) 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 phlyctenule of the cornea in the form of the minute gray 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 commenced, calomel, or weak yellow oxide of mer- cury ointment, may be employed. For the large purulent phlyctenula, 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° F., for twenty minutes three times a day), atropine, iodoform as ointment or powder, and a protection bandage, form the treat- ment in the early stages. Here, also, I often puncture the ulcer, with the very best results in respect of hastening the cure, and the galvano-cautery may be used with advantage. In the stage of reparation, Pagenstecher's ointment, or insufflations of calomel, are very useful. In all forms of phlyctenular ophthalmia, those favorite reme- dies, blisters, setons, and leeching, should be avoided. The first two worry the patient, give rize to eczema of the skin, and are not to be compared in their power of cure with the measures above recommended ; while leeching gives, at best, but tempo- 130 DISEASES OF THE EYE. rary relief, and deprives the patient of blood which he much requires. For relief of the blepharospasm, in addition to the use of atropine, plunging the child's face into a basin of cold water, and keeping it under until he struggles for breath, and this immersion repeated two or three times in rapid succession, and used every day if necessary, is a most efficacious means. It should always be used where the blepharospasm is severe, as this is not only distressing to the patient, but also an obstacle to the cure. The general treatment, notwithstanding the so-called photo- phobia, should consist in open-air exercise before everything else ; unless, indeed, there be an ulcer which threatens to perfo- rate. It is not well to keep the patient's face or eyes covered with bandages and shades. A pair of dark-blue glasses are the best protection from strong glare of light ; and shaded 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, syr. phosph. 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 to con- tinue 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 treatment will also assist in clearing up opacities, as best they may be. For this after- course of treatment calomel insufflations should be used. 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 the 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 (see Chap. VIII). PHLYCTENULAR OPHTHALMIA. 131 The degree of the defect of visioD to which an opacity of the cornea may give rise depends, in the first instance, on the posi- tion of the opacity. If it be peripheral, the vision may be per- fect ; 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 produce a proportionately greater defect. If a central, but not deep, ulcer should not be- come completely filled up in healing, and a facet remain, vision will also suffer much in consequence of irregular refraction, although there may be but little opacity. CHAPTER VI. DISEASES OP THE EYELIDS. Erythema, erysipelas, phlegmonous inflammation, and ab- scess are all liable to attack the eyelids, but require no special observations in this work. It should merely be stated that erysipelas of the eyelids may extend to the connective tissue of the orbit, and ultimately give rise to atrophy of the optic nerve. Eczema. — This is very often seen on the eyelids, most fre- quently in connection either with eczema of the face in general or with phlyctenular ophthalmia, which latter is to be regarded as eczema of the conjunctiva and cornea. The lachrymation in phlyctenular ophthalmia increases the eczema, which then, by causing contraction of the skin of the lower lid, produces ever- sion of the inferior punctum lachrymale, and this, in its turn, causes increased lachrymation, and thus a vicious circle is set up. Atropine infiltration of the eyelid, from long use of solution of atropine in some persons, is often accompanied by a moist form of eczema of the lids and face. Treatment should consist in the daily removal of the scabs, in such a way as to cause no bleeding of the surface underneath ; and, for this purpose, a warm solution of bicarbonate of potash is useful. The place should afterward be well dried, and painted with a strong solution of nitrate of silver (gr. xx ad 5J) and a boracic acid ointment (gr. xxx ad 5J), or the following, applied over this: 01. Cadin, n^xv; Flor. Zinci, gr. xx ; Lanolin, .^ij. — M. If the inferior lachrymal punctum be everted, the canaliculus should be slit up. Herpes Zoster ophthalmicus is an herpetic eruption, which affects the region supplied by the supraorbital division of the 132 THE EYELIDS. 133 fifth nerve of one side, and sometimes its nasal branch, and, in rare instances, the infraorbital division of the same nerve. The occurrence of the eruption is preceded, for some days, by severe neuralgic pain and swelling, with redness of the part. The number of vesicles varies much, and may be but three or four, or so numerous as to become confluent. As soon as the eruption appears, the pain usually becomes much diminished, and, indeed, often disappears. Vesicles are liable to form on the cornea, and these may result in ulcers, which, on healing, leave opacities. Iritis has also been observed as a complication, and even cyclitis, resulting in loss of the eye. The vesicles on the skin soon become purulent and gradually turn into scabs, which fall oflT and leave deeply pitted scars, recognizable during the remainder of life. The affection never crosses the middle line of the fore- head. Some neuralgia, with anaesthesia of the skin, may remain for a long time afterward. Inflammation of the Gasserian ganglion, with extension of the inflammatory process down the nerve, was found (O. Wyss) in the only case in which a 7905^ mortem examination has been made durinor the acute stacre of the disease. The afl?ection is most common in elderly people, but I have seen it, also, in young and healthy individuals. The Treatment can only be expectant, or, at most, directed to relief of the patient's suffering, by means of hypodermic injec- tions of morphia and other sedatives, and by emollients applied locally. Complications in the cornea and iris are to be dealt with on the principles laid down in the chapters on the diseases of those organs. Primary Syphilitic Sores occur on the eyelids, usually near the margin of the upper or lower lid, or at the inner or outer canthus. The first appearance is generally a " pimple," which ulcerates and becomes characteristically indurated about its base. The margin of the ulcer is clean-cut, and its floor somewhat excavated and covered with a scanty grayish secre- tion. Occasionally there is no ulcer present, but the entire lid is swollen, greatly indurated, purple, and shiny ; and then the 134 DISEASES OF THE EYE. diagnosis may be rendered difficult. The prseauricular and submaxillary 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. 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 dirty finger. Treatment. — Locally, sublimed calomel by Kane's method, dusting with finely powdered iodide of mercury, or the black wash may be used ; while the usual general mercurial treatment is employed. Secondary Syphilis gives rise to ulcers on the margins of the lids, to loss of the eyelashes (madarosis), and to the secondary skin afl^ections which attend it in other parts of the body. Vaccine Vesicles on the eyelids are produced by accidental inoculation at the intermarginal part of the lid; or on the outer surface of the lid, if the skin be abraded by the finger- nail, or otherwise. Sometimes the vesicle develops into a large ulcer with yellowish floor and hard and elevated 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 3J) is the best application. Rodent Ulcer (Jacob's Ulcer). — This disease commences as a small pimple or wart on the skin near the inner canthus, or over the lachrymal 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 indurated margin, the skin surrounding the dis- eased place being healthy and continuing so to the end of the chapter. The progress of the disease is extremely slow, extend- THE EYELIDS. 135 ing 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 afiTords the best chance of relief for the patient. Recurrence of the growth is the rule, but this should not deter from operative measures, nor even from the renewal of them, as they aflford much comfort to the patient and prolong his life. Even in advanced stages operation is frequently called for. The application of chloride of zinc or of the actual cautery should be employed, after the disease has been as thoroughly removed with the knife as is possible. My friend, Dr. C. E. Fitzgerald, informs me that he has had some remarkably good results in cases of rodent ulcer from the use of Bergeon's treatment. This consists in the internal ad- ministration of five grains of chlorate of potash three times a day, with the local application of a saturated solution of chlo- rate of potash to the ulcer. Marginal Blepharitis ([iAi(fap *Von Graefe's Archiv, xxxvi, 1, p. 234. THE EYELIDS. 145 were due, in his opinion, to primary atrophy of the levator pal- pebrse muscles. 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. Congenital ptosis is generally present in both eyes. It is due, in some cases, to an imperfect development of the levator pal- pebrse ; and, in others, to an abnormal insertion of this muscle, its tendon being attached to the tarsus too far back. Either Pageustecher's or Panas' operation may be employed here. Eversbusch has proposed* the following proceeding more particu- larly for congenital ptosis : — EversbuscKs Operation for Congenital Ptosis. — The object of the operation is to increase the power of the levator by ad- vancing its insertion, or rather by doubling it down over the tarsus where it forms fresh adhesions. Snellen's lid clamp is applied, so that the plate is passed well 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-way between this margin and the eyebrow. The skin and the subjacent muscle are then separated up, both upward and downward, 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 2* mm. of the tendon may be included in the suture. Each needle is now passed vertically downward between the tarsus and orbicularis, and brought out at the free margin of the lid at a distance from each other of about 2 2 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 *Monatshl.f. Augeiihk., 1883, p. 100. 13 146 DISEASES OF THE EYE. then the three sutures are closed tightly. It is desirable to slip glass beads over the ends of the sutures before tying thera, to prevent cutting into the margin of the lid. Both eyes are ban- daged, and the sutures left in for a week or more. Figs. 59 and 60 serve to render the foregoing explanation more lucid. Con- genital ptosis is sometimes associated with epicanthus. (See end of this chapter.) A remarkable condition is Congenital Ptosis with Associated Movements of the Affected Eyelid during the action of certain mus- FiG. 59. Fig. 60. /, levator palpebrte ; o, orbicularis. cles. There are only about fifteen cases of this on record. They all agree in this particular, that the upper lid affected with ptosis — most commonly the left lid — is raised when the mouth is opened. A synchronous contraction 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. It is probable that in these cases the levator is not wholly supplied by the third nerve, but partly also by nerve fibres which take THE EYELIDS. 147 their origin in the nucleus of the fifth pair, and which also supply the external pterygoid and digastric muscles. Needless to say, no remedy can be applied for relief of this condition. The term " ptosis" is also given, although not very correctly, to cases in which increased weight of the lid causes it to droop, as in conjunctival aflfections, or where a tumor has formed in the eyelid, or where there is a hyper-development of the subcutane- ous fat. Lagophthalmos (/.ay 6^, a /lare, as it was supposed that this animal sleeps with its eyes open ; oov, a tree) Keratitis. — This is a rare affec- tion, to which attention was first drawn by Hansen Grut, of Copenhagen. It is a very superficial and chronic ulceration, with but little infiltration of its margins or floor, and presenting the appearance of a fine groove on the cornea. It spreads, chiefly over the central region of the cornea, by throwing out THE CORNEA. 205 branches on either side. The pain and irritation is sometimes severe, and again but slight or quite wanting. Some permanent opacity often remains when cure has been effected. The Cause has not been definitely ascertained, but the peculiar progress of the affection renders it almost certain that some special fungus is engaged. Treatment. — Scraping with a sharp spoon, with the subsequent application of 1 in 1000 solution of corrosive sublimate to the cornea, is recommended by some, and the actual cautery is of great use. But I am inclined to think, from my experience with the last few cases of the disease I have had under my care, that the application of absolute alcohol affords the most certain and rapid cure. I soak a bit of lint in the alcohol and scrub the surface of the cornea with it. This may require to be repeated two or three times. (6) NON-ULCERATIVE INFLAMMATIONS OF THE CORNEA. — Abscess. — This affection is on the border-land between the ulcerative and non-ulcerative inflammations of the cornea ; for in one case it will result in an ulcer — usually the ulcus serpens — while again it will run 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 — fibrilla? and fixed cor- puscles — 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 gray 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 206 DISEASES OF THE EYE. also lose its brilliancy, although in a much less degree. Hy- popyon 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. Occasionally, a corneal abscess will be attended by but little pain or other irritation. Progress. — The abscess spreads through the cornea, usually in some one direction ; and this direction is indicated by the yel- lowish opacity being more intense at the advancing side of the abscess. Before long, if the abscess be superficial, the layers of cornea covering it come away, and the condition is changed into that of the ulcus serpens, already described. The deeper abscesses spread through the cornea more or less widely, and ultimately become absorbed, without having caused ulceration. But even these abscesses leave considerable opacity behind. Of the two, the process which ends in ulceration is the more common. 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 present on the foreign body which pro- duced the injury, or they may have been present in the con- junctival sac. Infection through the blood is occasionally seen in some acute exanthematous diseases, such as scarlatina, mea- sles, and smallpox ; more especially in the latter, in its con- valescent stage. Treatment. — Atropine, warm fomentations, and a bandage. But, if these mild measures do not in a day or so arrest the progress of the abscess, resort must be had to the actual cautery. Diffuse Interstitial, or Parenchymatous, Keratitis. — This affection occurs, most commonly, between the ages of five and fifteen. It commences at some one part of the margin as a light grayish opacity, accompanied with slight injection of the ciliary vessels. The rest of the corneal margin soon becomes THE CORNEA. 207 similarly affected ; and then, gradually, the opacity extends con- centrically into the cornea, or does so by sending in processes which afterward become confluent. In this way the whole cornea becomes affected by degrees ; and its epithelium acquires the breathed-on, or ground-glass appearance, which is seen, also, in acute glaucoma. The opacity lies in the deep layers of the true cornea, and is slightly more intense in spots here and there. It is sometimes only a very light cloud, while again the cornea may be so opaque as to render the iris quite invisible. When the whole cornea has become opaque, it begins to clear up at the margin, and the central portion becomes even more opaque than the margin had ever been ; a fact which shows that the very cells which entered the cornea at its margin have advanced to its centre. The clear margin gradually increases 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 impairment of vision may remain. Occasionally, the opacity commences in the centre of the cornea, and the margin remains clear all through. Again, a very intense vascularization (the so- called " salmon patch ") may gradually occupy the whole cornea, following the progress of the opacity. There is no tendency to ulceration in this affection of the deep layers. The affection is often accompanied by a good deal of pain and blepharospasm, especially in the vascular forms. It is very liable to be complicated with iritis, or even with iridocyclitis, and herein lies its greatest danger. The iritis is usually of the serous 'form, but may be plastic, and opacities in the vitreous humor often result from it. Exudative choroiditis and optic neuritis, also, very occasionally com- plicate it. The tension of the eyeball in these cases may be much diminished for a time. 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, and in one case which I saw the opacity did not begin to clear away for eleven mouths after the cornea was first 208 DISEASES OF THE EYE. attacked, the whole process extending over a period of two years. Both eyes invariably become affected, although not always at the same time, the second eye often not becoming attacked until the inflammation in the first has made some progress, or, perhaps, not until it has undergone cure. It is important to acquaint the patient, or his parents, with the likelihood of this course of events in the very commencement of his treatment. Diffuse interstital keratitis occurs also in adults, but I have never seen it in persons of over thirty or thirty-five years of age. These adult cases present a greater variety of type than those in children, and, on the whole, they are less severe in character. Most commonly, one eye alone becomes diseased, the degree of opacity is often slight, the extent of diseased cornea limited, the duration of the process compara- tively short, and the complete clearing-up relatively frequent. 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 over fifty per cent, of the cases, is inherited syphilis, a fact which was first pointed out by Mr. Jonathan Hutchinson. The children are generally thin, anaemic, and of stunted growth; with flat nose, cicatrices at the angles of the mouth, often more or less deaf, and the peculiarities of the incisor teeth, so well known from Mr. Hutchinson's description, are present in about one-half of the cases. 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. Prognosis. — In children, in view of the possibility of an incomplete clearing of the cornea and the irregularity of its surface which the process may cause, as well as of the serious complications liable to supervene and which may completely THE CORNEA. 209 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 very favorable prognosis may be given. I have never seen the affection recur, but it is said to do so very rarely. In adults, as stated, the prognosis is much more favorable. Treatment. — In the early stages no irritants should be locally applied. Atropine is important for the prevention of iritis or of posterior synechise ; and the use of warm moisture, in the form of poultices or fomentations, promotes vascu- larization and hastens absorption of the cellular elements, which form the opacity. When the acute stage is ended, the yellow precipitate ointment may be employed with benefit for stimulating the absorbents to carry off the remains of the opacity. Massage may be used with advantage in both stages, to disperse the infiltration. In the severe cases I would advise a course of mercurial inunctions continued for several weeks, care being taken not to allow stomatitis to exceed very moderate bounds. In mild cases a tonic plan of treatment, with iodide of iron and cod-liver oil, is the most suitable. ' In adults, where it is desirable to use mercurial treatment, a good method is the hypodermic injection of perchloride of mercury, ^ to ^V g""- ^^^^ ^ ^^1- From this I have had satisfactory results, but mercurial inunctions also answer well and are less painful. Counter-irritation, in the form of blisters to the temples or a seton in the scalp, is extensively employed by some surgeons. I have never adopted this treatment, as I doubt its value, and am loath to add a worry to the troubles inseparable from so weari- some a disease. Keratitis Punctata is the name commonly given to a condi- tion which occurs in cyclitis, in irido-cyclitis, and in sympathetic ophthalmitis (Chap. X). It is never a primary disease of the cornea. It is due to the deposit of minute beads of lymph on the 18 210 DISEASES OF THE EYE. membrane of Descemet, which gives to the affected part of the cornea a finely dotted appearance. The lymph is usually found only on the lower quadrant of the cornea — because it gravitates to the lowest part of the anterior chamber — in a triangular space, of which the base is at the corneal margin, while its apex is directed toward the centre of the cornea. This triangular shape is the result of the motions of the eyeball, w4iich throw the lymph beads against the cornea. When the process which gives rise to this condition passes off rapidly, the cornea is restored to its normal state; but when the primary disease is chronic, the nutrition of the true cornea, in the triangular space corresponding to the deposit of lymph, is apt to be interfered with — by reason of degeneration of the endothelium of Descemet's membrane, which protects the cornea from the aqueous humor — so that it becomes intensely and per- manently opaque. Some authors do not use the term Keratitis punctata for the foregoing condition, but reserve it for some cases of inter- stitial keratitis which present a spotted or dotted appearance. Sclerotizing Opacity of the cornea sometimes complicates scleritis, affecting the cornea in the neighborhood 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, and is apt to remain as a permanent opacity, even when the scleritis undergoes cure. In such cases of sclero-keratitis, iritis is often present. Treatment. — Warm fomentations, massage, and the treatment of whatever diathesis (rheumatism, syphilis) may be taken as giving rise to the scleritis. Riband-like Keratitis (Transverse Calcareous Film of the Cornea; Calcareous Film of the Cornea). — This is an altera- tion which occurs chiefly in the cornese of eyes destroyed by severe intraocular processes, such as iridocyclitis, sympathetic ophthalmitis, glaucoma, etc. It occupies that transverse strip of the cornea which is uncovered in the commissure of the eye- lids during waking. It usually commences on the inner margin THE CORNEA. 211 of the cornea, but soon appears at the outer margin and advances from each direction toward the centre, where the two sections join. It presents the appearance of a grayish-brown opacity, with, in many, but not in all, cases, white calcareous deposits in and under the epithelium. Magnus* points out that in blind eyes which are constantly rolled upward the opacity is found, not in the cen- tral transverse section of the cornea, but in its lower third, and from this circumstance he argues that the chief factor for its production is exposure of the part affected. He believes, moreover, that so large a proportion of the affected eyes having suffered severely in their general nutrition indicates that the Fig. 86. (Pagenstecher.) Fig. 87. {Pagenstecher.) opacity is a further development of this malnutrition. He proposes for the affection the name Keratitis trophica. ECTASIES OF THE CORNEA. Staphyloma Corneae is the result of a perforating ulcer of the cornea. This, having healed, may present a weak cicatrix, which becomes bulged forward by even the normal intraocular tension (Figs. SQ and 87). If the iris be not involved in this cicatrix, the anterior chamber will be made deeper (Fig. 87). Staphyloma corneae, in which the iris is involved, is probably a more common condition than the above. * Klin. Monatshl.f. Augenheilkunde, February, 1883, p. 45. 212 DISEASES OF THE EYE. \yhen the ulcer is large, a correspondingly large portion of iris is liable to become prolapsed into it and to form a bulging mass outside the eye. 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 consolidated by the formation of a layer of con- nective tissue over it. 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 develops into an opaque cicatricial membrane. Should this not be strong, the normal intraocular tension is sufficient after a time to make it bulge ; or, increased intraocular tension may arise in consequence of further changes within the eye, and then bulging of the pseudo- cornea more surely comes on, and the condition is termed total staphyloma of the cornea. Sometimes a total staphyloma has a lobulated appearance, owing to the pseudo-cornea having some fibres stronger than others, and hence the name given to the condition, from (jza(fulri, a bunch of grapes. Such staphylomata are apt to gradually increase to a very large size. Treatment. — In cases of partial staphyloma, where a clear portion of the cornea remains, an iridectomy is frequently indi- cated 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. When, sight having been lost, the staphyloma is very bulging, or when total staphyloma is present, enucleation of the eyeball or one of the following opera- tive measures must be adopted. Abscission. — A Beer's cataract knife being passed through the base of the staphyloma, with its edge directed upward, the upper two-thirds of the staphyloma are separated ofi", while the remain- ing third is detached by means of a scissors. If the lens be present, it must now be removed. The wide opening becomes filled up'with granulations and cicatrizes over. THE CORNEA. 213 In de Wecker's* method the openiDg is closed with conjunc- tival sutures. He begins the operation by separating the con- junctiva all round the margin of the cornea, and then loosening it from the eyeball nearly as far back as its equator. Four sutures (a, b, c, d), of different colors, are then passed through the con- junctiva about 2 to 3 mm. from the margin of the wound, as represented in Fig. 88. In order to keep the field of operation clear, the ends of two of these sutures are laid over on the nose, Fig. 88. while the others are laid over on the temple. The staphyloma is now abscised, and the sutures drawn together and tied. The conjunctival scar, de Wecker states, can be tattooed in the centre at a later period, and by this means the wearing of an artificial eye made unnecessary. The late Mr. G. Critchett proposed the following method, which has met with much approval : The base of the staphy- loma is transfixed with four or five curved needles passed from above downward at regular intervals (Fig. 89), the punctures Chirurgie Oculaire, p. 188. 214 DISEASES OF THE EYE. 'J}'])]) and counter-punctures being in the sclerotic, at points half-way between the margin of the sta- phyloma and the insertion of the recti muscles. With a sharp knife the staphyloma is now divided horizontally, the inci- sion running from the inser- tion of the external rectus to that of the internal rectus ; and then the two halves of the sta- phyloma are abscised with scis- sors, the line of abscission lying some 2 mm. from the points of entrance and exit of the needles. The latter are now drawn through and the sutures tied, so that the edges of the sclerotic may be applied to each other as accurately as possible. The resulting stump (Fig. 90) is capable of carrying an artificial eye without becoming irritated. The foregoing and other methods of abscission are only appli- cable where the tension is either low or normal. If it be high, the liability to intraocular hemorrhage during the operation makes enucleation, evisceration, or Mules' operation, more suitable proceedings. Indeed, I, and probably most surgeons, would now employ one of the two latter operations in all these cases. Evisceration (Exentera- tion) was proposed about the same time by Professor Graefe, of Halle*, to prevent death from meningitis after the removal of suppurating globes, and by Mr. Mules,! of Manchester, chiefly to take the place of enuclea- FiG. 90. 'n))M)?i' * Centralblf. Augenheilk., 1884, p. 378. t^bid., 1885,[p. 32. THE CORNEA. 215 tion in cases of sympathetic ophthalmitis. There are some who are opposed to its employment in those cases ; but, for staphy- loma of the cornea, it cannot meet with any such opposition. The cornea is reaioved by making an incision with a Graefe's knife, so as to include one-half of the corneo-scleral margin, and then completing the circumcision with scissors. All the con- tents of the globe are then evacuated by means of Mr. Mules' scoop, care being taken to remove the choroid unbroken by carefully peeling it from the sclerotic margin backward, until it is only held at the lamina cribrosa. The scoop is then used to lift the separated unbroken choroid and its other contents out of the globe. Finally, the margins of the sclerotico-conjunctival wound are drawn together with a few points of suture. The whole proceeding should be done with strict antiseptic precautions, chief among which is the free use of irrigation with a 1 in 5000 solution of corrosive sublimate before, duriug, and after the operation, the interior of the globe being most carefully washed out with the solution in a full stream. The result is a good and freely movable stump for the application of an artificial eye. Mules' Operation. — This proceeding, a modification of the foregoing, was also proposed by Mr. Mules* for cases of threatened sympathetic ophthalmitis, and, like simple eviscera- tion, has not yet met with universal acceptance in those cases. Its object is to provide a still better stump for the artificial eye by the insertion into the scleral cavity of a hollow glass ball, called an "Artificial Vitreous Humor." It is performed as follows : — The cornea is removed — the conjunctiva having first been freed from the scleral edge toward the equator of the eye- ball — 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 * Trans. Ophthal Soc, Vol. v, p. 200. 216 DISEASES OF THE EYE. introduction is best effected by means of a special instrument designed for the purpose by Mr. Mules. The spheres are made* in several sizes to suit different cases, and it is well not to use the largest which will fit into any given eye. The margins of the sclerotic opening are now united vertically by some points of interrupted suture, for which purpose I prefer silk to catgut, as the latter is apt to undergo absorption before complete union has taken place. The conjunctival opening is then closed by another set of sutures placed at right angles to the sclerotic line of closure. Similar antiseptic precau- tions are required, as in simple evisceration, and care must be taken that all bleeding in the cavity has ceased before the glass sphere is inserted. Before the lids are closed, the anterior surface of the globe is well covered with powdered iodoform. A firm antiseptic bandage is applied. I do not dress the eye for forty-eight hours, and after that once every twenty-four hours, using the corrosive sublimate solution freely and iodoform. There is generally some reaction, consisting of chemosis, swelling of the eyelids, and pain, and sometimes these symp- toms are very marked, especially if rather 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. To prevent excessive reaction, Mr. Mules burrows into the orbit at the outer side, so that the points of the scissors may penetrate well beyond the back of the globe, and then intro- duces deeply a drain of gold wire, such as is used by dentists bringing it out between the lids at the outer canthus. An ice-bag is applied. The drain is left in about three days. The danger that the glass sphere may get broken by a blow upon the eye has been put forward as an objection to this method. No doubt it is an accident which may occur, and would then necessitate the enucleation of the eye ; but no case of the kind has as yet been recorded, although the operation has been in use for seven years. Silver spheres, instead of those * By Messrs. Armstrong, of Deansgate, Manchester. THE CORNEA. 217 of glass, have been sometimes employed to obviate the danger referred to. I practice this method a great deal, and I can heartily recommend it. The only trouble I have had with it is, that sometimes the sclerotic opening does not close well, and the glass ball has to be removed. The case then becomes one of simple evisceration. Conical Cornea, or Keratoconus. — In this the cornea is altered in shape to that of a cone. The change is due to a gradual and slowly advancing atrophic process in the cornea, especially at its centre, in consequence of which the normal intraocular tension acts on it, so as to distort it into the form represented in Fig. 91. The cornea remains clear, except sometimes just at the apex of the cone, where a slight nebula may be present. The condition is easy of diagnosis in its ad- vanced stages by mere inspection of the cornea, especially in profile, but in its commencement it may not be so. In the early stages, when the light is thrown on the cornea from the oph- thalmoscope mirror, as in retinoscopy, the corneal reflex will be noticed to be smaller at the centre, owing to the greater curvature there. Moreover, a dark shadow, circular or cres- centic in shape according to the incidence of the light, will be seen between the corneal margin and centre ; and, finally, when the fundus is examined its details will be seen distorted. 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. Treatment. — In the early stages, or in slight cases, an im- provement in vision may be obtained by means of concave spherical, or sphero-cylindrical glasses; for, as is evident, the change in shape of the cornea must cause the eye to 19 218 DISEASES OF THE EYE. become myopic. At a later period these glasses are of little use. Hyperbolic lenses have been employed, but although they may raise the acuteness of vision, there are obvious difficulties in the way of the practical every-day use of them. A stenopseic slit renders assistance in some cases. A few cases are reported in which the keratoconus was much reduced, and vision greatly bettered, by installations of eseriue and the application of a pressure bandage continued for several months. But it is upon operative measures we must chiefly rely in this affection for any improvement in sight. Von Graefe's Method consists in flattening the cornea by the production of an ulcer on the apex of the cone, and the resulting cicatricial contraction. From the surface of the cornea, a little to one side of the apex of the cone, a morsel of corneal substance is removed with a cataract knife, care being taken not to open the anterior chamber. On the second day after this proceeding the wound is touched with mitigated lapis (solid), and this is repeated every third day for a fort- night or three weeks. Paracentesis of the anterior chamber is then performed through the floor of the ulcer, and the aqueous humor is evacuated every second day for a week, after which the healing process is allowed to take its course. A bandage must be worn during the whole course of the treat- ment. Finally, when the contraction and subsequent flattening are completed, a narrow iridectomy may be necessary, in consequence of the central, or almost central, and rather intense corneal opacity. In Bader's Method a small elliptical flap of the cornea at its apex is removed, and the margins are brought together by one or two fine sutures. The sutures are omitted by many surgeons as useless and as liable to cause irritation. Opinion is divided as to whether the ellipse should lie vertically or horizontally in the cornea. Anterior synechia takes place in a large number of the cases, and a subsequent optical iridectomy is always required. I have myself no experience of this THE CORNEA. 219 operatioD, but it is said to be attended with unusual risk of suppuration of the cornea, going on to destruction of sight. Sir William Bowman's Method consisted in cutting a disc on the apex of the cornea with a small trephine, and then severing this disc with forceps and cataract knife. Cicatriza- tion of the wound produces the desired flattening of the cone. Septic infection is here also a danger, although it has not come under my own observation. I have myself, in one case, employed the electro-cautery to produce the desired loss of substance on the apex of the cone, but I am not as yet in a position to speak of the ultimate result. I believe that others have used the electro- cautery with good result for sight. The proceeding is free from all risk of septic infection. With the same object some surgeons have had recourse to Multiple Puucturings of the apex of the cone with a fine cataract needle. The summit of the cone is transfixed from three to six times at each sitting, and this may be repeated at intervals of two weeks or more. The first effect of the punctures is to allow some of the aqueous humor to escape, and then the eye is firmly supported with a bandage. The pupil is kept under the influence of eserine. Eventually, a network of cicatrical tissue forms, which flattens the cone with- out giving rise to much corneal opacity. Tumors of the Cornea. Primary tumors of the cornea are extremely rare. Epi- thelioma and sarcoma have their origin, not in the cornea, but in the limbus conjunctivae (p. 119). Dermoid tumors are usually seated partly on the conjunctiva and partly on the cornea (p. 119). Yet a very few cases of epithelioma and of fibroma are recorded as taking their origin in the cornea. Injuries of the Cornea. Foreign Bodies in the Cornea, such as morsels of iron, stone, coal, etc., are among the most common accidents of the entire 220 DISEASES OF THE EYE. body. The pain caused by these foreign bodies is very consider- able, as may be imagined when the rich nervous supply of the cornea is remembered. The dangers which may follow on the presence of a foreign body in the cornea, depend partly upon the infection or non-in- fection of the foreign body, and partly upon the depth at which it is 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 its removal. A foreign body which carries infection upon it, 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 all suspicion on this point at rest. Many foreign bodies are so small as to defy detection, until the cornea is searched with the oblique light, an aid which should always be made use of, whenever the symptoms or history in the remotest way suggest the presence of a foreign body. A foreign body which lies only in the epithelium, or in the superficial layers of the cornea, is easily removed. The eye having been thoroughly cocainized, the patient is seated, and leans his head against the chest of the surgeon, who stands be- hind him. 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 upward and backward, while with the second finger he depresses the lower lid in a similar manner, and between these two fingers he can, to a great extent, restrain the motions of the eyeball. The foreign body is now to be 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. Care must be taken not to infect the cornea in the removal of a foreign body, and consequently thorough antiseptic pre- THE CORNEA. 221 cautions must be taken. After the foreign body is removed the place where it was seated should be washed with a 1 in 5000 solution of corrosive sublimate. A bandage is worn until the epithelium is regenerated — i.e. for several days. Every surgeon and general practitioner should possess the two small instruments required for the removal of superficial corneal foreign bodies, and should understand the use of them. The magnet is of no use whatever 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 so long as to protrude somewhat into the anterior chamber, and there is danger that in the attempts at removal it may be pushed further on, and fall into the anterior chamber. Here 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 forward. Simple Traumatic Losses of Substance 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. These injuries heal readily by protecting the eye with a bandage ; but when neglected, or if septic matter have been introduced when the injury occurred, or if it be present in the conjunctiva or lachrymal sac, these losses of substance are capable of forming the starting-point of corneal abscess, ulcus serpens, etc. Opacities of the Cornea. Nebula, Macula, Leucoma. — These terras are applied to opac- ities in the cornea, of varying degrees, the result of some diseased process, or consequent upon an injury. The first term is used for very slight opacities, often discoverable only with oblique illumination. Macula indicates a more intense opacity, recog- nizable by daylight. Leucoma is a completely non-translucent and intensely white opacity, the result always of an ulcer, which 222 DISEASES OF THE EYE. 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 through the cornea. In these latter cases the iris may have become adherent in the corneal cicatrix, and then the term leu- coma adhnerens is employed. Very often, eyes with a nebulous condition of the cornea of old standing are myopic. It is probable that this myopia is pro- duced by the habitual close approximation of objects to the eye, owing to the diminished acuteness of vision from the opacity of the cornea. Treatment. — Little or nothing can be done to reduce these opacities. In slight and fresh cases, massage may render them less intense. In nebulous cornea a stenopseic apparatus often improves the sight. This consists of a metal plate with a small central hole or slit, which is placed before the patient's eye in a spectacle frame. By this arrangement a large portion of the rays which pass through irregular parts of the cornea, and which merely confuse the sight, is cut off. Where myopia is present the suit- able concave glasses for distant vision should be prescribed. The Operation of Tattooinrj was first proposed by de Wecker, and is a valuable proceeding for improvement of the appearance of the eye in cases of leucoma. But it is also an extremely useful method for the improvement of the sight in certain cases of nebula of the cornea, where the nebula occupies only part of the pupillary area of the cornea. In these cases much disturbance of sight is caused by the dis- persion of the light which makes its way through the nebula ; and when, by tattooing the scar, all light is prevented from get- ting through, brighter and distincter vision is enjoyed with the part of the cornea opposite the pupil, which is absolutely clear. In the case of a leucoma, either the whole surface of the leucoma may be tattooed, or only part of it, e.g., its centre, in order to represent a pupil. The material used is fine India ink, rubbed into a very thin paste. The eye having been cocainized, the leucoma is THE CORNEA. 223 spread over with this paste, and then covered with innumer- able punctures by means of de Wecker's multiple tattooing- needle, each stab of which carries into the corneal tissue some of the black pigment. The coloration continues suffi- ciently intense for some months, but then often begins to get pale, owing, probably, to the pigment falling out of the punctures. A better method of tattooing, by which the pig- mentation lasts longer, is performed with de Wicker's single grooved needle. The pigment is placed in the groove of the instrument, which is then passed into the true cornea, a long canal being made in a plane parallel to its surface. On withdrawal of the needle the pigment remains behind. A large number of such canals must be made in close proximity to each other, until the desired intensity of color is obtained. In cases where the whole cornea is leucomatous, and, con- sequently, where no restoration of sight can be obtained by means of an artificial pupil, Transplantation of a Portion of Clear Cornea from a rabbit's eye, or from a freshly enucleated human eye, has been repeatedly performed by ophthalmolo- gists in various parts of the world. Very many of these operations have been perfectly successful in a surgical sense, i. e., in so far as the healing-in of the transplanted flap is con- cerned ; but, with two exceptions, they all ended in disap- pointment, in consequence of the flap not retaining its trans- parency. In the course of a week or two the transplanted portion invariably became as opaque as the leucoma had been before. The mode of proceeding consisted in removing a portion of the leucoma with a trephine, and then, with the same instrument, cutting a disc out of the clear cornea to be utilized, and inserting it into the opening in the leucoma. Various theories were formed to account for the occurrence of the opacity in the transplanted flap, but into all of these it is unnecessary to enter. Von Hippel* came to the conclu- sion that the onset of the opacity was due to the entrance of the aqueous humor into the substance of the cornea, *Bericht der Ophthal. Gesellschaft zu Heidelberg, 1886, p. 54. 224 DISEASES OF THE EYE. owing to the solution of continuity in its posterior epithelium ; Leber's experiments* having shown that, unless this epithe- lial layer be intact, the transparency of the cornea cannot be maintained. Von Hippel, acting on this theory, applied a trephine to the leucoma as deep as the posterior elastic lamina, and then dissected off the superficial layers contained within the ring, leaving only the posterior elastic lamina and posterior epithelium. With the same trephine he then excised a disc of its entire thickness from a rabbit's cornea, and applied it to the wound. Iodoform was dusted over this and a bandage applied. Healing took place readily, and, twenty months afterward, the flap continued transparent, and vision = ^2_o_^ You Hippel has had some other successful cases. Sclerotizing Opacity of the cornea sometimes complicates scleritis, affecting the cornea in the neighborhood 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, and is apt to remain as a permanent opacity, even when the scleritis undergoes cure. In such cases of sclero- keratitis, iritis is often present. Treatment. — Warm fomentations, massage, and the treatment of whatever diathesis (rheumatism, syphilis) may be taken as giving rise to the condition. Arcus Senilis. — This is a change which is developed in the cornea without previous inflammation. It presents the appear- ance of a grayish line a little inside the margin of the cornea and all round it, most marked above and below, and never advancing further toward its centre. It is most common in elderly people, but 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 hyaline degeneration of the corneal cells and fibrillse, and is not a sclerosis, as is stated by some authors. * A von Graefe's Archiv, vol. xix, p. 87. CHAPTER IX. DISEASES OP THE SCLEROTIC. Inflammation of the sclerotic is not a common disease, although the diagnosis "scleritis" is often made by inex- perienced persons, every " redness of the white of the eye " being taken for inflammation of the sclerotic. Beginners are warned against this error. Iritis, cyclitis, and conjunctivitis, as well as scleritis, cause redness of the white of the eye. The diagnosis from conjunctivitis is easily made by ob- serving whether the conjunctival vessels can be moved over the afiected part or not ; while in iritis and cyclitis the ciliary injection is confined to the part immediately surrounding the cornea. Moreover, in iritis the appearances of the iris itself are conclusive ; and in scleritis, as will just now be seen, the appearances are characteristic. Scleritis attacks only that part of the sclerotic which is anterior to the equator of the eyeball, and 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 diflferent degrees of the same disease. But the necessity of admitting the exist- ence of two forms depends upon the different course they each take ; the superficial form being a relatively harmless disease, while the deep form entails serious consequences. Episcleritis appears as a circumscribed, purplish, rather than red, spot, 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 225 226 DISEASES OF THE EYE. node at the affected place, with pain, more or less pronounced and 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 circumference 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. But the patient should be made acquainted with the tedious nature of the affection. Very mild attacks of epi- scleritis will be met with, which pass away in a few days, and do not recur. Causes. — The affection is often of rheumatic origin ; it occurs sometimes in persons of scrofulous or syphilitic constitutions ; and it is more frequent in senior adults than in children or young people, and more commonly attacks women than men. Treatment. — No irritant should be applied to the eye. Local treatment should be confined to warm fomentations and protec- tion. 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, the rheumatic taint 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. Iodide of potas- sium and hypodermic injections of pilocarpine are useful remedies in some cases of this obstinate disease. Deep Seleritis. — Here the whole sclerotic is more likely to be affected at once than in the milder form ; although cases often enough occur where only an isolated node is present at a time. It is the progress of the case alone which can render the diagnosis certain, and hence the importance of a guarded prog- nosis in the early stages of every case of seleritis. In the deep DISEASES OF THE SCLEROTIC. 227 form, changes — thinDing and softening — of the scleral tissue take place, which render the latter less resistant, and, conse- quently, expose it to distention by even the normal intraocular tension. The result of this is a bulging (staphyloma) of the anterior part of the eyeball. This bulging in itself 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 sclero- tic affects only a portion, and not the whole, of its 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-gray appearance, due to the shining through the thinned sclerotic of the uveal tract. Either with or without such staphylomatous changes, sclerotiz- ing opacity of the cornea may come on, and iritis, choroiditis, and opacity of the vitreous humor are not uncommon complica- tions. Both eyes are usually affected. Cause. — Young adults are the most common subjects of deep scleritis, and females more often than males. Congenital syphi- lis, rheumatism, struma, and disturbances of menstruation are the most common assignable causes. Treatment. — There are few diseases less amenable to treat- ment. When any of the above causes can be assumed to be present, the suitable remedies are, of course, indicated. Besides this, warm fomentations, dry cupping on the temple, or the arti- ficial leech, complete rest of the eyes, and protection 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. 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 primary danger of a rupture or perforating wound of the sclerotic — apart from the loss of contents of the eyeball, which is 228 DISEASES OF THE EYE. often associated with it — consists in the possibility of infecting organisnas being introduced into the interior of the eye, and there setting up serious inflammatory reaction. A large and gaping wound is easily recognized. A portion of the choroid, ciliary body, or iris, according to the position of the wound, probably lies in it, or part of the vitreous humor may be found in it; while the vitreous humor, as seen through the pupil, will be found full of blood (hsemophthalmos), and blood may be present in the anterior chamber (hyphsema, '3-o, under) al/aa, blood), especially if the wound be far forward. Small wounds may be concealed by subconjunctival hemorrhage, and here re- duced tension of the eyeball is sometimes a valuable diagnostic sign. Clean-cut perforating wounds of the sclerotic often heal with- out inflammatory reaction, even when portions of the uveal tract, or vitreous humor, are prolapsed into it, these prolapsed parts becoming incarcerated in the cicatrix. Even irregular ruptures of the sclerotic from blows, with prolapse of uvea, and vitreous humor, and, as sometimes occurs, evacuation of the lens, may heal without inflammatory reaction. It may here be mentioned that these ruptures from blows almost always occur close to the corneal margin, and concentrically with it, and lie usually near its upper, or upper and inner, margin. And one often sees the conjunctiva remain intact over the rupture, with perhaps the lens dislocated under it. When inflammatory reaction follows upon one of these injuries, it may either be 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 may give rise to sympathetic ophthalmitis, a danger which is not associated with 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 seriousness of DISEASES OF THE SCLEROTIC. 229 the position is much aggravated ; but the discussion of this matter will be treated of in Chap. XIV, on Diseases of the Vit- reous Humor. Treatment. — In cases where the wound is small, no suture need be applied ; a bandage will be sufficient to promote the natural tendency to healing. But, where the wound is large and gaping, any prolapsed choroid, etc., should be first freely irrigated with sublimate lotion, 1 in 5000, and reduced as well as possible, and then the margins of the wound drawn together by a few points of suture in the sclerotic. A bandage is applied, and the patient kept quiet in bed. But if the injury be such — very wide wound, much loss of contents of the eyeball, or extensive intraocular hemorrhage — as to render restoration of useful sight beyond reasonable hope, it will be wiser to remove the eyeball at once, rather than run the risk of sympathetic ophthalmitis without compensating advantage. Tumors of the Sclerotic are almost unknown as primary growths, but fibroma, sarcoma, and osteoma have been so observed. CHAPTER X. DISEASES OP THE UVEAL TRACT. (Iris, Ciliary Body, and Choroid). If it be remembered that the iris, ciliary body, and choroid closely resemble each otherhistologically, that their blood supply is identical, and that they form with each other a continuous membrane, it is a matter of surprise to learn that any one of these three divisions of the uveal tract can undergo inflamma- tion, while the other two remain perfectly healthy. Yet this is, by no means uncommonly, the case. But it is, perhaps, more common for at least two of them, and especially the iris and ciliary body {irido-cyclitis), to be simultaneously inflamed ; and the entire tract may, of course, be affected at once. Clinically we cannot always know whether only one, or more than one, division of the uveal tract is in a state of inflammation, and this uncertainty of diagnosis is particularly liable to arise when there is severe acute iritis, for then the symptoms present might all be derived from the iritis alone. It may be taken for granted that in every rather severe case of iritis, particularly in those of syphilitic origin, more or less cyclitis is also present ; while a deep anterior chamber, or tenderness on pressure, increases the suspicion. In slight cases of iritis there will, probably, be no cyclitis. It is only after the acute inflammatory symptoms have sub- sided, and the pupil has become clear, that disseminated changes in the choroid, opacities in the vitreous humor, and even retinitis and optic neuritis, which may lead to optic atrophy, can be dis- covered, with their corresponding depreciation of vision. It is desirable, in a systematic consideration of inflammation of the uveal tract, to discuss it under the separate headings of 230 THE IRIS. 231 the iris, ciliary body, and choroid ; and the same remark applies to the other diseases and to the injuries of this tunic. Iritis. The most rational division of the different kinds of iritis is that founded on their pathology, namely :— (1) Simple Plastic Iritis; (2) Serous Iritis; and (3) Parenchymatous (including Purulent) Iritis. Their Common Characteristics, more or less marked, are : — Discoloration, loss of lustre and of distinctness of pattern, and functional disturbances (impaired mobility) of the iris, with contraction of the pupil. The loss of lustre and of distinctness of pattern is due to an alteration in the endothelium, which covers the surface of the iris, to the presence of lymph, and to cloudiness of the aqueous humor. The change in color is due to hypersemia of the iris, as well as to the presence of the inflam- matory products; a blue iris becomes greenish, a brown iris yellowish. The impaired mobility and the contracted pupil are due to the hypersemia, to spasm of the sphincter iridis, and to posterior synechise. Exudation of inflammatory products is present, in greater or less degree, in all these forms, and is found : (1) on either sur- face of the iris and in the pupil, in plastic iritis ; (2) in the aqueous humor and posterior surface of the cornea, in serous iritis ; (3) in the tissue of the iris, in parenchymatous iritis. Posterior synechise (o-avc'/ccv, to hind together), i. e., adhesions between the iris and the anterior capsule of the lens, occur as the result of inflammatory exudation on the posterior surface or on the pupillary margin of the iris. The presence of posterior synechise is ascertained by observing the motion 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 solu- tion on the pupil, the latter dilating only at those places where there are no synechias. If the entire pupillary margin have be- come adherent, the condition is termed complete posterior synechia, circular posterior synechia, ring synechia, or " exclu- 232 DISEASES OF THE EYE. sion " of the pupil ; and in such cases, if of some standing, atropine has no effect on the pupil. If the area of the pupil be filled with exudation, circular synechias being usually also present, the condition is known as " occlusion " of the pupil. Total posterior synechia is the condition in which the whole posterior surface of the iris is adherent to the capsule of the lens. In addition to the foregoing, circurocorneal injection of the ciliary vessels is a common symptom in most cases of iritis. The subjective symptoms in iritis consist, in the first place, of pain due to irritation of the ciliary nerves in the inflamed part. Yet this pain is not always referred to the eye itself, but often appears in the form of supra-orbital neuralgia, or affecting the infra-orbital division of the fifth nerve. Dimness of vision is the second subjective symptom of iritis. It may be due to cloudiness of the aqueous humor or cornea, or to exudation of lymph in the pupillary area on the anterior capsule of the lens, or, where the ciliary body is implicated, to opacities in the vitreous humor. Cases of iritis in which there has been no pain and no circumcorneal injection, and in which the failure of sight alone it is which brings the patient to the surgeon, are not uncommon. Examination then discovers the presence of extensive posterior synechise, which have probably been gradually forming for a long time back. These cases of " quiet iritis " belong to the plastic form, and are, in my experience, usually due to rheumatism {vide infra). A mistake into which beginners very often fall is to take a case of iritis to be conjunctivitis or scleritis (see p. 84), the " redness of the white of the eye " being what misleads. The condition of the iris itself will assist most in the diag- nosis. Moreover, the pain in iritis is of neuralgic character, but in conjunctivitis is similar to that caused by a foreign body in the conjunctival sac. In iritis there is no discharge, while in conjunctivitis the eyelids are gummed in the morning by muco-purulent discharge. Of course, iritis and conjunctivitis may occur together. THE IRIS. 233 Simple Plastic Iritis is the most common form. In it the circumcorneal injection is generally well marked, some- times causing elevation of the limbus of the conjunctiva, and even general, although slight, chemosis. In very mild cases, however, as also in chronic cases, the injection may be slight. The loss of lustre and of distinctness of pattern of the iris is well marked, and there is considerable change in the color of the iris. Posterior synechise are very apt to form. In some rare cases of plastic iritis, an enormous quantity of gelatinous exuda- tion is present in the anterior chamber. In Secondary Syphilis one often sees iritis, which, although doubtless due to the syphilitic taint, presents no clinical characteristic different from ordinary simple plastic iritis, yet it is probable that many of these cases are parenchymatous, or coudylomatous. Rheumatic Iritis is of the simple plastic form, but accom- panied by circumcorneal injection, which is great in proportion to the other signs of iritis present. The pain in rheumatic iritis is often peculiarly severe. Yet, as I have already stated, ** quiet iritis" is most often due to rheumatism. Gonorrhoeal Iritis is a mixture of the plastic and serous forms. It does not attend on, nor immediately follow, a gonor- rhcea ; but an attack of rheumatic arthritis, usually of the knees, always intervenes. Gonorrhoeal iritis is extremely rare. Serous Iritis. (Keratitis punctata. Aquocapsulitis Des- cemetitis.) — Here the exudation is mainly a serous fluid. From this fluid fibrinous elements, in the form of very fine yellowish spots, are precipitated on the posterior surface of the cornea, chiefly in its lower quadrant, and often in a triangular shape, the base of the triangle corresponding with the lower margin of the cornea, the apex being directed toward the centre of the cornea, and the finer dots near the apex. The triangular shape is a mechanical result of the motions of the eyeball. In cases where the corneal deposit continues for a length of time, owing to degeneration of the posterior epithelium, 20 234 DISEASES OF THE EYE. permanent secondary changes in the true cornea are pro- duced, and a consequent peculiar triangular opacity at the lower part of the cornea will ever afterward indicate the nature of the process which has gone before. In serous iritis the pupil is usually not contracted, and the circumcorneal injection is slight. The anterior chamber is often deep, owing to the quantity of fluid secreted, and the aqueous humor is cloudy. The increase in the contents of the anterior chamber frequently causes increase in the intraocular tension. Pure serous iritis is perhaps not so common as a mixed form of seroplastic iritis. But there is good reason to regard all these cases of keratitis punctata as due, not to inflammation of the iris, but to cyclitis. Parenchymatous (including Purulent) Iritis. — Here the in- flammatory product is situated in the tissue of the iris. The consequent swelling of the iris may be present over its whole extent, or may be confined to a circumscribed part of it. In the latter case the swelling is sometimes called a condy- loma. The color of the iris changes remarkably, at the affected part, to a yellowish or reddish-yellow hue, and new vessels are formed in it. In Syphilis, late in the secondary stage, a form of iritis occurs which may always be recognized as syphilitic. It is character- ized by the formation of circumscribed tumors, or small condy- lomata of a pale yellowish color, the rest of the iris being, apparently, intact. These tumors 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 tumor present, and there are seldom more than three or four. This form belongs to the parenchymatous class, and is by no means common. Yet many authors hold that in most, if not all, cases of syphilitic iritis, condylomatous tumors are present, but of such small size as to escape detection with our ordinary clinical methods. Symptoms of Iritis in General. — 1. Pain. This is situated not THE IRIS. 235 SO much in the eye as in the brow over it, in the corresponding side of the nose, and in the malar bone, and may even extend to the whole side of the head. It varies in its intensity; it is usually more severe at night, and is often called neu- ralgia by the patients. The simple plastic form is the one attended by the most severe pain, the serous form is gener- ally unattended by pain, while the parenchymatous form is often excessively painful, and again completely painless. 2. Lachrymation and photophobia are occasionally present, but never to such a degree as is often observed in certain corneal affections. 3. Dimness of vision. This is usually complained of as soon as the inflammation is pronounced. Cloudiness of the aqueous humor and keratitis punctata affect sight in proportion to their degree, and exudation in the pupil may reduce vision to a quantitative amount. The tension of the eye in iritis is usually normal, but in some cases of violent plastic, serous, and parenchymatous iritis the tension will be found high. Prognosis. — The length of duration of an attack of iritis cannot be foretold at the outset. Cases which are, in other respects, mild, i.e., where the pupil dilates well and rapidly to atropine, where the aqueous humor is clear, and where but little lymph is thrown out, often continue for weeks irritable and painful, with a marked tendency to relapse if treatment be at all relaxed. An attack of iritis may last from two to eight weeks, the plastic form being the most rapid and the serous form the slowest. Recurrences of the inflam- mation are common, owing to continuance of the constitu- tional taint which gave rise to the iritis in the first instance. It is possible that an attack of any form of iritis, if carefully treated from the beginning, may leave the eye in as healthy a condition as before ; but it is quite as common, in spite of every effort, to find posterior synechise, isolated or as a circular syne- chia, left behind. The presence of a few isolated synechise, if the pupil be clear, is in itself harmless to sight, but, if relapses take place and fresh adhesions be formed, a complete posterior 236 DISEASES OF THE EYE. synechia may ultimately be established. When this occurs, the aqueous humor being still secreted behind the iris, the latter becomes bulged forward, like the sail of a ship, until it touches the peripheral part of the cornea, while the centre of the anterior chamber retains its normal depth. This condition is very liable to induce glaucomatous tension (secondary glau- coma) and consequent loss of vision ; or, if the eye escape this danger, the traction on the ciliary body produced by the tensely stretched iris may develop chronic inflammation of the ciliary body and choroid — so-called chronic irido-cyclitis, or irido-cho- roiditis ; and this may lead to diminished tension and phthisis bulbi, with detachment of the retina and calcification of the lens. Or, the eye having been first blinded by high tension, may at a later period undergo phthisis bulbi. Complete posterior synechia may of course result from the first and only attack of iritis, and not by means of repeated relapses. In some cases of plastic or seroplastic iritis, the vitreous humor becomes more or less opaque, and this condition does not always disappear as the iritis gets well. Or, it may not be pos- sible to ascertain its presence until after the inflammatory process in the iris has subsided. Very great and permanent deteriora- tion of vision may result in such instances, and they emphasize the importance of a cautious prognosis at the commencement. There can be no doubt but that in these cases the ciliary body is inflamed along with the iris, although the fact cannot be directly ascertained. Causes. — Iritis is not common in children, except as complica- ting a corneal process or as a result of congenital syphilis. Toward puberty slight plastic iritis is sometimes found in girls. Youth and middle age are the times of life in which iritis is most often seen, while in old age it again becomes rare. More than fifty per cent, of the cases depend on syphilis, and a large proportion of the remainder are due to rheumatism. During desquamation after smallpox plastic iritis is some- times observed. In metria and septicaemia purulent iritis THE IRIS. 237 occurs, as also with typhoid fever, pneumonia, and recurrent fever. Diabetes sometimes causes iritis of a plastic or puru- lent form. Treatment. — Atropine is, above every other, the most impor- tant means. It is most commonly used in solution (Atrop. sulph. gr. iv, Aq. dest. sj) as drops ; but an atom of sulphate of atro- pine in substance, placed in the conjunctival sac, gives a very active reaction, and I prefer its use in one or other of these forms. It is also used in the form of an ointment (Atrop. sulph. gr. iv, vaselin $j), and gelatine discs containing atropine are manufactured. By paralyzing 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 are yet present the dilatation will greatly aid in preventing their formation. To produce a max- imum effect, where it is desired to break down adhesions, six drops should be instilled into the eye, with an interval of from five to ten minutes between each ; and, in this way, every drop has time to make its way into the anterior chamber, and finally the accumulated effect of all six is obtained. More than one drop can hardly be retained in the conjunctival sac at a time. The usual run of cases of iritis require a drop in the eye from twice to four times a day. Some individuals are peculiarly susceptible of 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 i grain used hypodermically neutralizes -^-^ grain of atropine in the system. Atropine poisoning occurs by reason of introduction of the solution into the stomach through the lachrymal canaliculi and the nose and fauces, and in order 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 in- troduction of the drop into the eye. After long use of atro- pine, the skin of the lower eyelid, or of both eyelids, from infiltration with the drug, often becomes eczematous, red, 238 DISEASES OF THE EYE. swollen, and painful ; and in other cases follicular conjunc- tivitis is induced. If these occur, sol. extr. belladonnse (gr. viij ad ,^j) should be substituted for atropine, and suit- able remedies (see pp. 87 and 132) used for skin or con- junctiva. In old people, tenesmus and retention of urine sometimes result from use of atropine. Atropine, while it is so useful a means 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 state- ment very explictly, for some, perhaps I should say many, medical men, who have not devoted attention to the subject of eye disease, habitually include atropine in every eye-water they prescribe. If the disease prescribed for be conjunctivitis, as it very often is, 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. In these days, it falls to the lot of most ophthalmic surgeons to be called, at one time or another, to a case of acute glaucoma, brought on by the gratuitous use of atropine in this manner. It is to be feared that the reason for this random prescribing of atropine is to be found in an ignorance of diagnosis, which leads prac- titioners to throw atropine with a number of other drugs into their eye-waters, in the hope that some of the ammunition will hit the mark, wherever the latter may be. Dark protection spectacles should be worn by patients suffering from iritis ; and, in severe cases, they should be con- fined to a dark room, and even to bed. In Simple Plastic Iritis, iodide of potassium or perchloride of mercury may be given internally. If there be much irrita- tion, pericorneal injection, or chemosis, leeching at the ex- ternal canthus is of use. Intermittent warm fomentations (every two hours) promote healthy vascular reaction. Pain THE IRIS. 239 is to be relieved by hypodermic injections of morphia and by chloral internally. In the rheumatic iritis, and in iritis due to diabetes, salicylate of sodium in large doses (20 to 30 grains every three hours) has often a remarkably favorable effect. In Serous Iritis, a small quantity of atropine will suffice, as there is little tendency to the formation of synechise ; and the irritation being slight, leeching is unnecessary. The skin (pilocarpine hypodermically, Turkish baths, and dry rubbing), kidneys, and bowels should be acted on ; and to the diuretics prescribed some iodide of potassium may be added. Turpentine in 5j doses, as recommended by Carmichael, of Dublin, is often a useful remedy here. Mr. John Tweedy prefers Chian turpen- tine in 5-grain doses every three, four, or six hours. Blistering on the temples, or behind the ears, is with many surgeons a favorite remedy. It adds to the annoyance of the patient, but I have no belief in it as a remedy in this, or, indeed, in any other eye disease. Great care is required in watching the tension of the eye in this form of iritis, and, if it be found to increase and to remain high for three or four days, paracentesis of the anterior chamber must be performed to reduce it temporarily while the iritis is still progressing toward cure. This little operation will also be called for if there be much deposit on the posterior surface of the cornea, as by means of it the deposit, to a great extent, may be floated away. (For mode of performing paracentesis see p. 191.) In Parenchymatous Iritis it is important to obtain rapid absorption of the inflammatory products, which are so abun- dantly thrown out, and which, in an organ like the eye, would soon cause extensive destruction. Consequently, unless it be the purulent form, the system should be put under the influence of mercury as quickly as possible by the use of inunctions of mercurial ointment, or by small doses of calomel internally ; and this treatment is indicated even when the inflammation is not of 240 DISEASES OF THE EYE. syphilitic origin. Warm fomentations are useful. An after- treatment with iodide of potassium is to be employed. In syphilitic iritis of the plastic form von Graefe was fond of the following formula: — R. Hydrarg. biniodid.jgr. vj ; Potass, iodidi, 5 iss ; Aq. destill., ^ss ; Syr. aurant., 51188. M. A teaspoonful to be taken once a day. The dose to be gradually increased. In Purulent Iritis, quinine and salicylate of sodium are the most suitable internal remedies. Injuries of the Iris. Punctured Wounds of the eye 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 apt to emanate. If a simple incised wound of the iris be observed, it may be regarded as of little importance, for inflammatory reaction need not be feared, and any extravasation of blood into the anterior cham- ber (hyphsema) becomes absorbed, while, as a whole, the func- tions of the iris will probably not be affected. 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 humor being lost. It is necessary always to remove such a foreign body without delay, although for some time it may cause no reaction. An incision should be made with a Graefe's knife at the margin of the cornea corresponding to the position of the foreign body, and the portion of iris containing the foreign body is then re- moved with forceps and scissors. Blows on the Eye are apt to cause one of several remarkable lesions of the iris, namely : — 1. Iridodialysis (J'pt?, dtdXu(Ti<^, a separating), i. e., separation of the iris from its attachment to the ciliary body, which is usually accompanied by considerable hyphaema. As much as one-half THE IRIS. 241 of the circumference of the iris may be involved in the lesion (Fig. 92), or the latter may be so small as to be detected only by aid of light transmitted to the eye by the ophthalmoscope ; and then not only the physiological pupil, but also the minute marginal traumatic pupil, will be illuminated. The functions of the eye after such injury, even when extensive, may be but little disturbed, or there may be monocular diplopia. Restoration to the normal state in these cases rarely takes place. I have observed one case in which the iridodialysis, a very minute one, was healed, and there is one other such case recorded. The lengthened use of atropine is the most likely way to promote such a result, which can only be hoped for if the iridodialysis be not extensive, and the case be seen early. 2. Retroflexion of the Iris. — :A portion of the iris in its entire width becomes folded back on the ciliary processes, giving the appearance 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 retroflexion, for the processes, being covered by the retroflected 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. 3. Rupture of the Sj^hincter Iridis. — There are not many cases of this lesion recorded; although, according to Hirschberg,"^ in all cases of permanent traumatic mydriasis the margin of the pupil is torn. My observations do not agree with this view of Hirschberg's, nor do I agree with him in thinking, as he seems to do, that rupture of the sphincter would be sufficient to account for traumatic mydriasis. This condition is also in- curable. ^ Centralbl.f. Augenheilk., 1886, p. 368. 21 242 DISEASES OF THE EYE. 4. Traumatic Aniridia. — The whole iris may be torn from its ciliary insertion and found lying in the anterior chamber, or under the conjunctiva, having in the latter case passed through a rent at the corneo-scleral margin. 5. Anteversion. — This must always be accompanied with irido- dialysis. The detached portion of iris is then twisted on itself, so that the uveal surface is turned to the front.* 6. Traumatic Mydriasis. — Permanent dilatation of the pupil after a blow is not very uncommon, and is commonly referred to paralysis of the sphincter, the result of concussion of the delicate nerve endings in the sphincter itself. (See above, under Rupture of the Sphincter Iridis.) New Growths of the Iris. Cysts. — 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 kind was said to result always from a trauma causing an anterior synechia, or otherwise shutting off a fold of the iris, which became distended into a cyst by accumu- lation of aqueous humor. A case, however, which was not pre- ceded by a trauma has come under my notice. The cysts with solid contents (epidermoid elements) are believed to have their origin in an eyelash or morsel of epidermis, which may have made its way into the anterior chamber by occasion of a perfor- ating corneal wound. All these cysts are sources of serious danger to the eye (irido-choroiditis, glaucoma, etc.), and, it is 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 tumor be small, but if it have attained a large size the attempt may be unsuccessful. 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. Granuloma is the name given to a benign neoplasm of the iris, * L. Werner, in Ophth. Rev., 1887, p. 104. THE IRIS. 243 of which the structure resembles granulation tissue. Clinically it is a small, pale tumor, or there niay be several such tumors, which gradually grow to fill the anterior chamber, rupture the cornea, and finally induce phthisis bulbi. It is held by some that these growths depend on a syphilitic taint, and by others that they are tuberculous. Tubercle. — This appears as small white tumors, from the size of a pin's head to that of a pea and larger. Microscopically they contain small, round cells, and the characteristic giant cells. By early removal of the eye oue may hope to avert general tuberculosis, as a case of Deutschmann's"^ shows. Primary Sarcoma (or Melano- Sarcoma) is a rare disease of the iris. When the tumor is very small it may be removed by an iridectomy, and in this way an attempt made to preserve the eye ; but when it has attained any size, the whole eyeball must be removed. Congenital Malformations of the Iris. Heterophthalmos (iz^pn^ different, ocfda/./jjj^). — This term indicates that the color of the iris in one eye is different from that in the other. Corectopia (y-oprt^ the j^ujnl; exzo-o'^, out of position), or mal- position of the pupil. The pupil sometimes occupies a position further from the centre of the iris than normally. Polycoria (-uXu?, many; xopy], 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 may be situated very near the periphery of the iris. In neither case has it a special sphincter. Persistent Pupillary Membrane appears in the form of very fine threads stretched across the pupil ; and these diflTer from posterior synechise in being attached to the anterior surface of the iris some distance from the margin of the pupil. They do not interfere with the motions of the pupil nor with vision. * Graefe's Archiv, xxvii, pt. 1, p. 317. 244 DISEASES OF THE EYE. Coloboma {■/.<>h>t36i, maimed). — This is a cleft in the iris Fig. 93. Fin. 94. Fig 95. n Fig. 96. caused by an arrest of development (incomplete closure of THE IRIS. 245 the choroidal fissure). It is situated almost always in the lower inner quadrant, at a position corresponding to the choroidal fissure in the foetus, and it varies much in size in different cases. It is sometimes continued into the ciliary body and choroid, and may be present in both eyes, and a notch at a corresponding situation in the crystalline lens is not uncom- mon. When uncomplicated, it causes little or no defect in vision. Irideremia (.'V>.'c, ipr^pla^ wcnit of). — This may be complete or partial. In the latter case it may be the inner circle 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 double- FiG. 97. sided. The patients suffer chiefly from dazzling by light, for which either protection or stenopaeic spectacles are to be prescribed. Operations on the Iris. Iridectomy. — This is performed for optical purposes, as in zonular cataract, corneal opacities, or closed pupil ; for anti- phlogistic purposes, as in recurrent iritis, etc. ; and to reduce abnormally high intraocular tension in primary and secondary glaucoma. The instruments required are : A spring speculum, a fixation forceps with spring catch (Fig. 97), a lance-shaped iridectomy knife (Keratome) (Fig. 93), or a Graefe's cataract knife, a bent iris forceps (Fig. 94), or a Tyrrell's hook (Fig. 95), an iris scissors curved on the flat (Fig. 96), and a small spatula. The width of the coloboma depends a good deal on the length 246 DISEASES OF THE EYE. 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 colo- boma be desired, the incision must be long, and must lie actually in the corneo-scleral margin ; the iris forceps being then intro- duced, a portion of the iris corresponding to the length of the incision may be seized and cut off, and a coloboma, as at Fig. 98, produced. Somewhat inside the corneal margin will give a pupil as in Fig. 99. A narrow coloboma (Fig. 100) is ob- tained by a short corneal incision, which may be more or less peripheral as circumstances require, and by using a Tyrrell's hook, instead of an iris forceps, for catching and drawing out the iris. In glaucoma, a wide and very peripheral coloboma is required. Fig. 98. Fig. 99. Fig. 100. For antiphlogistic purposes, a wide iridectomy is also necessary. But for optical purposes, a narrow iridectomy is required ; be- cause, with a wide coloboma, the diffusion of light may be very troublesome to the patient. The best position for an iridectomy for glaucoma, or for anti- phlogistic purposes, is the upper quadrant of the iris, as there the subsequent dazzling by light and the disfigurement are least. But the position, by 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 down- ward, or if that place be ineligible, then downward and out- ward, or directly downward, or directly inward. The upward positions are not satisfactory for optical pupils, owing to the over-hanging of the upper lid ; but yet it often happens that we have no other choice. THE CILIARY BODY. 247 III 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 cor- nea and close to the latter. The point of the lance-shaped knife is then to be entered almost perpendicularly to the surface of the cornea, and made to penetrate the latter. The handle of the • knife is then at once lowered, and the blade passed 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 an- terior chamber. At the same time the aqueous humor flows off and the crystalline lens and iris come forward. The fixation- forceps is now given over to the assistant, and the bent iris- forceps, held in the left hand, is passed closed into the anterior chamber, its points directed toward the posterior surface of the cornea, so as to avoid entangling 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 iris is seized and drawn out to its full extent through the corneal incision. AVith 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 colo- boma do not remain in the wound ; and, if they are seen to do so, they may be reposed by stroking the region of the incision with a hard-rubber spoon, or by actually pushing them into their places gently with the spatula. Iridotomy. — For description and uses of this operation see Chap. XIII. Cyclitis (Inflammation of the Ciliary Body). Cyclitis is often present to a slight degree as an extension of inflammatory affections of the iris or choroid, although its presence in many of these cases cannot be clinically determined. 248 DISEASES OF THE EYE. The Symptoms of Cyclitis in general are : marked circum- corneal injection, ciliary neuralgia, pain on pressure of the ciliary region, very deep anterior chamber, opacity in the anterior part of the vitreous humor, and, sometimes, hypo- pyon in the anterior chamber. There are three forms of cyclitis : — 1. Plastic Cyclitis. — Here the circumcorneal injection is very decided, and there is venous congestion of the iris. The anterior chamber is deep, owing to retraction of the periphery of the iris by inflammatory exudation in the ciliary body, and, for the same reason, the pupil is dilated. The inflammation may extend to the iris or to the choroid, in which latter case the vitreous may become very opaque. Violent ciliary pains attend the affection, and the eyeball is very tender on pressure of the ciliary region. The intraocular tension is reduced. 2. Serous Cyclitis. — The circumcorneal injection is but slight. The anterior chamber is often at first deeper than normal, owing to hypersecretion of aqueous humor or to effusion of fluid inflammatory products from the ciliary body, there is keratitis punctata, and the anterior part of the vitreous humor is filled with a fine dust-like opacity. Serous iritis may come on, and the danger of glaucomatous increase of tension is very great. Unless increase of tension give rise to it, pain does not often attend this form. 3. Purulent Cyclitis. — Here the circumcorneal injection is very well marked. The vitreous humor is filled with mem- branous opacities. There is hypopyon in the anterior chamber, which has the characteristic of appearing and disappearing at intervals of a few days. There is severe ciliary neuralgia. Purulent iritis, or choroiditis, or both, are apt to supervene. Prognosis. — In an early stage all these forms are capable of undergoing cure and of leaving the eye in a fairly useful condition. On the other hand, serous cyclitis, as already stated, is liable to produce secondary glaucoma; while the purulent form leads to atrophy of the iris and choroid, dis- organization of the vitreous humor, detachment of the retina. THE CILIARY BODY. 249 cataract, and phthisis bulbi ; and the plastic form, in addition to serious damage to the affected eye, similar to that produced by purulent cyclitis, has, more than either of the other forms, the tendency to cause sympathetic uveitis of the other eye. The shrunken eyes resulting from this affection are often very liable to attacks of inflammation, and frequently remain painful to the touch, circumstances which indicate that chronic cyclitis is still present, and consequently such stumps are a constant source of danger to the sound eye. Causes. — Primary idiopathic cyclitis is a rare affection. Trau- mata are the most common causes of the affection. Both the plastic and the purulent form are liable to occur after cataract operations. The Treatment for cyclitis is similar to that for iritis. Leech- ing at the outer canthus is often of great benefit. Injuries of the Ciliary Body. Punctured Wounds, and Foreign Bodies perforating the scler- otic 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 ; 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 caught in the sclerotic wound in healing, or if a foreign body be present in it, or, indeed, anywhere within the eye; and this traumatic cyclitis is more likely to produce sym- pathetic ophthalmitis than the idiopathic form. Hence, a region around the cornea about 5 mm. wide is aptly termed by Nettle- ship the " Dangerous Zone." New^ Growths of the Ciliary Body. Sarcoma occurs here, and often passes unobserved, until it attains considerable size as a brown mass, for it is concealed from view by the iris. Occasionally it makes its first appearance 250 DISEASES OF THE EYE. at the angle of the anterior chamber. Removal of the eyeball is indicated, and will often for a time be declined by the patient, as sight may be but slightly affected in the early stages. Myosarcoma originating in the ciliary muscle has been ob- served a few times. Choroiditis. There are two great forms of inflammation of the choroid, the exudative and the purulent. Of the exudative form, again, there are several kinds, namely, disseminated choroiditis, central choroiditis, central senile choroiditis, guttate choroiditis, and syphilitic chorio-retinitis. Disseminated Choroiditis. — The usual Ophthalmoscopic Appear- ances of this disease consist either in round white spots of dif- ferent sizes with irregular black margins, or in small spots of pigment ; these changes being surrounded by healthy choroidal tissue ; or there may be few or no white patches, but rather spots of pigment surrounded by a pale margin. The retinal vessels pass over, not under, 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 represent a rather late stage of the disease, the early stage not usually coming under observation. It con- sists in small circumscribed plastic exudations into the tissue of the choroid, which, seen with the ophthalmoscope, give the ap- pearance of pale pinkish-yellow spots. The exudations may undergo absorption, leaving the choroid 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 neighborhood, and hence the white patches with black margins above described. Sometimes, in addition to the above changes, the pigment- epithelium layer all over the fundus becomes atrophied, ex- posing to view the vascular network of the choroid, while here and there small islands of pigment are present. Opacities in the vitreous humor are sometimes found. THE CHOROID. 251 Causes. — Disseminated choroiditis is due to acquired syphilis in a considerable number of the cases. In a very large propor- tion of cases no ascertainable cause exists ; and these, there is reason to suspect, are congenital, and, probably, many of them dependent on an inherited syphilitic taint. In eyes with con- genital cataract patches of choroiditis are often found. Prognosis. — Disseminated choroiditis is always a serious dis-. ease, and complete recovery cannot be looked for. The degree of defect of sight it causes depends much on the extent to which the region of the macula lutea has become involved. Treatment. — In fresh cases due to acquired syphilis a pro- longed but mild course of mercurial inunctions is the most suitable measure, 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 potas- sium internally may be of use ; while in the cases due to other causes, small doses of perchloride of mercury may be given ; and in all cases, from whatever cause, dry cupping on the temple, or even the artificial leech, should be employed. 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. Syphilitic Choroido-Retinitis. — See Syphilitic Retinitis, Chap. XV. Central Senile Guttate Choroiditis. — Under this name an appearance has been described by Mr. Waren Tay and others, which consists of fine white, pale yellow, or glistening dots, best seen in the upright image, and situated chiefly about the macula lutea, or between this and the optic papilla. These dots are due to colloid degeneration with chalky forma- tions in the vitreous layer of the choroid,* which give rise to secondary retinal changes. The functions of the retina usually suffer in a marked manner, so that a partial central *Hir8chberg and others, Centralbl. f. prakt. Augenheilkvnde, 1884, p. 46. 252 DISEASES OF THE EYE. 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 also found in middle age, and even in youth. It should always be looked for in cases of incipient cataract; for when the lental opacity is more advanced it cannot be seen, while functional examination does not then detect it. Treatment is of no avail. Central Choroiditis is an exudation at the macula lutea, without any similar disease elsewhere in the fundus. Abso- lute central scotoma is its prominent symptom, and syphilis its usual cause. Treatment. — Active mercurialization ; and, where this can be adopted early, the prognosis for recovery of sight is fair. Central Senile Areolar Atrophy of the Choroid. — Although this is not an inflammatory process, yet it is most convenient to refer to it here. It is not a very rare disease, and presents the appearance of a white patch, often of considerable extent, at and around the macular region. I think I have observed that, in some cases, a hemorrhage in the choroid and posterior layers of the retina formed the starting-point of the disease. The retinal functions always suffer much, for an absolute central scotoma is produced which renders all near work impossible, although locomotion is not much impeded, as the periphery of the field remains intact. The discovery of the presence of this disease after a cataract has been successfully removed is sometimes a source of intense disappointment, both to patient and surgeon, which cannot be guarded against unless it has been noted while the cataract was still incipient. Treatment is of no avail. Purulent Choroiditis. — This consists at first in a purulent ex- travasation between the choroid and retina, and into the vitreous humor, recognizable by the yellowish reflection obtained from the interior of the eye on illuminating it. The eyeball may be- come hard, the pupil dilated, and the anterior chamber shallow. THE CHOROID. 253 Purulent iritis with hypopyon soon comes on, and the cornea may also become infiltrated and slough away. There is usually considerable chemosis. The eyeball is pushed forward by inflammatory infiltration of the orbital connective tissue. The eyelids are swollen and congested. There is intense pulsating pain in the eye and radiating pains through the head ; and in this stage all the tissues of the eyeball are engaged in the purulent inflammation, and the condition is termed Panophthal- mitis. Purulent choroiditis does not always reach this latter stage, but may remain confined chiefly to the choroid, vitreous humor, and iris. The pain in such cases is not severe, and when the af- fection occurs in children it may be mistaken for glioma ; indeed, the name pseudoglioma has, unfortunately, been given to it. It is distinguished from the malignant disease by the muddy vit- reous usually present in it, by the posterior synechise, and by the retraction of the iris periphery, with bulging forward of its pupillary part. Prognosis. — The ultimate result, in the vast majority of cases, is loss of sight, with phthisis bulbi. The severe cases go on to bursting 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 men- ingitis (Niemeyer), that a certain number of cases of irido- choroiditis 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, nor are they very liable to give rise to sympathetic ophthalmitis ; which latter observation is also true of the acute purulent process itself. Causes. — The most common causes of purulent choroiditis are wounds of the eyeball, whether accidental or operative (especi- ally cataract extractions), foreign bodies piercing and lodging in the eyeball, and purulent keratitis. It may also come on sud- denly in eyes which are the subjects of incarceration of the iris in a corneal cicatrix. 254 DISEASES OF THE EYE. It is seen as embolic or metastatic choroiditis, iu connec- tion botli with epidemic and sporadic cerebro-spinal mening- itis ; in some cases of metria, similarly as purulent retinitis (Chap. XV) ; in pyaemia of the ordinary type, and in endo- carditis. In infancy and childhood, besides its occurrence with cerebro- spinal-meningitis, it has been known to be caused by, or associated with, inherited syphilis, measles, bronchitis, diarrhoea, whooping cough, and omphalo-phlebitis ; and it is more than probable that in every instance some infective blood-disease is the fundamental cause of the process, although it may not always be possible to detect the existence of that blood dis- ease. Treatment may be said to be powerless in this disease. The most one can do is to try to diminish the pain by warm fomenta- tions, poultices containing powdered conium leaves, hypodermic injections of morphium, or, finally, by giving exit to the pus by a free incision in the eyeball, followed by a copious irrigation with weak sublimate lotion, so as to wash out the whole con- tents of the scleral cavity. Quinine and chlorate of potash are suitable internal remedies. I agree with those who think that enucleation of the eyeball should not be undertaken during purulent choroid- itis in the acute stage, as it is liable to lead to purulent meningitis and death ; but there are surgeons who do not recog- nize any such danger, and who practice enucleation in this condition. Posterior Sclero-Choroiditis, or Posterior Staphyloma. — This condition is described in connection with myopia (Chap. II, p. 36), which is its almost constant cause. Detachment of the Choroid.— As the result of copious loss of vitreous, during operations or from injury, detachment of the choroid is not uncommon, but it does not require to be specially diagnosed in these instances, and therefore it is not important to consider it further here. But idiopathic detachment of the choroid, although ex- THE CHOROID. 255 tremely rare,* is of importance as forraiug a well-defined diseased condition in itself. The Ophthalmoscopic Appearances here are apt to be taken at first glance for detachment of the retina simply. Bnt on closer inspection the choroidal stroma is observed to lie im- mediately 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 choroid is not completely detached, but is separated from the sclerotic in several ditierent places, and these detachments are seen in the form of apparently solid hemispherical protuberances rising abruptly from the fundus into the vitreous humor. In other places the choroid is in contact with the sclerotic, although in some of these posi- tions there may be detachment of the retina alone. The vitreous humor is more or less opaque. Xeedlesa to say, vision is greatly lowered or quite destroyed. It is probable that a chronic choroido-retinitis has been an antecedent condition in all of these cases. Indeed, there often are signs of old retinitis present, such as perivasculitis and connective tissue striation ; and, in one case, a retinitis was actually observed long before the detachment of the choroid came on. Adhesions between the choroid and sclerotic are formed in consequence of this inflammation, and then inflammatory exudation takes place behind the choroid, and separates it from the sclerotic where it happens not to be adherent to the latter. The process ends either in phthisis bulbi, in consequence of vascular changes and disturbances of nutrition, or in cure of a certain kind, 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 choroid and retina to their normal position is rendered possible ; but, even then, restora- tion of sight, with tunics so disorganized, cannot be looked for. * The most recent case of the kind, and one of the best observed, is reported by Story in Trans. Ophth. Soc, 1S91, p. 12. 256 DISEASES OF THE EYE. Treatment hitherto seems to have been of no avail. Pro- bably active mercurialization might afford the best chance of doing good, should a case come under notice. Injuries of the Choroid. Small Foreign Bodies may pierce the sclerotic, or the cornea and lens, and lodge in the choroid, and can often there be detected with the ophthalmoscope. They require operative removal by the magnet, if metallic; or if this cannot be carried out, or that the foreign body is non-metallic, the eye- ball must be removed, to avert sympathetic ophthalmitis. Incised Wounds of the sclerotic very frequently involve the choroid (see p. 228). Rupture of the Choroid is often produced by blows on the eye, and is seen with the ophthalmoscope as a whitish- yellow (the color of the sclerotic) crescent some two or three papilla-diameters in length and one or so distant from the optic entrance, the concavity of the crescent being directed toward the papilla. Immediately after the accident, extra- vasated blood sometimes prevents a view of the rupture. Some choroiditis may result, but when this passes away good vision is frequently restored and maintained, provided detachment of the retina does not ultimately supervene from cicatricial contraction at the seat of the rupture. Treatment. — Careful protection of the eye, and abstinence from use of it, with dry cupping at the temple. New Growths of the Choroid. Sarcoma. — This is by far the most common neoplasm of the choroid, and is seen at all times of life, but most frequently between the ages of 40 and 60. When highly pigmented, it is termed melano sarcoma. It may originate in any part of the choroid. If seen in a very early stage, it is easily recognized from its projecting over the general surface of the fundus; but, unless it be in the region of the macula lutea, it may not cause THE CHOROID. 257 auy serious disturbance of vision, and hence may not at that period be brought under the notice of the surgeon. The new growth soon gives rise to detachment of the retina by reason of serous exudation from the choroid, and this is ac- companied by opacity in the vitreous humor, which renders the diagnosis with the ophthalmoscope difficult or impossible. If the detachment be shallow and the retina translucent, the tumor may still sometimes be seen through the subretinal fluid by aid of strong illumination ; and even direct sunlight may be employed in some such cases. Owing to the great defect of vision which comes on in this stage, we very commonly see these cases then for the first time. The history of the case may aid us ; and the absence of the more usual causes of detachment of the retina should make us suspicious of an intraocular tumor. Soon the intraocular tension increases ; and this makes the diagnosis again more easy in many cases, for the combination of detached retina and increased tension exists only with intra- ocular tumors. 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. Still, if the case come now under observation 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 be 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 conjunctiva, it pushes the eyeball to one side, the upper lid being stretched tightly over the whole. On raising the lid the tumor is seen as a bluish-gray mass of irregular surface. The conjunctiva is now soon perforated, and the surface of the tumor becomes ulcerated, with a foul-smelling discharge and occasional hemorrhages. The tumor gradually invades the surrounding 22 258 DISEASES OF THE EYE. skin and the bones of the orbit, and, by extending through the sphenoidal fissure and optic foramen, reaches the base of the brain. It is, usually, upon the neighboring 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. Choroidal sarcoma is almost always primary, but it has been seen a few times as a metastatic disease. The entire progress of such a growth varies considerably. It may occupy but a few months, or it may extend over many years. Carcinoma. — This is extremely rare, and the cases of it on record were all of metastatic origin, the primary disease being in the breast. It is not possible to distinguish choroidal sar- coma from choroidal carcinoma by the ophthalmoscope. Tubercle is sometimes seen in cases of acute miliary tubercu- losis as round, slightly prominent, pale yellowish spots, of sizes varying from 0.5 to 2.5 mm. in diameter, situated always in the neighborhood of the optic papilla and macula lutea, and unac- companied by pigmentary or other choroidal changes. There may be but one of these tubercles, or there may be many of them. They occur, as a rule, in a late stage of the general disease, but have occasionally been noted long before its ap- pearance. In obscure cases of the general disease the ophthal- moscope has sometimes rendered valuable diagnostic aid by discovering these minute tubercles in the choroid. Very rarely, a tubercular tumor grows in the choroid in cases of general chronic tuberculosis, and attains a large size, the growth destroying the eye similarly as sarcoma or carcinoma. In young children it may be impossible to diagnose between a tubercular tumor of the choroid and a glioma of the retina (Chap. XV). As in either case enucleation is indicated, the diagnosis is not of much practical importance. THE CHOROID. 259 Other, but rare, forms of tumor of the choroid are : — Sarcoma Carcinomaiosum,^ and, in a case of ray own, Osteo- Sarcoma. f Treatment. — So long as, in cases of sarcoma and carcinoma, the tumor is wholly intraocular, enucleation of the eyeball should be performed, and may be done with fair hopes of sav- ing the patient's life if the disease be primary. When the orbital tissues have become involved, extirpation of all the con- tents 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 loathsome dis- ease, although the probable presence of secondary growths else- where renders but small the prospect of saving the patient's life. Cases of miliary choroidal tubercle do not call for direct treatment. In cases of tubercular tumor, the question of re- moval 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 has become extraocular, removal of the eye should be recommended. Congenital Defects of the Choroid. Coloboma. — This is a solution of continuity occurring always in the lower part of the choroid, and usually associated with a similar defect in the iris. It may commence at the optic papilla and involve the ciliary body also, and even the crystalline lens may have a corresponding notch, or it may not extend so far in either direction. The condition is recognized ophthalraoscop- ically by the white patch due to exposure of the sclerotic where the choroid is deficient. Sometimes the retina is absent over the defect in the choroid, a circumstance which may be ascertained by the arrangement of the retinal vessels; but, even if it be * Von Graefe'sArchiv, x, pt. 1, p. 179; Landsberg, Archiv, f. Ophthal., xi, pt. 1, p. 58 ; Trans. Acad. Med. in Ireland, i, p. 47. ^ Bericht der ffeidelberger, Ophthal. Gesellsch., 1883. 260 DISEASES OF THE EYE. present, its functions at the place are wanting, and a defect in the field of vision exists. Central vision is often normal. Albinismus, or the want of pigment in the choroid and iris. This is usually accompanied by defective pigmentation of the hair of the body. The iris has a pink appearance, due to reflec- tion of light from its blood-vessels and from those of the choroid, and, with the ophthalmoscope, the latter vessels can be seen down to their finest branchings. The light, 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 on, when some degree of pigmentation usually takes place. Much advantage may be derived in many of these cases by the use of stenopeic spectacles, at least for near work. Any defect of refraction should be carefully corrected. Sympathetic Ophthalmitis. By this term we understand a uveitis (irido-cyclitis, irido- choroiditis) caused by an irido-cyclitis of the other eye, the latter being usually of traumatic origin. The affection owes its name to the theory, held until a few years ago, that it was due to reflex action of the ciliary nerves. Although this view, which is no longer in accord with modern pathology, has given place to another, yet the original name of the disease is still retained, and we often speak of the injured eye as *' the exciting eye," while the secondarily affected eye is called the "sympathizing eye." The cyclitis most likely to cause sympathetic ophthalmitis is that set up by a punctured wound of the eyeball, especially a wound involving the ciliary body. The cyclitis set up by a foreign body which pierces the tunics of the eye and lodges in its interior is also of serious import, even though the ciliary body may not have been injured. Perforating corneal ulcers, and even simple incisions of the cornea, may form the starting-point of sympathetic ophthalmitis. It is an important SYMPATHETIC OPHTHALMITIS. 261 and interesting fact that eyes which are, or have been, the sub- ject of purulent panophthalnaitis do not give rise to sympathetic ophthalmitis. There is considerable doubt as to whether sympathetic oph- thalmitis can occur without a perforating lesion of the exciting eye. It has been held that a dislocated crystalline lens, or cyclitis caused by a blow on the eye, could serve as excitants of sympathetic ophthalmitis; but, if such cases do occur, they are very rare. I have myself never seen an instance of the kind. In cases of sympathetic ophthalmitis, the cyclitis of the ex- citing eye may be but slight, so slight, indeed, that vision is not seriously affected, or it may be severe. The degree of severity of the attack in the sympathizing eye does not depend on that of the inflammation in the exciting eye ; for, in many cases, the process in the sympathizing eye is a more severe one and more destructive to sight than that in the exciting eye. Sympathetic ophthalmitis is met with in persons of every time of life, but children under the age of puberty are more prone to it than in later years. Syinjyathetic Invitation, or Neurosis, is a condition of the second eye sometimes seen, and which must not be confounded with sympathetic ophthalmitis, nor is it to be regarded as a pre- monitory sign of the latter, for it may pass away without leaving any organic changes behind it. It consists in photo- phobia, lachrymation, pericorneal injection, and accommodative asthenopia, and is, very probably, a reflex neurosis. Premonitory Sign of Sympathetic Ophthalmitis. — Shrinking pain (the patient draws back his head in a most characteristic way) on pressure of the ciliary region of the exciting eye is almost always present where sympathetic ophthalmitis supervenes ; although it does not necessarily indicate that the latter is imminent, nor even that its ultimate appearance is certain. But there are no premonitory signs in the sympathizing eye prior to the attack of inflammation in it. Progress of Sympathetic Ophthalmitis. — Slight optic neuritis has been noticed in the sympathizing eye in some cases prior 262 DISEASES OF THE EYE. to, or simultaneously with, the outbreak of irido-cyclitis, and is, probably, of tolerably constant occurrence. But it is not the sign or symptom which commonly first attracts the atten- tion of the patient or of the surgeon. The process is usually first observed in the sympathizing eye as a serous irido-cy- clitis, with increased depth of the anterior chamber and keratitis punctata, and may maintain this character to the end. As a rule, it soon passes over to a plastic form with development of new vessels in the iris and shallowness of the anterior chamber. The tissue of the iris and ciliary body becomes infiltrated with lymph cells, and on their posterior surfaces and in the pupil a deposit of lymph cells takes place, the choroid also becoming similarly infiltrated, and connective tissue is developed in its exudation. The vessels of the uveal tract are destroyed by pressure of the newly-developed connective tissue ; the vitreous humor con- sequently shrinks, causing detachment of the retina, cataract, and phthisis bulbi. Or the process may be confined chiefly to the anterior segment of the eyeball, the iris, ciliary body, and lens, and may merely cause disorganization of those parts with shallow anterior chamber — a condition known as phthisis anterior — while the vitreous humor, retina, and choroid remain healthy. In such cases, of course, vision is much damaged. Or, again, very occasionally, in some mild cases, the exudation may be- come absorbed, and leave a tolerably clear pupil and media, with more or less useful sight. The shortest period at which, after irido-cyclitis has been set up in the injured eye, sympathetic ophthalmitis is liable to appear, seems to be about twelve or fourteen days, and the longest about twenty years. The most usual interval is from six to eight weeks. Nature of the Disease. — Investigations made in recent years* * Knies, Sitzungsber d. Ophth. GeseUsch , 1879, p. 52; Leber, A. v. Graefe's Archiv, xxvii, pt. 1, p. 325 ; Brailey, Trans. Internat. Med. Con- SYMPATHETIC OPHTHALMITIS. 263 have placed it beyond doubt that sympathetic ophthalmitis is an inflammation, propagated to the sympathizing eye by direct continuity through the optic nerves and chiasma from the exciting eye, as erysipelas extends over the skin, and that the micro-organism known as Staphylococcus pyogenes albus, or aureus, is the active element in the process. This fact has suggested the term Migratory Ophthalmitis for the disease. Prognosis. — This disease is one of the most serious to which the eye is liable, leading, as it does, in the vast majority of cases, to absolute and incurable blindness. It is but rarely that the sympathizing eye escapes with some useful vision. Treatment. — The most important point is the prevention of the extension of the inflammation to the other eye. Sir W. Bowman * found it possible, in private practice, by careful nursing for a year or more, to save some eyes with severe wounds, and to prevent the occurrence of sympathetic ophthal- mitis. Abadie recommends t that, when the case comes under treatment early, antiseptic measures be taken to prevent infection ; and that, if these fail, the actual cautery be applied to the wound ; and that, if this be not enough, one or two drops of a 1 in 1000 solution of sublimate be injected into the wounded eye, and where the second eye has become aflfected, one or two drops of the same solution be injected into the vitreous humor of that eye. He has found these gress^ 1881, vol. iii ; Snellen, Trans. Internat. Med. Congress^ 1881, vol. iii ; Macgillivray, Amsterdam Internat. Med. Congress^ 1879 ; Berlin, Volkmann' s Samml. Klin. Vortrdge, No. 185, 1880 ; Deutschmann, A. v. Graefe's Archiv, xxx, pt. 3, p. 77, xxxi, pt. 2, p. 277, and " Ueber die Ophthalmia Migratoria," 1889 ; Gifford, Archivesof Ophthalmology, 1886, p. 281. Randolph, in Arch, of Ophthal., vol. xvii, p. 188, does not support the theory of extension of the process through the optic nerves and chiasma, but he does not offer an alternative explanation. * Ophthal Rev., 1882, p. 228. t Annates d'' OcuUstique, Mars-Avril, 1890. 264 DISEASES OF THE EYE. injections of use in checking, or ameliorating, sympathetic ophthalmitis. But the only measures generally admitted to be certain prophylactics, when employed in time, and the only ones applicable to the great mass of those with whom we have to deal, are removal of the injured eye, evisceration, and Mules's operation ; and a most difficult question sometimes presents itself when, in a given case, we have to decide as to the necessity for one of these measures. The following rules guide me in ray own practice at present : — 1. Although danger to the second eye practically does not arise until inflammation has been set up in the exciting eye,* yet I would perform primary enucleation, evisceration, or Mules's operation on the latter if it had been so injured as to make recovery of sight almost hopeless, and the onset of irido-cyclitis almost certain. 2. I would enucleatet in the same case, were irido-cyclitis already set up in the injured eye. 3. I would enucleate in a case of irido-cyclitis where a foreign body which could not safely be extracted was present in the eye, even though the vision were fairly good ; because we know that here the danger of sympathetic ophthalmitis amounts almost to a certainty. 4. I would enucleate in a case of acute irido-cyclitis, traumatic or idiopathic, where vision was lost, especially if the eye were tender on pressure ; for here the eyeball is useless and disfigur- ing, and apt to be a source of danger to its fellow. 5. I would enucleate in a case of phthisis bulbi, even of old standing, where there was shrinking pain on pressure, for the same reasons as in Xo. 4. * A few cases are recorded in which, although the exciter was removed almost immediately after the injury, yet sympathetic ophthalmitis supervened. t For the sake of brevity, the word enucleation only is used in what follows, but evisceration, or Mules's operation, is equally implied. SYMPATHETIC OPHTHALMITIS. 265 6. I would enucleate in a case where the sympathizing eye is already affected, provided vision in the exciting eye be lost and hopes of its recovery but slight, if any ; for improvement in the sympathizing eye, or a greater amenability of it to treatment, has been frequently observed after this has been done. Brailey, however, holds that enucleation is not in this instance to be rec- ommended, as he believes it tends to aggravate the condition of the sympathizing eye — to change a serous into a plastic uveitis. 7. I would enucleate in a case of sympathetic irritation, if the sight of the exciting eye were very defective and the neurosis very persistent. 1a. I would not remove any injured eye, unless it contained a foreign body which I could not extract, if its sight were fairly good, and as yet no sign of inflammation present. For inflam- mation may not come on, and the eye may possibly be saved. 2a. I would not enucleate the exciting eye, if sympathetic ophthalmitis had already appeared, should the vision of the ex- citing eye be fairly good. (Contrast this with Rule 6.) For it often occurs that the process in the sympathizing eye is not ar- rested by the proceeding, and that, where the latter is not under- taken, the exciting eye turns out in the end to be the organ with the better vision. Cases have been observed in which sympathetic ophthalmitis broke out some days after removal of the exciting eye. In these •instances the inflammation, no doubt, had already started on its journey from the exciting eye, the removal of which did not ar- rest its progress. Inasmuch, then, as the inflammation takes some twelve to fourteen days (vide supra) to travel from one eye to the other, one cannot feel certain of having averted sympathetic ophthalmitis before that period at least has elapsed after enucle- ation of the exciter ; and it is well to impose abstinence from use of the eye, or exposure of it to much light, for that time or longer. This fact is not to deter the surgeon from recommend- ing enucleation when indicated, for in the vast majority of cases it has the desired effect, and even in the cases where sympathetic ophthalmitis was not averted, the inflammation in 23 266 DISEASES OF THE EYE. the sympathizer was usually of a mild type and yielded to treatment. As substitutes for enucleation of the eyeball in these cases, division of the optic nerve in the orbit (optic neurotomy), resection of a piece of the optic nerve in the orbit (optic neurectomy), and evisceration or exenteration of the eyeball, have all been proposed and practiced. Optic Neurotomy is still employed by some surgeons ; but by most it has been abandoned, under the impression that it does not afford good protection against sympathetic ophthalmitis; for the cut ends of the nerves reunite, and at least one case* has been observed in which, several months after the optic neurotomy, sympathetic ophthalmitis appeared. Optic Neurectomy was first advocated by Schweigger, f and is, in his opinion, a better protective than enucleation. The views of other surgeons have not yet been published, and I have myself too little experience of the method to form an opinion on it, but it would seem to recommend itself as rational. Evisceration is still on its trial as a prophylactic measure for sympathetic ophthalmitis. A few cases { are on record in which the good eye became affected not long after evisceration of the exciting eye, but this has taken place, too, as above stated, after enucleation ; and so far as we can yet form an opinion, the prophylactic value of evisceration is at least as great as that of enucleation. The mode of performing the operation, and Mr. Mules's modification of it, are given at pp. 214 and 215. The indications for these various procedures are the same as for enucleation. Sympathetic ophthalmitis having broken out, and the ques- tion of enucleation, or other prophylactic measure, having been decided in one sense or the other, the means to be directed * Leber, A. v. Graefe's Archiv, xxvii, pt. 1, p. 339. t Archives of Ophthalmology, xiv, p. 223. 1 By F. R. Cross, Proceed. Ophthal. Soc, July, 1887. SYiAFPATHETIC OPHTHALMITIS. 267 against the process in the sympathizing eye have to be consid- ered. The patient should be confined for a lengthened period to a dark room and atropine used for the eye, while the general system is maintained by a touic but non-stimulating treatment. It is doubtful whether other means are of much value. Mercurialization is employed by some surgeons in these cases, but its value is problematical. No operation should be undertaken for the formation of an artificial pupil in the sympathizing eye until the inflammatory process has completely subsided, the tension of the eye improved, and the vascularity of the iris diminished. This period is, at the least, from twelve to eighteen months after the onset of the disease. If operative interference be resorted to during that period, the result is an aggravation, or rekind- ling, of the inflammation, with closure of the artificial pupil which may have been made, in consequence of proliferation of the layer of retro-iritic connective tissue. Not even if the eyeball become of glaucomatous hardness, as sometimes happens, should the surgeon be tempted to operate. This is a golden rule. Of the operations employed for the establishment of an arti- ficial pupil in an eye which has suflTered from sympathetic ophthalmitis resulting in anterior phthisis, iridectomy most naturally suggests itself and is the least satisfactory. The reason of this is that, owing to its very disorganized state, the iris tears when drawn on by the forceps ; and, hence, the formation of a satisfactory coloboma is almost impossible, and even if this be obtained it is extremely liable to close again from proliferation of the retro-iritic connective tissue set going anew by the irritation of the operation. Yet sometimes, after repeated iridectomies, a permanently clear pupil is obtained. Von Graefe operated by making a peripheral linear incision as for cataract, but passed the knife behind the iris, and in doing so he opened the capsule of the lens. An iridectomy is then made by seizing a wide portion of the iris and corre- sponding retro-iritic connective tissue with a special forceps, 2()8 DISEASES OF THE EYE. one blade of which is passed behind these structures, whilst the other enters the anterior chamber, and' then the iris, etc., having been drawn out, the exposed portion is cut off. The partially, or completely, opaque lens, or a considerable portion of it, becomes evacuated during this proceeding; or, if not, the usual measures are taken to extract it. With this method, also, the pupil frequently closes again, and even more than one supplemen- tary iridectomy, or iridotomy, may be required, but must not be undertaken until all irritation subsides. The iridectomy, as above described, is now with advantage often replaced by a V shaped one, made with de Wecker's forceps-scissors. The late Mr. George Critchett's Method for the formation of a pupil in these cases consists in passing a discission needle, by a boring motion, through the lenticular capsule ; another needle is passed in close to the first, and then by separating one point from the other a rent is made in the centre. This is followed, generally, by the escape into the anterior chamber of a small quantity of cheesy lens matter. The latter is allowed to become gradually absorbed, and in the course of some wrecks the capsule closes again. The operation has to be repeated several times before a clear pupil is obtained, care being taken that all irri- tation from the previous operation has subsided before another is undertaken. Mode of Performing Enucleation of the Eyeball. — There are two chief methods : — 1. Bonnet's Method. An incision is made in the conjunctiva all round the cornea and about 6 mm. removed from the latter. The bulbar conjunctiva is separated from the globe freely in all directions with a scissors. With a strabismus hook each orbital muscle is caught up, and its tendon divided close to the sclero- tic. The globe can now often be dislocated forward by pressure of the margins of the lids backward, and is then held in the fingers of the left hand, while the optic nerve is divided with a strong scissors passed into the orbit from the median side. If the globe cannot be dislocated, it may be drawn forw^ard with a strong toothed forceps while the nerve is being divided. SYMPATHETIC OPHTHALMITIS. 269 2, The Vienna Method. The only instruments used in this operation are a strong, straight scissors, and a strong toothed forceps. The tendon of the internal rectus at its insertion, with the overlying conjunctiva, is seized in one grasp with the forceps, and so held until the conclusion of the operation. Immediately behind the forceps the tendon is divided with the scissors ; and now the forceps is holding merely the stump of the tendon ad- herent to the globe. Through the opening necessarily made at the same time in the conjunctiva one blade of the scissors is passed, and pushed on under the tendon of the inferior rectus muscle, which is then divided along with the overlying conjunctiva. In the same way the superior rectus is divided. The globe is now drawn well forward and rotated outward, the scissors passed into the orbit, the optic nerve felt for, and divided. With one or two strokes of the scissors the external rectus and the two obliques are divided close to the globe, and the operation is completed. This method is very rapid. It is not suited to any globe of which the walls are weak (fresh perforating injury, extreme staphyloma, etc.), for a good deal of pressure is exer- cised on the eyeball during its performance. Careful antiseptic precautions are to be employed in connec- tion with enucleation of the globe. Of these, I think, the most important is the use of a full stream of corrosive sublimate solution (1 in 5000) into the cavity of the orbit as soon as the eyeball is removed, the irrigation being maintained for several minutes. The interior of the orbit is to be then well covered with finely powdered iodoform, a piece of drainage tube placed in the outer canthus, so as to insure exit of any discharge which may form, and a wood-wool or other antiseptic pad applied with a bandage. The orbit should be similarly dressed every twenty- four hours. I have never seen the slightest trouble after enucleation of the eyeball, but some cases of meningitis following upon the operation, and which have proved fatal, are reported. There can be no reasonable doubt but that, in these instances, septic 270 DISEASES OF THE EYE. 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 antiseptic precautions above indicated. Occasionally, in ten days or longer after the operation, a granulation forms in the apex of the orbit and requires to be snipped off. To prevent this some surgeons unite the conjunc- tival opening with a suture after the eyeball has been removed. An artificial eye can usually be inserted after a fortnight, but should not be constantly worn for a month at least; as, until that period elapses, it is liable to cause irritation and conjunc- tivitis. Mode of Performing Resection of the Optic Nerve. — An opening is made into the conjunctiva about 3 mm. behind the insertion of the internal rectus muscle ; this muscle is laid bare, and two curved blunt strabismus hooks are inserted beneath it. The hooks are drawn in opposite directions, so that one is caught in the angle of insertion of the tendon with a tendency to roll the eye outward, while the other will draw the muscle forward out of the orbit. Near the latter hook a catgut thread is passed through muscle and conjunctiva, first from within outward, and then the opposite way. The muscle is now divided at a distance of at least 5 mm. from its insertion into the sclerotic, and the ends of the catgut thread are tied in a knot. A second thread is passed through the terminal stump of the muscle and similarly tied in a knot. The wound is now extended both toward the superior and inferior recti muscles, and a small, pointed, double hook is inserted into the sclerotic far back, in order to draw the globe forward and outward. A pair of scissors curved on the flat are inserted alongside the globe, and the optic nerve cut through as near the optic foramen as pos- sible. The posterior aspect of the globe can now be exposed to view by means of the double hook. The stump of the optic nerve remaining on the eyeball is then cut off near its insertion SYMPATHETIC OPHTHALMITIS. 271 into the sclerotic, the insertion of the oblique muscles divided, and the whole of the posterior circumference of the sclerotic bared by dissection. The eyeball is replaced, the wound closed by means of the catgut threads previously introduced, and, as a precaution against sanguineous exophthalmos, the eyelids are united by three sutures. CHAPTER XI. THE MOTIONS OP THE PUPIL IN HEALTH AND DISEASE. The Size of the Pupil in Health depends chiefly on the intensity of the light to which the eye is exposed, contracting when light falls into the eye and dilating in the shade. However defective vision may be, if quantitative perception of light remains, the reaction of the pupil, as a rule, takes place. There is no absolute Standard for the Physiological Size of the Pupil. The latter varies in diflferent healthy individuals, being in general smaller in elderly people than in youthful subjects, for with increasing age the energy of the sympathetic — the dilating nerve of the iris — is reduced, while there is sclerosis of the walls of the vessels of the iris and rigidity of its stroma. Persons with blue irides have, in general, smaller pupils than those with dark eyes, for in them more light reaches the retina, and hence the pupil-reflex is stronger. It has also been stated that hyperme- tropic eyes are apt to have small pupils, owing to the constant effort of accommodation, while in myopia, for the converse reason, the pupils are said to be wide ; but the observation is not generally accepted. The diameter of the pupil, when the accommodation is at rest, has been found* to vary between 2.44 and 5.82 mm., giving an average diameter of 4.14 mm. Contraction of the Pupil. — Contraction to light is a reflex motion, the optic nerve being the afferent nerve, and the third nerve the efferent nerve innervating the sphincter pupillae. It has been shown by a high authority f that there are special afferent fibres in the optic nerve for the pupil-reflex, distinct from those for vision, and that it is possible to dis- tinguish with the microscope these two kinds of nerve fibres from each other. The anatomical investigations of Meynert+ have shown that between *Woinow, " Ophthalmometrie," Vienna, 1871. t B. von Gudden, Sitznuysher. d. Munch. Ges. f. Morphof. it. Phi/sioL, 1886, i, p. 1. :j: Voin Gehirn der Siiugethiere, "Strieker's Handbuch," Leipzig, 1870. 272 THE PUPIL IN HEALTH AND DISEASE. 273 Fig. 101, the corpora quadrigemina and the centre for the third nerve run commu- nicating fibres (2, Fig. 101), which probably enable this reflex to take place. Owing to the semi -decussation of the fibres in the optic chiasma, the stimulus of light, when applied to one eye alone, passes up each tract with equal power to the corpora quadrigemina, and thence by Meynert's fibres to the centre for the third nerve (or rather to that portion of it which acts as a special centre for the sphincter pupillae), and from that point down the my- otic, or short ciliary, branches of this nerve to each ciliary ganglion, the ciliary nerves, and each sphincter iridis, caus- ing as active a contraction of the pupil in the non-illumi- nated eye (consensual con- traction) as in its fellow. It is probable, however,* that, in addition to this method of bringing about consensual contraction of the pupil, there is a communication, direct or indirect, between the centres for the third nerve of each side capable of effecting it."^ In no other way can the fact be ex- plained, that consensual con- traction of the pupil is main- tained, in cases of homony- mous hemianopsia. If, for instance (Fig. 101), there be a lesion of the right tractus opticus giving rise to left hemianopsia, the centre of the left third nerve alone can be primarily stimulated ; but, as both pupils act, a communication between the centres of the third nerves must exist. Merkel t believes that there is a direct anastomosis between these centres. But it must be stated that there is a good deal of divergence of opinion as to the path by which the pupil-reflex is brought about. Bechterew is N. Centre of third nerve. 1. Connection be- tween nuclei of third nerves. 2. Meynert's fibres. Q. Corpora quadrigemina. C. Chiasma. 0. Optic nerve. P. Myotic fibres of third nerve. L. Seat of Lesion. Arrows show path of im- pulse in lesion of right tract at L. * Lesser, " Die Pupillarbewegung ir iehung," Weisbaden, 1881, p. U. ■f- Grnefe-Siemisch Handbuch, vol. i. Physiologischer und Pathologiseher Be- 274 DISEASES OF THE EYE. of opinion that the centripetal pupillary fibres pass uncrossed from the chiasma directly to the gray matter surrounding the third ventricle, and thence backward to the pupillary nucleus of the oculo- motor nerve of their own sides respectively. Gudden made experiments which seemed to him to prove that the corpora quadrigemina had nothing to do with this path, and ascribed to the external geniculate body the part usually assigned to the corpora quadrigemina. Mendel's experiments ^ would lead to the view that it is the ganglion habenulge which is the centre for the pupillary reflex in animals, and in this he is largely supported by Darkschewitz, who holds that the pupillary fibres from the optic tract pass both into the pineal gland and the ganglion habenulae. According to Mendel the reflex path would be: Optic nerve, optic tract, to the ganglion habenulse of the same side, thence by the posterior commissure to the nucleus of the third nerve, and thence to the ciliary nerves. The reflex mobility of the pupil to light is tested, most commonly, for the purpose of deciding the existence, or otherwise, of posterior synechiae. The next most common object of the test, and the one with which we are here concerned, is to determine the sensitiveness 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 it must be remembered that the latter function may be wanting in certain diseased states and yet the pupil-reflex take place, or the pupil-reflex may be wanting and still perception of light be present. The test is best performed in diffuse daylight, with the patient's face directed toward the window, a distant object being looked at, and the eye which is not under examination being carefully excluded from the light. 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 80 on, until, after some further minute oscillations, it comes to a stand- still. The explanation for this phenomenon — which is termed Hippus — is, that each contraction of the pupil, by diminishing the supply of light to the retina, contains in itself the cause of the succeeding dilatation ; and, for the converse reason, each dilatation sets agoing the succeeding contraction, until at last equilibrium is attained. A comparison between the maximum of dilatation and maximum of contraction, along with the '^Nexiroloy. Centntlbf., 1890, p. 184. THE PUPIL IN HEALTH AND DISEASE. 275 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 through 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 pupil-contraction, which is associated with convergence or accommodation {vide infra), may not vitiate the experiment. The danger of a vitiation of the experiment by the reflex dilatation from the skin {vide infra), caused by the excluding hand, is insignificant in practice. 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 examining the pupils we have also to decide whether they be of equal size ; and, in order to avoid error through posterior synechias, the comparison should be made, with both eyes open, successively in two very different bright- nesses of light. Under normal conditions equality in size of the pupils will exist, not only with both eyes open, but also if one eye be shaded ; for the normal consensual pupil-reflex is equal to 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 dilBcult to decide. Finally, it should be noted whether the direct pupil-reflex is similar in all respects in each eye. In addition to the stimulus of light, the pupil- contracting centre is excited by, or simultaneously with, the effort of accommodation for near vision. The object of this contraction is to cut off rays falling on the peripheral portions of the lens, which latter are not curved in the change for accommodation to the same degree as is the centre of the lens. This contraction, however, is much more intimately connected with conver- gence of the visual lines than with the effort of accommodation. It has been shown* that the contraction increases with the effort of accommodation, but not proportionately to the distance of the fixation point from the eye ; andf that the pupils do not contract if accommo- dation be effected without convergence ; but that in convergence without accommodation contraction is observed. It has also been found that the contraction was proportional to the degree of convergence, and that in myopes of high degree contraction of the pupil takes place at the other side of the far point, where, of course, the accommodation does not come * Adamiik and Woinow, Archiv fur Ophthalinologle, xvii, pt. 1 IE. H. Weber, "De Motu iridis," Lipsiae, 1851. 276 DISEASES OF THE EYE. into play. Aubert * thinks there is probably a common centre for the three actions — convergence, accommodation, and pupil-contraction — a view supported by Priestley Smith f; and Henson and Viilckers J have found that in dogs, in the posterior part of the floor of the third ventricle, the centres for the branches to the ciliary muscle, the sphincter pupillae, and the rectus internus occur in close succession, and they think that this region may be regarded as the centre assumed by Aubert. The existence of such a centre has been placed beyond controversy by Eales's case| of paralysis of convergence and accommodation, and of the associated pupillary contraction. These three motions, then, are not dependent on each other, but are co-effects of one and the same cause, i. e , a stimulus applied to the centre for convergence, accommodation, and pupil-contraction. In examining the mobility of the pupils in a given case, the contrac- tion on convergence should not be omitted. If the patient be blind of both eyes, the observation can be made by calling on him to direct his eyes toward his own hand at about twelve inches distance. If both accommodative contraction and light reflex are wanting, a lesion in the course of the centrifugal pupil fibres is indicated, while if the light reaction alone is wanting, the lesion is in the course of the centripetal fibres. Dilatation of the Pupil. — The most reliable investigations || have dis- tinctly proved that there is no such muscle as the dilator pupillae. The dilatation of the pupil is, in all probability, largely the result of an inhibitory action of the sympathetic, a view maintained also by Gaskell^ and Jessop.*"^ The posterior limiting membrane of the iris is its only structure which is not thrown into folds when the pupil dilates (Fuchs), and therefore there can be little doubt but that it takes an active part in dilating the pupil, probably by reason of its elasticity. Yet, inasmuch as when the pupil is dilated from paralysis of the third nerve a further dilatation can be produced by atropine, it is probable that some other as yet unascertained dilating power resides in the iris. The mydriatic err long ciliary nerves, originating (Henson and Viilckers) in the front part *"Graefe und Saemisch Handbuch," ii, p. 669. t Ophthal. Hasp. Rep., Vol. ix, p. 32. \ Arch f. Ophthal., xxiv, pt. 1, p. 23. ^ Tvana. Ophthd. Soc, .Jan. 10, 1884. II Schwalbe, " Handbuch der Sinnesorgane :" Eversbiisch., " Berit-ht d. Ophthal Gesellsch.," 1884; Fuchs, (irtte/e's Archiv, xxxi, pt. 3, p. 39; Jessop, Proceed. Roy. Soc, 1886, p. 478. ^ Journ. of PhrjH., vii, 1, p. 38. "^ Proceed. Roy. Soc., 1886, p. 484. THE PUPIL IX HEALTH AND DISEASE. 277 of the floor of the aqueduct of Sylvius, pass to a region in the lower cervical and upper dorsal portion of the cord, called by Budge* the ciliospinal centre, and from thence pass out with the two first dorsal nerves, and by way of the rami communicates, to the sympathetic in the neck, and thence to the cavernous plexus, gasserian ganglion, ophthalmic division of the fifth nerve, nasal branch of this division, ganglionic branch of this nerve, ciliary ganglion, there joined by more branches from the cavernous plexus, and from thence by the short ciliary nerves reach the eye. The dilating nerve fibres are probably of twofold nature, muscular and vasomotor. The experiments of Grunhagen,t Salkowski,i Bonders, and Hamer, I Stellwag, 'I and F. Arlt, Jr.,*" indicate this, and that the centre for each kind of fibre is different, though both are situated in the medulla oblongata, and their fibres probably run the same course to the eye. The centre for the muscular fibres is called the oculo-pupillary centre. That the vasomotor fibres have a decided and independent influence in dilating the pupil has been shown by Rouget, *^ Schoeler,tt and others. It is not certain what the mechanism of this influence may be, but it probably consists in a diminution in volume of the iris, from antemia caused by contraction of the muscular coat of the vessels. While light is the only stimulus capable of bringing about a reflex contraction of the pupil, the pupil-dilating centre reacts to every sensitive stimulus, e. g., the prick of a pin or a pinch on the neck, galvanism applied to the leg, ji the tickling of a sensitive place in the region of the fifth nerve on the face, Vi etc., and Westphal !;|| observed dilatation on shouting loudly into the ear of a person under chloroform. Schiff and Foa *^^ found that in curarized 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. The centre for this reflex is probably in the medulla oblongata,*** but * "Ueber die Bewegungen der Iris," 1S55, -f Zeitschriftf. rat. Med., xxviii. Xlhid., xxix, p. 167. I Xederl. Tijaschr. v. Geneesh, 1864. Ij "Ueber Atropin," All. Wiener Med. Zeitung, 1872, p. 146. ^^ ArcTiiv.filr OphthaL, xv, i. ^^" Comptes rendus et Mem. de la Soe. de Biologic," 1856. ft " Experimentelle Beitrage zur Irisbewegung : " Inaug. Diis. Doipat. 1869. j j Arndt, Griesengera Archiv f. Psych., ii. |§ Hecker, " Tageblatt der 45 Versam. deutscher Xaturforscher in Leipzig," 1872. {Ill Virchnic's Archie, xxvii, p. 409. ^■[ " La pupilla come estesiometro." L'Imparziale, 1874. ^5^** Salkowski, loc. cit. 278 DISEASES OF THE EYE. inasmuch as it takes place if the cervical sympathetic be divided,* it is evident that all the dilating fibres do not run to the eye by way of the cervical sympathetic. Schiff, f indeed, thinks it probable that the gasserian ganglion receives pupil-dilating fibres from the sympathetic traversing the cavum tympani. Some psychical emotions produce dilatation of the pupil. The pupils of a cat in anger dilate, and those of a frightened child. In sleep, or when under the complete influence of an anaesthetic, the pupils are contracted, for then all psychical and sensitive stimuli are reduced to a minimum. Facts authorize 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 indi- vidual they be slight, his pupil is contracted ; if intense, it is dilated. Arndt j asserts that in delicate, nervous, excitable people the pupils are often much, and habitually, dilated. In addition to those already mentioned, there are causes for the dilata- tion 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, associated with those of other centres in the medulla oblongata, especially with those for respiration and uterine action. With every deep inspiration or expiration a considerable pupillary dilatation takes place, not identical with that slight dilatation occurring on each ordinary inspiration, and depending on variation of blood pressure, but due^ to simultaneous stimulation of the respiratory and pupil-dilating centres, by retention of carbonic acid gas in the blood. Raehlmann and Witowski|| have observed marked dilatation at the beginning of each labor pain, to be explained as an associated action of the neighboring centres for uterine movements and pupil-dilatation. Besides 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 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. This hippus has been aptly termed by Laqueur*y the Unrest of the Pupil, and is due to the ever vary- ing sensitive and psychical reflexes, which are thus constantly manifesting their influences on the pupil. *Vuljjiaii, Archiv de ji^y^iol., etc., de Brown- Sequard. Janvier, 1874. t '' Unteisuchungen zur Naturlehre," x, 1867, p. 423. J Archiv/. Psychiatrie, ii, p. 589. ^ SchiflF, loc. cit. tl Archiv f. Physiolofjie, 1878, p. 110. ^, Klin. Monatxhl.f. Aiiyeuhtilk., Dec, 1887. THE PUPIL IN HEALTH AND DISEASE. 279 The Fifth Nerve has been held by some to have an influence over the motions of the iris similar to that of the sympathetic. This is doubtless a mistaken view,* the effect on the pupil following section of the fifth within the cranium being due to paralysis of the sympathetic fibres con- tained in it, and not to the lesion of the proper fibres of the fifth nerve. Others t again have ascribed to the fifth nerve a direct influence over the contraction of the pupil ; but this is to be regarded as a reflex action merely, Merkel indeed having demonstrated % the existence of a direct fibrillar connection between the centres of the fifth and third nerves. Action of the Mydriatics on the Pupil. Atropine. — Inasmuch as a maximum mydriasis can only result from paralysis of the pupillary branches of the third nerve, combined with excitation of the pupillary branches of the sympathetic, and as atropine effects such a mydriasis, it is evident that it acts in the way indicated on these nerves.^ A. von Graefe proved || that the aqueous humor of an eye into which atropine has been instilled acts as a mydriatic when applied to another eye. Duhoisine, Hyoscy amine ^ and Daturine act similarly to atropine. Co- caine mydriasis seems 1[ to be induced merely by a local irritation of the endings of the sympathetic in the iris, both of the vaso-constrictor fibres and of the pupil inhibitory fibres. Strychnine and curare are not, strictly speaking, mydriatics, as they only indirectly affect the pupil ; the mydriasis observed in poisoning by these drugs being, according to Schiff ** and others, the result of the retention in the blood of carbonic acid gas. Action of the Myotics on the Pupil. Eserine (or Physostigmine). — This drug is in all respects a complete antagonist of atropine, ff paralyzing the peripheral endings of the sympathetic in the iris, and stimulating the endings of the branch of the third nerve in the sphincter pupillse. Pilocarpine and Muscarine act similarly, but not with the same energy. Nicotine, applied to the eye, is found to act like eserine. J J Morphium *" Leeser, loc. cit., pp. 46-48. I Griinhagen, Beil. Klin. Wochenschr., 1866, No. 24; Rogow, ZciUchr.f. rut. Med., Vol. xxix, p. 289. % '' Graefe und SEemiscli's Harnlbuch," i, p. 14U. § Hermann, " Lehrb. der exp. Toxicologic, '•' 1874. II Archiv.f. OphthaL, i, pt. 1, p. 462, foot-note. % Jessop, Proceed. Roy. Soc, p. 441, 1885. ^"^P/lUger's Archiv, 1871, p. 229. ttHarnack, Arch. f. exp. Pathol., ii, p. 307; A. Weber, Archiv f. OphthaL, xxii, pt. 2, p. 231. XX Rogow, Zeitschrift f. rat. Med., xxix, p. 1 ; Schur, Zeituchrift f. rat. Med., xxxi, p. 402. 280 DISEASES OF THE EYE. has an antagonistic effect to atropine, both as regards the pupil and the general nervous system, and is employed in cases of poisoning by atropine {vide p. 237). Chloroform in the first or excitation stage of ancesthesia, according to the investigations of Westphal, " Budin,t and Hirschberg. J stimulates the pupil dilating centre, and in the second stage gradually reduces the ex- citability of this centre, until, finally, it is completely paralyzed, so that no form of stimulation causes any dilatation. Following on this is a still further contraction to a pin-hole pupil, due to stimulation of the pupil- contracting centre. Should the inhalation of the anaesthetic be continued longer, a dilatation of the pupil, often sudden, takes place, and this indicates paralysis of the pupil contracting centre, and the most serious consequences for the life of the patient. The Size of the Pupil in Disease. — Myosis may be caused by a dis- eased process irritating the pupil-contracting centre or nerve-fibres (the Irritation Myosis of Leeser), or by one causing paralysis of the pupil- dilating centre or nerve-fibres (the Paralytic Myosis of Leeser), or by a combination of both. Either cause alone would produce a medium myosis ; a combination of the two would give a maximum myosis. Irritation Myosis, according to Leeser, is not usually increased by the stimulus of light, nor on convergence of the visual axes, nor does it diminish in the shade. Mydriatics dilate such a pupil widely ; myotics contract it ad maximum. In paralytic myosis the pupil reacts well to light and on convergence, but does not dilate on application of sensitive or psychical stimuli or with co-ordinated motions. Mydriatics dilate such a pupil only partially, while myotics contract it ad maximum. In maximum myosis every reaction is wanting, strong mydriatics alone producing a medium dilatation. Irritation myosis is found in : a. The early stages, at least, of all in- flammatory affections of the brain and its meninges, in simple, tubercular, and cerebro-spinal meningitis. When, in these diseases, the medium myosis gives place to mydriasis, the change is a serious prognostic sign,| indicating the stage of depression with paralysis of the third nerve, b. In cerebral apoplexy the pupil is at first contracted, according to Bert- hold, 1| who points out that this contraction is a diagnostic sign between apoplexy and embolism, in which latter the pupil is unaltered, c. In the early stages of intra-cranial tumors situated at the origin of the third nerve or in its course, d. At the beginning of an hysterical or of an * Virchntv's Archiv, xxvii, p. 409. f Gazette des Hopitaux, 1874, p. 910. X Berl. Klin. Wochenschr., 1876, p. 652. ^ Leeser, loc. cit., p. 82. || Berl. Klin. Wochenxchr., 1869, No. .39 THE PUPIL IN HEALTH AND DISEASE. 281 epileptic attack. - e. In tobacco amblyopia,! probably from stimulation of the pupil- contracting centre by the nicotine, /. In persons following certain trades, as the result of long-maintained effort of accommodation % (watchmakers, jewelers, etc.), the pupil-contracting centre being subject to an almost constant stimulus, g. As a reflex action in ciliary neurosis; consequently, in many diseased conditions of those parts of the eye sup- plied by the fifth nerve. Paralytic myosis occurs : In spinal lesions above the dorsal vertebrse, e. g.s injuries, and inflammations, especially of the chronic form. The contracted pupil occurring in gray degeneration of the posterior columns of the spinal cord has been long known as Spinal Myosis. In the simple form of this myosis the pupil has but a medium contraction, and reacts both to light and on convergence. This condition is found in the early stages alone, when the disease has attacked merely the cilio-spinal centre, or higher up, as far as the medulla oblongata ; later on, when Meynert's fibres become engaged, we have the Argyll-Robertson pupil. The very minute pupil, often seen in tabes dorsalis, is probably due to secondary contraction of the sphincter pupilla3.|| Argyll-Robertson was the first to point out,*[ that in tabes dorsalis the pupil, although contracted, and responding to light by further con- traction but slightly, or not at all, does become more contracted on convergence of the visual axes (or accommodation). He explained this phenomenon as being due to paralysis of the cilio-spinal nerves, which he therefore regarded as the nerves supplying the sphincter iridis. But Raehlmann points out** that the myosis and the motor phenomenon are not directly connected ; for it sometimes happens that pupils which do not react to light, and do contract on convergence, are not habitually contracted, and may even be somewhat dilated. The two symptoms are, no doubt, often present together in tabes. The myosis is a sign, and an important one, of disease of the posterior columns, while the defective reaction to light with retained contraction on convergence indicates disease at some distance from the spinal cord, namely, in Meynert's fibres ; and this is probably the correct explanation of the Argyll- Robertson symptom. Disease in Meynert's fibres, however (as also disease of the optic nerve), may be in direct connection with disease of *Wecker, "Graefe und Sjeiuisch's Handbuch," iv. fHirschler, Arch./. Ophthal., xviii, pt. 1. ^ Seiffert, Allgem. Zeitschrift fiir Psychieatrie, x, 185.3, p. 544. Ji Hempel, Archiv f. Ophthal., xxii, pt. 1. ^ Edin. Med. Journal, xiv, 1869, p. 669, and xv, ISrO, p. 487. ^^ Loc. cit., p. 7. 24 282 DISEASES OF THE EYE. the cord, Stilling having found* fibres passing directly from the optic tract into the eras cerebri. Some authorities regard myosis as one of the earliest symptoms of tabes, while others do not. Raehlmann also thinks that, perception of light being present, if the pupils do not react to light, while they do contract on convergence, the symptom is usually one of serious central disease. Paralytic myosis is also found in general paralysis of the insane. In acute mania the pupil is usually much dilated, and when this mydriasis is changed for myosis, approaching general paralysis may be prognosticated.! Myosis, following on irritation mydriasis, is also found in myelitis of the cervical portion of the cord. In bulbar paralysis, if paralytic myosis occurs, the disease is probably complicated with progressive muscular atrophy, or with sclerosis of the brain and spinal cord.i Hirschler states ^ that he has frequently noticed a contracted pupil in alcoholic amblyopia, due, probably, to an affection of the medulla oblongata, possibly fatty degeneration. Myosis may also be due to paralysis of the cervical sympathetic, resulting from injury, from pressure of an aneurism of the carotid, innominate, or aorta, or from pressure of enlarged lymphatic glands. In apoplexy of the pons Varolii myosis is present, but it is not yet certain whether it is an irritation myosis || or a paralytic myosis. *[ Mydriasis may be caused by a diseased process giving rise to irritation of the pupil-dilating centre or fibres, or by paralysis of the pupil-con- tracting centre or fibres. The former is termed Irritation (or Spasmodic) Mydriasis, and, according to Leeser, is characterized by a moderately dilated pupil, contracting somewhat to light and on convergence, but not dilating on sensitive or psychical stimuli ; easily dilated ad maximum by mydriatics, but with difficulty contracted ad maximum by myotics. The latter is called Paralytic Mydriasis, and in it there is a moderately dilated pupil, reacting to sensitive and psychical stimuli. The reaction to light and on convergence varies according to the seat of the lesion. If the lesion lie between the iris and the pupil-contracting centre, the direct and con- sensual reaction to light is wanting, as also the associated motion on * Bei'hujehe/t zu Zehender's Mon(if>ibl!itfer, xvii, i)p. 203-207. f Seiffert, loc. ctt. j Leeser, luc. fit., \^. 94. g Archivf. Ophthal., xvii, pt. 1, p. 229. II Larcher, " Pathol, de la protub. Annulaire, deux, tirage," p. 54. «[ Jiidell, Berl. Klin.Wochenach., 1872, No. 24, THE PUPIL IN HEALTH AND DISEASE. 283 convergence of the visual lines. But if the lesion lie between the retina and the pupil-contracting centre, the direct contraction to light is wanting, while the consensual contraction, and that on convergence, are retained. In either case the pupil can be dilated ad maximum by mydri- atics, but not contracted more than to medium size by myotics. Irritation of the pupil- dilating centre and paralysis of the pupil-con- tracting centre, existing simultaneously, give rise to maximum mydriasis. In it there is absolute immobility to stimuli of all kinds, except to strong myotics, which may bring the pupil back to the normal size. Irritation Mydriasis occurs: — a. In hyperemia of the cervical portion of the spinal cord and in spinal meningitis. 5. In the early stages of new growths in the cervical portion of the cord. c. In cases of intra- cranial tumor and other diseases causing high intracranial pressure, according to Raehlmann, although Leeser points out that these may also give rise to paralytic mydriasis, d. In the spinal irritation of chlorotic or anaemic people, after severe illness, etc. e. As a premonitory sign of tabes dorsalis. /. In cases of intestinal worms, owing to the stimulation of the sensitive nerves of the bowel, and sometimes in other forms of intestinal irritation, g. In psychical excitement, e. g., acute mania, melancholia, progressive paralysis of the insane (often then unilateral, with myosis in the other eye). Unilateral mydriasis occurring at short intervals, now in one eye and now in the other, is, according to von Graefe,* a premonitory sign of mental derangement. Von Graefe observed madness, in the form of manie des grandeurs, to come on some months after the occurrence of this symptom. Paralytic Mydriasis (Iridoplegia) may be due either to a paralysis of the pupil-contracting centre or as the result of the stimulus not being conducted from the retina to that centre. It may be found under the former circumstances : a. Sometimes in progressive paralysis, where at first there was myosis. b. In various diseased processes at the base of the brain affecting the centre of the third nerve, c. In a late stage of thrombosis of the cavernous sinus, f d. In orbital processes which cause pressure on the ciliary nerves, e. In glaucoma. /. In cases of intraocular tumors which have attained a certain size. In paralytic mydriasis, due to non-transmission of the stimulus of light to a healthy pupil-contracting centre and nerves, contraction of the pupil will take place only on convergence of the visual lines. The same con- dition of pupil will be found if the lesion lies in the course of Meynert's ^ Archiv f. Ojyhthal, iii, pt. 3, p. 350. fKnapp, Archivf. OpJithnl., xiv, pt. 1, p. 220. 284 DISEASES OF THE EYE. fibres, although vision may be normal. If the lesion lie in the centre of vision, or in the course of the fibres connecting this centre with the corpora quadrigemina, although absolute amaurosis exist, the reaction of the pupil to light will be perfect. Paralytic mydriasis, due to non-con- duction of light-stimulus, is found in most cases of optic atrophy. Professor Damsch has noticed* a marked increased of the hippus of the pupil in certain diseased states, namely, multiple sclerosis, acute meningitis, apoplectic attacks followed by secondary tremor and spasms of the paralyzed muscles, and in neurasthenia. He is inclined to liken the hippus in these cases to the increase of the tendon reflexes, while immobility of the pupil would be the homologue of loss of tendon-reflex. Yet he does not think an exclusively reflex origin for the exaggerated hippus can be adopted in these cases, as it continues to an abnormal degree even when all reflex irritation is avoided, and consequently he concludes that an increase of the physiological hippus must be included as a cause. * Neurolog. CentralbL, 1890, p. 258. CHAPTER XII. GLAUCOMA- The chief, and essential, symptom of this disease is Increased Intraocular Tension — increased hardness of the eyeball — due to over-fullness of the globe. There is Primary Glaucoma and Secondary Glaucoma. In primary glaucoma the increased tension comes on with- out any previous recognizable disease of the eye ; and it is with it we have mainly to-do in this chapter. In secondary glaucoma, the increased tension comes on in consequence of obvious antecedent disease in the eye. Primary Glaucoma. Of primary glaucoma, commonly called " glaucoma," there are two great kinds: the Non-inflammatory, Non-congestive, or Chronic Glaucoma ; and the Inflammatory, Congestive, or, more or less, Acute Glaucoma. In using the term '' inflam- matory " here, it is not to be supposed that acute glaucoma is an inflammation in the strict pathological sense of the term, or, if so, to but a slight extent. The term is employed rather on account of some symptoms which are present (pain, red- ness of the eyeball, lachrymation), and which we are wont to see with inflammations of the eye — symptoms which are wanting in chronic glaucoma. Increased intraocular tension, then, is the chief and * From yAxivKog, 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 conditions, and therefore is not characteristic of glaucoma. 285 286 DISEASES OF THE EYE. essential symptom of glaucoma, whatever form of it may come before us; although this increased tension may not be present in the same degree, or indeed at all, at every time. If the surgeon place the tips of his index fingers close together on a normal eyeball, and make gentle pressure with them alternately, he will observe that the eyeball pits slightly on this pressure, and that a sensation of fluctuation is given to the fingers. The amount of this pitting or fluctuation varies according to the degree to which the eyeball is filled with its humors, and also, to some extent, according to the thickness of the sclerotic coat, and is not precisely the same in every normal eye. The glaucomatous eyeball is felt to be more resistant, to be harder, than the normal globe. But there are eyes which have normally a low tension, i. e., below the average normal tension ; and others which have a tension somewhat above the average normal tension ; and, in eyes of the latter class, it is occasionally difiScult to decide whether or not the tension is abnormally high, especially if there happen to be symptoms which might be due to high ten- sion. If it be a question of one eye only, then a comparison of its tension with that of its fellow decides the matter, for the physiological tension is always the same in each eye. Some clinical experience is necessary before the surgeon can appreciate by palpation those degrees of tension which are just above or just below the normal, and no other method is equally satisfactory. Tonometers have, indeed, been invented for the purpose, but for ordinary use the educated fingers are to be preferred. For the purposes of clinical notation. Sir W. Bowman sug- gested some signs, which have been very generally adopted. Normal tension he indicated by the letter T, slight increase of tension = T -f 1, still higher tension = T -f 2, while T -\- 3 indicates stony hardness of the eyeball. In the same way, di- minished 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. But the application of these sym- GLAUCOMA. 287 bols to the varying degrees of tension depends very much upon the observer. "T + 2," for instance, will not always convey precisely the same idea to every surgeon. The other symptoms of glaucoma are largely due to the increased tension, but in chronic glaucoma there are by no means so many symptoms as in acute glaucoma. Let us now discuss these two great forms of primary glaucoma separately. And first as to Chronic, or Non-Inflammatory, Glaucoma (also known as Simple Glaucoma, as Simple Chronic Glaucoma, and as Chronic Non- Congestive Glaucoma). — Sijmj^toms. The Fig. 102 {Ed. Jaeger). iiii,-H sc, Sclerotic ; eh, Choroid ; r, Retina; of, Optic nerve; ca, Intervaginal space; v, Ex- ternal sheath of the optic nerve; e, Excavation of the papilla; M, Margin of the Excavation ; Ic, Lamina cribrosa. tension is raised. Sometimes the eye will be very hard (T + 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. The external appearance of the eye is usually quite normal, and the pupil reacts well to light. The anterior chamber is sometimes a little shallow. On examination with the ophthalmoscope the optic papilla is found to be " cupped." The optic papilla, being the weakest part of the ocular wall, is the first place to give way to the 288 DISEASES OF THE EYE. high tension ; and, after a time, it becomes depressed or cupped, the excavation being often deeper than the outer surface of the sclerotic, and the lamina cribrosa being pushed back (Fig. 102). This cupping of the papilla is a most important sign of glaucoma, and differs essentially in ap- pearance from the physiological cupping (vide p. 78), inasmuch as it occupies the entire area of the papilla, and has steep, not shelving, sides. As shown in Fig. 102, the walls of the ex- FiG. 103 {Ed. Jaeger). ■^ a, Arteries; v, Veins ; k. Bending ol ihe ve■^>el^ at margin of the papilla ; Vp, Vessels on the floor of the excavation ; z, Glaucomatous ring. cavation are often hollowed out, and the ophthalmoscopic effect of this is to give to the retinal vessels the appearance of being broken off at the margin of the papilla (Fig. 103), where they pass around the overhanging edge of the ex- cavation and become hidden by it, while on the floor of the excavation they reappear. .^ The presence of an excavation may be recognized ophthalmo- scopically in the examination by the indirect method, by means GLAUCOMA. 289 of lateral motions of the convex lens. It will be then 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. The phenomenon is ex- plained by the accompanying figure (Fig. 104). If o be the optical centre of the lens being used in the examination, and h and a two points lying one behind the other, the inverted images of these points will be situated at h' and a . The line a b' lies in the visual line of the observer ; and, if the lens be moved Fig. 104. upward a very little, so that the optical centre comes to o\ the inverted images of b and a will be moved to b'- and cr. If the observer has 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 downward, will best show the parallax. In the upright image the existence of an excavation may be ascertained by observing that a lens of a different 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 25 290 DISEASES OF THE EYE. 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 becomes atrophied from the pressure, and its consequent pallor serves to aid the diagnosis between this and physiological excavation. But we meet with cases in which the optic disc is cupped and pale, and in which the existence of increased tension is doubtful (vide p. 286). And here sometimes the diagnosis between glaucoma and primary atrophy of the optic nerve, with cupping of the disc, is one of the most difficult to be met with — indeed, it must some- times be regarded as impossible. The examination of the field of vision gives no help, for in each of these diseases it is liable to be contracted. Possibly the effect of a myotic on the intra- ocular pressure may assist to a decision, for it would not ma- terially influence normal tension, while it would reduce abnor- mally high tension. Also the fact that in glaucoma the L.M. is affected and the L.D. is almost normal, while in optic atrophy the reverse is apt to be found. Around the margin of the glaucomatous excavation, especially in chronic simple glaucoma, one usually sees the whitish appear- ance termed the glaucomatous ring (Fig. 103), which is said to be due to atrophy of the choroid from pressure. A pulsation of the arteries on the optic papilla may be often noted, or if not present may be easily produced by very slight pressure with the tip of a finger on the eyeball, because blood can only be forced into these vessels by a pressure greater than that opposed to it. In the normal eye there is no arterial pul- sation, — and slight pressure with the tip of the finger would not bring it on — for the tension of the coats of the vessels is greater than the intraocular tension ; and, therefore, the blood passes on in a continuous stream ; but, in the glaucomatous eye, the intra- ocular tension opposes so great an obstacle to the arterial flow that at the systole alone can it make its w^ay through. GLAUCOMA. 291 Arterial pulsation also occurs, although rarely, in exophthal- mic goitre (see Chap. XIX) and it occurs where the pressure in the arteries themselves is low (weak heart's action, etc.), although that in the vitreous chamber be normal. The acuteness of vision is diminished, and increasing dimness of sight is the only symptom of which the patient complains. Besides this, the field of vision becomes contracted, in conse- quence of interruption to the conduction of the retinal nerve- fibres from pressure on them at the margin of the depressed optic papilla. This contraction of the field must always be examined for by the recognized methods. It commences at the nasal side, as a rule ; while, at the same time, central vision is lowered, and later on the temporal portion of the field becomes contracted, and gradually absolute blindness is brought about. The Light-Sense in glaucoma is defective, both as regards L. M. and L. D., or else only as regards L. M., which is much greater than normal. The progress of the disease is extremely slow, extending often over several years, and ends in total blindness if un- treated. It usually attacks both eyes, but generally one of them long before its fellow. Sometimes chronic simple glaucoma, after a time, takes on the acute, or the sub-acute, form. Acute, or Inflammatory Glaucoma. (Also called Acute Con- gestive Glaucoma.) — In this form the increase of tension is always very marked. In addition to this, there are the follow- ing symptoms : — Diminished Depth of the Anterior Chamber, from pushing forward of the lens and iris. Diminution of the Refracting Power of the Eye, by reason of the nearer approach of the latter to a globular shape. Diminution of the Amplitude of Accommodation and Anaesthe- sia 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 peculiar " steamy " or " breathed-on " appearance, due to oedema of the corneal tis- sue and epithelium by infiltration into them of the intraocular 292 DISEASES OF THE EYE. fluids from high tension. A similar opacity of the cornea is sometimes seen in iritis anrl irido-choroiditis, and in interstitial keratitis. Indistinctness of the Pattern of the Iris, similarly due to oedema. Opacity of the Aqueous and Vitreous Humors. 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 oval, with its long axis vertical. The Episcleral Veins are large and tortuous, owing to the pressure on the vasse vorticos£e preventing the discharge by those channels of the choroidal venous blood, which must then pass off by the anterior ciliary veins. Subjective Appearances of Light and Color, and colored halos, or rainbows, around lamps and candles, are complained of. Similar appearances are sometimes experienced by persons suffer- ing from chronic conjunctivitis. A very marked symptom of acute glaucoma is Pain, both in the eye and radiating over the corresponding side of the head. This pain is often very violent. Vision is greatly affected, and the field of vision will be found contracted in cases of some standing. The optic papilla, when the media are sufficiently clear to admit of its being examined, is seen to be cupped if the disease has continued sufficiently long to bring about this change. In acute glaucoma we recognize certain Premonitory Symp- toms, viz. : Sudden diminution of the amplitude of accommo- dation, evidenced by the rapid onset or increase of presbyopia and the consequent necessity for the higher -j- glasses for near work, and the occasional appearance of colored halos around the flames of lamps or candles, with attacks of foggi- ness 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 with peri-orbital GLAUCOMA. 293 pains. Slight opacity of the aqueous humor and sluggishness of the pupil, with some dilatation, are present during an attack, but afterward the eye returns to its normal condition and remains so for weeks or months, until another similar attack comes on. Such a premonitory stage may last a year or longer, but cases also occur in which there is no premonitory stage. The onset of The True Glaucomatous Attack is usually at night. It is accompanied by violent pain radiating through the head from the eye, by pericorneal injection, chemosis, and lachrymation. The aqueous humor is cloudy, the anterior chamber shallow, the iris discolored, and the pupil dilated to medium size and of oval shape, the cornea " steamy " and anaesthetic. The patient frequently complains of subjec- tive sensations of light, and vision is very defective or may be quite wanting. Vomiting very frequently accompanies acute glaucoma, and has often led to errors of diagnosis, the patient's ailment having been taken to be a gastric disease, while the ocular symptoms were regarded as accidental coin- cidences, 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 come about. 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 still 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 humor will be found opaque, the optic papilla cupped, and an arterial pulsation may be discovered. At last there is no remission from the attack, the violent glauco- matous symptoms become permanent, and all vision is forever destroyed. 294 DISEASES OF THE EYE. Even when vision has been destroyed, the high tension con- tinues and gradually produces disorganization of the tissues of the eyeball (glaucomatous degeneration). The iris becomes atrophied, the lens becomes opaque, and the cornea frequently ulcerates, while hemorrhages are apt to occur in the anterior chamber. In time, the excessive intraocular tension causes staphylomatous bulging of the sclerotic in the ciliary region or further back, and, finally, such eyes may become the subjects of acute purulent choroiditis, and end in phthisis bulbi. Acute glaucoma almost always comes in both eyes, either at the same time, or with an interval, it may be of weeks, or of months. The reason why there is so marked a diflference between the symptoms and course of chronic and of acute glaucoma is that, in the former, the increase of tension is very gradual, and, therefore, the eye becomes accustomed to it, while in acute glaucoma 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 Fuhninans is the name given by von Graefe 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 of acute glaucoma greatly exaggerated, does not remit, and causes complete permanent destruction of vision in the course of a few hours. It is a rare form. 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 gradually becomes hard, the pupil dilated, the anterior chamber shallow, the aqueous humor opaque, while the cornea is " steamy " and aniesthetic, and the episcleral veins are distended. Oph- thalmoscopically the cupped disc and pulsating arteries may be seen where the opacities of the media permit. Vision sinks, and the field is contracted toward its nasal side. The progress of the disease is very slow, and in its course attacks of ciliary GLAUCOMA. 295 ueuralgia with greater increase of the tension, greater opacity of the aqueous humor, increase of the corneal opacity and anaes- thesia, and further dimness of vision, are experienced. These attacks pass off again 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 under the thirtieth year. It is not peculiar or more common to Fig. 105. Diagrammatic representation of normal condition. /. Augle of anterior chamber and ligamentum pectinatum. s. Canal of Schleium. p. Venous plexus of Leber. any one constitution or temperament. Anxiety, sorrow, and in- fluences in general which depress the spirits, have often been noticed to precede the onset of acute glaucoma. As regards the Pathology of Glaucoma, the theory which of late years has obtained most acceptation owes its origin to Max Knies* and Adolf Weber,t and is known as the Retention Theory. These observers ascertained that, in glaucomatous eyes, the periphery of the iris lies in contact with the periphery of the cornea (Figs. 105 and 106) in the region of the canal of * Von Graefe's Archiv, xxii, pt. 3, p. 163, and xxiii, pt. 2, p. 62. J Ibid., xxiii, pt. 1, p. 1. 296 DISEASES OF THE EYE. Schlemra, venous plexus, and liganaentum pectinatura. But this region and these tissues, having previously been proved by Leber* to be the ways of exit of the effete intraocular fluids, which flow to that point from the posterior part of the aqueous chamber through the pupil, AVeber and Knies concluded that the blocking of these passages by the close application of the iris caused glaucoma by preventing the effete fluids from escap- ing, and thus the disease was rendered one of retention, rather than of hypersecretion, as it had previously been considered to be. Weber believes that swelling of the ciliary processes, from one Fig. 106. Diagrammatic representation of glaucomatous condition. /' Obliterated angle of anterior chamber. cause or another, pushes the periphery of the iris forward and gives the starting-point for glaucoma. Brailey,t to a certain extent, adopts this view of Weber, but regards.! ^ chronic inflammation of the ciliary processes and periphery of the iris, with distention of the blood-vessels of these parts, to be the chief factor in the earliest history of the disease. Priestley Smith,§ too, adopts the retention theory, and holds */62d, xix, pt. 2, pp. 87-185. f Ophth. Hosp. Bep., x, p. 285. X Ibid., ix, p. 199, and x, pp. 14, 89, 93. ^. " On Glaucoma," 1879, Ophth. Hosp. Bep., x ; Trans. Internal. Med. Congress, 1881 ; Ophthalmic Review, July, 1887. " Pathology and Treat- ment of Glaucoma," London, 1891. GLAUCOMA. 297 that the main predisposing cause of primary glaucoma is an in- sufficient space between the margin of the lens and the structures which surround it ; and he attributes the greater liability of elderly people to the progressive increase in the size of the lens, which he has proved* to occur as life advances. In eyes in which the circumlental space is insufficient, by reason either of the original structure of the eye — and small eyeballs, as Priest- ley Smith has shown, as specially liable to primary glaucoma, a fact often demonstrated by the small size of the cornea in the eyes attacked — or of the enlargement 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 — the aqueous humor filters out more rapidly at the angle of the anterior chamber. As the contents of the chamber diminish, the lens and iris move forward toward the cornea. Now, in the normal eye, and especially in the youthful eye, this compensation is eflfected 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 already shallow, then any increased full- ness 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 forward 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 estab- lished. According to this explanation, then, the high tension is due to impeded escape of the intraocular fluid, not to hyper- secretion, and depends primarily rather upon an increase in the amount of blood in the eye than on an excess of the intraocular fluid. Mr. Priestley Smith considers that in chronic simple * Trans. Ophth. Soc. United Kingdom, iii, p. 79. 298 DISEASES OF THE EYE. glaucoma the predisposing causes are the same as in acute glau- coma, 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. Von Graefe* believed that a serous choroiditis lay at the root of the disease, which he thought was caused by exudation of serous fluid into the vitreous humor ; while Donders,t von Hip- pel and Grunhagen,J: and others, held that irritation of the fifth pair of nerves, governing the secretion of the intraocular fluids, gave rise to hypersecretion of those fluids. Others, again, held that changes in the sclerotic, rendering it rigid, and leading to some shrinking of it, caused the increased intraocular tension. Laqueur§ believes that some such sclerotic changes produce obstruction of the posterior ways of exit of the intraocular lymphatics, namely, those which pass out with the four vasse vorticosse, and that glaucoma depends largely upon this obstruc- tion. Treatment. — 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. This measure held an undisputed position as the sovereign remedy for the disease until a few years ago, and even yet has not suffered much from the competition of the operation of sclerotomy. To insure the success of an iridectomy for glaucoma, so far as possible, it is necessary : 1. That the incision should be peripheral, ^. 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 * Archivf. OphthaL, xv, pt. 3, p. 108, and elsewhere. f Ibid., ix, pt. 2, p. 215. Xlbid., xiv, pt. 3, xv, pt. 1, and xvi, pt. 1. 'i Von Graefe' s Archiv, xxvi, pt. 2. jl Archivf. Ophthal, iii, pt. 2, p. 456. GLAUCOMA. 299 ciliary body. 2. That the portion of iris removed should be wide, i.e., involving about one-fifth of the entire circum- ference of the iris (see p. 246 and Fig. 98). It is, moreover, important to withdraw the knife very slowly from the anterior chamber when the corneo-sclerotic section is complete, in order that the aqueous humor may flow off gradually, and the occurrence of an intraocular hemorrhage from the sudden reduction of tension be avoided. The portion of iris should be most carefully abscised, so that DO 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 operators prefer von Graefe's cataract knife for the performance of the opera- tion, but the ordinary lance-shaped iridectomy knife is the instrument usually employed. For the purpose of reducing the intraocular 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 unfavorable. Should an increase of tension occur on the day after the operation it is of no con- sequence, as it passes off again in the course of the next few succeeding 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 be worn until the anterior chamber is completely restored. I do not care for the use of eserine after a glaucoma operation, as I think it sometimes produces iritis. Von Graefe recommended that if, immediately after the iridectomy, the intraocular tension continue high, no bandage should be applied, as he believed it to do harm, but advised that the eyelids should 300 DISEASES OF THE EYE. simply be kept closed with a strip of court plaster. The pain for some time after the operation is considerable, but may be relieved by a hypodermic injection of morphia in the corresponding temple. Very occasionally, immediately after iridectomy, although the operation may have been faultlessly performed, the case takes what we call a "malignant" course. In these cases the lens seems to be violently pushed forward, blocking the wound, obliterating the angle of the anterior chamber, and preventing any fluid from escaping from the eye, so that very soon it is hard, or harder, than before. This complication seems to be caused by the retention of fluid behind the lens, and is more likely to occur in cases of chronic simple glau- coma than in the acute forms of the disease. Unless the method recommended by Adolf Weber for these cases be employed wdth success, all such eyes are inevitably lost, are apt to become very painful, and must often be excised. Weber* introduces a broad needle, or a Graefe's knife, through the sclerotic, 8 or 10 mm. behind the outer margin of the cornea, and gives the blade a quarter turn on its axis, so as to make the wound to gape. At the same time he applies a gradually increasing pressure, 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 maintained, with advantage, for a minute or somewhat longer. Mr. Priestley Smith speaks highly of this procedure, but I am happy to say I have not had the necessity to resort to it. As a rule, the more acute the form of glaucoma, and the earlier in the disease the iridectomy is performed, the more favorable is the prognosis in respect of the result which may be expected. The saving of normal vision can only be looked for in those cases, chiefly of acute form, where it has as yet *Von Graefe's Archiv, xxii, 1, p. 86. GLAUCOMA. 301 fallen but little, or not at all, below the normal, and where the contraction of the field has barely commenced. When the disease has interfered seriously with vision (of course I do not refer here to the enormous loss of sight immediately attendant upon an attack of acute glaucoma, for this is usually restored), we should not expect more than the retention of the status in quo. But our prognosis, even in this respect, should be most guarded, especially in chronic simple glaucoma, when the contraction of the field is found to have approached close to the fixation point, although central vision may be fairly good. Because, in such cases, while the iridectomy may prove successful so far as reduction of tension is con- cerned, yet the contraction of the field, i. e., the progress of the atrophy of the optic nerve, is often not arrested, and shortly afterward may be found to engulf the centre of vision. I go so far as to think that in such cases any opera- tion is liable rather to hasten than to retard the blindness, and I therefore never operate on them. It may, indeed, be stated, that while the result obtained from iridectomy in acute and subacute glaucoma, on the bases above laid down, can be regarded as amongst the most satisfactory in the whole range of ophthalmology, in chronic simple glau- coma iridectomy does not act with the same degree of success, and the prognosis should therefore be guarded in these cases. In cases of acute or subacute glaucoma, it has frequently been observed that shortly, even within a few hours, after the performance 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 crowding of the iris into the angle of the anterior chamber, in consequence of confinement in the dark room. It may here again (vide p. 238) be stated that the use of atropine, or of any other mydriatic, in an eye with a tendency to glaucoma, is liable to bring on an acute attack of the disease, and must be carefully avoided in such cases. If the tension be not relieved by the iridectomy, a supple- 302 DISEASES OF THE EYE. mental iridectomy may be performed after a time, and von Graefe recommended that it should be placed at the opposite side of the pupil from the first coloboma. The Mode of Action of the Operation is not clearly known. Von Graefe at one time believed it to act by diminution of the secreting surface of the intraocular fluids. De Wecker* and Stellwagt — even previously to the formulation by Knies and Weber of the retention theory of glaucoma already referred to — held that the cure depended, not on the removal of the portion of iris, but on the incision in the corneo-sclerotic margin, or rather on the nature of the cicatrix resulting from that incision. They maintained that this cicatrix was formed of tissue which admitted of a certain amount of fil- tration through it of the intraocular fluids, and that in this way the intraocular tension was kept down to the normal standard. This theory has gained support from that of Knies and Weber. Priestley Smith has satisfied himself that in a large number of successful iridectomies the success is due to a permanent corneo- scleral fistula — not merely a filtration cicatrix — having been formed. The same view is held by Treacher Collins,t who finds that this permanent gap is maintained by a prolapse of a fold of iris into the wound. The latter author, indeed, entirely and definitely discards the filtration-cicatrix theory, for which he considers there is no evidence. In those cases where a fistula, as described, is not formed by the operation, Treacher Collins con- siders that the obstruction 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 drag on the iris, incident on the iridectomy being sufficient to dislodge the periphery of an iris which has only recently come into apposi- tion with the cornea. *Bericht der Ophihal. Gesellsch. zu Heidelberg, 1869. J Der Intraoculare Bruck, etc. Vienna, 1868. t Roy. Loud. Ophthal Hosp. Rep., Dec, 1891. GLAUCOMA. 303 De Wecker, Stellwag, * and Quaglinof sought to produce the corneo-scleral filtration-cicatrix without the removal of a portion of iris. The peripheral position of the wound, however, ren- dered the proceeding difficult or impossible, owing to the ten- dency to prolapse of the iris which necessarily existed. The introduction of eserine into ophthalmic practice at last enabled de Wecker to place the operation on a surer footing, as the myosis produced by instillation of a solution of this drug into the eye insured the operator, to a great extent, against the danger of prolapse of the iris, and hence Sclerotomy, as the operation is called, has come to be cultivated as a method for the relief of glaucoma, and has proved useful as such. It has hitherto been employed more in chronic simple glaucoma, a form in which, as I have stated, iridectomy is less satisfactory than in acute or subacute glaucoma. Care must be taken that the pupil is contracted to pinhole size or nearly so, when the operation is about to be performed, as otherwise the danger of prolapse of the iris is very great. In those cases where eserine will not produce a sufficient myosis, sclerotomy should certainly not be performed. Priestley Smith and Treacher Collins explain the cure by sclerotomy in the same way as they do that by iridectomy. The instrument usad for performing the operation is von Graefe's cataract knife. A speculum having been applied and the eyeball fixed, the point of the knife is entered into the anterior chamber ^^*c '* through the corneo-sclerotic margin at a point of its circumference corresponding to that selected for the puncture in cata- ract extraction, but 1 mm. removed from the corneal margin, as represented at a in Fig. 107. The counter-puncture is made at a point (h) corre- * Bericht der Ophthal. Gesellsch. zu Heidelberg, 1871; Chirurgie Oculaire, p. 212. Paris, 1879. t Annali di Ophthalmologia, i, pt. 2, p. 200, 1871. 304 DISEASES OF THE EYE. spending to this, at the other side of the anterior chamber. With a sawing motion of the knife the section is enlarged upward, until only a bridge of tissue, about 3 mm. broad, remains at c, and this is left undivided, the better to guard against prolapse of the iris. The knife is now slowly withdrawn from the eye, care having been first taken that the aqueous humor is thoroughly evacuated, which can be effected by tilting the edge of the knife slightly forward, so as to make the lips of the wound gape somewhat. If the pupil be quite round at the conclusion of the operation, the bandage may be applied, a drop of solution of eserine having been first instilled. But if the pupil be oval or of other irregular shape, a tendency to prolapse of the iris is indicated, and the hard rubber or silver spatula should be introduced into the anterior chamber, to restore the pupil to its normal shape by gentle pushing of the iris. If there be an actual prolapse of the iris, an attempt may be made to repose it with the spatula, but should this not prove satisfactory, the prolapse is to be abscised with scissors, thus turning the sclerotomy into an iridectomy. The Treatment of Glaucoma by Myotics. — Eserine and pilocar- pine as eye-drops in two per cent, solutions often have the power of reducing glaucomatous tension. This power 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 myotic does not contract the pupil greatly 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 myotic instilled a few times. In acute glaucoma of the ordinary type, the use of a myotic in the premonitory stage will often postpone the true glaucomatous attack, and even sometimes relieve the latter for the time, but the myotic treat- ment cannot produce a radical cure, and it should only be used to preserve the health of the eye until the operation is per- formed. In chronic simple glaucoma, also, myotics bring down the tension if they contract the pupil, and may be used in those cases where the patient will not submit to an operation, or GLAUCOMA. 305 where an operation in the fellow eye has not resulted satisfac- torily, or where an operation is contraindicated by a very con- tracted field. The anti glaucomatous action of the myotic only lasts so long as the pupil is contracted, and if the pupil cannot be contracted no such action is to be looked for. In the myotic treatment of glaucoma, Priestley Smith recom- mends the combination of cocaine with the myotic, in such pro- portions (say, about 4- per cent, of cocaine to one per cent, of the myotic) that the myotic will have the mastery over the pupil. For although, like every dilator of the pupil when used alone, cocaine may promote high tension, yet as it has the powers, invaluable in glaucoma, of contracting the ciliary blood-vessels and of diminishing the sensibility of the ciliary nerves, and when used in the foregoing manner the advantage of each drug may be obtained without any of the disadvantages of either. It may be here once more stated that while myotics possess the power of reducing glaucomatous tension, atropine and all mydriatics used alone 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 too high. Treatment of Painful Blind Glaucomatous Eyes. — Eyes blind of acute glaucoma may, as I have stated, continue to be painful, and may in this way render the patient's life very miserable. Iridectomy is very commonly performed to relieve the pain, although all hope of restoration of sight is lost, but the operation sometimes fails in its object. Neurectomy (Chap. X, p. 270) seems to offer a more certain result, and, of course, enucleation or evisceration would have the same efiect. 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 different diseased states which are liable to become complicated with glaucomatous tension, but it should be clearly understood that in almost every instance the immediate 26 306 DISEASES OF THE EYE. 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 sec- ondary glaucoma : — a. Complete Posterior, or Ring Synechia {vide p. 236). The iris, being pushed forward by the aqueous humor pent up behind it 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 relieves the high tension here. b. Perforating Wounds or Ulcers of the Cornea, followed by incarceration of the iris in the resulting cicatrix. The iris being drawn tautly toward the cornea, a large portion, or the whole, of the filtration angle may be closed by it. An iridec- tomy is indicated. Lang divides anterior synechise by means of his twin knives. c. Dislocation of the Crystalline Lens into the Anterior Chamber. Here the normal flow of the intraocular fluids through the pupil (vide p. 296), on its way to 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 its periphery, which is unsupported by the lens, against the periphery of the cornea, and in this way the angle of the anterior chamber is closed. Here 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 humor, drives the root of the iris forward against the cornea at that place, while in other parts of the cir- cumference the displaced vitreous acts in the same way. In these cases, too, the lens must be removed. e. Injury of the Crystalline Lens (vide Chap. XIII). The swell- ing lens pushes the iris forward against the angle of the anterior chamber. Evacuation of the swelling lens should be performed. J. After Cataract Extraction. For explanation of this see Chap. XIII. GLAUCOMA. 307 g. Intraocular Tumors (vide p. 257). The growth of the tumor gives rise to a transudation of serum from the choroid, which detaches the retina, and after a time pushes the lens, the ciliary processes, and the iris forward, and thus closes the filtra- tion angle. h. Serous-Cyclitis, or Iritis. Here the filtration angle is not closed. Mr. Priestley Smith thinks that the increased tension is due to diminished filtration-power of the eye, and perhaps by tissue changes around the filtration angle. Another, and very peculiar, form of secondary glaucoma is: — Hemorrhagic Glaucoma. — Retinal hemorrhages of the ordi- nary type are sometimes followed, a few weeks later, by increased intraocular 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, so far as I am aware, been ofl^ered. When such a glaucoma has become pronounced, it is not usually possible to distinguish it from a primary form of the disease. Treatment. — Iridectomy in hemorrhagic glaucoma is more likely to do harm than good, the operation being almost inva- riably followed by fresh intraocular hemorrhages and by a further increase of tension. Sclerotomy is said by some to act with fairly good results in hemorrhagic glaucoma. The myotic treatment is powerless. Congenital Hydrophthalmos, also known as Buphthalmos, and Cornea Globosa, is a disease of early childhood, of which the incipient stages are believed to be intra-uteriue. The cornea becomes enormously enlarged in diameter, the anterior chamber deep, the iris trembling, and the sclerotic thinned. Increase of tension, often attended with severe pain, and cupping of the optic papilla are usually pres- ent. The disease is regarded as a secondary glaucoma, although 308 DISEASES OF THE EYE. it is by no means certain that it should not rather be consid- ered as a form of primary glaucoma occurring in young children. Treatment. — Iridectomy and sclerotomy are alike followed by disastrous results in this disease. The myotic treatment is the only one applicable, and in a few cases it arrests the disease. CHAPTER XIII. DISEASES OP THE CRYSTALLINE LENS. Cataract, by which is meant an opacity of the lens, may be said to be the only disease of this part of the eye. Cataract may be complete, i. e., occupying in its final stage the whole, or nearly the whole, of the lens ; or partial, i. e., 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 commencing or incipient senile cataract, the opacity is found in the cortical layers of the lens, especially at its equator, and in the latter position can often only be detected with transmitted light from the ophthalmoscope mirror, or with oblique light, even when the pupil is dilated wdth atropine. This opacity takes the form of lines, or of triangular sectors of which the bases are toward the equator of the lens, while the apices are toward its centre. These lines and sectors look black with transmitted light, but gray with oblique light, and between them clear lens substance is present. Or, incipient cataract may first appear as a diff*use opacity in the layers sur- rounding the nucleus of the lens. Or, the opacity may com- mence both near the equator and around the nucleus at about the same time. Or, again, the opacity may in the beginning be disseminated through the cortex in the form of flocculi, dots, and lines. In some cataracts, in a very incipient stage, 309 310 DISEASES OF THE EYE. there are no absolute opacities; but, with weak transmitted light, i e., from a plane 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 a little later on true opaci- ties 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 cataractous, although it is usually sclerosed. 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 non-cataractous lens, as seen with a dilated pupil or with focal illumination, a peculiar smoky appearance, which is often mistaken by inexperienced persons for cataract; but examination with transmitted light will show that there is no 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 grayish white. As a rule, the most peripheral layers of the cortex are the last to become opaque. Ac- cording as the lens becomes opaque, it swells somewhat, and the anterior chamber, consequently, 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 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. If the whole cortical substance be opaque, the thickness of the capsule alone will intervene between the pupillary margin and the opacity. In addition to this ex- amination with the focal light, the pupil should be dilated, and the lens examined by transmitted light from the ophthal- moscope mirror, when a completely opaque cataract should per- mit of no red reflection being obtained in any direction from the fundus oculi. As soon as the whole of the cortical substance has become THE CRYSTALLINE LENS. 311 opaque, the swelling of the lens begins to subside, and the anterior chamber finally regains its normal depth. If there be no glitter- ing sectors in the cortex, the cataract is now " mature," or " ripe ' for operation, i. e., if an extraction operation be now undertaken, it is possible to deliver the lens in its entirety ; whereas, prior to this stage, some cortical substance would have been liable to adhere to the capsule, and be left behind. But a cataract is immature, despite the absence of shadow from the iris, 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 faceted. In such a lens there are thin, transparent flakes, as well as opaque flakes, close beneath the capsule ; and, if extraction be undertaken, the former are very apt to remain within the eye in spite of every effort to remove them. A few months later the sectors lose their sharp contour, break down, and finally disappear. We can then depend upon the exit of the whole cataract. Yet I will not deny that in persons over sixty years of age, in whom the nucleus is usually large, many a cataract can be completely removed which does not quite come up to the standard of maturity just laid down, and at that time of life I would not hesitate to operate, without waiting for absolute maturity, if the patient were materially incommoded for want of sight. The foregoing is the most common course of events in the progress of a senile cataract, but there is a rather rare 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, but 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. After the stage of maturity a cataract gradually goes on to be hypermature. 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 312 DISEASES OF THE EYE. 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 sur- face of the anterior capsule, which result in a thickening of the capsule. In a Morgagnian cataract the fluid cortex finally under- goes absorption, and the anterior and posterior capsules come in contact (cataracta membranacea). The investigations of Priestley Smith* have shown that a diminished rate of growth of the lens precedes the formation of cataract ; and it is held that the cataractous process in the senile lens is the result, in the first instance, of a rapid sclerosis and shrinking 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 accommodate themselves, and then the fibrillse of these layers become separated somewhat from each other, and fluid collects in the interspaces. This fluid it is which causes the 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 it is this which causes the swelling of the lens already referred to. When the whole cortex has become opaque, the fluid contents begin to diminish and the lens returns to its normal size. Senile cataract, then, is entirely a local process, and is not dependent on any disordered state of the general health. The dimensions of the nucleus vary a good deal. In some cataracts it is very 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 throughout. The size of the nucleus can be estimated pretty accurately by the extent and intensity of the yellowish * Trans. Ophthal. Soc, 1883, p. 79. THE CRYSTALLINE LENS. 313 or brownish reflection, which is obtainable by focal illumination out of 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; conse- quently, 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. Although the starting-point of cat- aract in children and young adults cannot be a shrinking of the nucleus, as there is none, yet the opacity is, no doubt, due to the taking up of fluid by the lens. The Symptoms to which senile cataract gives rise consist, in the earliest stages, in the appearance of motes before the eyes and of monocular polyopia. Motes are complained of also in disease of the vitreous humor, but in those ca^ies they float over a large portion of the field of vision, while in commencing cata- ract they occupy always the same relative position in the field. The polyopia is the result of irregular refraction in the media, which causes many images of the objects looked at to be formed on the retina. This symptom seems to annoy the patients, more especially in the evening, when they look at gas or candle flames, the moon, etc. It is often complained of before there is any actual opacity in the lens, at a time when only the clefts filled with fluid between the fibrillse can first be detected with weak transmitted light, as dark lines vanishing and reappearing ac- cording as the incidence of the light is altered. Gradually, as the opacity of the lens extends to other parts of it, the acuteness of vision becomes aflfected, 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 27 314 DISEASES OF THE EYE. good deal so, 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 for this is that in the dusk the pupil is di- lated, 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 confined 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 pleasant to the patient. But, according as the lens becomes more and more opaque, the acuteness of vision is reduced, until, finally, even large objects cannot be discerned, and only quantitative perception of light is left. Some cataracts, when quite ripe, still admit of finger-counting at a few feet. In advanced stages of the disease, as the opacities occupy a great portion of or the entire cortex, they are easily recognized even by ordinary daylight, often giving a grayish appearance to the pupil. Inflammatory exudation 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, disorganization of the iris, etc. The length of time occupied by the ripening of a cataract varies, in different cases, from a few months to many years. In the very old 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 which the cortex around the nucleus is likewise implicated at an early period. All examinations as to the condition of the lens are rendered easier and more conclusive if the pupil be previously dilated with atropine, but the tension of the eye should be ascertained before atropine is instilled, lest glaucoma or a tendency to it be present. Treatment. — No external local applications nor internal medicines are of any avail in the treatment of cataract at any stage. Kemoval of the cataract from the eye by operation is the only cure for blindness caused by it. THE CRYSTALLINE LENS. 315 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, an emmetropic eye is liable to become slightly myopic, and then low concave glasses for distant vision will be found of service ; while for reading, stenop^eic glasses often give good results. Dilatation of the pupil with atropine is in many cases of the greatest benefit, especially where the nucleus is much more opaque than the cortical portion, but sometimes the diff"usion of light resulting is most distressing to the patient, and greater impairment and confusion of vision are produced, and for this reason care in the prescription of atropine is demanded. Patients with incipient or advancing cataract may, with immunity, 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 use their eyes to the best advantage. The truly distressing period in the progress of cataract, when both eyes are aflfected, 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 occur- rence of maturity or of that degree of maturity which is deemed requisite for successful removal. This is often a lengthened time ; it may be months or years. Fortunately, in many instances one cataract is much more advanced than that in the other eye, and then no such trial need be gone through. Artifieial Ripening. — In order to hasten the maturity of a cataract, puncture of its anterior capsule has been proposed and practiced with success, but has not been generally adopted, from the fear that it might set up iritis, and produce increased tension from excessive swelling of the cataract. Forster* effects artificial ripening by performing an iridectomy, which "^Archives of Ophthalmology, xi, pt. 3, p. 349. 316 DISEASES OF THE EYE. can afterward be utilized for the extractiou. This in itself often expedites the ripening, probably by disturbing the arrange- ment of the lens-fibres when the aqueous humor flows off, and Forster promotes the disturbance by gently rubbing or stroking the lens through the cornea, immediately after the iridectomy, with the angle of a strabismus hook. This same massage of the crystalline lens may be employed with good result after simple tapping of the aqueous humor without iridectomy. Soon after this a rapid increase in the opacity is often noticed, so that in from four to eight weeks extraction can be undertaken. The difficulty of this rubbing or massage of the lens lies in the estimation of the pressure to be applied, for if it be excessive the zonula may easily be ruptured, with the result of loss of vitreous when the extraction comes to be performed. The best results are obtained in cases of cataract with a firm and some- what opaque nucleus, and where a certain amount of opacity already exists in the anterior cortical substance. I occasionally employ the method, and with satisfactory results, but some operators have seen iritis follow the proceeding. The question whether the cataract in one eye should be extracted until both are blind is often asked by patients. The answer is: A patient with one mature cataract, and the other progressing toward 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 other, it is often advisable to operate for the purpose of increasing the binocular field of vision. Complete Cataract of Young People. — The spontaneous occur- rence of total cataract in the youthful lens is of rare occurrence, and its pathogenesis is still unknown. Treatment — Discission. Diabetic Cataract. — This is a complete opacity of the crystal- line lens occurring in diabetes, and due to disturbed nutrition. The cataract does not differ in appearance or consistency from other cataracts, according to the time of life of the patient. Treatment and Prognosis. — Contrary to a very general opinion, THE CRYSTALLINE LENS. 317 these cases are favorable for extraction operatious. I have operated on several cases of this kind, and always with success save once, when the eye was lost by intraocular hemorrhage, and I have also seen such cases operated on successfully by others. There is no other method of restoring sight to these patients, who often live a long time. But some ophthalmic sur- geons of distinction have informed me that, occasionally, patients operated on for diabetic cataract die of coma within about a fort- night or so after the operation ; and they seemed to think that this was not diabetic coma of the ordinary kind, but coma caused in some way by the nervous system being upset by the operation. Complete Congenital Cataract— Children are sometimes born with crystalline lenses opaque in all their layers, while the other tissues of the eye are healthy. With congenital cataract, defects of the choroid or retina, or congenital amblyopia without ophthal- moscopic appearances, are also sometimes present, and these are usually indicated by nystagmus. Treatment. — Discission. Partial Cataracts. These are nearly all congenital. Central Lental Cataract. — This is a congenital and usually non- progressive 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 form of cataract in children. It usually is present in both eyes, but it has been seen in one eye only. In it the very centre of the lens is clear (Fig. 108) > while around this is a cataractous layer or zone, and out- Fig. side that again the peripheral layers are transparent. Most of these cases are non-progressive, but, occasionally, the whole lens does become opaque, and usually then there have been previously some slight opacities in the otherwise clear cortical layers. With oblique illumination the cortical layers of the lens are 318 DISEASES OF THE EYE. seen to be clear, while toward the centre of the lens a uniform gray 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 be seen 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 margin of the disc is either of the same degree of darkness as its centre or but little darker, and this point 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 its opacity must be darker than its margin. It is probable that lamellar cataract is due to some passing disturbance of nutrition occurring at the time the affected layers of the lens are being laid down. The subjects of it are usually rickety, as shown by the irregular and imperfect development of the teeth, and in rachitic alterations in the bones of the skull. Convulsions during infancy, in these patients, are common. The Treatment of central lental cataract and of zonular cata- ract is similar, and consists in either discission or iridectomy. 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 stenopseic slit, is increased in a satisfactory degree. When the improvement is but slight, the breaking up of the lens with a needle is indicated. The advantage of iridectomy over discission, when the former can be adopted, is, that no spectacles are afterward required, and that the power of accommodation is retained. Congenital cataracts may be needled any time after dentition is completed. Anterior Polar, or Pyramidal, Cataract may be either con- genital or acquired. In the former case it must be referred to some inflammatory 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 THE CRYSTALLINE LENS. 319 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. After birth a perforating ulcer of the cornea is a necessary precursor of it, but the ulcer need not be central (p. 107). This contact with an inflamed and ulcerating cornea may lead to subcapsular cell- proliferation at that portion of the capsule which is exposed in the pupillary area. No Treatment is required, as vision is not aflfected. Fusiform, or Spindle-shaped, Cataract is also congenital, and is rare. It consists in an axial opacity extending from pole to pole, and may be combined with central or lamellar opacity. The foregoing forms of cataract, with the exception, perhaps, of the pyramidal or anterior polar cataract, are primary ; that is to say, they are not dependent on, or the result of, disease in other parts of the eye. But the fact has to be recognized that some diseased states of the eye give rise to Secondary Cataract. Of this a partial kind is Posterior Polar Cataract. — 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 choroiditis, retinitis pigmentosa, or diseased vitreous humor. 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 upon contact of the lens with inflammatory products in the eye, e. g., where false mem- branes have been produced by inflammation in the uveal tract. 320 DISEASES OF THE EYE. It is sometimes then called Cataracta Accreta, when the iris or ciliary processes are adherent to it. Cataract is also caused by- detachment of the retina, intraocular tumor, absolute glaucoma, etc. The reason of this is, that the lens, in these cases, imbibes abnormal nutrient fluid from the diseased tissues with which it is in contact. Such cataracts often undergo a further degeneration, and be- come calcareous. Calcareous cataracts are easily recognized 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 terra *' 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. This will be referred to again further on, and is not to be classed with the conditions dealt with in this paragraph. Capsular Cataract means 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 injury which opens the capsule of the lens is liable to cause cataract, by reason of the admission of some of the sur- rounding fluids to the lenticular substance. 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. But blows upon the eye, without any perforating wound, also, although rarely, produce cataract. In these^latter THE CRYSTALLINE LENS. 321 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 neighborhood of the opening becomes opaque, swells, and protrudes, as a gray, fluffy- looking mass, through the opening and into the anterior chamber, where it breaks up, dissolves, and becomes absorbed. It is im- mediately followed by other portions of the lens which have be- come cataractous, until, gradually, the whole lens may have disappeared, and the pupil again become black. Dr. Marcus Gunn suggests* that the explanation of the solution of the cat- aract in the anterior chamber consists in the fact that globulin is normally soluble in a weak solution of chloride of sodium, such as we have in the fluid of the anterior chamber. The ab- sorption of a traumatic cataract takes many weeks, and ulti- mately the eye sees well, if a suitable convex lens be put before it. But the course of events just sketched is the most favorable one, and is hardly likely to take place in a case which is wholly untreated. In the first place, the swelling of the lens — especially if it be rapid, in consequence of a wide opening in the capsule — is liable to irritate the iris and to cause iritis, or to push the periphery of the iris forward against the periphery of the cornea, block the angle of the anterior chamber, and cause secondary glaucoma (p. 306). Moreover, violent plastic or purulent uveitis may come on, as the consequence of the introduction of infective matter on the perforating object, or foreign body, which causes the cataract. Where this occurs, the case enters into 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 any absorption process, but simply remain station- ary, or in the course of years undergo secondary changes * Ophthalmic Review, 1889, p. 235. 322 DISEASES OF THE EYE. similar to those which occur in senile cataract. In these in- stances the trauma is usually a blow on the eye, not a perforat- ing 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 ; and, in addition to this, the rupture in many of these cases is probably at the equator of the lens, where the aqueous would not readily get access to the lenticular substance. Where the cataract is produced by a small, foreign body flying through the cornea and into the lens, it is a matter of impor- tance, 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 cataractous 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 it must be remembered that in these traumatic cataracts there are often glittering sectors in their deep parts, which may readily be mistaken for a metallic foreign body. Treatment. — The pupil should be kept dilated with atropine, in order to draw the iris out of the way of the swelling lens matter; and nothing more is necessary if complications do not arise. But should iritis, or high tension, come on — and the surgeon must constantly test the tension — it is important, with- out 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 for these inflam- mations. the crystalline lens. 323 Operations for Cataract. With regard to the State of Health of the Patient about to be operated on, it is desirable, as in every operation, that it should be good. Still, 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 experi- ence, I have not found serious disease of the heart, lungs, and liver, even when they all existed in the same individual, any impediment to a successful operation. Diabetes is no contra- indication, and even in the presence of Bright's disease I have operated successfully. Very advanced years form no obstacle. I have frequently operated for cataract on persons over eighty years of age, and always with success. The State of the Eye itself should be carefully investigated prior to proposing or undertaking an operation for cataract, and is a much more important matter than the general health. Above all things, it is to be determined whether there be intra- ocular complications which would neutralize the result of a successful operation, such as detachment of the retina, dissemi- nated choroiditis, atrophy of the optic nerve, etc. The examina- tion of the eye in question before the lens has become opaque, if the surgeon have had that opportunity, will be the most reliable basis upon which to go, 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 other eye, if its lens be clear, may help in determining the point, in so far as those intraocular diseases are concerned which are apt to be binocular. Again, the condition 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 intraocular mischief. It cannot be con- founded 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 percep- 324 DISEASES OF THE EYE. tion of light should be present, so that the light of a candle sonoe two metres distant may be distinguished. In less dense cataracts fingers may he counted at 1 ra. or 1.5 m. when full maturity has been attained. The field of vision must be examined by means of the " projection of light," i.e., a lighted candle held in differ- ent parts of the field should be recognized 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 ex- amination can also be 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. In cases of very old un- complicated cataract, the patients often project the light in one direction, no matter where it may come from. A certain degree of intelligence on the part of the patient is required for this test. By the foregoing means most intraocular complications of a serious nature can be detected, but there is at least one against which I know of no safeguard, namely, a small circumscribed spot of choroido-retinal degeneration at the macula lutea (central senile choroiditis). After removal of a cataract from an eye aflfected in this way, the patient's vision is so much improved as to enable him to go about alone, but reading will still remain an impossibility for him. The Cornea should be Examined. — Such corneal opacities as would seriously compromise vision may contraindicate the opera- tion ; but slighter opacities, discernible only with oblique illu- mination, would merely diminish the future acuteness of vision, and would require a corresponding prognosis to be given before operation. The Condition of the Appendages of the Eye, too, must be ex- amined. Should there be any conjunctivitis, blepharitis, or dacryocystitis, it ought to be cured or alleviated before the operation is undertaken. Very successful operations may be performed in the presence of chronic dacryocystitis, or granular ophthalmia, but it is in all respects wiser to reduce their activity to a minimum. THE CRYSTALLINE LENS. 325 Extraction of Cataract. Linear Extraction. — The extraction through a linear incision in the cornea is applicable only to soft or fluid cataracts, in Fig. 109. persons up to the age of twenty-five. The instruments required are : A spring lid elevator (Fig. 109), a fixation forceps, a wide Fig. 110. Pi Fig. 111. Fig. 112. VJ lance-shaped iridectomy knife (Fig. 110), a cystotome (Fig. Ill), and a Critchett's spoon (Fig. 112). The speculum having been applied, a fold of conjunctiva close to the margin of the cornea, and at the inner end of the hori- 326 DISEASES OF THE EYE. zontal meridian of the latter, is seized with the fixation forceps (Fig. 113), and the eye fixed by it throughout the operation The point of the knife is now entered into the cornea in its hori- zontal meridian, about 4 mm. from its outer margin, and passed into the anterior chamber. The blade of the knife is then laid Fig. 113. 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 humor commences to flow off" — the instrument is very slowly withdrawn, so that the aqueous humor may come Fig. 114. away gradually, without causing prolapse of the iris. In with- drawing 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. The knife being now put aside, the cystotome is passed into THE CRYSTALLINE LENS. 327 the anterior chamber (Fig. 114) as far as the opposite pupillary margin, care being taken, by keeping the sharp point of the instrument directed either up or down, not to entangle it in the wound or in the iris. The point is now turned directly on the anterior capsule, and, by withdrawing the cystotome toward the corneal incision, an opening in the capsule of the width of the pupil is produced. The cystotome is then removed from the anterior chamber with the same precautions as on its entrance. The edge of the spoon is then placed on the outer lip of the corneal incision, and the latter is made to gape somewhat, gentle pressure being at the same time applied to the inner aspect of the eye by the fixation forceps, and in this way the lens is evacuated. When the pupil has become quite black the operation is con- cluded. If pressure does 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 humor may be secreted. A renewal of the efibrts to clear the pupil will probably now be successful, or, if not, another pause may be made, and then fresh attempts employed until the pupil is quite clear. It is unwise to insert the spoon into the eye to withdraw the fragments, and if some of these should be left behind 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. Von Graefe, Waldau (Schuft), and Critchett endeavored, by increasing the size of the incision, placing it in the corneo-sclerotic margin, performing an iridectomy, and introducing a spoon for delivery of the cataract, to make the linear extraction applicable to senile cataracts. The successes derived from these modifica- tions were not, however, more satisfactory than those obtained from the old Flap Operation. But these experiments led von Graefe to the operation, a modification of which is now very generally employed. He called his operation The Modified Peripheral Linear Extraction. — The instruments 328 DISEASES OF THE EYE. Fig. 115. Fig. 116. Fig. 117. Fig. 118. THE CRYSTALLINE LENS. 329 required are: A wire lid-speculum, a fixation forceps with spring catch, a von Graefe's cataract knife (Fig. 115), a curved iris forceps, an iris scissors, or a de Wecker's forceps-scissors (Fig. 116), a bent cystotome, a hard-rubber spoon (Fig. 117), and a hard-rubber, tortoise-shell, or silver spatula (Fig. 118). Before proceeding to operate, the eye is nowadays thoroughly cocainized by the instillation of about three drops of a 2 per cent, solution of hydrochlorate of cocaine, at intervals of two or three minutes. Previously to the introduction of cocaine, general anaesthesia with ether or chloroform was commonly employed in England. I never used it. Antiseptic Measures, similar to those used for the Three Millimetre Flap Operation (vide infra), are to be carefully attended to. The Operation. — The speculum having been applied, the eye is steadied by seizing a fold of conjunctiva, with its sub-coujunctival tissue, close to the lower margin of the cornea, and in a prolonga- tion of the vertical meridian of the latter. The eye is now drawn gently downward, the patient assisting in the motion. The point of the Graefe's knife, its cutting edge being directed upward, is then entered into the corneo-sclerotic margin at a point {A in Fig. 119) about 1.5 m. from the outer and upper corneal margin, and 2 mm. below the level of the ^ 1.1 11 1 111-1 Fig. 119. tangent which would pass through the highest point of the corneal margin. The blade is held in a plane parallel to that of the iris, and is pushed on into the anterior chamber until its point reaches the point C, some 7 or 8 mm. of the blade being now^ in the anterior chamber. The handle of the knife is then lowered, so that the point of the blade is brought up to B, where it is made to pass out through the corneo-sclerotic margin, this counter-puncture corresponding in position, with reference to the corneal margin, to the point of entrance A. The edge of the knife is now turned slightly forward, and by one or two sawing motions the incision A B is completed in the corneo-sclerotic margin. The blade still lies under the conjunctiva, which is 330 DISEASES OF THE EYE. divided, the edge of the instrument being turned more forward, or even somewhat downward, as it is not desirable to have too large a conjunctival flap. The advantage of this incision lies in its peripheral position, which is almost in the plane of the crystalline lens, and conse- quently enables the cataract to be delivered without revolution on its axis. At a later period von Graefe altered the incision, so that, puncture and counterpuncture lying as described, the cen- tre of the incision passed through the apex of the clear cornea, instead of through the corneo-sclerotic margin. This, by making the incision more nearly a segment of a greater circle of a sphere, made it as linear as possible, and consequently, in his opinion, its margins adapted themselves more readily. The next step in the operation is an iridectomy, a portion of iris corresponding to the whole length of the wound, or nearly as much, being excised. This iridectomy is necessary or advisable chiefly because of the peripheral position of the wound, which would render prolapse of the iris very liable to occur, but it also facilitates the delivery of the lens and cortical masses. The sub- sequent stages — capsulotoray and delivery of the lens — are simi- lar in their details to those in the Three Millimetre Flap Opera- tion, to be presently described. It was found that the advantages of the position and form of the incision in this procedure were largely counterbalanced by the danger of prolapse of the vitreous, the difficulty of proper reposition of the angles of the coloboma, and the liability to cyclitis, all entailed by the peripheral incision, and, consequently, this incision has been abandoned by nearly all operators. Out of this method grew that one which is known as The Three Millimetre Flap Operation, first proposed by de Wecker. I shall describe the operation as I am in the habit of performing it ; and I may here say that, for success in the cataract opera- tion, it is necessary not only to select the method which seems the most rational, but also to devote the utmost attention to a series of minute details in its performance. Preparation of the Patient. — A gentle purgative is given the THE CRYSTALLINE LENS. 331 day before the operation, so that the bowels need not be disturbed for two days after the operation. In the case of hospital patients, the face is washed with hot water and soap shortly before the operation. Preparation of the Eye. — Half an hour before the operation, a drop of a 2 per cent, solution of sulphate of eserine (made with a 1 in 5000 solution of corrosive sublimate) is dropped into the eye, and this is repeated a quarter of an hour later. Just before the operation, at intervals of two minutes, three drops of a 2 per cent, solution (made with corrosive sublimate solution) of muriate of cocaine are dropped into the eye. Finally, the lids having been everted, the conjunctival sac is washed out with solution of corrosive sublimate, 1 in 10,000, 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 freely washed with the same solution. Preparation of the Instruments. — The instruments required are the same as those for the Modified Linear Extraction. Imme- diately before the operation they are sterilized by boiling ; out of the boiling water they are plunged for a moment into abso- lute alcohol, and laid in a bath of a 1 in 2300 solution of hydro- naphthol until required for use. During the Progress of the Operation small bits of lint, wet with the 1 in 10,000 sublimate lotion, are employed to wipe away coagula, cortical masses, etc., and are not employed a sec- ond 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 him 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 conjunc- tiva and subconjunctival tissue below the vertical meridian of the cornea, or a little to one side of this line (Fig. 120). The point of the knife is entered just in the margin of the clear cornea, at the outer extremity of a horizontal line which 332 DISEASES OF THE EYE. would pass 3 mm. below the summit of the cornea. This line is easily found by placing the knife, which is about 2 mm. broad, horizontally across the cornea, so that a margin of clear corneal tissue 1 m. broad «iay remain exposed between the knife and the summit of the cornea. The knife is then passed cautiously through the anterior chamber, and the counterpunc- ture made in the corneal margin at the inner extremity of the horizontal line described, and the incision finished in the corneal margin by a few slow to-and-fro motions of the knife. Owing to the action of the eserine the iris does not prolapse. The incision, between puncture and counterpuncture, lies in the clear cornea at its very margin, as represented by the dotted line in Fig. 120. This incision is no longer linear, but slightly curved. It is found, however, to adapt itself readily, and, being less peripheral than the true von Graefe incision, the objections to the latter are obviated. 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 to the centre of the incision, drawing it out, and with the forceps- scissors excising a very small central bit of iris. This is done, either by making two snips in the iris, one at either side of and close to the forceps, each of them reaching to the periphery of the iris, and then a third cut which joins these two at the base ; or, the forceps-scissors being approached from over the cornea, the coloboma may be formed with one snip of the instrument, and, if care be taken to keep the blades close to the forceps, a narrow, neat coloboma may thus be obtained. It is unneces- sary to excise' a large portion of iris, although in von Graefe's original operation a portion corresponding to the entire length of the wound used to be taken away. A small coloboma, say of 2 mm. to 3 mm. in width, as in Fig. 100, is sufficient to allow of an easy delivery of the lens by doing away with the resistance of the sphincter iridis, and its advantages over a wide iridectomy, THE CRYSTALLINE LENS. 333 Fig. 120. from an aesthetic point of view, are obvious. It is always, there- fore, my object 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 (see Fig. 120) by the instillation of one or two drops of solution of sulphate of eserine, as above recommended. The Third Stage of the operation is the Capsulotomy. The operator takes the fix- ation 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 remain- der of the operation. The surgeon, passing the cystotome into the anterior chamber, divides the anterior capsule of the lens by two incisions, each from the lower pupillary margin upward, one directed outward, the other inward, as far as the anterior sur- face of the lens can be seen, while finally a third incision is made along the upper periphery of the lens. An extensive opening in the capsule is of great importance, as otherwise difficulty in delivery of the lens may be experienced, and because a small opening renders the occurrence of secondary cataract more likely. In dividing 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 often drags 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. 334 DISEASES OF THE EYE. Capsule forceps have been invented for the purpose of taking away a large portion of the anterior capsule, but this does not altogether obviate the danger of capsule in the wound, nor does it do away with the likelihood of secondary cataract. I have no objection to the method, but it does not seem to have any advantages over that just described in cases where the capsule is not thickened. When the capsule is thickened, it is always desirable to tear away a central portion of it with forceps. Gayet, of Lyons,* and Knapp, of New York,f have proposed a method of opening the capsule termed peripheral division — i. e., they make only one opening in the capsule at the upper periphery of the lens with a very sharp " needle cystotome," which is passed along the whole length of the corneal section, a wide iridectomy having been made for this purpose. The chief advantages claimed for this method are: Safety from a tag of capsule in the wound, and safety from iritis caused by irritation from particles of lenticular substance left behind after delivery of the lens. On the other hand, it has the disadvantages of the wide iridectomy and of the secondary operation on the capsule, which is necessary in a large proportion of the cases. The Fourth Stage is the Delivery of the Cataract. The eye is drawn gently downward — the patient being called on to assist in this motion by looking toward his feet — the convex edge of the hard-rubber spoon is placed just below the lower edge of the cornea, and gentle pressure is exercised on this place, the pressure to be 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 in an upward direction, pushing the lens before it and out through the wound. As soon as the greatest diameter of the lens has passed the wound, the pressure of the spoon should at once be diminished, lest rupture of the zonula be caused. The fixation-forceps and * Gazette Hebdomadaire, 1875, No. 35. fAi'chives of Ophthalmology and Otology, Vol. vi, p. 545. THE CRYSTALLINE LENS. 335 speculum are now removed from the eye, and a cold compress with sublimate lotion is laid on the closed lids. 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 in what is called the " Toilette " of the Wound. The presence of cortical remains is recognized 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 inspec- tion of the cataract just removed showing that some portions of it are left behind. The use also .of the oblique illumination for the detection of cortical fragments is very advantageous. If any fragments be present, the cold antiseptic compress having lain on the eye for a few minutes to enable some aqueous humor to collect, the operator, facing the patient, raises the upper lid with the thumb of one hand, while, with the first and second fingers of the other laid on the lower lid, light rotatory motions are made with this lid over the cornea so as to collect the masses toward the pupil, and then a few rapid, light motions upward with the margin of the lid drive these masses toward, and out of, the wound. Care and delicacy of touch are required in order to perform this lid-manoeuvre successfully, without rupturing the hyaloid by undue pressure. Irrigation of the anterior chamber, or intracapsular injection, is a method which has been proposed by M'Keown and by Wiecherkiewicz, and practiced by them and some other sur- geons, for the removal of cortical masses. By its aid, too, M'Keown"^ operates on unripe cataracts. I have not adopted the procedure in my own operations, because, from the accounts given of the results, it does not seem to be free from danger to the eye, and because the ends proposed to be attained by it can be accomplished by other, and safer, means : the removal of cortical masses in cases of ripe cataract by the lid manoeuvre ; * Brit. Med. Jour?u, January 28, 1888. 336 DISEASES OF THE EYE. while unripe cataracts, so far as it is justifiable to deal with thera, are best dealt with by the raethod of artificial maturation proposed by Forster (p. 315). Irrigation of the anterior cham- ber, after delivery of the lens, with a 1 in 25,000 solution of bin- iodide of mercury, is used by Panas* from an antiseptic point of view; while de Wecker and others inject a solution of eserine to prevent prolapse of the iris. Both of these operators employ the method of extraction without iridectomy. With an iris-forceps the blood-clots which may adhere to the wound are now removed. I then invariably employ the following manoeuvre to prevent the possibility of any portion of capsule being incarcerated in the wound during healing. A bent iris-forceps is passed open between the lips of the wound, closed, and drawn gently out again. Frequently a tag of capsule will have been captured by the forceps and is snipped off with the scissors, or it may be that no capsule is caught. The forceps is then similarly inserted at an adjacent part of the wound, and in this manner the wound is searched from end to end for capsule. In about twenty-five per cent, of the cases a tag of capsule is found present. I regard this manoeuvre, which I am not aware that any other surgeon has previously recommended, as an important one, for I believe that it effectually removes the one serious drawback to the valu- able operation under consideration. Finally, the coloboma has to be seen to. The peripheral portions of the iris, corresponding to the ends of the wound, are apt to have become prolapsed in the course of the operation, and to have displaced the angles of the coloboma upward. 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 mouths becoming drawn up toward 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, * Panas's Solution = Biniodide of Mercury gr. | dissolved in Absolute Alcohol 5 vj. Add Distilled Water 1 quart. Shake and filter. THE CRYSTALLINE LENS. 337 and to gently stroke down each pillar of the coloboma as far as it can be brought. The instillation of eserine before the com- mencement of the operation will cause the sphincter iridis to assist in producing the desired result. 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. Having secured the required advantage from the effect of the eserine, a drop of atropine is put into the eye before applying the bandage, in order to do away with the myosis, which might give a tendency to iritis. The dressing is now applied. A piece of lint, sufficiently large to extend i inch beyond the orbital margin in every direction, is soaked in a solution of corrosive sublimate (1 in 5000) and laid on the closed eyelids. Pledgets of absorbent cotton wool, soaked in the same solution, are laid on this, the hollows at the inner canthus, etc., being carefully filled up; so that, when the bandage is put on, it may exert equal pressure on every part of the eye. Over all comes a layer of oiled silk protective. I apply three turns of a narrow flannel roller over the dressing and round the head, in the manner which was customary in von Graefe's clinique; but various other, and doubtless equally good, forms of bandage are in use. The pressure of the bandage need only be suflScient to maintain the dressing firmly in its place. It is usual to keep the other eye closed by a light bandage. I am opposed to the after-treatment of cataract operations without bandage, as advocated by some surgeons. It is by no means a new method, and I do not doubt that many cases re- cover under it. I do not believe, however, that, in a long series of cases, the same percentage of recoveries can be obtained by it as with the bandage. Accidents liable to occur during the Operation. — The wound may be made too small. The delivery of the lens, consequently, may be so difficult that the margins of the wound are contused, and then suppuration may be promoted. The zonula, too, may 29 338 DISEASES OF THE EYE. be ruptured by the excessive pressure from efforts to force the lens out, 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 pur- pose. Where the presence of an unusually large hard cataract is diagnosed, it is important to make the incision larger ab initio, by placing puncture and counterpuncture nearer to the horizontal meridian of the cornea than above directed. Hemorrhage into the Anterior Chamber may take place. It may be from the iris, from the corneo-sclerotic margin, or from the conjunctiva. 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. Still, when this cannot be completely got rid of, the capsulotomy may be performed with the exercise of greater care. Cocaine, by its power to contract the blood vessels, has rendered this hemorrhage a less common complication than it used to be. Prolapse of the Vitreous Humor. This may be due to a too peripheral position of the wound, support being thus taken away from the zonula, and the danger of its occurrence was a disad- vantage of the completely corneo-sclerotic wound practiced at one time by von Graefe. The Three Millimetre Flap Operation is less liable to be attended with loss of vitreous. This accident may also be caused by undue pressure made on the eyeball by the speculum, fixation-forceps, or spoon, or by the under-lid dur- ing the lid-manoeuvre. It may be due to defective zonula with fluid vitreous humor. If the vitreous prolapses prior to delivery of the lens, the latter falls back into the eye, and can only be delivered by at once drawing it out with a Critchett's, Taylor's, or other suitable vectis ; and this may be regarded as one of the most serious accidents which can occur in the course of the opera- tion. Loss of vitreous after delivery of the lens is less serious; indeed, a considerable portion of the vitreous may then be lost THE CRYSTALLINE LENS. 339 without ill-result to the eye. Still, it increases the traumatism and renders inflammatory reaction more liable to occur. Opac- ities in the posterior chamber of the eye are frequently an ultimate result of loss of vitreous ; but a much more serious con- sequence is sometimes seen in detachment of the retina. Normal After-Progress. — Soon after the completion of a normal operation, the effect of the cocaine having passed off, some smart- ing 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 band- age. The first dressing is made in forty-eight hours, in a man- ner similar to that immediately after the operation, a drop of atropine being instilled, as also at each successive dressing; and the corrosive sublimate solution is used for freely washing the margins of the eyelids, some of it being allowed to trickle into the conjunctival sac. At this first dressing it is well to abstain from a minute or lengthened examination of the eye; but, if the lid be gently raised, the wound will be found closed, the cornea clear, the anterior chamber completely restored, and the pupil semi-dilated and black. The subsequent 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 permanently and dark glasses worn in its stead. In the course of a few days more the patient, having been gradually used 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 vas- cular 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 con- tinue longer than four or five hours, and it is then well to quiet it by a hypodermic injection of morphia in the corresponding temple. Should severe pain come on some hours later, it is apt 340 DISEASES OF THE EYE. to be due to an accumulation of tears under the eyelids, and it iranaediately subsides on the bandage being removed and exit given to the tears by slightly opening the eye. Antiseptic pre- cautions are to be observed while this is being done. 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 quite satis- factory ; but this need occasion no alarm, as the anterior cham- ber is sometimes not restored for a week or more. Striped Keratitis. At this dressing also it may 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 neighborhood of the wound. This opacity is the result of injury to the endothelium of the posterior surface of the cornea during the operation by instru- ments, or by the chemical action of the antiseptic lotion. Leber has shown that the entrance of even the aqueous humor, through a loss of substance in the endothelium, is sufficient to cause the fibres of the true cornea to swell and become opaque, just as the crystalline lens is acted on if its capsule be opened. The endo- thelium of the posterior surface of the cornea in fact it is, which protects the latter from being infiltrated by the aqueous humor. This 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. But now and then cases do occur in which the process is very intense, and where a permanent white opacity remains in the cornea over the pupillary area, with con- sequent serious deterioration of vision. These severe cases are most apt to be caused by the introduction of the antiseptic solu- tion into the anterior chamber ; for the chemical action of the antiseptic on the corneal tissues is more damaging, and therefore the opacity it produces more permanent, than is the action of the aqueous humor. Sublimate lotion is the antiseptic which has been most often to blame, probably because it is the antiseptic in most general use. Even a sublimate lotion of 1 in 10,000, if introduced freely into the anterior chamber, may cause the mild THE CRYSTALLINE LENS. 341 form of striped keratitis. Yet, with the 1 in 5000 solution which I have until recently employed, I never had the severe form, and rarely the mild form ; but then I never deliberately introduced the solution into the anterior chamber. I have had only one case of the severe form, and in it, by mistake, a sublimate lotion of 1 in 2500 was used for irrigation of the surface of the eye. No doubt, in irrigation of the surface of the eye, some of the lotion used is liable to make its way into the anterior chamber. Boric acid solutions ( 3 per cent.) do not injure the endothelium, but I have little faith in their antiseptic properties. Suppuration of the Wound. This is a danger which is very much rarer than it was prior to the introduction of antiseptics into surgery ; indeed, it is almost banished from the cataract operation. When it occurs, it usually does so between the twelfth and thirty-sixth hour after the operation, rarely earlier or later, and is a very serious event ; for, in the vast majority of cases, do the surgeon what he may, it leads to loss of the eye. Its onset is made known by severe pain of a continuous aching kind in and about the eye, and is thus easily distinguished from the slight, short, stabbing pain, with long intermissions, which some patients complain of and which has no evil import. On removing the bandage the eye will be found full of tears and the wound covered with a layer of muco-pus, which can be re- moved with the forceps in one mass, while the aqueous humor and cornea may already present some opacity. In some hours more the corneal opacity increases considerably, the iris becomes distinctly inflamed, and the pupil filled with a mass of inflam- matory exudation. 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 toward the wound, so that an ap- pearance as in Fig. 121 is presented ; or the inflam- mation may strike into the ciliary body and choroid, and produce purulent panophthalmitis, with total destruction of the eye. To combat Suppuration, the best method is the immediate cau- terization of the corneal wound in its whole extent with the 342 DISEASES OF THE EYE. galvauo-cautery. Also, the wound may be opened up from end to end with a spatula, the aqueous humor evacuated, and the anterior chamber washed out with injections of corrosive subli- mate solution, 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. Iritis. Apart from the iritis which occurs in connection with suppuration of the wound, this complication is most usually due to irritation from masses of cortical lens-substance left behind. It may also be due to dragging from a tag of the iris being left in the wound, or to too early exposure to the daylight. Corti- cal masses do not usually give rise to it for some days after the operation. It is ushered in with the usual symptoms of pain, and is generally of the plastic variety. If it extend to the ciliary body, sympathetic ophthalmitis may result. Its treatment con- sists in strict confinement to a dark room, atropine, warm foment- ations, leeching, and, internally, quinine. In these cases vision is liable to be damaged by pupillary exudation, which remains as a permanent obstruction to vision. Cystoid Cicatrix. After convalescence, all the foregoing dan- gers having been escaped, the cicatrix in the corneal margin sometimes bulges and becomes semi-transparent, presenting the appearance of a vesicle, and may attain a large size. The extremities of the late incision are the most common positions for this condition, but it may occupy the entire length of the cica- trix. It does not generally come on 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 probably by a bit of capsule, which has similarly healed in the wound. Irregularity in curvature of the cornea and consequent irregular astigmatism are the least of its evil consequences. If the condi- tion be caused by incarceration of iris, the pupil will be gradu- ally drawn close to the upper corneo-sclerotic margin ; while, if it be caused by a portion of capsule, irido-cyclitis may be pro- duced. Whether the iris or the capsule be the cause, these eyes are always exposed to the danger of a sudden onset of purulent THE CRYSTALLINE LENS. 348 irido-choroiditis (see p. 193). All this demonstrates the immense importance of attention to those details of the operation which are calculated to obviate incarceration of iris or of capsule in the cicatrix. Cataract Extraction without Iridectomy.* — This method is older than the Linear, von Graefe's, or the Three Millimetre Flap Operation, and used to be known as The Flap Operation. It has been revived within the last two years by some most dis- tinguished ophthalmic surgeons, chiefly in Paris, but also in Ger- many and America, and even in England. It differs from the Three Millimetre Flap Operation in that the incision occupies a greater extent (about one-third) of the circumference of the cornea, and that no iridectomy is made. Formerly the knife used w^as triangular in shape (Beer's knife), but von Graefe's cataract knife is the instrument now employed. The round pupil, and consequent somewhat prettier appearance of the eye. is the one advantage which can be claimed for this procedure over the Three Millimetre Flap Operation, as it has been above described, for the vision with a circular pupil is not better than where a small iridectomy has been done. As a set-off against the circular pupil, the extraction without iridectomy exposes the eye to the serious danger of prolapse of the iris into the wound. These operators make it a rule to perform an iridectomy in all cases where they cannot satisfactorily repose the iris after delivery of the lens, but even where they can repose it well, they are not, they state, secure against the occurrence of a prolapse within the first two or three days after the operation ; nor do they find that eserine, or any other means, provides the desired safeguard. It is admitted that prolapse of the iris takes place after a number of these operations, and that there is no means of foretelling in what eyes it will occur. The prolapsed portion of iris heals in the wound, which then, in a few weeks, becomes ■^ Known now very generally as The Simple Method, while the opera- tion combined with an iridectomy is now commonly termed The Combined Method. 344 DISEASES OF THE EYE. 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 dis- advantage of this operation is, that removal of cortical remains cannot be so effectually performed as where acoloboma has been made. Therefore, while admitting the charm of a circular pupil, I am of opinion that the question is not whether the appearance of some of the eyes operated on is pleasing to us, and to others who inspect them, but, rather, what advantage the greatest number of persons operated on derive from the operation. With sentimental talk about " mutilation " of the iris I cannot pretend to sympa- thize. If the advocates of the method under discussion should find a means of insuring the eye against prolapse of the iris, the operation will be placed upon a different footing, but until then the procedure cannot, I think, be recommended. It is easy to understand why, in the simple extraction, pro- lapse of the iris with subsequent incarceration is so liable to occur, even some days after the operation, and why it is so diffi- cult to devise a sure means for preventing the accident; as, also, how it is that even a very narrow coloboma is sufficient to protect the eye from this disaster. And yet I am inclined to think that among those oculists who have reverted to the simple method there are some who do not realize the modus operandi in either case. Within a few hours after the operation the wound in the corneal margin most commonly closes, the aqueous humor 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 little — a cough, a sneeze, a motion of the head, the necessary efforts in the use of a urninal or bed-pan, no matter how careful the nursing — to rupture the newly formed union, and, as a matter of fact, this often does take place. The aqueous humor then flows away through the wound with a sudden gush, and, where THE CRYSTALLINE LENS. 345 the simple extraction has been employed, carries with it the iris. Doubtless, in this event, it is that portion of the aqueous humor which is situated behind the iris, which is chiefly concerned in the iris-prolapse; the aqueous humor in the anterior part of the anterior chamber probably flows off" without influencing the position of the iris. The advocates of the simple operation en- deavor to prevent secondary iris-prolapse by a spastic contraction of the pupil, produced by eserine, which is instilled at the con- clusion of the operation, and again, by some operators, a few hours afterward. In most instances the desired end is by this means efl^ected. But there is a considerable percentage of the cases in which the contraction of the sphincter iridis is overcome by the pressure of the aqueous humor from behind, and iris- prolapse takes place. How, then, does the formation of a coloboraa prevent prolapse of the iris, when the wound bursts, as I have described ? Not because the portion of iris which is liable to prolapse has been taken away. That would mean nothing less than the whole of that part of the iris which corresponds to the length of the open- ing in the corneal margin. But the coloboma averts secondary iris-prolapse, because it provides a gateway, a sluice, for the aqueous humor contained in the posterior part of the anterior chamber to escape directly through the wound, without carrying with it the iris in its rush ; and it is evident that the narrowest coloboma which can be formed will be amply sufficient for the purpose. To my mind a narrow iridectomy here is no "mutila- tion of the iris," but rather a measure which rests upon a sound scientific basis, and which is calculated to ensure the safety of the eye in an important particular. As to disfigurement of the eye, there is practically none when the coloboma is so narrow and is situated in the upper part of the iris. The pupil, too, is movable, almost, if not quite as much so, I venture to say, as in most cases of simple extraction. For it is entirely a mistake to suppose that a narrow coloboma renders the pupil immovable. Where there are no adhesions between the pupillary margin and the capsule, as frequently happens, the 346 DISEASES OF THE EYE. reaction to light is active, a drop of atropine will dilate the pupil widely, and a drop of eserine will contract it. Mental Derangements after Cataract Extractions. — After cata- ract extractions, during the period of confinement to bed, passing mental disturbances are 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 the exclusion of light, following on a period of some anxiety and excitement. A few doses of sul- phonal and permission to sit up — at least in bed — with the admission of more daylight, will be the best measures to adopt in such a case; and speedy restoration of mental equilibrium may be looked for with confidence. 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 per formed. This is contrary to what one would have expected, in view of the diminished contents of the globe, by reason of absence of the lens, and especially in those cases where an iri- dectomy 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 many years. Treacher Collins' * and Natanson's f microscopic investigations show that in these cases either the iris, the capsule, or the hyaloid, has become en- tangled in the wound, and it seems that this leads in some cases to closure of the filtration angle in its entire circumference; but, obviously, further information is required on this rather obscure (question. A wide iridectomy, or a sclerotomy, should be made as soon as possible after the high tension shows itself, and by this means many of these eyes may be saved. Discission or Dilaceration means the tearing of the anterior * Trans. Ophth. Sac, vol. x, p. 108. t "Ueber Glaucom in Aphakischen Augen." Dorpat, 1889. THE CRYSTALLINE LENS. 347 capsule of the lens with a needle, so as to give the aqueous humor access to the lenticular fibres, which causes them to swell, and gradually to become soft, and then to be absorbed. The larger the capsular opening, the more freely is the ^^' aqueous brought in contact with the lens, and the more rapid is its swelling. The rapidity of the swell- ing and absorption depend, also, on the consistence of the lens. The softer it is, the more rapid is the pro- cess, the completion of which may require from a few weeks to many months. It is wise to make the first discission of moderate dimensions, in order to test the irritability of the eye, especially in adults. The instruments required are a spring speculum, a fixation forceps, and a Bowman's stop-needle (Fig. 122). The shoulder on the latter instrument prevents its advance too far into the eye. The pupil is to be dilated with atropine. The eye having been cocainized, the speculum applied, and the eye fixed close to the inner margin of the cornea, the needle is passed perpendicularly through the cornea in its lower and outer quadrant, at a point correspond- ing to the margin of the dilated pupil. It is then ad- vanced upward to the upper margin of the pupil (Fig. 123), where it is passed into the capsule, but not deeply into the lens, and a vertical incision is effected by with- drawing the instrument slightly. If an extensive open- ing in the capsule be wished for, a horizontal incision can be added to the vertical by a corresponding motion of the needle. During these manoeuvres, the cornea, at the point of puncture, must form the fulcrum for the motions of the instrument. The instrument is then withdrawn and some aqueous humor escapes through the opening. Atropine is instilled and the bandage applied. The patient is kept in bed, in a darkened '\]J room, for a day, and then the bandage may be dispensed with and dark spectacles worn. The iris is to be kept well under 348 DISEASES OF THE EYE. the influence of atropine until tlie absorption of the lens is com- pleted. 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 become closed up. This method is applicable to all complete cataracts up to the twenty-fifth year of age, and to those lamellar cataracts in which the opacity approaches so close to the periphery of the lens that nothing can be gained by an iridectomy. After the above age the increasing hardness of the nucleus and the in- creasing irritability of the iris render the method unsuitable. Discission is a safe pro- FiG. 123. cedure when used with the above indications and pre- cautions. The danger chiefly to be feared is iritis, from pressure on the iris of the swelling lens masses. When this occurs, or is threatened, removal of the cataract by a linear inci- sion in the cornea should be at once performed. A safeguard against iritis may be had in a preliminary iridectomy (von Graefe), and it is, perhaps, well to do this in all cases over fifteen years of age, the discission following some weeks afterward. Another danger consists in glaucomatous increase of tension (secondary glaucoma), which may come on without any subjec- tive symptoms, while the absorption of the lens runs its proper course. It may happen, in this way, that when absorption of the cataract is completed, the eye will be found blind from glaucoma. Frequent testings of the tension of the eye during the cure are, therefore, a most important precaution. Should the tension rise, removal of the lens through a linear incision in the cornea is at once indicated ; or, the suction operation may be employed. THE CRYSTALLINE LENS. 349 Suction Operation of Cataract. — This method can only be used for semi-fluid or soft cataracts. The pupil having been well dilated with atropine, and the eye cocainized, a free opening is made in the capsule of the lens with a discission needle. A linear incision is then made in the cornea about half way between its centre and its margin, and the point of a Bowman's or a Teale's syringe introduced through it, and through the opening in the capsule, into the substance of the lens. Gentle suction is then applied, and the lens substance drawn into the syringe. The syringe should not be passed be- hind the iris. If it be thought that the cataract is not suffi- ciently soft, it is desirable to allow some time (a fortnight or so) to elapse between the discission and the suction, in order that the lens substance may undergo disintegration by the action of the aqueous humor. Secondary Cataract and its Operation — Capsulotomy.— The term "secondary cataract," as here used (compare p. 319), usu- ally means a closure of the opening in the anterior capsule left after the removal of a cataractous lens, with sometimes a thick- ening of the capsule, by which 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. The term is also used with reference to those cases in which no central opening has been made in the capsule (peri- pheral capsulotomy), and where the latter causes imperfect vis- ion. It is also used in those cases where, after cataract extrac- tion, an exudation in the pupil, consequent upon iritis, has occurred. And finally, it is applied to the cases which Fig. 121 represents, in which, after suppuration of the wound with irido- cyclitis, the iris is dragged upward, and the pupil consequently obliterated. The most simple form of secondary cataract occurs as a very fine cobweb-like membrane, extending over the whole area of the pupil, which can often only be discovered by careful examina- tion with oblique illumination. It may not appear until some 350 DISEASES OF THE EYE. months after the extraction, and then causes the patient to com- plain of diminished acuteness of vision. It is a simple matter to make a rent in this delicate membrane with a discission needle. Where there are thick opacities in the capsule or inflammatory exudation into the pupil, with, probably, adhesions of the iris to the pupillary membrane, extraction of the latter has been pro- posed and practiced, but is associated with so much danger, from the unavoidable dragging on the ciliary body and iris, that the proceeding is not often employed. Fig. 124. Sir W. Bowman's Method with two needles is here much prefer- able. In it the point of a discission needle is passed through the inner quadrant of the cornea and into the centre of the opacity (Fig. 124), and then, with the other hand, a second needle is passed through the outer quadrant of the cornea and into the membrane, close beside the first needle. The points of the needles are now separated from each other by approximation of their handles, and in this way a hole is made in the membrane. A very small opening in the capsule, if quite clear, is sufficient to establish good vision. THE CRYSTALLINE LENS. 351 Dr. Xoyess Method.'^ — A Graefe's cataract-knife is entered in the horizontal meridian of the cornea at its temporal margin, and a counterpuncture made in the same meridian at the inner corneal margin. The point of the knife is now withdrawn into the anterior chamber, and made to puncture the secondary cataract, and is then removed from the eye. Two blunt-pointed hooks are then entered into the anterior chamber, one through each corneal puncture, and the point of each passed through the opening in the membrane made with the knife. By traction on the hooks this opening is enlarged without any dragging on the iris or ciliary body. Tridotomy. — For the cases, as in Fig. 121, where the iris forms a complete and tightly stretched curtain across the pupil, iridec- tomy is the operation which readily suggests itself. In very few cases, however, does it give a satisfactory result, owing to the inflammatory products which lie behind the iris and which close up any artificial pupil by their proliferation, which is set going by the dragging of the iris with the forceps. Repeated iridec- tomies may finally produce a clear pupil, but iridotomy, in which there is no dragging of the iris, is a better operation in these cases. There are several modes of performing iridotomy, that of de Wecker being the best. 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 -1: mm. behind it. By now 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. Dislocation of the Crystalline Lens. — This may be congenital, and due to arrested development of the zonula of Zinn ; or it may be the result of disease, such, for example, as anterior Diseases of the Eye"' (London, 1882), p. 251. 352 DISEASES OF THE EYE. sclero-choroiditis ; or it may be caused by a blow, or other trauma. The dislocation may be partial or complete. In the former case it is often so slight as to be discoverable only when the pupil is widely dilated, the margin of the lens becoming then visible as a black line in some one direction, by aid of the ophthalmoscope mirror. Or, the displacement may be so great as to bring the margin of the lens across the centre of the un- dilated pupil, in which case one part of the eye will be highly hypermetropic, while in another part it will be myopic. Com- plete dislocation may take place into the anterior chamber, into the vitreous humor, and even under the conjunctiva, if the sclerotic has been ruptured. 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 by the lens. In complete dislocation the symptoms are those of aphakia, i. e., extreme hypermetropia and want of power of accommoda- tion. Treatment. — In partial dislocation it is rarely that any treat- ment can be of service. The prescribing of spectacles suited, so far as 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. Dislocation into the vitreous humor is generally unattended by irritation ; but, when the latter does arise, re- moval of the lens by aid of a spoon, through a peripheral corneal incision, has to be attempted. Lenticonus is a very rare congenital anomaly of the lens, in which the anterior surface, or, still more rarely, the posterior surface, is cone-shaped. Aphakia («, jyriv.; ^a/.o:;, a lentil, lens), or Absence of the Crystalline Lens. — The condition of the emmetropic eye after the removal of a cataract is one of high hypermetropia, and the power of accommodation is wanting. Consequently, in order THE CRYSTALLINE LENS. 353 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 stronger lenses must be prescribed for shorter dis- tances. The degree of vision obtained varies considerably in different cases ; frequently Y = f is obtained, but Y = ^ may be re- garded as a satisfactory result, and even lower degrees, which enable the patients to find their way about with comfort, are classed as successful operations. The vision often improves for some months after the operation, patients who at first had only jig or so advancing up to f or f. For reading, writing, etc., at about 25 cm., a still higher convex glass must be provided. If the correcting lens for distant vision be -]- 10 D, its power, for vision at 25 cm., must be increased by the lens which would rep- resent the amplitude of accommodation from infinite distance up to 25 cm. This lens is 4 D (because ^J'- = 4, therefore -|- 14 D is the lens required. With these two lenses most 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 further from, the eye ; but, if necessary, a lens can be pre- scribed for distinct vision at any desired distance. In the case of hospital patients, one is often obliged to select the -j- glasses in 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 ofl^, and this varies in different cases. Until then, also, dark protection spectacles should be worn. In a large number of cases, after cataract operations, the best vision is not obtained until existing astigmatism is corrected, and in ascertaining its degree the astigmometer is of great service. High degrees of astigmatism are often present after cataract operations, in eyes which previously were free from it. This may be due to astigmatism of the cornea having been formerly compensated by an opposite form of astigmatism of the lens ; or, it may be the result of cicatrical contraction of the corneal 30 354 DISEASES OF THE EYE. wound. The astigmatism here is usually " against the rule " (see p. 39), and greater for some weeks after the operation than later on, and therefore it is well not to prescribe cylindrical glasses for at least two months subsequent to the operation. (For an account of Erythropsia after cataract extraction see Chap. XYII.) CHAPTER XIV. DISEASES OF THE VITREOUS HUMOR. Purulent Inflammation of the Vitreous Humor (to which, unfortunately, the name pseudo-glioma is sometimes applied) 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 choroid (p. 253). . Ophthalmoscojncally, a purulent deposit in the vitreous humor gives a yellowish reflection. It is to be distinguished from a somewhat similar appearance in glioma of the retina by the history, by its early complication with more or less severe iritis, by the very frequent retraction of the periphery of the iris, with bulging forward of its pupillary part, and by the diminished tension of the eye, while a lobulated appearance is not so usual in it as in glioma. Again, in glioma the vitreous humor remains clear, while in this disease it is hazy. The condition, if at first confined to the vitreous humor, soon extends to the surrounding tissues, and usually leads to panophthalmitis and complete destruction of the eye. Inflammatory Aff'ections of the Vitreous Humor, other than the purulent form, are, for the most part, the consequence of diseases of the choroid, ciliary body, or retina, and display themselves as opacities of various kinds. These either are cells derived from the primarily diseased tissue, or they are secondary changes (connective tissue development), the result of this cellular invasion. The chief Varieties of Vitreous Humor Opacities are: 1. The Dust-like Opacity so characteristic of syphilitic disease of the retina and choroid. It may occupy the entire vitreous humor, but is frequently confined to the region of the ciliary body, or to that of the posterior layers of the vitreous humor 355 356 DISEASES OF THE EYE. 2. Flakes and Threads. These occur with chronic affections of the choroid or ciliary body, and may be the result also of hemorrhages into the vitreous humor. They invade every portion of the humor. 3. Membranous Opacities, which are rare, and are probably the result either of extensive hemorrhagic extravasations or of choroidal exudations. Hemorrhages into the vitreous humor are not uncommon, and are the result of certain diseases of the retina and choroid, which are accompanied by hemorrhages in those membranes. They are also caused by blows on the eye which rupture the choroidal or retinal vessels. Most of the alterations occurring in the vitreous humor are attended with, or give rise to, fluidity of it. The Diagnosis of opacities in the vitreous humor is made with the ophthalmoscope mirror and a not very bright light, or with the plane mirror. If a very bright light and 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. Another and very fine method for the detection of delicate opacities in the vitreous, is by placing a high -f- lens, say -\- 10 D, behind the ophthalmoscope mirror, and then going close to the eye, as in the examination of the upright image. Minute opacities will then be seen as black dots floating in the vitreous humor. The ophthalmoscope does not always detect changes in the choroid or retina when there are opacities in the vitreous; and, in many such cases, we are led to the belief that the diseased changes in the choroid 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. Vision is affected by opacities in the vitreous humor in propor- tion to their density, and to the extent to which the vitreous humor is occupied by them. The patients often observe them as THE VITREOUS HUMOR. 357 floating positive scotomata in their field of vision. These *' en- toptic appearances " are caused by the shadows of the opacities thrown on the retina. The Prognosis depends on the cause of the opacities. Small hemorrhagic extravasations in young people are readily absorbed. The dust-like opacity of specific retinitis is also favorable for absorption, while extensive hemorrhages in older people, and the " flake and thread "opacities, frequently remain as permanent obstructions. Moreover, by shrinking, many of the more organ- ized opacities give rise to detachment of the retina from the choroid, and consequent blindness. Treatment consists, above all, in that for the exciting cause. Besides this, Heurteloup's artificial leech, or dry cupping on the temple, is most useful ; and in many cases, soon after the applica- tion, a marked clearing up of the vitreous is apparent. Pilo- carpine hypodermically is worthy of trial. In one case von Graefe operated on membranous opacities by tearing them with a needle, and with a successful result. Mouches Volantes, Muscae Volitantes, and Myodesopsia QiuTa^ afly; oiptq, seeing) , 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 ophthal- moscope detect opacities in the vitreous humor, or any other intraocular disease. These motes are most apparent when a bright surface, such as a white wall or field of a microscope, is looked at. Mouches volantes have no clinical importance. Those annoyed with them should be strongly recommended 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 tissue in the vitreous humor. Fluidity of the Vitreous Humor, or Synchysis (tuv, together ; yjio^ to pour), is not rare. It can only be diagnosed with certainty when the humor contains floating opacities. Low tension of the eyeball does not always indicate fluidity of the vitreous, although soft eyeballs nearly always contain fluid vitreous humor. Trem- bling of the iris is also no sign of fluid vitreous, but merely 358 DISEASES OF THE EYE. 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 choroiditis and staphyloma of the choroid and sclerotic, and it also occurs as a senile change. Synchysis Scintillans is a fluid condition of the vitreous humor, with cholesterine and tyrosine crystals held in suspension in it. The ophthalmoscopic appearances are very beautiful, resembling a shower of golden rain. A satisfactory explanation for the occurrence of these crystals in this position has not yet been given. They usually occur in old people, and seldom cause any marked deterioration of vision. Fluidity of the vitreous humor is not, per se, a condition of serious import, unless the eye come to be the subject of an operation involving an incision in the corneo-sclerotic coat, when it renders prolapse of the vitreous more liable to take place. Foreign Bodies in the Vitreous Humor. — One of the most common accidents 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 then lodge in the vitreous humor. In cases where the ophthalmoscope fails us, owing to extrava- sation of blood, etc., it is sometimes not easy to say whether the foreign body be in the eye, or whether it may merely have punc- tured the sclerotic and fallen to the ground. If it be known to have been a small foreign body, which has flown against the eye with force, the probabilities are that it is lodged in the eye. But if the case be brought immediately, or soon after the accident, and there be no intraocular hemorrhage to obscure our view, the foreign body may frequently be detected with the ophthalmoscope in the vitreous humor as a dark or glittering body, according to its nature. And focal illumination with dilated pupil will often help us to discover a foreign body situ- ated in the anterior part of the vitreous humor. Or if it cannot be seen, an opaque streak through the vitreous humor, one end THE VITREOUS HUMOR. 359 of which corresponds with the sclerotic wound, may indicate the track taken by a foreign body. In case the foreign body has perforated the cornea and reached the vitreous humor 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. It is rarely that a foreign body, whether it remain free, or, as sometimes happens, become encapsuled, is tolerated permanently in any part of the interior of the eye, and the event should never be calculated on in the treatment of such a case. As a rule, foreign bodies in the vitreous, as elsewhere within the eye, soon produce violent inflammatory reaction. This occurs either by reason of infective micro-organisms being intro- duced into the eye with the foreign body, or it may be caused by the oxidization of the foreign body, when, as is most common, it is of iron or copper. The form of inflammation may be either a plastic or purulent uveitis, in the latter case with purulent infil- tration of the vitreous humor and hypopyon. An eye which contains a foreign body that is not or cannot be at once removed, may be regarded as lost ; and such an eye becomes, moreover, one of the surest sources of sympathetic ophthalmitis. It is, consequently, of the utmost importance to remove every foreign body from the interior of the eye if possible, and with the least delay ; or, if not, carefully to watch the eye, and at any sign of inflammatory reaction to remove the eyeball. Indeed, in view of the fact that this inflammatory reaction almost invariably comes on sooner or later, I should be inclined to remove most of these eyes at once, when the foreign body cannot be extracted. Removal of the Foreign Body is often an extremely difficult and disappointing undertaking, but it should always be at- tempted when, being neither steel nor iron, it is visible within the eye, so that its position can be determined with the ophthal- moscope or by focal illumination. The introduction of the magnet for the removal of fragments of the two metals named 360 DISEASES OF THE EYE. has made it unnecessary that they should in every case be visible, although here too the chances of success are much enhanced if the foreign body can be accurately localized. In all these operations it is necessary that the patient should be deeply under the influence of an anaesthetic, in order that as little vitreous huDQor as possible may be lost. And again, strict antiseptic measures must be observed, lest by our operation the very form of mischief be produced which it is our desire to avert. There are several methods of proceeding. Atoms of glass, copper, stone, etc., 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 clearly corresponding to the actual position of the latter in the eye. This incision should lie between two recti muscles, should have an antero-posterior direction, 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 should only be tried when the foreign body is situated in the periphery of the vitreous, and toward the equator of the eye, where the opening for its exit can be made in its immediate neighborhood ; but the proceeding is often attended with disappointment, much vitreous being lost, while the foreign body remains in the eye. Or, a forceps is passed in through the opening, and while the foreign body is kept in view with the ophthalmoscope, it is seized and drawn out. This plan is also unsatisfactory, as, loss of vitreous occurring, the cornea becomes flaccid, and the view of the foreign body is soon obscured. Again, some surgeons prefer to make their opening not close to the foreign body, but exactly at the opposite side of the eye- ball, by which means they can often reach the foreign body with greater ease, and with less injury to the tissues. The magnet, thanks to M'Keown, of Belfast,* has of late * Brit. Med. Journal, 1874, vol. i, p. 800, and elsewhere. THE VITREOUS HUMOR. 361 years come into use for the removal of fragments of steel and iron from the interior of the eye, and especially from the vitreous humor. Electro-magnets are those now employed for this purpose, the instruments of Hirschberg"^ and of Simeon Snellt being the most suitable. Fig. 125 represents Mr. Snell's instrument in two-thirds its actual size. It is a core of soft iron, around which is placed a coil of insulated copper wire, the whole enclosed in an ebonite case. To one end of the instru- ment are attached the screws to receive the battery connections. At the other extremity the core projects just beyond the ebonite jacket, and is tapped, and into it screws the needle. Xeedles of various kinds or shapes can be adjusted to the magnet according Fig. 125. to the case to be dealt with. The battery used is a quart bichromate element. A needle being passed through the scle- rotic opening, is advanced toward the foreign body, when the latter adheres to it, and is drawn toward the wound. Much care is required in drawing it through the opening, lest it be rubbed off the needle 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. The magnet may also be used for determining the presence of a fragment of steel or iron in the vitreous, if, on bringing it close to the eye, motions are imparted to the fragment. * Centralblatt fiir prak. Augenheilkunde, 1879, p. 380. t The Electro-magnet, etc. (London, 1883). 31 362 DISEASES OF THE EYE. T. R. Pooley* made some very elegant experiments to ascertain the presence of a piece of steel in the eye, upon the principle that if a fixed magnet attracts a movable piece of steel, a fixed piece of steel will attract a movable magnet. He magnetized a sewing-needle, and suspended it by a fibre of silk attached to its centre, and on bringing it near an eye which contained an atom of steel the needle dipped toward the foreign body. Or, if he magnetized the foreign body by passing a galvanic current through the eye, the motion of the suspended magnet was even more decided. Cysticercus in the Vitreous Humor is not of rare occurrence in some parts of Germany, but there have been only one or two such cases observed in the British Isles. The original seat of the entozoon is usually beneath the retina (see Chap. XV), through which it breaks to reach the vitreous humor, but it also sometimes makes its first appearance in the vitreous. It is recognized by its peculiar, somewhat dumbbell shape, its iridescence, and its peristalic motions. The vitreous humor often becomes full of peculiar 'membranous opacities. Treatment. — Removal by operation. The prospects for the eye are very much worse than in the case of a subretinal cysticercus. Persistent Hyaloid Artery. — In intra-uterine life the hya- loid 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 stretch the whole way from papilla to lens, or may extend only part of the way. It is then thrown into wave-like motions by the motions of the eyeball, and is easily recognized w^ith the ophthalmoscope. It does not usually cause any disturbance of vision. Detachment of the Vitreous Humor from the Retina, although probably a common diseased condition, cannot as yet be recog- "^ Archives of Ophthalmology, 1880, p. 219. THE VITREOUS HUMOR. 363 uized with certaiuty during life, and rarely becomes the imme- diate cause of blindness. Its danger lies in its liability to bring about detachment of the retina. Detachment of the vitreous may be either idiopathic or due to trauma. In the idiopathic cases chronic choroiditis is the primary disease, which gives rise to a change in the fine con- nective tissue elements of the vitreous, with consequent shrinking of this body. Yet, with the ophthalmoscope, the choroid may seem normal; and, moreover, although floating opacities may be present in the vitreous chamber, yet it is quite possible for a perfectly clear vitreous to be detached.* The condition occurs in connection with high degrees of myopia, where choroiditis is also common, and is probably the most important factor in the production of the detachment of the retina so frequent in these eyes. Anterior staphyloma, hemorrhages into the vitreous humor, and neoplastic growths between the vitreous and retina, also give rise to detachment of the vitreous. With regard to traumatic cases, all perforating injuries attended with loss of vitreous, including cataract operations — and sometimes, when the wound is in the sclerotic, without loss of vitreous — are liable to be followed by detachment of the vitreous. I havef recorded a Fig. 126. case in which detach- ment of the vitreous was the chief lesion in the eye, and was the cause of blind- ness, the vision being reduced to perception of light. The detachment had probably been brought about by an idiopathic hemorrhage from the ciliary body into the ante- *Nordenson, Die Netzhautahlosiing (Wiesbaden. 1887). t Trans. Ophthal. Soc, 1882, p. 41. 364 DISEASES OF THE EYE. rior part of the vitreous. It lay (Fig. 126) immediately behind the lens, and in contact with it, and presented the appearance of a grayish opacity, much like a detached retina, but for the absence of retinal vessels. Suspicion of an intraocular tumor existing, the eye was removed. The vitreous lay against the ciliary body and lens, while the vitreous chamber was filled with serous fluid, and the retina was in its normal position. In the retina toward the ora serrata there were a few minute hemorrhages. CHAPTER XV. DISEASES OP THE RETINA. Purulent 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, in the latter condition, a fatal sign. In an early stage, the Ophthalmoscope shows a number of small hemorrhages in the retina, with general cloudiness of the retinal tissues, while the actual embolisms, which are usually multiple, may not be visible. The inflammation makes rapid progress, soon destroying sight, and extending to the choroid, iris, and vitreous humor, until finally panophthalmitis is reached. The retina is some- times alone the primary seat of the embolic attack, and some- times the choroid is also involved. The embolisms are often little more than masses of micrococci. The retina becomes secondarily implicated in many purulent processes which commence in other parts of the eye. Hemorrhagic Retinitis. — In this affection the retina contains a number of small hemorrhages. They occur chiefly between the fibres of the inner layer, and consequently present a flame- like appearance as seen with the Ophthalmoscope. Any which lie in the outer layers are most apt to be round or irregular in shape. In addition to the hemorrhages, there is diff*use opacity of the retina, and sometimes white spots of degeneration. The papilla is often much swollen, and the retinal veins distended and tortuous, while the arteries are small ; but these appear- ances, as well as the number of the hemorrhages, vary much in diflerent cases. When there are but few hemorrhages, they are situated in the neighborhood of the papilla and macula lutea. 365 366 DISEASES OF THE EYE. The appearances occasionally resemble those of albuminuric retinitis, but in the latter, as a rule, the proportion of white spots to hemorrhages is greater than in this affection. Causes. — The affection is found most commonly in connection vvith cardiac disease, e. g., valvular insufficiency, and hypertro- phy of the left ventricle; or, with diseases of the vascular sys- tem, e.g., atheroma, and aneurisms of the large vessels. Where it is due to disease of the coats of the arteries, the ophthalmo- scope will occasionally reveal an arterial branch altered to the appearance of a white thread ; but, usually, the degenerative change does not interfere with the transparency of the vascular coats. In the majority of cases dependent on cardiac or vascular disease the retinal affection is monocular. This, and the fre- quently sudden onset of the retinitis, lead Leber'*' to think that some second factor for its occurrence exists, probably multiple embolisms of the small branches of the central artery. Suppres- sion of menstruation or other wonted discharge — such as that from piles — has been observed as a cause of hemorrhagic retinitis. A peculiar form of hemorrhagic retinitis is sometimes asso- ciated with secondary syphilis. In addition to the usual opacity of the retina in syphilitic retinitis (vide infra), a portion of the retina is covered with numbers of small round hemorrhages lying in the different layers of the retina, while a connective tissue development is occasionally found in the nerve-fibre layer, in the form of white stride along the course of the blood- vessels. The disturbance of vision is considerable, especially if the neighborhood of the macula lutea be much involved. The Prognosis is bad in severe cases of hemorrhagic retinitis. Relapses are common, while the ultimate tendency is toward atrophy of the retina and papilla. In very mild cases recovery may come about. The Treatment must be chiefly expectant, or directed, at * Graefe und Sremisch's Handhuch, Bd. v, p. 570. THE RETINA. 367 most, toward procuring rest for the general system, or for the organ primarily at fault. Dry cupping on the temple, hot foot-baths, and iodide of potassium internally may be employed. Apoplexy of the Retina. — This differs from the last-described disease in that the hemorrhages are found in a retina free from other diseased appearances, especially from ret- initis. With the Ophthalmoscope, the extravasations of blood appear as red, or almost black, spots of various sizes and shapes. Their number and position in the fundus are also variable. They may be in any layer of the retina, and may sometimes burst into the vitreous humor, and sometimes become extravasated between the retina and choroid. Vision is interfered with according to the position and extent of the hemorrhages. Wherever an apoplexy be situated the function of the retina at that place is suspended. If it be at the macula lutea, central vision will be seriously impaired ; while the scotoma produced by an apoplexy at the periphery of the fundus may pass unnoticed by the patient. Causes. — Retinal apoplexies are most common in advanced life, with atheroma of the blood-vessels, and are then valuable as a warning of possibly impending cerebral mischief Other causes are : hypertrophy of the left ventricle ; suppression or irregularity of menstruation, or at the climacteric period ; the sudden reduction of tension of the eyeball after iridectomy for glaucoma ; the gouty diathesis (Hutchinson) : progressive pernicious anaemia, or anaemia from loss of blood (hsemateraesis, etc.), or from exhausting diseases. In connection with this latter cause of retinal apoplexy, Stephen Mackenzie has pointed out"^ that when the corpuscular richness of the blood falls below 50 per cent., whatever the cause of the anaemia, the tendency to retinal hemorrhage is present. In young people of both sexes, from the fourteenth to the "^ Trans. Ophthal Soc, Dec. 13th, 1883. 3(58 DISEASES OF THE EYE. twentieth year of age, large retinal apoplexies, which may extravasate into the vitreous humor, are sometimes seen, and it is difficult to assign a cause for them. Some of the subjects are weak or anaemic, while many of them are in perfect health. Neither Eales* nor Niedent have found these apoplexies in young women, but this does not conform with my experience, nor with that of many others. Prognosis. — The apoplexies are observed, in the course of weeks or months, to become paler and smaller, often leaving after them choroidal changes, or grayish spots dependent on degeneration of the retina, and in some extreme cases atrophy of the whole retina may result. Occasionally, absorption of the hemorrhages is accompanied by complete restoration of vision, but usually the scotomata remain. Recurrences of the hemorrhages are very common. Glaucoma comes on as consecutive to retinal apoplexies in some instances, and is then known as hemorrhagic glaucoma, an incurable form of the disease (p. 307). In other cases the hemorrhage, having invaded the vitreous humor, gives rise to dense permanent opacity in it, followed, perhaps, by detachment of the retina. Treatment. — Active measures are of little use. Cold com- presses at first, with a pressure bandage, and dry cupping to the temple, may be employed. The general state of the patient must be attended to, and no violent muscular efforts per- mitted. Retinitis Albuminurica occurs as a complication in many cases both of acute and chronic nephritis, and in the albu- minuria of pregnancy. It is most common with the small granular kidney, but may attend any chronic form of Bright's disease. The Defect of Vinon in the chronic form, although often an early or even the first symptom, is never associated with an early * Ophthal. Review, 1882, p. 41. tBerichtd. Ophthal Gesellsch., 1882. THE RETINA. 369 stage of the kidney disease, but rather with a late stage of it, and with dilated left ventricle. Both eyes, as a rule,* are affected, although often not equally so ; vision is much lowered, and even perception of light may be wanting ; but the blindness is not always all due to organic changes in the retina, being often largely the result of urcemia. Ophthalmoscopic Appearances. — These are venous hyperemia and swelling of the papilla, and of the retina in its neighbor- hood ; hemorrhages 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 from it. These changes take place in the order in which I have enumerated them. The hypertemia and engorge- ment of the veins, often very great, become less according as the white spots become more developed. Xear the macula lutea no very coarse changes usually occur, but fine white dots are found, with a star-like arranorement converdno^ toward the macula. 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 formerly know'n as " congestion papilla" in cases of intracranial tumor, 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 hemorrhages are also liable to great variation. Detachment of the retina has been observed in a few cases, and in some the hemorrhages burst into the vitreous humor. Some of the white spots are caused by fatty degeneration of the outer layers of the retina (the retinal vessels passing over them), others by hypertrophy of the nerve-fibre layer (the retinal vessels hidden by them). The fine dots about the macula * A few cases are recorded in which only one eye was attacked, and in several of these it was found that but one kidney was present. 370 DISEASES OF THE EYE. lutea are the result of fatty degeneration of the inner ends of Miiller's fibres. The connection between the renal and retinal affections is not known with certainty, but the theory that the latter is due to chronic uncmia is probably correct. Prognosis. — In these cases the prognosis as regards the patient's life is bad ; but if the general disease remain sta- tionary, or improve, or recover, the retinal changes may im- prove or disappear, and leave the retina with normal appear- ances and functions; or the swelling, hypersemia, white spots, and hemorrhages may give place to optic atrophy, with diminution in size of the arteries, pigmentary alterations in the retina, and blindness. Treatment. — Dry cupping at the temple is about the only remedy which can be employed directly for the retinal affection, and I will not say that it is of much use. Taking into consider- ation 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. Retinal Affections in Diabetes. — There is no one condition of the retina characterist*ic of diabetes, although undoubtedly retinal affections occasionally do complicate it in an advanced stage. Small retinal hemorrhages with fine changes, in the form of glistening dots about the macula lutea, somewhat similar to the starlike appearance in Bright's disease, form perhaps the most common and suggestive appearances. In other cases retinal hemorrhages alone are found, and in others hemorrhagic retini- tis ; while again, the so-called typical appearances of Bright's disease may be presented. There are often opacities of hemor- rhagic origin in the vitreous humor, and iritis may come on. Leber lays down the important rule that in all cases of retinal hemorrhages and of retinitis hemorrhagica the urine should be examined for sugar. Retinitis Leucaemica. — In not more than one-third or one fourth (Leber) of the cases of leucocythemia does a retinal THE RETINA. 371 affection occur, and it is not always of the same type. It may consist in a slight diffuse retinitis, accompanied by some extra- vasation of pale blood, while the blood-vessels are also pale, the veins being much distended, and the arteries small, and the choroid of an orange-yellow color. Or, it may resemble a case of ordinary hemorrhagic retinitis. The Appearances most characteristic of the affection are : the papilla pale, with indistinct margins; slight opacity of the retina, especially along the vessels ; small hemorrhages ; round, white, elevated spots, up to 2 mm. in diameter, with a hemor- rhagic halo, situated by preference toward 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 leuc?emic blood, the result, Leber thinks, of diapedesis. Vision may be but little affected if the macula lutea be fairly free. Hemorrhage into the vitreous humor may cause complete blindness. Syphilitic Retinitis (or Syphilitic Choroido-Retinitis). — Inherited, or acquired, constitutional syphilis is liable to in- duce a form of chronic diffuse retinitis. In the acquired disease it is a later secondary symptom, coming on between the sixth and eighteenth month, often only in one eye. With the Ophthalmoscope a light opacity of the retina is seen extending from the papilla some distance into the retina, and very gradually disappearing toward the equator of the eye. The papilla is but slightly hypersemic, while its margins are indistinct, like those of the moon seen through a light cloud. The artery is not generally altered, and the vein but slightly distended. Opacities in the vitreous humor are not uncommon. They may be membranous or thread-like, but a diffuse dust- like opacity, filling the whole vitreous humor, is almost pathog- nomonic of a syphilitic taint, and may create much difficulty in the ophthalmoscopic diagnosis of the retinal affection. Disseminated choroidal changes, in the form of small yellowish spots with pigmentary deposit, are very frequent, especially 372 DISEASES OF THE EYE. toward the equator of the eye. Many observers, indeed, hold that the whole process is primarily in the choroid, and that the retina is only secondarily affected. Fine whitish dots and pigmentary changes often occur about the macula lutea. Vision may be but slightly affected, but in the advanced stages it is usually much lowered. Central or peripheral scotoraata, or concentric defects of the field, are found. The scotomata 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 (metaraorphop- sia) of their outlines. The micropsia is believed to be due to a separation from each other of the elements of the layer of rods and cones, by subretinal 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 choroiditis. But if the cases come under suitable treatment in an early stage, a cure may often be effected. Treatment. — The only remedy which is of real value is mer- cury, and that in an early stage. It should be used in a pro- tracted course of some weeks by inunction, combined at discretion with small doses of calomel internally. Perchloride of mercury hypodermically, in -^ gr. doses once a day, is also a suitable measure. If mercurialization be effected, it should not go further than a very slight stomatitis. Pilocarpine hypodermically, Turkish baths, and the artificial leech at the temple may be em- ployed as adjuncts to the treatment. When the mercurial course has been completed iodide of potassium should be prescribed as an after-treatment. THE RETINA. 373 Quinine Amaurosis. — Quinine in large doses, and very occa- sionally in small doses, is liable, in some individuals, to cause amblyopia, which may amount to absolute blindness, accom- panied for some hours or days by great deafness. This absolute blindness is never more than temporary, although it may last for some weeks ; but in severe cases concentric contraction of the field is apt to remain permanently, with or without some defect of central vision. In the only instance of this more serious re- sult which I have seen, the color and light-senses, notwithstand- ing the contracted field and marked seeming optic atrophy, were normal ; but the adaptation of the retina, as shown by consider- able night-blindness, was defective. In what may be called the acute stage the Ophthalmoscopic. Appearances are sometimes normal, but pallor of the optic pa- pilla, with scarcity and smallness of the retinal vessels, is the usual condition. Where the case is chronic — the fields remain- ing contracted, although central vision has improved — the ophthalmoscope may discover a very pale optic papilla with minimal vessels. The retinal ischemia is doubtless the immediate Cause of the amblyopia, and, in its turn, 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. Treatment. — Cessation of the use of the quinine. Digitalis in- ternally to raise the arterial tension, nitro-glycerine or inhala- tions of nitrite of amyl, hypodermic injections of strychnia, and general tonic treatment are the means most likely to promote a cure. Retinitis Pigmentosa is a degenerative, rather than an inflam- matory, affection of the retina. It is extremely chronic in its progress, 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 most complained of is night-blindness (nyctalopia = vy$, night; wc'', the eye), due rather to defective power of retinal adaptation than to defective 374 DISEASES OF THE EYE. light-sense. The field of visiion, 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 most important. Finally, the last remaining central region becomes blind. The Ophthalmoscopic Appearances consist in a pigmentation of the nerve-fibre layer of the retina, which commences in the peri- phery, and in the course of years advances toward 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 grayish-yellow color, never white, and the vessels are very small. The choroid is sometimes slightly affected, irregularity in its pigmentation being observable. Pathology. — The pigment in the retina is believed to wander into it from the pigment epithelium layer. The other patho- logical changes in the retina consist in hyperplasia of its con- nective-tissue elements, and thickening of the walls of the vessels at the expense of their lumen. The choroidal vessels, too, are altered,* owing to an endar- teritis, 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 choroid ; 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, the patients being frequently defective in intelligence, or deaf and dumb. Many of them are the offspring * Wagenraann, A. v. Graefe's Archiv, xxxvii, 1, p. 2:J0. THE RETINA. 375 of marriages of consanguinity, and in others an inherited syphi- litic taint is present, while in others no cause can be assigned. Treatment is of little use. At best, one may stimulate the torpid retina by hypodermic injections of strychnia or with the continuous current. The latter means has found an advocate in Dr. Gunn,* and I have seen several cases in which temporary benefit was obtained from it. Retinitis Punctata Albescens (Mooren) ; Retinitis Centralis Punctata at Striata (Hirschberg). — A few cases of this peculiar aflTection have been described.f These have occurred in middle- ^ged or elderly people whose general health was good, or, if dis- ordered, was not similarly so in any two cases. The defect of vision may come on rapidly, or may be gradually developed in the course of many years. It consists in a lowering of the cen- tral vision, with positive or relative scotoma, or both may be present ; but the eccentric field remains intact. The Ojyhthalvioscope discovers great numbers of minute, white, glistening dots and fine, white striae in the retina, chiefly between the papilla and macula. A retinal hemorrhage was noted in one case, and in only one was slight papillitis present. The aflTection is probably of inflammatory origin. Treatment consisted in Heurteloup's leech, iodide of potassium, protection of the eyes, and care of the general health. Cure took place in one case, while in no instance did serious blindness come on. Development of Connective Tissue in the Retina, or Retinitis Proliferans. — Extensive white striae, formed of connective tissue, are sometimes seen in the retina, and may even conceal the ves- sels and papilla. They are the result of hemorrhages according to Leber, and of an inflammatory process according to Manz. Hemorrhages in the retina or in the vitreous humor, or in both, are generally present at some period (p. 366). Vision is often * Ophthal. Hosp. Rep., vol. x, p. 161. t Mooren, "Funf Lustren Ophthalmologischer Wirksamkeit," p. 216. Hirschberg, Centralblatt f. prak. Augenheilkunde, 1882, p. 330. 376 DISEASES OF THE EYE. but slightly affected, but the danger of recurrent intraocular hemorrhages renders the ultimate prognosis bad, as a rule. Treatment. — Heurteloup's leech. Iodide of potassium or per- chloride of mercury. Protection spectacles. Detachment of the Retina. — This condition consists in a sepa- ration of the retina from the choroid, the intervening space being 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 choroid. If the media be clear, and the detached portion extensive, the diagnosis is not difficult. The OpJithalmoscojye shows a grayish reflex from a position in front of the fundus oculi, and to the surface from which the re- flex is obtained a wave-like motion is imparted -svhen the eyeball is moved. Over this grayish surface the retinal vessels run, and they serve to distinguish a detached retina from any other dis- eased condition with a somewhat similar appearance. They seem black, not red, in consequence of absorption of the transmitted light, and are hidden from view here and there, in the folds of the detached retina. In many cases a rent in the detached retina, through which the choroid can be discerned, will be discovered. The detachment may commence in any portion of the fundus, but most commonly 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 de- tached having become replaced. The diagnosis is more difficult if there be but little fluid behind the retina, or if there be opaci- ties in the vitreous humor. Vinon is affected according to the position and extent of the detachment. Central vision may be quite normal if the macula lutea and its immediate neighborhood are intact. The patients complain of seeing objects distorted, of a black veil which seems to hang over the sight, and sometimes of black, floating spots be- fore the eye, due to opacities in the vitreous humor. These symptoms often come on suddenly in an eye which has hitherto had good sight. THE RETINA. 377 The field of vision, ou examination, will show a defect corres- ponding to the position of the detachment. If, for example, it be below, the defect will be in the upper part of the field. If the detachment be fresh, the retina not having yet undergone secondary changes, and if the quantity of subretinal fluid be not great, the defect may only amount to an indistinctness of vision ; but, later on, when infiltration and connective tissue degenera- tion of the detached part come about, fingers may not be counted at the same place. The phosphenes"^ of the detached portion are wanting. Should the detachment become complete, little more than power of perception of light may be present. Total detachment is followed by cataract, and often by iritis and phthisis bulbi. The detachment may remain stationary, and not extend to the whole fundus, or the retina may return to its normal position. Such a happy result, however, is most rare. Causes. — Myopic eyes — which we know are so frequently affected with choroiditis and disease of the vitreous humor — are those most subject to detachment of the retina, 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. Some punctured wounds of the sclerotic, also, in the course of healing, by dragging on the retina, give rise to it. Choroidal tumors, especially those situ- ated in the posterior segment of the fundus, usually cause de- tachment in an early stage of their growth, and the complication renders their diagnosis more difficult (p. 257). * Phosphene is the subjective sensation of light experienced when the eyeball is pressed upon. For clinical purposes it is best tested by gentle pressure with a blunt point (head of a bodkin, or large sized probe) applied to the eyeball through the eyelid. The phosphene of any region is tested by applying pressure to that part of the globe ; thus, if in a healthy eye the individual look down, and pressure be applied to the upper part of the globe through the eyelid, the phosphene will be seen appearing below, but if there be a detachment of the retina at the place pressed on no phosphene is seen. 32 378 DISEASES OF THE EYE. Leber* observed that in non-traumatic detachment a perfora- tion or rent in the detached portion is very frequently to be seen with the ophthalmoscope, and holds that it is probably al- ways present, although sometimes, from being hidden behind a fold of the retina, it cannot be found. He was led from this, and from his pathological investigations and experiments upon ani- mals, to think 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 hya- loid had become adherent from the inflammatory process — a rent was produced in the retina by the shrinking process in the vitre- ous. And he concluded that through this rent the fluid, which is always present behind the vitreous in cases of detachment of that body, makes its way behind the retina and separates the latter from the choroid. All this has been fully borne out by Nordenson's pathological researches,'}" who has ascertained, moreover, that disease of the ciliary body and choroid 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 humor consists in an alteration in its connective tissue elements, resulting in the deleterious shrinking. Treatment. — Evacuation of the subretinal fluid by puncture of the sclerotic was first proposed by Sichel, and has been culti- vated by de Wecker. He uses an instrument like a broad needle, with a sharp point and two blunt edges, which is entered through the sclerotic and choroid at a place corresponding to the position of the detachment, but not so deeply as to reach 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 orbital muscles, so that the cho- *Berichtd. Ophthal. Gesellsch., 1882, p. 18. t "Die Netzhautablosung " (Wiesbaden, 1887). THE RETINA. 379 roidal vessels may be injured as little as possible. A firm band- age is applied, and the patient kept in bed for eight or ten days. The dorsal position in bed, with a pressure bandage on the eye, maintained for from four to six weeks, has produced reposi- tion of the detachment in some cases. The method, if properly carried out, is most trying to the patient. The few cures which have been reported as accomplished by these means probably depended upon the retina again coming in contact with the choroid, and, owing to some slight inflammatory process, adhering to it. For the most part the cure is only tem- porary, and in such cases we may suppose that no adhesion sprang up, but that the temporary cure was due to a return of the subretinal fluid, through the hole in the retina, to its original position between the retina and vitreous. Soon, however, it makes its way back again through the hole, and the detachment recurs. Schoeler* injects tincture of iodine into the vitreous humor in front of the detached retina, in order to press it back to the choroid and to produce a plastic choroido-retinitis, which may unite the two coats. He has reported several good results by this method, but some who have tried it have experienced vio- lent inflammatory reaction in the eyes operated on, with dis- astrous consequences. Grossmannf tried aspiration of the subretinal fluid, with simultaneous increase of the pressure in the vitreous humor, by injections into the latter of four or five drops of an indifferent fluid, namely, a 0.75 per cent, lukewarm solution of common salt. The results obtained were encouraging in the three cases treated, but I am not aware of any further reports. Galezowski j simply aspirates the subretinal fluid. * " Zur operativen Behandlung und Heilung der Netzhautablosung " (Berlin, 1889). t Ophthalmic Review, 1883, p. 89. X Recueil d^ Ophthalmologic, Mars, 1888. 380 DISEASES OF THE EYE. Pilocarpine, used hypodermically, has been praised by some as a mode of treatment, as, also, salicylate of sodium internally. Formerly an active mercurial treatment used to be employed, with the object of obtaining absorption of the fluid. The Prognosis of every case of detached retina is bad, spon- taneous cure being extremely rare, and the treatment of the dis- ease remaining one of the weakest points of ophthalmic thera- peutics. Moreover, both eyes are often affected, one after the other. The cures by any one, or by any combination of the above methods of treatment, are few and far between ; and when, sometimes, the retina does return to its place, there is still the danger of a recurrence of the detachment. The most favorable cases are those due to choroiditis ; the most unfavorable those due to posterior staphyloma. Cysticercus under the Retina. — The cysticercus of the taenia solium in the eye is extremely rare in these countries, but not so in Germany. Its most frequent seat is between the retina and choroid, where it is recognized 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 cor- responds with the head of the entozoon. Wavelike motions along the contour of the cyst should be looked for, to confirm 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 humor, and are almost characteristic of the presence of cysticercus. The entozoon may become encapsuled behind the retina, or it may burst into the vitreous humor (p. 362) ; and, finally, chronic iridocyclitis, with total loss of sight and phthisis bulbi, is apt to come on. Treabnent. — We are not acquainted with any anthelmintic 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 when the position of the cysticercus admits of it. By a well-placed THE RETINA. 381 puncture through the sclerotic and choroid the entozoon may then be evacuated. Aneurism of the Central Artery of the Retina. — Only two cases * of this are recorded as having been observed during life, ajid these were in men aged respectively twenty and forty. In one of these cases there were also extensive connective tissue changes in the retina, the veins were dilated in places, and only one eye was affected. The minute aneurismal dilatations were globular and situated laterally on the vessels, or they were fusi- form and involved the whole of its lumen. The number of aneurisms in an eye varied from three to nine. Neither case was followed to its end ; but it is to be presumed that such eyes would run great risk of being ultimately lost through intra- ocular hemorrhage. A rational Treatment for the condition can hardly be devised. Embolism of the Central Artery of the Retina. — Sudden or very rapid blindness, beginning at the periphery of the field and advancing toward 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 empty of blood, resembling fine white threads, and the veins are diminished in size at the papilla, but increase somewhat toward the periphery. Pressure on the eyeball produces no pulsation nor change in calibre of the vessels, as it does in a sound eye. Usually on the following day the central region of the retina begins to assume a grayish-white, opaque appearance, consequent on disturbance of nutrition, in the midst of which the macula lutea is seen as a purple-red spot. The little blood contained in the vessels may soon be seen divided into short columns with colorless interspaces, and these move along the vessels with a slow, jerky motion. Minute hemorrhages often occur, most commonly between the macula and the papilla. * Story and Benson, Trans. Ophthal. Sac, 1883, p. 108 ; and Perinow, CentralhLf. AugenheilTcunde, 1883, p. 392. 382 DISEASES OF THE EYE. The peculiar appearance of the macula lutea is certainly not due to hemorrhage. According to Liebreich it is merely a con- trast effect, the red color of the choroid shining through where no nerve-fibre layer is present. Leber suggests that the color may be due to the retinal purple. The infiltration of the retina passes away in a few weeks, and also the peculiar appearance of the macula lutea, while atrophy of the retina and papilla usually supervene. Embolism of a branch only of the central artery has been observed. In these cases the infiltration and the defect of vision are confined to the part of the retina supplied by the embolized branch. Prognosis. — Vision may improve for a time, but when atrophy commences it falls back again, and, finally, power of perception of light is lost. Cases of embolism of a branch are more likely to recover. Causes. — Endocarditis ; mitral disease ; atheroma of the large arteries of the body; aneurism of the aorta; pregnancy; Bright's disease. Two cases of chorea with embolism of the central artery are recorded.* But it is said also to occur in healthy persons without any discoverable cause. Treatment. — Repeated paracentesis of the anterior chamber has been tried, and also iridectomy, with the object of reducing the tension, and in this way promoting a collateral flow of blood, by means of the only ascertained (Leber) communications betw^een the retinal and choroidal vascular systems; namely, at the entrance of the optic nerve.f These attempts have been unsuccessful. * H. R. Swanzy, R. L. 0. H. Reports, September, 1875 ; and A. Benson, Ophihal. Review, January, 1886. t Gowers (" Manual of Medical Ophthalmoscopy," p. 31) is of opinion that there are other anastomoses between these systems, probably by connection with the long ciliary arteries. A cilio-retinal vessel passing from the choroid or sclerotic at the papilla to the region of the macula lutea is not an uncommon vascular anomaly ; and Benson has published a case of embolism [Ophihal. Hasp. Rep., vol. x, p. 336) in which the THE RETINA. 383 Several cases have been published, in which the circulation, which probably was not completely impeded by the embolus, 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. So long as the pressure was maintained, a column of blood was being stored up behind the embolus, and, on removal of the pressure, rushed forward against the impedi- ment, carrying it into some more remote vessel or into the general vascular system. In fresh cases, massage of the eyeball suitably applied would therefore always be worth the trial. Thrombosis of the Retinal Artery. — Blocking of the artery may occur spontaneously, from thrombosis due to failure of the heart's action and slowing of the arterial flow, the result, in its turn, of cardiac disease, spasm of the blood-vessels, disease of the walls of the vessels, or alterations in the quantity and amount of blood. The Ophthalmoscopic Signs are in all respects similar to those of embolism. The Diagnosis between thrombosis and embolism of the central artery can only be made by certain symptoms which precede or accompany the attack in thrombosis, but are want- ing in embolism. These are : previous attacks of transient blindness in the blind eye, a simultaneous attack of blindness in the fellow eye, and faintness, giddiness, and headache at the onset of the blindness. Treatment. — When transient attacks of blindness are com- plained of, it is important to overhaul the patient's general state, and to correct, so far as possible, any condition which might be the cause of feeble circulation. When the true attack comes on, manipulation of the eyeball applied immedi- presence of such an artery seemed to have a favorable influence for the progress of the case, good central vision being recovered, although the field remained concentrically contracted. 384 DISEASES OF THE EYE. ately, or paracentesis of the anterior chamber, might prove of use. Glioma of the Retina. — This is a malignant growth, which is found almost exclusively in young children,* and may even be congenital. Owing to the age of the patients, the incipient stages of the disease are seldom observed, for they are un- attended by pain or inflammation. The growth commences as small, white, 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 be- come detached at an early period, but there are exceptions to this, especially when the disease starts from the nerve-fibre layer. In the early stages there is no iritis, cyclitis, or opacity of the vitreous humor, and the iris periphery is not retracted — points which especially enable us to distinguish it from pseudo-glioma (vide Purulent Inflammation of the Vitreous Humor, Chap. XIV, p. 367). 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 to glioma of the brain. When the tumor has filled the eyeball it bursts out- ward, usually at the corneo-sclerotic margin, and then grows more rapidly, and often to an immense size, as a fungus h?ema- todes. 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 choroid (p. 258), when the latter occurs in young children, is sometimes diflficult or impossible, but, in view of treatment, not of great importance, as in either case the eye must be enu- cleated. Treatment. — 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, to divide the * A case of Glioma Retinae in a man aged twenty-one is reported by Mervill, in the Trans. American Ophihal. Soc, vol. iii, p. 364. THE RETINA. 385 nerve as far back as possible, and if the orbital tissues be al- ready diseased to remove all suspicious portions of thera. Blinding of the Retina by Direct Sunlight.— This is especially likely to occur on the occasion of solar eclipses by observation with unprotected eye. Immediately after the exposure, the patients complain of a dark or semi-blind spot in the centre of the field of vision ; a positive scotoma, in short, which may even be absolute, and which interferes with vision in proportion to the length of the exposure. Objects may also seem twisted or otherwise distorted. The Ojihthalmoscojye shows a small, bright, white spot at the fovea centralis, surrounded by a blood-red ring, which shades off into the normal color. When the cases are not severe im- provement in vision takes place, but complete recovery is not common. Czerny, and also Deutschmann,'^ demonstrated that concentra- tion of the direct rays of the sun on the rabbit's retina gives rise to coagulation of the retinal albumin, with vascular reaction, dia- pedesis of blood corpuscles, and pigmentary disturbances ; and it is probable that the changes in the human retina produced by exposure to direct sunlight are of similar nature. This accident is not analogous to snow-blindness (Chap. XVII). Treatment — Hypodermic injections of strychnia, the constant galvanic current, and dry cupping on the temple afford the best chances for promoting the cure. Dark protection spectacles should be worn. Neurasthenic Asthenopia, or Retinal Anaesthesia. — This pecu- liar and rather rare affection is one about which we have still much to learn. It is a complex of eye-symptoms in connection with a debilitated state of the general nervous system, the eye itself being organically healthy. These Symptoms are — 1. Di- minished, but fluctuating, acuteness of vision. The effort or desire to see well is often the signal for the acuteness of vision to * J. V. Graefes Arcliiv, Bd. xxviii, Abt. 3, p. 241. 386 DISEASES OF THE EYE. fail. 2. The rapid disappearance of objects from view, if looked at too long. 3. Attacks of defective sight, with positive scoto- mata coming on suddenly and without provocation, and lasting for a few minutes. 4. Apparent contraction of the field of vision. If a perimetrical examination be made the field will be found contracted ; but, as Wilbrand"^ has pointed out, this con- traction is merely a sign of retinal exhaustion, as indicated by the fact that the longer the examination is continued the more contracted does the field become. 5. Optical impressions are retained but a short time. The appearance of persons, places, etc., is not remembered when seen soon again. 6. Muscular asthenopia. Insufficiency of the internal recti is often present, as well as defective accommodation. 7. Hypersesthesia of the retina. Dazzling is caused by even moderate light, and strong contrasts of light and shade are distressing, while the acuteness of vision is often improved when blue or smoked glasses are worn. The Ophthalmoscopic Appearaoices are normal, or consist merely of some hypersemia of the optic papilla. The general symptoms of the condition consist in insomnia ; tinnitus; subjective sensations of hearing; exalted, or, again, defective sensations of taste and smell ; sensations referred to the skin, such as formication, itching, burning, numbness, heat, and cold ; great restlessness of body ; depression of spirits ; want of mental energy ; absent-mindedness ; weariness. The persons in whom the affection is most common are children before and at the time of puberty, and women labor- ing under hysteria, anaemia, chlorosis, ovarian irritation, or displacement of the uterus; but it is also occasionally found in men. Treatment. — Any uterine or other local disorder must be relieved, so far as possible. Rest of body and mind is to be enjoined, with fresh air and moderate exercise. Strychnine, hypodermically, is a valuable remedy in the affection, and with * Archives of Ophthalmology^ xii, 428. THE RETINA. 387 it iron and quinine, internally, may be associated, and bromide of potassium with hyoscyamus to promote sleep. In some, especially in hysterical cases, valerianate of zinc is beneficial. Sea-bathing and cold shower-baths, with change of air, are valuable adjuncts of the treatment. Blue or smoked protection glasses are most grateful to the patient and promote the cure, but the spectacle-frames often cause annoyance by their pres- sure on the nose or face. Errors in refraction should be corrected. The Prognosis is favorable, inasmuch as ultimate recovery is assured, but the course of the affection is excessively chronic, extending over months or years, with frequent relapses. Traumatic Anaesthesia of the Retina. — A blow on the eye from a fist, cork from a bottle, etc., is liable to produce con- siderable amblyopia, with concentric contraction of the field, which may continue for a long time, while the Ophthalmoscopic Appearances are normal. Ultimately, these cases usually re- cover, an event which may be decidedly promoted by the use of strychnine hypodermically, but very defective sight sometimes remains permanently. Commotio Retinae, or Traumatic (Edema of the Retina, is the result of a blow upon the eye. Within a few hours after the accident the Ophthalmoscope reveals a white cloudiness of a portion of the retina, usually in the neighborhood of the optic papilla and macula, but sometimes more eccentrically, and sometimes there are two opaque patches. The opacity increases in intensity and spreads somewhat. The retinal vessels remain normal ; there may be some small hemorrhages, and sometimes the papilla is redder than normal. These appearances com- pletely disappear in the course of a few days. Vision is only slightly affected and recovers according as the retinal changes pass off. Hyper aesthesia of the Retina. — The symptoms of this affection are photophobia, lachrymation, and blepharospasm when the patient is exposed to ordinary daylight. There are no Ophthal- moscopic Sig)is. The chief causes are hysteria, long-continued 388 DISEASES OF THE EYE. use of the eyes with very bright objects, and neuralgia of the fifth pair. Treatment consists in removal of the cause, rest of the eyes, and protection from light, with suitable measures for the general health. CHAPTER XVI. DISEASES OF THE OPTIC NERVE. Optic Neuritis. — The Ophihalmoscopie Appearances of inflam- mation of the optic nerve vary a good deal with the intensity of the process. Common to every case is hypersemia and swelling of the papilla, with haziness (" woolly " appearance) of its mar- gins, and increase in the size of the central vein, while 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 distention of the vein is also not continued to the periphery of the fundus. In slight cases these appearances may barely exceed the normal. In extreme instances the papilla is swollen to a great size, and may even assume quite a mushroom shape, while the veins are enormously distended and tortuous, and the arteries are con- tracted so as to be barely visible. Grayish strise, also, extend from the papilla into the surrounding retina, some flame-shaped hemorrhages are present on or near the papilla, and, occa- sionally, white spots in the retina and a stellate arrangement of small white dots about the macula lutea produce an appear- ance which cannot be distinguished from albuminuric retinitis. This extreme form is still sometimes termed Congestion Papilla, or Choked Disc (Stauungspapille'), although the theory which originally suggested the term has been abandoned. Papillitis (Inflammation of the Optic Papilla) is a better term, express- ing, as it does, more truly the pathological condition. The Vision, even in cases where the ophthalmoscopic signs are highly developed, is frequently but little below the normal ; while again in other, and possibly less well-marked cases, it may be reduced to perception of light, or even that may be 389 390 DISEASES OF THE EYE. wanting. These remarkable differences in the degree of blind- ness depend, probably, on the extent to which the nervous elements of the inflamed part are pressed on or altered, and this cannot be gauged by the ophthalmoscopic appearances. Sometimes the field of vision is normal, while again it is concentrically or irregularly contracted, or it may be hemi- anopic. Pathologically, the changes in the papilla consist in venous hypersemia, oedema, hypertrophy of the nerve fibres, infiltration of lymph cells, and development of connective tissue. Inflam- matory 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 Tumor (syphiloma, tubercle, glioma, cyst, and abscess), in par- ticular, is the most common cause, and is, moreover, usually present when the papillitis is of an intense kind (choked disc)* A very small tumor situated anywhere"^ in the brain is capable of producing optic neuritis, although unattended by meningitis. Tubercular Meningitis is the next most common cause. Non- tubercular meningitis occasionally gives rise to optic neuritis, and sometimes, also, cerebro-spinal meningitis does so. Optic neuritis is occasionally associated with acute myelitis,t so that inflammation of the optic nerve, with paralytic phe- nomena, does not exclusively indicate cerebral disease. The Connection between Optic Neuritis and Intracranial Diseases has given rise to much discussion. In cases of tumor, as well as of tubercular meningitis, a considerable exudation of fluid usually takes place into the cavity of the third ventricle. This, along with the pressure of the new '^ Hughlings Jackson {Trans. Ophthal. Soc, vol. i, p. 79), states that optic neuritis has not been noted with tumors of the medulla oblongata. Edmunds and Lawford {Trans. Ophthal. Soc, vol. iv, p. 18.5) find that tumors of the cortical motor area do not commonly produce neuritis, while it is very frequent and severe in tumors of the cerebellum. t Sharkey and Lawford, Trails. Ophthal. Soc, iv, 232. THE OPTIC NERVE. 391 growth, or alone in cases of meningitis, increases the intra- cranial pressure. By reason of this increased pressure, the subarachnoid fluid is believed to be driven into the subvaginal lymph space of the optic nerve, and to produce there that dropsy of the sheath which is found in nearly all these cases on careful post-mortem examination. Leber holds'^ that this fluid is probably an irritant, and, as such, sets up the inflammation, a view which has been corrobo- rated by Deutschmann.f The inflammation, although most intense at the papilla, near which the fluid is collected in greatest quantity in the cul-de-sac formed by the termination of the intervaginal spaces, is not confined to that place, as was believed, but extends up the trunk of the nerve, as microscopic examination reveals. Many observerst state that, in a large number of cases, cere- britis, recognizable only with the microscope, is present, and that an extension of this process down the optic nerve takes place. They have ascertained that the whole trunk of the nerve is involved in the inflammation, and they seem to regard the dropsy of the sheath as of little or no importance in the causation of the optic neuritis. Again, others§ maintain that oedema, but not inflammation, of the optic trunk is conducted from the brain. The view originated by von Graefe, that the extreme form of papillitis, called by him Stauungspapille (Choked Disc), is due to obstructed outflow of blood through the retinal vein, is now abandoned. Other causes for Optic Neuritis are : — Hydrocephalus. — Here the pathogenesis is probably the same * Trans. Inter. Med. Congress, 1881, vol. iii, p. 52. t "Ueber Neuritis Optica" (Jena, 1887). X S. Mackenzie, Brain, vol. ii, p. 257. W. Edmunds, Trans. Ophthal. Sac, vol. i, p. 112. Brailey, Trans. Internat. Med. Congress, 1881, vol. iii. p. 111. I Olrich, Archives of Ophthal., xviii, p. 65. 392 DISEASES OF THE EYE. as in the foregoing, but the occurrence of optic neuritis is, on the whole, not very common in this connection. Tumors of the Orbit. — The path by which these growths bring about papillitis is still unknown. Inflammatory Processes in the Orbit, such as caries, inflam- mation of the retro-orbital areolar tissue, erysipelas of the head and face extending to the orbital tissues, and periostitis. The presence of the latter may often be recognized by pain on motion of the eyeball, pain in the eye and forehead, and especially by pain on pressure of the globe backward, 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. Exposure to Cold, especially if the skin be heated and per- spiring. Suppression of the Menstruation. — If, during the menstrual period, the flow be arrested by exposure to col-d, wet feet, etc., acute optic neuritis with rapid blindness may come on. Spon- taneous amenorrhoea, or even irregularity of menstruation, and the climacteric period are liable to have a similar, but more chronic, result. Nothing is definitely known with regard- to the connection between the uterine and ocular disorder, but it is believed that the latter is due to " determination of blood " taking place to the base of the brain, instead of to the uterus. In these cases the Ophthalmoscopic Appearances, as well as the blind- ness, are apt to be extreme. Treatment here should be directed chiefly to restoring the normal uterine functions. Hot foot-baths and Heurteloup's leech to the temples are of use. Chlorosis. — Here optic neuritis often is present, due to the dis- ordered state of the blood, and usually yields under the influence of iron. Syphilis. — The trunk of one or both optic nerves may be the seat of specific inflammation in connection either with congenital THE OPTIC NERVE. 393 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 inoculation. The Ophthalmoscopic Appearances maybe normal (retro-bulbar neuritis), or may present any grade of neuritis, even to the most pronounced papillitis. In the latter case it \yould not be possible to say whether the papillitis be a primary one, or due 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 mercurialization. By this treatment, 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. Later on, iodide of potassium is indicated. 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. Rheumatism. — There is no doubt whatever but that the rheumatic diathesis is occasionally the cause of optic neuritis, although the fact is not unreservedly accepted by every author. Other manifestations of rheumatism are sometimes well marked, but may be slight, e. g., in a case which I saw, neuralgia of the face and head in damp weather, and even with a shower of rain, was the only other sign of rheumatism. One or both optic nerves may be attacked. The Opjhthalmoscopic Appearances often amount to extreme papillitis, but in many cases fall short of this. If the case come early under suitable treatment, the Prognosis is fairly favorable ; but when the inflammation is of some stand- ing, consecutive optic atrophy must be feared. The Treatment consists of full doses of salicin, salicylate of sodium, iodide of potassium or of sodium, Turkish baths, and other recognized anti-rheumatic measures. Lead-Poisoning. — In some cases of lead-poisoning, optic neu- 394 DISEASES OF THE EYE. ritis, not to be distinguished from that of primary cerebral affections, is found. Sometimes the Ophthalmoscopic Appear- ances are very slight, and again quite pronounced, the changes extending into the retina, and stimulating the retinitis of Bright's disease, and, in such cases, renal disease is likely to have much to do with the causation of the retinitis. Indeed, there are those who, w^ith 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, to effusion into the ventricles of the brain and subarachnoid space, or to suppression of menstrua- tion. Occasionally, optic atrophy is the first ophthalmoscopic appearance seen, but it is probably consecutive to retro-bulbar neuritis, as shown by white strise (perivascularitis) along the vessels. The Vision is often much affected, and it is stated that sudden complete blindness 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. The Diagnosis depends entirely on the presence of the other well-known symptoms of lead-poisoning, the ophthalmoscopic appearances presenting nothing pathognomonic. The Treatment is that for general lead-poisoning, or for the immediate cause of the neuritis. Multiple Sclerosis. — In these cases the inflammation is very ephemeral, and rapidly gives place to atrophy. Uhthoff states that it occurs in about 13 per cent, of the cases of this disease. Hereditary and Congenital Predisposition. — It has been observed that optic neuritis, without immediate cause, may attack several members of a family, and that the tendency to it may extend over several generations. Jt makes its appear- ance in these instances about the eighteenth or twentieth year of age, and confines itself almost exclusively to the males. The patients may be perfectly healthy in all other respects, but many of them suffer from other affections of the nervous THE OPTIC NERVE. 395 system. Both eyes are affected, the defect of vision being a central amblyopia, from which recovery is rare ; but yet, although the ophthalmoscopic appearances gradually become those of atrophy, the peripheral portions of the field retain their functions. As to the Treatment of these cases due to hereditary and congenital predisposition,"^ Mooren employs a seton in the back of the neck in the early periods, and, later on, nitrate of silver internally. Leber has found benefit from a mild course of mercurial inunctions. The two following diseases. Chronic Ketro-bulbar Neuritis, or Central Amblyopia, and Optic Neuritis with Persistent Dropping from the Nostril, must be treated of separately, owing to the well- defined etiology of the one and the peculiar symptoms of the other. Chronic Retro-bulbar Neuritis, or Central Amblyopia (Toxic Amblyopia). — Until within recent years, it was not clearly known whether these two terms should be applied to one and the same disease, or whether we had to deal here with two distinct processes. There is a class of cases which were ad- mittedly due to an inflammatory process in the trunk of the nerve, the causes and symptoms of which were very similar to those of central amblyopia, while there was strong presump- tive evidence that the latter affection, often known as Toxic Amblyopia, was due to a retro-bulbar inflammation ;. but direct proof of the fact was wanting. Thanks to late investigations,"^ there is now no doubt but that we have here to deal with only one disease. Symptoms. — The affection of vision often comes on rather * Mooren, Ophthal BerichL, 1867, p. 305, and 1874, p. 87; and Funf Lustren Ophthal. WirJcsamkeit, 1882, p. 248. Norris, Tratis. Amer. Ophthal. Soc, 1884, p. 662. * Samelsohn, A. v. Graefes Archiv, xxviii, pt. 1, p. 1. Nettleship and Walter Edmunds, Trans. Ophthal. Soc, vol. i, p. 124. Uhthoff, von Graefes Archiv, xxxii, p. 4. Sachs, Archiv of Ophthal, xviii, p. 133. 396 DISEASES OF THE EYE. rapidly. The patient may complain of a glimmering mist which covers all objects, especially in a bright light, and the acuteness of vision is reduced. The patient generally states he can see better in the dusk than in bright light. At the commencement there is no defect in the field of vision, but simply a general dim- ness of vision. At a somewhat later stage examination of the field discovers no defect for a white object, yet if a small, pale- green object be employed, it will generally be ascertained that, at a region close to the point of fixation, the color is not recog- nized, but seems gray or white ; pink may seem blue and red may appear brown or black, while in other parts of the field the colors are recognized up to their normal boundaries. This is a central color-scotoma. 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 recognized. Hence the name Central Amblyopia. The scotoma is usually oval in shape, its long axis horizontal, and extends from the fixation-point toward the blind- spot of Mariotte (paracentric scotoma); but occasion- ally it is of much larger dimensions and sometimes surrounds the fixation point (pericentric scotoma). Even when the scotoma is very pronounced it remains " rela- tive," 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 (p. 372). 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. 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, while recovery of central vision cannot be ex- pected, the functions in the periphery of the field are usually maintained, and, consequently, these people, although incapaci- tated from reading, writing, and other fine work, do not lose their power of guiding themselves. Causes. — With but few exceptions, the subjects of this disease are men, probably because their habits and modes of life expose THE OPTIC NERVE. 397 them more than women to the influences which produce it. These are exposure to cold and wet; cold blasts on the body, especially the heated face (Samelsohn) ; but the most common cause is excess in the use of alcohol or of tobacco (toxic ambly- opia), or of both. I think the kind of alcoholic indulgence most likely to develop the disease is the frequent drinking of small doses of the stimulant. The individual who often gets thoroughly drunk, and between times drinks but little, is less liable to central amblyopia than he who, although never inca- pable of transacting his business, takes many half-glasses of whisky or brandy during the day. Dyspepsia and loss of appe- tite are constantly 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-to- bacco and cigars may cause it, but I have not known of a case due to cigarette-smoking. Excess in alcohol is usually combined with excessive smoking, but cases of pure alcohol- amblyopia certainly do occur — al- though some English 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 very much reduce their use of tobacco as well as of alcohol. Central amblyopia has also been observed in diabetes, and in poisoning from bisulphide of carbon,"^ so largely used in the manufacture of india-rubber. Retro-bulbar neuritis very occasionally attends disseminated sclerosis, with atroj^hy of the temporal side of the papilla ; but yet central scotoma is not always present. The Ophthalmoscopic Appearances in the beginning are either quite normal or there is slight hypersemia of the papilla and retinal vessels ; or, in addition, there may be slight indistinctness * Trans. Ophth. Soc, vol. v, p. 149. 398 DISEASES OF THE EYE. 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 grayish 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 observed by Samelsohn, Nettleship and Walter Edmunds, and UhthofF in the optic nerve consist of an interstitial neuritis at its axis, commencing so high up as the optic foramen, and leading to proliferation of connective- tissue and to secondary descending atrophy of a certain bundle of nerve fibres. These are doubtless the fibres which supply the region of the macula lutea. The changes are 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. The patients are generally ready to promise this, but they often do not act up to their intentions. When they do so, improvement rapidly takes place in most cases which are not too far gone, without any other treatment ; but the cure may be promoted by the use of iodide of potassium in large doses, Heurte- loup's artificial leech or dry cupping to the temples, hot foot- baths, and Turkish baths. Strychnine hypodermically (-^-^ grain daily) in the temple is often of use, and phosphorus and strych- nine may be given internally. Whatever remedy be used inter- nally, care should be taken that it does not produce or increase dyspepsia, and it may be necessary to restrict the internal medi- cine for a time, or altogether, to a stomachic tonic. Sleepless- ness should be combated with chloral and bromide of potassium. Treatment may have to be continued for some weeks before a cure can be noted. Optic Neuritis Associated with Persistent Dropping of Watery Fluid from the Nostril. — Nettleship * (one case), Priest- * Ophthal. Rev., 1883, p. 1. THE OPTIC NERVE. 399 ley Smith* (two cases), Leber f (one case), and Emrys Jones J (one case), have placed on record five well-observed cases of this remarkable disorder, and three others have been observed by Elliotson, Baxter, and Paget. These patients suffered from a persistent watery discharge from the nose (usually the left nos- tril), with more or less severe cerebral symptoms — violent head- ache, epileptic attacks, vomiting, stupidity, sleepiness, uncon- sciousness, delirium, weakness of the lower extremities, and a high degree of amblyopia, or even blindness, of both eyes, due to papillitis followed by atrophy. In Leber's case, moreover, there was loss of smell, and in Nettleship's case palpitation of the heart and prominence of the eyes. The fluid which ran from the nos- tril was, according to Leber, identical in its analysis with that of the cerebro-spinal fluid, while Nettleship and Priestley Smith found it to differ somewhat from that fluid. When, in P. Smith's case, it occasionally ceased to flow, the cerebral symptoms were brought on, or increased in violence. Leber's case was one of internal hydrocephalus, and he regards the fluid as coming from the third ventricle through a small opening in the ethmoid bone ; or the fluid possibly passed from the subdural space along the lymph spaces, which, according to Axel Key and Retzius, sur- round the olfactory nerves. But Priestley Smith and Nettleship considered the fluid as simply nasal, and due to the presence of small polypi, and did not try to account for its occurrence in connection with the cerebral and ocular symptoms. The first of these two views is probably the correct one. The Prognosis for vision is bad, while the cerebral affection threatens even the life of the patient. Treatment, which should be in conformity with the head symptoms, has not proved of use. Atrophy of the Optic Nerve. — This disease, may be secondary to some other optic nerve or retinal affection, or it may be a ^ Ophthal. Rev., 1883, p. 4. t A. V. Graefes Archiv, xxix, pt. 1, p. 271. X Meeting British Med. Assoc, Dublin, 1887. 400 DISEASES OF THE EYE. primary disease. The vision is seriously affected, and complete blindness is the usual result. With the ophthalmoscope the optic papilla is seen to have lost its delicate pink color and to have become white or grayish, while it is often cupped, and the vessels are apt to be diminished in calibre. Secondary Atrophy of the Optic Xerve may result : — 1. From Optic Xeuritis. — The ophthalmoscopic appearances consist in a white or grayish-white color of the papilla, with very diminished retinal vessels, and along both sides of the vessels, far into the retina, are seen white lines, which some- times even obscure the vessels, and which are due to hyper- trophy of their coats. The diminution in calibre of the vessel is a sign of ueuritic atrophy, but is not always present, and is moreover found with other forms of atrophy. Other signs of this form, also not constant, are : a certain opacity of the papilla, and that the lamina cribrosa is not generally visible, owing to development of connective tissue at the papilla. It is, evidently, not always possible to recognize any given case as of neuritic origin. Symptoms. — Central vision is lowered, and, as a rule, the field of vision becomes contracted, usually more at the nasal side. Subsequently, 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 color-vision is always much aflTected. The light-sense is aflfected, so that there is dimin- ished sensibility for diflferences of illumination ; w^hile, in cho- roido-retinal diseases, there is defect in the quantitative percep- tion of light, the minimum quantity being larger than normal.* 2. From Pressure. — This may be brought about by a tumor anywhere in the course of the nerve, by inflammatory exuda- tions, 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. * Bjerrum, F. Graefe's Archiv, xxx, pt. 2, p. 201. THE OPTIC NERVE. 401 3. From Embolism of the Central Artery of the Retina. — In these cases the contraction of the vessels is usually extreme. 4. From Syphilitic Retinitis, Retinitis Pigmentosa, and Cho- roido-retinitis. The vessels here are much attenuated, and the altered color of the optic disc is a dull yellow, rather than white or gray. Primary Optic Atrophy is often found associated with Disease of the Spinal Cord (Spinal Amaurosis), especially locomotor ataxy. Optic atrophy is often an early symptom in the latter disease ; but, again, it may not come on until the affection of the gait is well pronounced, while in other cases it is never present at all. 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. It is rare for a tabetic patient, in whom optic atrophy comes on in an early stage of his disease, to become ataxic ; and frequently, in these cases, when the blindness has advanced, the pains, too, become less severe. But, if amaurosis does not come on until the ataxy is well developed, no improve- ment in the latter is likely to be noted. Atrophy is, more rarely, found with insular sclerosis and lateral sclerosis of the spinal cord ; and 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 the papilla in spinal cases. The ophthalmoscope displays a papery-white or bluish-white papilla, which, in advanced stages, often becomes cupped. The retinal arteries are usually extremely reduced in calibre, and the veins, too, may be small ; but, again, the retinal vessels may differ but little or not at all from the normal. Symptoms. — Central vision is affected at an early stage in the disease, and eccentric contraction of the field usually appears at the same time. The contraction may be concentric or it may be more marked in one direction than another, and opinion is *Nettleship, Trans. Ophthal. Soc, 1883, p. 249, 34 402 DISEASES OF THE EYE. divided as to the direction commonly first involved. This concentric contraction advances gradually toward 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. Color-blindness is an almost constant symptom. As a rule, absolute blindness is brought about in the course of a year or two. Primary Optic Atrophy, of the progressive form just described, may occur, as a Purely Local Disease, without any other defect in the system. The prognosis for the sight in such cases is as bad as in spinal cases. Treatment. — In neuritic atrophy, so long as there are still signs of active inflammation, antiphlogistic measures— Heurte- loup's leech to the temple, hot foot-baths, rest of body and mind, dark room, iodide of potassium, and, especially, mercury inter- nally, when otherwise admissible — are to be adopted. At a later period hypodermic injections of strychnia (3-^ gr., increased gradually to 2V ^^ tt S^- ^^^^ ^ ^^j) ^^^ galvanism may be tried. In special 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 causes 2, 3, and 4 is to be directed to the primary disease. The Prognosis is very bad, for although every therapeutic measure may have been employed, amaurosis is the ultimate result, as a rule. Tumors of the Optic Nerve. — These are extremely rare. The chief forms are myxoma, glioma, and gliosarcoma or myxo- sarcoma. The symptoms which von Graefe held to be most characteristic of the presence of a tumor of the optic nerve are: Increasing protrusion of the eyeball forward and outward, with retention of its motion and without displacement of its centre of rotation. THE OPTIC NERVE. 403 The tumor is soft, so that the eyeball can, as it were, be pushed back into it, and there is no pain. The growth of these tumors is slow. It is sometimes possible to remove such a tumor, and yet to preserve the eyeball, by dislocating the latter during the operation. As a rule, it is necessary to enucleate the eyeball in order to reach the tumor, and if the growth have involved the surrounding orbital tissues these, too, must be taken away. Hyaline, or Colloid Outgrowths from the optic papilla, are occasionally met with. They present the appearance of bluish- gray, mulberry-like nodules. According to IwauofF, ^ they originate in the lamina vitrea of the choroid, at the margin of the papilla or within the area of the papilla, for the lamina vitrea is often prolonged into the papilla and takes part in the formation of the lamina cribrosa. But Gurwitschf disputes this view, and states that these growths spring from the coats of the vessels in the optic papilla. These outgrowths do not always cause a defect of sight, and rarely cause serious blindness. It is often found that a blow upon the eye has been received some time previously, and it is probable that such a trauma may have to do with the growth by rupturing the very brittle lamina vitrea. 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 in 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 may come on, usually only in one eye, and in these cases concussion of the nerve at its passage through the optic foramen, or an extravasation of blood in the sheath of the nerve, is probably the direct cause of the atrophy. Glycosuric Amblyopia. — In addition to the retinal affections ^ Klin. Monatshl. f. Augenhlk., vi, p. 425. t Centralbl. f. Augenhlk., Aug., 1891. 404 DISEASES OF THE EYE. dependent upon diabetes, we recognize the occasional occurrence in that disease of defects of vision, which are referred to dis- order 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 Amblyopia (see p. 397) or, in slighter cases, amblyopia without central scotoma. Occasionally, higher degrees of amblyopia with concentric contraction of the field of vision, and yet negative ophthalmoscopic appearances, are pres- ent. 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. It is probable (Leber) that these apparently diflferent kinds of blindness depend upon similar pathological processes and merely indicate degrees of the latter. In what these processes consist is still unknown, but the tendency to hemorrhages in the retina in diabetes makes it likely that hemorrhages in the optic nerve are sometimes the source of the amblyopia in question, while in the cases with central scotoma it is no doubt* due to retro-bulbar neuritis similar to that produced by tobacco, etc. Amblyopia is sometimes the only symptom of diabetes, and, consequently, as Leber points out, it is of the utmost importance to examine the urine for sugar in every case of amblyopia where the ophthalmoscopic 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 gone. Hirschberg f inclines to the view that diabetic amblyopia constitutes a serious symptom for the life of the patient. Hemorrhages from the Stomach, Bowels, or Uterus are capa- ble of giving rise to serious and incurable blindness. * Nettleship and Edmunds, Trans. Ophthal. Soc, vol. i, p. 124. t Ceatralbl. f. Augenheilk, 1886, p. 199. THE OPTIC NERVE. 405 Blindness during or immediately after a severe hemorrhage is probably due to insufficient blood-supply to the nerve-centres and retina, accompanying general exhaustion of the system. For such cases the prognosis is favorable. But there is another class of cases of very much more serious import. In these the defect of vision does not come on for from two to fourteen days after the hemorrhage, when the general system is recovering. Even comparatively slight hemorrhages, which caused no marked anaemia, are said to have been followed by blindness. The connection between the loss of blood and of sight in these cases is not yet clearly madie 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 hemorrhage is not made clearer. Papillitis has been several times noted with the ophthalmoscope in these cases, and this circumstance makes it probable that neuritis is the immediate cause of blindness — even in those cases which show no ophthalmoscopic sign of it — and hydrsemia may be presumed to be the poisonous 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 com- pletely amaurotic, while the vision of the other eye was quite normal, and one such case is sufficient to prove that the lesion is peripheral ; in fact, that it lies in each instance on the distal side of the optic chiasma. The field of vision is frequently con- tracted either concentrically or segmentally, and, even when central vision recovers, the field may remain contracted. The Ophthalmoscopic Ajypearances which are present immedi- ately on the occurrence of the blindness have not as yet been observed. A few weeks later they have been found to be 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 406 DISEASES OF THE EYE. papilla, and the arteries were extremely contracted, with slight distention of the veins ; or paleness of the papilla was present, but its margins were indistinct and the surrounding retina some- what swollen, while the retinal vessels were normal. Small hemorrhages have repeatedly been seen in the neighborhood 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, hopes may be entertained of marked improvement or of complete recovery. But Mooren has seen slight amblyopia pass into permanent amaurosis. Hemorrhages from the stomach are those which are followed by the most complete and permanent blindness, while uterine hemorrhages are more commonly followed by less serious degrees of blindness. The Treatment must consist of internal remedies calculated to correct the general ansemia, such as iron, beef tea and meat ex- tracts, wine, etc. Strychnine hypodermically, to stimulate the nerve, may be employed. CHAPTER XVII. AMBLYOPIA AND AMAUROSIS* DUE TO CEN- TRAL AND OTHER CAUSES. Hemianopsia (j];j.'.fTo^^ half; a, priv.; ax^', the eye). — This term implies a loss of sight in one-half of the field of vision, usually of each eye, consequent upon a lesion at the centre of vision, at the chiasma, or at some point in the course of the visual fibres between these two places. It is not used for cases in which one- half of the field is lost, owing to disease within the eye itself. Fig. 127. Fig. 128, Fig. 129. The line dividing the seeing from the blind half passes ver- tically down the centre of the field, as in Fig. 127. Sometimes this line lies a little to one side of the centre of the field, so as to admit of the latter being included in the seeing part, as in Fig. 128 ; and sometimes — although in other respects the divid- * These terms have been handed down to us from the old writers. Amblyopia {aupig^ blunt ; ^v-, the eye) is nowadays usually employed to signify defective vision due to disease or functional disturbance of the retina, optic nerve, or visual centre, but with healthy ophthalmoscopic appearances, or with signs only of optic atrophy. Amaurosis {aiuavpog, dark) means total loss of sight, with similar ophthalmoscopic appear- ances. Yet the use of these terms will be found sometimes to exceed the definitions here stated. 407 408 DISEASES OF THE EYE. ing line lies in the centre of the field — the fixation point is cir- cumvented by it, so as to leave that point free, as in Fig. 129 ; and, probably, this is the most common arrangement. This sub- ject will be further discussed on p. 410. Again, although rarely, the dividing line may have an oblique direction, as in Fig. 130. It is probable that such a field as Fig. 130 is due to some peculiar arrangement in the decussation of the nerve fibres in the individual case. Furthermore, cases occur which are prop- erly regarded as hemianopsia, and yet in which only a sector of one side of the field is wanting, as in Fig. 131. Figs. 127, 128, 129, and 130 would be called complete hemianopsia, while Fig. 1 31 would be termed incomplete, or partial, hemianopsia. Finally, if all three visual perceptions be lost, the hemianopsia is called Fig. 130. Fig. 131. absolute ; but if only one (color) or two (color and form) be wanting in the defective part of the field, it is termed relative 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 Fig. 132, in which the left side of the fields, from the patient's point of view, is blind, implying a loss of function in the right half of each retina. Temporal Hemianopsia is loss of vision in the outer side of each field, in consequence of loss of power in the median half of each retina (Fig. 133). It is by no means so common as the homonymous form. Superior or Inferior Hemianopsia, also called Altitudinal AMBLYOPIA AND AMAUROSIS. 409 Hemianopsia, iu which the upper or lower half of the field is blind, is very rare, and it is doubtful whether Kasal Hemian- opsia has really been observed, although it has been described. In the latter, the inner side of the field of one eye only is lost, owing to defective function of the temporary side of the retina. It will be convenient here to set forth the prevailing views Fig. 182. as to The Arrangement of the Cortical Visual Centres, their Relations to the Retina, and the Course of the Optic Fibres between these tivo points. Pathological anatomy leaves little doubt but that in man the visual centre is situated in the occipital lobe, rather than in the angular gyrus or elsewhere ; and the evidence goes Fig. 133. to show that the absolute optical centre chiefly occupies the cortex of the cuneus and of the superior occipital convolution, and also, especially in respect of the color-sense, the posterior part of the superior and inferior occipito-temporal convolutions. It is universally recognized that the nerve fibres from the homonymous half of each retina, e. r/., the temporal half of the 35 410 DISEASES OF THE EYE. right and the median half of the left retina, pass wholly through the corresponding optic tract — in this case the right tract — to the corresponding cortical centre for vision (Figs. 134 and 135, yellow). A case pu-blished by Hun,* in which the left lower quadrant in each field was blind, and where the autopsy showed a lesion (atrophy) strictly limited to the lower half of the right cuneus, renders it probable that there is in man a correlation between parts of the retina and of the occipital lobe, as Munk had already proved to be the case in dogs, and that the optic fibres from the right lower quadrant of each retina terminate in the adjacent part of the right superior occipito-temporal convolution, the left halves of the retina and left optic centres being, of course, similarly correlated. If this view be correct, as seems probable, it is evident that altitudinal hemianopsia can hardly occur as the result of a central lesion, as nothing short of disease confined to the lower half of each cuneus would pro- duce it. It is also probable that the centres for the three visual perceptions of light, form, and color are distinct from each other, and that they are arranged, as it were, in layers, one over the other. It is now generally conceded that the macula lutea is specially represented in. the cortical centre ; but there are at least two very distinct views as to the arrangement of these macular centres and as to the course of the macular fibres. These different views have been called into existence by the desire, to explain the fact that in hemianopsia the line of demarcation sometimes passes through the fixation point in the field, and sometimes leaves it in the seeing half It seems to me that neither of these theories is satisfactory, and I regret that I cannot oflfer one that is so. According to one theory, illustrated by Fig. 134, the whole of the macular region — and in some instances even more than this * American Journal of the Medical Sciences^ January, 1887. FIGA. L F R F. rmcc. EXPLANATION OF COLORED FIGURE (A) ISL Fig (A) 134 — Diagram of Cour??e of Optic Fibres wiih the centres for the Three Visual Perception?, and Relations to Fields of Vision to illus- trate one theory of the Macular Supply ; according to which, each macula lutea is innervated from each hemisphere. R.F., Right field of vision ; L.F., Left field of vision ; E.E., Right eye (retina) , L. E , Lef: eye (retina) ; ML and Ml , Macula lutea ; 0. X. and O.N., Optic nerves; Ch., Chiasma ; Tr. and Tr., Optic tracts; B.C C. and L.C.C . Right and left cortical centres ; M and M., Macular fibres; P. and P., Peripheral fibres; L f, c. and ?, /, c, Centres for the three visual perceptions — light (/), form (/), and color (c) — arranged in layers. 1. Lesion of right cortical centre = lefc homonymous hemianopsia, with the line of demarcation passing round the fixation point, owing to overlapping of supply to the macula from the opposite hemisphere. 2. Lesion of the right tract ^ lefc homonymous hemianopsia, with the line of demarcation passing round the fixation point. 3 Lesion of the chiasma = temporal hemianopsia, with the line of demarcation passing round the fixation point. 4. Lesion of the fisciculus lateralis only to the right eye, causing na?al hemianopsia in the right field. EXPLANATION OF COLORED FIGURE (B) 135, Fig. (B) 135. — Diagram of Cour.se of Optic Fibres, wiih the centres for the Three Visual Perceptions, and Relations to Fields of Vision, to illustrate the second theory of the Macular Supply ; according to which the macula is supplied on the same plan as the rest of the retina, i. e., each side of it from the corresponding side of the brain. R.F., Right field of vision; L.F., Left field of vision ; R.E., Right eye (retina) ; L E., Lefc eye (retina) : Ml. and ML, Macula lutea; O.N. and O.N., Optic Nerves; Ch., Chiasma; Tr. and Tr., Optic tracts; R.C.C. and L.C C, Right, and Itfc cortical centres ; M. and M., Macular fibres; P. and P., Peripheral fibres; Z, /, c, and Z, /, c, Centres for the three visual perceptions— light (Z), form (/), and color (c),— arranged in layers. 1. Lesion of right cortical centre = left homonymous hemianopsia, the line of demarcation passing round the left side of the fixation point in cases of embolism and thrombosis, but through the fixation point in cases of hemorrhage (see p 411). 2. Lesion of the right optic tract = left hemianopsia, the line of demarcation passing through the fixation point. 3. Lesion of the chiasma = bitemporal hemianopsia, the line of demarcation passing through the fixation point. 4. Lesion involving fasciculus lateralis only to right eye, causing nasal hemianopsia in the right field. Diagrams 134 and 135 illustrate the fact that, as regards its relation to the optic tracts, the field of each eye is divided unequally, and not in halves, e. g., the right tract governs about one-third of the field of the right eye, while the other two-thirds is governed by the left optic tract. FIG B. L.F. R.¥. L.C.C.|^ f IR.C.C. c AMBLYOPIA AND AMAUROSIS. 411 — of each retina being innervated from each hemisphere, there is an overlapping, as it is called, of nervous supply to these retinal regions. Consequently, if there be a lesion at the centre for vision in one occipital lobe, the centre for vision in the other occipital lobe being sound, the functions of the whole of each macula — or even of more than this, of the defective side of each retina — will be preserved. Cases where, occasionally, in cortical lesions, the line of demarcation in the field does go through the fixation point, would be accounted for, under this theory, by an individual variation in the supply of the maculae, which, in these instances, would be similar to that of the remainder of the retinae. According to the other theory, illustrated by Fig. 135, the macular region of the retina is invariably supplied on the same plan as the rest of the retina, i. e., each side of it from the corresponding side of the brain. In order, then, to explain why it is that in some cortical lesions the line of demarcation passes through the fixation point in the field, while in others it deviates toward the blind side, the supporters of this view state that the cortical centre for the macular region is more richly supplied with blood-vessels than the rest of the visual centre, as is the macula lutea itself in relation to the rest of the retina. Hence, when the lesion is an embolism, or thrombosis, of the vessels supplying that part of the brain, this special region, by reason of abundant anastomoses, preserves its functions, and then fields as in Fig. 132 are produced. But, if the lesion be a hemorrhage, the macular region of the cortex would be apt to be involved in the lesion with the rest of the visual centre, and loss of function in the corresponding half of the macula lutea, with the line of demarcation passing through the fixation point, results. But any such theory, to be satisfactory, must be capable of explaining the phenomenon in question, not only when the lesion is in the cortex, but also where the hemianopsia is caused by a lesion in the tract or chiasma. Yet an examina- tion of Fig. 134 will show that, according to the theory it 412 DISEASES OF THE EYE. represeiit8, in lesions of the tract (2; or of the chiasma (3) the fixation point would always be spared ; and, according to the theory illustrated by Fig. 135, a lesion either at the tract or at the chiasma would always cause the dividing line to pass through the fixation point. It happens, however, that with lesions at either of these situations, the dividing line sometimes passes through the fixation point and sometimes to one side of it. Consequently, I do not think we have yet solved the problem of the nervous supply of the macula lutea. The Localization of the Lesion in Cases of hemianopsia is a subject of interest, and, in view of the advances made within recent years in cerebral surgery, it is of great practical im- portance. Temporal Hemianopsia (Fig. 133) is in all cases due to a lesion so situated at the chiasma as to involve the fasciculus cruciatus from each eye. In very many cases of temporal hemianopsia the other side of the field is somewhat involved, owing to the lesion implicating some of the fibres of the neigh- boring fasciculi laterales. In Altitudinal Hemianopsia the lesion must also be at the chiasma, encroaching on it from above or below. 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 of the affected eye. The occurrence of binocular nasal hemianopsia is evidently almost impossible, implying, as it does, symmetrical lesion of the fasciculus lateralis of each tract. In Homonymous Hemianopsia — the commonest form of the symptom — localization of the lesion is a more difficult matter than in any of the other forms ; for here the disease cannot be situated at the chiasma, but may be in the optic tract, or in the visual centre, or anywhere in the lengthened course of the fibres which connect these two parts. Can we distinguish a complete and absolute hemianopsia, due to a lesion confined to the occipital lobe, from a similar defect in the field, due to a lesion in the optic radiations, internal capsule, AMBLYOPIA AND AMAUROSIS. 413 pulvinar, or optic tract? We may conclude that the hemianop- sia depends upon an occipital lesion if it be unaccompanied by hemiplegia, motor aphasia, or paralysis of cerebral nerves, as di- rect symptoms — as might occur with a lesion in the posterior limb of the internal capsule on the left side (vide infra) ; but, be it remembered, that one and all of these are liable to accom- pany lesions of the occipital lobe as distant* symptoms. 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 incomplete, inasmuch as the homonymous quadrant only of each field may be wanting. The explanation of this has been given when speaking (p. 410) of the correlation of the visual cortical centres to parts of the retina. Cortical hemianopsia may be a distant symptom. Gowers has observed that, at the onset of many attacks of cerebral hemorrhage, hemianopsia is present as a distant symptom of very fleeting character, so fleeting, indeed, that it does not complicate attempts at localization. Except under this condition, distant hemianopsia seems to be rare, a fact which enhances the localiz- ing value of the symptom. So much for absolute hemianopsia. But the lesion may be such as to destroy only the color centre, without reaching those for form and light. Eight cases of hemiachromatopsia are on record. *I suggest the term "distant symptom" 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 pressure. In short, we do not yet 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 — although perhaps not quite gram- matically—without committing us to any theory. The corresponding German term is " Fernwirkung." 414 J)ISEASi:S OF THE EYE. Again, the form-sense may be lost in the half field along with the color-sense, while only the light-sense is retained. Such cases are hardly less rare than the loss of the color-sense alone. Furthermore, cases of hemianopsia are on record in which, in part of the defect, both the color and form-senses were absent, but the light-sense present, while in the remainder of the defect all three visual perceptions were lost. Hemianopsia from a lesion in the optic radiations will often be indistinguishable from the same symptom due to a cortical lesion. The defect may be incomplete, as the lesion may impli- cate only some of the radiating fibres ; or it may be complete if they are all involved. Pronounced distant symptoms, such as hemiplegia, hemiansesthesia, ptosis, and so on, are more apt to be caused by a lesion here than in the cortex. A lesion in the posterior third of the posterior limb of the internal capsule — the sensory crossway — is likely to produce complete hemianopsia, because the nerve fibres are here col- lected together in a small space. Hemian^esthesia will be pres- ent as an accompanying direct symptom ; and also, sometimes, loss of the other special senses on the opposite side from the lesion ; and, should the disease extend forward to the anterior part of the posterior limb, hemiplegia will be added as a direct symptom. Moreover, if the lesion be on the left side, motor aphasia may be present, by reason of the proximity of the path for speech on its way to the cerebral peduncle. I have already spoken of the combination of cortical hemianopsia with aphasia. There are a few cases on record of hemianopsia caused by a lesion in the pulvinar. The symptoms in such cases strongly simulate those present in many cases of cortical hemianopsia, so that a diflferential localization as regards these two positions may be impossible. The hemianopsia will be absolute, and probably complete ; but lesions just in this situation seem to be very rare. In hemianopsia due to a lesion of the optic tract the defect in the field is usually comj)lete. The characteristic sign which enables us to localize a lesion in AMBLYOPIA AND AMAUROSIS. 415 the optic tract from one elsewhere causing hemianopsia is the hemiopic pupil. Illumination of the amaurotic half of the retina alone produces no contraction of the pupils, or, at most — owing to dispersion of the light within the eye and consequent excitation of the seeing part of the retina — a very sluggish one ; because the lesion is on the distal side of the corpora quadri- gemina, and, consequently, the impulse cannot reach Meynert's fibres to be conducted to the centre for the third nerve (see pp. 273 and 283). It must be stated that some observers deny the occurrence of the hemiopic pupil. But, on the other hand, many observers have obtained the symptom. A great obstacle in observing it lies in the difficulty of concentrating the light on the blind side of the retina, without allowing it to fall on the good side. It is true that if the pupil-fibres in the optic nerve run as Bechterew thinks they do (p. 274), the hemiopic pupil could not occur. Lesions of the optic tract are, of course, apt to implicate the crus cerebri, but do not necessarily do so ; and then we would have hemiplegia of the opposite side of the body associated with the hemianopsia. Leber has pointed out that atrophy of the optic nerve is likely to make its appearance, and at an early stage of the case, in lesions of the tract. The Forms of Diseased Process which are found in cases of hemianopsia are : Hemorrhage, softening, tumor, abscess, occa- sionally chronic inflammatory processes, and, sometimes — with the lesion in the occipital lobe — trauma. The Ophthalmoscopic Appearances, as a rule, are normal. But, when the lesion is of such a nature as to produce it, optic neuritis may be present. With temporal hemianopsia optic atrophy is not uncommon. The Prognosis for recovery of vision in the defective half of the field depends, of course, upon the nature of the lesion ; but recovery does not usually take place, especially in the most com- mon class of cases — those, namely, which are due to cerebral apoplexy. Alexia (a,priv.; ?^i^i?, speech), or Word-Blindness, is the term 416 DISEASES OF THE EYE. given by Kussraaul to an inability to understand written or printed characters, although they, and other small objects, can be distinctly seen. The patient can express his ideas in writing, or write from dictation, yet cannot understand what he has just written. He does understand the meaning of spoken words and the use of all objects around him. The condition has been occa- sionally complicated with hemianopsia.* In those cases where an autopsy was obtained, the lesion was found in the inferior parietal lobule of the left hemisphere, or extending from it into the temporal region or into the angular gyrus and occipital lobule.t Dyslexia. — This symptom was first described by Berlin. j In a wide sense, it belongs to the aphasic group. It consists in a want of power on the patient's part to read more 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 dis- like 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 backward and turned 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 head- ache, giddiness, aphasia, hemianopsia, paralysis of the tongue, hemiansesthesia, hemiplegia, twitching of the facial muscles, etc. ^ Charcot in Gaz. des. Hop., Mai, 1883. t Ferrier, "Functions of the Brain," 2d ed., p. 454; Allen Starr, Brain, July, 1889, p. 82. X Archiv fur Psychiatrie und N erven Krankheiten, vol. xv, p. 276, and in his Monograph, " Eine besondere Art. der Wortblindheit (Dyslexic)" (Wiesbaden, 1887). AMBLYOPIA A^'D AMAUKOiSlS. 417 Seven or eight cases are on record, and all have ended fatally. The lesion was situated, in all but one of those cases where an autopsy was obtained, in the neighborhood of Broca's lobe. In one case the left hemisphere was normal, while the right hemi- sphere was extensively diseased. Soul-Blindness, Psychical-Blindness, or Mind-Blindness is a symptom first observed by Munk "^ in his experiments upon animals. It consists in the loss of power of recognizing objects, while the power of seeing them continues. A whip is seen by the animal, but inspires no terror; attempting 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. Ferrier seems t dis- inclined to accept Munk's experiments. The symptom, however, has been observed in man under certain diseased states, e. g., after apoplectic seizures and in progressive paralysis. Some authors localize the centre for visual memory in the angular gyrus, while others take it for the whole of the occipital lobe, except the cuneus and its neighborhood. Congenital Amblyopia. — This condition is not very uncommon. Ophthalmologists, in the course of their practice, come across people in whom the vision of both eyes 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 a congenital amblyopia in one eye. As a rule, the field of vision and the color- vision are normal, but cases are seen in which there is contraction of the field with defective color-sight. The Ophthalmoscopic Appearances are normal. Reflex Amblyopia is said to have been observed, and chiefly in connection with irritation of the fifth pair, especially its dental branches; but I have not seen these cases and I am * " Zur Physiologie der Grosshirnrinde," Archiv f. Anat. und Phys- iol.,, V and vi, pp. 162 and 547. t "The Functions of the Brain," 2d ed., p. 298. 418 DISEASES OF THE EYE. rather skeptical as to their occurrence. 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 extreme degree, vision being reduced even to the merest perception of light. More generally recognized than amblyopia, as the result of toothache, are: Hypersesthesia of the retina, photophobia, sub- jective 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 supraorbital nerve were looked on as the cause of amblyopia or of amaurosis, but it is by no means certain that an ophthalmoscopic examina- tion would not have afforded another explanation in many of these cases. Yet, even nowadays, many hold that wounds of the supraorbital 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. Sympathetic Irritation (p. 261) is to be included under this heading. It is seen in the sound eye in some cases of cyclitis, and must not be confounded with sympathetic ophthalmitis, which comes about in quite a difl^erent way. Its symptoms are: Diminution of the amplitude of accommodation, asthenopia, hy- persesthesia of the retina, lachrymation, and subjective appear- ances of light. Removal of the first eye, if otherwise indicated, always re- lieves sympathetic irritation ; but where this is not admissible the dark room, atropine, dry cupping at the temple, with bro- mide of potassium internally, may be employed. The Ophthalmoscopic Appearances in reflex amblyopia are nor- mal. Hysterical Amblyopia. — In hysterical individuals amblyopia is sometimes seen, either as the only symptom or in combination AMBLYOPIA AND AMAUROSIS. 419 with Others. It takes various forms, e. g., complete blindness, even to loss of perception of light; defective central vision, with concentric contraction of the field, or with segmental peripheral defects in the latter, or as central scotoma. The color vision is often affected. The Ophthalmoscopic Appearances are normal and the Prog- nosis good. Treatment must be directed to the general system. Nyctalopia (Xight-Blindness). — This is a well-recognized symptom of the disease known as Retinitis Pigmentosa (p. 373). I have recorded"^ an instance of congenital night-blindness in five members of a family of ten children, without ophthalmo- scopic signs, and Richter, quoted by Lawrence, observed a simi- lar instance. But the condition of which I have here to speak is Acute, or Idiopathic, Night-Blindness. The patients can see well in good daylight, but of 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, which are quite plain to other people, and, in a still worse light, they fail even to recognize 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 are often present in acute nyctalopia (p. 115). Some observers have found mi- crococci and bacilli in the conjunctiva in these cases, and have regarded these organisms as the cause of the conjunctival affec- tion. It seems now more probable that they are merely second- ary to the xerosis. The connection between nyctalopia and xerosis conjunctiva- remains to be explained, but it is likely that they are both re- sults of the one cause. Acute nyctalopia is often the result of long continued * Irish Hospital Gazette, March 15, 181 420 DISEASES OF THE EYE. dazzling by very bright sunlight or of lengthened exposure to bright firelight (e. (jr., in foundries), and it is probable that in many, if not in most, instances of this affection defective nutri- tion of the system plays the chief role in rendering the patients liable to it. Thus, in scorbutus, acute nyctalopia has been fre- quently seen when the patients have been exposed to strong glares of sunlight. Treatment consists in protection from light, — in short, in com- plete darkness for a time, — and then gradual return to ord'nary daylight ; while the system is to be strengthened by careful die- tary and suitable tonic medicines. Uraemic Amblyopia. — This is most commonly seen in connec- tion with the nephritis of pregnancy and scarlatina, but may occur in any case of ur?emic poisoning. The blindness is usu- ally absolute, and may come on suddenly, or with a short pre- vious stage of dimness of vision. The Ophthalmosco2:>ic Appearances are negative. Treatment can only be directed to the general condition. The Pror/nosis for vision is good, as it always recovers if the patient's life be spared. Snow-Blindness. — Exposure of the unprotected eyes for a length of time to the glare from an extensive surface of snow produces dimness of sight, which may amount to almost com- plete blindness, but which usually passes off again as soon as regions free of snow are reached. One or two instances have been recorded in which the affection continued some days after the exposure and then underwent recovery. Pretended Amaurosis. — Malingerers rarely pretend total blindness of both eyes, and such cases can often only be detected by constant observation of their actions. Presence of pupillary reflex is no proof that the patient sees, for this would be quite compatible with a cortical lesion causing total loss of sight (p. 284). The crossed diplopia test {vide infra) may be employed in these cases, as, if both eyes see, the one with the prism will rotate inward for the sake of single vision, while if both eyes AMBLYOriA AND AMAUROSIS. 4"21 be blinr , of course no such motion will take place. Again, if the mal ngerer's own hand be placed in various positions, and he be asked to look at it, he will, in all probability, look in some other direction ; whereas, a truly blind man usually makes a fair attempt at directing his eyes toward his own hand. Pretended monocular amaurosis can generally be detected by The Diplopia Test. If the malingerer be made to look, with both eyes open, at a lighted candle placed some feet off, while a prism with its base downward 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 outward before the pretended blind eye ; when, if he sees, it will make a rotation inward for the sake of single vision, an effort which a blind eye would not make. Alfred Graefe'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°) is held base down before the good eye, so that its edge may pass horizontally across the centre of the pupil. Monocular 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 downward by the prism. The double images stand over each other. If now the hand which excludes the pretended blind eye be rap- idly removed, while at the same moment the prism is moved upward, so that the entire pupil is covered by it, a malingerer will still see double images standing one over the other, for now the diplopia must be binocular. Harlan's Test"^ consists in placing a trial frame on the patient's nose with a very high -j- lens — say -{- 14 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, which, of course, Trans. Amer. Ophthal. Soc, vol. iii, p. 400. 422 DISEASES OF THE EYE. would not materially iuterfere with 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 will then be unable to read the test-types. Snellen's Colored 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 with the good eye. But if a green glass be held be- fore the good eye the rays from the red letters will be excluded and he will 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 admittedly good eye a green glass, and if he now still see the red letters it must be that he does so with the so-called blind eye. It is well to have this variety of tests in order that they may be used to corroborate each other. Erythropsia (Jf>o0f>6i, red — Red Vision). A large number of cases of this remarkable affection are on record ; indeed, it will have come under the notice of nearly every ophthalmic surgeon of any experience. Two-thirds of the cases have been subjects of successful cataract operations, whilst the remainder have pos- sessed normal eyes. In some cases the red vision remains only a few minutes and does not again return ; whilst in others it ap- pears every day for a short time, for weeks 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, in one case, the interval was two years. During the attacks the patients see all objects of a deep red color, and occasionally of a purple or violet hue. In no instance is the acuteness of vision affected, either during or after the attacks. A satisfactory explanation for the affection has not yet been offered. It seems probable that it is due to over-excication of the visual nervous apparatus — some believe of the visual centre, AMBLYOPIA ANT) AMAUROSIS. 428 Others of the retina — set agoing by exposure of the retiua to strong light, along with other favoring circumstances, especially- general over-excitement of the body or mind. More than this cannot at present be said. Why aphakic eyes should be so much more liable to erythropsia than eyes which possess their crystal- line lenses is an enigma. Treatment seems to have but little effect. Protection of the eyes from light has not been of use. Bromide of potassium in- ternally seems to have done some good in those cases where it was tried. CHAPTER XVIII. THE MOTIONS OF THE EYEBALLS AND THEIR DERANGEMENTS. The eyeball moves round a point on its autero-posterior axis situated (in the emmetropic eye) 14 millimetres behind the cor- nea and 10 millimetres in front of the posterior surface of the sclerotic. Its motions are effected by means of the six orbital muscles, arranged in three pairs, each pair consisting of two an- tagonistic muscles ; thus, the rectus internus and rectus externus are antagonistic, the former rotating the eye inward and the latter rotating it outward. The two remaining pairs are the recti superior and inferior, and the obliqui superior and inferior. The Primary Position of the Eyeball is that one in w^hich, the head being held erect, the gaze is directed straight forward in the horizontal plane. This is the starting-point from which the actions of the muscles are considered. The Rectus Externus and Pectus Internus, lying from their origin to their insertion in a plane which corresponds with that of the horizontal plane of the eyeball, move the latter on its perpendicular axis directly inward and outward, and have no other action. The plane of The Pectus Suj^erior and Pectus Inferior does not quite correspond with the vertical plane of the eyeball, and con- sequently the axis on which they rotate the globe is not its hori- zontal axis, but one which, passing from within and before, backward and outward, forms with the antero-posterior axis an angle of 70° (Fig. 137). While, then, their action is mainly to rotate the eyeball upward and downward, these muscles rotate 424 THE ORBITAL MUSCLES. 425 Fig. 1 it also somewhat inward. Moreover, the superior rectus giving to the vertical meridian of the cor- nea an inward inclination or inward wheel-motion^ of the eye {vide infra), while the inferior rectus gives this meridian an outward in- clination or outward wheel-motion of the eye, the power of these mus- cles 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 horizontal axis of the globe ; and their influence over the wheel- motion is greatest when the eye is turned in, for then their axis coin- cides most closely with the antero-posterior axis of the globe. The plane of The Oblique Muscles of the eyeball also approaches the vertical plane of the eyeball, the axis upon which they rotate the lat- ter passing from within and behind, forward and outward, and mak- ing with the antero-posterior axis an angle of 35° (Fig. 138). The principal action, accordingly, of the oblique muscles is to incline the vertical meridian of the cornea ; the sup. oblique inclines it inward (wheel-motion inward), the inf. ob- lique inclines it outward (wheel- motion outward). In addition to ^ this action the oblique muscles, "^^1%^ '/ respectively, rotate the eyeball * In speaking of the inclination of the vertical meridian of the cornea, it is the upper extremity of this meridian which is meant. 36 426 DISKASES OF THK EYE. downward and outward (sup. oblique), and upward and outward (inf. oblique). It is evident that the power of these muscles over the upward and downward motions of the eyeball is great- est, if the eye be turned in, and that their power over the wheel-motion is greatest when the eye is turned out. To sum up, then, the superior oblique and rectus produce wheel-motion inward, while the inferior oblique and rectus pro- duce w^heel-motion outward. The action of the obliques on the wheel-motion is greatest when the eye is rotated outward, and of the recti when the eye is rotated inward. In considering the motions of the eyeballs, we have to think of the motions of one eyeball as associated with those of its fel- low ; e. g., the action of the internal rectus of the left eye is asso- ciated with the action of the external rectus of the right eye, in rotation of both eyeballs to the right. The vertical meridian of the eyes becomes inclined to the right or left in different positions of the globe, as has been experiment- ally proved by Donders. 1. In the primary position, as also when the eyes are turned di- rectly inward, outward, ^^^- ^'^^- upward, or downward, the vertical meridians (a, h, Figs. 138-143) maintain their vertical direction (Fig. 139). 2. When the eyes are turned to the left, and iipivard, the vertical meridian of each eye is inclined at the same angle to the left (Fig. 140). Wheel-motion to the left. 3. When the eyes are turned to the left, and downward, the vertical meridian of each eye is inclined to the right at the same angle (Fig. 141). Wheel-motion to the right. 4. When the eyes are turned to the rirjht, and upward, the vertical meridian of each eye is inclined at the same angle to the right. Wheel-motion to the right (Fig. 142). THE ORBITAL MUSCLES. 427 5. When the eyes are turned to the right, and downward^ the vertical meridian of each eye is inclined at the same angle to the left. Wheel-motion to the left (Fig. 143). We shall now con- sider which muscles are called into action when an individual requires to place his eye in the several principal Fig in positions. 1. In the Primary Position all the muscles are at rest. 2. Motion of the eye- ball directly outward is effected by the external " rectus alone, and motion directly inward by the internal rectus alone. 3. Motion of the eye- ball directly upward and directly downward is effected chiefly by aid of the sup. and inf. recti. But these mus- cles, acting alone, rotate the eyeball slightly in- ward, and give a certain inclination to the vertical meridian, which, in this position, ^^^- 1^^- should be upright. Con- sequently, in rotation of the globe directly upward, the inf. ob- lique, which rotates the eye slightly outward (as well as upward), and inclines the vertical meridian outward, must be associated with Fig. 142. 428 DISEASES OF THE EYE. the sup. rectus in order to counteract in these particulars the tendency of its action. In rotation of the eyeball directly downward, the inf rectus must be associated with the sup. oblique, which acts antagonistically to this rectus in respect of rotation inward, and of outward wheel-motion. 4. Kotation upward and outivard is chiefly effected by aid of the rectus superior and rectus externus. But the latter muscle has no influence over the wheel-motion, while the former pro- duces wheel-motion inward. Yet, the inclination of the vertical meridian is outward in this position, and, therefore, a third muscle, which will supply this inclination in a high degree, is required — namely, the inferior oblique, whose power over the wheel-motion of the eyeball is greatest when the latter is in this position. 5. Rotation doivnward and outivard is chiefly effected by the rectus inf and rectus ext. Inasmuch, however, as the former inclines the vertical meridian outward, while the latter has no influence over it at all, a third force is required, which will bring about the required inward wheel-motion — namely, the sup. oblique, whose influence in this respect is most powerful when the eye is in this position. 6. Rotation upward and inward is chiefly brought about by the rectus superior and rectus internus. But the effect of the former upon the inward wheel-motion of the eye would be so great as to interfere with parallelism of the vertical meridians of the two eyes, that of the other eye not being inclined outward in a corresponding degree. A third force, therefore, is required, which will, to a certain extent, counteract the influence of the sup. rectus in this respect, and this is the inf. oblique, which, in this position of the eyeball, has but slight power over its wheel- motion. 7. Rotation downward and inward is chiefly the result of con- traction of the rectus inf and rectus int. The power of the former over the outward inclination of the vertical meridian would, in a similar way, be too great, and must be similarly corrected by the action of the superior oblique. the orbital muscles. 429 Paralyses of the 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 itself a disease. It may be due to lesions in several different situations, namely : 1. Lesions situated in the orbit. 2. Peripheral, also called basic, lesions — lesions situated at the sphenoidal fissure, and those at the base of the skull, between that point and the pons. 3. Pon- tine or nuclear lesions — lesions in the substance of the pons and those which only attack the nuclei of the nerves in the aqueduct of Sylvius and floor of the fourth ventricle. 4. Cerebral lesions — lesions above the nuclei in the internal capsule, corona radiata, or cortex. These four classes differ considerably in their clinical aspect, in their pathological causes, and in their significance for the well-being of the patient. The first class — loss of power due to orbital lesions — will be referred to in the chapter on Diseases of the Orbit. The second class — those due to peripheral lesions — provides by far the largest number of cases of paralyses of the orbital muscles. Let us now consider the — General Symptoms of this class. They include symptoms to be found in each of the other classes. 1. Diplopia. The affected eye being deviated from its correct position and being more or less incapable of associated motions with the other eye, the image of the object looked at is not formed on identical spots of the retina in each eye, and hence the object seems doubled. 2. In- distinct vision. If the paralysis be but slight, actual diplopia may not be present, but the double images overlapping each other will cause dimness or confusion of sight. 3. Giddiness, due partly to the diplopia and partly to faulty projection of the object. 4. Some patients turn the head toward the side of the paralyzed muscle in order to diminish or eliminate the diplopia ; e. ^ , if the left ext. rectus were paralyzed the head would be turned toward the left; if it were the left int. rectus the head would be turned toward the right. By this manoeuvre the loss 430 DISEASES OF THE EYE. of the action of the affected muscles is less felt for objects which lie straight in the patient's path while he walks about, as it in- volves a rotation of the eye toward the side of the healthy antagonist, in which region of the binocular field the diplopia is reduced to the minimum. Some patients close one eye to procure single vision. 5. 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, excep- tions 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 toward the side of the affected muscle, e. g., toward the left if the left external rectus be paralyzed, toward the right if the left internal rectus be paralyzed. 2. The secondary deviation (i. e., the deviation of the sound eye while the affected eye fixes) is greater than the primary deviation {i. e., the deviation of the affected eye while the sound eye fixes). Because the muscle in the sound eye, which is associated in its action with the paralyzed 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 ex- cite its action, its associate will be over-excited. Let us suppose the left external rectus to be paralyzed, 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-hand side ; we may notice on removing the shading hand that the right eye has been rotated inward 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 (seems to lie) in the direc- tion of the paralyzed muscle; e.g., if the left ext. rect. be paralyzed the image of that eye will be formed to the inside (at /?, Fig. 144) of the macula lutea (?n'), and will, therefore, seem to lie to the left (at h') of the image belonging to the right eye. THE ORBITAL MUSCLES. 431 Where the image of the affected eye lies to the corresponding side, as in this instance, the diplopia is termed homonymous, and such double vision always indicates convergence of the visual lines. But, suppose the internal rectus of the left eye to be para- lyzed, the image on the retina of that eye falls then to the outside of its macula lutea, and must, therefore, be projected to the right of the true position of the object ; this is crossed diplopia, and attends divergence of the visual lines. Fig. 144. Paralysis of the External Rectus of the Left Eye.— If this be complete, or considerable, it is easy of diagnosis, as marked loss of power of motion of the eyeball outward is present, and the patient complains of double vision. He keeps his head turned to the left, in order to diminish the influence of the paralyzed muscle as much as possible. If, however, the paralysis be but slight, the patient may not complain decidedly of diplopia, but only of indistinctness or confusion of sight, especially when he looks toward the left. 432 DISEASES OF THE EYE. 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, at 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 on the same level, the red candle to the left, the white to the right, i. e., homonymous diplopia = convergence. 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, h. In order to determine this point, the candle must be carried from side to side, and the increasing 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 while his head remains fixed, the images come still closer together, or only one candle is seen. But if the candle be carried to the patient's left-hand side, the images go further apart, their relative positions being main- tained. We now know that it is the left external rectus which is affected, because toward 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, however, the candle be held to the left and raised aloft, the image belonging to the left eye w^ill seem to lean away from that of the right eye (Fig. 145). The reason of this is, that, owing to the paralysis of the external rectus, the left eye cannot look upward and outward as it should, but merely looks * Maddox's Rod Test, described further on, is very suitable here, and in the investigation of other forms of ocular palsy. THE ORBITAL MUSCLES. 433 upward. The vertical meridian therefore 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 therefore 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 derangement of the vertical meridian takes place in the position below and to the outside, d. If the patient be told to direct his gaze specially toward the red candle the dis- tance between the two candles will be much greater than if he direct his gaze toward the white candle. This is explained by General Principle No. 2, p. 430. If the patient's good eye be closed, and an object (surgeon's finger) be held up within his reach, but toward his left-hand side, and he be requested to aim rapidly at it with his fore-finger, he will aim to the left of it. The nervous impulse sent to his left external rectus, to enable him to turn the eye toward the object, is of such intensity as to lead him to fancy that the object lies much further to the left than it does (incorrect projection of the field of view) ; for we, to a great extent, estimate the distance of objects from each other by the amount of nervous impulse sup- plied to our orbital muscles in motions of the eyeball. A prism held horizontally before the affected eye, with its base outward, brings the double images closer together ; or, if the correct prism be selected, the images will be 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 downward and inward, motion in this direc- tion being that over which the superior oblique has most influ- ence. Still, absolute defect of motion is sometimes difficult to detect, even in complete paralysis of this muscle, owing to vica- rious action of the inferior rectus and internal rectus. Careful 434 DISEASES OF THE EYE. examination of the secondary deviation will often be successful as to this point, but it is the examination of the double images upon which we must chiefly depend for the diagnosis. 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 downward, the latter, for want of the action of this muscle, now stands higher than its fellow (right eye), and, consequently, the image will not fall on its macula lutea (as it does in the right eye), but above it, and will therefore be projected below the image of the right eye. The position, downward and inward, of the eyeballs is that in which the greatest demand is made upon the superior oblique for rotation of the eye downward : therefore, it is in this position its want for this purpose is most felt, and when the candle is held in this position the vertical distance between the double images is greatest, b. The superior oblique assists also in rotation of the eye outward : therefore, loss of its power must commit the eyeball, to a certain extent, to the power of the muscles which move it inward, 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 inward : there- fore, in rotation directly downward, 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 in- clination to the patient's right hand. d. The power of the supe- rior oblique to incline the vertical meridian inward is greatest when the eye is turned downward and outward ; consequently, in this respect its paralysis will be most felt 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 infe- THE ORBITAL MUSCLES. 435 rior rectus), and for which a good explanation does not exist, is, that the image belonging to the affected eye seems to stand nearer the patient than that of the sound eye. To sum up, then (vide Fig. 146) : below the horizontal plane there is ^^* homonymous diplopia, while the Q image (A) of the affected eye stands on a lower level, is inclined toward the other image, and seems to be nearer the patient. Further- more : — /. 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 outer quad- rant of the retina. In order to do away with or to diminish the diplopia the patient inclines his head forward and turns it to the side of the good eye. For the prismatic correction of the diplopia two prisms will be required, one with its base downward in front of the left eye to correct the vertical difference, and a second with its base outward in front of the right eye to correct the lateral difference. To make the diagnosis between the foregoing paralysis and paralysis of the left inf. rectus, — in which the diplopia is also below the horizontal plane only and the image of the left eye also lower than that of the right,— it has merely to be remem- bered that there is here crossed — instead of homonyrnous — diplo- pia, because the superior oblique, which now chiefly effects the downward motion of the eyeball, turns it at the same time some- what outward, and that the image of the left eye is inclined toward the left instead of toward the right, because the inf. rectus inclines the vertical meridian outward, and, therefore, when its action is lost the eye is committed to the action of the 436 DISEASES OF THE EYE. superior oblique, which gives it a wheel- motion inward. The figures 147 and 148 will assist in this explanation. Paralysis of the Internal Rectus, Superior Rectus, Inferior Rectus, Inferior Oblique, and Levator Palpebrae. — Complete paralysis of all the branches of the third nerve produces a re- markable appearance. The upper lid droops (ptosis), 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 lost to it. Motion in- ward exists but to a slight degree, and motion downward is effected only by aid of the superior oblique, and is accompanied by marked inward wheel-motion. If the paralysis be of some Fig. 147. Fig. 148. Fig. 147. — Paralysis of Left Inf. Rectus. Crossed diplopia. A, image of right eye ; B, Image of left eye. Fig. 148. — Paralysis of Left Superior Oblique. Homonymous diplo- pia. A^, Image of right eye ; B^, Image of left eye. little standing the external rectus obtains rule over the eyeball and rotates it permanently outward. The diagnosis, then, in cases of complete paralysis of all branches of the nerve is easily made ; but not so, sometimes, if the paralysis be only partial. The examination of the double images then is of value. If (see Fig. 149) the left third nerve be partially paralyzed in all 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 toward the patient's right at the least, and the lateral distance between THE ORBITAL MUSCLES. 437 the images will increase as the visual object is carried further toward the right. When the visual object is held aloft, the left eye will remain behind — for want of the action of both of the muscles which turn the eye upward — 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 toward the Fig. 149. latter image, in consequence of the inward wheel-motion im- parted to the eye by the superior oblique. When in each eye some branches of the third are paralyzed, the diagnosis is often extremely complicated. The ptosis, how- ever, which is nearly always present and is readily recognized, 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 upward must be due to paralysis of the third nerve ; but if there be loss of motion downward the differential diagnosis between paralysis 438 DISEASES OF THE EYE. Left Sup.Hect. Rtght Sup.Mcpt. Left I/ifllect Inf. nect of the inferior rectus and of the superior oblique has to be made. For this see the paragraph on paralysis of the latter muscle (p. 433). ^^" '^ ' As may be imagined from the foregoing, it is often diffi- cult in practice to keep clearly before one's mind the differ- ent actions of the orbital muscles, and, from the char- acter of the diplopia, to de- duce the paralysis which may be present. An aid in this respect has been provided by Dr. Louis Werner* by means of two diagrams (Figs. 150 and 151). The form of diplopia which characterizes paralysis of each muscle is expressed by the position of the dotted line bearing the name of the muscle. The dotted lines represent the ^^" " false images," the continu- ous lines the " true images." f In the case of the recti (Fig. 150) the false images en- close a lozenge-shaped space situated between the true ones, whereas in the case of the oblique muscles (Fig. 151) the true images, which, for the sake of simplicity, are combined in one line, lie be- tween the four "false im- ages," which diverge from one another so as to form an X Left Inf.'OU. litght Inf OU Left Sap OU. Jlighb Sup. OU. It * Ophthalmic Review^ March, 1886. t The "false image" corresponds to the affected eye, and the "true image" to the sound eye. THE ORBITAL MUSCLES. 439 will also be noted that the dotted lines extend upward and down- ward beyond the others, indicating respectively that the " false images" are higher or lower than the true ones. Another fact which the diagrams indicate is that, in the case of the muscles represented in the upper halves of the figures, the diplopia occurs in the upper 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 in- stance, 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 portion of Fig. 150 (recti), which gives the diplopia. If we analyze this we find : (1) That the diplopia is " crossed,'" for the false image corresponding to the left eye is on the 7nght of the true image, i. e., the right image corresponds to the left eye ; (2) that the false image has its upper end in- clined toward 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 same rules also apply to the obliques (Fig. 151), with one difference. The recti move the eye in the direction indicated by their names, the superior moving it upward and the inferior downward ; but in the case of the obliques the reverse takes place, the superior oblique moving the eye downward and the inferior upward. Therefore, for the superior obliques we must look at the lower half of Fig. 151, and for the inferior obliques at the upper part. 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. 440 DISEASES OF THE EYE. The Causes of Peripheral Paralyses of Orbital Muscles are chiefly of rheumatic or syphilitic nature. Rheumatic paralysis, to which the external rectus is specially prone, will be noted if there are symptoms of general rheuma- tism, or if there is a history of exposure to cold or wet immedi- ately preceding the attack. Syphilis will be suggested as a cause, if there be a specific history, and that other causes can be excluded. 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 neoplastic growths can, of course, cause these paralyses in the same way. 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 antagonist muscle often becomes contracted, and the eye is then rotated permanently and exces- sively 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 advantage. 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, and, by aid of cocaine, this can now be done painlessly. Dr. Buzzard's method * seems to be a very admir- * Trans. Ophth. Sac, vol. ix, p. 191. THE ORBITAL MUSCLES. 441 able one. He applies a moistened plate rheophore to the nape of the patient's neck and connects it with one pole of a Leclanche battery. He then takes the other rheophore, well wetted, in his left hand, and, securing good contact with the skin of his palm, applies the index finger of his right hand to the patient's globe, in the situation of the various external muscles of the eye. The finger is covered with a single thickness of well-moistened muslin ; the conjunctiva should be previously- rendered insensitive by cocaine. The strength of the current advised is from 1.5 to 2 milliamperes, and the alternate applica- tion 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 orthopaedic 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 paralyzed 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 movements are continued for about a minute, once a day, and cocaine is 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 neutralize 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 neutralize the diplopia is selected, in order that, with a little effort, the weak muscle * First proposed by Prof. J. Michel, Klin. Monatshl. f. Augenheilk., 1887, p. 373. 442 DISEASES OF THE EYE. may be enabled to bring about single vision, and this effort having been successfully maintained for some days, a still weaker prism is then prescribed, and so on. It is very 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. Surgical treatment is justifiable only when other means have failed to restore muscular equilibrium. If the deviation amount to 3 or 4 mm., tenotomy of the antagonistic muscle, with subse- quent tenotomy of the associate muscle in the other eye, will be sufficient ; but if the deviation amount to 5 or 6 mm., advance- ment of the paralyzed muscle in addition to the tenotomy may be required. This surgical treatment, applied to the internal and external rectus, gives satisfactory results, but in case of the superior and inferior recti it is not so satisfactory, while the oblique muscles should not be operated on. A peculiar and rare form of peripheral paralysis is Intermit- ting Paralysis of one Third Xerve. The patients are generally children or young adults who usually suffer from headache on the side corresponding to the paralyzed eye. The paralysis may be complete or partial and the attack varies in its duration from a few days to a few months. Some cases are purely periodical, i. e., in the intervals between the attacks of paralysis all the mus- cles supplied by the third nerve act in a completely normal manner, while in other cases those muscles, or some of them, do not completely recover their functions in the intervals. We are as yet quite in the dark as to the cause of these periodical paral- yses of the third nerve. Some hold that the purely periodical cases are of a functional nature, possibly hysterical or reflex, 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, while others are of opinion that both forms depend upon a diseased process at the base. In intermitting paralysis tJie Prognosis of the purely peri- odical form is favorable, inasmuch as the attacks in the course THE ORBITAL MUSCLES. 443 of time become fewer and less severe, until, finally, they cease entirely. In the exacerbating form the prognosis for complete recovery is less favorable. 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. The third class of paralyses of orbital muscles above enumer- ated — 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 remarkable cases in which all, or nearly all, the orbital muscles of both eyes are paralyzed, while the intraocular muscles often remain intact. There can be no doubt, however, that these cases do not diflfer in their nature from many of those in which, in one eye, several orbital muscles supplied by difl^erent nerves, e. g., the third and fourth, are wholly or partially paralyzed ; or where all the orbital muscles in one eye are wholly or partially paralyzed ; or where in each eye muscles supplied by the same nerve, e. g., both sixth nerves, are wholly or partially paralyzed ; 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 intraocular muscles should retain their functions, but cases occur in which the sphincter iridis and cili- ary muscles are paralyzed. When these two latter muscles alone are paralyzed the condi- tion is called Ophthalmoplegia Interna. When both they and groups of orbital muscles are paralyzed the terms Ophthalmo- plegia Interna et Externa, or Ophthalmoplegia Universa, are employed. The term Nuclear Paralysis indicates any orbital paralysis due to a lesion of the nuclei of the orbital nerves in the pons, and ophthalmoplegia externa comes within this category. The ptosis, even in cases of complete binocular ophthalmo- 444 DISEASES OF THE EYE. plegia 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 permanently 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 inflamma- tory 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 hemorrhagic lesions. The acute inflammatory cases are apt to have a sudden onset, attended with fever, headache, vomiting, and convul- sions, 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. 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 con- founded with acute nuclear palsy. The symptoms of the two states are the same, except that in the cases of peripheral neuritis there are no head symptoms at the commencement. The onset of acute hemorrhagic ophthalmoplegia is sudden, but unattended by headache, vomiting, or convulsions. It takes different courses. Sometimes it is rapidly fatal, again' it goes on to softening of the nuclei and becomes chronic, while again it undergoes a slow cure. THE ORBITAL MUSCLES. 445 It is extremely probable that to this hemorrhagic class the paralyses of orbital muscles belong which sometimes follow 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 un- common, and are probably to be classed as nuclear. The same may be said of orbital paralyses in lead-poisoning and in epidemic influenza (" la grippe "). The Prognosis in all these instances is very favorable. Chronic Nuclear Paralysis is much more common than the acute form. It depends 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. Coarse lesions, especially tumors of the pons and of its neigh- borhood which press on it, may produce orbital paralyses closely simulating those due to nuclear lesions. But here the paralysis is only one of the symptoms in the case, which are likely to include headache, vomiting, optic neuritis, hemianopsia, hemiplegia, etc. Softenings, patches of dissemi- nated sclerosis, and internal hydrocephalus with over-distention 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 ar- riving at a diagnosis, which will sometimes be difficult enough. 446 DISEASES OF THE EYE. Conjugate Lateral Paralysis of the eyes is a symptom which may be caused by a lesion in the pons. We believe that the voluntary motor impulses, coming down from the cortex to pro- duce 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 through fibres called the posterior longi- tudinal bands, under the corpora quadrigemina, and join with the fibres of the opposite third pair for the supply of the internal rectus of that side. The sixth pair of one side supplies in this way the external rectus of its own side, and, to a slight extent, the internal rectus .of the opposite side, and it is quite probable that similar decussations may exist in the nerve supply of other orbital muscles. Hence a lesion at, let us say, the left sixth nerve nucleus would paralyze the conjugate lateral motions of the eyes toward the left side, and there would, in consequence, be conjugate lateral deviation of the eyes toward the right — the eyes look away from the lesion. In conjugate paralysis or deviation, whether due to a pontine lesion, or, as in the next paragraph, to a cerebral lesion, the combined action of the internal recti for the purpose of convergence of the eyes is retained. Cerebral Paralysis 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 symptoms which aid us in localizing, more or less ac- curately, the lesions which cause them. These paralyses are always physiological, associated, or conjugate, as they are vari- ously and with equal correctness 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 asso- THE ORBITAL MUSCLES. 447 ciated lateral motions of the eyes is situated. But, eveu if we did know its position, it is not likely that much would be gained, so far as clinical localization 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 distant symptom, especially in cerebral hemorrhage, when it is often accompanied by a rotation of the head in the same direc- tion 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 hemisphere, and, hence, even when conjugate lateral deviation plays the part of a direct cortical symptom, it can never be recognized as such, owing to its evanescent charac- ter. In paralyzing lesions the deviation of the eyes is, of course, toward 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 affected muscles causes the deviation to be from the side of the lesion. These conditions are the reverse of what hap- pens in conjugate lateral deviation due to lesions in the pons (p. 446), and we are thus enabled to differentiate between lesions in the two positions. There are four possible cases : — p h 1 T ■ [Destructive. Eyes turned away from paralyzed side. I Irritative. " " toward convulsed side. ■pv ^. T • f Destructive. " " toward paralytic side. Pontine Lesions, i^ . . ,, ,, r t j -j •■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 in- nervated by the right hemisphere of the brain, consequently a de- structive lesion here would produce paralysis of the left side of the body, and of the associated movements of the above orbital mus- cles, and therefore the eyes would be drawn to the right by their opponents, i, e., away from the paralyzed side. A destructive 448 DISEASES OF THE EYE. Fig. 152. lesion of the right side of the pons would also, of course, pro- duce paralysis of the left side of the body ; but, involving the right sixth nucleus, 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 op- ponents, i. e., toward the para- lyzed side. The reverse of the foregoing would occur in irritative lesions. Fig. 152 will serve to illustrate the points referred to. A destructive lesion at 12, the right cortical centre, involv- ing also motor centres of the body, would cause left hemiple- gia ; and, since the external rectus of the left eye and in- ternal rectus of the right eye would be paralyzed, the antago- nists would turn the eyes to the right, {. e., away from the para- lyzed side. A destructive lesion of the right side of the pons, also producing left hemiplegia, if it involve the sixth nucleus, will produce paralysis of the external rectus of the right eye and of the internal rectus of the left eye, and then the antago- nists would turn the eyes to the left, i. e., toward the paralyzed side. It is easy to see how irritative lesions would produce ex- actly the opposite effects. It may be of interest here, even at the risk of some repetition, to direct special attention to 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, longi- tudinal bands from sixth nerve to opposite third nerve ; 9. Nucleus left sixth nerve ; 10. Nucleus right sixth nerve ; 11 and 12. Left and right cortical centres. An im- pulse starting from 12 would travel down to 9, and produce an asso- ciated movement of the eyes to the left. THE ORBITAL MUSCLES. 449 The Localizing 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 paralyzed. That a separate cortical centre for this branch of the third nerve exists, and that it innervates the mus- cle 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. IN'o doubt the power to voluntarily innervate one levator and orbicu- laris alone varies in different individuals, and in many persons the levator centres are practically associated centres, and prob- ably this is the reason why cerebral ptosis is rather rare. The position of this centre is still an open question, for the view that it is situated in the posterior part of the inferior parietal lobule has not met with general acceptance. 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 symp- tom in disease of the pons, without paralysis of the other branches of the third nerve — except, sometimes, in so far as conjugate deviation (vide sujjra) 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 localize a lesion in the crus cerebri. When the third nerve is paralyzed by a lesion in this situation, it is the rule to find it paralyzed as a whole, but paralysis of only some of the 88 450 DISEASES OF THE EYE. third-nerve branches may be produced by a lesion of the cere- bral peduncle, and the branch to the levator palpebrse seems to be the one most frequently implicated alone. In order now to complete this subject of ptosis as a focal symptom, I must refer to a rare form of it which has been described by Nothnagel, and which does not depend on a lesion of the third nerve. It may be called sympathetic, or pseudo-ptosis, and 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, this author says, there is : 1 . Apparent ptosis on the paralyzed side, owing to the contraction of the palpebral aperture, but the lid can be raised. 2. Con- traction of the pupil on the same side. 3. A shrinking back of the eyeball into the orbit, so that it seems to have become smaller. 4. An abnormal secretion of thin mucus from the corresponding nostril, of tears from the affected eye, and of saliva from the corresponding side of the mouth. Nothnagel states he has found this train of symptoms in lesions of the corpus striatum. 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 of 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. But the localizing 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 different times they may be due to two distinct lesions, neither of which may be in the crus ; for the hemi- plegia 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 hemi- plegia by a considerable interval. THE ORBITAL MUSCLES. 451 That basal lesions are by far the most frequent cause of paralysis of the third nerve is beyond a doubt : and here it is usual, but not constant, to find it paralyzed in all its branches. The diagnosis to be made, when direct symptoms are being con- sidered, is, for the most part, between a lesion in the crus and a lesion at the base. AVe 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 I heva already referred, 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 paralysis 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. But into all this I need not enter here. Third-nerve symptoms — in addition to those included under the headings, conjugate deviation, or paralysis and ptosis — are sometimes distant symptoms. Tumors of the cerebral hemi- spheres, 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 symp- toms are, 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 Xerve, when combined with paralysis of other motor eye-nerves, is difficult to recognize, and con- sequently, in such cases, it supplies but little aid for localization. Solitary paralysis of this nerve, as a symptom of cerebral focal lesion, is extremely rare. Xieden has placed a case on record in which paralysis of one fourth nerve was the only focal symptom to which a tumor 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. In combination with paralysis 452 DISEASES OF THE EYE. of the third nerve it speaks for a lesion in the cerebral peduncle extending back to the valve of Vieussens, and has, I believe, been utilized by Meynert in this sense. 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 dis- tant symptom as the sixth. Gowers refers this liability to the lengthened course these nerves take over the most prominent part of the pons, which renders them readily affected by distant pres- sure. One or both nerves may in this way be paralyzed. Wer- nicke states that sixth-nerve paralysis is most apt to be present as a distant symptom when the lesion, especially a tumor, is situated in the cerebellum ; differing in this way from the third nerve, which, as I have said, 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 pons, usually a hemorrhage, on the side corresponding to the paralyzed nerve. We know that the fifth and facial, and some- times the auditory, spinal accessory and hypoglossal nerves may all, in varying combinations, form one of the elements in a crossed paralysis from a lesion in this position, but if special localizing 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. Paralysis of the facial with the sixth is not an uncommon combination caused by a lesion in the pons, which at the same time produces hemiplegia of the opposite side of the body. This combination is a natural one, in view of the close relations of the nuclei of the sixth and seventh nerves. Indeed, Lock- hart Clarke, Meynert, and others are of opinion that there is one nucleus which is common to both nerves, a view not shared in by Gowers and others. The manner in which the root of the facial nerve winds round the sixth-nerve nucleus must also have THE ORBITAL MUSCLES. 453 an important bearing on the occurrence of associated paralyses of these nerves. Hemiplegia due to a lesion of the cortical motor region, which 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 the latter is a crossed paralysis, the former is homony- mous. Convergent Concomitant 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. The term "concomitant" {concomitatus, accompanied) is given to it in contradistinction to " paralytic " strabismus, because in it the squinting eye, by virtue of the normal innervation of the associated muscles, accompanies the straight one in all its move- ments to an equal extent. At the primary position of the eye- balls, 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, if the straight eye be shaded by the surgeon's left hand, and the squinting eye by this means be obliged to fix the object of vision — e. g., the tip of the index finger of the surgeon's right hand held up two or more feet distant in the median line — it will be found that the straight eye is now squinting inward. This deviation of the straight eye is called the secondary deviation, and in these cases of concomitant strabismus it 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 rec- tus of the squinting eye, when the latter muscle is forced, in the foregoing experiment, to roll its eye outward in order to bring it 454 DISEASES OF THE EYE. to fixation, the internal rectus of the good eye, receiving a simi- lar nervous impulse, rolls that eye inward to the same extent as the squinting eye has been rolled outward ; and the good eye will therefore present, under the covering hand, an internal strabismus of the same amount as that which had 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 stra- bismus from the paralytic form, in which the secondary deviation is greater than the primary one (see General Principle No. 2, p. 430). In order to decide which is the squinting eye, it is merely necessary to direct the patient to look at an object held up in the median line on a level with his eyes and a few feet in front of him. In concomitant strabismus, of course, both eyes never squint simultaneously, as one hears it sometimes stated by parents. Causes. — Squint is never due, as is popularly supposed, to fright, imitation, or naughtiness, nor is it ever brought on by the patient looking at a lock of hair or other object which may happen to hang very much to one side. Donders^ pointed out that in a large proportion of cases of convergent strabismus the condition of refraction is hyper- metropia, 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 (Chap. I, p. 12) that with each degree of normal convergence of the optic axes a certain effort of accommodation is associated. The greater the angle of normal convergence, the greater the possible effort of accommodation. Of this physiological fact, Donders said, the hypermetrope often unconsciously takes advantage, and, in order to brace up his accommodation in an excessive degree for the sake of distinct vision with one eye, he increases the angle of con- vergence of the optic axes by rotating the other eye (i. Fig. 153) somewhat inward. The angle I' is thus made larger than " Accommodation and Refraction of the Eye," p. 292. THE ORBITAL MUSCLES. 455 the angle /, and the effort of accommodation normally belong- ing to the angle V is obtained for the eye R, which, consequently, receives a clearer image of the visual object A on its retina. But, inasmuch as all hypermetropes do not squint. Bonders considered that there were contributing circumstances which caused each hypermetrope to unconsciously decide between distinct monocular vision with strabismus and indistinct bin- ocular vision. The latter, he said, is likely to be preferred if the condition of the refraction and the acuteness of vision is the same in each eye, while if the retinal images differ much. Fig. 153. by reason of one eye being more ametropic than its fellow, or from nebulae of cornea, or from other causes, the desire for binocular vision would be less strong, and the imperfect eye would deviate inward for the sake of the resulting increase of accommodation in the perfect eye. It is admitted on all hands that hypermetropia is one of the causes of internal strabismus, but, as Schweigger* has *"Ueber das Schielen," (Berlin, 1881), and " Handbuch der Augen- heilkunde," 5th ed., p. 146. 456 DISEASES OF THE EYE. pointed out, 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 acuteuess of vision is very defective in one eye. 2. According to Donders' theory, the higher the degree of the hyper- metropia, the greater should be the tendency to strabismus; and yet, clinical observation shows that this is not the case. 3. In periodical strabismus the influence of hypermetropia and of the accommodative ejffort 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 4. Don- ders' theory fails to explain the occurrence of convergent strabismus in emmetropic and in myopic individuals, where, of course, no excessive efibrt of accommodation is required. Schweigger considers that a want of equilibrium between the muscles is the chief cause of strabismus (divergent as well as convergent), and that convergent strabismus is mainly due to a preponderance in the power of the internal over the external recti; or, with equal accuracy one might say, to an insufficiency of the external recti. It would seem that, in hypermetropia, the external recti are apt to be congenitally less powerful than the internal recti, while in myopia congenital insufficiency of the internal recti is the more common condition. The in- ternal recti do, however, sometimes preponderate in emme- tropia and even in myopia, and, therefore, convergent stra- bismus does sometimes occur in these forms of refraction. Whatever be the condition of refraction, strabismus is more apt to be developed if the value of binocular vision be dimin- ished by imperfect sight in one eye. Spontaneous cure of strabismus does sometimes take place, THE ORBITAL MUSCLES. 457 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 Bonders' theory. According to Hansen Grut's view,* convergent squint origi- nates in, and is maintained as the result of, an innervation which induces in the interni a shortening exceeding in amount that which is desirable. Single Vision in Concomitant Convergent Strabismus. — For the most part, these patients do not complain of double vision, although diplopia is the rule in cases of convergent strabismus due to paralysis of the external rectus. 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 inside 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 con- comitant form? The only explanation of this circumstance which had been, until within the last few years, put forward was, that convergent concomitant strabismus being a quasi- physiological condition, the patient's mind involuntarily sup- presses 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 unper- ceived, 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 initio more defective (macula cornea, higher degree of hypermetropia, astigmatism, etc.) than its fellow, and it was held that this, too, *" Bowman Lecture," 1889. 39 468 DISEASES OF THE EYE. rendered suppression of its image more easy. Such a suppres- sion of the image is possible, and it no doubt does occur in many- cases of strabismus, but it is certain, as pointed out by Schweigger, that it does not occur in all of them, perhaps not even in most of them. It would be beyond the scope of this handbook were I to go into the argumeuts on this point. Suffice it to say, that in those cases where suppression of the image of the squinting eye does not take place, a certain partici- pation in the act of vision on the part of this eye, when not too blind, is implied. One of two events takes place in those cases: Either the region of the retina, on which, in the squint- ing eye, the image of the visual object is formed, becomes func- tionally 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 actu- ally 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. I shall mention one fact in support of each, but must refrain from entering more deeply into the subject. In support of the first is the occurrence, not rarely observed, of crossed diplopia after operation for concomitant convergent strabismus ; 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. 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. Schweigger states the pro- portion of these amblyopic cases to be thirty per cent., but I believe the percentage to be much larger. 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 sup- pression of the image on its retina, and, hence, it is termed amblyopia ex anopsia. If this view were the correct one, we THE ORBITAL MUSCLES. 459 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 fact, the eye should be almost useless — in adults who have not been operated on and in whom raonolateral strabis- mus had been present since childhood. And yet marked ambly- opia 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 progressive, 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 inward more than before — (amblyopia with eccentric fixation) — and, in less well-marked cases of the same sort, although there is no eccentric 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 character- istic of amblyopia ex anopsia, and is the result of the strabis- mus; but it is identical with a form of congenital amblyopia often present in only one eye without strabismus (p. 417). A strong argument in favor of amblyopia ex anopsia is the im- provement which often seems to take place in the vision of the squinting eye by systematic separate use, or after the strabotomy. But it is tolerably certain that where the improvement takes place, the defective vision has been due rather to retinal asthe- nopia 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 unfavorable to the amblyopia ex anopsia theory. The circumstance that in alternating strabismus the sight of each eye is good cannot be regarded as proof in favor of amblyopia ex anopsia rather than against it. The explanation which Schweigger gives of the very frequent presence of amblyopia in the squinting eye is that it is cougen- 460 DISEASES OF THE EYE. Fig. 154. ital, 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. There are Three Clinical Varieties of Convergent Concomitant Strabismus. — 1. Periodic. 2. Permanent alternating. 3. Permanent monolateral. Periodic strabismus occurs only when some great effort of accommodation is required. It sometimes is the first stage of permanent monolateral or of alternating stra- bismus ; but these two latter forms do not always have their be- ginning in the periodic form, which often continues as periodic to the end of the chapter. In alternating strabismus the patient squints sometimes with one eye and some- times with the other. In permanent monolateral strabismus the squint is con- fined to one eye. Measurement of Convergent Strabismus. — The amount, or degree, of the devia- tion of the squinting eye from its normal position is not the same in every case, and the size of the squint is measured by one of the following methods. Which- ever of them be used, it is important that the patient be directed, during the test, to regard a distant object placed in the median line and on a level with his eyes. If he look at a near object, the squint may be over-estimated, by reason of its increase with accommodation. 1. By the Linear Method we measure the number of millimetres by which the eye deviates from its normal position. The good eye is shaded, and the squinting eye is caused to fix an object in the median line — by preference a distant ob- ject. Close under the margin of the lid a strabometer (Fig. 154) is then placed, so that the point may coincide with a THE ORBITAL MUSCLES. 461 perpendicular let fall from the centre of the cornea. The shade being removed from the good eye, the squinting eye is allowed to resume its abnormal position, and the degrees recorded on the instrument, under a perpendicular let fall from the centre of the cornea in this position, are read off. They give the amount of the deviation. 2. Hirschberg's Method* consists in estimating the degree of deviation by the position of the corneal reflex of a candle flame held straight in front of, and about a foot from, the eye. 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 Fig. 155. ntedium f^mlTij jjimil -mnrf/u/ of' coriif fi eye. In a convergent squinting eye it is displaced outward, and Hirschberg recognizes five groups of strabismus. Group 1 (Fig. 155, representing the right eye), in which the reflex is nearer to the centre than to the margin of the pupil. This represents a strabismus of less than 10°, and no operation is indicated. Group 2, in which the reflex is at or about the margin of the pupil ; representing a strabismus of 12° to 15°, and indicating a simple tenotomy, with occasionally a tenotomy of the other int. rectus. Group 3, in which the reflex is outside the pupillary margin, about half-way between the centre of the pupil and the corneal margin. This represents a strabismus of about 25°, and indicates a tenotomy of the internal rectus, com- Centralhlatt f. p. Augenheilkunde, 1886, p. 5. 462 DISEASES OF THE EYE. bined with a moderate advancement of the external rectus. Occasionally, later on, a tenotomy of the other internal rectus will be required. Group 4, in which the reflex is on or near the corneal margin ; representing a strabismus of 45° to 50°, and indicating a tenotomy of the internal rectus, along with energetic advancement of the external rectus, and sometimes a later tenotomy of the other internal rectus. 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°, and requires the combined operation, with strongest pos- sible advancement of the externus. Even this is sometimes insuflicient, and a tenotomy of the internal rectus, or even the combined operation on the other eye, may be subsequently required. This is a modification of the linear method, and is a convenient one in routine practice. 3. Priestley Smith measures strabismus by means of a double tape, used in conjunction with 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 which holds the ophthalmoscope ; 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 toward 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. 157 illustrates the measurement of a convergent strabis- mus 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 (X), I. e., the fixing eye. He sees the corneal reflex in the centre of the pupil, and knows thereby that this eye is fixing properly. He then throws the light on the right eye (i?), and sees the reflex situated eccentrically outward, and knows that this eye deviates inward. Taking the graduated tape between THE ORBITAL MUSCLES. 463 the fingers of his left hand, and telling the patient to watch this hand, he moves it outward along the tape (see Fig. 156), and meanwhile watches the corneal reflex in the deviating eye. When this latter reaches the middle of the Fig. 156. P O pupil, he reads the position of the hand upon the tape. The axis of the deviating eye (i?) has moved from R' to 0, through the angle R' R 0. The axis of the non-deviating eye (X) has moved through an equal angle, L U. The angular movement of X,as measured by the tape, equals the angular deviation ofi?. 464 DISEASES OF THE EYE. Fig. 158 illustrates the measurement of a divergent strabismus of the right eye. The hands must be reversed, but the principle is the same as before. The graduated tape is a substitute for a graduated arc of a circle, but does not exactly correspond with such an arc ; the error involved is, however, so small as to be of no importance, if the observer keep his two hands at about the same distance Fig. 159. from the patient's face. In this mode of measuring a strabismus it is the excursion of the fixing eye which is actually measured, and the excursion of the deviating eye is supposed to be equal to it. If the excursions of the two eyes are unequal, the result would be at fault. The method, though difficult to explain in words, is very quick and satisfactory in practice. 4. The Angular Method. — The object aimed at here is to de- THE ORBITAL MUSCLES. 465 termine the size of the angle which the visual axis of the squinting eye makes, with the direction it should normally have. For this purpose a perimeter is employed. Let us suppose that the right eye (B, Fig. 159) be the squinting eye, and that P o P be the arc of the perimeter. The patient is placed at the instru- ment, 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 P should now pass through the point o, but it passes through the point n, and therefore o P n is the angle of the strabismus. The surgeon finds the position of n by carrying the flame of a candle along the perimeter, until, with his eye placed behind the flame, he finds that the corneal image of the flame occupies the centre of the pupil. The flame itself will then be at n, and the size of the squint-angle may be read oflf there. This gives us the optical axis of the eye; but, to be strictly accurate, we must remember that the position of the visual axis is what we require, and that it lies a few degrees further inward, according to the size of the angle y. The angular method is now in general use instead of the linear method, than which it is more accurate. 5. A good subjective method for determining the dimension of a strabismus, but which can only be used where diplopia is present, is what may be called the Method by Tangents. Upon a wall of the consulting-room, in a horizontal line, and so as to be on a level with the eyes of the patient, who is placed about three metres from the wall, are, permanently marked out, tangents of angles of 5° each, as seen from the place where the squinting eye is. Exactly opposite to the squinting eye is 0°, while toward the right and left the points are marked up to 45° or more. The flame of a candle being held at 0°, and one eye of the patient being covered with a red glass, he is called on to indicate the position of the image belonging to the squinting eye, and the number on the wall which corresponds to this gives the angle of the strabismus. For the purpose of estimating paralyses of the orbital muscles, a similar row of tangents, or several such, may be marked out in the vertical direction. Xo 466 DISEASES OF THE EYE. well-ordered ophthalmic institution should be without this simple arrangement. Mohility of the Eye Outward in Convergent Concomitant Stra- bismus. — This is often defective in the squinting eye, and some- times also in the fixing eye. The excursiveness of the lateral motions of the eyeball may be measured by the perimeter. Placing the patient as though the field of vision, say of his right eye, were about to be examined, the patient is directed to follow with his eye the flame of a candle carried along the perimeter from 0° toward 90° in the temporal direction, and when it is found that the eye cannot be turned any further in this direction, the extreme position is noted by the position of the candle at the perimeter. The corneal image of the flame must, of course, be central when the position of the flame is read ofi*. In a similar way, the mobility of the eye inward may be measured. In the normal eye the mobility in each direction is about 45°. 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. Treatment. — The bearing of hypermetropia on the production of many cases of strabismus long since suggested the idea of curing the deviation by spectacles which would correct any existing hypermetropia. The accommodation having been para- lyzed by atropine, is kept under its influence for some weeks or months"; spectacles which completely correct the hypermetropia and astigmatism being meantime constantly worn. Should the patient require to use his eyes for near work while under treat- ment, it is necessary that he should have suitably higher -|- glasses for his near work. Occasionally, good cures are effected by this means; and, when a periodic strabismus in a child comes under my care, I always think it worth while to attempt its cor- rection in this way ; but, in general, it is, by itself, of no use whatever. Orthoptic Treatment. — To Javal * is due the credit of devising * Ajinales d' Oculist i que, Juillet et Aodt, 1871. See also Mars et Avril, Mai et Juin, and Nov. et Dec, for the same year. THE ORBITAL MUSCLES. 467 this method ; but, although he did so some years ago, it is only recently that the treatment has been introduced into practical ophthalmology. In order that the treatment may be carried out, it is necessary, in the first instance, that the strabismic person should have diplopia. If the latter be not present spontaneously, it has to be developed ; and it is sometimes possible, when the sight in the squinting eye is not too defective, to give the patient diplopia, i. e., to make him continuously conscious of the presence of the image belonging to the squinting eye. This may be done by means of exercises with a prism, base downward, before the deviated eye, and a candle flame as visual object. The exercises are to be repeated daily until diplopia without a prism is established. Javal recommends the following exercise to develop diplopia : A screen — e. g., a large sheet of cardboard — is held vertically between the two eyes, while the patient is directed to look at a candle flame about two metres in front of him. Double vision may immediately appear ; but, if it does not, it may be brought out by now and then covering the good eye for a moment, or by placing before it a red glass, which can soon be done without. Less brilliant visual objects are gradually substituted, until, finally, the double vision will continue even when, at first cautiously, the screen is removed. Double vision having been established, we proceed to enable the patient to fuse the double images, i. e., to obtain binocular vision, and when we have succeeded in doing this, we have cured the squint. The end in view is best efiected by means of a stereoscope, into which, in place of the usual prisms, -|- 6 D lenses have been introduced. The focal distance of these lenses being about the length of an ordinary stereoscope, rays coming from the slides, and passing through them, fall into the observer's eye as parallel rays, the accommodation, consequently, is sus- pended, and, under normal conditions, the visual lines are parallel, as though looking at a distant object. In the normal state the double picture, or diagram, will seem to be single, but to the strabismic patient in whom diplopia is present it will be 468 DISEASES OF THE EYE. double. Our duty, then, is to diminish the distance between the pictures, until the patient finds himself just able to fuse the images into a single impression. After a day or two the distance is increased slightly, and so on, until, finally, the normal position is reached. It is needless to say that in these exercises all errors of refraction must be eliminated by the proper glasses."^' The pictures used in the stereoscope should be geometrical figures, or specially designed pictures, in order that both surgeon and patient may the more readily recognize their fusion. Only the very slight degrees of strabismus are adapted for the attempt at cure by orthoptic treatment. A marked deviation will not be amenable to it. Moreover, it makes demands both upon the patience and intelligence of the patient, which are *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 holding a cedar pencil half-way between his eyes and the page, perpendicularly 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 surgeon 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 cylinder about 25 cm. long, and wide enough to take in both eyes of a person, is arranged, 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 cylinder, but which are bent outward sufficiently to keep them out of 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. During the experiment the thread is in the hori- zontal 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 thread, 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. THE ORBITAL MUSCLES. 469 rarely fulfilled, especially in hospital practice. A field more fertile in good results for this treatment is found in the com- pletion of cures which have been commenced by operative measures. Operative Treatment. — Division of the tendon of the internal rectus muscle, combined, sometimes, with advancement of the insertion of the external rectus, is the measure which has to be applied in most of the cases which come under our notice. I am strongly opposed to operative interference in patients under five years of age, and very much prefer that they should be seven or eight years old, or even older. Early childhood ofl?ers a decided obstacle to the careful adjustment of the operation and to orthoptic treatment. In order that the operative proceeding may be adapted to each case, the following points must have been previously noted with care : a. The dimension of the strabismus angle, h. The lateral mobility of the eyes, especially the mobility outward of the squinting eye. c. The refraction of the eyes and the acuteness of vision of the squinting eye, as well as the presence or otherwise of diplopia : The first, in order that glasses for the correction of any hypermetropia may be worn if desirable after the operation ; the second, because, ceteris jmrihiis, an operation for convergent strabismus will produce a more marked effect if the vision in the squinting eye be good than if it be very defective ; and the third, because the presence of diplopia encourages the hope that binocular vision may- be restored. Kules which will ensure in every case, with absolute certainty, the desired degree of operative effect cannot be laid down. The following will be found to answer in the majority of cases, and, if the effect be now and then too great, it can easily be adjusted by bringing forward the internal rectus, or by setting back the external rectus, within a few days after the operation. In every instance it should be the desire of the surgeon to leave 2° or 3° of strabismus behind ; 470 DISEASES OF THE EYE. for the effect of the operation is apt to increase within a year, and, if absolute parallelism be present at first, divergence may ultimately supervene. The establishment of binocular vision, when possible, would do away with this remnant of strabismus ; but, under any circumstances, the latter does not detract from the cosmetic result. If the vision of the squinting eye be fairly good, and the deviation amount to not more than 15° or 20°, and the power of the external rectus be sufficient, the correction can be effected by the tenotomy of the internal rectus of the squinting eye. A strabismus of 20° will require the free separation of the delicate connections between the anterior surface of the tendon, or capsule of Tenon, and the conjunctiva as far back as the caruncle, in order that the tendon may be free to contract. For a deviation of 15° or less this separation should not be so free, or should be quite omitted ; or, if a very slight effect be desired, it can be produced by drawing the conjunc- tival wound together after an operation which has been confined strictly to the insertion of the tendon. If the vision of the squinting eye be fairly good, and the power of the external rectus sufficient, and if the squint be more than 20°, it is advisable to divide the proceeding between the eyes, e. g., if it be 30°, about 20° are corrected by tenotomy of the internal rectus of the squinting eye and the remainder by tenotomy of the internal rectus of the fixing eye. If desired, the effect of the tenotomy in one or both eyes may be increased by a suture passed through a fold of conjunctiva at the outer side of the globe, and tied tightly. If, although the vision of the squinting eye be good, and the deviation not more than 20° or 25°, there be marked loss of power of the external rectus muscle, tenotomy of the internal rectus alone will often lead to disappointment, and a good result will require this tenotomy to be combined with advance- ment of the external rectus; the operative measures being confined to the squinting eye. But advancements in such cases THE ORBITAL MUSCLES. 471 as this must be very cautiously carried out, as an excessive effect may easily be produced. The external rectus should be but slightly brought forward. If the deviation exceeds 35°, even when there is good vision in the squinting eye and no loss of power in the external rectus, tenotomy of the internal rectus of each eye is rarely sufficient, and, as a rule, advancement of the external rectus of the squint- ing eye must be combined with these measures. With a deviation of 30° to 35° and loss of power in the ex- ternal rectus, the demand for advancement of the external rectus becomes more imperative. The correction of squints of 40° and more are, in every instance, to be effected by teno- tomy with vigorous advancement in the squinting eye, and subsequent tenotomy of the internal rectus in the good eye. In cases where the vision of the squinting eye is much reduced, the deviation great, and the insufficiency of the external rectus marked, the combined operation (f^^^^ in one or both eyes is the proper proceeding. Mode of Operating for Strabismus. — Tenotomij. — The instruments required for this operation are, a spring-stop speculum, a small-toothed forceps, a blunt scissors some- what curved on the flat, and two strabismus hooks (Fig. 160). The eye having been thoroughly cocainized, the pa- tient is placed on his back, the surgeon standing in front of him and on his left-hand 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 forceps and the eye. Into the opening thus made the points of the closed scissors are inserted, and, with a snipping action, a pas- sage is made through the subconjunctival tissue ; from the con- junctival aperture to the 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. 472 DISEASES OF THE EYE. aad, 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 for- ceps 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 ten- don, and the latter is completely divided at its insertion. The second hook is 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 the smallest segment of the tendon be left undivided, the result of the operation is apt to be unsatisfactory. Immediately after the operation a marked diminution in the mobility of the eye in- ward 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 in only a slight degree in compari- son with the supposed extent of operation, it may be concluded that the tendon is imperfectly divided, and a new search 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 inward, and to compare it with the in- ward motion of the other eye. The effect of the operation may be diminished, if found neces- sary, by drawing the edges of the conjunctival wound together with a suture, the tendon being thus prevented from uniting with the globe so far back. The more conjunctiva we include in the suture at each side of the wound, the more will the effect of the tenotomy be reduced. This restricting suture should be applied when the immediate result of the tenotomy is greater than expected or desired. THE ORBITAL MUSCLES. 473 As the edges of the conjunctival wound cannot be accurately adjusted with sutures, none are applied for that purpose. They are only used, as above, to diminish the operative effect; or, when an extensive loosening of the subconjunctival tissue has been performed, to prevent sinking of the caruncle. The Subconjunctival Operation for Strabismus, proposed by the late Mr. Critchett, is performed as follows : A fold of con- junctiva is seized, close to the lower margin of the insertion of the muscle, and incised with a blunt-pointed scissors, so as to expose the tendon. A strabismus hook is passed through the opening and under the tendon. The scissors is 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 close to its insertion. This method is very generally adopted by English surgeons. For myself, I prefer the operation (von Graefe's) previously described, 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, it is seized with the forceps with which, just before, the conjunctiva had been raised. In other respects the proceeding is the same as von Graefe'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 very marked, owing to the loosening of the tendon from its insertion. In a few days, when it becomes re-attached, the effect diminishes, and in the course of some weeks 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 con- vergence. 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 maintained at that distance, the effect will not be too great. But if, at a distance of from 18 to 20 cm., the 40 474 DISEASES OF THE EYE. operated eye ceases to converge, or begins to diverge, or if even at 12 cm. the convergence, although accomplished, cannot be maintained for more than a few moments, and that then the operated eye deviates outward, ultimate divergence may be expected, even though the actual position of the visual axes be correct. A restricting suture must be applied in such cases. Sometimes, although the patient converges up to 12 cm. satis- factorily, and maintains the convergence at that distance for some moments, the eye will then rotate inward. In such cases there is apt to be a recurrence of the strabismus. Advancement. — In cases of convergent squint, in which it is desirable to combine advancement of the external rectus with tenotomy of the internal rectus, the latter is done first, as above described, at the same sitting. An opening is then made in the conjunctiva immediately over the insertion of the external rectus, and as long as the breadth of the tendon. The band of conjunctiva 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 upper 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 low^er 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 (Fig. 161). The tendon is sepa- rated off with the scissors from the sclerotic, close to its insertion. The sutures are passed through the conjunctival flap in the direction of the muscle, and are respectively tied with their own ends. A greater or less effect is produced, according as the sutures are placed further or nearer to the insertion of the tendon, and according as they are drawn more or less tightly. I have found this method perfectly satisfactory. Immediately after the combined operation is finished, there THE ORBITAL MUSCLES. 475 should be no divergence, nor should there be marked loss of motion of the eyeball inward. In either case the effect is too great, and must at once be diminished by an adjustment of the advancing sutures, or a bringing forward of the internal rectus. In my opinion, even if it lie in the plan of the treatment to supplement the tenotomy, or combined operation^ on the squint- ing eye by a tenotomy, or combined operation, on the fixing eye, both eyes should not be operated on at one and the same Fig. 161. sitting. An interval of a fortnight or more should elapse, in order that the true effect of the first proceeding may be accu- rately gauged, and then the surgeon will be in a position to know how to regulate his operative measures for the other eye. After a strabismus operation, a light bandage is applied, and is changed morning and evening for forty-eight hours, when, if no suture has been used, it may be discarded. If sutures have been employed, the bandage is retained until they come away. Dangers of the Strabismus Operation. — I have never seen any 476 DISEASES OF THE EYE. inflammatory reaction after a strabismus operation, not even after an advancement, nor have I ever seen any serious accident during the operation. Puncture of the sclerotic with the scis- sors, while the tendon was being divided, has occurred in the hands of some operators ; but, I confess, I cannot understand how such an accident could happen, unless the operator had his own eyes shut. It is also stated that eyes have been lost after squint operations through orbital cellulitis, which, I fancy, must have been brought on by the introduction of septic matter upon the instruments. Occasionally, a small arterial branch may be divided during the 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. I have only seen the occurrence twice. Sinking of the caruncle, some months after the tenotomy, when it does rarely occur, can be remedied in the following way: The conjunctiva is divided vertically about 6 mm. from the caruncle. The inner lip of the wound is raised, a scissors curved on the flat passed in, and the subconjunctival tissue as far as under the sunken caruncle separated. The subconjunctival tissue under the outer lip of the wound, and as far as the corneal margin, is loosened in the same w^ay, and the two flaps are brought together with a suture, which includes a sufliciency of conjunctiva to draw the caruncle well forward. Treatment Subsequent to Operation. — It is generally necessary for the patient to wear the correcting spectacles for his hyper- metropia, 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 in every case ; and, by itself, affords ample reason for undertaking the operation. But a cure, in the true sense of the term, involves restoration of THE ORBITAL MUSCLES. 477 binocular vision*, and this is very rarely obtained by operative measures alone. Orthoptic exercises with the stereoscope (p. 467) are of great value in completing a cure, which has been almost effected by operation. The deviation, which has been reduced to a minimum by the operation, may sometimes be quite eliminated, and, still more important, binocular vision may sometimes be developed. Where the attending circumstances of the case, both clinical (acuteness of vision, diplopia) and personal (patience and intel- ligence of the patient), admit of it, an effort should always be made to effect such a cure. Insufficiency of Convergence, or Insufficiency of the Internal Recti Muscles, and Divergent Concomitant Strabismus. — In the normal condition, the orbital muscles are in a state of equili- brium, no one muscle, or pair of muscles, having more power over the eyeballs than its fellow. Insufficiency of the Internal Recti Muscles, or Insufficiency of Convergence, implies a disturbance of this equilibrium. The internal recti in these cases are so much weaker than the exter- nal recti, that the former are obliged to make a constant effort to prevent the eyes, or one of them, from becoming divergent, and it is only the demand for binocular vision which stimulates the muscles to this effort. Muscular Asthenopia is the symptom caused by this insuffi- ciency. The patients complain that, after reading, writing, sew- ing, or employment at other near work for a time, they begin to find the objects spreading, becoming indistinct, and perhaps doubled. Pain in and about the eyes comes on. These symp- toms gradually increase, until the work has to be discontinued. A great deal has been written within recent years upon the relationship of some nervous diseases, especially epilepsy, to ■* The importance of binocular vision consists in the fact that it is chiefly by its aid we estimate distances finely, and observe the shape of objects. Even plane surfaces are seen much more accurately with bin- ocular than with monocular vision. 478 DISEASES OF THE EYE. waut of power in one or more of the orbital muscles. It has been thought that "eye strain," from want of coordination in these muscles, sometimes aggravated, if it did not actually cause, epilepsy ; but the outcome of the whole discussion seems to be that there is no such connection. The diagnosis of insufficiency of convergence can be made by the following methods. The patient is directed to look at the tip of the surgeon's finger held up in the middle line. The finger is brought slowly closer to the eyes until a certain point is reached where the internal rectus of one eye ceases to act, the other eye still remaining in fixation. The first eye, ' upon the finger being advanced a little more, usually becomes divergent. Or, if the tip of the finger be held some 20 cm. from the patient's eyes, and if, with his other hand, the sur- geon cover one of the eyes, say the right, while the left is caused to fix the finger-tip, it will be found that the eye under the hand is diverging, and, when the hand is removed from it, it makes an inward motion, in order again to fix the finger-tip. The explanation of this is^ that, when one eye is covered, there is nothing to be gained in the way of single vision by an excessive exertion of the weak internal recti ; and, consequently, the eye which is excluded from the act of vision is abandoned to the control of the over-strong external rectus, and only re- turns to its normal position, when, being restored to participa- tion in the act of vision, diplopia would otherwise be present. The following is von Graefe's Test for Insufficiency of the Internal Recti : A dot with a line drawn vertically through it (Fig. 162) on a sheet of white paper is given to the patient to look at, at his usual reading distance. Before one eye, say the right, a prism of about 10° with its base downward is held vertically. This, in the normal condition, would produce a double image of the dot, so that the figure would seem to be a line with two dots, the upper dot being the image belonging to the right eye. In insufficiency of the interni, the image of the THE ORBITAL MUSCLES. 479 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-hand side (Fig. 163). This crossed diplopia indicates divergence. The expla- nation of the experiment is as follows : When a prism is held before the right eye, the possibility of binocular vision is removed, and, insufficiency existing, the weak internal rectus of the right eye has no object in greatly exerting itself, and con- sequently abandons the eye to the traction of the external rectus. Hence the divergence, and the projection of the image of this eye to the opposite side. The degree of insufficiency existing may be determined by this same experiment. If a weak prism be held with its base inward before the left eye, in the above case, the images of the lines will appear to be brought closer. By gradually increasing the power of the prism, one will be found which brings the lines together, so that the picture will now be that of two dots over each other on one line. This prism is the measure of the insufficiency. Landolt estimates the amount of insufficiency of convergence by means of the metre angle and amplitude of convergence. For an account of the method I must refer the reader to his valuable work.* Maddox's Rod Test is an admirable method for ascertaining the condition of the muscular equili- brium of the eyeballs, and for estimating any exist- ing derangement of it. The apparent lengthening of a flame into a line of light, when looked at through a strong cylinder, is utilized 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 Fig. 163. The Refraction and Accommodation of the Eye," 1886, p. 501, 480 DISEASES OF THE EYE. Fig. 164. prisms, vitiate the result materially. A glass rod mounted in a circular metal disc, as in Fig, 164, may be used ; or a piano- cylinder with a radius of about 20 mm. ; or a piece of corrugated glass ; or a flat series of thin glass rods side by side. The best flame is that of a gas-jet turned low, at a distance of 5 mm. or 6 mm., and the appearance is improved by a piece of blue glass before the other eye, to equalize the illumination of the two images. The line of light is at right angles to the axis of the cylinder. If it pass through the flame the balance is perfect ; if not, the defect is measured by the deviating angle of the prism which is found to bring them together, or preferably, by a lithographed 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 verti- cal, it should be shaded from the light of the window. By placing the patient's head in different posi- tions, the diplopia can be measured in all parts of the motor field. Vertical and horizontal scales should, for this purpose, be fixed on the wall, with their zeroes coincid- ing at the position of the flame. For near-vision tests, a flame is too large. A scale should be used on a black background, with a small silvered hemisphere or bead fixed to its zero, to be a source of reflected light from the window or from a flame. This test is also very serviceable in overcoming the suppres- sion of the false image in old squints, and for discovering the latent paresis of an ocular muscle. Insufficiency of the internal recti is a common attendant upon myopia, and is probably congenital, like the myopia. It is also found with emmetropia, and even with hypermetropia. THE ORBITAL MUSCLES. 481 Concomitaut divergent strabismus is a further development of the same condition. Treatment. — In moderate degrees of myopia, the use of such concave glasses as will permit the patient to read at 35 cm. distance may relieve the asthenopic symptoms. Decentration of these glasses may give further aid. If the glasses be so set in the spectacle frame that their centres are on the outer side of the visual lines, the inner half of the glasses act as prisms with their bases inward (Chap. I, p. 2), and by them the rays are broken inward, i. e., toward the macula lutea in each eye, so that a slight divergence may take place without diplopia, etc. In this way the internal recti are relieved. Should the case be one demanding the use of convex glasses (hypermetropia, presbyopia), the decentration must be inward. A more perfect and accurate method is that of prescribing prisms, bases inward, to be worn for reading and other near work. These may be combined with concave or convex glasses, where such are indicated. The prism which is the measure of the insufficiency (see above) is divided between the two eyes. If it be 4°, a prism of 2° is placed, base inward, before each eye for near work. Very high prisms cannot be ordered, owing to the color effects they produce; and, in cases where they would be required, the insufficiency can be only partially corrected. Operative Treatment. — This consists in weakening the too strong external rectus by tenotomy. The danger of the method is, that convergent strabismus with homonymous diplopia for distant objects might result, unless the case be suitable for operation. Only those cases are suitable in which absolute divergent strabismus is present; or those in which, with a prism of not less than 10°, base inward, before one eye, the flame of a candle at 3 mm. distance is seen single, or if it be, perhaps, doubled for a moment, then becoming again single. When, with such a prism, single vision is present, the external rectus by an effort must have overcome the effect of the prism, and it is admissible to deprive the muscle of the power represented by that effort or prism. If diplopia be produced by a prism of 10^, 41 482 DISEASES OF THE EYE. the tenotomy is contraindicated, for the effect of the latter could not be modified to the slight power of abduction indicated by a weaker prism. A source of error in the ascertaining of this abduction prism which must be guarded against is, that the patient may suppress the image of one eye, and that his single vision may be merely due to the fact that he is seeing with the other alone. The higher the abduction prism, the more exten- sive may be the division of the subconjunctival tissue, etc., while with weak abduction the effect must be diminished by a con- junctival suture. Immediately after the operation there should be a certain amount of convergence, as shown by homonymous diplopia in the middle line for the flame of a candle at three mm. distance. This convergence, or diplopia, should not be greater than can be corrected by a prism of 10°. Moreover, if the candle be moved from the middle line 15° to the opposite side from the operated muscle (to the right if the left external rectus has been tenoto- mized), there should be no convergence (no diplopia), and a vertical prism before one eye should only cause double images placed directly over each other. If, by these experiments, it be shown that the operation has produced an excessive effect, the latter must be diminished by a suture drawing the lips of the conjunctival wound together, and including more or less con- junctiva, according to the excess to be corrected. Or, if a suture have already been applied, and the result be still in excess, it must be withdrawn, and a still more restricting suture inserted. In all these cases, convergence must necessarily be present when the candle is carried over to the side of the operated muscle ; but this disappears — except, perhaps, at the very most extreme position on that side— as also the convergence in the middle line, by reason of cicatricial contraction at the new insertion of the tendon ; always provided, that the indications for the opera- tion and its performance, as above set forth, have been accu- rately attended to. the orbital muscles. 483 Nystagmus. This term indicates an involuntary oscillation of the eyeballs from side to side (the most common form), in the vertical direc- tion, or rotary (caused by the oblique muscles). It is most commonly found with congenitally defective vision — microphthalmos, coloboma of the choroid, in albinos, etc. — but it may be acquired, and is often seen in those employed in coal mines. It occurs in about one-half the cases of disseminated sclerosis, and, as it is rarely met with in tabes or other chronic nervous disorders, it is here a symptom of diagnostic value. In the congenital cases it is probable that the absence of the stimulus which accurate retinal impressions afford interferes with the functional development of the coordinating centres for the orbital muscles. In coal mines, the very defective light, and the blackness of the surroundings, deprive the miners of any defined retinal impression, and hence their coordinating centres are apt to become deranged. But, as it is chiefly those who work in one constrained position on their sides, with eyes directed obliquely upward, who become affected, it seems likely,"^ that this unnatural and long-continued direction of the eyeballs is an im- portant factor in the production of the affection ; indeed, it is prob- ably to a great extent a professional cramp, like writers' cramp. Those patients in whom nystagmus is due to a congenital defect of vision, do not complain of oscillation of the objects they look at ; but individuals who become affected with it in later life are much troubled with that symptom, especially at the onset. Treatment. — In congenital cases which admit of improvement of vision, a cure, partial or complete, is sometimes brought about, when the vision improves. If strabismus be present, it should be cured, after which a diminution in the oscillations may result. In miners' nystagmus, the all important measure is a permanent relinquishment of mine work; and this is frequently followed by satisfactory results. "^Vide S. Snell, Brit Med. Jovrn., July 11th, 1891. CHAPTER XIX. DISEASES OF THE ORBIT. Orbital Cellulitis, or Inflammation of the Connective Tissue of the Orbit. — The Symptoms of this affection are: Erysipela- tous swelling of the lids, especially of the upper lid ; serous chemosis ; pain in the orbit, increased on pressure of the eyeball backward ; violent facial neuralgia ; exophthalmos, with impair- ment of the motions of the eye in every direction ; and high fever. Vision is not generally affected, but sometimes it is so from 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 tumor. This gradually increases in some one direction, the integument in that position becomes redder, fluctuation be- comes pronounced, 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 nor- mal state, as a rule, comes about; but, in some cases, complete atrophy of the optic nerve supervenes. Causes. — 1. Idiopathic (e. g., cold) ; 2. Traumatic (perforating injuries, foreign bodies) ; 3. Extension of inflammation from surrounding parts (erysipelas, diseased tooth, ethmoidal cells) ; 4. Metastasis (pyaemia, metria) ; 5. Sequelae of fevers (scarla- tina, typhoid, purulent meningitis). Treatment. — Locally, poultices or warm fomentations ; and, when pus has formed, its earliest possible evacuation, — by pre- ference from the conjunctival sac. The general constitutional treatment suitable to each case ireed not be discussed here. 484 THE ORBIT. 485 Periostitis of the Orbit. — Acute periostitis has many symp- toms in common with phlegmonous inflammation of the orbital connective tissue which generally accompanies it ; but may usually be distinguished from the latter inflammation occurring independently, by the fact, as first pointed out by the late Mr. John Hamilton, of Dublin,^ 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 eyeballs are not usually so swollen as in inflam- mation of the orbital tissues. Suppuration may take place, necrosis in consequence of detachment of the periosteum may come on, and communications with the neighboring cavities be formed. In secondary syphilis, or in later stages of the disease, a syphilitic gumma of the orbital wall may form. This is ac- companied by violent frontal neuralgia or headache, increasing at night. Proptosisf {~po, forward; -rwfTt?, falling), occurs with marked loss of motion of the eyeball in one or more direc- tions. This loss of motion is a very characteristic symptom, and serves to assist in the diagnosis between this affection and other orbital tumors. It is probably due to an extension of the inflammation to the connective tissue of the orbit, and to the muscles themselves. Again periostitis of a chronic form, and without tendency to suppuration, occurs most commonly in persons with a constitu- tional rheumatic tendency. It is accompanied by pain in and about the orbit, and there is increased tenderness on pressure of the eyeball backward. Exophthalmos, and all other outward signs, are usually wanting. The Prognosis depends much on the seat of the inflammation. If this be in the deep parts of the orbit, thickening of the peri- osteum may cause permanent protrusion of the eyeball ; exten- * Dublin Journal of Medical Sciences^ 1836. t Protrusion of the eyeball. 486 DISEASES OF THE EYE. sion of the inflammation of 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 periostitis may strike into the meninges of the brain. When the inflammation is near the margin of the orbit, early evacua- tion of pus, if it has formed, reduces the process within safe bounds ; and this position is one of less danger in respect of its surroundings. Causes. — Periostitis of the orbit may be caused by blows or other traumata, by extension from neighboring cavities, by syphilis, or rheumatism. Treatment. — Warm fomentations. Exit given to pus, if pos- sible. Constitutional measures. 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 of the bone. It is also seen in very late syphilis. A trauma is sometimes the immediate cause of its onset. It may attack any part of the orbital walls, its favorite seats being the margin above and to the outside, or below and to the outside. When it is seated deeply in the orbit, it often causes exophthalmos and pain. At the margin of the orbit it produces cedema and swelling of the eyelids with conjunctivitis, suppura- tion comes on, and the abscess finally opens through the integu- ment or conjunctiva. A fistula is apt to remain for a length of time, and, the skin being drawn 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. 169). Treatment. — The evacuation of purulent collections at the earliest possible moment — if deep in the orbit, by the careful introduction of a long bistoury — the insertion 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. Injuries of the Orbit. — Wounds of the soft parts in the supra- orbital region, involving the supra-orbital nerve, are believed THE ORBIT. 487 by some to be capable of producing a reflex amaurosis (p. 418), and many such cases have been recorded under the name of supra-orbital amaurosis. By the light of modern physiology and ophthalmology it is not probable, I might say not possible, that any such reflex could take place, and it seems likely that the blindness in those recorded cases was brought about in some other way, e.g., orbital periostitis, concomitant injury to the eyeball itself, facial erysipelas, intracranial lesions, and so on. Perforating injuries 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 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. I saw a case in which a bit of wood, f-inch long by 2-inch wide, lay unsuspected in the orbit for many weeks, without causing any marked displacement of the eyeball. 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. Tumors of the Orbit necessarily give rise to proptosis, and the motions of the eyeball are generally impaired. Vision often remains good until a very late period, unless, as rarely occurs, the optic nerve should early become involved in the growth ; but, ultimately, optic neuritis, or optic atrophy induces blind- ness. The upper lid, becoming wonderfully enlarged, protects the cornea from exposure and consequent ulceration, until, at last, the excessive protrusion of the eyeball no longer admits of this, and the cornea sloughs. When the tumor has attained a certain size, it may be felt by the tip of the finger passed into the orbit, and some idea of its consistency and mobility can be formed. 488 DISEASES OF THE EYE. Ill every case, the history, the rapidity of growth, and the general condition of the patient are important items for con- sideration. Cysts. — Dermoid cysts are amongst those most frequently found. They 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 dis- tinct fluctuation in the protruding part can be felt. The growth of the cyst is unaccompanied by pain or other inconvenience. The contents are generally either serous or honey-like, and, occasionally, hairs and other epidermic formations have been found in them. A mucocele originating in the frontal or in the ethmoid sinus may absorb the orbital wall, protrude into the orbit, and give rise to all the signs and symptoms of a true orbital tumor. Treatment. — The cyst should be freely opened at the most prominent point, evacuated by gentle pressure backward of the eyeball, and the sac syringed out two or three times daily with an antiseptic solution, until all discharge has ceased. The opening will then close, while the eyeball will already have returned to its place. If the contents of the cyst are solid, or nearly so, it becomes necessary to extirpate it in toto. To do this, as in other tumors also, a horizontal incision must 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 upward. With hooks or forceps, and scalpel or scissors, the cyst wall must then be carefully separated from all adhesions. Exostoses occur as the result of inflammation of the bone and of periostitis, and are usually of the kind known as ivory exos- toses. They spring most commonly from the ethmoid, or from the frontal bone. Their surface is tuberous. Their growth is extremely slow, in many instances commencing in infancy and lasting into advanced life. THE ORBIT. 489 Operative iuterference in cases of exostosis of the orbit is only justifiable when the tumor does not grow from the roof of the orbit, and where there is reason to think 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. Beyond destruction of the eyeball, there is no danger associated with these tumors, even if their growth take an intracranial direction ; but they cause serious disfigurement and much pain. Carcinoma and Sarcoma. — The first of these tumors takes its origin in some neighboring cavity and grows into the orbit, or it may start from the orbital walls, or from the retro bulbar connective tissue. Sarcoma may originate in many diflferent positions, most frequently, perhaps, in the periosteum, and in the connective tissue about the lachrymal gland. These malig- nant tumors, after destruction of the eyeball by pressure, or by phthisis following ulceration of the cornea, attack the bony walls of the orbit and its surroundings. Many forms of sar- coma, however, are non-malignant. The early extirpation of the tumor affords, in general, the only prospect of saving the patient's life. Pulsating Exophthalmos. — This title includes a great variety of vascular tumors, the majority of them having their origin within the cranium, while the remainder are truly orbital. Symptoms common to all these are : Proptosis ; the presence of peculiar bruits which can be heard over the orbit, and usually also over a more or less extensive portion of the skull ; and pulsation, apparent in the eyeball, or at some point of the orbital aperture. The last symptom may occasionally be absent during the whole, or part, of the progress of the case. The intracranial vascular tumors with which we are most likely to have to deal are : Aneurism of the ophthalmic artery at its point of origin from the internal carotid; aneurism of the latter vessel; and, most commonly, arterio-venous aneurism from com- munication of the internal carotid with the cavernous sinus — this latter of traumatic origin. In the orbit the following 490 DISEASES OF THE EYE. occur: True aueurism of any of the arterial branches; diffused or circumscribed traumatic aneurism; arterio-venous aneurism, of traumatic origin; aneurism per anastomosis; and teliangiectic tumors. Hemorrhage 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 produced cure in some cases. Diseases of Neighboring Cavities are sometimes liable to encroach upon the orbital space and to displace the eyeball. The frontal sinus and the antrum of Highmore are the cavities which chiefly come under notice here, but disease of the eth- moidal and sphenoidal sinus does so more rarely. The condition in these cases is, as a rule, retention of normal secretion from obstruction of the outlet of the cavity, or else empyema. The most common initial cause is catarrh of the nasal mucous membrane extending into these cavities, or a blow which fractures the bone in such a way as to occlude the ways of exit. Polypi sometimes grow in these cavities and distend them. When a collection of fluid occurs in the frontal sinus, or in the antrum, it is usually present for a long time before the orbital cavity is invaded by bulging of its corresponding wall, and this is accompanied, or preceded, by a swelling in the fore- head or cheek, respectively. Finally, the orbital wall is apt to become perforated. Then, in the case of a frontal empyema, an elastic swelling appears at the upper and inner angle of the orbit, near the pulley for the tendon of the superior oblique ; while, in the case of the antrum, the tumefaction appears between the eyeball and the inferior orbital margin. The eyeball in each instance is more or less displaced in the opposite direction and forward. As there is no frontal sinus in children under eleven years of age, frontal empyema cannot occur in young children. Prior to perforation of the orbital wall the only Treatment that can be adopted is the formation, by means of a gouge, of an THE ORBIT. 491 opening into the cavity, either through the orbit or nostril in the case of frontal disease, or through the orbit or cheek in the case of disease of the antrum. After perforation, evacuation of the fluid must of course be made where it points in the orbit. When the fluid has been evacuated, the cavity must be washed out daily with sublimate or astringent lotions, to bring about a healthy state of the lining mucous membrane and to arrest the discharge. But the complete cure of these cases is often an extremely tedious matter, and may extend over many months. Empyema of the Ethmoidal Cells presents itself as an orbital abscess, pointing at the upper and inner angle of the orbit, causing displacement of the eyeball forward, outward, and downward. It is not possible to diagnose with certainty the place of origin of the abscess, unless some of the purulent dis- charge come through the nostril. After the abscess has been opened lotions syringed into the opening may flow out by the nose. Empyema of the Sphenoidal Sinus is extremely rare, and is in most instances difficult or impossible of diagnosis ; for, if it give rise to exophthalmos, there is nothing to distinguish the latter from protrusion of the eyeball due to many other causes. Ethmoidal and Sphenoidal Empyema may produce blindness by pressure on the optic nerve, or by setting up orbital cellulitis. Hernia Cerebri, either in the form of meningocele or of en- cephalocele, 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 transparent, pulsating congenital tumor. Pressure causes it to disappear, but gives rise, at the same time, to symptoms of cerebral irritation, or pressure. A congenital tumor in the upper inner angle of the orbit must always be regarded with suspicion, lest it be a cerebral hernia, even though it do not pulsate, or on pressure cause cere- bral symptoms. In the large cerebral hernia death in the first few days of life is, we know, the rule. 492 DISEASES OF THE EYE. Exophthalmic Goitre — (Graves' Disease, Basedow's Disease). Symptoms. — The three cardinal symptoms of this disease are : Increased rapidity of the heart's action, which may reach two hundred beats per minute ; tumefaction of the thyroid gland, and exophthalmos. 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, with outbursts of sweating and diarrhoea. A venous murmur may be heard in the neck. And, in females, there is very commonly irregularity, or suppression of menstruation. The disease has been observed at all ages, but is most common in early adult life. Von Graefe'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 downward, 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 only in an imperfect manner ; and, conse- quently, when the patient looks down, a zone of sclerotic be- comes visible between the margin of the lid and the cornea. This symptom is often present prior to any exophthalmos, and hence its great diagnostic value. It may also continue after the latter disappears — although it is perhaps more common for it to disappear 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 by von Graefe to be. 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 is also very constant. It is incompleteness, and diminished frequency, of the act of involuntary nictitation. This act occurs sometimes only once in a minute, or several rapid nictitations take place, and then a lengthened pause. The THE ORBIT. 493 nictitation each time is incomplete, the margins of the lids not being brought together. The result of this may be that the lower third of the cornea becomes covered with pannus vessels, owing to the constant exposure ; for even during sleep the eye- lids remain partially open. Dalrymple's Sign consists in an abnormal widening of the palpebral aperture, due to retraction of the upper eyelid. It is this gaping of the eyelids which gives the characteristic staring aspect to the patient. This sign is often erroneously at- tributed to Stellwag, or is included in his sign. The error is due to the fact that in the same paper * in which Stellwag first drew attention to what is above described as his sign, he dis- cussed this other previously observed sign. According to White Cooper t it was Dalrymple who first pointed out the latter. J Probably each of these " signs " is due to the one cause sug- gested by Sharkey, § namely, loss of power in the orbicularis, rather than over-action of the levator. Otto Becker states that, in a majority of the cases, spontaneous pulsation may be seen in the retinal arteries, but I have only found it sometimes. The vision — unless when corneal complica- tions supervene — and condition of the pupil are unaffected by the disease. 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, although Graves' Disease is more common * Wiener Med. Jahrbucher, xvii, p. 25, 1869. See also Klin. Monatshl. fur Augenheilkunde, 1869, p. 216, and "Graefe und Saemisch's Hand- buch," vi, pp. 955 and 956. t The Lancet, May 26, 1849, p. 553. t Other conditions which produce widening of the palpebral aperture, or " Staring Eye," are: 1. Orbital Tumor (mechanically). 2. Stimu- lation of the Cervical Sympathetic. 3. Cocaine (in slight degree, prob- ably by reason of 2. — Jessop). 4. Women after childbirth (hysteria). 5. In tetanus (spasm of occipito-frontalis). 6. In complete amaurosis. ^ Trans. Ophth. Soc, vol. xi, p. 204. 494 DISEASES OF THE EYE. in women. The exposure of the eye and dryness of the cornea are the chief causes of ulceration, when it occurs ; but Sattler inclines to the belief that it is also largely due to paralysis of the nervous supply of the cornea. The patients are often hysterical ; and even marked psychical disturbances have been noted, such as a peculiar and unnatural gayety, 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. Trousseau's Celebrated Macula is often well marked. The Progress of the Disease is, as a rule, very chronic, extend- ing over months or years, but liable to fluctuations in the inten- sity 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 lengthened period and many fluctuations, the symptoms usually slowly disappear. Occasionally, a slight permanent swelling 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, hemorrhage from the bowels, or gangrene of the extremities. Causes. — Ansemia and chlorosis 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 con- comitant 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, however, 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 THE ORBIT. 495 tissue, and even cystic degeneration. The Exophthalmos is due to hypersemia of the retro-bulbar orbital tissues, as is demon- strated 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 post-mortem, but is, doubtless, secondary to the hyper[:emia. The Theory until of late widely held as to the Nature of the Disease represents it as a lesion of the cervical sympathetic, which causes paralysis of the vaso-motor nerves, and consequent goitre, exophthalmos, and pulsation and dilatation of the caro- tids and retinal arteries ; while it causes excited cardiac action by reason of a permanent irritation of the excito-motor nerves of the heart, which also run in the cervical sympathetic. Here the difficulty arises, that two of the chief symptoms are attempted to be explained as the result of paralysis, while the third is said to be due to excitation. The absence, as a rule, of a pupillary symptom is a strong argument against a lesion of the sympa- thetic. That a state of continuous irritation of the sympathetic should exist is improbable, and is without proved physiological analogy. With regard to paralysis of the sympathetic causing the goitre and exophthalmos, it is doubtful whether it could do so; for experimental division' of the sympathetic has not pro- duced these symptoms in animals, nor have they resulted in clinical cases of paralysis of that nerve in man, although the pupillary symptoms have been marked. Post-mortem exami- nation has, no doubt, in a very few instances, revealed alter- ations in the cervical sympathetic, but they were of an inconstant nature, and were wholly wanting in the vast majority of cases which have been microscopically examined. These considerations tend to discredit the sympathetic theory. Professor Sattler, of Leipzig,* has advanced a theory which is worthy of consideration. He assumes a lesion of those cir- cumscribed portions of the vaso-motor centre in the brain which preside over the vaso-motor nerves of the thyroid gland * " Graefe and Si^misch's Handbuch,'' vol. vi, p. 084, tt aeq. 496 DISEASES OP THE EYE. and of the intraorbital tissue, and believes that the great con- stancy with which enlargement of the thyroid and exophthal- mos are present indicates an intimate local relation of these two portions. He attributes the cardiac symptoms to a lesion of the cardio-inhibitory centre for the pneumogastric. He also regards Graefe's symptom as due to a central lesion ; one, namely, ot the co-ordinating centre for the associated motions of the lids and eyeball ; while Stellwag's symptom, he believes, as does Stellwag himself, to be due to a lesion of the reflex centres, which are excited by stimuli from the retina and from the sensi- tive nerves of the cornea and conjunctiva. Battler's theory de- rives important support from the experiments of Filehne.* When this observer divided the restiform bodies in their upper quarter, although the incision was not carried so deep as to wound the roots of the vagus, yet the functions of the latter nerve became impaired, exophthalmos was produced, and, al- though the thyroid did not swell, there was vaso-motor paralysis in the ears, thyroid, and anterior part of the neck. Hence, Filehne concludes : that Graves' Disease may be produced by paralysis of certain nerve-regions controlled by the medulla ob- longata, and that the points traversed in common by the nerve- paths concerned are the restiform bodies; that the exophthalmos and goitre depend on dilatation of the blood-vessels ; and that the increased heart's action is due to diminution or abolition of tone in the pneumogastric. Post mortem examinations in the human subject are necessary to establish Filehne's theory, but he points out that negative results from some of these would not be fatal to his theory, as the occurrence of functional affec- tions of the central nervous system is admitted. Dr. William A. Fitzgerald f has pointed out that exophthalmic goitre is frequently complicated by symptoms which are clearly due to a ^"Zur Pathogenese der Basedow' schen Krankheit," Sitzungsher. d. Phys. Med. Sac. zu Erlangen, July 14, 1879, p. 177. See also " Graefe und Soemisch's Handbuch," vol. vi, p. 1001. t" Theory of a Central Lesion in Exophthalmic Goitre," Dublin Journal Med. Sc, March and April, 1883. THE ORBIT. 497 central lesioD, such as symmetrical paralysis of the external recti, paralysis of the associated motions of the eyes, and glyco- suria. Hale White has recorded * a case of Graves' Disease in which, after death, the only lesions were small hemorrhages in the floor of the fourth ventricle. A very able explanation of the marked preference shown by the symptoms for the right side of the body is given by Dr. W. A. Fitzgerald {loc. cit). Bilateral symmetry (double exophthal- mos and swelling of each half of the thyroid), although not uncommon, is not always present, especially in the early stages ; and when want of symmetry exists the preponderance of the symptoms is on the right side — the right eye protruded and the right lobe of the thyroid enlarged. It has occurred to him that the extreme constancy of the cardiac symptoms affords a clue to the problem of this preference, for he believes that it, too, is a right-sided symptom, as it is more than probable that it is the right vagus which is chiefly concerned in the inhibition of the heart, and that the left has but little power of the kind. Ar- loing and Tripier's experiments,! and those of Masoin J and of Meyer, § show this ; and several cases are on record in which ir- ritation of the right pneumogastric in man caused marked cardiac inhibition. Fitzgerald thinks, also, that the mode of develop- ment of the heart affords an explanation of the supply of that organ by the right rather than by the left vagus; for, soon after its appearance in the embryo, it projects to the right side, where it comes in relationship with the corresponding vagus. Treatment — A principal part of this consists in the careful regulation of the patient's general health and functions. Free- dom from mental anxiety and excitement, regular hours, moderate exercise, and change of air are the most important items. * Brit. Med. Journ., March 30, 1889. t Archives de Physiologie, tome v, p. 166, 1873. % Bull, de V Acad. Roy. de Med. de Belg., tome vi, 3me serie, p. 4. § "Das Hemmungsnervensystem des Herzens," p. 61, 1869. 42 498 DISEASES OF THE EYE. The fluctuations which occur in the intensity of the symptoms render it difficult to arrive at definite conclusions with 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, but in severe cases it has the opposite effect. Quinine in moderate doses has been employed with benefit in some cases. Trousseau recommended digitalis in large doses, but its eflfect 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 symptoms are sometimes aggravated, and it is doubtful whether they are ever relieved by it. Mr. Hulke * speaks highly of aconite, and Dr. Samuel Wilks f has no doubt as to the value of 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 with ice applied to the head, heart, and goitre. The sympathetic theory has induced the trial of a gal- vanic treatment of the cervical sympathetic. Dr. GauthierJ recommends antipyrin before everything else. Lemke, of Hamburg, § in two cases removed one-half of the en- larged thyroid, with the result of curing the exophthalmos and the excited heart's action, while the other half of the thyroid became spontaneously reduced to normal size. The great number of remedies which have been proposed for it demonstrate the incurable nature of most cases of this disease. In cases where the exophthalmos is so great that the cornea is exposed, even during sleep, it is desirable to perform tarsorraphy (p. 148) ; 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. * Trans. Ophthal. Soc, vol. vi, p. 34. t Ibid., vol. vi, p. 56. t Rev. cle M(^d ,\890, p. 409. 3 Deutsche Med. Wochenschr., Jan. 8, 1891. APPENDIX I HOLMGREN'S METHOD FOR TESTING THE COLOR-SENSE. For the purposes of this method, a selection of Berlin worsteds is made, including red, orange, yellow, yellow-green, pure green, blue- green, blue, violet, purple, pink, brown, gray ; several shades of each color being present, and at least five gradations of each tint, from the deepest to the lightest. Green and gray, several kinds each of pink, blue, and violet, and the pale gray shades of brown, yellow, red, and pink, must be well represented. But no two samples are to be of precisely the same shade of the same color. This large number of colors and shades is used because the color-blind person escapes detection with more difficulty, and the diagnosis therefore is all the more certainly made the greater the variety of colors. The normal- eyed individual readily selects the right ones from the mass ; whilst the color-blind person, although the right ones are directly before him, picks out wrong ones, thereby disclosing the character of his defect. The test-color with which Holmgren invariably begins his examination is a pale pure green, because green is the whitest of the spectral colors, and, consequently, the one in which the presence of color is most diffi- cult to recognize — the one, in short, most easily mistaken for gray (= no color). Furthermore, as we all experience the most difficulty in deciding whether there be any " color " at all present in the very deepest shades (nearly black), and in the very palest shades (nearly white), it was plainly either a very dark or a very pale shade of green that should be employed, and Holmgren's experience made him decide for the pale shade, as providing the most delicate test. As a test for the diagnosis of the particular kind of color-blindness, Holmgren recommends a purple (deep pink) sample — that is, the whole group of colors in which red (orange) and blue (violet) are combined in nearly equal proportions, or at least in such proportions that no one of them sufficiently preponderates over the others, to the normal sense, so as to give its name to the combination. Purple is of especial importance in the examination of the color-blind, for the reason that it forms a 499 500 DISEASES OF THE EYE. combination of two fundanaental colors (red and blue) — the two extreme colors — which are never confounded with each other. The Method of Examination and of Diagnosis is as follows: The worsteds are placed in a pile on a table in broad daylight. The test skein is taken from the pile and laid at a short distance from it, so as not to be confounded with the other skeins during the trial, and the person examined is then requested to select other ekeins most resem- bling this in color and to place them by the side of the sample. It is necessary he should have clearly understood what is required of him; namely, that he should search the pile for the skeins making an im- pression on his chromatic sense similar to that made by the sample, and independently of any name he may give the color. Indeed, it is not desirable that he should be asked to name the colors, and he should be discouraged from doing so, The examiner should explain that resem- blance in every respect is not necessary ; that no two specimens are just alike ; that the only question is the resemblance of color ; and that, consequently, he must endeavor to find something lighter and darker of the same color. If the person examined cannot understand this verbal explanation the examiner must resort to action. He must himself make the trial by searching with his own hands for the skeins, thereby showing what is meant by a shade, and afterward restoring the whole to the pile, except the sample skein. Or, when a large number of persons have to be examined together, it will be more rapid to begin at once with such a demonstration before the assemblage. There is no loss of security in this, for no one with defective chromatic sense finds the correct skeins in the pile any the more easily from the fact of having a moment before seen some one else looking for and arranging them. On the card which is attached to the inside of the back cover of this book there are two classes of wool-samples. 1. The Test Samples, which are placed horizontally. 2. The Colors of Confusion, — that is, those which the color-blind person selects from the heap of wools, because he confuses them with the color of the sample, — and these are arranged vertically under their respective test-samples. The test is conducted as follows: Test I. The green sample is presented. This sample, as already explained, should be of the palest shade of very pure green, which is neither yellow-green nor blue-green to the normal eye, but fairly intermediate between the two. The examination must be continued until the person examined has selected all the other skeins of the same color, or else, with these or separately, one or several skeins of the class corresponding to the "colors of confusion" (1 to 5), until he has sufficiently proved by his manner of doing it, that he can easily and unerringly distinguish the confusion APPENDIX I. 501 colors, or until he has given proof of unmistakable difficulty in accomplishing his task. He who places beside the sample one of the colors of confusion (1 to 5), that is to say, finds that it resembles the test sample, is color-blind. He who, without being quite guilty of this confusion, evinces a manifest disposition to do so, has a feeble chromatic sense. If we want to know the kind and degree of the color-blindness which the failure to perform Test I shows to be present, we must proceed to — Test Ha. A purple skein is shown to the person being examined. The trial must be continued until he has selected all, or the greater part of, the skeins of the same color, or else, simultaneously or separately, one or several skeins of "confusion" (6 to 9). He who confuses, selects either the light or deep shades of blue and violet, especially the deep shades (6 and 7), or the light or deep shades of one kind of green or gray, inclining to blue (8 and 9). 1. He who is color- blind by Test I, and who, upon Test II a, selects only purple skeins, is termed "incompletely color-blind." 2. He who, in Test 7/ a, selects with purple only blue and violet, or one of them, is " completely red- blind." 3. He who, in Test Ha, selects with purple only green and gray, or one of them, is " completely green-blind." The red blind never selects the colors taken by the green-blind, or vice versa. Often the green-blind places a violet or blue skein beside the green, but only the brightest shades of these colors. This does not influence the diagnosis. The examination may end here, and the diagnosis be regarded as settled. But to convince railway employers, and shipowners, and their employes, a still further trial may be made. It only serves to corroborate the diagnosis. Test lib. — The red skein is presented. It is necessary to have a vivid red color, like the red flag used as signals on railways. This test, which is applied only to those either "completely red-blind" or "completely green-blind," should be continued until the person ex- amined has placed beside the specimen all the skeins belonging to this shade, or the greater part of them, or else, separately, one or several "colors of confusion" (10 to 13). The red-blind then chooses, besides the red, green and brown shades, which (10 and 11) to the normal sense seem darker than red. On the other hand, the green blind selects opposite shades, which appear lighter than red (12 and 13). Every case of complete color-blindness discovered does not always make the precise mistakes just mentioned with Test lib. These exceptions are either persons with comparatively inferior degrees of complete color-blind- ness, or color-blind persons who have been exercised in the colors of 502 DISEASES OF THE EYE. signals, and who try not to be discovered. Tiiey usually, but not always, confound at least green and brown. Total color-blindness is extremely rare, but such a case would be recognized by a confusion of every color having the same intensity of light. Violet-blindness will be recognized by a genuine confusion of purple, red, and orange in Test II h. I have described Holmgren's Method at some length, as it is probable that in the near future (see footnote f; p. 506) more importance will be attached by the Board of Trade to color-blindness in sailors and in railway employes than has hitherto been the case. This method has been specially arranged for the examination of persons in these employ- ments, and has had, for many years, an extensive trial in various countries. The test is equally suited to the examination of acquired and of congenital color-blindness. If further information on the subject be desired, the reader should consult Professor Holmgren's original monograph, " De la Cecite des Couleurs," Stockholm, 1877, or Dr. Joy Jeffries' "Color-Blindness," Boston, 1879. APPENDIX II. REGULATIONS AS TO DEFECTS OF VISION WHICH DIS- QUALIFY CANDIDATES FOR ADMISSION INTO THE CIVIL, NAVAL, AND MILITARY GOVERNMENT SER- VICES, THE ROYAL IRISH CONSTABULARY, AND THE MERCANTILE MARINE. By an army circular issued by the War Office on September 1, 1887. and which remains in force : — Candidates for Commissions in the Army are required to possess the following visual powers. These regulations apply to all branches of service, including the Medical Department. Letters and numbers corresponding to Snellen's Metrical Test- Types (Edition 1885) will be used for testing the standard of vision. If a candidate's vision, measured by Snellen's test-types, be such that he can read the types numbered D = 6 at 6 metres, or 20 English feet, and the types numbered D :=^ 0.6 at any distance selected by himself, with each eye separately, and without glasses, he will be considered fit. If a candidate cannot read with each eye separately, without glasses, APPENDIX II. 503 Snellen's types marked D = 36 at a distance of 6 metres, or 20 English feet, i. e., if he do not possess one-sixth of Snellen's standard of normal acuteness of vision, although he may be able to read the types D = 0.6 at some distance with each eye, he will be considered unfit. If a candidate can read with each eye separately Snellen's types num- bered D =; 36 at a distance of 6 metres, or 20 English feet, without glasses, but cannot read them beyond that distance, i.e., if he just pos- sesses one-sixth of normal acuteness of vision, and his visual deficiency is due to faulty refraction, he may be passed as fit, provided that, with the aid of correcting glasses, he can read Snellen's type D =: 6 at 6 metres, or 20 English feet, with one eye, and at least Snellen's types D = 12 at 6 metres, or 20 English feet, with the other eye ; and, at the same time, can read Snellen's type marked D = 08 with one or both eyes, without the aid of glasses, at any distance the candidate may select. [i. e. As a minimum, a candidate must have with each eye separately V = 3^ without glasses ; as well as V = 4 with one eye, and V = ^% with the other eye, with glasses.] Squint, inability to distinguish the principal colors, or any morbid con- dition, subject to the risk of aggravation or recurrence in either eye, will cause the rejection of a candidate. The following are taken from Sir Joseph Fayrer's " Regulations as to Defects of Vision, etc."* The Royal Navy. — 1. A candidate is disqualified unless both eyes are emmetropic. The candidate's acuteness of vision and range of accom- modation must be perfect. 2. A candidate is disqualified by any imperfection of his color-sense. [The two foregoing rules do not apply to the Medical Department.] 3. Strabismus, or any defective action of the exterior muscles of the eyeball, disqualifies a candidate for the Royal Navy. The Home Civil Service, — With reference to the Home Civil Service, the Commissioners refer each case to "a competent medical adviser, leaving him to apply whatever tests he may deem suitable, and whatever standard the particular situation may require." The Indian Civil Service {Covenanted and Uncovenanted).—!. A candi- date may be admitted into the Civil Service 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 f in one eye and | 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 do not * Second Edition, J. A. Churchill, 18S7. 504 DISEASES OF THE EYE. exceed 2.5 D. and no active morbid changes of choroid 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 /v, and in such a case the acuteness of vision in the better eye must equal f , with or without glasses. 4. Paralysis of one or more of the exterior muscles of the eyeball dis- qualifies a candidate for the Indian Civil Service. In the case of a candi- date said to have been cured of strabismus by operation, but without restoration of binocular vision, if with correcting glasses the vision reach the above standard (1), and if the movement of each eye be good, the candidate may be passed. The same rule applies to the case of unequal ametropia without binocular vision, both eyes having full acuteness of vision with glasses and good movement. The Indian Medical Service. — 1. A candidate may be admitted into the Indian Medical Service if myopic to the extent of 5 D., provided that with correcting lenses his acuteness of vision in one eye equal ^^ and in the other f , there being no morbid changes in the fundus of the eyes. Cases of myopia, however, with a posterior staphyloma, may be admitted into the service, provided the ametropia in either eye do not exceed 2.5 D., the acuteness of vision with correcting glasses being equal to the above standard, and no active morbid changes of choroid or retina being present. 2. Myopic astigmatism does not disqualify a candidate for the service, provided the combined spherical or cylindrical glasses required to correct the ametropia do not exceed —5 D. ; the acuteness of vision in one eye when so corrected being equal to y^o , and in the other eye f ; the accom- modation being normal with the correcting glasses, and no progressive morbid changes of the choroid or retina being present. 3. A candidate having total hypermetropia not exceeding 5 D. is not disqualified for the service, provided the sight in one eye (when under the effect of atropine) equal j^o, and in the other f , with + 5 D. or any lower power. 4. Hypermetropic astigmatism does not disqualify a candidate for the service, provided the combined lens required to correct the total hyper- metropia do not exceed 5 D. The acuteness of vision in one eye must equal f^ ^^^ i° ^^e other |, with or without the correcting glass. 5. A candidate may be accepted with a faint nebula of one cornea, reducing the vision to j%, provided the eye in other respects be healthy. In such a case the better eye must be emmetropic and possess normal vision. Defects of vision arising from pathological or other changes in APPENDIX 11. 505 the eye which are not referred to in the above rules may exclude a can- didate for admission into the Indian Medical Service. 6. A candidate is disqualified if he cannot distinguish the principal colors — red, green, violet or blue, yellow, and their various shades (Dig- chromatopsia). 7. Paralysis of one or more of the exterior muscles of the eyeball dis- qualifies a candidate for the Indian Medical Service. The Indian Marine Service {Including Engineers and Firemen). — 1. A candidate is disqualified if he have an error of refraction in one or both eyes which is not neutralized by a concave or by a convex 1 D. lens, or some lower power. 2. A candidate is disqualified if he cannot distinguish the primary colors and their various shades — red, green, violet or blue, and yellow. 3. Strabismus, or any defective action of the exterior muscles of the eyeball, disqualifies a candidate for the Marine Service. Royal Irish Constabulary. — Candidates for cadetships in the Royal Irish Constabulary, and recruits, must be able to read with each eye separately, and without glasses, Snellen's metrical test types (Edition 1882) 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 colors, 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.* — The Board of Trade does not as yet, although it probably very soon will (see footnote, p. 506), require a boy on joining the Merchant Service to pass any visual test. It is, how- ever, open to any person about to serve to submit himself to the Board of Trade tests for color-blindness. On wishing to become an officer (second mate), the sailor's color- vision is tested, f The tests are as follows : Test I. Colored cards. The candidate is required to select from the whole number of cards any one or more of a color named by the examiner. The candidate is shown a particular card, and asked to name its color. The candidate is required to place together all the cards of one color. Test 11. Colored glasses. The test is made in a dark room, and a lighted lamp or candle is placed behind the glass. Attention is especially directed to the candidate's ability to distinguish the red from the green glass. Test III. In some cases in which the examiner decides that the candidate has failed, and in * For the information contained in this section I am indebted to Mr. Bickerton, Liverpool. t Board of Trade Report upon the Tests for Color-blindness, 1885. 43 506 DISEASES OF THE EYE. which the latter holds a contrary opinion, as well as in cases which may raise a doubt in the examiner's mind, the facts are reported to the Department, and the applicant is re-tested by means of a modification of Holmgren's Test. The candidate for his officer's certificate is not tested as to his refraction, or acuteness of vision, except that "A person who has lost the sight of one eye cannot be permitted to be examined for a certificate of competency either for Foreign or Home Trade. If he already hold a certificate, he cannot be examined for a certificate of a higher grade." * In view of the fact that a sailor, after having spent some years at sea, may find himself disqualified by color-blindness for his mate's certificate, it is advisable that all boys should seek the Board of Trade's Color-Test Certificate before adopting the sea as their calling in life. It is evident that the visual tests required by the Board of Trade are imperfect and insufficient, and it is to be hoped that measures will soon be taken to make them what they ought to be.f * Board of Trade Circular, Xo. 259, February, 1885. f In the autumn of 1890 a Committee of the Royal Society was appointed to investigate the subject of color-blindness from a practical point of view. In May, 1892, it issued its Report, in which it recommends the systematic examination of railway men and sailors of the Mercantile Marine as regards their color-sense, and also Holmgren's Method as being the simplest and most efficient test. ^^Oo / % 'a, ^ % "U « vertical +jq„ INDEX Abscess of the Cornea, 196, 205 Accommodation, amplitude of, 11 ; anomalies of, 49 ; cramp of, 28, 31, 37, 55 ; and convergence, con- nection between, 12; mechanism of, 10 ; normal, 9 ; paralysis of, 53; relative, 12; relative ampli- tude of, 13 ; voluntary relaxation of the, 59 Accommodative asthenopia, 30, 31, 55, 82, 261 Acuteness of vision, the, 18 Adenoma of the eyelid, 141 Adaptation of the retina, 16 foot- note, 419 Advancement, operation of, for strabismus, 474 Albinismus, 260 Albuminuria, 366, 382, 394 Albuminuric retinitis, 366, 368, 389, 394 Alexia, 415 Amaurosis, 407; pretended, 420; quinine, 373 ; spinal, 401 ; supra- orbital, 418, 487 ; temporary, after blepharospasm, 126 Amblyopia, 407 ; alcoholic, 282, 395 ; central, 395 ; due to central lesions, 407 ; congenital, 317, 417, 460, 483 Amblyopia ex anopsia, 458 ; glyco- suric, 404 ; from hemorrhage (haematemesis, etc.); 405 ; hyste- rical, 418 ; from injury to supra- orbital nerve, 418, 587 ; reflex, 418, 687 ; in strabismus, 459 ; tobacco, 281, 395; toxic, 395; ursemic, 420 Ametropia, 25 Amplitude of accommodation, 11 ; in hypermetropia, 28 ; in myopia, 34 ; in presbyopia, 49 Amplitude of convergence, 13, 479 Amyloid degeneration of the con- junctiva, 111 Anaemia, 367, 386 progressive pernicious, 367 Aneurism of central retinal artery, 283 Angle alpha, 14 gamma, 14, 28, 35 in hypermetropia, 28 in myopia, 35 the metre, 13, 479 of strabismus, 465 the visual, 19 Aniridia, 242, 245 Anisometropia, 49 Ankyloblepharon, 170 Aphakia, 352 Aphasia, 413, 414 Apoplexy, cerebral, 280 of pons Varolii, 282 of retina, 367 Arcus senilis, 224 Argyll- Robertson's operation for ectropium, 166 pupil, 281 Argyrosis, 85 Arlt-Jaesche operation for trichi- asis, 154 Arlt's operation for ectropium, 169 Arthritis, gonorrhoeal, 107, 233 Asthenopia, 86, 90 ; accommoda- tive, 30, 31, 55 82; muscular, 477 ; neurasthenic, 385 ; retinal, 385, 459 Astigmatism, 25, 39 ; after cataract operations, 353 ; estimation of degree of, 45 ; irregular, 49, 217, 507 508 DISEASES OF THE EYE. 342, 344 ; lental, 48 ; ophthalmo- scopic diagnosis of, 44, 67, 74 ; retinoscopy in, 74; spectacles in, 45 ; symptoms of, 42 Atheroma, general, 366, 367, 382, 384 Atrophy, progressive muscular, 282 Atropine, 68, 87, 132, 189. 193, 194, 196, 209, 231, 237, 279, 304, 306, 315 poisoning, 238, 279 Bader's operation for conical cor- nea, 218 Berlin's operation for entropium, 162 Binocular vision, 468 footnote Bisulphide of carbon, amblyopia from, 397 Black eye, 172 Blennorrhoea of the conjunctiva, 99, 194 of the lachrymal sac, 175 neonatorum, 99 prophylaxis of, 101 Blepharitis, intermarginal, 83 ; marginal, 83, 135, 174, 180; squamosa, 135 ; ulcerosa, 135, 152 Blepharophimosis, 151 Blepharoptosis, 141 Blepharospasm, 126, 141 Blind spot. The, 24 Blow on eye, 54, 228, 240, 321, 322, 352, 356, 377, 387, 403 Bowman's operation for conical cornea, 219 Brain, localization of disease in the, 147, 412, 415, 416, 417, 446, 449 Breast, cancer of the, 258 Broca's lobe, lesion at, 417 Bronchitis, 254 Bulbar paralysis, 54 Buphthalmos, 308 Canaliculus, obstruction of the, 175 Canthoplasty, 98, 151 Capsule, Lesion of the internal, 412, 414 Capsulotomy, 326, 349 Carcinoma of the choroid, 258 of the orbit, 489 of the breast, 258 Cardiac disease, 366, 367, 382, 384 Caries of nasal bones, 181 Cataract, 35, 249, 252, 262, 309 adherent (or accreta), 320 anterior polar, or pyramidal, 107, 318 artificial ripening of, 315 black, 313 calcareous, 320 capsular, 320 central capsular, 107 central lental, 228 complete, 309 complete, of young people, 317 congenital, 251, 317 diabetic, 317 discission for, 346 extraction of, without iridec- tomy, 343 flap operation for, 343 fusiform, 319 von Graefe's operation for, 330 linear operation for, 325 morgagnian, 312 operations for, 323 partial, 317 posterior polar, 319 ripeness of, 311 secondary, 319, 349 senile, 309 spectacles after extraction of, 353 suction operation for, 349 symptoms of, 313 three millimetre flap operation for, 330 traumatic, 320 treatment of, 322 zonular, or lamellar, 317 Catarrh, conjunctival, 83 spring, 87 Cautery, the actual, 190, 195, 197, 198, 206, 219, 342 Cavernous sinus, thrombosis of the, 283 Cerebellum, tumor of the, 390 footnote, 452 Cerebral abscess, 390, 415; em- INDEX. 509 bolism, 280; disease, 142, 153, 446, 449; localization, 147, 412, 449 ; hemorrhage, 415 ; soften- ing, 415 ; trauma, 391 ; tubercle, 367 ; tumor, 390, 415, 451 Chalazion, 138 Chemosis, 82, 86, 100, 138 Chloroform narcosis, the pupil in, 280 Chlorosis, 137, 283, 386, 392 Choked disc, 389 Chorea, 382 Choroid, central senile atrophy of the, 252, 324 ; coloboma of the, 259 ; colloid degeneration of the, 251 ; congenital defects of the, 259; diseases of the, 230; de- tachment of the. 254 ; hemor- rhage in the, 252 ; injuries of the, 256 ; tubercle of the, 258, 384 ; tumors of the, 257, 377 Choroidal ring, 77 Choroiditis, 250 central, 252 central senile guttate, 251 disseminated, 230, 250, 319, 371 purulent, 252 Choroido-retinitis, 251, 371 Chromidrosis palpebrarum, 140 Ciliary body, coloboma of the, 244, 259 diseases of the, 230 inflammation of the, 247, 306 injuries of the, 249 new growths of the, 249 muscle, action of the, 10 cramp, of the, 28, 31, 37, 55 Climacteric, the, 367 Cocaine, action of, on the pupil, 122, 190, 197, 203, 220, 279, 329 Coloboma, congenital, of the cho- roid, 259; of the ciliary body, 244, 259 ; of the crystalline lens, 245 ; of the eyelids, 173 ; of the iris, 244 Color-blindness, 16, 396, 402, 419, 499 Color-sense, the, 15, 16, 499 ; method of testing the, 16, 499 ; in periphery of field, 24 ; theo- ries of the, 16 Commotio retinae, 387 Congestion papilla, 369, 389 Conjugate lateral paralysis, 446 Conjunctiva, amyloid degeneration of the, 111 ; cyst of the, 120 ; cysticercus under the, 120 ; der- moid tumor of the, 118 ; diseases of the, 82 ; epithelioma of the, 119; essential shrinking of the, 114 Conjunctiva, hemorrhages in the, 83, 111, 118; hyaline degenera- tion of the. 111 ; hyperaemia of the, 82 ; injuries of the, 121 ; lithiasis of the, 121 ; lupus of the, 113 ; papilloma of the, 119 ; pemphigus of the, 113, 115 ; Pinguecula of the, 117, 118; polypus of the, 118 ; sarcoma of the, 120; syphilitic disease of the, 119, 133; transplantation of the, 150; tubercular disease of the. 111; xerosis of the, 114, 419 Conjunctival complication of small- pox, 110 Conjunctivitis, 83 ; catarrhal, 83, 179, 225; croupous, 108, 114; diphtheritic, 108, 114, 115; fol- licular, 86; gonorrhoeal, 99; granular, 88, 148, 152; phlycten- ular, 123, 124 ; purulent, 89, 90, 92, 99, 152, 185, 195 Corectopia, 243 Cornea, abscess of the, 185, 196, 206, 221 ; absorption ulcer of the, 198; arcus senilis in the, 224 ; bulla of the, 204 ; calcare- ous film of the, 210 ; cauteriza- tion of the, 129, 190 ; cicatrices in the, 130, 187; conical, 217; deep ulcer of the, 101,194; der- moid tumor of the, 118, 219; diseases of the, 184; ectasies of the, 211 ; epithelioma of the, 219; faceted ulcer of the, 198; fibroma of the, 219 ; foreign bodies in the, 195, 199, 219; globosa, 307 ; herpes of the, 200 ; infantile ulceration of the. 510 DISEASES OF THE EYE. with xerophthalmia, 199; in- flammations of the. 184: injuries of the, 195, 206, 219, 306 ; leu- coma of the, 188, 221 ; non- ulcerative inflammations of the, 205; macula of the, 188, 221; nebula of the, 188,221 ; opacities of the, 76, 187, 221 ; paracentesis of the, 128, 191, 195, 198, 218 239 ; ring ulcer of the, 101, 125 198; rodent ulcer of the, 197 sarcoma of the, 219; sclerotizing opacity of the, 210, 224, 227 simple ulcer of the, 194: staphyl oma of the, 93, 106, 110, 113 147, 196, 211, tattooing of the 222 ; transplantation of the 223; tumors of the, 219; ulcera tive inflammations of the, 184 211; ulcus serpens of the, 196 206 Corneal complications in purulent conjunctivitis, 100, 104, 194 in smallpox, 110 Cramp of accommodation, 28, 31, 37, 55 of the orbicularis, 126, 141 Critchett's operation in sympa- thetic ophthalmitis, 269 Croupous conjunctivitis, 108, 114 Crus cerebri, lesion of the, 449, 450 Cupping, pathological, of the optic disc, 78, 288 physiological, of the optic disc, 78 Cyclitis, 133, 209, 225, 247 ; plas- tic, 248 ; purulent, 248 ; serous, 209, 248 Cyst, meibomian, 138 of the conjunctiva, 120 of the iris, 242 Cysticercus in the vitreous humor, 362; under the conjunctiva, 120; under the retina, 380 Cystoid cicatrix, 299, 342 Dacryoadenitis, 182 Dacryocystitis, acute, 98, 181 chronic, 179, 196 Daturine, 279 Decentration of spectacle gl 481 Dermoid tumors of conjunctiva and cornea, 118, 219 De Wecker's operation for staphy- loma corneae, 213 Diabetes. 36, 64, 237, 239, 316, 323, 370, 397, 404, 445 Dianoux's operation for trichiasis, 155 Dilator pupillae, 276 Dioptric unit, the, 6 system of the eye, 8 Dioptry, the, 6 Diphtherial paralysis of accommo- dation, 64 Diphtherial paralysis of orbital muscles, 445 Diphtheritic conjunctivitis, 108, 114, 115 Diplopia in convergent concomitant strabismus, 457, 467 crossed, 431 homonymous, 432 monocular, 241, 352 in insufficiency of the internal recti, 478 in paralysis of orbital muscles, 429 Discission, 316, 317, 346 Distichiasis, 152 operations for, 153 Duboisine, 279 Dyslexia, 416 EccHTMOSis of the conjunctiva, 83, 111, 118 Eclipses, blinding of the retina in, 385 Ectropium, 165 ; cicatricial, 166 ; 169, 486 ; muscular, 165 ; senile, 166 ; spastic, 165 Egyptian ophthalmia, 88 Electrolysis for naevi, 140 for stricture of canaliculus, 176 for trichiasis, 153 Embolism, cerebral, 281 of retinal vessels, 381, 397 Emmetropia. 8 Endocarditis, 254, 285 Entropium, 113, 159; organic, 160 ; operations for, 160; senile, 160, 163, ; spastic, 160, 163 INDEX. 511 Enucleation of the eyeball, 264, 268 Epicanthus, 173 Epilation of eyelashes, 153 Epilepsy, 43, 281, 478 Epiphora, 174, 179 Episcleritis, 225 Epithelioma of the conjunctiva, 119; of the cornea, 219; of the eyelid, 141 Erysipelas of the eyelids, 132, 181, 392, 484 Erythropsia, 354, 422 Eserine, 86 189, 192, 193, 196, 218, 219, 279, 331, 333 Evisceration of the eyeball, 214, 266 Exophthalmic goitre, 147, 492 Exophthalmos, pulsating, 489 Expression of granulations, 95 i Eyeballs, the motions of the, and their derangements, 424 Eyelids, adenoma of the, 141 ; chromidrosis of the, 140 ; colo- boma of the, 173 ; cramp of the, 126, 141; diseases of the, 132; ecchymosis of the, 172; eczema of the, 132, 135 ; emphysema of the, 172 ; epithelioma of the, 141; erysipelas of the, 132, 181, 392, 487 ; eversion of the, 165 ; herpeszoster of the, 132; injuries of the, 172 ; inversion of the, 159 ; lupus of the, 141 ; milium of the, 139 ; molluscum of the, 139; n?evu8 of the, 140 ; restora- tion of an, 170 ; rodent ulcer of the, 134; sarcoma of the, 141; syphilitic sores on the, 133, 134 ; vaccine vesicles on the, 134 Facet on the cornea, 131 Facial centre, lesion of the, 147 Far point and near point, 10 Fluorescin, 186, 197 Focal illumination, 76 Focal interval, 40 length of a lens, 3 Focus, conjugate, 3 principal, of a lens, 3 virtual, 4 Follicular conjunctivitis, 83 Fomentations, warm. 190 Form-sense, the, 15, 18, 414 Fourth ventricle, diseases of floor of, 443, 445 Fovea centralis, 79, 81 Fracture of base of the skull, 118, 172 Fundus oculi, the normal, 77, 79 Gaillard's sutures for entro- pium, 163 Galvano-cautery, 195, 197,198, 206, 219, 342 Glaucoma, 111, 204, 207, 210, 239, 246, 283, 285 ; acute, 291 ; chronic, 287 ; etiology of, 295 ; •fulminans, 294 ; hemorrhagic, 307, 368 ; pathology of, 295 Glaucoma, primary, 285 secondary, 227, 236, 240, 242, 248, 248, 257, 267, 305, 306, 321, 346, 348 sub-acute, 294 treatment of, 298 Glaucomatous degeneration, 294 ring, 290 Glioma of the brain, 384 ; of the optic nerve, 402 ; of the retina, 230, 258, 355, 384 Goitre, exophthalmic, 147, 492 Gonorrhoeal arthritis, 107, 233 ; conjunctivitis, 99 ; iritis, 233 Gout, 367 Granular conjunctivitis, 88, 111, 114, 197 Granuloma of the iris, 242 Green's operation for entropium, 161 H.EMATEMESIS, 367, 405 Haemophthalmos, 228 Hay fever, 87 Headache, 43 Hemiachromatopsia, 413 Hemianaesthesia, 414, 416 Hemianopsia, 407 ; complete and partial, 408, 412 ; homonymous, 273, 408, 412 ; localization of lesion in, 412 ; nasal, 409, 412 ; relative and absolute, 408 ; su- perior and inferior, 408, 412 ; temporal, 408, 412 512 DISEASES OF THE EYE. Hemiopic pupil, the, 415 Hemiplegia, 414 crossed, 147, 450, 452 Hemorrhage in the anterior cham- ber, 228, 240 Hemorrhoids, 366 Bering's drop experiment, 468 footnote theory of the color-sense, 16 Hernia cerebri, 491 Herpes cornese, 200 zoster ophthalmicus, 132, 201 Heterophthalmos, 243 Hippus, 278 Holmgren's tests for color-blind- ness, 17, and Appendix I Hooping cough, 118, 202 Hordeolum, 138 Hotz's operation for entropium, 164 Hydrocephalus, 391. 400 Hydrophthalmos, 307 Hyoscyamine, 279 Hypermetropia, 25 ; amplitude of accommodation in, 28; angle 7 in, 28 ; asthenopia in, 30 ; axial, 25 ; curvature, 25 ; cramp of ciliary muscle in, 28 ; determina- tion of degree of, 26, 65, 68 ; direct ophthalmoscopic method in, 65 ; internal strabismus in, 30, 464 ; latent, 29, 31 ; mani- fest, 29, 31 ; prescribing of spec- tacles in, 30 ; retinoscopy in, 68 Hypermetropic astigmatism. 41 Hyphema, 228, 240 Hypopyon, 125, 186, 194, 195, 201, 206, 248, 359 Hysteria, 281, 386, 887, 418 Illaqueatio, 153 Image formed by a lens, 5 real, 5 virtual, 5 Influenza, epidemic, 54, 445 Intermittent fever, 202 Internal recti, insuflficiency of the, 37, 477 capsule, lesion of the, 414 Intestinal worms, 283 Intraocular growths, 47 Intraocular tension, 104, 234. 235, 239, 245, 248, 252, 257, 285, 348 Inverted ophthalmoscopic image, 60 Iridectomy, 245, 298 in cataract operations, 332, 343 for glaucoma, 245, 246, 298, 367 Irideremia, 242, 245 Irido-choroiditis, 236, 242, 260 Iridocyclitis, 209, 210, 230, 236, 260 Iridodialysis, 241 Iridodonesis, 352 Iridotomy, 247, 351 Iridoplegia, 283 Iris, absence of the, 242, 545 ; an- teversion of the, 242 ; coloboma of the, 244 ; cysts of the, 242 ; diseases of the. 230 ; foreign bodies in the, 240 : granuloma of the, 242 ; injuries of the, 240 ; malformations of the, 243 ; new growths in the, 242; operations on the, 245; persistent pupillary membrane of the, 243; posterior limiting membrane of the, 276 ; prolapse of the, 106, 192, 193, 212 ; retroflexion of the, 241 ; rupture of the sphincter of the; 241 ; sarcoma of the, 243 , trembling of the, 352 ; tubercle of the, 243 Iritis, 84, 93, 95, 111. 125, 231, 342 : diabetic, 237 ; gonorrhoeal, 233 ; parenchymatous, 231, 234; plastic, 231, 233 ; purulent, 231, 240 ; rheumatic, 233.239 ; serous, 231, 233, 307 ; syphilitic, 233, 234, 240 ; treatment of, 237 Jacob's ulcer, 134 Jequirity, 97 Keratitis, 110, 116, 124, 125, 184; bullosa, 204 ; dendriform, 205 ; difi'use interstitial, 206 ; fascicu- lar, 124, 129; neuro-paralytic, 199; phlyctenular, 123, 125, 199 ; punctata, 209, 233, 248, 262 ; riband-like, 210; striped, 340; thread-like, 203 Keratoconus, 217 INDEX. 513 Lachrymal apparatus, diseases of the, 174 canaliculus, obstruction of the, 175 duct, stricture of the, 176 fistula, 182 gland, extirpation of the, 183 hypertrophy of the, 183 inflammation of the, 182 obstruction, 82, 175, 177 punctum, aversion of the, 84, 132, 166, 174 inversion of the, 174 malposition of the, 174 occlusion of the, 174 stenosis of the, 174 sac, acute inflammation of the, 181. blenorrhoea of the, 179 mucocele of the, 180 obliteration of the, 182 Lagophthalmos, 147 Lamellar cataract, 317 Lamina cribrosa, 77 Lead poisoning, 393, 445 Lens, action of a concave, on rays, 2 ; of a convex, on rays, 2, 3 : focal length of a, 3 ; optical cen- tre of a, 2 ; principal axis of a, 2 ; principal focus of a, 3 ; the image formed by a, 4 (crystalline), absence of the, 352 ; calcification of the, 236 ; change of, in accom- modation, 10; coloboma of the, 244 ; diseases of the, 309 ; dislocation of the, 228, 306, 351 ; injuries to the, 306, 320 Lenses, cylindrical, 45 numbering of the trial, 6 spherical, 2 Lental astigmatism, 48 Lenticonus, 3, 5 Leucocythemia, 370 Leucoma, 188, 221 adherent, 106, 195, 196, 222 Lice in the eyelashes. 137 Light difi'erence (L D.), 15 minimum (L. M.), 15 Light-sense, the, 15, 291, 372, 373, 374, 400, 414 Linear cataract extraction, 325 Lithiasis of the conjunctiva, 121 Localization, cerebral, 147, 412, 449 Locomotor ataxy, 281, 283, 445 Lupus of the conjunctiva, 113 of the eyelid, 141 Macula lutea, diseases of the, 36 ; nervous supply of, 410 ; normal appearances of the, 79 ; ophthal- moscopic examination of the, 63 Macula cornea, 189, 221 Madarosis, 134 Maddox's rod test, 479 Mania, acute, 282, 283 Massage, 88, 222, 224, 226, 383 Measles, 84, 206, 254 Media, the intraocular, 7 the refracting, 8 Meibomian cyst, 138 Melancholia, 283 Meningitis, 269, 280, 390, 484 cerebro-spinal, 253, 254, 280, 390 tubercular, 280, 390 Menstruation, 227, 366, 392, 394 Mental derangement, sign of, 53, 346 Metamorphopsia, 372 Metre angle, 13, 479 Metria, 236, 254, 365, 484 Metrical system, 6 Micropsia, 53, 372 Military ophthalmia, 88 Milium, 139 Mind-blindness, 417 Mirror, concave, 7 plane, 6 Molluscum, 139 Morphium, action of, on the pupil, 280 Motions of the eyeballs, 424 Mucocele, 180 Mules's operation, 215, 264, 266 Muscarine, 279 Muscae volitantes, 357 Mydriasis, 53, 282, 437, 484 traumatic, 242 Mydriatics, action of the, 279 Myelitis, 390 Myopia, 25, 31, 377 ; amplitude of 514 DISEASES OF THE EYE. accommodation in, 34 ; angle > in, 35 ; axial, 31 ; complications of, 36, 377; cramp of accommo- dation in, 37 ; curvature, 32 ; detachment of retina in, 36, 377 ; determination of the degree of, 32, 65, 71 ; direct ophthalmo- scopic method in, 65 ; insuffi- ciency of the internal recti in, 37, 456, 477 ; macular disease in, 36 ; management of, 37 ; opa- cities in vitreous humor in, 37 ; posterior staphyloma in, 36 ; pre- scribing of spectacles in, 38 ; progressive, 36, 37 ; retinal hem- orrhage in, 36 Myopic astigmatism, 41 Myosarcoma of ciliary body, 250 Myosis, 280 spinal, 281 Myotics, action of the, 79 use of, in glaucoma, 304 N^YUS of the eyelids, 140 Nasal catarrh, 180, 181, 202 duct, stricture of the, 176, 179 Near point, 10 Nephritis, 368. 420 Neurasthenia, 284 Neurectomy, optic, 266, 270 Neurotomy, optic, 266 Nicotine, 280 Night-blindness, 115, 372, 373, 419 Nuclear paralysis, 443 Nyctalopia (see Night-blindness) Nystagmus, 260, 317, 483 Occipital Lobe, lesion of the, 412 Omphalo-phlebitis, 254 Opaque nerve-fibres, 78 Ophthalmia, Egyptian, 88 ; gonor- rhoea!, 99; granular, 88, 148, 152; military, 88 ; phlyctenular, 123 ; purulent, 99, 152 ; tarsi, 135 Ophthalmoplegia, externa, 443 interna, 53, 443 Ophthalmoscope, the, 56 ; direct method of examination by, 68 ; estimation of refraction with the, 63 ; indirect method of exami- nation by the, 60 Optic nerve, the, 62, 77 atrophv of the, 132, 230, 301,392,399,403,403, 484, 486, 487 colloid outgrowths from the, 403 diseases of the, 389 injuries of the, 403 resection of the, 255 tumors of the, 402 papilla, 62, 77 cupping of the, 78 287 radiations, lesions of the, 414 tract, lesion of an, 415 neuritis, 230, 261, 389, 400, 487 retrobulbar, 393, 395 with dropping of watf-ry fluid from nostril, 398 Optical axis, the, 8 centre, the, 8 Orbit, carcinoma and sarcoma of the, 489 ; caries of the, 486 ; cysts of the, 488 ; diseases of the, 484; diseases of neighboring cav- ities, 490 ; exostosis of the, 488 ; foreign bodies in the, 487 ; frac- ture of the, 172, 487 ; inflam- mation in the, 392 ; injuries of the, 486 ; penetrating wounds of the, 487 ; syphilitic gumma of the, 485 ; tumors of the, 147, 392, 487 Orbital cellulitis, 484 ; muscles, paralysis of the, 429 ; periostitis, 485 Osteo sarcoma of the choroid, 243 Ozaena, 179 Pagenstecher's ointment, 128 Pannus, 92, 199 Panophthalmitis, 110, 200, 228, 253, 261, 355, 365 Papillitis, 389 Papilloma of conjunctiva, 119 Paracentesis of the cornea, 129, 191, 192, 195, 198, 218, 239 Parallax, 78, 289 Parallel rays, 8 Paralysis of accommodation, 53, 443 ; bulbar, 54, 282, 445 ; of the INDEX. 515 cervical sympathetic, 282 ; con- jugate lateral, 446 ; diphtherial, 53, 445 ; of the facial nerve, 147, 452 ; of the fifth nerve, 109 ; of the fourth nerve, 433, 451 ; general, of the insane, 282, 283, 401 ; intermittent of the third nerve, 442 ; of the levator palpe- brae (see Ptosis); nuclear, 443; of the orbital muscles, 429 ; of the sixth nerve, 53, 431, 452 ; of the sphincter iridis (see Mydriasis) ; of the third nerve, 53, 449, 451 Pemphigus of the conjunctiva, 113, 115, 148 Perimeter, the 21 Peritomy, 98 Phlyctenular conjunctivitis, 123, 124 keratitis, 123, 125, 199, 201 Phosphene, 377 Photophobia, 87, 93, 100, 125 Phtheiriasis ciliorum, 137 Phthisis anterior, 262 bulbi, 228, 236, 249 Physostigmine, 279 Pilocarpine, 189, 279 Pineal gland, tumor of the, 451 Pinguecula, 117 Pneumonia, 200, 202, 237 Polycoria, 243 Polyopia, monocular, 313 Polypus of the conjunctiva, 118 Pons, lesions of the, 147, 282, 445, 447, 452 Posterior staphyloma, 36, 254 Pregnancy, 368, 382, 420 Presbyopia, 49 Prism, action of a, 1 Proptosis, 485, 487 Pseudo-glioma, 253, 355, 384 Psychical blindness, 417 Pterygium, IIG Ptosis, 141, 173, 414, 436, 443, 444, 449 with associated movements, 146 Pulsation in retinal vessels, 81, 290, 294, 493 Pulvinar, lesion in the, 413, 414 Punctum lachrymale, eversion of the, 84, 132, 166, 174; inversion of the, 174; occlusion of the, 174 Punctum proximum, 10 remotum, 10, 32 footnote Pupil, action of the mydriatics on the, 279 action of the myotics on the, 279 the Argyll- Robertson, 281 artificial, 246 change of, in accommodation, 10, 275 contraction of the, 272 in chloroform narcosis, 280 dilatation of the, 276 exclusion of the, 231 hemiopic, 415 hippus of the, 278 influence of the fifth nerve on the, 279 of the optic nerve on the, 272 of the sympathetic on the, 276 of the third nerve on the, 272 malposition of the, 243 occlusion of the, 232 reflex contraction of the, 272 size of the, in disease, 280 in health, 272 supernumerary, 243 unrest of the, 278 Pupillary membrane, persistent, 243 Purulent conjunctivitis, 89, 90, 99, 152, 185, 194 inflammation of vitreous hu- mor, 355 iritis, 231, 240 retinitis, 365 Pyaemia, 254, 484 Quinine amaurosis, 373 Recurrent fever, 237 Red vision, 353, 422 Reflection, phenomenon of, 6 Refraction and accommodation, normal, 7 and accommodation, abnor- mal, 25 516 DISEASES OF THE EYE. Refraction, estimation of the, by the upright image, 63 estimation of the, by retino- scopy, 68 the phenomenon of, 1 Resection of the optic nerve, 266, 270 Retina, adaptation of the, 16 foot- note, 419 ; aneurism of the cen- tral artery of the, 381 ; apoplexy of the, 367 ; blinding of the, by direct sunlight, 385 ; cysticercus under the, 380 ; detachment of the, 36, 236, 248, 257, 320, 357, 368, 369, 376; development of connective tissue in the, 375 ; diseases of the, 365 ; embolism of the central artery of the, 381, 398 ; glioma of the, 384 ; hemor- rhage in the, 36, 111, 307, 365, 367,371,375; hyperaesthesia of the, 386, 387, 418; normal, 78; septic aflFections of the, 111, 365 ; thrombosis of the central artery of the, 384 ; traumatic oedema of the, 387; anaesthesia of the, 387 Retinal affections in diabetes, 370 anaesthesia, 385 asthenopia, 385, 460 ischsemia, 373 vessels, the, 79 Retinitis, 230; albuminuric, 366, 368, 389, 394; hemorrhagic, 365, 370; leucfemic, 370; pig- mentosa, 373, 419 ; proliferans, 375 ; punctata albescens, 375 ; purulent, 111, 365; syphilitic, 371 Retinoscopy, 68 Rheumatism, 142. 148, 210, 224, 226, 227, 232, 233, 236, 239, 393, 404, 485, 486 Rodent ulcer of the cornea, 197 of the eyelid, 134 S.'Emisch's ulcer, 195 Sarcoma of the choroid, 256 ; of the ciliary body, 249 ; of the conjunctiva, 120; of the cornea, 219 ; of the eyelid, 141 ; of the iris, 243 ; of the sclerotic, 229 Scarlatina, 84, 420, 484 Scleritis, 210, 224, 225, 226 Sclerosis, multiple, 394, 398, 401, 483 Sclerotic, diseases of the, 225 ; in- juries of the, 227, 377; ring, 77; tumors of the, 229 Sclerotizing opacity of the cornea, 210, 224, 227 Sclerotomy, 303 Scorbutus, 420 Scotoma, central, 252, 396, 402, 404, 419 ; positive, 357, 372, 385 ; relative, 375, 396 Septicaemia, 236, 365 Shadow-test, the, 68 Short-sight, 31 Sight, the sense of, 15 Skull, fracture of the, 118, 172, 400, 403 Smallpox, conjunctival and cor- neal complications of, 111, 206 ocular sequelae of, 84, 111, 206, 236 Snellen's operation for entropium, 160; sutures, 166 Snow-blindness, 420 Soul-blindness, 417 Spectacles in accommodative as- thenopia, 30, 31 ; in albinismus, 260 ; in anisometropia, 49 ; in aphakia, 353 ; in astigmatism, 45 ; in conical cornea, 217 ; in convergent strabismus, 466, 476; in cramp of accommodation, 29; in hypermetropia, 30, 82 ; in in- cipient cataract, 315; in insuffi- ciency of the internal recti, 480 ; in irideremia, 245 ; in myopia, 38 ; in nebulous cornea, 222 ; in paralysis of accommodation, 55 ; in paralysis of orbital muscles, 441 ; in presbyopia, 51, 82 Sphenoidal fissure, periostitis at the, 53 Spinal amaurosis, 401 cord, diseases of the, 281, 282, 283, 284, 394, 398, 400 myosis, 281 Spring catarrh, 87 Squint (see Strabismus) INDEX. 517 Staphyloma, anterior, 227, 294 of the cornea, 93, 106, 110, 196, 211 posterior, 36, 254 Stenopaeic spectacles, 218, 222, 260, 818 Stomach, hemorrhao;e from the, 404 Strabismus, apparent convergent. 35 ; apparent divergent, 28 Strabismus, convergent concomi- tant, 30, 453 ; advancement of capsule of tenon in, 452; advance- ment of external rectus in, 474 ; amblyopia in, 458 ; angle of, 465 ; clinical varieties of, 460 : dangers of operation for, 476 : hypermetropia in, 30, 454, 466 ; 476 ; measurement of, 460; mo- bility of eye in, 466 ; operation for, 469, 471 ; orthoptic treatment of, 466 ; single vision in, 457 ; tenotomy in, 471 Strabismus, divergent concomitant, 477; tenotomy in, 481; treat- ment of. 481 Streatfield's operation for entro- pium, 160 Strumous ophthalmia, 123 Stye, 138 Symblepharon, 122, 148^ ^ Sympathetic ophthalmitis, 209, 210, 215, 242, 249. 253, 260, 359 Sympathetic irritation, 261, 418 Synchysis, 356, 357 scintillans, 357 Synechia, anterior, 106, 242, 306 posterior, 231, 235, 236, 306 Syphilis, 53, 89, 119, 133, 142, 148. 176. 208, 210, 224. 226, 227, 230, 233, 234, 236, 240, 243, 251, 252, 254, 355, 357, 366, 371, 375, 392, 398, 440, 485, 486 Syphilis of the conjunctiva, 119, 133 inherited, 208, 236, 251, 254, 371 Syphilitic choroido-retinitis, 371 ; iritis, 233, 234, 240; retinitis, 371 Tabes dorsalis, 2S1, 283, 445 Tarsal tumor, 138 Tarsorraphy, 148, 165 Tattooing the cornea, 222 Teeth, diseases of the, 484 Tension of the eyeball, 285, 286 Test-types, 19 Third pair, paralysis of the, 53, 450, 451 Trachoma, 88 Transplantation of conjunctiva, 150; of cornea, 223: of skin, 170 Trial lenses, numbering of the, Trichiasis, 152 operations for, 153 Tubercle of the brain, 367 of the choroid, 258, 384 of the conjunctiva. 111, 134 of the iris, 243 Tubercular meningitis, 280, 390 Typhoid fever, 237, 484 Upright ophthalmoscopic image, 58 Uremia, 369, 370, 420 Urfemic amblyopia, 420 Uterine derangements, 386 hemorrhage, 404 Uveal tract, diseases of the, 230 Vaccine vesicles on the eyelids, 134 Van Milligen's operation for tri- chiasis, 158 Virtual focus, 4 image, 5 Vision, acuteness of, 18: binocular, 468, 468 footnote, 477, 477 foot- note : central, 20 : eccentric, 20 ; field of, 20 ; defects of. which disqualify for the army, 5C2 ; for the Army Medical Department, 502 ; for the British Mercantile Service, 505 ; for the Home Civil Service, 503 ; for the Indian Civil Service, 503 ; for the Indian Marine Service, 505 ; for the Indian Medical Service, 504 ; for the Navy, 503 ; for the Royal Irish Constabulary, 505 Visual angle, the, 19 centre, 409 lesion at the, 412 ' memory, 417 518 DISEASES OF THE EYE. Vitreous humor, cysticercus in the, 362; detachment of the, 362; diseases of the, 855. 377 ; fluidity of the, 356, 357; foreign bodies in the, 358 ; hemorrhage in the, 356, 369 ; inflammatory pro- cesses in the, 355, 359 ; muscae volitantes of the, 357 ; opacities in the, 37, 111, 230, 236, 248, 355, 356, 371 ; persistent hya- loid artery in the, 362; puru- lent inflammation of the, 257 ; 355, 359 Von Graefe's operation for cata- ract, 329; for conical cornea, 218 ; for entropium, 164 ; in sym- pathetic ophthalmitis, 267 Vossius's operation for trichiasis, 157 Wharton Jones's operation for ectropium, 169 Whooping cough, 118, 254 Word-blindness, 415 Xanthelasma of the eyelids, 140 Xerophthalmia, 114, 419 ; with ulceration of cornea, 199 Young-Helmholtz theory of the color-sense, 16 Zonula of Zinn, change of, in ac- commodation, 10 Zonular cataract, 317 CATALOGUE No. 7. JANUARY, 1894. BOOKS FOR STUDENTS, INCLUDING THE PQUIZ-COMPENDS? CONTENTS. PAGE PAGE! New Series of Manuals, 2,^,4,'^ Obstetrics 10 Anatomy, . .6 Pathology, Histology, . .11 Biology, . II Pharmacy is Chemistry, . . 6 Physical Diagnosis, . . 11 Children's Diseases, . 7 Physiology, . . . .11 Dentistry, , 8 Practice of Medicine, . ii, 12 Dictionaries, 8,16 Prescription Books, . . 12 Eye Diseases, . 8 ?Quiz-Compends? . 14,15 Electricity, . • 9 Skin Diseases, . . .12 Gynaecology, . 10 Surgery and Bandaging, . 13 Hygiene, • 9 Therapeutics, . . .9 Materia Medica, . • 9 Urine and Urinary Organs, 13 Medical Jurisprudence . 10 Venereal Diseases, . . 13 Nervous Diseases, . 10 PUBLISHED BY P. BLAKISTON, SON & CO., Medical Booksellers, Importers and Publishers, LARGE STOCK OF ALL STUDENTS' BOOKS, AT THE LOWEST PRICES. 1012 Walnut Street, Philadelphia. %* For sale by all Booksellers, or any book will be sent by mail^ postpaid, upon receipt of price. Catalogues of books on all branches of Medicine, Dentistry, Pharmacy, etc., supplied upon application. GOULD'S DICTIONARY See Page 16. 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Compend of Diseases of the Eye and Refraction. 2d Ed. Enlarged. 71 Illus. 39 Formulae. Cloth. I.oo; Interleaved for Notes, 1.25 ij®" See pages 2to S for list of Students' Manuals. STUDENTS' TEXT-BOOKS AND MANUALS. 9 ELECTRICITY. Bigelow. Plain Talks on Medical Electricity. Cloth, i.oo Mason's Compend of Medical Electricity. Cloth, i.oo Steavenson and Jones. Medical Electricity. A Practical Handbook. Just Ready. Illustrated. i2mo. Cloth, 2.50 HYGIENE. Coplin and Bevan, Practical Hygiene. By W. M. L. Cop- lin, Adjunct Professor of Hygiene, Jefferson Medical College, Philadelphia, and Dr. D. Bevan. Illustrated. Cloth, 4.00 Parkes' (Ed. A.) Practical Hygiene. Seventh Edition, en- larged. Illustrated. 8vo. Cloth, 4.50 Parkes' (L. C.) Manual of Hygiene and Public Health. Second Edition. 12010. Cloth, 2.50 ■Wilson's Handbook of Hygiene and Sanitary Science. Seventh Edition. Revised and Illustrated. Cloth, 3.25 MATERIA MEDICA AND THERAPEUTICS. Potter's Compend of Materia Medica, Therapeutics, and Prescription 'Writing. Fifth Edition, revised and improved. See page i^. Cloth, i.oo; Interleaved for Notes, 1.25 Uavis. Essentials of Materia Medica and Prescription "Writing. By J. Aubrey Davis, m.d., Demonstrator of Obstet- rics and Quiz-Master on Materia Medica, University of Penn- sylvania. i2mo. Interleaved. Net, 1.50 Biddle's Materia Medica. Twelfth Edition. By the late John B. Biddle, m.d. Revised by Clement Biddle, m.d. 8vo. Illustrated. Cloth, 4.25; Leather, 5.00 Potter. Handbook of Materia Medica, Pharmacy, and Therapeutics. Including Action of Medicines, Special Thera- peutics, Pharmacology, etc. By Saml. O. L. Potter, m.d., M.R.c.p. (Lond.), Professor of the Practice of Medicine in Cooper Medical College, San Francisco. Fourth Revised and Enlarged Edition. 776 pages. 8vo. Cloth, 4.00; Leather, 5.00 White and W^ilcox. Materia Medica, Pharmacy, Phar- macology, and Therapeutics. A Handbook for Students. By Wm. Hale White, m.d., f.r.c.p., etc., Physician to and Lecturer on Materia Medica, Guy's Hospital. Revised by Reynold W. Wilcox, m.d.. Professor of Clinical Medicine at the New York Post Graduate Medical School, Assistant Physician Bellevue Hospital, etc. American Edition. Clo., 3.00; Lea., 3.50 J¥S^ See pages 14 and /j for list of f Quiz- Comp ends f 10 STUDENTS' TEXT-BOOKS AND MANUALS. MEDICAL JURISPRUDENCE. Reese. A Text-book of Medical Jurisprudence and Toxi- cology. By John J. Reese, m.d., Professor of Medical Juris- prudence and Toxicology in the Medical Department of the University of Pennsylvania ; Physician to St. Joseph's Hospital.. Third Edition. Cloth, 3.00; Leather, 3.50- NERVOUS DISEASES. Gowers. Manual of Diseases of the Nervous System, A Complete Textbook. By William R. Gowers, m.d.. Prof. Clinical Medicine, University College, London. Physician ta National Hospital for the Paralyzed and Epileptic. Second Edition. Revised, Enlarged, and in many parts Rewritten. With many new Illustrations. Octavo. Vol. I. Diseases of the Nerves and Spinal Cord. 616 pages. Cloth, 3.5a Vol. II. Diseases of the Brain and Cranial Nerves. General and Functional Diseases. Cloth, 4.50 Ormerod. Diseases of Nervous System, Student's Guide to. By J. A. Ormerod, m d., Uxon., f.k.c.p. (London), Member Path- ological. Clinical, Ophthalmological, and Neurological Societies, Physician to National Hospital for Paralyzed and Epileptic and to City of London Hospital for Diseases of the Chest, Demon- strator of Morbid Anatomy, St. Bartholomew's Hospital, etc^ With 75 Wood Engravings. Cloth, 2.oo> OBSTETRICS AND GYNECOLOGY. Davis. A Manual of Obstetrics. By Edw. P. Davis, Clinical Lecturer on Obstetrics, Jefferson Medical College, Philadelphia. Colored Plates, and 136 other Illustrations. i2mo. Cloth, 2.00 Byford. Diseases of Women. The Practice of Medicine and Surgery, as applied to the Diseases and Accidents Incident Women. By W. H. Byford, a.m., m.d.. Professor of Gyna;colo, Surgery, as applied to the Diseases and Accidents Incident to Women. By W. H. Byford, a.m., m.d.. Professor of Gynaecology in Rush Medical College and of Obstetrics in the Woman's Med- ical College, etc., and Henrj' T. Byford, m.d.. Surgeon to the Woman's Hospital of Chicago. Fourth Edition. Revised and Enlarged. 306 Illustrations, over 100 of which are original. Octavo. 832 pages. Cloth, 5.00 ; Leather, 6.00. Lewers' Diseases of 'Women. A Practical Text-book. 13^ Illustrations. Second Edition. Cloth, 2.50- Parvin's Winckel's Diseases of Women. Second Edition. Including a Section on Diseases of the Bladder and Urethra. 150 III us. Revised. Seepages. Cloth, 3.00; Leather, 3.50- Wells. Compend of Gynaecology. Illustrated. Cloth, i.oo Winckel's Obstetrics. A Text-book on Midwifery, includ- ing the Diseases of Childbed. By Dr. F. Winckel, Professor of Gynaecology, and Director of the Royal University Clinic for Women, in i\lunich. Authorized Translation, by J Clifton Edgar, m.d., Lecturer on Obstetrics, University Medical Col- lege, New York, with nearly 200 handsome Illustrations, the majority of which are original. 8vo. Cloth, 6.00 ; Leather, 7.00 4S=- See page* 2 to 5 for list 0/ Netv Manuals. STUDENTS' TEXT-BOOKS AND MANUALS. 11 Obstetrics and Gyncecology : — Continued. Landis' Compend of Obstetrics. Illustrated. 5th Edition, Enlarged. By Wells. Cloth, i. 00 ; Interleaved for Notes, 1.25 Galabin's Midwifery. By A. Lewis Galabin, m.d., f.r.c.p. 227 Illustrations. Leather, 3.50 PATHOLOGY, HISTOLOGY, ETC. Stirling. Outlines of Practical Histology. A ^Manual for Students. 2d Edition. 368 Illustrations. i2mo. Cloth, 3.00 Wethered. Medical Microscopy. By Frank J. Wethered. M.D., M R.C.P. 98 Illustrations. Cloth, 2.50 Hall. Compend of General Pathology and Morbid Anat- omy. Illustrated. Cloth, i.oo; Interleaved, 1.25 Gilliam's Essentials of Pathology. A Handbook for Students. 47 Illustrations. i2mo. Cloth, 2.00 Virchow's Post-Mortem Examinations. 3d Ed. Cloth, i.co PHYSICAL DIAGNOSIS. Fenwick. Student's Guide to Physical Diagnosis. 7th Edition. 117 Illustrations. i2mo. Cloth, 2.25 Tyson's Student's Handbook of Physical Diagnosis. Illus- trated. 2d Edition. i2mo. Cloth, 1.50 PHYSIOLOGY. Yeo's Physiology. Sixth Edition. The most Popular Stu- dents' Book. By Gerald F. Yeo, m.d., f.r.c.s., Professor of Physiology in iting's College, London. Small Octavo. 254 carefully printed Illustrations. With a Full Glossary' and Index. See page 3. Cloth, 3.00; Leather, 3.50 Brubaker's Compend of Physiology. Illustrated. Seventh Edition. Cloth, i.oo; Interleaved for Notes, 1.25 Kirke's Physiology. New 13th Ed. Thoroughly Revised and Enlarged. 502 Illustrations, some of which are printed in colors. {Blakiston's Authorized Edition.) Red CI. , 4.00 ; Leather, 5.00 Landois' Human Physiology. Including Histology and Micro- scopical Anatomy, and with special reference to Practical Medi- cine. Fourth Edition. Translated and Edited by Prof Stirling. 845 Illustrations. Cloth, 7.00 ; Leather, 8.00 " With this Text-book at his command, no student could fail in his examination." — Lnncet. Sanderson's Physiological Laboratory. Being Practical Ex- ercises for the Student. 350 Illustrations. 8vo. Cloth, 5.00 PRACTICE. Taylor. Practice of Medicine. A Manual. By Frederick Tavlor, m.d.. Physician to, and Lecturer on Medicine at, Guy's Hospital, London ; Physician to Evelina Hospital for Sick Chil- dren, and Examiner in Materia Medica and Pharmaceutical Chemistry, University of London. Cloth, 2.00; Leather, 2.50 M^S' See pages 14 and 15 for list of ? Quiz-Compends f 12 STUDENTS' TEXT-BOOKS AND MANUALS. Practice : — Continued. Roberts' Practice. New Revised Edition. A Handbook of the Theory and Practice of Medicine. By Frederick T. Roberts, m.d., m.r.c.p., Professor of Clinical Medicine and Therapeutics in University College Hospital, London. Seventh Edition. Octavo. Cloth, 5.50 ; Sheep, 6.50 Hughes. Compend of the Practice of Medicine. 4th Edi- tion. Two parts, each, Cloth, i.oo; Interleaved for Notes, 1.25 Part i. — Continued, Eruptive and Periodical Fevers, Diseases of the Stomach, Intestines, Peritoneum, Biliary Passages, Liver, Kidneys, etc., and General Diseases, etc. Part ii. — Diseases of the Respiratory System, Circulatory System, and Nervous System ; Diseases of the Blood, etc. Physicians' Edition. Fourth Edition. Including a Section on Skin Diseases. With Index, i vol. Full Morocco, Gilt, 2.50 From John A. Robinson, M.D., Assistant to Chair of Clinical Medicine , now Lecturer on Materia Medica, Rush Medical Col- lege, Chicago. " Meets with my hearty approbation as a substitute for the ordinary note books almost universally used by medical students. It is concise, accurate, well arranged, and lucid, . . . just the thing for students to use while studying physical diagnosis and the more practical departments of medicine." PRESCRIPTION BOOKS. Wythe's Dose and Symptom Book. Containing the Doses and Uses of all the principal Articles of the Materia Medica, etc. Seventeenth Edition. Completely Revised and Rewritten, yusi Ready. 32mo. Cloth, i. 00; Pocket-book style, 1.25 Pereira's Physician's Prescription Book. Containing Lists of Terms, Phrases, Contractions, and Abbreviations used in Prescriptions, Explanatory Notes, Grammatical Construction of Prescriptions, etc., etc. By Professor Jonathan Pereira, m.d. Sixteenth Edition. 32mo. Cloth, i. 00; Pocket-book style, 1.25 PHARMACY. Stewart's Compend of Pharmacy. Based upon Remington's Text-book of Pharmacy. Fourth Edition, Revised in accordance with US P., i8go. Cloth, i.oo ; Interleaved for Notes, 1.25 Robinson. Latin Grammar of Pharmacy and Medicine. By H. D. Robinson, ph.d., Professor of Latin Language and Literature, University of Kansas, Lawrence. With an Intro- duction by L. E. Sayre, ph.g.. 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This, with the Section on Ligation ol Arteries, forms an ample Text-book for the Surgical Laboratory. "Walsham. Manual of Practical Surgery. Third Edition. By Wm. J. Walsham. m.d., f.r c.s., Asst. Surg, to, and Dem- of Practical Surg, in, St. Bartholomew's Hospital; Surgeon to Metropolitan Free Hospital, London. With 318 Engravings. See page 2. Cloth, 3.00 ; Leather, 3.50 URINE, URINARY ORGANS, ETC. Holland. The Urine, and Common Poisons and The Milk. Chemical and Microscopical, for Laboratory Use. Illus- trated. Fourth Edition. i2mo. Interleaved. Cloth, i.oo Ralfe. Kidney Diseases and Urinary Derangements. 42 Illus- trations. i2mo. 572 pages. Cloth, 2. 75 Marshall and Smith. On the Urine. The Chemical Analysis ot the Urine. Colored Plates. i2mo. Cloth, i.oo Memminger. Diagnosis by the Urine. Illus. Cloth, i.oo Tyson. On the Urine. A Practical Guide to the Examination of Urine. With Colored Plates and Wood Engravings. Eighth * 'Edition, Enlarged. i2mo. 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Cloth, each $i.oo. Interleaved for Notes, $1.25. No. I. HUMAN ANATOMY, "Based upon Gray." Fifth Enlarged Edition, including Visceral Anatomy, formerly published separately. 16 Lithograph Plates, New Tables, and 117 other Illustrations. By Samuel O. L. Potter, m.a., m.d., m.r.c.p. (Lond.), late A. A. Surgeon U. S. Army, Professor of Practice, Cooper Medical College, San Fran- cisco. Nos. 2 and 3. PRACTICE OF MEDICINE. Fourth Edi- tion. By Daniel E. Hughes, m.d., Demonstrator of Clinical Medicine in Jefferson Medical College, Philadelphia. In two parts. Part I. — Continued, Eruptive, and Periodical Fevers, Diseases of the Stomach, Intestines, Peritoneum, Biliary Passages, Liver, Kidneys, etc. (including Tests for Urine), General Diseases, etc. Part II. — Diseases of the Respiratory System (includmg Phy- sical Diagnosis), Circulatory System, and Nervous System; Dis- eases of the Blood, etc. *:).* These little hooks can be regarded as a full set of notes upon the Practice of Medicine, containing the Synonyms, Definitions, Causes, Symptoms, Prognosis, Diagnosis, Treatment, etc., of each disease, and including a number of prescriptions hitherto unpub- lished. No. 4. PHYSIOLOGY, including Embryology. Seventh Edition. By Albert P. Brubakek, m.d.. Prof, of Physiology, Penn'a College of Dental Surgery ; Demonstrator of Physiology in Jefferson Medical College, Philadelphia. Revised, Enlarged, with new Illustrations. No. 5, OBSTETRICS. Illustrated. Fifth Edition. By Henry G. Landis, m.d. Edited by William H. Wells, m.d.. Assistant Demonstrator of Clinical Obstetrics, Jefferson College, Philadelphia. New Illustrations. BLAKISTON'S ? QUIZ-COMPENDS ? No. 6. MATERIA MEDICA, THERAPEUTICS, AND PRESCRIPTION WRITING. Fifth Revised Edition. With especial Reference to the Physiological Action of Drugs, and a complete article on Prescription Writing. Based on the Last Revision of the U S. Pharmacopoeia, and including many unofficinal remedies. By Samuel O. L. Potter, m.a., m.d., M.R.c.p (Lond.),late A. A. Surg. U. S. Army; Prof, of Practice, Cooper Medical College, San Francisco. Improved and Enlarged, with Index. No. 7. GYN.®COLOGY. A Compend of Diseases of Women. By Wm. H Wells, m.d., Ass't Demonstrator of Obstetrics, Jefferson Medical College, Philadelphia. Illustrated. No. 8. DISEASES OF THE EYE AND REFRACTION, including Treatment and Surgerj'. By L. Webster Fox, m.d.. Chief Clinical Assistant Ophthalmological Dept., Jefferson Med- ical College, etc., and Geo. M. Gould, m.d. 71 Illustrations, 39 Formulse. Second Enlarged and improved Edition. Index. No. 9. SURGERY, Minor Surgery and Bandaging. Illus- trated. Fifth Edition. Including Fractures, Wounds, Dislocations, Sprains, Amputations, and other operations; Inflam- mation, Suppuration, Ulcers, Syphilis, Tumors, Shock, etc. Diseases of the Spine, Ear, Bladder, Testicles, Anus, and other Surgical Diseases. By Orville Horwitz, a.m., m.d.. Demonstrator of Surgery', Jefferson Medical College. Revised and Enlarged. 98 Formulae and 167 Illustrations. No. 10. CHEMISTRY. Inorganic and Organic. For Medical and Dental Students. Including Urinary Analysis and Medical Chemistry. By Henry Leffmanm, m.d., Prof, of Chemistry in Penn'a College of Dental Surgery, Phila. Third Edition, Revised and Rewritten, with Index. No. II. PHARMACY. Based upon " Remington's Text-book of Pharmacy." By F. E. Stewart, m.d., ph.g. , Quiz-Master at Philadelphia College of Pharmacy. Fourth Edition, Revised. No. 12. VETERINARY ANATOMY AND PHYSIOL- OGY. 29 Illustrations. By Wm. R. Ballou, m.d., Prof, of Equine Anatomy at N Y. College of Veterinary Surgeons. No. 13. DENTAL PATHOLOGY AND DENTAL MEDI- CINE. Containing all the most noteworthy points of interest to the Dental student. Second Edition. By Geo. W. Warren, D.D.S., Clinical Chief, Penn'a College of Dental Surgery', Phila- delphia. Second Edition, Enlarged and Illustrated. No. 14. DISEASES OF CHILDREN. By Dr. Marcus P. Hatfield, Prof, of Diseases of Children, Chicago Medical College. Colored Plate. No. 15. GENERAL PATHOLOGY AND MORBID ANATOMY. By H. Newbery Hall, m. d., Lecturer on Pathology and Surgery Post Graduate School; Surgeon Emer- gency Hospital, Chicago, etc. Illustrated. Botmd is Cloth, $1. Isterleaved, for the Addition of Kotos, $1.25. . J|^* No series of books are so complete in detail, concise in language^ or so well printed and boufid. Each one forms a complete set of notes upon the subject laider con- sideration. Illustrated Descriptive Circular Free. 23,000 COPIES Of These Books Have Already Been Sold, GOULD'S NEW Medical Dictionary, Based on Secent Medical Literature. Small 8vo, Half Morocco, as above, wiih Thumb Index, , . $4.25 Plain Dark Leather, without Thumb Index, 3-25 A compact, concise Vocabulary, including all the Words and Phrases used in medicine, with- their proper Pronunciation and Definitions. "One pleasing feature of the book is that the reader can almost invariably find the definition under the word he looks for, without being referred from one place to another, as is too commonly the case in medical dictionaries. The tables of the bacilli, micrococci, leucomai'nes and ptomaines are excellent, and contain a large amount of information in a limited space. The anatomical tables are also concise and clear. . . . We should unhesitatingly recommend this dictionary to our readers, feeling sure that it wilt prove of much value to them." — Americati Journal of Medical Science. JUST PUBLISHED. GOULD'S POCKET DICTIONARY. 12,000 ; Medical Words Pronounced and Defined. ^. Leather, gilt edges, ^i.oo; with Thumb Index, ^1.25 UNIVERSITY OF CALIFORNIA LIBRARY Los Angeles This book is DUE on the last date stamped belo\t. I JUN 7fi£C^ fttOMED JUN 01*8$ ^fOMED LIB. JUN 1 6 1986 REC'D Form L9-40m-5,'67(H2161s8)4939 CARD EXPLANATORY OF J FOR COLOUR BL Test I. Confusion Colofrs. Red Blindness. v. Test II. a. o o o ■*=^ i oi I o I Green Blindness, "^ 9 Test II. b. Red Blindness. 10 11 ^reen Blindness. 12 13 N.B. — This Card is merelij intended to illustrate the text {(Jhaj). I. and Appendix I.), and not itself /or icse as a test.