MICHEL LOUTFALLAH THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA LOS ANGELES /t-/ THE DISEASES OE THE EYE THEIK MEDICAL AND SURGICAL TREATMENT. J. H. BUFFUM, M.D., O. et. A. Chir., PROFESSOR OF OPHTHALMOLOGY AND OTOLOGY IN THE CHICAGO HOM(EOPATHTC MEDICAL COLLEGE; OPHTHALMIC SURGEON TO THE CENTRAL DISPEN- SARY; FORMERLY RESIDENT SURGEON OF THE NEW YORK OPH- THALMIC HOSPITAL ; MEMBER OF THE AMERICAN INSTITUTE OF HOMOEOPATHY; MEMBER OF THE AMERICAN HOMCEOPATHIC OPHTHALMOLOGICAL AND OTOLOGICAL SOCIETY, ETC., ETC. ONE HUNDRED AND FIFTY WOOD ENGRAVINGS AND TWENTY-FIVE COLORED LITHOGRAPHS. f . p. JACKSON. M. D. 879 W. Vr Burm St. CHICAGO. CHICAGO: GROSS AND DELBRIDGE. 1884. COPYRIGHT, 1883, BY GKOSS & DELBBIDGE. R. R. MCCABE & CO., PnlXTEBS, CHICAGO. TO TIMOTHY F. ALLEN, A.M., M.D., PBO?ES5OB OP MATEBIA MEDICA AND THERAPEUTICS IN THE NEW YORK HOMtEOPATHIC MEDICAL COLLEGE, THIS BOOK IS DEDICATED, In grateful recognition of his masterly teachings, of his valuable contributions to Medical Science and Ophthalmic Therapeutics, and In remembrance of many acts of kindness. PREFACE. In the preparation of this work it has been the design of the Author to state as concisely and briefly as possible the present views of ophthalmic science. The endeavor has been to make the work practical and at the same time as thorough as the importance of the subject demands. The causes, symptoms, differential diagnosis, and treatment of those diseases which are more commonly met with in general practice have been fully considered. The methods of treatment described are those which have borne the test of hospital and private practice, and in the experience of the writer have been found of value. Numerous illustrations have been introduced to better elucidate the conditions and operations described, and such as are not original ha~e been selected from the standard works on ophthalmology, as well illustrating the points presented. Colored lithographs from the admirable atlas of Sichel and others have been added in the endeavor to more fully depict the diseases described and thus enable the student or practitioner to readily diagnose the various affections when presented. The brevity of the book has prevented reference in the body of the work to the authorities consulted in its preparation, and a list has been appended. A sheet of test types after the models of Snellen is furnished for the purpose of testing and recording the condition of the vision of patients. I desire to express my thanks to Dr. C. F. Bassett for assistance rendered in the preparation of the Index and the reading of proof. 90 Washington Street. CHICAGO, SEPTEMBEB, 1883. COKTEHTS. CHAPTER I. GENERAL ANATOMY AND PHYSIOLOGY OF THE EYE. PAGE. Anatomy Physiology Accommodation Visual Purple Binocular Vision, 1-19 CHAPTER IL METHODS OF EXAMINATION. General Examination Detailed Examination Test for Color Field of Vision Testing the Acuteness of Vision Range of Accommodation Focal Illumination Examination with the Ophthalmoscope Kinds of Ophthalmoscope Use of the Ophthalmoscope Ophthal- moscopic Appearances of the Normal Fundus Keratoscopy, - 19-41 CHAPTER III. GENERAL CONSIDERATIONS OF TREATMENT. Use of Anaesthetics Bandaging Eye Shades Hot and Cold Applica- tions Cleansing the Eye Mydriatics and Myopics Instruments, 41-50 CHAPTER IV. WOUNDS AND INJURIES OF THE EYE. Injuries of the Orbit Lids Lachrymal Apparatus Conjunctiva Cornea Solera Iris Lens Vitreous Choroid Retina, - - 50-64 CONTEXTS. CHAPTER V. EKROES OF REFRACTION. PAGE. Refraction Emmetropia and Ametropia Spectacles Range of Accom- modation Presbyopia Hypermetropia Hyperopia Myopia Astigmatism Anisometropia, - ... 64-101 CHAPTER VI. AFFECTIONS OF THE MUSCLES. Anatomy Diplopia Paralysis of the Ocular Muscles Muscular Asthenopia Strabismus Nystagmus, - - 101-130 CHAPTER VII. DISEASES OF THE ORBIT. Anatomy Orbital Cellulitis Periostitis Caries and Necrosis Capsn- litis Exophthalmic Goitre Tumors of the Orbit Diseases of the Cavities Surrounding the Orbit, - 130-150 CHAPTER VIII. DISEASES OF THE LACHRYMAL APPARATUS. Anatomy Dacryo-adenitis Lachrymal Strictures Dacryo-cystitis Dacryo-cysto-blennorrhcta, - 150-1G7 CHAPTER IX. DISEASES OF THE LIDS. Anatomy Blepharitis-acuta Erysipelas Hordeolum Chalazion Ble- pharo-adenitis Trichiasis Eutropium Canthoplasty Ectropium Tarsoraphy Blepharoplasty -Ptosis Paralysis of the Orbicularis Blepharospasm Anchyloblepharon Tumors, 167-196 CHAPTER X. DISEASES OF THE CONJUNCTIVA. Anatomy Hyperaemia Conjunctivitis Conjunctivitis Catarrhalis Ver- nal or Autumnal Conjunctivitis Atropine Conjunctivitis Conjunc- CONTENTS. IX PAGE. tivitis Purulenta Ophthalmia Neonatorum Gonorrhoeal Ophthalmia Croupous or Membranous Conjunctivitis Conjunctivitis Diphthe- ritica Conjunctivitis Trachomatosa Trachoma Follicular Conjunc- tivitis Conjunctivitis Phlyctenularis Pterygium Symblepharon Tumors, 196-235 CHAPTEB XL DISEASES OF THE CORNEA Anatomy Keratitis Phlyctenularis Keratitis Ulcerosa Corneal Ulcers Keratitis Diffusa: Non-vascular; Vascular Keratitis Suppurativa Corneal Opacities Staphyloma Corneas Kerato-cornus Kerato- globus Tumors, 235-262 CHAPTER XII DISEASES OF THE SCLERA. Anatomy Scleritis Episcleritis Sclerotico-Choroiditis Anterior Sclerotico-Choroiditis Posterior, 262-268 CHAPTER XIII. DISEASES OF THE IRIS. Anatomy Iritis Iritis Serosa Iritis Plastica Iritis Suppurativa Tumors Congenital Malformations Functional Diseases Mydriasis Myosis Operations, 268-291 CHAPTER XIV. DISEASES OF THE CILIARY BODY. Anatomy Cyclitis Irido-cyclitis Traumatic-cy clitis Functional dis- eases of the Ciliary Muscle Paralysis of the Accommodation Spasm of the Accommodation, 291-301 CHAPTER XV. SYMPATHETIC OPHTHALMIA. Sympathetic Irritation Sympathetic Inflammation Eneucleation Optico-ciliary Neurectomy and Neurotomy Use of Artificial Eyes, - ..... 301-311 X CONTENTS. CHAPTER XVI. DISEASES OF THE LENS. PAGE. Anatomy Cataract Lenticular Cataract Soft Cataract Zonular Cata- ract Cortical or Mixed Cataract Hard or Senile Cataract Opera- tions for Senile Cataract; Modified Linear Extraction Capsular Cataract Aphakia Luxatio Lentis, ... 311-341 CHAPTER XVII DISEASES OF THE VITREOUS. Anatomy Hyalitis Opacities Hemorrhage Cysticercns Persistent Hyaloid Artery, - ... 341-347 CHAPTER XVIII DISEASES OF THE CHOROID. Anatomy Hyperaemia Anaemia Choroiditis : Serosa; Plastica; Dissemi- nata Areolaris: Suppurative Sclerotico-Choroiditis Posterior Sarcoma Detachment Coloboma Albinism, 347-359 CHAPTER XIX. GLAUCOMA. Glaucoma Varieties Acute or Inflammatory Causes Symptoms Diagnosis Treatment Chronic Causes Results of Pressure Symptoms Diagnosis - - 359-372 CHAPTER XX. DISEASES OF THE RETINA. Anatomy Hyperaemia Anaemia Retinitis Retinitis : Albuminurica : Syphilitica; Pigmentosa: Proliferans Leucaemica Detachment of Retina Functional Diseases: Hyperaesthesia: Snow-Blindness: Nyc- talopia: Anaesthesia: Hemeralopia: Commotio Retinae: Hemiopia: Scotoma Color-BlindnessTumors, .... 372-393 CONTENTS. XI CHAPTER XXL DISEASES OF THE OPTIC NERVE. PAGE. Anatomy Diseases of the Optic Nerve Hyperaemia Neuritis Optica: Wooly Disc: Choked Disc: Neuritis Descendens Retro-bulbar Neuritis Optic Nerve Atrophy Amaurosis and Amblyopia Simulated Blind- ness Tumors of the Optio Nerve, - - 393-405 ILLUSTRATIOHS. FIGUBE. PAGE. 1. Diagram of a horizontal section of the right eye, - 3 2. Microscopical section of the Cornea, 5 3. Microscopical section of the Sclera, Choroid and Retina, 6 4. The Ciliary Nerves after removal of the Sclera, - 9 5. Diagramatic section of the eyeball showing the Blood-Supply, 10 6. The distribution of the Retinal Vessels, 11 7. The Venae Vorticosae and blood supply of the Iris and Ciliary body, 12 8. The whorls of the Venae Vorticosae. - 12 9. The formation of the image upon the Retina, - 14 10. Diagram of the changes in the eye during Accommodation, - 15 11. Diagram of the Field of Vision for Colors, 26 12. Diagram illustrating the theory of the Ophthalmoscope, - 29 13. Helmholtz's Ophthalmoscope, - 30 14. Liebreich's Ophthalmoscope, - 31 15. Loring's Ophthalmoscope, 32 16. Knapp's Ophthalmoscope, - - 33 17. Diagram illustrating the use of the Ophthalmoscope in the indirect method, 36 18. Ophthalmoscopic appearance of the Optic Disc, - 37 19. Liebold's Subpalpebral Syringe, 45 20. Atropine dropper, - - 46 21. Desmarre's lid-retractors, 47 22. Noyes' eye-speculum, - 48 23. Liebold's eye-speculum, - 48 24. Fixation forceps, - 48 25. Beer's Cataract-knife, 49 26. Sharp gouge, - 54 27. Spud, 54 28. Detachment of the Iris, - 58 29. Knapp's foreign-body hook, 62 30. Gruening's magnet, - : 63 31. Diagram of the refraction of parallel rays of light on passing through a convex lens, - 64 ziii XIV ILLUSTRATIONS. FIGUBE. PAGE. 32. Diagram illustrating the law of conjugate foci, - 65 33. Diagram illustrating the refraction of parallel rays of light on pass- ing through a concave lens, - Go 34. Diagram showing the relation of the visual and optic axes, the angle alpha, and the nodal point of the lens system of the eye, - 65 35. Diagram showing the relative length of the hypermetropic, emmetro- pic and myopic eye, - 67 36. Sections of spherical glasses, - 70 37. Diagram illustrating the action of the accommodation upon divergent rays of light which enter the eye, - 71 38. Diagram illustrating the correction of hypermetropia by the use of a convex glass, - 81 39. Section of a myopic eye, 86 40. Ophthalmoscopic appearance of the choroidal crescent in myopia, 87 41. Circular atrophy of the choroid around the disc in myopia, - 87 42. The correction of myopic refraction by the use of a concave glass, - 91 43. Test-card for determining astigmatism, 97 44. Muscles of the eyeball, 102 45. Diagram illustrating the production of direct diplopia, 105 46. Diagram illustrating the production of crossed diplopia, - - 106 47. Dot-and-line for determining insufficiency of the recti muscles, 115 48. The Strabismometer, 120 49. Curved strabismus scissors, 123 60. Strabismus forceps, - 123 51. Strabismus hook, 123 52. Operation for Strabismus Convergens, - 124 53. Needle forceps, - 125 64. The bony orbit, 131 55. Diagram of the canaliculi and lachrymal sac, - 151 56. Dissection showing the opening of the nasal duct beneath the inferior turbinated bone, 151 57. AnePs canaliculus probes, - - 154 58. Weber's canaliculus knife, 155 59. Passage of the lachrymal probe, - 157 60. Stilling's knife for lachrymal strictures, - 158 61. Bowman's lachrymal probes, - 159 62. Weber's conical lachrymal probe, 159 63. Williams' bulbous pointed probes, - 159 64. Mucocele, - 164 65. Diagramatic section of the upper lid, - 168 66. Clamp forceps for lid operations, 173 67. Knapp's entropium forceps, - - 174 68. Cilia forceps, 181 69. Horn spatula for lid operations, - 182 70. Operation of transplantation of the cilia, 182 71 and 72. Entropium, - 183 73 and 74. Hotz's operation for entropium, 18;- ILLUSTRATIONS. XT FIOUBE. PAGEU. 75. Canthoplasty, - 186- 76. Ectropium, 18ft 77 and 78. Wharton Jones' operation for ectropium, - 187 79 and 80. Adam's operation for ectropium, 187 81 and 82. Diffenbach's operation for ectropium, - - 188 83 and 84. Operation of Tarsoraphy, - 188-189 85. Arlt's blepharoplasty operation, - 189 86. .Knapp's operation for Blepharoplasty, - 190 87. Granulations of the conjunctiva granular lids, - - 220- 88-89-90. Teale's operation for symblepharon, 233 91. Microscopical section of the cornea, - 236 92. Desmarre's paracentesis knife, - 246- 93. Broad eye-needle, - 246. 94. Weber's beak-pointed canaliculus knife, . 246 95 and 96. The notched teeth of Hutchinson, - - 250- 97. Tattooing-needles, 258 98. Conical cornea, - 260 99. The muscular fibres of the Iris, - 269 100. Straight keratome, - - 286 101. Angular keratome, 286- 102. Linear cataract-knife, - 286- 103. Angular Iris-forceps, 286 104. Straight Iris-scissors, - 287 105. Curved Iris-scissors, 287 106. Iridectomy incision of the Cornea, - 288- 107. Iridectomy cutting of the Iris, 288 108. Iridectomy appearance of the coloboma when the section is made outward, - - 289 109. Iridectomy appearance of the coloboma when the section is made upward, 289 110. Liebold's Iris-scissors, - 289 111. Artificial eye, 308 112. Soft cataract under focal illumination, - 315 113. Soft cataract with irregularities in its substance, 315 114. Operation of Discission, - 317 115. Operation for Linear Extraction, 318 116. Removal of the lens-matter through the incision, - 319 117. Section of a Zonular Cataract showing its lamellar opacity, - 319 118. The appearance of Zonular Cataract under focal illumination, - 320 119. The same when viewed by the transmitted light of the ophthalmo- scope, - 321 120. Section of a Cortical Cataract, - 321 121. The appearance of Cortical Cataract when viwed by the ophthalmo- scope, 321 122. The same when examined by focal illumination, - 321 123. Section of a Hard or Nuclear Cataract, 322 124. The appearance of Hard Cataract when viewed by focal illumination, 323 XVI ILLUSTRATIONS. FIGURE. PAGE. 125. Hard Cataract when examined with the ophthalmoscope, 323 126. Incision in Flap operation for Cataract, - - 330 127. Incision in Graefe's Modified Linear operation, 330 128. LeBrnn's and Liebrich's Incisions, - - 330 129. Von Graefe's Operation for Cataract, - 331 130. Fixation Forceps, - - 333 131. Linear cataract knife, - - 334 132. Hard rubber, or silver, Lens scoop, - ;)34 133. Angular Iris-forceps, - 334 134. Curved Iris-scissors, - 335 135. Cystotome, 335 136. Fenestrated Wire Lens Scoop, - - 336 137. Line of the various incisions of the cornea for Cataract Extrac- tion, - - 337 138. Posterior Polar Cataract, - - 338 139. Pigment and Stroma cells of Choroid, - 348 140. Section of Eye showing whorls of Venae Vorticosae, - 348 141. Ophthalmoscopic appearance of fundus in Choroiditis Dissem- inata, 353 142. Section of Optic Nerve showing the Glaucomatous cupping, - 364 143. Ophthalmoscopic appearance of Glaucomatous Cup, 365 144. Line of sections of the Cornea in Iridectomy and Sclerotomy, - 370 145. Injection of the capillary Vessels of the Macula Lutea, 373 146. Diagramatic Section of the Retina, - - 373 147. Hexagonal pigment cells of the Retina, 374 148. Section of the Eye, showing Detachment of the Retina, - - 384 149. Ophthalmoscopic appearances of Detachment of the Retina, - 385 150. Section of the Optic Nerve and the appearance of the Optic Disc, - - - - - - - - 394 BIBLIOGRAPHY. Graefe and Saemisch: Handbuch der gesammten Augenheilkunde. Stellwag: Treatise on Diseases of the Eye. Soelberg V.'ells: Treatise on Diseases of the Eye. Schweigger: Handbuch der Augenheilkunde. Carter: On the Eye. Macnamara: Diseases of the Eye. Nettleship : Diseases of the Eye. Donders: Accommodation and Refraction. Alt: The Human Eye. Mittendorf : Diseases of the Eye and Ear. Gowers: Medical Ophthalmoscopy. DeWecker: Ocular Therapeutics. Albutt: The Ophthalmoscope. Galezowski: Traite des Maladies des Yeux, Landolt: Examination of the Eyes. Noyes: Diseases of the Eye. Knapp: Archives of Ophthalmology. Royal London Ophthalmic Hospital Reports. Norton: Ophthalmic Therapeutics. Many smaller works, Monographs and Journals. AND INJURIES OF THE EYE. CHAPTER I. GENEEAL ANATOMY AND PHYSIOLOGY. To comprehend the various changes which result from disease or injury to the eye, a full knowledge of the anatomy and physiology of this organ becomes necessary. Without it, a proper appreciation of the value of the pathological changes which may result, in either a medical or surgical sense, is impossible. Hence, a review of the general anatomy of the eye, at this time, will be followed by a more detailed descrip- tion of the histology of the separate portions in the various chapters, according to their importance. ANATOMY. The human organ of vision consists essentially of a hollow sphere into which the light vibrations are conducted through its anterior transparent portion and its refractive media, to fall upon the percipient elements in the expansion of the optic nerve upon the interior. For visual perception the eyeball with its contents alone is necessary; but connected with it are muscles, nerves, blood-vessels, and other parts especially designed for its nutrition and protection. The eyeball is suspended in the pyramidal cavity of the orbit at an equal & DISEASES AND INJURIES OF THE EYE. distance from its walls, and rests upon a cushion of loose fat and connective tissue, from which it is separated by a fibrous expansion the capsule of Tenon. It is freely movable in every direction about its center of rotation in this mem- branous socket by the muscles inserted into its outer coat. Through its capsule, its vascular and lymph supply, and the optic nerve, it is in direct communication with the brain and its membranes. It is thoroughly protected from external injury by the strong, bony margin of the orbit, the eyelids and their cilia and the delicate mucous membrane covering it externally. This membrane is also reflected upon the eyelids, forming a soft and moist membrane, necessary to preserve the transparency of the anterior part of the globe. This mem- brane, the conjunctiva, is continuous through the lachrymal canals with that of the nasal cavities, and with the integument of the face at the margin of the eyelids. Its moisture is derived from the secretions of its own glands and also from the lachrymal gland which is lodged in the upper and outer angle of the orbit, and sends numerous ducts to open upon the internal surface of the outer part of the upper lid. The conjoined secretions, after passing over the conjunctiva, are received by the two puncta lachrymalia at the inner canthus, .or angle of the lid, which open into minute horizontal canals, the canaliculi. These carry the tears to the lachrymal sac, from which they pass directly to the nose through the lach- rymal and nasal ducts. The eyeball, while presenting a globular or spherical form, is really formed by the union of portions of two hollow spheres of different diameter, of which the anterior and more promi- nent segment is the smaller ; the segment of the larger opaque surface corresponds with the limit of the sclerotic portion, and the translucent portion of the smaller sphere with that of the Cornea. The antero-postenor diameter, or axis of the eyeball js a line drawn perpendicularly through the centre of the cornea to the sclerotic, and measures about .95 of an inch, or 24.3 mm. in length. Its transverse diameter is a horizontal line drawn perpendicular to its axis at the centre of the eyeball ANATOMY. and measures .93 of an inch, or 23.6 mm. The vertical diam- eter is a line drawn at right angles to both these lines at the centre, and gives a length of .92 of an inch, or 23.4 mm. The anterior pole of the eye is the geometric centre of the \ / - \^=f^J FIG. 1. cornea, the posterior pole being the centre of the back part of the globe. The o-ptic axis is the line connecting these two points. The visual axis is an imaginary line drawn from the object looked at to the macula lutea, the visual centre of the retina, and cuts the cornea slightly above and to the inner side 4 DISEASES AND INJURIES OF THE EYE. of the optic axis. The equator is the circle passing around the eye midway between the two poles. The meridians of the eye are circles formed by planes passing through the centre of the eyeball, the two principal meridians being the horizontal and the vertical. The eyeball is composed of several investing tunics, enclos- ing fluid and solid contents, called the refracting media. The tunics, or investing membranes, are three in number, viz: an external fibrous membrane forming the Cornea (C Fig. 1) and Sclera (S) ; a middle vascular and partly muscular mem- brane, the Choroid (C7i) Ciliary body (Pc) and Iris (J), and an internal nervous stroma, the Retina (R). The enclosed refracting media are the Aqueous humor (^.c), the Lens (-/), and Yitreous (VB), the most important being the crystalline lens, which is a double convex body enclosed in a transparent capsule and situated immediately behind the pupil. It is. retained in position by a suspensory ligament, the zonule of Zinn (ZZ), which connects its periphery with the anterior margin of the retina and the ciliary processes. The space between the anterior portion of the lens and the posterior surface of the cornea is filled with the aqueous humor and is divided by a movable partition, the iris, into the anterior (Ac) and posterior (Pc) chambers. The Vitreous ( VB) which occupies about four-fifths of the eyeball posteriorly, fills the cavity behind the lens and consists of an albuminous fluid inclosed in a delicate membrane, the hyaloidea. The Sclerotic (S~Fig. 1), having a thickness of nearly 1-25 of an inch or from .7 to .9 mm. is a strong, opaque, unyielding, fibrous structure which maintains the form of the eye and gives support to the delicate interior structures, and allows of the entrance and exit of nerves and blood-vessels which supply the parts within. It extends over about five-sixths of the eyeball, joining in front with the cornea. The outer surface is white and smooth except where the tendons of the recti and oblique muscles are inserted into it. About 1-10 of an inch to the inner or nasal side of the posterior pole of the globe, is an opening, partially closed by a sieve-like membrane, the ANATOMY. lamina cribrosa (c), 1-13 of an inch, or 2 mm. in diameter, for the entrance of the fibres of the optic nerve (ON]. The sclera is thickest behind; thinnest about 1-4 of an inch or 6 mm. from the cornea and thicker again at its junction with, the latter. Its blood supply is very slight, and derived from the ciliary vessels. It is largely deficient in nerves. The Cornea ( (7) forms the anterior one-sixth of the external coat, and presents a thickness of about 1-28 of an inch, or .9 mm. at its apex, and 1-22 of an inch, or 1.2 mm. at its margin. It is a perfectly transparent, highly polished membrane, ,and having a shorter radius projects from the sclera, and admits the light to the inte- rior of the eye. It presents an ellipsoidal shape, having jl its horizontal diameter rather - . longer than the vertical, ow- ing to the overlapping of the sclera, of which it is a mod- ified continuation. It con- sists of five layers (Fig. 2) : an outer layer of epithelium (1) continuous with the con- junctiva, a thin structureless membrane (2), a thicker central layer or true corneal tissue (3), a posterior elastic membrane (4), and upon the latter a layer of endothelium (5). The cornea has no blood- vessels except at its margin, and is nourished by endosmosis from these capillary vessels. Its nerve supply is very abun- dant and is derived from the ciliary nerves. The Canal of Schlemm (Sc Fig. 1) is a circular venous sinus which surrounds the anterior portion of the eye. It is situated in the sclerotic, close to its junction with the cornea. A minute open space has been traced from it into the anterior FIG. 2. O DISEASES AND INJURIES OF THE EYE. chamber (AC] from which, it is separated by the ligamentum pectinatum. It forms the exit from the anterior chamber of the aqueous fluid which is derived from the vessels of the iris and ciliary processes. Upon the patency of this canal depends- the condition of the intra-ocular tension. The Ckoroid (Ch Figs. 1 and 3) is a dark, brown membrane 1-300 to 1-150 of an inch in thickness, lying between the scler-a and the retina. It consists almost entirely of blood- vessels united by a delicate connective tissue, and forms the nutrient membrane for the lens and vitreous. It is loosely attached to the solera, except where the optic nerve is transmitted, and reaches forward nearly to the cornea, where it ends in a series of folds or plaits, seventy in number, called the ciliary processes, where it again becomes more firmly attached to the sclera. In the choroid, four layers are described. Externally and resting upon the inner surface of the sclera, is a loose connective tissue con- taining branching black and brown, pigment cells surrounding the vessels and nerves which pass from behind forward to supply the iris and ciliary body. Owing to its loose attachment to the sclera, a minute space (Pch Fig. 3) is left which is lined by endothelium and forms a lymph space, which connects with Tenon's space about the exit of the veins of the choroid where they pierce the sclera. The second layer consists of larger branches of the ciliary arteries and whoii- like veins, the venae vorticosse (VV Fig. 1), which, passing deeper and becoming smaller, form the third layer, or layer of capillary vessels. The fourth layer consists of a minute structureless limiting membrane which gives the smooth inner surface to the choroid, and is covered by the hexagonal pigment cells of the retina. The Ciliary processes (Pc Fig. 1), about seventy in number, ANATOMY. 7 are formed by the folding of that portion of the choroid which lies anterior to the equator of the globe, the pigment layer of the retina being continued forward as a covering. These processes are arranged radially together in the form of a circle. They consist of larger and smaller folds, without regular alternations, the small folds being in number about one third that of the larger. Into these folds of the ciliary processes, fit corresponding plications of the suspensory liga- ment of the lens. The Ciliary muscle, the muscle of accommodation, is a circular band of involuntary muscular fibres which take both a circular and meridional course. This muscle underlies the ciliary processes and they together form the Ciliary body. The fibres of the ciliary muscle arise from a tendinous ring at the inner side of the canal of Schlemm. The meridional fibres pass backward and are lost in the tissue of the choroid, while the circular fibres form a sphincter or ring muscle. The ciliary body is largely supplied with vessels and nerves. The Iris (I Fig. 1) is the contractile and colored membrane, which is seen behind the transparent cornea and gives the tint to the eye. It is a movable muscular curtain, with a central perforation, the pupil, which regulates the amount of light admitted to the eye. The iris measures about one-half an inch across, and in a state of rest about one-fifth of an inch from the circumference to the pupil. The iris consists of a loose stroma of connective tissue, containing muscular fibres, blood vessels, nerves and pigment cells, and may be regarded as a process of the choroid, with which it is continuous. The pigment layer of the retina is continued forward upon the posterior surface of the iris. Immediately beneath this are muscular fibres of the iris which take a radial course at the periphery, the dilator of the pupil, while at the pupillary margin are seen the circular fibres of the sphincter muscle of the pupil. The blood supply is derived from the ciliary body, the nerves coming from the third, fifth, and sympathetic. The anterior surface is variously colored in different eyes, and is marked by waved lines converging towards the pupil, while 8 DISEASES AND INJURIES OF THE EYE. at the pupillary margin, the surface is drawn into minute concentric folds. The anterior surface is covered by irregular endothelial cells continuous with those of the posterior layer of the cornea. The Retina (R Figs. 1 and 3) is the delicate transparent expansion of the optic nerve, extending as far forward as the ciliary processes, where it terminates by an irregular margin, the Ora Serrata [OS]. From this border a thin layer of laminated cells is continued with the pigment layer forward on to the ciliary processes, and forms the ciliary portion of the retina. It lies within the choroid and rests upon the hyaloid membrane of the vitreous. The thickness of the retina diminishes from behind forwards, varying from 1-50 to 1-200 of an inch. It is made up of some ten layers, four of which may be considered of importance. The most external layer is that of the hexagonal pigment cells upon the surface of the choroid; arranged vertically upon this is a layer of rods and cones which cover the expansion of the retina, being more closely aggregated at the macula lidca which has in its centre a depression or the fovea centralis (Fc Fig. 1 ) where only cones are found. The rod and cone layer presents a delicate coloring matter, the retinal purple, which is formed by the pigment layer. The internal layer of the retina consists of the expan- sion of radial fibres of the optic nerve, the larger portion of the fibres sweeping towards the temporal side about the macula lutea. Between these external and internal layers are the remaining layers, consisting of ganglionic cells, granules and fibres which connect the percipient elements with the conducting filaments. The blood supply of the retina is mainly from the central artery of the nerve, the most external layers being nourished by osmosis from the choroid. The Optic nerve (ON Fig. 1) arises in the brain from two roots having their origin in the gray matter of the occipital lobes, intimately connected with the corpora geniculata, optici thalami and corpora quadrigemina, which receive fibres from other portions of the brain and spinal cord, and run forward as the optic tracts until they unite to form the optic chiasma, ANATOMY. 9 In which they decussate and turn off. to either side, each tract sending fibres to supply the inner half of the opposite eye, the greater portion, however, passing directly to the outer half of the retina of the same side. Some fibres have also been traced as passing from one eye to the other. The optic nerves proper as they emerge from the optic foramina are covered by a delicate neurilemma which is continuous with the pia mater and forms the pial sheath. More externally is a dense fibrous sheath continuous with the dura mater. These sheaths are joined together by a loose connective tissue and form a lymph space, the inter-vaginal, extending up to the sclera, which is in direct connection with the arachnoidal space of the brain. The nerve in the orbit is about one and one-eighth inches long and passes forward to enter the eye through the scleral ring, a little below and to the inner or nasal side of the posterior pole of the ball. It is made up of a large number of bundles of medullated fibres, which as they pass through the perforated opening in the sclera, leave their sheaths behind and radiate from the disc in all directions. The optic disc or papilla is the point of entrance of the optic nerve. The central artery of the retina (e Fig. 5) enters the nerve fifteen to twenty mm. behind the eyeball, and passing to the center of the nerve runs forward to appear upon the disc (Fig. 6), where it divides, usually, into two or more branches, which ramify through the inner layers of the retina. The nerves of the eye in addition to the optic, are the third, fourth, ophthalmic division of the fifth, and the sixth. The third is a motor nerve and supplies the superior, inferior and internal recti, inferior oblique, the levator palpebrse and ciliary muscles, together with the sphincter of the iris. It also sends a branch to the ciliary ganglion. The fourth nerve supplies the superior oblique, and the sixth the external rectus. The fifth sends sensory branches to the lids and conjunctiva, two to three long ciliary nerves to the eyeball, 10 DISEASES AND INJURIES OF THE EYE. and furnishes a sensory root to the ciliary ganglion. The ciliary ganglion is a minute flattened lenticular body which lies deep in the orbit between the optic nerve and external rectus muscle. It has motor, sensory, and sympathetic roots. From its anterior border several branches are given off which divide into fifteen or twenty, the short ciliary nerves, and these together with the long ciliary nerves from the third nerve, pass along the optic nerve sheath and pierce the solera around the optic nerve entrance. The ciliary nerves (Fig. 4) pass directly to the inner surface of the solera and advance to the ciliary body where a plexus is formed which supplies the iris, ciliary muscle, choroid, cornea and blood-vessels. The blood supply of the eyeball is divided into three systems: First, the short or posterior ciliary arteries (aa Fig. 5), which are derived from the ophthalmic, and consist of some twenty branches which pass through the sclerotic around the optic nerve entrance and supply the choroid together with the long ciliary arteries (6 Fig. 5), two in number, having the same origin as the others, which perforate the solera in front of the short, one on the nasal and the other on the temporal side, and then pass forward to form the complex vascular system of the anterior portion of the choroid, ciliary body and iris. Second, the anterior ciliary arteries (c Fig. 5) which, ANATOMY. 11 arising from the muscular branches, pass through the tendons of the recti muscles, pierce the selera at four to six mm. from the cornea, and passing forward form the arterial loops in the margin of the cornea (t 1 ), and supply the ciliary body (r), the iris (g) and anterior parts of the selera (w). They become visible to the naked eye only in inflammation of these parts. Third, the central artery of the retina (e Fig. 5, Fig. 6), which enters the optic nerve about 15 to 20 mm. behind the eyeball, and passing to its centre emerges upon the optic papilla and there divides into two branches, one above and one below. These again dividing and arching out, supply the inner layers of the retina, leav- ing the portion occupied by the j macula lutea comparatively free. ( See Fig. 6 ) . The veins of ih& cornea, iris and ciliary body follow closely the arrangement of the arteries, but in the choroid after numerous ramifi- cations and anastomoses they unite into large whorls, the venae vorticosse (v Fig. 7 and 1 Fig. 8), which are four to six in number and have large trunks which pass out through the selera near the equator, and carry off the major portion of the blood from the uveal tract. There are no -veins corresponding to the long ciliary arteries. The venous blood from the eye is emptied through the superior and inferior ophthalmic vein into the cavernous sinus. The lymphatic system of the eyeball is necessarily complex and extensive, from the fact that were blood-vessels used to carry the product they would interfere with distinct vision by lessening the transparency of the various tissues. Hence, the circulation of the nutrient fluid, in the form of colorless lymph, is carried on through these channels. Upon the interruption or rapidity of this flow depends the tension, or fluid pressure, FIG. 6. 12 DISEASES AND INJURIES OF THE EYE. of the eyeball. The lymph formed in the different tissues of the eye, after having nourished the parts for which it is intended, passes out through three different channels, the canal of Schlemm, the spaces around the choroidal veins, and through the optic nerve. That formed in the anterior portion of the eyeball being principally derived from the iris and ciliary body ; that secreted by the ciliary body, after supplying the vitreous and posterior layers of the lens, finds its way through minute openings in the zonule of Zinn. (ZZ Fig. 1) into the posterior chamber, where it is increased by that ria. 8. na. 7. coming from the iris and thence passes into the anterior chamber between the iris and lens; the iris in its normal condition being so applied to the lens as to prevent any reflux into the posterior chamber, it mingles with the secretion from the anterior surface of the iris and, in part, from the mem- brane of Descemet and cornea. This commingled fluid finds an exit through the meshes of the ligamentum pectinatum at the angle of the iris into the canal of Schlemm (So Fig. 1), where it meets the lymph which has been used in nourishing the cornea, and passes out into the anterior ciliary veins, (c' Fig. 5). There is an unexplained resistance upon the part of the lymphatics which retards the flow sufficiently to preserve a proper tension of the fluid in the anterior chamber. The lymph formed in the choroid and sclera passes into the space between these membranes (Pch Fig. 3) which exists in the loose trabecular tissue formed by the supra-choroidea and PHYSIOLOGY. lamina fusca, which connect the two tunics, and which presents lamellae covered by endothelial cells; around the trunks of the venae vorticosse (h Fig. 5) as they pass out through the sclera at the equator lymph sheaths have been described which communicate with Tenon's space, the lymph space between the outer surface of the sclera and inner surface of the capsule of Tenon, which extends along the optic nerve and thus gives exit to the lymph from the choroid and sclera to the arachnoidal cavity of the brain, through the canalus opticus. The third mode of exit, that for the lymph from the retina and inner portions of the optic nerve, is by canals around the blood-vessels, particularly the capillaries and veins passing out through the lamina cribrosa. The lymph space of the optic nerve will be considered in the chapter devoted to the discussion of its anatomy and diseases. PHYSIOLOGY OF THE EYE. Bays of light falling upon the retina cause what is termed a sensation of light, but to obtain distinct vision of any object an image of that object must be formed on the retina. These rays of light impinging upon the retina, give rise to sensory impressions through some excitation of the nerve terminations in the retina. This excitation is accomplished by the mechan- ical irritation due to the vibrations of the luminous rays, to changes in the electric currents of the nerves, to chemical decomposition of certain matters in the retina, and to changes in the temperature due to the rays. These sensory impulses transmitted along the optic nerve through certain portions of the brain, and possibly modified in their passage, affect our consciousness and become sensations. Luminous rays of light, passing through a bi-convex lens, which is a lens with two convex surfaces, are brought together at a point on the opposite side of the lens. These rays if they proceed from a luminous object, as a candle, diverge, and, fall- ing upon the bi-convex lens, are again converged by it and DISEASES AND INJURIES OF THE EYE. brought to a focus at a point behind it; if, now, a screen is placed at this point, an inverted image of the candle will be formed upon it. The eye may be considered as equal to a bi- convex lens of |- of an inch or 22.65 mm. focal length by which inverted images as in Fig. 9 are formed upon the retina as a screen. Impressions made on the perceptive elements, cause local changes, the effect of which, when transmitted to the brain, is projected outwards in an inverted direction to the object, thus making us conscious of the existence of the form and posi- tion of objects, although in reality we only see the inverted images of them. Again, the fact that we see the image in its proper position, instead of inverted, is explained on the hy- pothesis that each cone conveys its own portion of the retinal image to the brain. For the formation of an image upon the retina, a F1G - 9 - dioptric appar- atus is provided. This consists of a series of curved refracting surfaces and media, which are sufficient to bring rays of light to a focus upon the retina, and thus produce a well-defined image. These refractive media being transparent the rays of light enter the outer surface of the cornea, pass through the cornea, the aqueous, the lens and the vitreous. The cornea, aqueous and vitreous have the same refractive power or index, and the lens, although not possessing the same refractive power throughout, yet, owing to the difference in the density of its central and outer layers, may be considered as having a refrac- tive power equal to the mean of the sum of its refractive parts. 'Thus, for the purpose of demonstration, the natural eye, instead of presenting these several refractive surfaces and media, is re- duced to a "diagrammatic eye" in which the refracting surfaces are reduced to three, viz. : (1) The anterior surface of the cornea. (2) The anterior surface of the lens, separating the aqueous from the lens. (3) The posterior surface of the lens, separating the lens from the vitreous. The media are similarly reduced to A CCOMMODA TION. 15 two: the mean index of the lens, and the aqueous or the vitreous. This diagrammatic eye becomes of great value in studying physiological optics where the calculations deduced represent those of the natural eye with sufficient accuracy for practical purposes. The calculated position of the principal posterior focus, that is, the point at which all rays falling upon the cornea parallel to the optic axis are brought to a focus, is in the diagrammatic eye 14.647 mm. behind the posterior surface of the lens, or 22.647 mm., about 23. mm., behind the anterior surface of the cornea. The fovea centralis, the point of most acute vision of the retina, must occupy this position in order that a distinct image of a distant object may be formed upon it. The values given in these calculations, however, refer to the eye when in a condition of rest and not in any effort of accommodation. ACCOMMODATION. Parallel rays of light entering the normal eye when it is in a state of rest, are brought to a focus upon the retina; light- rays coming from an object over twenty feet distant being sufficiently parallel for all practical purposes. If, now, these rays are ren- dered diver- gent, or the ob j e c t is brought nearer to the eye, the rays no longer form an image upon the retina, but at some distance behind it, as the focal power of the eye, in this condition, is not enough to bend the rays of light sufficiently to bring them to a point upon the retina; hence, for the purpose of producing a well-defined image upon the retina, when an object is within an infinite distance, the eye possesses the power to adjust itself for 16 DISEASES AND INJURIES OF THE EYE. this distance. This power is termed the function of accom- modation and enables the eye to focus near objects distinctly. This is accomplished by an increase in the convexity of the crystalline lens (A Fig. 10), chiefly on its anterior surface, whereby it becomes a lens of shorter focus (B Fig. 10). The lens is elastic and by reason of a peculiar arrangement of its fibres constantly tends to assume a more convex shape. The degree of convexity is controlled by the tension of its suspensory ligament, the zonule of Zinn, acting upon its capsule. In the act of looking at a near object the ciliary muscle contracts and bringing the ciliary processes closer together the zonule is relaxed, and the lens becomes at once more convex from its own elasticity. This elasticity dimin- ishes from infancy with a corresponding diminution in the power of accommodation, until at forty years of age it becomes difficult to focus for a near point for minute objects. During the act of accommodation, which is an involuntary one, certain other changes in the eye take place, and the whole act may be summed up as follows: the pupil contracts, cutting off the more diverging rays, the front of the lens becomes more convex, and, advancing somewhat, carries the iris forward with it; the posterior surface of the lens changes slightly, its edges becoming rounded; the ciliary body increases in size and projects somewhat nearer to the centre of the eye. The main factor in the production of this adjustment of the eye is the ciliary muscle, the ring muscle of the ciliary body, which on contracting becomes thicker, causing a swelling of the ciliary body, and a movement of this process inward, thus relaxing the suspensory ligament. The eye is by no means a perfect optical apparatus, but presents many defects owing to the curves of its surface not being perfectly spherical, thus producing a diffusion of the image from spherical aberration, or there may be a want of symmetry in the curves, as in astigatism. The media also are not perfectly transparent, and shadows of these imperfections are thrown upon the retina, presenting what is termed entoptic phenomena. VISUAL PURPLE. 17 The region of most distinct vision is the macula lutea, and it is at this point that the images are focused upon the retina. Although all other portions of the retina are sensitive to light impressions, the images diminish in distinctness as they are removed from the yellow spot. The images of surrounding objects which are visible when the eye is fixed in any direction constitute the field of vision. The region of distinct vision is limited, however, to the macula lutea where only cones are present as terminal elements of the nerve structure of the retina. The optic nerve entrance, being entirely destitute of the rods or cones, presents a blind spot, or scotoma, in the field of vision, thus proving that the optic nerve fibres them- selves are insensible to light. The size of this blind spot depends upon the distance of the field of vision from the eye. At eighteen inches, it amounts to the area of a circle of one inch in diamter. At the distance of the moon, this scotoma covers a field equal to thirteen diameters of the moon. To demonstrate this loss in the field of vision the experiment of Mariotte is employed. A cross is made on a sheet of paper, and 2f in. to the right, is drawn a black disc in. in diameter. Closing the left eye, the right is directed at the cross held about one foot away. On moving the paper to and from the eye, the disc will, at a certain distance, become invisible. VISUAL PURPLE. The discovery by Boll, sustained by the later investigations of Kuhne, that the rods of the retina were surrounded by a secretion from the hexagonal pigment cells of the retina, of a purple or rose color, which is formed in darkness and decom- posed in sunlight, was supposed to determine the photo- chemical theory of light perception that the images of objects were impressed upon the retina by the decomposition of this coloring matter, and the fact that these images could be so fixed upon the retina as to be copied after death, seemed to add weight to this theory of the origin of visual impulses. The discovery, however, that the rods were the active agents 2 18 DISEASES AND INJURIES OF THE EYE. in the secretion of this matter, and its total absence from the central part of distinct vision, the macula lutea, where only- cones are present, shows that further investigation will be required to determine its true function. BINOCULAR VISION. Though we have two eyes, the fact that we have binocular vision, or single sight, is due to the reception of the image upon symmetrical portions of the two retinas, which contain cones, the centers of which are probably centrally asso- ciated in the brain. To effect binocular vision, both eyes converge equally upon the object, and images are formed upon identical portions of the retina. These images blended in the brain give us, not only size and direction, but also relief, or the idea of solidity, of the object. With monocular, or vision with a single eye, we get only an idea of the size and direction, but not of the solidity of the object. If the images do not fall upon identical or corresponding portions of the retina, as the fovea, then two objects are seen, and double vision, or diplopia, results. CHAPTER II. METHODS OF EXAMINATION. GENEBAL EXAMINATION. "With a systematic mode of examination of eye patients, the surgeon quickly acquires the habit of rapidly diagnosing some eye affections from external appearances, thus rendering the result of complete inquiry into the full condition less liable to error. The history and symptoms of disease or injury of the eye are often necessary in the formation of a diagnosis, and should be supplemented by a personal and careful inspection of the eye and its appendages, before formulating an opinion or proceeding to treatment. A glance at the appearance and bearing of the patient may enable us, in some cases, to decide upon the part affected, and confirm the diagnosis by further examination. A person having lost vision from some retinal or optic nerve affection carries his head well up and eyes open; the cataract patient shades the eyes with the hand and advances more timidly. The astigmatic patient carries the head to one side, or with the lids half closed, as in myopia, or with the head bent forward and the eyes directed upwards towards the eyebrows, as in paralysis of the superior oblique muscle, where vertigo follows the attempt to look downwards. The half-closed eyes of one suffering from ptosis, or the trachomatous patient with his heavy lids, or again the patient suffering from some corneal or conjunctival affection where intense photo- 19 20 DISEASES AND INJURIES OF THE EYE phobia requires covering the eyes to exclude all light, indicate the part affected and the probable diseased condition. DETAILED EXAMINATION. For the purposes of examination, the patient should be seated before a window which admits a clear, but not too bright light; the surgeon stands at the side, or if necessary to confine the head of the patient, a towel having been thrown over it, it is supported against the chest of the sur- geon, who stands behind. In young children or infants, the body and limbs of the child should be held in the lap of an attendant while the head rests between the knees of the surgeon. If the eyes are sensitive to light and painful, or the patient so nervous as to interfere with a proper exam- ination, it is necessary to administer an anaesthetic, as a complete inspection must be obtained. In a general survey, we are obliged to determine by comparison of the two eyes whether one or both are affected ; the presence or absence of squint, or loss of mobility of the eyes from paralysis of the muscles or the pressure of tumors from behind. The condition of the lids as to wounds, scars, loss of motion as in ptosis, or loss of power to close them as in facial paralysis, inversion or e version of their margins, the condi- tion of the cilia, their irregularity, distribution or loss should be observed. The margins, whether normal in color and thickness, or red, ulcerated and thickened; and the presence or absence of tumors, swellings, or styes. The prominence of the eyeball with loss of motion in any direction from orbital tumors, Basedow's disease, etc. The mobility of the eye being decided by having it follow a pencil held in front of the patient and moved in various directions. The next thing to be done is to open the eyelids to gain a view of the front of the eyeball. This is done by placing the thumb upon the skin, above or below the eye, and by DETAILED EXAMINATION. 21 gentle traction separating the lids. This must be carefully- done so as not to give pain, or by making too much pres- sure upon the eyeball cause its rupture, as might easily happen in cases where the cornea is diseased. It will become necessary in some cases to use metallic retractors which are provided for the purpose. Upon opening the eyes the appearance of the cornea is shown, whether normally trans- parent or exhibiting the presence of foreign bodies, maculae, or partial or complete clouding, as in pannus, pustular ulcera- tions and keratitis. If the eyes are inflamed, determine what tissue is affected. If it is the conjunctiva, notice the color, amount and nature of the discharge, whether it be stringy, muco-purulent, or puru- lent. If only one eye is affected, or if no discharge is present, evert the eyelid and examine for some foreign body which may have lodged in the palpebral folds. The lower portion of the conjunctiva is easily brought into view by pulling the lower lid down. An examination of the upper portion requires the aversion of the upper lid, which is readily accomplished, after a little practice, by seizing the eyelid between the finger and thumb, and drawing it away from the globe, at the same time directing the patient to look downwards, while the third finger or a small probe-like object catches the upper border of the tarsus and pressing it down the lid is everted, and its conjunctival surface and the upper cul-de-sac brought into view. At a glance we take in the appearance of the lower portion of the conjunctiva, noticing whether it present the normal salmon tint and is smooth, or injected, thickened or granulated. If the source of irritation is not thus revealed, we may find it in the closure or eversion of the lachrymal puncta, which, instead of being directed towards and touching the conjunctiva of the ball, are turned upward or outward. The eye may present a suffused appearance, or the tear fluid passes over the lid to the cheek, when pressure upon the sac-like swelling on the side of the nose near the inner angle of the eye will cause a flow of pus through the canaliculi into the eye, thus indicating an inflammation and stricture of the lachrymal sac. 22 DISEASES AND INJURIES OF THE EYE. The transparency of the cornea, the presence or absence of inflammatory or cicatricial spots, and irregularities of surface must be determined before making an examination of the- deeper portions, or the appearances due to the shadows from irregularities or spots upon the surface may cause confusion when projected upon the lens or retina. Touching the cornea with a bit of paper will reveal at once, whether it possesses a proper degree of sensibility. The color, mobility and shape of the iris are then to be noticed. If in a comparison of the color of the two irides we find that one differs in color from the other and the eye is inflamed, iritis should be suspected. In a healthy condition, there is frequently a difference in the color of the two eyes, as one may be gray and the other blue ; or one brown and the othei 4 yellowish brown; but if one is blue and the other greenish, we should look for inflammation, either present or past, of its structure. To determine whether the pupil dilates or contracts freely under the stimulus of light, the patient is placed before a moderately strong light. Covering the eye not under examination with one hand, the other is passed back and forth slightly in front of the eye to be tested, while at the same time the action of the pupil is noted from the side. If the iris is in a normal condition, it will dilate as the hand shades the cornea and contract the moment the light is allowed to strike the eye. Any loss of this power of action on the part of the iris is indicative either of mechanical obstruction, as when united to the lens capsule by present or former inflam- mations, or of retinal, optic nerve, spinal, or cerebral diseases. The pupils may present an enlarged and inactive condition, as in some cases of loss of vision in glaucoma and paralysis of the third nerve. The character of the pain described by the patient will assist more frequently in deciding our prescription than in diagnosing the disease. In affections of the conjunctiva the sensation is usually described as smarting, burning, sandy, or as if the eye was full of sticks, etc., and indicates usually some superficial affection, which may, however be DETAILED EXAMINATION. 23 a reflex one. Inflammation of the cornea, and particularly of the iris, presents severe pains, and an aching which is only rarely assigned to the eyeball, more frequently affecting the distribution of the fifth nerve about the eye. Pain deep in the eye, or behind the orbit is often an accompani- ment of asthenopic troubles; while aching over the eye in the forehead and eyebrow, often extending back into the head, is an indication of fatigue of the accommodation, or some error of refraction, as astigmatism. From the vascularity of the eyes, valuable information may be derived from a close inspection of the distribution of blood- vessels upon the surface of the eyeball. The vessels of the conjunctiva, which are invisible in health, present a bright red injection which extends up to the cornea, and is found to move with the conjunctiva as it is moved over the globe under the pressure of the finger upon the edge of the eyelid, indicating the presence of conjunctivitis.' A second system of blood- vessels which become apparent in diseased conditions is that of the anterior ciliary arterial branches, consisting of small, straight, parallel vessels radiating from the cornea, which are not affected by any motion of the conjunctiva. This injection constitutes a pinkish ciliary zone which indicates some irrita- tion, as a foreign body upon the cornea, or ulceration or inflammation of both the cornea and iris. It becomes necessary to ascertain the tension of the eyeball in cases where the cornea, iris, ciliary body, or choroid are inflamed, or after injuries. Eyeball tension is readily obtained by directing the patient to gently close the eyelids and turn the eyes down, when the tip of the index finger of each hand is placed upon the eyeball over the closed lids and as far back on the sclera as possible ; light alternate pressure is then made by the tips of the fingers, when the eyeball in its normal condition is felt to dimple under one finger, while at the same time a direct impulse from the fluids of the eye is given to the other finger. The normal tension of the eyeball, which is indicated by the symbol Tn., differs in different individuals, and at different times in the same individual. The tension 24 DISEASES AND INJURIES OF THE EYE. may be increased or lessened according to the amount of secretion which is retained in it. The degrees of tension are given as T, T+l, T+2, T+3; indicating first, normal tension, second, slight increase; third, decided increase; fourth, stony- hardness. The eye at times shows a decreased tension as in eyeball atrophy and detachment of the retina. Here the various degrees of lessened tension will be indicated by the prefix of -before the degree of T; as T 1, T-2, T-3. In cases of doubt the interrogation point is used, as T+ ?, T ?. TEST FOR COLOR. It becomes necessary in our diagnoses to test the color per- ception, which is readily accomplished after the method of Holmgren, known as the confusion test. This consists of matching small bundles of colored worsteds of red, orange, yellow, green, yellow-green, blue, blue-green, violet, purple, pink, brown and gray. The patient is given a sample of the worsted and directed to select from the balance other bundles of the same shade as the given sample, which he does very readily if not color-blind. If, however, he is given a green sample and selects red or gray tints and places them with the other, the color perception for green is absent. If given a scarlet skein and he takes brown or dark gray, or dark-green shades, he is color-blind for red. These are the two most common forms of color-blindness. Where these tests are made for the examination of railroad and steamboat employes, instead of green or scarlet skeins, those of light purple or rose color should be used, as these colors are composed of red and blue. The red-blind will select blue shades to match with them, because he perceives only the blue in the purple, while if he is green-blind, he brings only the green sample to match the purple. FIELD OF VISION. To assist in diagnosing certain eye affections, such as glau- coma, hemiopia, and atrophy of the optic nerve, it becomes FIELD OF VISION. 25 necessary to examine the power of the eccentric portions of the retina to perceive objects. In the normal eye when the gaze is fixed upon an object, the eye being at rest, not only this object but many others lying within a circle ^extending some distance about it, are more or less distinctly seen. A distinct sharp image of the object looked at is formed upon the macula lutea, and is termed central or direct vision. The images of surrounding objects, which are perceived at the same time, are focused upon the portions of the retina beyond the macula lutea. The greater the distance from this point to the place where they are focused, the less distinct they become. This is termed peripheral or eccentric vision. The extent of this circle is termed the visual field, and it is fre- quently important to determine whether the normal limits are retained. The shape of this space is oval rather than circular, with the small end upwards, and the fixation point lies nearer to the nasal side, as the bridge of the nose interferes with the extent of vision in that direction, as does also the overhanging eyebrow in the upward direction. Various means have been devised for measuring the extent of the visual field. Ingen- ious instruments called perimeters have been invented for the purpose, but in ordinary practice, a blackboard two or three feet square having a white dot in the center will be sufficient. For testing the visiial field, the patient should be seated before the blackboard so that the eye to be tested is about twelve inches from the surface of the board and in a line with the centre, then, having closed or covered the other eye, the eye to be examined is directed upon a cross-mark in the centre of the board. Then the surgeon slowly projects a piece of white chalk from the temporal side of the patient until he perceives it, when a mark is made upon the board at that point. In this way the chalk is carried in a circle around the centre of fixation, marking the most extreme points which the patient is able to see, while his vision is concentrated upon the dot. Lines connecting the various points thus made upon the blackboard form the boundary which encloses the field of vision. It may be roughly taken by having the patient close one eye and with the other look at a button upon the coat of 26 DISEASES AND INJURIES OF THE EYE. the surgeon, who stands in front of him; the fingers or an object held in them, then describes the circle, which is mentally registered by the examiner as forming the limits of the field of vision o^ the patient. The field of vision for colors differs somewhat from that for objects, and diminishes in size for the various fundamental White Blue Red Green FIG 11. colors, as in the chart Fig. 11, from blue which presents the largest field, through yellow, orange and red to green, which has the smallest visual field. The color field may be mapped in the same manner as above, colored chalks being used instead of the white. TESTING THE ACUTENESS OF VISION. To determine and record the condition of the vision, which may be impaired from a variety of causes, it was necessary that some standard of comparison should be agreed upon. For this purpose test types have been prepared by Snellen upon a definite scale, and the standard thus taken is the power TESTING THE ACUTENESS OF VISION. 27 of the normal eye to distinguish the form of letters which in length are equal to the measure of an angle of five minutes, and the limbs of the letters are one-fifth the height of the letter in thickness, thus subtending an angle of one minute at a distance corresponding to the number of the letter. These types are arranged so that each size is numbered according to the distance in feet, or metres, at which it subtends an angle of five minutes. Thus, No. 1 is seen at one foot; No. XX at twenty feet. The acuteness of vision, denoted by the letter V, is expressed by a fraction of which the denominator is the number of the type and the numerator the number of feet at which it is seen. For example, the one more frequently used is No. XX of Snellen, which should be seen, in a well lighted room, at twenty feet. If these letters are read at that dis- tance, then the sharpness or acuteness of vision is expressed as ~V=f-$-. If, however, those which should be read at fifty feet, are alone seen, then V =---. The acuteness of vision thus measured is not always accurate, as many persons have the power to distinguish letters, say of No. XX, at still greater dis- tances, but this test is sufficiently approximate for all practical purposes. If the vision is so defective that the larger letters can no longer be distinguished at any distance, then the fingers should be held between the patient and the light, and the dis- tance at which he is able to count them, noted. If the visual acuteness is still lower than this, he may yet be able to deter- mine the kind and color of reflected light, and is then said to have only qualitative perception of light. If, however, he i& only able to distinguish light from darkness, or notice the dif- ference between light and shadow, as in cutting off the raya from a window or gas jet by passing the hand before the eyes, he retains only quantitative perception of light, and the vision only falls short of absolute blindness. RANGE OF ACCOMMODATION. The examination of the range of accommodation consists in measuring the distance between the nearest and farthest points 28 DISEASES AND INJURIES OF THE EYE. at which test types are seen, which should be read at one foot. Thus No. 1^ of Snellen may be read up to within five inches of the eye, and also at a distance of eighteen inches. The difference between five inches and eighteen inches gives the range of accommodation. Relative accommodation is the term applied to the involuntary association of the accommodation with the convergence of the optic axis. In converging the eyes upon an object at a foot distant, we can accommodate for that distance or lessen or increase the accommodation without the exertion of the internal recti muscles, or without changing their position ; the part which can be increased under these circumstances is termed the positive accommodation, and that which can be lessened without changing the convergence of the eyes, is termed the negative accommodation. FOCAL ILLUMINATION. For a clinical examination of affections of the anterior parts of the eye, as opacity of the cornea, changes in the iris, deposits on the lens in the pupil, cataract, pus or tumors which have extended forward into the vitreous, the oblique or focal illumination is applicable. This consists in converging the rays of light from a lamp or gas jet, in a partially dark- ened room, by means of a convex lens of two or two and a half inches focus. The lens, held between the thumb and finger, is used as a burning glass and brought close to the eye, so that the focused rays are brought to bear upon the part to "be examined in an oblique direction. Thus the cornea, iris, lens and anterior portion of the vitreous may be successively examined by varying the position of the patient's eye, so that the focus of the rays will fall upon the part to be inspected. If desired, the pupil may be dilated with atropine to give a more extended view. The presence of minute foreign bodies projecting from the cornea, opacities in its substance and their depth, hemorrhage, pus or tumors immediately behind the lens, may thus be determined. A second lens may be held in EXAMINATION WITH THE OPHTHALMOSCOPE. 29 front of the eye thus examined, which will give a magnified image of the part under inspection. For an examination of the deeper parts of the eye, as the choroid, retina and optic nerve, the ophthalmoscope must be used. This instrument, which was invented by Helmholtz in 1851 and since improved by Coccius, Reute, Liebreich, Kekoss, Knapp, Loring and others, has revolutionized the science of ophthalmology and made it exact. Owing to the depth of the various tissues in the eye and the smallness of the pupil through which they are observed, it is impossible in their normal condition to examine them with the un- -A aided eye. A tumor within the eye some- times pushes FIG. 12. . . ,, forward the parts from the bottom, the pupil no longer appears black, and certain portions of the interior are thus made visible. The black appearance of the pupil, which was once supposed to be due to the complete absorption of the light rays by the dark pigment of tho interior of the eye, is now known to depend upon the optical law of conjugate foci. The rays of light entering the eye pass through the cornea, aqueous, lens and vitreous, which together, in their refraction of light, may be considered as a single lens. When the eye looks at a gas jet placed at a short distance away, the rays, projecting into the interior, will form upon the retina an image of the jet. These rays are, however, reflected back from the retina, and in their passage are refracted by the eye until they meet again at the gas jet, where they form an image in the flame. These rays of light being limited by the size of the pupil, it is impossible for the 30 DISEASES AND INJURIES OF THE EYE. eye of the observer to catch a sufficient number of them to enable him to sae the interior of the eye, and if his eye is placed in a direct line with the light coming from the eye under examination, the head of the observer at once cuts off the rays from the source of illumination. *If, now, a piece of plain glass, or a small mirror be interposed between the observer's eye and the eye to be inspected, as shown in Fig. 12, and the light reflected into the eye by the glass or mirror, the interior of the fundus becomes at once illuminated and visible. Bays of light passing through the pupil and refrac- tive media are, in the normal eye, brought to a focus upon the '$$ M/Mll '"'Illt/J FIG. 13. > Tetina. A part of these rays are absorbed by the pigment of the retina, while the major portion follow the same course which they took in entering, hence the pupil appears black, because none of these light rays reach the eye of the observer. If, however, the examiner places before his eye a piece of glass, or thin plates of glass (CD} as in Helrn- holtz's ophthalmoscope (Fig. 13), at such an angle that the light coming from a luminous body is reflected into the eye under examination, the light rays in their return reach the glass reflector, and a portion of them pass through to enter the eye of the surgeon at A, and the pupil no longer appears black, but brilliantly red; this KINDS OF OPHTHALMOSCOPE. 31 is the essential principle upon which the ophthalmoscope depends. KINDS OF OPHTHALMOSCOPE. The ophthalmoscope consists essentially of a mirror set in a handle, a convex object lens, and a small ocular lens held in a groove behind the mirror, as in Liebreich's (Fig. 14), or con- tained in disks as devised by Rekoss which rotate upon each other to furnish a large number of lenses of different degree, as in those of Loring and Knapp, for the measurement of errors of refraction. The ordinary requirements of the ophthalmoscope, largeness of the field of view with good illumination, are well met in the small ophthalmoscope of Liebreich (Fig. 14), which consists of a concave mirror of about seven inches focal length with a central opening, attached to a short handle. The back of the mirror is pro- vided with a clip for no. H. , , , . , , holding the necessary correcting lenses. Unfortunately they are usually so poorly made as to be almost useless. To keep pace with the advance- ment of ophthalmic science, more compendious instruments called Refraction Ophthalmoscopes have been devised by Wecker, Loring, Knapp and many others ; the principle mod- ifications consist in the substitution of detachable or revolving disks containing numerous correcting glasses, for the former clip, and changes in the size and shape of the mirror and its perforation. In the Loring instrument (Fig. 15) the mirror is concave and made very thin, with a focal length of seven inches and a central perforation 6 mm. in diameter. The handle is made long so that in holding it the observer's hand does not come in contact with the patient's face in the direct examination. The correcting glasses are held in disks which fit in a cell at the back of the instrument and are retained by means of springs, so that they may be 32 DISEASES AND INJURIES OF THE EYE. rotated in such a manner that the center of the glass comes opposite the center of the hole in the mirror. Less elaborate and equally good instruments have been devised by Loring for ordinary ophthalmoscopic work. These consist of a single revolving disk with perforations for twelve or sixteen convex, and concave lenses, one space being left open to use when no correcting glass is necessary, and furnish a very satisfactory instrument for students and gen- eral practitioners. Loring has added many other modifications to his instruments, as in covering the disks, and the substitution of a tilting mirror of a parallelogram shape instead of circular. Knapp's double disk ophthalmoscope con- sists of the ordinary concave re- flecting mirror as in Liebreich's, Loring' s and others, but with a perforation 3.75 mm. in diameter. This is screwed on a thin plate of metal. On the other side of this metal plate are two disks, of which the upper contains the con- vex lenses and the lower a similar series of concave lenses. Each disk rotates on a central pivot and presses upon a delicate spring with a point-like elevation at the end, which fits into corresponding depressions in the disk, which arrest the disk when the lens which we want is opposite the centre of the aperture of the mirror. The two disks are covered by a metal cover which prevents the soiling of the lenses. The disks overlap at their margins in such a way that each convex glass can be covered by a concave glass. Thus combinations are formed and an extensive series of lenses obtained. The disks are rotated in position by the finger tip applied to the top and side of the instrument. Apertures in the back enable us to read the FIG. 15. KINDS OF OPHTHALMOSCOPE. 83 numbers of the lenses which are behind the opening in the mirror. A short ivory handle screws into a socket in the mirror plate. The single disk instrument of Knapp (Fig. 16) is very- similar to Loring's smaller instrument. The disk contains an FIG. 16. empty hole and twenty -three or more lenses which are covered by metal, and is easily rotated by the finger without losing the ophthalmoscopic image for the time. 34 DISEASES AND INJURIES OF THE >EYE. THE USE OF THE OPHTHALMOSCOPE. DIKECT METHOD. A well -darkened room should be pro- vided, with a good light from an argand lamp, or gas jet, which should ba above or at one side and a little behind the patient, so that his face is in the shadow. The light should not be too intense, as the strong reflection causes too great contraction of the pupil and fatigues the patient. To acquire the skill necessary to see with the ophthalmoscope, frequent examinations should be made upon healthy eyes, as the instru- ment can only be used with satisfaction after much practice. The patient should be feeated in front or to the side of the surgeon, the light being to one side of the patient and on a level with his eye, so that the eyes of both are on the same plane. If the left eye is under observation, the surgeon holds between thumb and fingers the handle of the ophthalmoscope, with the mirror in front of his left eye, and resting the upper edge upon the under side of the eyebrow. The light is reflected by the mirror into the eye. Now if the eye of the patient and also the eye of the observer are possessed of normal refraction and the accommodation relaxes, the pupil appears illuminated at once, and the red reflection from the fundus is obtained. The condition of the lens and trans- parency of the vitreous are now examined. The beginner may be satisfied if this much is obtained during the first attempts with the use of the instrument If, now, the patient's eye is directed upwards slightly, the color of the reflection is changed to yellow by the light falling upon the optic disc, which is much lighter in color than the other portions of the fundus. Having now approached still closer to the eye until the faces almost touch, the arteries and veins upon the disc become plain and the details of the fuudus are carefully studied out. The image thus seen in the direct method, is not a real image, but a virtual erect image which appears as if situated some distance behind the patient's retina. If, at any time during the examination, the observer exerts his accommo- dation, or places a glass behind the mirror the image THE USE OF THE OPHTHALMOSCOPE. 35 disappears. The direct image on the retina is seen by this method only when the eye of the patient and that of the observer are of normal refraction, when the eye of the patient is hypermetropic and the observer's myopic to the same degree, or when the patient has a myopia which is counter- balanced by a similar degree of hypermetropia in the surgeon. The use of convex glasses behind the mirror produces an artificial myopia in the eye of the observer, while concave lenses similarly applied produce artificial hypermetropia. The use of the ophthalmoscope in determining the degree of the errors of refraction will be discussed in the chapter devoted to the errors of refraction. With the direct method the beginner may have much diffi- culty in relaxing his accommodation, owing to the close prox- imity of the eyes. This may be overcome by the use of a convex glass behind the mirror until he has acquired the knack of relaxing his accommodation. With the examination by this method a larger image is obtained than with the other and the exact position of the lesions of the fundus is more accurately determined. The extent of surface of the fundus seen at any one time is less than with the indirect method and depends upon the distance between the two eyes. At 15 mm. it equals the size of the pupil. The nearer the eyes approach the larger the field ; the farther removed, the smaller the field. If the eye examined is not normal but hypermetropic, then a convex glass equal to the degree of hyperopia must be used behind the mirror before the fundus becomes distinct. If a normal eye examines a myopic eye, then a concave lens of the degree of nearsightedness must be used. In each of these cases the image is less magnified than in the normal eye, but is larger in the myopic than in the hypermetropic eye. INDIRECT METHOD. The position of the patient and sur- geon are the same as in the foregoing method, but their heads are separated to a distance of eighteen to twenty-four inches. The ophthalmoscope, with a convex lens of sixteen or twenty- four inches focus in position behind the hole in the mirror, is slightly turned toward the light so that the reflection is 36 DISEASES AND INJURIES OF THE EYE. thrown into the eye, and the red reflexion of the pupil made apparent. With the left hand, a convex lens (L Fig. 17) of two and a half or three inches focus is held between the thumb and fore-finger parallel to the front of the eye, the third finger resting upon the median line of the forehead of the patient and giving support to the hand, while the little finger can be employed to raise the lid if necessary. The lens is thus held about two inches in front of the eye, so that the rays of light reflect- ed on the mirror of the ophthalmo- scope are fo- cused by the FIG - 17 - convex lens in the pupil. The patient is now directed to look in a direction past the surgeon's ear, which brings the optic disc in a line with the pupil, and on moving the head nearer or removing it farther from the eye under examination, a whitish object appears in the illuminated pupil. Slight variations in the position of the head, mirror or lens, which must be acquired by practice, enable the surgeon to obtain a clear and well defined image of the entrance of the optic nerve into the eye, and, following the course of the arteries and veins in their ramification through the fundus from this point, the whole of the interior can be studied by having the patient move the eye in various directions. The image now seen is a magnified real and inverted image (a Fig. 17), which is really formed in the air between the ophthalmo- scope and the lens held before the eye of the patient. The size of the image depends upon the object glass used, and upon the refraction of the eye. If a three-inch lens is used and the eye normal the increase is five and a half diameters. If the eye is hyperopic, it will be larger, if myopic, smaller than with the normal eye. The image thus seen can be further enlarged by using a weaker convex object glass, say OPHTHALMOSCOPIC APPEARANCE OF NORMAL FUNDUS. 37 i four-inch, which must be held farther from the eye of the patient, and also still further increased by having a stronger convex lens behind the mirror, say one-eighth. OPEIHALMOSCOPIC APPEARANCE OF THE NORMAL FUNDUS. The cornea, aqueous, lens and vitreous in the healthy eye, Toeing perfectly transparent, are invisible and present no reflex under examination with the ophthalmoscope. The fundus of the healthy eye when brought into view through the pupil, presents a reddish-orange reflection in blonde people where the retinal pigment is not sufficiently deep to prevent the reflection of the light from the choroidal vessels. In brunettes, the pigment being darker, these vessels are obscured, and the light reflected from the pigment through the retina gives it a grayish FIG> 18 - color. The fundus of the eye, when Tiewed by the ophthalmoscope, presents for examination, first, the optic disc (Fig. 18), or entrance of the optic nerve. This, when the patient is looking in the proper direc- tion, changes the red reflection of the interior to a whitish hue which fills the pupil and presents a well-defined outline. This light color is due to the absence of the choroid and retina at this point. Around this disc is a still whiter collar, due to the scleral fibres surrounding the entrance of the optic nerve, and termed the scleral ring. In other cases this circle presents a dark or black appearance due to the retinal pigment, and is termed the choroidal ring. At times, this pigment forms only a segment or crescent. These pigmen- tary deviations are not to be mistaken for pathological changes. The surface of the disc frequently presents a more or less opaque white portion, which is due to a depression of the central portion of the nerve, and is termed the physiolog- 00 DISEASES AND INJURIES OF THE EYE. ical e&cavation. It varies in size, but rarely occupies the whole extent of the disc, and should not be confounded with the cupping which occurs from pressure, as in glaucoma. Upon the disc, vessels are seen emerging at or near its centre. These are the central artery and vein of the retina. The artery, which is smaller and of a light red color, and presents a double contour or light streak along the centre, usually divides into two branches, one running upward, while the other takes a downward course, again dividing and rami- fying through the retina. The veins, which are larger and of a darker color and more tortuous, are usually three in number : two coming from below and one from above, and uniting in the centre to form the central vein. Further inspection of the disc shows smaller vessels upon its outer portions. These are nutrient capillaries, and give to it the reddish appearance. The reiina being perfectly transparent, nothing is seen except the ramifications of the arteries and veins which sweep off from the optic disc. Possibly, slight, fine lines near the disc and along the main branches of the vessels may be apparent and are due to slight opacities in the optic nerve fibres. In brunettes or negroes the retina presents a bluish film which is more apparent near the optic nerve, where the retina is thicker. If the retina 'appears hazy, the difficulty may be due to want of transparency in the cornea, lens or vitreous. This, of course, should be determined before further examination of the retina. The choroid, from its large vascular supply, gives to the fundus its red tint, but nothing is seen of it with the ophthalmoscope, except that where the retinal pig- ment is abnormal, the outlines of the vense vorticosse and of the choroidal vessels become apparent. If the pigment layer is thin, as in blondes, or absent, as in Albinos, then the choroidal vessels become visible and present a striking- picture. These vessels are easily distinguishable from those of the retina, as they present a lighter appearance, are mucli larger, not traceable to the optic disc, and present no light streak. The macula lutea and the fovea ceniralis, its minute KERATOSCOPY. 39 depression, are examined with difficulty unless the iris and the accommodation are paralyzed by atropine, as it lies in the direct line when the patient looks at the hole in the mirror, and the exercise of the accommodation and the consequent contraction of the pupil and the puzzling reflec- tions, prevent its being observed in more than one-third of the cases examined. It appears as a minute red spot, some- times surrounded by a yellowish or whitish ring; the latter is more frequently observed in dark-complexioned children. The absence of any change in the retina more frequently determines its normal condition than the appearance of the part itself. The sclera is not seen in an examination of the fundus, unless the choroid has been destroyed or atrophied, when it appears of a glistening white at the point of lesion. KEEATOSCOPY. Keratoscopy is an additional method of examination which has been recently introduced for determining the refraction of the eye, and requires for its application a concave oph- thalmoscopic mirror. The patient may be seated about forty inches distant, with the light to one side, so that it falls upon the mirror and is reflected into the pupil of the eye to be examined in a very oblique direction. Looking through the perforation of the mirror a red reflection is obtained, and approaching or removing farther, a clearly defined image is formed; this image is surrounded by a dark shadow and moves with any rotation of the mirror. The observer's eye must be normal, or corrected by a suitable glass behind the mirror, and then upon rotation of the mirror the image and shadow will be found to move in the opposite direction if the eye be hypernietropic, emmetropic or slightly myopic. If the eye is more myopic the image and shadow move in the same direction as the rotation of the mirror. To deter- mine the amount of the error, lenses are rotated behind the mirror, until, in the case of hyperopia, the image moves 40 DISEASES AND INJURIES OF THE EYE. with the rotation of the mirror. The glasses prescribed by this method are always stronger than the practical glass, and it is not likely to supersede the more exact method of Ophthalmoscopy. CHAPTEE III. GENEEAL CONSIDEEATIONS OF TEEATMENT. L T SE OF ANESTHETICS. In regard to the use of anaesthetics, it may be said that while many operations upon the eye are excessively painful, there are also many which are not so, but seem very alarming to the patient, and the nervous anxiety accompanying the announcement that an operation of any kind is necessary is sufficient to deprive them of self-control. Even if an imme- diate consent is obtained, the patient is oftentimes unable to withstand even a very minor operation upon the eyeball, as the motor muscles are but slightly under control of the will under these circumstances, and unless the utmost care and patience are exercised by the surgeon, the agitation of both the eye and the patient are apt to so interfere with the opera- tion as to render his skill less likely to achieve a favorable result. For the many delicata operations upon the eye it is much better to render it perfectly passive by the use of anaesthetics and thus prevent any spasmodic movement of the eye, or sudden compression of the ball by the sudden closure of the lids, during or at the close of the operation. In regard to the choice of anaesthetics the author believes that ether, while consuming more time in its administration, is otherwise as suitable for all operations upon the eye as chloroform and presents much less risk. 41 42 DISEASES AND INJURIES OF THE EYE. BANDAGING. In diseases or injuries of the eye absolute rest of the part may be necessary for the purposes of healing, for the friction of the lids as they move over the cornea or conjunctiva may become not only painful but injurious. For the purpose of preventing the movements of the eye and thus securing perfect rest during the process of repair a bandage is used. This may be of two kinds, compress or pressure and retaining bandage. A compress bandage is applied after first covering the eyelids with a small square of thin linen or muslin, and picked lint (charpie), absorbent, or borated cotton, placed bit by bit upon this in such a manner as to fill up all tho irregu- larities of the surface to a level with the brow, the lighter portion of the packing coming upon the lids over the most prominent portion of the eyeball. The bandage is made of a strip of soft flannel or merino 1^ inches wide and 1| yards long and rolled. When both eyes are to be bandaged the length must be increased to 3i yards. In its application the free end of the roller is applied to the temple on the side of the affected eye, and the roller is then carried around the head to the starting point. It is now carried down obliquely across the occiput and under the ear and then brought up over the covered eye with slight tension of the edge of the roller nearest the nose, pinned to the layer on the forehead, reversed and carried above the ear, thence down across the occiput and up over the eye as before, tension being made this time upon the outer edge of the bandage and pinned as before, the roller turned and the end secured by pinning above the ear. If desired, a third layer may be applied to the eye. When both eyes are to be covered the double pressure ban- dage is applied in the same way except that the bandage is laid flatter and after the first layer has been brought to the median line of the forehead the pin is put in horizontally, the roller reversed, and carried down over the second eye so that the inner layer of the bandage of the first eye becomes the outer layer of the second, and is passed down under the ear BANDAGING. and below the occiput and brought up under the ear and over the first eye, reversed to cover the second eye and the end secured as before. After removal of the eyeball or the contents of the orbit, the packing should be more solid and the bandage applied with greater pressure. A figure eight bandage may be used for the same purpose ; the end of the roller is applied at the median line of the nape of the neck and passed forward over the face on either side as desired, and along the line of the nose and across the root of the nose to the other side, thence over the occipital prominence, then, around and over the second eye, down the face to the back of the neck opposite the beginning. Continue in this way until two lines of bandage are laid on each eye and then the balance carried across the head and pinned. Difficulty is experienced in keeping any form of the bandage in position for any length of time, and extra pinning or stitching together will be neces- sary. The wearing of a light knit night-cap over the bandage will often serve an excellent purpose in retaining it in proper position. As the condition of the eye improves, or when it is neces- sary to make frequent applications to it a retaining bandage is substituted for the pressure bandage. A convenient form is. made of one or two thicknesses of muslin 2 inches wide by 7 inches long, either square or tapering at the ends to which tapes are attached. Two tapes are fastened at one end and one at the other. The bandage is to be applied diagonally across the eye which has been covered with a bit of soft linen, upon which is placed a small mass of absorbent cotton; one tape from each end is carried to the back of the head, crossed, brought forward and tied in front, while the remaining tape is carried below the ear on the side of the well eye, around to the back, thence over the top of the head, and pinned where it crosses the others. For retaining wet dressings on the eye a muslin bandage 1^ inches wide and 1 yard long is required. It is used in the following manner: Begin at the top of the ear and pass up a little in front of the vertex and then around the head 44: DISEASES AND INJURIES OF THE EYE. below the occiput, and with the finger beneath the bandage above the ear, draw firmly and pin ; the loose end of the ban- dage is then carried over the compress and pinned to the head band. For both eyes a right-angled head bandage is used. EYE SHADES. For simple protection of the eyes from direct light, colored protective glasses made of plain tinted glass, preferably the smoke-tint, may be used, the tint to be determined by the nature of the case. For more full protection eye shades made of card-board and covered with black silk are very comforting to the patient in many cases and allow of his taking the exer- cise which may be needful in hastening recovery. COLD AND HOT APPLICATIONS. There are many conditions of the eye where the application of cold or heat alleviates pain, retards reaction or promotes resolution. These may be wet or dry according to the neces- sities of the case. The temperature of the applications may usually be left to the choice of the patient. The time of the application is to be regulated by its effect and the severity of the inflammatory process. As a rule it is better to apply them only for a few minutes, or half an hour, rarely an hour, and then after an interval of half an hour, an hour, or longer re-apply them. During the interval the eye is to be cleansed and a bandage applied if necessary. For cold applications wet compresses can be used, formed of several thicknesses of old linen soaked in cold water, or laid upon a large piece of ice in a basin near the bedside, and changed as often as required. If dry cold is to be used, a small rubber ice-bag filled with chopped ice, and placed within the folds of a clean towel so that at least one thickness of the towel comes between the ice-bag and the eye, is laid upon the eye and retained in position by pinning the ends of the towel behind the head, or to the pillow. This form of CLEANSING THE EYE. 45 cold application can be used in cases of conjunctival inflam- mation for several hours at a time with benefit and comfort. Hot applications may be used dry, by means of hot flannels, bags of hot bran or hot salt, as in the ciliary neuralgia of iritis, or flannels wrung out of hot water, compresses wet in a. warm decoction of chamomile flowers, calendula, or hops, and poultices of pulverized slippery-elm bark, or flaxseed, as in suppurative cases of the lids, orbit, or cornea. Moist heat must not be applied continuously for any length of time as oedema and relaxation of the tissues result, and ulceration or slow recovery follows. Eye douches are used in some chronic cases, a stream of water being directed against the closed eye- lid from a fountain syringe, the temperature of the water being that which is most grateful to the eye. CLEANSING THE EYE. For removing discharges from the ey& small bits of old muslin, linen, camel's- hair brushes or absorbent cotton or the sub-palpebral syringe of Dr. Liebold (Fig. 19) may be used. With whatever method employed, the end is better at- tained by the use of some disinfectant lotion. Chlorine water, which may be diluted one-half or one-third, or used in full strength, as the irritation after its- use is very slight, forms one of the best disinfecting lotions. Boracic acid, grs. viii ad fi, is more frequently at hand and gives good satisfaction. MYDRIATICS AND MYOTICS. Certain substances which possess the power of dilating or contracting the pupil when applied directly to the eye have received the name of mydriatics and myotics. Among the mydriatics are sulphate of atropia, hydrobrornate of homatro- G.TJfMANN &CO FIG. 19. 46 DISEASES AND INJURIES OF THE EYE. pine, belladonna, hyoscyamine, daturine, gelsemium, and the sulphate of duboisia. Until a recent period atropia sulphate has been considered the most useful and important of the mydriatics, but homatropine and duboisia are now filling needed places in the armamentarium of the oculist. They are all poisonous and exert their toxic effects on passing through the tear passages to the throat and there becoming absorbed. For general purposes where the dilation of the pupil is desired, the solution of sulphate of atropia, grs. iv. ad f^i of waiter, will furnish the best mydriatic. In its application a drop is to be placed in the lower conjunctival fold with a medicine-dropper (Fig. 20), and in ordinary cases after twenty minutes or half an hour the pupil will be found to be fully dilated. The paralysis of the ciliary muscle follows in from one and a half to two hours, lasts a day, but does not entirely disappear for one or two^weeks. It also acts as an anodyne in relieving the reflex irritation from the nerves of sensation of the cornea and iris. Where care is not used in its frequent application, the symptoms of atropine poisoning may occur. These are usually, first dryness of the throat, then flushing of the face, headache, palpitation of the heart, acute mania, deli- rium, retention of urine, urging to urinate, nausea and prostration. On the occasion of any of these symptoms the use of the atropine should be stopped FIG. 20. and draughts of black coffee administered until vomit- Ing takes place, or morphia or brandy may be given if the prostration is great. If the atropine is dropped into the eye near the outer canthus and the head held to that side for a few moments or pressure made over the lachrymal sac the poisonous effects are not likely to prove troublesome. In young children a solution of 1 gr. to the f 3 should be used. In rare cases atropine produces irritation or inflammation of the conjunctiva, In these cases sulphate of duboisia, grs. iv ad f si, will prove useful. It has the same effect upon the eye as the atropine, the full effect being obtained in an hour, but INSTRUMENTS. 47 lasts only about six hours and its influence disappears in about seven days. Its toxic effects appear more rapidly and are more alarming, and are usually vertigo, unconsciousness, or extreme prostration. Homair opine hydrobr ornate, grs. xvi ad fi, one to three drops, in the eye dilates the pupil and paralyzes accommodation in an hour, but the effect passes off in 24 or 36 hours. The other mydriatics mentioned above are rarely if ever used in ophthalmic practice now. Of the myotics we have the liydrobromate of pilocarpine and the sulphate of eserine. The former is mild in its action and has been recommended as a local tonic for the ciliary muscle. In a solution of gr. iv ad ffi, it produces contraction of the pupils and spasm of the ciliary muscle, the effect passing off in 36 to 48 hours. The sulphate of eserine is a more powerful myotic, a solution of grs. iv ad f 51 causing the utmost contraction of the pupil, and spasm of the accommodation with pain, in half an hour to an hour; its effects are transient and disappear in a few hours. It is used to draw the iris away from a peripheral ulceration or wound of the cornea, to counteract the paralysis of the iris or ciliary muscle and in some cases of glaucoma to draw the periphery of the iris away from the angle of the iris, thus lessening the pressure upon the canal of Schlemm. INSTRUMENTS. In all operative procedures upon tlie eyeball, the lids must be held apart by the fingers of a competent assistant, or Desmarres's lid elevators (Fig. 21) employed, or a speculum, designed for the purpose, used. A variety of the latter instruments have 48 DISEASES AND INJURIES OF THE EYE. been devised and are in use by different operators. The requisites of a proper speculum are that the lids should be as widely separated by it as the palpebral fissure will allow, it should not cause any pressure upon the eyeball, and should not project from the lids or k temple so as to in- terfere with the manipulations of the surgeon. There 6. T1EMANN S C 0. /V. K FIG. 22. FIG. 23. is no single speculum which is well suited for all purposes. An ordinary wire speculum will answer for many cases. That of Noyes (Fig. 22) is as well adapted as any form of spring speculum for common use, but is often impracticable when the eyes are deep set. That of Liebold (Fig. 23) possesses admirable features, as when properly made the body rests on the temple and conforms itself to the action of the face. It is out of the way of the operator. There is no spring action, the limbs being governed by a slide to which a small thumb-screw is affixed. With the FIG. 24. spring speculums it has happened to all operators, during the removal of the speculum after an operation, that on turning the instrument slightly it has slipped from the fingers and perhaps struck the eyeball. This accident might prove serious after an operation for cataract, iridectomy, etc., and is avoided by the use of LiebolcVs speculum. The speculum is readily introduced by slightly lifting the upper lid and inserting the INSTRUMENTS. 4:9 upper limb of the speculum and then the lower lid is retracted sufficiently to allow the lower portion of the instrument to rest in the lower conjunct! val sac. For steadying the eyeball a, fixation forceps (Fig. 24) is used, and this may be made with or without a spring catch. It should be handled so as to simply turn the eye by slight push- ing and not drag it. The application of the forceps becomes painful and if not carefully manipulated it will tear the con- FIG. 25. junctiva. The Beers knife (Fig. 25) will be found a very useful form of scalpel for operations about the eye, the blade being very thin, well pointed, and yet sufficiently firm for all purposes. The great variety of other instruments are specially designed for particular purposes and will be considered under tho descriptions of the different operations. CHAPTER IV. The proper management of traumatic injuries of the eye is of the utmost importance, as the resulting condition of the eye depends very much upon the treatment to which it is subjected immediately after the injury. The full extent of the injury should be ascertained, and frequently it will be necessary to etherize the patient, particularly if a child, to gain a complete inspection of the eye. "Where practicable, the vision should be tested and noted, as a direct examination of the eye fre- quently has a legal aspect as well as a surgical one. Having determined the parts injured and the extent of the lesion, and decided upon the treatment necessary, give the eye perfect rest and refrain from frequent examination, which may retard the process of repair. INJURIES OF THE OKBIT. The orbit is often the seat of punctured and gunshot wounds which may or may not directly implicate the eyeball. Blows directed upon the margin of the orbit may cause simply a con- gestion of the soft parts with ecchymosis of the lids, or produce a fracture of one of the orbital walls. The presence of effused blood beneath the conjunctiva of the bulb, within a few hours or just following the injury, is an indication of rupture of the blood-vessels of the orbit. A careful ophthalmoscopic examination should be made, as serious changes may result at the same time internally or behind the eye. Oftentimes a INJURIES OF THE LIDS. 51 fracture of the orbit is overlooked in other serious injuries of the head and is followed by loss of sight in one or both eyes without much change in the fundus. Rest, cold applications, and arnica locally and internally, are usually sufficient, the blood being absorbed in a few days. Punctured or gunshot wounds of the orbit demand a thorough search for foreign bodies by means of the little finger or probe and their immedi- ate removal, when found. If the entrance wound is not sufficiently large to permit the removal of the imbedded object, it must be further enlarged. In cases where small shot, as bird shot, are projected into the tissues of the orbit, those near the surface should be removed, but deep incisions and probings in the structures of the orbit are not advisable, as these foreign bodies if left to themselves frequently become encysted, or come to the surface after a time. The direction of punctured and gunshot wounds, demands consideration and affects the prognosis of this class of injuries, for, if the roof is implicated, hemorrhage, inflammation and abscess of the brain may result. If the floor of the orbit has been fractured or punctured, blood from the nose is often symptomatic, and besides the opening of the antrum, injury to the infra-orbital nerve may result. In the treatment of these injuries of the orbit all foreign bodies, fragments of bone, etc., are to be removed, the parts thoroughly cleansed, and cold compresses applied, with rest and the maintainance of a free opening for discharges. If orbital cellulitis supervenes and abscess forms deep in the orbit, an incision to allow free discharge is imperative, and if cerebral complications ensue, it may be necessary to remove the eyeball. INJURIES OF THE LIDS. Wounds of the lids, however extensive, must be thoroughly cleansed with warm water, all portions of clothing, hair, dirt, etc., removed, the edges of the wound well brought together and united with as many fine sutures as may be necessary to insure a full adaptation of the lacerated tissues, when primary 52 DISEASES AND INJURIES OF THE EYE. union will almost always take place. Generally the applica- tion of dry dressings is all that is necessary. If, however, the- wound becomes painful, cold compresses of calendula water and the use of Aconite, Arnica, or Calendula internally are indicated. The ecchymosis of the lids or " black eye " from contusion requires the use of Arnica externally and Hamamelis inter- nally. Incised wounds of the lids may cause ptosis from the division of the levator palpebrse, or if in the supra-orbital region, loss of sight as well. Burns of the lids may cause changes in the position by the resulting cicatrices and require the same treatment necessary for burns of the cuticle else- where. Superficial burns of the eyelids become more impor- tant than similar burns on other portions of the skin. If the lids are severely burned or scalded, lint soaked in a solution of lime water and linseed oil, or a thick paste of bicarbonate of soda should be applied to the parts. The latter I have found relieves pain more rapidly than any other dressing. Occasionally Cantharis will do good in lessening the tendency to suppuration which follows in these cases. Where cicatrices form, plastic skin operations will have to be considered later. Gunpowder grains imbedded in the tissue of the lid require the most painstaking effort at their thorough removal. INJURIES OF THE LACHRYMAL APPARATUS. Foreign bodies sometimes find their way into the lachrymal conduits, as lashes, hairs, bits of straw, etc., and should be looked for in the puncta when the irritation is not found else- where. Where these ducts have been divided by wounds, the repair cannot be expected to restore the integrity of the parts, and future operations may be necessary to open them. INJURIES OF THE CONJUNCTIVA. The injuries sustained by the conjunctiva are numerous, and in extent usually greater than those of the eyeball. They may consist of incised wounds, burns, or foreign bodies upon INJURIES OF THE CONJUNCTIVA. 53 or in its tissue. Foreign bodies impinging upon the surface of the conjunctiva are usually washed off by the profuse secre- tion of tears caused by the irritation, unless the efforts of the patient to remove them by rubbing, imbed them in the tissue. If a small fly, or other minute insect, or foreign body becomes lodged in the eye, it is usually found near the palpebral margin of the upper lid, each movement of the lid causing severe pain as the object scratches upon the cornea. Upon aversion of the upper lid it is removed without difficulty. If it remains for any length of time, or an eye-stone is inserted, conjunctivitis results, but rapidly subsides upon the removal of the foreign body or eye-stone. Gunpowder grains become imbedded in the conjunctiva from explosions, and necessitate the removal of all free grains, and the excision of minute portions of the conjunctiva together with those grains which oecome imbedded in its tissue. This may be done immediately after the injury has been received, or, if the reaction is too excessive from the injury to other parts, their removal may be left until some future time, when the eye has recovered from the immediate effects of the injury. Incised wounds or lacerations of the conjunctiva require little, if any, treatment, beyond the use of cold compresses and enforced quiet of the eye by bandaging, as they heal very readily. Burns of the eye from lime, mortar, molten metals, ammonia, sulphuric and nitric acids, or other caustic substances are very common, affecting the conjunctiva, and requiring the installation of such oily substances as cream, vaseline, sweet oil, etc., which may be at hand. In the case of lime or mor- tar, all particles must be carefully picked from the conjunctival fold by forceps or a spud, and syringing may be necessary to remove more minute bits. Etherize the patient, if necessary to do it perfectly. After all have been removed, instil castor oil or vaseline between the lids and keep the eye at rest. Burns from melted metal are usually less deep than those of lime, as the metal solidifies rapidly and is more easily removed. Eschars are produced from acetic, sulphuric, or nitric acids, or concentrated lye ; and after the parts have been well washed 54 DISEASES AND INJURIES OF THE EYE. with water the reaction must be waited for. The use of alka- line solutions in the case of acids, or acid solutions in the case of the introduction of alkalies into the eye is misleading, as the danger is usually done before the antidote in either case can be applied, and the superficial injuries sustained by their dilution in large quantities of water, are very slight. The danger in burns of the conjunctiva, from whatever cause, is from adhesion of the granulating surface after the eschar has been discharged, and this union of the conjunctiva of the lids and globe cannot be prevented any further than by the con- stant instillation of oil, and perhaps the frequent breaking up of the cicatricial bands by the probe. The adhesions which form from the contracting cicatrix requires future operation. If these burns have not involved the cornea, there is no necessary impairment of vision, unless the adhesions are sufficient to impede the motion of the eyeball so that its move- ment is not associated with its fellow. INJUKIES OF THE COKNEA. Foreign bodies, particles of iron, cinders, seed husks, etc., become imbedded in the cornea, and may present only slight, if any, irritation for several days, after which time inflamma- tion or pain occur. In the removal of these foreign bodies if FIG. 26. FIG. 27. the eye cannot be controlled, an anaesthetic must be used, Under ordinary circumstances, the patient may be seated upon a chair of ordinary height before a good light with his head resting upon the chest of the surgeon, who stands behind. The operator fixes the eyeball with the thumb and fore-finger of the left hand, and making slight pressure upon the margin of the orbit, the eyeball is well controlled. In a majority of INJURIES OF THE CORNEA. 00 cases, with a sharp gouge (Fig. 26) or spud (Fig. 27) in the other hand, the foreign body will be raised and removed without difficulty. If, however, the hand is not steady, the other portions of the cornea are touched and the pain will be severe. If a foreign body extends into the deeper layers of the cornea, or into the anterior chamber it will become necessary to enter a narrow cataract knife through the anterior chamber and by cutting outwards, remove it, or, using the knife tip for a rest, the foreign body may then be seized by a pair of forceps and withdrawn. The after-treatment of such cases is, as a rule, very simple. The instillation of a drop of atropine and the application of a bandage, even in those cases where the cornea has been incised are, oftentimes, all sufficient. In cases of foreign bodies simply impinging upon the cornea, the use of a lotion of aconite tincture and water relieves the pain from exposure of the nerve filaments in the cornea, and hastens repair. If suppuration has commenced about the point of entrance of the foreign body, atropine two or three times a day will generally relieve the pain, while the use of Aconite, Hepar sulphur, Silicia, or Mercury, as the case may indicate, will hasten the reparative process. Scars that may be left will injure vision according to their position and extent, by lessening the transparency of the cornea. Abrasions of the surface from the scratch of the finger-nail of a child or a twig, require usually only a bandage and rest for the eyes during forty-eight hours, until the epithelial layer has again been re-produced. If occurring in nursing women, or where there is a low condition of the system, suppuration of the cornea and destruction of vision may result. Contusions of the cornea from direct blows upon the eyeball are rare, but usually cause suppuration, keratitis, or abscess, and become one of the most dangerous affections of the eye. Such results follow more frequently in aged persons than in the young, and arise from small objects striking the cornea directly, and as all abscesses or suppurations of the cornea are followed by some opacity, the vision thereby becomes defective. In the treatment, cold applications, and Arnica are the first indicc,- 56 DISEASES AND INJURIES OF THE EYZ. tions. If suppuration becomes established, the temperature of the applications must be changed, and thin compresses wet with a hot infusion of calendula flowers applied for half an hour at a time several times a day, and the administration of Hepar or Silicia may assist in improving the condition. The presence of pus in the anterior chamber may necessitate para- centesis to draw off the aqueous and thus lessen the tension. The cornea is frequently the seat of incised wounds resulting from explosions, direct cuts or thrusts from various objects. If the wound is merely an incised one, it may be extensive without necessarily destroying the vision; however, if the wound is at all extensive there is loss of the aqueous humor, and frequently prolapse of the iris into the wound; where there is no hernia of the latter present, the eyelids should be closed, after the instillation of a drop of atropine, and a bandage applied, the patient being confined to the bed and every effort made to give the organ absolute rest, and thus facilitate the union which takes place in a few days. If there is prolapse of the iris, it is not advisable to attempt to return it to the anterior chamber by any manipulation, as the pressing of these delicate parts results in iritis and further complicates the case. The projecting portion of the iris may be cut off close to the cornea with a pair of curved iris scissors. If the iris is caught in the wound during the progress of healing and bulges by reason of pressure from the aqueous behind it, it should be punctured with a cataract knife until by gradual contraction it heals without projection; sometimes the iris tissue degenerates into a cystoid condition which will require opening with a cataract knife, and close dissection with fine scissors of the tissue down to the cornea, the appli- cation of a bandage, and maintainance of rest until the wound again heals. Small incised wounds of the cornea, if no other portions of the eye are injured, are almost harmless, as they heal very rapidly. Wounds of this portion of the eye are more frequently complicated by contusion, hemorrhage, prolapse of the iris, wounds of the lens or deeper structures, and hence become much more grave. INJURIES OF THE SOLERA AND IRIS. 57 INJURIES OF THE SOLERA. Wounds lying in the sclera are, as a rule, much, more dangerous to the integrity of the eye than corresponding ones of the cornea. The unyielding nature of the fibrous tissue of the sclera and the prolapse of the vitreous prevent the edges of the wound from coming into close apposition, and hence it heals with difficulty. Fine sutures may be introduced and the wound brought together, with very excellent results in some cases. Rupture of the sclera may result from direct compres- sion of the eyeball, as in a blow from a closed fist, blunt instrument or a fall. The seat of rupture is usually at the upper and inner portion near the junction of the cornea, or between the cornea and insertion of the recti muscles. If sufficient to occasion a rupture of the sclera it will cause severe injuries to the other structures of the eyeball, the lens frequently being driven out through the opening, the vitreous may follow, and the eyeball collapse. Again, detachment of the choroid or retina may accompany the injury from rupture of the blood-vessels of the choroid. Wounds of the sclera become dangerous from the fact that the ciliary body, choroid and retina may prolapse in the wound during the process of healing and cause sufficient irritation to set up sympathetic irido-choroiditis in the other eye, and necessitate the removal of the injured eyeball. Hence the prognosis should be very guarded, as often in slight cases of detachment of the retina, degeneration of the vitreous and other more remote changes may result. In cases where the lens, choroid, or ciliary body are prolapsed in the wound and the eyeball collapsed it is better to remove the eyeball at once as it has already become sightless. In some cases of rupture of the sclera, the wound may lie towards the posterior portion and thus be hidden from inspection. The lessened tension, which is always present in ruptures of the sclera, will cause us to suspect it in this case. INJURIES OF THE IRIS. Wounds of the iris are usually accompanied by injuries to other structures. The prolapse in cases of wounds of the 58 DISEASES AND INJURIES OF THE EYE. cornea has already been considered. Incised wounds of the iris alone are extremely rare. When occurring they cause an effusion of blood into the anterior chamber, which obscures the iris. This blood is usually absorbed in thirty-six hours, when a cut will be found at the place of injury, as the wound does not unite, owing to the absence of inflammatory action in this case and the separation of the parts. Rest and quiet of the eye are necessary until the blood has been absorbed, when the extent of the injury can be ascertained and the prognosis made accordingly. Detachment of the iris from the ciliary body, in whole or in part, may occur from injuries affecting only the iris or also involving the cornea. Blows received upon the eye may cause a separation of the iris from a portion of the ciliary body ; after the effused blood has been absorbed, a second pupil, as in Fig. 28, will be observed, but that portion of the pupil will be irregular, and the iris, from laceration of its nerves and muscles, will not respond to the stimulus of light ; the vision will be somewhat impaired by the increased amount of light which is thus ad- Fia.28. mitted to the eye causing confusion of the retinal image. He-attachment of the iris is not possible, but rest should be enjoined until the eye has recovered from the effects of the blow, or of deeper injuries, such as detachment of the retina, which may complicate the case. A complete detachment of the whole of the iris may occur, as it has in two cases which have come under my notice : the first, where the iris was injured by a thrust from a wad-remover, which caused a lacerated wound of the cornea and removed over two thirds of the iris, the remaining portion being prolapsed in the wound. In the second case the cornea was incised by a cut from a broken bottle, and the iris pro- lapsed, and was removed entire by the unskillful attempt to remove the prolapse. Foreign bodies which pass through the anterior chamber often lodge upon the iris, where they rarely become encysted, though I have seen one case in which INJURIES OF THE LENS. 59 a bit of wood remained encysted in the iris for several years without causing trouble. Foreign bodies in this region are readily discovered by focal or oblique illumination. If a foreign body has lodged upon the iris, an opening in the cornea should be made with an iridectomy or cataract knife, the iris forceps introduced, and the portion of the iris contain- ing the foreign body seized and brought out, the iris then, excised, atropine solution introduced, and the eye bandaged. No delay in the removal of foreign bodies should occur here, and if the eye is already inflamed an operation is still more imperative. If the foreign body consists of iron or steel, an. opening into the anterior chamber may be made, when the introduction of the point of a magnet into the wound may be sufficient to attract the particle, and upon withdrawal of the magnet the bit of iron or steel follows. All injuries of the iris, whether from incised wounds or foreign bodies, require the instillation of a solution of atropine, four grains to the ounce, to dilate the iris ad maximum and retain it there until all symptoms of inflammation have disappeared. The dilata- tion of the pupil will also enable us to form a prognosis, as a wound of the lens at a part covered by the iris in its undilated state may thereby be revealed, and thus affect our prognosis and cause a change in the line of treatment. INJURIES OF THE LENS. Ruptures of the sclera from blows may cause at the same moment loss of the lens from the eye, or if the conjunctiva remains intact, the lens becomes dislocated beneath it. The sac of conjunctiva thus formed may also contain blood, vitreous or prolapse of the iris. The tension of the eyeball is lessened and it feels soft under the pressure of the fingers. The lens usually gives shape to the sac and renders diagnosis, more easy. If the anterior chamber is clear, the loss of support of the iris from the absence of the lens gives it a tremulous appearance, and if the iris is prolapsed distortion of the pupil follows. The anterior chamber, however, ia t>U DISEASES AND INJURIES OF THE EYE. frequently filled with blood and obscures the condition of the interior. The prognosis is usually unfavorable; the lens may be removed by an incision from the conjunctival side, or allowed to become absorbed without removal, and if no more serious injury of the eyeball has been sustained, recovery may be good. The treatment consists in placing the patient in a recumbent position, and in preventing motion of the balls by a bandage, applying cold, and avoiding all muscular effort of the face as in chewing, coughing or straining at stool. If the lens is only partially in the wound and presses upon the iris, it should be removed; otherwise it is better to delay the removal of the lens until the scleral wound is healed. Suppurative inflammation of the globe may be the result of an injury of this kind and will require the treatment to be described further on. Dislocation of the lens may be partial or complete ; if forward into the anterior chamber it should be removed promptly or increased tension follows, and the pres- sure upon the iris existing for any length of time causes inflammation of its structure which rapidly extends to the choroid. If the dislocation is backward into the vitreous, the lens may be allowed to remain undisturbed and may become encysted or absorbed. Punctured wounds of the lens, if of slight extent, may cause opacity of a small portion of it. If the capsule of the lens is lacerated to any extent from this cause traumatic cataract results. I have seen Cannabis indica and Conium clear this up, where medication followed immediately after the injury. The operation of discission will be demanded at some future time, or if the lens becomes much swollen, and extrudes from its capsule into the anterior chamber, from imbibition of the aqueous through its torn capsule, the pressure thus made upon the iris may endanger inflammation, and the removal of the whole lens in its capsule may be necessary to prevent the transmission of sympathetic trouble to the other eye. Foreign bodies may lodge upon the capsule or enter the lens and thus produce an opacity of its structure, or blows received upon the eye may cause traumatic cataract by rupture of its INJURIES OF THE VITREOUS. 61 capsule at tlie periphery. Foreign bodies in the lens rapidly produce a cataractous condition and occasion inflammation which may extend to the iris and choroid, and thus cause sympathetic cyclitis of the other eye. In all cases of injury to the lens, the iris should be dilated and the eye kept at rest by a pad or bandage, and if inflammatory symptoms super- vene, it will be necessary to etherize the patient and make an iridectomy and remove the lens, upon the occurrence of any marked increase in the tension. The changes in the trans- parency of the lens, in injury to the eyeball, may not follow for some days or weeks after the accident has occurred. INJURIES OF THE VITREOUS. Among the accidents occurring to the vitreous humor after concussion or punctured wounds beyond the lens, is hemor- rhage from the ruptured blood-vessels of the choroid. The vision is quantitative, the patient being able to distinguish between light and darkness only. It is important to ascertain the extent of the field of vision, to enable us to determine whether there has been detachment of the retina or choroid. Owing to the impossibility of examination with the ophthal- moscope, we can only determine this by testing the patient in a dark room with a lamp or candle, which is held four or five feet from him, and the position of which is changed so as to define the field of vision, which, if found to be good, indicates no detachment of the retina. If the field is very dim above and clear below, partial detachment of the retina is diagnosed, or if the field is absent, total detachment may have occurred. Hemorrhage into the vitreous becomes absorbed very slowly, four to six weeks usually being required to clear up the blood, a floating scotoma resulting from the fibrin of the blood not infrequently remaining behind. Rest of the eye and a com- press bandage are indicated, while the internal administration of Arnica, Hamamelis, and Crotalus will hasten absorption. Foreign bodies, such as fragments of percussion caps, grains of shot, small metallic chips, glass or stone find, after passing DISEASES AND INJURIES OF THE EYE. through the cornea or sclera, a resting place in the vitreous humor. These bodies, if very small, occasionally become encysted and tho eye escapes immediate harm, but sooner or later the eye is lost, and there is only the question of imme- diate removal of the eye, or its removal at some future time when the condition demands it. If the foreign body is of large size, no time is to be lost in the enucleation of the eye, as the danger of sympathetic inflammation is very great. The position of bodies in the vitreous may be determined by the ophthalmoscope, if the media are clear and they lie not too far forward; usually, however, the passage of foreign bodies through the vitreous sets up an inflammation of this tissue and consequent opacity. Frequently they pass through the vitreous, and rebounding lodge upon or in the ciliary body where they rapidly excite destructive inflammation and require the early removal of the eyeball. Where particles of iron or steel enter the eyeball, they may be removed by the aid of Xnapp's foreign-body hook (Fig. 29), or a magnet, the point FIG. 20. of which is inserted through the wound of the cclerr., if present, or if the position of the chip can be determined by the ophthalmoscope an incision may be made through the sclera beneath the foreign body, the point of the magnet introduced and the foreign body be withdrawn with it. It usually hap- pens that the particle is caught in the edges of the incision, whence it must be removed by a pair of fine forceps; in this way the eyeball may be retained, but the vision is almost always destroyed, either by the inflammatory process which follows, or from the effusion of fluid beneath the retina at the wound. If suppuration has begun about the foreign body the removal, while admissible, is generally impossible, and the eye must be enucleated. The accompanying cut (Fig. 30) shows Dr. Gruning's mag- net, which consists of several magnetized steel bars, fitted into FIG. so. INJURIES OF THE CHOROID AND RETINA. 63 malleable iron caps, and provided with a projecting delicate point. It is capable of sustaining a weight of 15 grammes, or 225 grains, and will attract chips of iron weighing from 1 to 50 centigrammes at a distance of 1 to 5 mm. in the vitreous. INJURIES OF THE CHOROID. The choroid may be ruptured by the reception of blows upon the eyeball without external injury to the sclera or cornea. Such injuries are accom- panied by hemorrhage into the interior of the eye- ball, followed by sudden and complete loss of vision, or passing between the choroid and sclera the hemorrhage causes a detachment of the former, or, if occurring beneath the retina, lifts up that membrane, and, if excessive, finds its way into the vitreous. These hemorrhages are rapidly absorbed under the use of Arnica, Hamamelis, Lachesis and Crotalus and rest for the eye, and frequently leave no trace except a displacement of the pigment layer along the line of rupture, which usually shows itself about the posterior pole of the eye. Inflam- matory changes in both retina and choroid may result. INJURIES OF THE BETINA. Injuries of the retina usually co-exist with those of the choroid and are mainly those of detachment from blows which cause effusion of serum or blood between the choroid and its tissue, and destroy sight in proportion to the amount of tissue separated. Its re-attachment after injury is rare; however, absolute rest in a recumbent position and bandaging, with the administration of Arnica and Gelsemium may accom- plish much. CHAPTEK V. EEEOKS OF EEFEACTION. REFEACTION. The refraction of the eye is the ability which its media possess, when the eye is in a state of rest, to bring parallel rays of light to a focus upon the retina -without muscular effort. Eays of light coming from a luminous body diverge in all directions from it, but at a distance of eighteen or twenty feet they are practically parallel, hence all distances beyond this point are considered infinite, and those within twenty feet are called finite. Parallel rays of light passing through a convex lens (-4 Fig. 31) in a direction parallel to its axis, are so converged that they are brought to a point behind the lens (-F 1 ) at a distance equal to the focal power of the lens. This point is termed the principal focus of the lens. The focal power of the lens depends upon the curvatures of its surface and the index of the refraction of the material of which it is composed. Substances differ in their power of changing the direction of the rays of light, and the measure of this power is called the index of refraction. When divergent rays of light (P Fig. 32) fall upon a convex lens near its axis 64 ERRORS OF REFRACTION. G5 and come from beyond the distance of its principal focns (F) they converge to a point (P 1 ) beyond the focal distance of the lens. The point (P) from which the light diverges to fall upon the lens, and the point ' (P 5 ) at which the rays are again FIG. 32. FIG. 33. united, are termed conju- gate foci. When parallel rays of light fall upon a concave lens in a direction paral- lel to its axis, they pass through and diverge from it as if they came from a point (F Fig. 33) on the inner side of the lens; this point (F) is the principal focal point of the lens and in concave lenses is a negative one. Where the length of the eye is normal, and the eye is in a state of rest, the layer of rods and cones in the retina forms the principal focus of the cornea and crystalline lens, which con- stitute the lens system of the eye and may be considered as a combined convex lens. The refractive power of the eye, then, is the ability which its media have of bringing parallel rays of light to a focus upon the percipient elements of the retina when the accommodation is relaxed. These rays of light, on being reflected from the retina, pass out from the eye in a parallel direction. The focal distance of the lens system of the eye is about f inch or 20 mm. measuring from a point in the anterior chamber; the focal length of the cornea being 31 mm. and that of the lens 43 mm. The length FIG. 34. f * ne optic axis, the line (FF f Fig. 34) 5 66 DISEASES AND INJURIES OF THE EYE. drawn through the center of the cornea to a point midway between the macula lutea (???) and the optic nerve entrance (o) is 24 mm., while the visual axis, the line (Vm] which joins the point of the object looked at with the macula lutea, measured from the cornea, is about 23 mm. These two lines cross at the nodal point (7t) of the dioptric media of the eye and form an angle which is called the angle alpha (a) and measures about 5, decreasing when the eye- ball is elongated as in myopia, and increasing when it is shortened as in hypermetropia ; the angle being determined by the position of the yellow spot in reference to the axis of the cornea. The nodal point (7c) is the optical centre of the eye and is situated near the posterior surface of the crystal- line lens. The angle formed by the crossing of the visual rays at the optical centre determines the size of the image formed on the retina. The nodal point changes with the effort of accommodation. It may be advanced or caused to recede by placing a convex or concave lens in front of the eye, when the retinal image is also affected, being increased by the former and diminished by the latter. EMMETBOPIA AND AMETKOPIA. The eye is said to be emmetropic when its refractive power is such as to bring parallel rays of light to a focus upon the retina when the accommodation is in a state of full relaxation, and also when it possesses the faculty of increasing this refrac- tion by the exercise of the accommodation to such a degree as to form well-defined images from divergent rays. The vision of such an eye is perfect for distance, and the use of even a weak concave or convex glass lessens the distinctness of the image. An eye to be emmetropic, or normal, must have an antero-posterior diameter of about twenty-three mm. ; if the axis is longer or shorter than this the eye becomes ametropic, and parallel rays, with the accommodation at rest, are not brought to a focus upon the retina, but either in front or behind it. In practice we do not usually employ atropine or other SPECTACLES. 67 mydriatics to paralyze the accommodation in determining the refraction, hence we must make allowance for this. An eye which is emmetropic has the vision made worse by the use of a convex glass, and the vision is not further improved by the use of a concave glass. If a convex glass placed before the eye does not disturb the vision or actually improves it, then hypermetropia is present; if it is improved by a concave glass then myopia becomes apparent. In Fig. 85, which shows the rela- r-r^^^ tive length of the hyperme- opic, emme- tropic and my- opic eye, the retina of the FIG. 35. , , hypermetropic H is in advance of that of the emmetropic JEJ, while that of the myopic eye M lies behind. Parallel rays from B B are brought to a focus in the hypermetropic eye at E, or behind its retina H, unless the accommodation is exercised, "while in the normal eye the focus is at E and in the myopic eye at or near E in front of its retina M. Divergent rays of light from C are brought to a focus at H and E by the exercise of the necessary accommodation in the hyperopic and emme- tropic eyes, and also at M in the myopic eye without the aid of the accommodation. Astigmatism, another form of ame- tropia, is only a combination in the same eye of different states of refraction, or of different degrees of the same form of ametropia. An emmetropic fundus in a direct examination with the ophthalmoscope gives a clear erect image at three or four inches from the eye. SPECTACLES. For the correction of the errors of refraction certain optical aids are used which are called spectacles. These consist of suitable lenses mounted in frames which hold them in proper 68 . DISEASES AND INJURIES OF THE EYE. position before the eyes. The lenses are made ordinarily from a good quality of crown glass, or transparent quartz, the so-called pebble glass. The former is more frequently used as it presents the same density throughout and is better adapted for the purpose of refraction. The latter is harder and less likely to become scratched, loui possesses no other qualities which would make it preferable to glass. The frames may be made of various metals or of rubber, shell, etc., which have their various advantages as regards weight, adorn- ment, etc. The spectacle frames are better suited to their use as regards shape, as the lenses are held firmly in position before the eye by the nose-piece which rests upon the bridge of the nose, and the temple pieces which press the sides of the head, or hook behind the ears. Eye-glasses are more suitable for temporary use, and being attached to the clothing are always at hand, ready for use. The glass should be placed aa close to the front of the eyes as possible and yet not have the cilia touch them. The centre of the lens should come directly over the centre of the pupil, unless it is desired in certain cases to get a prismatic effect also from the glass, which i& done by decentreing the lenses or placing them more widely apart. Lenses are ground of various kinds, those most fre- quently used being bi-convex, plano-convex, bi-concave, plano- concave, convex or concave meniscus and cylindric. Two systems of numeration for spectacle lenses are in vogue, the old or inch, and the metrical system. According to the old system a lens of one inch focus was taken as the unit and the glasses numbered accordingly; hence the focal length was expressed by using fractions; but as the inch is not a standard unit of measurement, differing in various countries, the metrical system has received much favor. In the latter system a lens of one metre, or 39.37 Eng. inches, focal length is taken as the unit ; for convenience it is called a dioptric and, for brevity, the symbol D is used. As the glasses most used are of a greater refractive power than the unit, the majority are expressed by whole numbers. A. lens of half a metre focus, would have twice the power of the unit,. SPECTACLES. 69 and its measure would be two dioptrics or 2D; of one-fourth of a metre, four dioptrics or 4D; of twice the length of a metre, one-half a dioptric or expressed decimally .5D. The H- sign before the number of dioptrics indicates a convex glass ; a concave lens, s. a spherical, and cyl. a cylindrical lens. The numeration of the old system can be approximately converted into the metrical system by multiplying the fractions of the old system by 40, which is nearly the length of a metre. For instance, a lens -^ X 40 = -fg-, or four dioptrics, 4D ; =2, or 2D. Conversely a lens of 4 dioptrics equals l ens f 10 inches focus. The following table gives the relative values of each: iV or a Focus in Inches. Number in Dioptrics. Focus in Inches. Number in Dioptrics. 160 0.25 9 4.5 80 0.50 8 5. 60 0.67 7 5.5 50 0.75 6/4 6. 40 1.00 6 6.5 36 1.11 5/4 7.5 30 1.25 5 8. 24 1.5 4 K 9. 22 1.75 4 10. 20 2. 3M 10.5 18 2.25 3/^ 11. 16 2.5 3M 12. 14 2.75 3 13. 13 3. 2M 14. 12 3.25 8j2 16. 11 3.5 *3 18. 10 4. 2 20. Spherical convex lenses are ground by the use of a concave tool which is a section of a sphere. Spherical concave require a convex tool for grinding, by which the concavity is ground into the glass. The common forms of lenses are as repre- sented in Fig. 36, viz., the bi-convex A, the plano-convex B, the convex-meniscus or periscopic C, the plano-concave E, and bi-concave D, and the concave meniscus F. Cylindrical lenses are formed by grinding a curved surface into the glass with a 70 DISEASES AND INJURIES OF THE EYE. E FIG. 36. cylindrical tool, so that in the direction parallel to the axis of the cylinder there is no curve, but at right angles to the axis, a curve is formed which is equal in focal length to the curve of the cylindrical glass desired. Although simply refracting- the light without formation of an image, they are numbered according to the laws governing spherical glasses ; they may- be plano-cylindric, bi-cylindric, or, when combined with, spherical glasses, sphero-cylindric. Care is necessary in set- ting cylindrical lenses in spectacle frames, as the slightest deviation of the axis of the glass from the> meridian which it is de- sired to correct will destroy the whole effect of the glass. Prismatic lenses simply cause a change in the direction of the light rays towards their bases, hence form no images, and have no foci. Those used for ophthalmic purposes are confined to some cases of muscular insufficiency and are very weak, two to three degrees, as with the increase of the refract- ing angle beyond this, the refraction of the rays increases and the diffusion of color becomes a serious inconvenience. STENOPAIC GLASSES consist of a small portion of transparent glass surrounded by an opaque surface, which prevents the entrance of rays to the eye, except through the narrow slit or circular opening; in cases where the cornea presents many- irregularities they may be useful for near vision, but the field being so much contracted by the minute opening they are rarely practical for distance. Protective glasses are usually colored glasses, blue or smoke, with or without refracting- curves, as desired. For purposes of protection simply, they should be large enough to well cover the eye, and, if neces- sary, additional glasses or other material should be supplied to prevent the entrance of light at the side, which is often more annoying than that falling directly upon the eye. The smoke-colored glass is much more suitable than blue glass, which only excludes the orange rays of light which have been RANGE OF ACCOMMODATION. 71 supposed to be particularly distressing to the sensitive retina. Practice fails to prove the peculiar value of blue glasses in the treatment of these cases. The use of protective glasses should not be indulged in more than is absolutely necessary, when the light is not dazzling, as prolonged use tends to increase rather than lessen the sensitiveness to light. KANGE OF ACCOMMODATION. If objects are brought nearer than a distance of twenty feet, the rays which fall upon the eye are no longer parallel but divergent, and the refractive power of the media brings them to a focus behind the retina at the conjugate focus. To bring this focus forward, then, so that it will fall upon the retina, the accommodation must be brought into use, which, by increasing the convexity of the anterior surface of the lens, increases the refractive power and shortens the focal distance until the image falls upon the retina and becomes distinct. As in Fig. 37, the upper half of which shows a normal eye in a state of rest, and the lower half *& a state (^ * of active accom- modation for a - 37 - near point at A. The divergent rays from A would be brought to a focus at O behind the retina R if the accommodation was not exercised, but the increased refractive power resulting from the increased convexity of the lens brings them to a focus at R. The point A represents the nearest point of distinct vision and is called the near point or punctum proximum (P). The greatest distance to which an eye can see is called the far point or punctum remotum (-B). The range of accommoda- tion (A) is the measure of the distance between these two points, and may be expressed by the formula: A = f R For convenience this is measured by the power of a lens neces- 72 DISEASES AND INJURIES OF THE EYE. sary to produce the same result. In the emmetropic eye this is equal to the distance of the object, measured in inches. PKESBYOPIA. During childhood the near point of accommodation is four inches or less, owing to the soft condition of the lens fibres and their consequent increased elasticity. After ten, up to twenty years of age, the lens becomes more firm, and as age advances the accommodative power diminishes, owing to the lessened elasticity of the lens and the loss of power of the cil- iary muscle, so that after forty-five years of age objects at less than eight or ten inches from the eye are not clearly focused upon the retina. This shortening of the range of accommo- dation or receding of the near point is, then, a physiological change which results from age. This loss of accommodative power is called presbyopia (-FV). When it has reached a certain degree the amount of accommodation necessary to see an object one foot from the eye is yV, that is ^ of that neces- sary to see at one inch from the eye. To see an object twenty inches from the eye would then require an amount of accommodation equal to a convex lens of ^. To see at an infinite distance would require one divided by infinity, -i- or no effort. The monocular or absolute range of accommodation is that obtained by testing each eye separately ; if both eyes are tried together the binocular range is obtained, and this is slightly less than the monocular. The relative range is that which we possess when the visual axes of the eyes are fixed upon some near object. The positive portion is that lying between the object and the eye and the negative that lying beyond the object The former may be measured by a concave glass, the latter by a convex glass. To exert the eyes for any near work there must always be a reserved amount of accommodation at a given point of convergence, or the eyes tire rapidly. To read comfortably for any length of time the positive portion of the relative range of accommodation must be, at least, one- PRESBYOPIA. 73 half the negative. The power of accommodation in infancy is ^ ; at ten years J ; at thirty-five ^ or less ; at forty-five it is seldom more than -^ ; at fifty y 1 ^ ; at sixty it is -fa. DIAGNOSIS. An arbitrary standard of eight inches has been selected by Donders as the near point in the normal eye, hence presbyopia appears as soon as the accommodation falls short of ^, as for fine work that amount becomes necessary. The age at which presbyopia appears depends upon the gen- eral condition and upon the shape of the eyeball. If the patient is debilitated, or the eyeball too short, it will appear earlier than if the patient is robust; or, if the eyeball be too long, it will be delayed. SYMPTOMS. The symptoms which indicate a condition of presbyopia are first, difficulty in reading fine print with arti- ficial light, followed by a sense of strain in using the eyes for near work at all times. Frequently this condition is accom- panied by an irritable state of the eyes and smarting of the lids. These symptoms arise from the fatigue of the ciliary muscle resulting from the effort to maintain the accommoda- tion at a nearer point than its power will permit. If now the range of accommodation is tested, it will be found that the near point has receded eleven or twelve inches. The reason that this condition manifests itself in the evening is because the pupil is more dilated than in daylight, and the larger the pupil the more indistinct objects become when the focus is not exact, as the circles of diffusion become much greater. The eye cannot sustain the accommodative effort necessary under these circumstances without weariness and consequent eye strain, hence the relief to be obtained from the use of a convex glass should not be delayed. In fact, the early use of glasses to relieve the strain, results in giving comfort to the eye, retains the strength of the eye for the future, and, at the same time, lessens the rapid increase of the presbyopia. On the other hand, if the proper glasses are not used, the presbyopia increases more rapidly, and the ciliary muscle is often permanently weakened. TKEATMENT. No general rule can be given for the deter- 74 DISEASES AND INJURIES OF THE EYE. ruination of the proper glasses for use, or at what time they should be put on. In prescribing glasses for presbyopia, we must take into account the distance at which the patient is in the habit of using his eyes, and the kind of work for which they are employed. The reading, or sewing distance, varies, with individuals according to their habit, stature, and the sharpness of vision. The tall man will read comfortably with his book at twenty inches from the eye, while the small woman finds her needle work in the proper position at eight or ten inches away. The glass obtained, then, by calculation, is not always the practical glass: for example, if the near point is found at eighteen inches, and it is desired to see the object at twelve inches, then -rV~TV~ TS > this, then, should be the glass needed, but a trial with it at 12 inches at once determines that it is not to be worn with comfort, while -$ is, because in this case the positive amount of accommodation at 12 inches is not ^ that of the negative with -^ at that distance, hence it must be increased. Again, the strength of the glass may, according to the individual, have to be diminished, and perhaps -$ would suit much better. Suppose a patient of sixty complains that he can no longer read with comfort, espe- cially in the evening. He reads ordinary print at thirty inches,, but not nearer; his former reading distance was fifteen inches, then TV~'sV == "ru"5 with a +30 he reads at the former distance, but finds that the glass does not yet make his reading a. pleasure, and on trial a +2-4 is found to suit him perfectly. The rule, then, for the prescription of glasses in presbyopia is to give that glass which makes ordinary print plain at the usual reading distance of the patient, and can be worn with comfort; ordinarily the first glass which is necessary for pres- byopia is from ^ to ^ and the change necessary will amount to -^g or -^Q- for each two years for patients under sixty years of age. After sixty the glass must be changed more fre- quently, as the increase in the presbyopia is nearly double that of the ten years preceding. It is important to bear in mind that the weakest glasses which enable a person to do his work give him the longest range of accommodation. If the PRESBYOPIA. 75 glasses required are too strong, say -|- or -j^, and the accommo- dation is very much weakened the range of accommodation is necessarily shortened, and patients who wear such glasses are apt to complain because a change of position of the work, or a motion of the head, throws it out of focus. Under these cir- cumstances the patient must be satisfied with the inconven- ience, or be content to see at a greater distance with a weaker glass. The presbyopia of ametropic eyes must be corrected by first correcting the ametropia and then obtaining the near point. In hyperopia, the presbyopic glass is added to that for the cor- rection of the hyperopia. For example, if there is a hyperopia of -fa in a patient of fifty, he requires his near point to be brought up to twelve inches. A convex glass of -fa is placed in front of the eye and a glass of % is placed in front of the other glass. If this does not accomplish the result a weaker or a stronger glass may be required ; if, however, this is the proper glass, then Tg-+2T i"V or a convex 16 ' will be required for near vision. In myopes, from habit the working distance is close to the eye, and they prefer a glass which will enable them to see at about nine inches. If the myopia is -J-, then -J- -J= j^-; in. this case, the patient would have to use a weaker concave glass for near work. If his myopia was -J- he would require no- glass; if % he would require, if he desired to work at eight inches, a +24; thus ^- T8 := T ^ ne amount of presbyopia if the eye was normal, but being myopic the glass then should be T 1 "B~~Tg"~2T ^ e convex glass which would give him comfortable vision at eight inches, while the distant vision would still require the use of the concave glass which cor- rected his myopia. The failure of the accommodation .is not always due to normal causes, but is often an indication of disease, as in glaucoma, where the rapid loss of accommodation is one of the earlist symptoms ; also in paralysis of the external rectus muscle, a paretic condition is often observed, and in some cases of beginning cataract there is frequently a rapid failure DISEASES AND INJURIES OF THE EYE. of the accommodation. Before prescribing glasses for pres- byopia, investigation must decide whether the presbyopia is apparent or real. HYPERMETKOPIA OR HYPEROPIA. Hypermetropia or hyperopia (H) is a condition in which parallel rays of light are not brought to a focus upon the retina unless the accommodation is brought into use. It depends upon the antero-posterior diameter of the eyeball being too short, less than 23 mm. Under these circum- stances the focus of parallel rays is behind the retina, and distant objects are not seen when the eye is at rest. This anomaly of refraction is dependant upon a congenital flatten- ing of the eyeball, and was described by Donders in 1848. In connection with the congenital form resulting from the want of proper development, there is frequently a certain loss of vision, or amblyopia, due to the same cause. Hyperopia may be acquired by diseased conditions or opera- tions upon the cornea which result in flattening of its normal curves. The highest degree of acquired hyperopia is that following the removal of the lens in cataract operations or from injury, and also from the physiological changes in the refractive index of the cornea and lens which occur after sixty years of age. Hyperopia presents one of the most common forms of refractive error. In 870 school children examined T>y the author 523 were found hyperopic, while only 105 presented a normal refraction. DIAGNOSIS. In the majority of cases of hyperopia the exercise of the accommodation masks the condition so that careful testing -of the distant vision with convex glasses, as ~well as examination with the ophthalmoscope, becomes neces- sary to determine the condition. Oftentimes the facial condi- tion of the patient will indicate the probable presence of hyperopia, as the eye appears flatter and smaller, and with this there is an accompanying want of full development of the face, particularly in the malar region, and the nose bridge also freqiiently presents a flattened condition. HYPERUETROPIA OR HYPEROPIA. SYMPTOMS. Patients with hyperopia complain that in read- ing, writing, and all near work, particularly in an artificial or dim light, the vision, although at first clear, soon becomes blurred, and it becomes necessary to stop work for a time until the eye regains its power. A few moments' rest will enable them to see distinctly again for a short time, when the feeling of fatigue and blur, and perhaps pain over the orbit, again demands rest of the overtaxed eyes. An examination of the eye shows conjunctivitis, palpebral hyperaemia or blepha- ritis, or perhaps no external appearance of disease is present Again, the patient avers that there is nothing wrong with the vision, but that the eyes appear weak when he attempts near work, and pain over the brow, severe headaches, or nausea, vomiting, or vertigo, may appear as the result of a strain in the hyperopic condition. As a rule the amount of hyperopia present bears no relation to the amount of accommodative reflex disturbances which arise in these cases, as oftentimes, a. high degree of hyperopia gives but slight, if any, incon- venience beyond some general indistinctness of vision and the earlier appearance of presbyopia; whereas in other cases the slightest degrees are often the cause, in less robust and more neurasthenic patients, of severe disturbances. The close application of the eyes for near work, other things being equal, will always hasten the appearance of these symptoms of asihenopia, or weak sight, which are either from the weakness, of the accommodation, accommodative asfhenopia, or from weakness of the recti muscles, termed muscular asthenopia, which as frequently accompanies the condition. The cause of these symptoms lies in the unconscious effort of accommodation which the patient is constantly making to increase the convexity of the lens, and thus increase the power to bring the rays of light to a focus upon the retina, instead of behind it, which the defective refraction of the eye would do. By the active effort of the accommodation he is just able to focus the rays so that distant vision is rendered clear, but for all near objects, the rays being divergent, an extra increase of the accommodation becomes necessary, _so _ that during the DISEASES AND INJURIES OF THE EYE. Awaking hours the accommodative apparatus is constantly in use, and consequently soon tires under the continued strain. The effort to perform the extra labor thus thrown upon the ciliary muscle results in hypersemia of the ciliary body and a generally irritable condition of the eyes, conjunctivitis, blepha- ritis, etc., and in many cases severe reflex symptoms from irritation of the terminal branches of the ciliary nerves in the ciliary body, simulating cerebral disturbances, not infrequently appear. The condition of the health and the amount of near appli- cation have much to do with the time of the appearance of the symptoms due to hyperopia. If a person has a well-toned muscular system, together with an increased development of the circular fibres of the ciliary muscle, which occurs in this case, as discovered by Iwanoff, he may make no complaint of trouble arising from defective refraction. If, however, the health fails, or, as frequently happens, the complaint follows prostrating fevers, the puerperal condition, mental shock, uterine affections, or the use of the eyes for reading during con- valescence or while in a recumbent position, or a constant strain of the muscle necessitated by prolonged work at near or fine objects, as in reading, writing, drawing etc., the power of the -accommodation rapidly deteriorates and aid is sought. DIAGNOSIS. With the ophthalmoscope, if the mirror alone is used, a rapid diagnosis of hyperopia may be made; the fundus is seen at a greater distance, 18 to 24 inches, than in the opposite condition, myopia, and we have an erect image, which, as in keratoscopy, moves in the same direction as the movement of the observer's head or the rotation of the mirror. In the direct method the fundus is not visible in the close approximation of the eyes, unless the accommodation of the observer is exercised. If the accommodation be relaxed and the observer emmetropic, or a proper correction made, the convex glass rotated into position behind the mirror which gives the distinct vision of the fundus, will give also the degree of hyperopia, when the mirror is brought as close as half an inch from the cornea. If the distance is greater, or HYPERMETROPIA OR HYPEROPIA. 79 1^ inches from the nodal point of the observed eye, then the number of the lens of the ophthalmoscope is stronger by the increased distance, represented by a lens equal in focal length to that distance. If an examination at 1^ inches shows a hyperopia of ^, then a lens of 1 in. focus must be deducted, .giving the amount of hyperopia as \ The image recedes the nearer you approach the eye, and at the same time a larger portion of the fundus becomes visible, because the rays from the hyperopic eye are divergent, and the nearer you approach the eye the more rays are obtained by the eye of the observer.. The image appears to recede because we estimate the distance by the size of the image. In the indirect method the image is larger, but a smaller portion of the fundus is seen. Here the divergent rays coming from the eye are caught by the object lens, and are brought to a focus further behind the lens and nearer to the eye of the observer, and more rays are collected from the inverted image thus formed. In the eminetropic eye the vision is disturbed by placing in front of it a convex glass and is not improved by a concave glass, but a hyperopic eye, even if the distant vision as deter- mined by the card of test letters is perfect, will permit the use of a convex glass without disturbance, and if the distant vision be not normal, an improvement follows the use of a proper convex glass. The hyperopic condition can thus be determined in a practical manner by the use of test types and convex glasses. If, then, the patient is placed at the proper distance for the test card* as twenty feet for No. XX, and con- vex glasses are placed before the eye, the strongest convex glass with which he reads No. XX is the measure of his hyperopia. Thus, if, beginning with a -f -- and following with a stronger glass until +5^ is reached and the print remains or is made distinct, while the next stronger glass blurs the letter, his hyperopia thus determined is ^ ; this amount of H thus dis- covered is tanned manifest hyperopia (Hm], and is not usually the full measure, as the ciliary muscle from constant strain does not relax, and the eye still accommodates somewhat even when the convex glass is placed before it. The H which thus 80 DISEASES AND INJURIES OF THE EYE. remains undetermined is termed latent H and only becomes known after the ciliary muscle is paralyzed by atropine or some other mydriatic. The strongest glass which then enables the patient to read the test type at the proper distance is the measure of the total amount of hyperopia (Ht], and is equal to the sum of the manifest and latent hyperopia. If before the use of the mydriatic the test showed the Hm ^ and after the accommodation was paralyzed the Hi was -^3-, then the HI is the difference between ^ and 3^, or ^. Usually the HI is greater than the Hm, particularly in children and young people. In practice it is not necessary to paralyze the accom- modation to obtain the full amount of H, as it is approxi- mately determined by the ophthalmoscope, and each eye should be tested separately, and the strongest glass which is borne is the practical measure of the Hm. If the glass during the testing is held for a few moments before the eye, the accom- modation relaxes somewhat, so that a more accurate result is obtained. The refraction of the two eyes is thus found to differ in many cases and it may be advisable to give the glasses which correct the refractive power of each eye. Donders, to whom we owe the knowledge of the character and symptoms of hyperopia, makes a further classification of the kinds of hyperopia into facultative, where the patient sees equally well at a distance with or without convex glasses; relative, where distant vision is good without glasses, but is accomplished by a convergence of the optic axes to such an extent as to produce a convergent squint, owing to the relation existing between the accommodation and the convergence of the optic axes; and absolute, where neither distant nor near vision is distinct without convex glasses. This further division possesses no practical importance and is but little used. In hyperopia advanced age causes the demand for glasses early, at thirty or thirty-five, owing to the gradual impairment of the power of the ciliary muscle ; after forty this, together with the loss of the elasticity of the lens, demands the use of a glass to correct the presbyopia as well. In some cases the prolonged tension of the ciliary muscle in its efforts to lespond HYPERMETROPIA OR HYPEROPIA. 81 to the frequent calls made upon it, results in the production of a spasmodic contraction of the muscle which causes spasm of the accommodation. This condition occurs more often in weak degrees of hyperopia, as -fa to -g^, and may mask the true condition by simulating myopia, and the use of convex glasses will be refused, while a weak concave glass is worn at the expense of still greater tax upon the accommodation. This condition will be more fully considered in the affections of the ciliary muscle. Hyperopia is the common cause in the production of convergent stra.bJRrrmg, since the act of accom- modation is associated with contraction of the internal recti muscles, and can only be exercised to a limited extent without converging the optic axes, and as the ciliary muscle is in a state of constant contraction, which must be still more increased for near objects, an increased convergence by the recti is brought about until the patient converges more than is necessary to fix the eyes upon the object, and as he can no longer see with both eyes, one or the other deviates inward, while the other fixes upon the object accurately. In time this temporary deviation becomes fixed and convergent stra- bismus results. TREATMENT. The treatment of hyperopia consists in the prescription of convex glasses to correct in whole, or in part, the error of refraction, and thus relieve the ciliary muscle of the necessity of extra work. Fig. 38 represents a hyperme- tropic eye at A A /\ \\ rest, in which condition the convergent rays AA are refract- FIG - ^ ed to a focus upon its retina H, parallel rays BB being under the same condition refracted to a focus at the normal position of the retina E; by the interposition of a convex lens the parallel rays are rendered convergent and thus enter the eye in such a condition as permits the formation of a distinct image upon the actual retina H. The power of the lens 6 82 DISEASES AND INJURIES OF THE EYE. required, and the necessity for wearing it at all times, or only for near work, will depend upon the individual peculiar- ities of each case. In some cases where the vision is acute for both near and distant objects the accommodation does not seem to suffer from the prolonged tension. Here glasses may not be needed until the age of thirty or thirty-five, when the early appearance of presbyopia, as denoted by the removal of the near point beyond ten or twelve inches, will require a convex glass for reading. The convex glass which corrects the whole of the H would seem theoretically to be the glass to be worn, but practically this glass is too strong, as the ciliary muscle seems to have acquired a certain amount of tension which does not relax under the use of the glass. Hence the rule is to give that glass which corrects the whole of the_manifest jEf. qnd a part, usually one-fan rthj of fV>p 1fl.fcmf, The patient is asked to read No. XX of Snellen's test types at twenty feet distant ; he does so readily. Now place before the eyes a weak convex glass, say ^ B , and if the letters still remain clear try a still stronger one until we find he reads the test with -g 1 ^; try- ing the next glass we find that it blurs the vision somewhat. We have determined that his Hm is ^5 he is then asked to read No. 1 test type at twelve inches with this glass ; if he can do so with facility he is given this glass, a convex 30, which he is directed to use for all near work. Tested with the ophthalmoscope his H is found to be y 1 ^-; we have then cor- rected only part of his error. Now the glass prescribed may relieve his symptoms entirely, or it may be necessary for him to wear the glasses constantly for both near and distant vision. If the latter becomes necessary, then he will be required to change the glasses for stronger ones in a short time as they do not neutralize his latent hyperopia, and this will gradually become manifest, and his asthenopic symptoms will again appear and rg^uire a stronger _glasg. These changes will have to be repeated until after a few months the whole amount of H becomes manifest and is corrected. In^chikjr^n^t_is_better to correct the full amount as deter- mined by the ophthalmoscope, or lUiaer tiie paralyzing effect MYOPIA. 83 of atropine, as the vision, which is often poor in these cases, se^ms to improve from the apparent improvement in the tone of the eye resulting from the use of the glasses. In adults the correction of the whole amount as determined by these methods causes too much inconvenience. If in the test the distant vision is not acute but made so or improved by the convex glasses, then the full amount of H should be corrected and the glasses ordered to be worn constantly as a rule. The glasses should be continually worn in all cases where the H is more than ^ and in weakly subjects where it is even less than this, particularly if the recti muscles are weak. With the appear- ance of presbyopia, the patient will have to use two pairs of 1 glasses, one for distance which corrects his hypejcopia and a stronger one for near vision, which corrects both the hyperopia and presbypjria. In many cases of H, particularly of high degree, the vision is not made acute by any glasses, a certain amount of congenital amblyopia being present from the unde- veloped condition of the eye. In many cases the asthenopic symptoms occasioned by the over-strained and often irritable ciliary muscle do not subside upon the prescription of glasses, but will require some medicinal treatment. MYOPIA. Myopia (M] or nearsightedness is a condition exactly the opposite of hyparmetropia, the eye being too long, or more than 23 mm. in its antero-posterior diameter. Hence, parallel rays, when the eye is in a state of rest, are brought to a focus in front of the retina. If the accommodation is exer- cised it serves only to bring the focus of the rays still further in front of the retina. The far point of the myopic patient must then approach closer to the eye, as^an object to be per- ceived must be nearer to the eye than infinity, or twenty feet, so that the rays will be divergent instead, of parallel. The far point will thus approach nearer and nearer to the eye as the degree of myopia increases. Myopia is occasionally physi- ological or congenital. More frequently the tendency is 04 DISEASES AND INJURIES OF THE EYE. inherited, but it is commonly acquired, and, except in very slight degrees, is progressive with age. The stronger the degree of myopia the more liable it is to increase, especially between the ages of twelve and twenty-five years. The eye- ball is usually more prominent, from its egg-like shape, and its movements more impeded than in the emmetropic or hyper- metropic eye, and when the eye is directed inwards the outer canthus is filled by the lengthened eye-ball. The pupils are usually more dilated than in the normal eye, and when trying to look at distant objects the eyelids are partially closed, thus lessening the circles of diffusion on the retina and giving more distinct vision. CAUSES. The causes which give rise to myopia are, as yet, not fully understood. While it may be congenital, the ten- dency is often hereditary. It is most frequently acquired between the ages of seven and fifteen, very rarely appearing after twenty-five years of age. It is a diseased condition of the eyes occurring in childhood and early adult life, seldom increasing after twenty- five, unless from want of proper hygiene of the eyes, prostrating illness, general enfeeblement of the health and loss of tone of the muscular system. If the sight in childhood is imperfect from any cause, such as opaci- ties of the cornea and lens, choroidal disease or astigmatism, myopia is induced from objects being brought close to the eyes to obtain a larger image upon the retina. Myopia may be caused also by an increase in the refractive power of the lens or cornea. If the cornea becomes more convex, as in conical cornea, the focal point lies in front of the retina. In commencing cataract, a swelling of the lens or an increase ' in its t refractive power causes a certain degree of myopia, as also does spasm of the ciliary muscle, which pro- duces and maintains an increased convexity of the lens. The more frequent causes which determine the inception and progress of myopia are those arising from prolonged use of the eyes in looking at objects held a short distance away. The constantly increasing proportion of myopes among school children and students shows that defects in our educational MYOPIA THE PATHOLOGICAL CHANGES. 85 system have much to do with its origin and progress. The arrangement of the light and desks, the posture, etc., of the child or student, increase or lessen the tendency to this disease. The flickering, dull or otherwise poor light, or that coming from the side so as to throw a portion of the page in the shadow ; the lowness of the desk which requires a bent posi- tion upon the part of the child ; reading in the prone position, or after a hearty meal ; the imperfect print of text-books, or the difficult characters of music, Greek or German, with many others, are highly productive of many cases of myopia. The effect produced upon the eyeball which results in the elongation of its axis is explained upou the ground that all close application of the eyes is accompanied by an increase in the ocular circulation, and if the return flow is interfered with ty the position of the head while stooping over the book or work, choroidal congestion with increased intra-ocular tension results. This causes a predisposition to the softening of the choroid and sclera. Together with this, the effort to fix the eyes upon close objects is accompanied by strong efforts at convergence and accommodation. This produces pressure upon the eyeball by the tension of the internal rectus, which is counterbalanced by the external rectus, and the fluid pressure is transmitted to the posterior portion of the eyeball, which is unprotected, and a slight bulging of the sclera at this point results. If these efforts are prolonged and rapidly recur and the sclera is correspondingly weak, the stretching becomes permanent, and although the eye may have been originally emmetropic, or slightly hypermetropic, it may thus become myopic. It is evident that if the disease once be started it will tend to rapidly increase the lengthening of the eyeball and the degree of myopia. The proportionate elongation of the optic axis to the degree of myopia has been tolerably well determined by Loring and others and is as follows: an elonga- tion of .22 mm. produces a myopia of 5^; .27 mm. of -$', .37 mm. of -^ 5 -46 mm. of 3 * T ; .56 mm. of ^5 -63 mm. of -^5 .82 mm. of T J T ; .97 mm. of T V; 1.06 mm. of ^5 1-1? mm - ^ Tin 1.31 mm. of ; 1.5 mm. of ; 2.07 mm. of ; 2.56 mm. of 86 DISEASES AND INJURIES OF THE EYE. 3.34 mm. of ^; 4.81 of j; 8.61 mm. of ^. Very slight degrees of myopia are thus seen to be attended by an apparently insignificant increase in the length of the eyeball, only .5 mm. up to -^j. The effect, however, has been a serious one to the patient, as his far point has been brought from infinity to within twenty-four inches of the eye. As the elongation of the eyeball increases, the far point rapidly approaches the eye, as in a myopia of ^ the eyeball is lengthened 5 mm. or 2^ lines, and the far point is now but three inches from the eye. In some cases the myope may derive some compensation from the fact that he sees more distinctly and works at a closer Tange with more comfort than an emmetropic eye, because he does not use his accommodation ; but, contrary to the popular idea, the myopic eye is not a strong eye, but a diseased one, and but few of its many subjects ever have even the satisfac- tion of comfortable near work. THE PATHOLOGICAL CHANGES in the choroid, sclera and retina become apparent even in the slighter degrees of myopia, as we frequently find them in -fo or less, while they become much more manifest and more grave with each additional degree of elongation. These changes consist in a stretching of the sclera, choroid, and retina, and a consequent atrophic con- dition of the delicate tissues of the latter. The sclera is expanded and thin throughout its whole extent, on the tem- poral more than on the median side, and more markedly at the posterior pole than elsewhere, as shown in Fig. 39, which represents a section of a strongly myopic eyeball with posterior bulging. These changes affect particularly the optic nerve entrance, causing a displace- ment of the optic nerve somewhat to the nasal side. A separation of the two nerve sheaths takes place in close proximity to the optic nerve entrance, as the outer sheath MYOPIA THE PATHOLOGICAL CHANGES. 87 FIG. 40. is continuous with the outer portion of the sclera, the inner sheath being closely united to the nerve. The subarachnoidal space becomes much wider and the posterior portion of the eyeball presents a conical appearance. The thinned sclera sinking into this space constitutes the so-called posterior staphyloma, which becomes very apparent in high degrees of myopia. The anterior portion of the choroid remains normal, but as it approaches the expanded portion it becomes thinner and atrophied. There is in the majority of cases a slow inflammatory condition of this portion of the choroid, which has been termed sclerotico-choroiditis posterior. This results in the thinning of the portion of the choroid adjacent to the optic disc, until it appears as a transpar- H~ ent membrane devoid of blood-vessels and capillaries, so that the white underlying sclera becomes visible. This choroidal atrophy may present the appearance of a crescent about the optic disc as in Fig. 40, and usually appears on the temporal side, and, extending towards the macula lutea, gives to the optic disc a jagged and irregular appearance. In high degrees of myopia the atrophic portion encircles the whole optic disc as in Fig. 41, and gives to it a much larger appearance than normal. If the myopia progresses rapidly other portions of the choroid become involved in the inflammatory process, and atrophic patches result; or the vitreous becomes involved and opacities of varying size appear, which interfere with the vision of the patient; or the vitreous itself may become fluid. If the opacities are very fine and diffuse, the patient will be annoyed by the muscce volitantes which myopic patients frequently complain of, although no impairment of the vision results. These floating specks often indicate an increase in the myopia. If the opacities are larger or float through the liquid vitreous, FIG. 41. 88 DISEASES AND INJURIES OF THE EYE. they interfere very materially with the vision. The retina, in participating in the choroidal stretching, lessens the visual acuity by the disturbance of its elements. The rods and cones being stretched apart occasion breaks in the outline of objects, a condition termed metamorpliopsia, and the retinal vessels also become more prominent and straighter in their course. Being loosely attached to the choroid, the retina is liable to detachment, particularly in high degrees of myopia, when its natural support, the vitreous, is lost by the changes which take place in it. This forms one of the most grave complications arising in myopia. Other changes which result from this disturbance are retraction of the iris, lens and anterior portion of the ciliary body, the deep- ening of the anterior chamber in myopia being thus accounted for. The nutrition of the lens may also be affected, and cata- ract, usually beginning at the posterior pole, follows. These results arising from the diseased condition of the eye, render the early recognition of myopia and its proper treatment of the utmost importance to the patient as regards his future vision, as these changes frequently develop after slight injuries, prolonged use of the eyes in reading or in near work, and the use of improper glasses, and again arise without apparent cause and progress until the vision is partly or com- pletely lost. The symptoms which accompany these changes may be very slight; there is usually, however, more or less sensitiveness to light, which may increase to such a degree as to demand entire exclusion of light from the eyes. The eye presents an irritable appearance, and intense pain may accompany its use, though more frequently the pain is described as of a dull, aching character, and is often referred to the orbit. DIAGNOSIS. The diagnosis is readily made by testing the far and near points of vision. If the patient cannot see distant objects and can read No. 1 Jaeger or 1^ Snellen of the small types well, but not beyond eight inches, this is evidently his far point, and if he cannot read the ordinary test types for distance, a concave glass is tried and the weakest concave glass MYOPIA DIAGNOSIS. 89 with which he gets the best vision is the measure of his myopia ; thus, if he cannot read the test type without a glass, but can do it with a concave ^, then his myopia is ^ ; or, if the removal of the glass somewhat from the eye does not lessen the vision, the glass is then too strong and a weaker one must be tried. If, however, this glass seems to suit the different objects, he is myopic ^, and a concave ^ placed in front of such an eye will cause parallel rays to be divergent as if they came from a distance of only eight inches, and would thus make distant objects distinct The ophthalmoscope affords a ready and accurate method of diagnosing this trouble. If the mirror is used without the lens at eighteen inches or two feet from the patient, an inverted image is seen which moves in an opposite direction to the move- ment of the head of the observer. This is due to the crossing of the emergent rays before .they meet his eye. If now the mirror is brought close to the eye, the weakest concave lens which will show the smallest retinal vessels near the disc will give the degree of myopia, provided the observer's accommo- dation is relaxed. The change in the fundus which is discov- erable by the ophthalmoscope, is the choroidal atrophy about the optic nerve, as already stated. This is usually crescentic and on the temporal side, but may appear on the other side, or encircle the whole disc. In keratoscopy the image of light and shade moves in the same direction as that in which the concave mirror is rotated, and the rapidity of movement and curvature of the shadow are the same in all meridians in cases of simple myopia. TREATMENT. The treatment of myopia should be both prophylactic and palliative or corrective. In the prevention of myopia and lessening of its progress much may be accom- plished by the proper care of the eye. There is no doubt that myopia is produced, or at least greatly increased in school children by want of proper arrangement of the light, the height of the desks, and the print of text-books. The light should be good, the seats so arranged that the light comes from the left, and the desks of such a height as to remove the 90 DISEASES AND INJURIES OF THE EYE. temptation to stoop. Beading or writing in a dull or flicker- ing light must not be permitted, and the amount of reading must be regulated, as this class of cases are apt to consume time in reading which should be used for developing the muscular system. Where a myopic tendency has been exhib- ited in children who have suffered from exanthematous diseases, reading and attendance at school should not be allowed until full bodily strength has been restored. Where vision is defective from astigmatism, or spasm of the accommodation is present, the correction by proper glasses should be made. In reading, the book should be held as far from the eye as possible and yet allow of distinct vision, and when the eye tires, the book should be laid aside and the eyes rested. In cases where the trouble is progressive and there is much choroidal congestion, the use of the eyes should be stopped until the condition improves. Atropine, by paralyzing the ciliary muscle, may prevent the rapid increase of myopia where it is accompanied by spasm of the accommodation. Such remedies as Agaricus, Belladonna, Gelsemium, Physostigma, Jaborandi, Lilium tigrinum and Duboisia, when properly prescribed, do much towards improv- ing the condition of the myopic eye by correcting the irregular action of the ciliary muscle. Other secondary disturbances of the optic nerve, retina, and choroid should be combatted by such remedies as Belladonna, Phosphorus, Gelsemium, Macrotin, etc. The palliative treatment consists in the use of proper concave glasses to correct the error of refraction. The manner in which concave glasses correct the error of refrac- tion is readily explained by reference to Fig. 42, which represents a myopic eye in a state of rest, and rays from its far point B are brought to a focus upon the retina at M. Parallel rays A A, however, are refracted to a focus at _E7, the position of the retina of an emmetropic eye, and in front of the myopic retina. If now the proper concave lens is placed upon the eye the rays A A are rendered convergent, and enter the eye in same direction as if coming from B, and are thus MYOPIA TREATMENT. 91 converged upon the retina at M. In mild degrees of myopia without tissue change, the weakest glass which gives clear vision of distant objects may be worn without danger, and have no effect upon the progress of the myopia. In all cases where the myopia is less than y 1 ^ the glasses should not be worn for near vision. In higher degrees than yV, the glasses may be worn for near vision, as they remove the near point farther from the eye and thus lessen the conver- gence of the FIG. 42. eyes and the tension of the recti muscles, so that patients are no longer tempted to stoop. These glasses must be weaker than those which are used for distance, from the fact that glasses which correct the whole myopia would require the exercise of the full accommodation for near objects, and as the accom- modation is usually weakened, the effort would only lead to overstraining and thus increase the trouble. If a patient with myopia reads No. XX test type with %, the weakest glass which makes the print clear, and it is desired to adapt glasses for reading music, sewing, or other special work at a distance of two feet, then the glasses desired will be lV-"2T =:: 2T' If tt 16 myopia is |, the far point then is only six. inches from the eye, and glasses will be required which will enable him to read at twelve inches; then ^ T V= T V will be the glasses required. Each eye should be tested separately, and when one eye is more myopic than the other, the least myopic eye decides the number of the glass. If different glasses are prescribed for the two eyes, the images formed upon the two retinae differ in size and cause confusion. The same glasses may be worn for both near and distant vision when the myopia is slight, the range of accommodation good, and the eya perfectly healthy. Glasses for near vision may also be given when the myopia is great, to prevent the convergence of the optic axes and lessen the tension of the "92 DISEASES AND INJURIES OF THE EYE. accommodation, and also where there is much asthenopia. Olasses should not be allowed in mild degrees of myopia, say T ^ iere i s pres- ent then a myopia of ^ , which will require a concave spherical glass of ^-g-. This will correct the myopia of the vertical meridian and also leave a myopia of ^- in the horizontal 7 98 DISEASES AND INJURIES OF THE EYE. meridian to be corrected. The glass then required would be a 20 s. combined with ( O ) 20 c., axis vertical. If, again, we find that the vertical meridian is hypermetropic, say -jig-, and the horizontal meridian -fa hypermetropic, then it is a case of compound hyperopic astigmatism and the glasses required will be +30 s. O +30 c. axis horizontal, which should make all lines perfectly clear. Cases of mixed astigmatism are less common than the other forms and much more difficult to determine, and require a great deal of time and patience in conducting the test, de- mands which are made upon the surgeon with all cases of astigmatism. Astigmatic patients mean well, but their ina- bility to define objects properly has not prepared them to answer correctly, and the result is unsatisfactory, notwith- standing their anxiety to be accurate. Hence repeated exam- inations have to be made, and results compared, before anything satisfactory has been accomplished. Where much difficulty has been experienced the use of atropine, duboisia, or homatropine should be employed to paralyze the accommodation, which becomes a mischievous factor in the examination. The effects of all these mydriatics are unpleasant to the patient from the glare of light which is admitted to the eye by the dilated pupil, and the consequent loss of the accommodation prevents the patient from reading, writing and all near work for some days afterwards. I prefer the hydrobromate of homatropine, two grains to the fluid dram, in these cases, two or three drops producing complete paralysis of the acommodation within an hour. The paralysis lasts only about an hour, the eye fre- quently returning to its normal condition in thirty-six hours. Either this or atropine should be used in all cases of myopic and mixed astigmatism, as oftentimes an apparent myopic astigmatism becomes an hyperopic astigmatism under the influence of the mydriatic or even a case of simple hyperopia or myopia. In cases of mixed astigmatism, one meridian being hyper- opic and the other myopic, the test cards which present a full circle of radiating lines are necessary, and the correction is ASTIGMA T*MANISOMETROPIA. 99 made by two cylindrical glasses which are usually placed at right angles to each other in the defective meridians. For example, if the vertical meridian presents a myopia of T ^ and the horizontal a hyperopia of y 1 ^, then cylindrical glasses are prescribed and the prescription is written 10 c p~ 16 c axis horizontal. If the defective meridians are other than those indicated, then the angles at which the glasses are to be ground are indicated on the optician's blank, which corresponds with the graduation of the trial frames. In regard to the prescription of glasses for astigmatism, if it is simple the full correction may be prescribed at once, and may be worn either for reading or distance, or both, as the individual cases may demand. If compound, the correction of the astigmatism must be fully made, while the use and degree of the glass for myopia or hyperopia must be deter- mined by the rules governing the prescription of such glasses as already described. If the astigmatism is mixed, the full correction is to be given for distance, and probably for near vision also, though the latter is to be decided by the comfort of the patient. If there is much amblyopia the weakest glass, concave or convex, which gives the best vision should be prescribed. In some cases different cylinders will be required for near vision than those for distance. This is more frequently the case in simple astigmatism, and a patient may require a con- vex cylindrical glass for distant, and a concave cylindrical in the same meridian for near vision. When astigmatics become presbyopic the cylindrical correc- tion is to be added to the presbyopic glass. ANISOMETKOPIA. This is a term applied to cases where the refraction of the two eyes is dissimilar. One eye may be hyperopic and the other emmetropic, or one may be emmetropic and the other myopic, in which case the former is used for distant and the latter for near vision. It is not usual to give glasses in these 100 DISEASES AND INJURIES OF THE EYE. cases, as the vision is monocular, and the glasses would cause a difference in the size of the retinal images, and in producing binocular vision cause such disturbance in the accommodative effort that the use of the eyes would become extremely irksome. In some cases the correction may be attempted, but if the glass is not worn comfortably, it should be abandoned. This condition is a frequent cause- of strabismus. CHAPTER VI AFFECTIONS OF THE MUSCLES. ANATOMY f f - JACKSON, M. D. The muscles of the eyeball are of two classes, the intrinsic or internal, those of the iris and ciliary body, and the extrinsic or external, those which prodjice the movements of the eyeball itself. The extrinsic muscles are six in number, four recti and two oblique (Fig. 44). The recti or straight muscles arise from a tendinous ring around the optic foramen and passing forward are inserted into the anterior portion of the sclera at equal distances from each other by expanded tendons. These tendons form a fibrous expansion which encircles the circum- ference of the globe; before insertion into the sclera, they pierce the tunica vaginalis of the globe, dividing it into an anterior portion, Tenon's capsule, and a posterior part, the capsule of Bonnet. The insertions are not all at the same distance from the corneal border, the insertion of the internal rectus being nearest to the sclero-corneal junction, about 5 mm. distant, while the inferior rectus joins the sclera at. 6 mm., the external at 7 mm., and the inferior at 8 mm., from the cornea. These varying distances are to be remembered in making a tenotomy of these muscles. The recti muscles also present variations in their length, the internal being shortest and the external longest. Three of the recti, namely, the superior, inferior and internal, are supplied by the 3rd nerve, while the external derives its nerve supply from the 6th, or 101 102 DISEASES AND INJURIES OF THE EYE. abducens. The blood supply is derived from the muscular branches of the ophthalmic artery, which give off in the tendons the anterior ciliary arteries. The two oblique muscles, the superior and inferior, present a different origin, course and nerve supply; the superior oblique takes origin with the recti muscles, but passes forward to the upper and inner angle of the orbit, there passing over a tendinous pulley, and turns outward and backward, and is inserted by a broad, fan-like tendon into the outer side of the ball behind the equator. It is supplied by the 4th, or trochlear, nerva no. 44. The inferior oblique arises from the superior maxillary bone on the inner floor of the orbit, and passing backward, is inserted on the outer side of the posterior half of the eyeball opposite the insertion of the superior oblique, with the external rectus lying between them. It is supplied by a branch from the 3d nerve. The two oblique muscles serve to suspend the eyeball in the orbit as well as to give it motion. The combined action of the recti muscles results in the re- traction of the eyeball into the orbit, while a similar action of the oblique muscles draws the globe forward. In the complex movements of the eyeball the muscles are grouped together in twos or threes for the movements in various directions, and AFFECTIONS OF THE MUSCLES. 103 each group during action is opposed by a similar group. In the action of the muscles separately, the internal rectus turns the eje directly inward and the external directly outward. The superior and inferior recti turn the eye upward or down- ward, but, owing to the fact that the origins of the muscles are nearer the median line of the head than their insertions, they also turn the eye somewhat inward. In order, then, to turn the eye directly upward or downward the action of the superior or inferior oblique must be added. The superior oblique turns the eye downward and outward and at the same time produces a partial rotation of it from above downward, thus inclining the vertical meridian of the cornea inward. The inferior oblique rolls the eye upward and outward and rotates it from above downward. For looking in intermediate directions, as upward and inward, or downward and inward, a combined action of a group of three muscles is required. This compensatory action of these additional muscles also preserves the proper position of the vertical meridian of the cornea, which would otherwise be drawn too far inward or outward and thus disturb the vision. In the normal action of the muscles, the eye is turned inward by the internal rectus ; outward by the external rectus; upward by the combined action of the superior rectus and inferior oblique; downward by the inferior rectus and superior oblique. In the motion of the eye diagonally upward and inward the rectus superior acts in combination with the rectus internus, and is further controlled by the inferior oblique in directing the eye upward and outward. The rectus superior and the rectus externus are assisted by the inferior oblique, which limits the action of the rectus superior in looking downward and inward; the rectus inferior and the rectus externus by the superior oblique, which controls the full action of the rectus inferior. The movement downward and outward is accomplished by the rectus inferior together with the rectus externus and superior oblique, the latter limiting the action of the rectus inferior. From the central line the emmetropic eye may move inward 45 degrees; outward 50 degrees; upward 35 degrees; and 104 DISEASES AND INJURIES OF THE EYE. downward 60 degrees. These movements are restricted in myopic eyes by the increase in the antero-posterior axis. In binocular vision there is an associated movement of both eyes, the movement inward of one being accompanied by an out- ward movement of the other, the different sets of muscles acting in this way being termed conjugate, or yoked muscles. In the accommodative or converging movements of the eyes, similar groups of muscles act in harmony. A disturbance of the harmony of the action of the muscles at once causes a deviation from the line of vision, and may result from an excess or loss of power of one or more muscles. This is termed the primary deviation, and produces diplopia and squint. If one of the conjugate muscles becomes weakened or paralyzed, a greater effort becomes necessary to enable it to attempt the motion of the eye. This effect, being transmitted to its conjugate muscle, produces there another action and consequent greater movement. This change in the direction of the other eye constitutes the secondary deviation. The muscular adjustments must be exact, and the motor influences transmitted just sufficient to produce that perfect harmony of action necessary to direct the yellow spot of the retina of each eye upon the object, and thus produce binoc- ular vision. If the foveae are not focused upon the object, or if the images of the object do not fall upon corresponding portions of the two retinae, then double vision or diplopia occurs. In the normal eye, when the gaze is fixed upon an object at a distance, the visual axes appear parallel. In myopic eyes the axes may converge slightly, owing to the foveae lying nearer to the axis of the eyeball, an apparent turning inward of the eyes. In hypermetropia the axes of the eyes frequently diverge slightly; this is not, however, divergent strabismus, but is due to the fact that the yellow spot usually lies farther from the axis of the eyeball in hypermetropic than in emmetropic or myopic persons, hence, when the optic axis of the eye is directed towards distant objects, the axis of the eyeball looks outward more than in the normal eye, giving rise to the appearance of divergent squint. DIPLOPIA. 105 Fl DIPLOPIA. Diplopia, or double vision, arises when the visual axes are not both directed upon the object under examination, and is almost always caused by a deviation of the eyes or squint, but this may appear so slight as to escape attention in many cases. Double vision is sometimes monocular, depending upon irregularities of the cornea, lens, or some disturbance of the retinal elements. It is, however, almost always binocular, disappearing when on'e eye is covered. Binocular diplopia is of two kinds, homonymous or direct and hieronymous or crossed. Direct diplopia will be understood by an examination of Fig. 45, which shows the position of the double images in convergent squint. Here M represents the macula lutea, or yellow spot of each eye, O the object looked at, and V M the visual axis of the squinting eye. The image of the object O will fall upon the yellow spot M in the left eye, and the object is seen in its true position and forms a true image. The visual axis of the right eye deviates in- ward and the image falls upon a portion of the retina to the inner side of the yellow spot, and the object will appear to be at F J, because the part of the retina which now receives the image has been accustomed to receive objects from this direction when the eye was in its normal position, and hence mentally projects the image in that direction. Thus two images become visible, one in its real position at O and another to the right of it at F J, the latter being the FIG. 45. 106 DISEASES AND INJURIES OF THE EYE. false image. If the left eye is turned in and the right eye remains in the normal position, then the false image will be to the left of the true image. In these cases the greater the deviation of the eye the greater the squint, and the wider apart are the two images. The false image, falling upon an eccentric portion of the retina, is not usually as distinct as the true image, which is formed upon the yellow spot; the greater the squint the less distinct will the false image be, as it is then formed still further from the central portion of the retina. In the second form, or crossed diplopia, the images cross each other as shown in Fig. 46. Here, a divergent squint is present, the left eye being fixed upon the object at O, and the f right eye deviating out- P4\ ward from its fellow. The object at O is perceived in its proper position by the left eye, and a true image is formed upon the macula lutea at M. The right eye, however, being turned outward, the macula is di- rected toward V, and the image of the object at O falls upon a portion of the retina to the outer side o the macula, and is ment- ally projected to the left of O at F I, and the false image is thus seen to the left of the true image, and they appear crossed. If the squinting eye is turned upward, the image falls upon the retina above the macula and appears below the true image. If the eye squints downward, then the false image is projected above the true image as seen by the other eye. The false image formed in cases of squint, if sufficiently well defined, will FIO. 46. DIPLOPIA PARALYSIS OF OCULAR MUSCLES. 107 be perceived, and the images received by the two eyes, being superimposed in the sensorium, will cause a con- fusion of the vision, and vertigo, nausea or pain results. In many cases, particularly if the deviation which causes the diplopia is great, or exists for a long time, only one image is regarded, the perception of the other being neglected or suppressed; the suppressed image ahvays being that of the squinting eye. To detect the presence and position of the double images in diplopia, the patient should be taken into a dark room, the head fixed or held in one position without moving, and a colored glass, blue or red, placed before one eye. A lighted candle is then held eight or ten feet distant and moved to the right, left, above, below, and other inter- mediate portions of the field, and the patient asked which is the colored flame. The position of the images, as described by the patient, are then noted upon a slip of paper, but if the deviation is very great, and, particularly, if the action of the internal rectus is poor, the false image becomes indistinct, and difficulty is experienced in getting proper replies from the patient; in such case it is better to place the colored glass before the sound eye. The greater the distance of the candle and the farther it is moved in the direction of the affected muscle, the more widely separated the images become. For all practical purposes a roll of white paper one foot long, held perpendicularly ten feet distant from the patient in a lighted room, will suffice; one eye should be covered with a red glass and the height, lateral separation and apparent distances recorded as before. PARALYSIS OF THE OCULAK MUSCLES. In rare cases all of the muscles may be paralyzed, the third, fourth and sixth nerves all participating. In the majority of cases single muscles, or those supplied by one nerve, are alone affected. In many cases the condition may be only one of paresis, which may follow or precede the paralysis. The affection is seldom symmetrical, and in rare cases where it 108 DISEASES AND INJURIES OF THE EYE. does occur, the cause is always intra-cranial or spinal. Where it is monolateral the lesion may be either local or central. In most of the cases of uncomplicated paralysis of the ocular muscles, there is nothing in the state, either of the eye or orbit, to enable one to locate the cause either in the orbit or cranium. The probable location of the lesion, in either case, may be determined by noting whether all the muscles supplied l>y the third nerve are affected or only one of them, or whether the fourth or sixth nerves are alone affected, while bearing in mind their origin and course in the brain and orbit. CAUSES. Rheumatism, syphilis, localized periostitis, inflam- mation of the nerve sheath, injuries, basilar meningitis, tumors of any kind, hemorrhage and central nerve degenerations, are all active causes in the production of paralysis of the ocular muscles. SYMPTOMS. Loss of mobility in the direction of the para- lyzed muscle is, objectively, the most^prominent symptom. Jf the patient is directed to look at an object, as the finger, held before the eye, and follow its movements without changing the position of the head, the affected eye is found to fail in its movement in the direction of the affected muscle in proportion to its weakness. Subjectively, diplopia is complained of, and this is often present before the loss of motion can be detected. The position of the images, whether homonym ous or crossed, and above or below, will give a clue to the muscles affected. With the diplopia there is often false projection of the field of "vision, the image falling upon an eccentric portion of the retina, the patient is unable to determine the exact distance, and hence experiences difficulty in walking, or reaching for objects, and this not infrequently results in nausea and vertigo, or other cerebral symptoms. The head is usually inclined in the direction of the affected muscle so as to lessen the diplopia "by favoring it, or the eye is closed to obviate double images. Undue prominence of the eye occurs in paralysis of all the recti, and is accompanied by a drooping of the lid (ptosis). Squint is always a symptom of paralysis, where the affection lias existed for some time, and is due to the contraction of the DIAGNOSIS OF PARALYTIC AFFECTIONS. 109 opposing muscle, the eye being permanently fixed in the direction opposite to the paralyzed muscle; and when this, occurs, the vision of the affected eye rapidly deteriorates from the suppression of the image, and amblyopia from non-use results. In paralytic squint, if the hand is placed over the sound eye in such a manner that its movements may be observed, while the affected eye is directed upon the object held before it and moved in the direction of the paralyzed muscle, the eye will attempt to follow it. The effort thus made is transmitted to tho conjugate muscle of the other eye, and a motion of the sound eye will occur, which will carry it so far as to produce a squint which is greater than that of the affected eye ; this is termed the secondary deviation or squint. In paralytic squint this secondary deviation is always greater than the primary deviation of the affected eye. DIAGNOSIS OF PAEALTTIO AFFECTIONS OF DIFFERENT MUSCLES. EECTUS INTERNUS. "While the isolated paralysis of the branches of the motor oculi are not common, the branch sup- plying the internal rectus is more frequently affected than the others. The eye cannot be turned inward, and divergent squint may result. Diplopia appears, and the images are crossed vertically and on the same level, and become wider apart; or the false image disappears when the object is carried to the opposite side of the affected muscle. The patient turna the head toward the direction opposite to the paralyzed muscle to overcome the diplopia as far as possible. RECTUS SUPERIOR. If the nerve supply of the superior rectus is deficient the patient finds difficulty in ascending stairs, as the false image is projected above the true image, diverges from it at the top and is slightly crossed, and a down- ward squint results. As the superior division of the third nerve also supplies the levator palpebrae, ptosis is almost always a complication. To correct the diplopia the head is directed upward and backward. RECTUS INFERIOR. If the rectus inferior is paralyzed, the 110 DISEASES AND INJURIES OF THE EYE. eye cannot be turned downward, although there is an oscillating movement in that direction resulting from the action of the superior oblique. Tho diplopia is somewhat crossed, the false image is below, but converges at the top and appears closer to the eye than the true image. Difficulty is experienced in going down stairs or in walking, and to overcome the defect the head is carried forward and downward. If squint results the eye is turned upward. INFERIOR OBLIQUE. The eye cannot be rotated upward and outward, and when an attempt is made to look upward the superior rectus carries the eye upward and inward. It rarely, if ever, occurs without some of the other muscles being involved. The double images are crossed and appear one above the other and the false image is inclined towards the other at the bottom. If the eye is moved inward the difference in the height increases, and when turned outward, the inclina- tion of the images becomes more marked. PARALYSIS OF THE THIRD NERVE. In complete paralysis of the third nerve, the uppei lid droops over the ball (ptosis) and the eye is turned outward and cannot move in any direction except partly downward. The pupil is dilated, the accommo- dation paralyzed and the eyeball is more prominent from the loss of the normal tension of the recti. When all the muscles supplied by the third nerve are affected, the lesion exists either at the apex of the orbit or in the cranium. If only one or two of these branches are paralyzed the cause is situated in the orbit SUPERIOR OBLIQUE. Here there is homonymous diplopia in the lower half of the visual field. The eye lags when the vision is directed downward, the ball moving downward and inward. The double images separate more widely and the upper ends are inclined toward each other. The patient finds difficulty in descending stairs, and endeavors to correct it by carrying the head forward and to the opposite side of the eye affected. EXTERNAL RECTUS. The paralysis of the abducens is more frequent than the other forms, and causes, as it is complete or PARALYTIC AFFECTIONS TREATMENT. HI partial, more or less inability to turn the eye beyond the middle line. The diplopia is homonymous and is more marked when the object is moved to the affected side, lessening and disappearing as the eye is turned inward. The images are parallel, perpendicular and on the same level, but when the object is moved diagonally upward and outward the false image is lower than the true, diverging slightly at the top, and when moved downward is higher, inclining slightly at the top, and appears nearer to the patient, while convergent squint generally results. The patient endeavors to overcome the faulty action of the muscle by turning the head in the oppo- site direction to the affected eye. TREATMENT. When the paralysis is effected by rheumatic or syphilitic causes the prognosis is usually very favorable, but when arising from intra-cranial or spinal disease, recovery is less likely to occur. If the recovery is not complete, paralytic squint and diplopia usually remain. The treatment must be addressed to the probable cause, and to discover this requires a very careful inquiry into the history, symptoms and condition of the patient. The ophthalmoscope may prove an aid by revealing the presence of an optic neuritis dependent upon intra-cranial or orbital specific lesion. Faradaism and galvanism may prove beneficial and in some cases effect a cure alone. The galvanic current appears more useful than the faradic, and the application should last but a minute, and be made daily. A small bulb electrode, covered with wet chamois skin, may be applied to the conjunctiva directly over the insertion of the muscle, or in the same posi- tion upon the closed eyelid. The other pole may be applied to the occiput or to the mastoid. Usually, the negative elec- trode should be applied to the eye, but some cases will be more benefitted by the reverse current. The strength of the current must not be sufficient to cause vertigo, nor the electrodes sud- denly lifted after having been applied to the head. A small 112 DISEASES AND INJURIES OF THE EYE. percentage of cases will be improved by the use of the f aradic or galvanic current applied to the angle of the jaw and to the supra-orbital region and side of the nose ; the result accom- plished being due to the reflex irritation through the fifth nerve. Prisms set in spectacle frames may correct the double vision, but practically prove of little service, as the prism can only relieve a certain amount of the diplopia, which varies with the direction of the vision. To determine the degree of the prism required, the patient is directed to regard a lighted candle or gas-jet, ten or twelve feet distant, when he will see two images of the light. The weakest prism, base in or out according to the muscle affected, which will unite the images will be the one required, but if it is over eight or ten degrees, then the prismatic glasses become too bungling for comfortable wear and the effect may be divided between the two eyes, and the affected eye given slightly more than one-half the whole degree. After a week or two it may be found that weaker prisms will enable him to fix the images, and the glasses should be accordingly changed until very weak prisms, or none, are required. In addition to the aids already recommended, medical treatment will prove useful in many cases when the remedies are selected according to the cause and symptoms. Aconite. This remedy suits those cases of partial paralysis arising from exposure to cold winds or draughts. Argentum nitricum. Cases of paralysis of the internal rectus have been relieved by this remedy. Arnica. Commonly indicated in those cases of temporary paralysis resulting from injury. Causticum. Paralysis of the muscles resulting from ex- posure to cold, particularly of the external rectus, with some involvment of the third nerve, and may be useful in a general peripheral paralysis of any of the ocular muscles. Chelidonium. Paralysis of the right external rectus. Cuprum aceticum. Paresis or paralysis of the external rectus.. MUSCULAR ASTHENOP1A. 113 Euphrasia. Paralysis of the branches of the third nerve arising from exposure to cold or wet, the other symptoms of Euphrasia being present. Oelsemium. Extremely valuable in those cases following diphtheria, the action upon the external rectus being more marked. Kali iodatum. Particularly indicated in paralysis of the muscles arising from syphilitic causes, more commonly the paralysis of the rectus externus. Mercurius iod. Paralysis of the third nerve and its branches in cases arising from syphilis. Nux vomica. Paralysis or paresis of the ocular muscles, accompanying gastric disturbances, and if aggravated by tobacco or stimulants. Phosphorus. Paralysis of the muscles arising from ex- cesses, and accompanied by general loss of muscular tone. Rlius iox. Paralysis of the muscles arising from rheuma- tism, exposure to cold and wet. Senega. This remedy has been reported as curing loss of power of the left superior rectus and other branches of the occulo-motorius, and is beneficial in paralysis of the superior oblique. Other remedies, as Aurum, Hyoscyamus, Conium, Morph. and Sulphur may be used with advantage. Paralytic squint, arising as it does from the secondary con- traction of the opposing muscle, requires operative measures for its relief when the recovery of the paralyzed muscle is hopeless. For its correction, tenotomy of the contracting muscle should be made .and at the same time the insertion of the paralyzed muscle advanced, as will be described for certain cases of strabismus. MUSCULAR ASTHENOPIA Paresis of the muscles, muscular weakness or insuffi- ciency, is not usually great enough to produce any deviation of the eyes or squint, but manifests itself in pain or fatigue 8 114 DISEASES AND INJURIES OF THE EYE. after use of the muscles involved. The muscles most com- monly affected are the internal and external recti. In rare cases the insufficiency may be traced to the superior oblique, and to the superior and inferior recti. CAUSES. Refractive errors are usually the productive causes of muscular asthenopia; myopia and astigmatism producing weakness of the internal rectus, and hypermetropia of the e external rectus. The other causes productive of muscular asthenopia in either ernrnetropia or ametropia, are, fatigue of the eyes from over-work on fine objects, as in flower or china painting, embroidery, etc.; general neurasthenia, when the muscular insufficiency may accompany or follow the general condition; convalescence after continued fevers or the exan- themata, particularly reading in a prone position; uterine diseases; chorea; excesses of any kind; derangement of the digestive organs; insufficient food; or, the muscular weakness may be congenital. SYMPTOMS. The symptoms are those of fatigue from use of the eye. There is pain which may be referred to the eye- ball, forehead, temple, or vertex, producing what may well be termed asthenopic headaches. The pain is temporarily relieved by pressure upon the closed eyes and momentary rest Dizziness and nausea are not infrequent accompani- ments of the condition. After reading for a time the letters may appear to dance or swim before the eyes, producing a blur, which is similar to that occurring in weakness of the accommodation. "^ KjJv^. Insufficiency of the internal recti is more common than the other forms, and is produced by the lighter degrees of myopia, the strain upon the internal recti being relieved by the divergence of the eyes in the higher degrees. It appears, however, with almost equal frequency in eniinetropic, rarely in hypermetropic eyes, from the causes already enumerated. Insufficiency of the external recti occurs with much less frequency, and hypermetropia forms the most common cause. The ciliary muscle not infrequently participates in the weak- ness, when the case becomes complicated with accommodative asthenopia or ciliary spasm. 7 MUSCULAR ASTHENOPIA TREATMENT. 115 DIAGNOSIS. The diagnosis is readily made by directing the patient to look at the finger or pencil, held eight or ten inches from the eye in the median line. One eye is then covered by a card in such a manner as to shut out the eye from the object of fixation, but at the same time to enable the observer to see if it deviates outward. A more delicate test is that of Von Graefe where a prism of eight or ten degrees is placed with the base up or down before the eye, and the patient directed to look at a black dot on a vertical line, as in Fig. 47, held at the usual reading distance. If the relative strength of the muscles is normal, two dots will be seen on the same line, but if two lines appear with a dot upon each, the lateral sepa- ration of the lines measures the insufficiency, or it may be measured more accurately by the prism, with the base turned inward or outward, which is sufficient to fuse the images of the two lines; placing a colored glass before one eye will determine whether the images thus formed are homonymous, as in affections of the internal recti, or crossed, as with insufficiency of the external recti. TREATMENT. The treatment consists principally in the correction of the refractive error, the methodical exercise of the eyes for increasing periods daily, and the use of such remedies as have an action upon the ocular muscles. This is usually all that is needed to complete the cure; where myopia is the cause, the glasses may be slightly decentred, or prisms with the base inward combined, or weaker glasses than those required for distant vision prescribed. If hypermetropia is the active cause, the glasses to correct the refraction may be required to be worn constantly, or combined with prisms, or decentred, FIG. 47. or set nearer together. Slight degrees of astigmatism which are not sufficient to impair the visual acuity may be required to be corrected by glasses which are to be worn constantly. The galvanic or f aradic current, often improves the muscular tone and may be applied for two or three minutes daily, one pole over the closed eyelids and the other 116 DISEASES AND INJURIES OF THE EYE. upon the temple or nape of the neck. Treatment which tends- to improve the general vigor of the patient and remove any constitutional derangement, improve digestion, and increase the general muscular tone, is indicated. For the methodical exercise of the eyes, the patient is to read in the morning, after breakfast, for two, three or five minutes the first day, and the length of the reading period increased by one or two minutes a day until half an hour, or an hour is reached; no additional increase is now made for several days, then another sitting may be begun for increasing periods. The sittings should always stop short of fatigue, and it may be necessary to return to a less number of minutes until the first point of fatigue is again passed comfortably. The gymnastic exercise of the muscles by the use of prisms of varying degrees, the bases of which are turned alternately in or out, may be useful in a few cases, but the results are not as favorable as they would seem likely to be. The patient takes the prisms of five, ten, or fifteen degrees, placing the bases in or out according as the weakness is of the internal or external recti muscles, and tries to fuse the images of a gas- jet fifteen or twenty feet distant. Still stronger prisms are used the next day, and the exercise continued until a satis- factory increase in the power of the muscle has taken place. I have known patients by daily exercise to finally overcome prisms amounting to sixty degrees in adduction without improvement in the symptoms of asthenopia, although there was a constantly increasing improvement in the adductive power of the internal recti. Much relief is experienced in asthenopia by the prescription of the proper medicinal remedy according to the following indications: Aconite. Asthenopia from over-use of the eyes ; lids spas- modically closed with a heavy feeling in them. Hot and dry feeling of the eyes after use, relief from cold applications. Agaricus. Twitching of the lids, jerking or sensation of jerking in the eyeballs. Argentum nitricum. Weakness of the internal recti, together with weakness of the accommodation dependent upon hyperopia; blurring and dancing of the letters. ASTHENOPIA REMEDIES. 117 Duboisia. External recti weak, with weakness of the accommodation, and hot dry feeling of eyes from reading. Calcarea carb. Pains after using the eyes; pains referred usually to the lids; sticking pains while using the eyes for close work ; eyes feel better from applications of hot water. Gelsemium. Asthenopia with weakness of the external recti, often associated with spasmodic condition of the internal recti Jaborandi. Asthenopia, with symptoms which are really dependent upon irritability of the ciliary muscle, and in those cases of muscular asthenopia arising from reflex irritation o the uterus. Kalmia lat. The muscles, either the internal or external recti feel stiff, eyeballs feel stiff. Lilium iigrinum. Burning, smarting, and heat in the eyes; relief in the open air. Mercurialis per en. Dryness of the eyes and heaviness of the lids; mist before the eyes; burning pain in the eyes and upon reading. Natrum muriaticum. More frequently indicated than other remedies. Refractive error may or may not be present. Par- ticularly suits those cases caused by over-use, or too close application for near objects; the vision blurs and the letters run together upon using the eyes for reading. Weakness of the internal recti is oftentimes very marked ; the muscles feel stiff and drawn, and ache on using the eyes in any direction ; pain in the eyes on looking down ; suits some cases of asthenopia, with headache, burning, smarting, itching and heat with a "variety of other sensations. Phosphorus. Deficiency of sight, with pain and stiffness in the eyeball; light aggravates so the patient is better in the twilight; symptoms of retinal irritation accompany. Physosiigma. Weakness of internal recti. Fatigue and twitching of the lids from reading. Rhododendron. Insufficiency of the internal recti muscles with darting pains through the eyes and head, usually worse before a storm. Sepia. Some cases of muscular insufficiency arising from 118 DISEASES AND INJURIES OF THE EYE. reflex irritation of the uterus ; smarting of the eyes ; aggravation of the symptoms in the morning and evening. Spigelia. If accompanied by sharp sticking pains in the eye and around it, extending back into the head. In addition to these many other remedies may be indicated by their constitutional symptoms, as Crocus, Cimicif., Ignatia, Ledum, Lith. carb, Macrotin, Nux vomica, Phos. acid, Pulsa- tilla, Santonine and Sulphur. STKABISMUS. Strabismus, or squint arising from paralysis of the ocular muscles has already been considered, but there is another form of squint which is dependent upor. the contraction of certain of the ocular muscles, and is termed concomitant strabismus, or simple squint. In the paralytic variety there is loss of mobility of the eye in some directions, but with concomitant squint, the eyes when tested separately, are freely movable in any direction, although there is an inability to fix both eyes upon an object at the same time. Of strabismus we have four varieties, convergent or internal, divergent or external, sursumvergent or upward, and deorsum- vergent or downward. CONVERGENT STRABISMUS. The most common and readily treated is convergent strabis- mus, which depends upon a shortening of the internal recti muscles and generally commences in infancy. The visual axes cross in front of the object, and there is diplopia in the begin- ning, but the child soon learns to suppress one image, and from this suppression of the image the squinting eye soon becomes amblyopic from want of use. In most cases only one eye is used for vision and the other is turned inward towards the nose. In some cases one eye is used for a time and then the other; this constitutes alternate squint and in this case the vision is usually retained in both eyes. If the squint is not constant, but appears only at times, it is termed periodic CONVERGENT STRABISMUS. 119 squint, but, after an interval of weeks or months, it becomes permanent. The amount of squint is generally greatest during near vision, and often disappears entirely when distant objects are looked at. CAUSES. The causes are variously stated by the laity as arising from convulsions, whooping cough, measles, scarlatina, fright, falls, and imitation of other squinting children. Some of these causes are undoubtedly the excitants in some cases, by producing a weakened condition, or paralysis of the exter- nal recti, which results in a preponderance of power of the internal recti. The common cause of convergent strabismus is, however, due to hypermetropia. When we look at near objects we do two things, we converge the optic axes by using the internal recti, and then accommodate for a near point, conver- gence and accommodation being physiologically connected. In hypermetropia accommodation is necessary for distant objects, and convergence, or a tendency to convergence, results. If binocular vision exists, the hypermetrope endeavors to form a single image, and consequently gives up the attempt to see at a distance, which would require the full exercise of the accommodation, and result in a convergence of the axes and in the production of diplopia. If the vision is more defective in one eye, the image produced upon the retina being less distinct than the other is disregarded, and convergence in accord with the full amount of accommodation is allowed, and, while the better eye is directed upon the object, the other is strongly turned inward. In these cases the internal recti become, from constant exercise, more highly developed than the external, and, having once overcome the latter, permanent contraction results. Convergent strabismus appears during the first years following infancy, the majority of cases occur- ring between two and five years of age, at the time when the child is just beginning to use the eyes for observation of its toys, picture books, or make its first attempts at reading. It may be only occasionally observed; later, it becomes alter- nating, and finally permanent. The vision of the excluded or squinting eye rapidly 120 DISEASES AND INJURIES OF THE EYE. deteriorates from two causes; that most commonly given is amblyopia, or poor vision, from want of proper exercise of the region of the yellow spot at a time when the eye is still developing ; secondly, compression of the eyeball by the tension of the rectus externus, which is put upon the stretch by the con- traction of the internus. The necessity for early treatment in these cases arises, not for relief of the deformity, but to pre- serve the eyesight DIAGNOSIS. The diagnosis as a usual thing is easily made, the squinting eye not being directed towards an object held before the patient ; but in some cases the deviation is not very great, and there may be some doubt as to which is the affected eye. In such cases the patient should be directed to look at the top of the finger of the surgeon, while each eye is alter- nately shaded with a card or the hand. The squinting eye moves when the other is covered, since the patient now directs it to the object; the other eye does not move when the squint- ing eye is covered. The differentiation between a concomitant squint, and a paretic or paralytic squint arising from affections of the exter- nal rectus, is determined by the primary and secondary devia- tions, or squint, being equal in the former, while in the latter, if the sound eye is being watched behind the card while the patient regards the near object, the motion of the sound eye inward is much greater, and in addition there will be a loss of movement of the eye in the direction outward. The degree of squint is measured by noting the distance between a vertical line drawn through the centre of the pupil and the lachrymal punctum of the lower lid. An ivory scale or strabismometer (Fig. 48) graded in lines or half lines or millimetres may also be used. This is placed against the lower lid of the squinting eye and the point of the vertical meridian of the cornea is noted; the other eye is now covered and the deviation noted in the same way, and the difference between the measurements thus made gives the amount of squint in lines or millimetres. The vision of each eye should be tested, and together with the amount of refractive error recorded, as CONVERGENT STRABISMUS. 121 well as the amount of squint, and the relative strength of the external recti muscles will have a bearing upon the operative treatment in some cases. TREATMENT. While convergent strabismus shows a ten- dency to lessen as age advances, yet the importance of early operative treatment cannot be too strongly insisted upon, as the sight is often sacrificed from the delay occasioned by the expectation of improvement with age. If the case applies for treatment before the squint becomes fixed, the use of atropine to paralyze the accommodation of the sound eye, or both eyes, by preventing near vision, lessens the tendency to convergence. If the eye has become permanently fixed and an early operation is not desired, the use of a bandage over the sound eye for stated periods daily will retain and increase the visual power of the affected eye; still better is the use of atropine in the sound eye, which will compel the squinting eye to again participate in the act of vision. The greatest objection to the use of atropine is the photophobia which arises from the dilatation of the pupil. These measures may prevent temporarily the increase of the squint and the advancing amblyopia, but the most effective results will be obtained by the use of proper convex glasses as deter- mined by the ophthalmoscope, when the use of them is deemed practical in young children. In many cases of squint the use of certain homoeopathic rem- edies in the early stages has relieved the tendency to perma- nent strabismus. The most useful remedies are Belladonna, Aconite, Gelsemium, Hyoscyamus and Jaborandi. The remote causes, however, more frequently determine the remedy; as squint arising during dentition may demand Chamomilla, Belladonna, or Hyoscyamus; while if dependent upon some irritation of the digestive tract, Santonine, Cyclamen, Mer- curius, Spigelia or Sulphur may be beneficial. Convulsions or whooping cough may indicate Belladonna, FIG. 48. 122 DISEASES AND INJURIES OF THE EYE. Hyoscyamus, Cuprum, Agaricus, Stramonium and Phosphorus. Some cases following measles and scarlatina I have relieved by the use of Belladonna, Cyclamen, and Phos. Acid ; but care must be taken to improve the nutrition, as such cases do not present the squint except when the stomach is empty, or during the early stages of a meal. Benefit is often derived by increasing the number of meals during the day temporarily, or prescribing a table-spoonful of some native wine just before meals. If the methods already stated do not improve the condition then tenotomy of the internal rectus becomes necessary, and its early performance should be insisted upon. In uncom- plicated cases, the prognosis is very favorable. The operation consists in the division of the internal rectus at its tendinous insertion into the sclerotic, and its subsequent re-attachment farther back to allow the eye to resume its normal position. The time for the performance of the tenotomy will depend upon the permanency of the squint and the condition of the vision of the squinting eye. If the vision is poor the child may be operated upon at two years of age, but usually better results are obtained after six years of age, the effort having been made to maintain vision in the poor eye by methodical exercise. If the squint is periodic, or alternating, there is no danger of the sight diminishing unless the squint becomes permanent, and the operation may be delayed until then. Binocular vision is more frequently obtained where the operation is made early in life, but probably not over one third of the cases operated upon regain binocular vision, although parallelism of the eyes results. The amount of convergence must be the guide as to whether one or both internal recti require division, the fact that only one eye squints having nothing to do with making the decision. Both eyes are to be operated upon whenever the degree of squint amounts to over three lines, or 6 mm. If it is desirable, the operation may be made to correct one half of the squint, and after two or three weeks a slighter operation may be made upon the squinting eye. Equally good results are obtained when both OPERATION FOR CONVERGENT SQUINT. 123 eyes are operated upon at the same time. In all cases where the squint is less than three lines, the tenotomy should be made upon the squinting eye alone. After the eyes are again parallel as a result of the opera- tion the use of glasses to correct the refraction may be neces- sary in order to prevent a return of the squint and maintain, binocular vision. OPERATION FOE CONVERGENT SQUINT. For the operation a speculum, a pair of strabismus or fixa- tion forceps (Fig. 49), a pair of curved scissors (Fig, 50) and FIGS. 49 & 50. two strabismus hooks (Fig. 51) are necessary. The patient is to be etherized in a recumbent position, and the operator stands behind the head, or at the side, as desired. Adults, usually undergo the operation without the use of anaesthetics, but for children ether or chloroform should be used in accord- ance with the judgment of the operator. The speculum is introduced and holds the lids apart. If the eyeball rolls FIG. 51. upward under the influence of the anaesthetic, the conjunctiva below the cornea is caught by the forceps and the eye rotated downward into position; the conjunctiva and subconjunctival tissues over the insertion of the internal rectus muscle are now seized by the strabismus forceps and cut through with the DISEASES AND INJURIES OF THE EYE. scissors, a small opening being made either vertically or hori- zontally, and the strabismus hook introduced into the opening and passed beneath the tendon, which is then raised upon the Jiook and carefully divided by several snips with the scissors <3lose to the sclerotic, as in Fig. 52. The hook is again intro- duced to ascertain whether all of the fibres of the tendon have been divided, care being taken not to produce much separa- tion of Tenon's capsule by sweeping the hook too far round. There is usually a great deal of blood effused into the subcon- junctival tissue following the division of the tendon. The more extensive the division of Tenon's capsule, the greater "will be the effect of the operation, and much judgment and experience is necessary to decide how much will be required in any given case. The effect of the operation can be lessened by the introduction of a suture. To do this a curved eye- needle after being threaded with fine black silk is placed in the needle-holder (Fig, 53), and the conjunctiva at the mar- gin of the cornea held by a pair of forceps while the needle is passed through, and then through the conjunctiva over the muscle, and the conjunctival wound brought together. This should be done before the patient recovers, and if not needed, OPERATION FOR CONVERGENT SQUINT. 125 is easily removed afterwards. The patient is roused from the anaesthetic and made to look at the finger, held a foot distant before the eye, and the position of the eyes noted. If the amount of the operation has been well gauged the eyes will fix properly upon the object. The eye should then be directed towards the divided muscle, and if squinting results, or the eye moves inward, some fibres of the tendon have escaped cutting and the hook must be introduced and the fibres caught up and divided. As soon as the effect of the ansesthetic has FIG - 53 - vision is good and the action of the muscles correct, the patient should be able to fix the eyes upon an object held eight or ten inches before him. If the eye, after a few moments, diverges, then the operation has been excessive and a suture should be intro- duced to lessen the effect. If the vision is poor, or the muscles weak, a convergence at twelve inches is sufficient. After the operation the eye should be bathed with cold water or a decoction of calendula flowers, no bandage being worn except from the clinic or office to the patient's home. Diplopia is complained of in some cases on the second day, but usually disappears as the muscle regains power, and is not an unfavorable symptom. In some cases there is often a slight divergence for a few days or a week. The improvement in the vision of the squinting eye is, oftentimes, almost immediate, the loss of function here being dependent upon the tension of the recti muscles. If the external rectus is weak, and the patient consents to have only one eye operated upon, a strong suture may be introduced through a large fold of the conjunctiva, which is picked up by the forceps between the outer margin of the cornea and the external canthus, the two ends of the sutures armed with needles being carried through the skin of the external canthus, one above and one below, so that they are separated one-eighth of an inch, and then tied. The eye is 126 DISEASES AND INJURIES OF THE EYE. thus held in proper position until the tendon becomes re-at- tached, which results after forty-eight hours, when the suture is removed. Severe reaction sometimes follows the introduc- tion of these counter-sutures, which can readily be controlled by the use of cold compresses. Other operations for tenotomy are used by various surgeons according to individual ideas; when a slight correction only is necessary it may be done by making a short horizontal incision in the conjunctiva and subconjunctival tissue at the lower border of the insertion of the tendon, passing in the hook and dividing the tendon as before; the hemorrhage is very slight and there is less tendency to sinking of the caruncle. The eyeball becomes slightly more prominent after tenotomy and there is a corres- ponding sinking of the caruncle. In some cases a mass of granulations are developed about the stump of the tendon, which becomes pedunculated as the conjunctiva heals around it, and, either drops off spontaneously, or may be clipped with the scissors. If the operation has been excessive, a divergent squint will result, and require the advancement of the inser- tion of the opposite muscle. DIVERGENT STRABISMUS. This condition is much less frequent than the one already described, and is produced by the increased strength of the external recti over the internal. CAUSES. In myopia, which causes the larger number of frr- freely anastomose with each other and expand into lenticular shaped spaces or lacunae; in the latter are found the true corneal corpuscles, which consist of masses of protoplasm containing a large nucleus and branch- ing processes which partially fill the lacunae and extend some- what out into the canaliculi. Other varieties of cells appear in the cornea, some which seem to be portions of the fixed DISEASES OF THE CORNEA. '237 cells, and others wandering or migratory cells similar to white blood corpuscles, and at the margin of the cornea are found pigment cells identical with those of the sclera. This system of canals carries the nutritive fluid from the periphery towards the centre of the cornea, the corneal tissue being formed from the migratory and fixed cells. The corneal tissue with its canals passes over into the sclera. The true corneal tissue is limited internally by the posterior elastic membrane, which is thicker than the anterior elastic membrane, and more separable from the overlying tissue than the latter. Upon this membrane rests a single layer of epithelial cells held together by cement substance. The posterior surface of the cornea extends further back than the anterior so that it ia slightly overlapped by the sclera. The membrane of Descemet is a firm, structureless, but very elastic membrane, which, at its circumference, breaks up into- trabeculse or fibres which are partly continued into the front of the iris forming the ligamentum pectinatum iridis and partly into the anterior portion of the choroid and sclera. That portion forming the ligamentum pectinatum is covered with endothelial cells. These cells, however, do not stretch across the intervals between the processes, but leave spaces of communication between the anterior chamber at this part (the angle of the iris), with the canal of Schlemm. In a state of health the cornea is not provided with blood- vessels except at the circumference, where they form very fine capillary loops and accompany the nerves. No lymphatic Vessels are discoverable and the lymph is undoubtedly carried on by the canal system of the cornea. The nerves are very numerous and are derived from the ciliary, which enter the fore part of the sclerotic, and are from forty to forty-five in number. They become transparent soon after entering the cornea and form several plexuses, through its structure and immediately beneath the epithelium, from which branches pass forward to form a terminal plexus amongst the epithelial cells. 238 DISEASES AND INJURIES OF THE EYE. DISEASES OF THE CORNEA. The cornea may be the seat of inflammatory action which results in infiltration of its structure, changes in its tissue, or, its destruction in whole or in part. These pathological changes may be superficial or deep, and consist chiefly of an infiltra- tion of the cornea with serum, or white blood corpuscles, from the marginal vessels; and an increase of its cells due to proliferation, as in the diffuse form of keratitis ; or, if superficial and circumscribed, it may be a phlyctenular inflammation. If these cells are aggregated in a circumscribed portion so that the nutrition of the underlying layers is interfered with, loss of substance occurs and a corneal ulcer results, or, if the surrounding tissue does not give way, an abscess is formed, and if the infiltration becomes so great that the nourishment cannot be carried on through its natural channels, the whole cornea may be destroyed by the suppurative process. In the process of repair the new tissue is not always as regular or as transparent as the other portions of the cornea, but is cica- tricial, and constitutes an opacity. KERATITIS PHLYCTENULARIS. Herpes cornece, Keratitis pustulosa or phlyctenularis (Plate III, Fig. 1) is one of the most common forms of corneal inflammation; it may occur in adult life but much more frequently appears during childhood. The particular feature of the disease is the occurrence on the cornea of papules, vesicles, or pustules, similar to those which characterize phlyc- tenular inflammation of the conjunctiva, and it is often simply an extension of that disease. When situated upon the margin of the cornea they are frequently small, and few in number, or numerous enough to encircle its periphery. When occur- ring upon the corneal surface they may be single or multiple, but there is always a bundle of minute vessels in the scleral conjunctiva which extends to the vesicle, and when a leash of vessels is developed in the cornea, as frequently happens in these cases, the term fascicular keratitis has been applied to PLATE Pblyctenular Keratitis. DiFfuse Keratitis. Hypopion KeratiHs Shaphyloma Corneae KERATITIS PHLYCTENULARIS. 239 it. Again, if there are several of these vescicles the whole O ' conjunctiva may be hypersemic and present a catarrhal inflammation. The phlyctenules consist of minute elevations of the epithelial layer by serous infiltration, probably about the terminal filament of the sensory fibres of the fifth nerve. In from twenty-four to seventy-two hours, the epithelial cover- ing ruptures and more or less corneal substance is lost, and a small ulceration occurs, accompanied with much photophobia from the exposure of the nerve filaments. If the case is a light one, the epithelium reforms in a few days leaving a small hazy portion at the point of attack. If the case is more severe, there is a greater loss of the cornea and the ulceration is deeper and may perforate, and the healing process proceeds more slowly and leaves a flattened surface or facet at the point, and a cloudy cicatrix or opacity remains. In some cases the whole cornea is seen covered with these small ulcers, and blood- vessels becoming developed through its superficial layers con- stitute a form of pannus. In bad subjects, one phlyctenule follows another, or successive crops appear, and the disease lasts for months. CAUSES. The disease results from mal-nutrition and im- proper hygienic surroundings, and hence is largely confined to the poorer classes. It occurs frequently and is very similar to phlyctenular inflammation of the conjunctiva. It occurs during dentition and at the age of puberty, and in children of a strumous habit, or who live almost exclusively upon a vege- table diet. In these cases, tlie disease becomes obstinate, frequent relapses occur, and the resulting opacities of the cornea interfere very greatly with the vision. It is often a sequela of measles, scarlet fever, and whooping-cough. SYMPTOMS. The symptoms are very similar to those of phlyctenular inflammation of the conjunctiva, except more marked in degree, and there is usually considerably more pain. There is intense photophobia and the child will remain all day in a dark corner, or lie upon the bed with its face buried in the pillows during the day, endeavoring to exclude every ray of light. It cannot open the eyes, and if the 2-iO DISEASES AND INJURIES OF THE EYE. attempt is made to examine them, there is a severe blepharo- spasm, and a view of the cornea can only be obtained by the use of a retractor under the upper lid. The introduction of an elevator, or the attempted separation of the lids with the tip of the finger, is followed by a gush of tears and the cornea is rolled up out of sight, but if the lid is kept elevated it soon turns down, so that a view of the eyeball is obtained. It will then be found that one or more small points of ulceration are present on the cornea, or the latter may be very vascular and the eyeball injected. If the case is severe or has existed for a long time, the conjunctiva is found thickened and shows considerable muco-purulent discharge. The lids are thick- ened and on attempting to open them blood frequently comes from the fissures at the external canthus. In the majority of cases, there is a pustulous eruption on the parts about the eye which will give us a clue to the condition. TEEATMENT. Attention must be given to the diet of the patient and it should be made as nutritious and as readily digestible as possible, the hygienic surroundings improved, and warm baths daily advised. The eyes should be protected from the light by a deep shade, or dark glasses, or a very loose bandage. The blepharospasm may be temporarily re- lieved, and the photophobia lessened by the use of ice-cold compresses and the instillation of atropine three or four times a day. The careful selection of the remedy, according to the indications here given, or from those under phlyctenular con- junctivitis, with a proper observance of the hygienic and dietic part of the treatment will result in a prompt cure of these cases without the use of topical applications. Arsenicum. Pustules appearing after measles; conjunctiva very red, photophobia, lachrymation, and thin, burning excori- ating discharge; the lids may be puffy or cedernatous and the children are often anaemic. Calc. curb. Large phlyctenules upon the cornea which have a tendency to spread and ulcerate. Photophobia is often intense and lachrymation profuse. The lids may be closed, red and swollen. The pains are more likely to be described as sticking. KERATITIS PHLYCTENULARIS TREATMENT. 241 Calc. iod. "When the tonsils and cervical glands are swollen. Calc. sulph.An extremely serviceable remedy when the cervical glands are enlarged. "When administered in the lower potencies brilliant cures often follow. Graphites. Intense photophobia, so that the child cries from pain when exposed to light, and must be kept in a dark room. The lachrymation is often profuse, thin and acrid, and there is burning and aching in the eyes. The external canthi are fissured and bleed easily. There is often an eruption on the face or behind the ears. The nostril is frequently exco- riated and discharges much mucus, or is covered with thick crusts. If this affection has existed for a long time the cornea may be vascular and pannus be present. Hepar sulph. Phlyctenules with intense photophobia, pro- fuse lachrymation and great redness of the eyes. The pains are throbbing and relieved by covering the eye, and from warmth. Mercurius sol. Pustulous inflammation following measles or scarlet fever with severe pains which are continuous, and aggravated at night. The photophobia and lachrymation are variable. The lids are often spasmodically closed, thick, red and swollen, and excoriated from the acrid lachrymation. Merc. nit. This remedy has been used in all varieties of phlyctenular inflammation with marked success. Pulsatilla. Usually in cases where the pustules have extended from the conjunctiva. The symptoms are all mild and the photophobia may be entirely absent, and the pains not characteristic and not always present. Rhus iox. Small phlyctenules on the edge of the cornea, often forming a circle, with great photophobia and profuse lachrymation. Blepharospasm is commonly present, and the child lies constantly upon the face making every endeavor to exclude the light. The conjunctiva is very red, chemosed, and the lids swollen and spasmodically closed retaining a large amount of tears which are forced out on attempting to open them. ' Sulphur. The symptoms may vary greatly; the pains are 16 242 DISEASES AND INJURIES OF THE EYE. sharp and sticking in character, worse after midnight, and the photophobia is usually very great, the lachrymation may be very profuse or entirely absent. The characteristic eruption of Sulphur and the aggravation from bathing in cold water, are frequently present. Among the other remedies which may be selected are Apis., Croton tig., Kali bich., Kali iod., Merc, proi, and Nux vomica. EERATITIS ULCEROSA CORNEAL ULCERS. In this disease we have a softening and molecular death of a portion of the cornea from accummulation of the infiltrated cells at that point. Various forms of ulceration of the cornea are presented, and they are conveniently divided for clinical purposes into two classes, the sthemc and asthenic. Those of the sthenic type are accompanied by photophobia, pain, ciliary injection and lachrymation, and present usually a grayish base with perhaps swollen edges, or the infiltration extending beyond the limits of the ulcer. In the asthenic ulcer, there is little or no pain, photophobia or lachrymation. Either form may be superficial or deep. Two dangers are presented in ulcerations of the cornea, viz: changes in its transparency or opacities, and perforation of the cornea and involvement of the iris and the deeper tissues of the globe. Corneal ulcers may present an acute or chronic form; in the former the danger of perforation is greater, while in the latter, opacities are more likely to result. CAUSES. As the corneal tissue has no direct blood supply for the greater portion of its extent, its integrity suffers from any cause which interferes with its nutrition. This may occur from the want of proper nourishing elements in the blood, as in debilitated subjects, ill-nourished and scrofulous, or syphi- litic children, or after prostrating diseases as typhoid fever, anaemia, and the exanthemata. Again its nutrition may be interfered with by other forms of keratitis, or violent inflam- mations of the' conjunctiva* which obstruct the circulation of blood in the marginal loops of the cornea. The other forms KERATITIS ULCEROSACORNEAL ULCERS. 243 of Tilceration arise from deficient innerS r ation. A great majority are of traumatic origin, and injuries, even when very slight, may in weakened patients excite extensive ulceration. SYMPTOMS. The chief symptoms of ulceration of the cornea are photophobia, congestion and pain, which vary greatly in different cases. The photophobia is usually more severe in superficial than in deep ulcers, but its presence in any case should always lead to a careful examination of the cornea. The congestion consists of an injection of the vessels of the ciliary region and in some cases of the conjunctiva as well. The pain is also variable and is commonly referred to the parts around the eye rather than in the eye itself. One of the simplest forms of corneal ulcers is that which occurs in phlyctenular inflammation. Another variety consists of a small grayish spot of infiltration which occurs at the centre of the cornea, which in the first stage shows a slight elevation, later, a depression, and the infiltration extends somewhat around the ulcer into the corneal tissue. The patients are young and poorly-fed children. The ulcer is slow to heal and generally leaves an opacity, or may spread and involve a large portion of the cornea in suppuration. Another variety occurs in anaemic and strumous children with granular lids; one or more ulcers may appear and be attended with little infiltration, and after a chronic course, finally heal and leave a transparent depression or facet. Superficial ulcers may appear without much, if any, infiltra- tion and tend to extend over the greater portion of the surface of the cornea, while other forms may tend to involve the deeper layers rather than the superficial. Again, we find other forms of ulceration which, while perhaps not of great extent, show a most decided tendency to perforation. The infiltration of the base of the ulcer is variable, or it may even be absent. The corneal tissue is sometimes thrown off without marked infiltration or congestion, as in the chipping ulcers. Again, the base may be grayish, white or even yellow, and the infiltration extend to a variable distance into the corneal tissue. 244 DISEASES AND INJURIES OF THE EYE. Some cases present a development of blood-vessels into the ulcer from the beginning, as in vascular ulcers, or when occur- ring later they may be an indication of repair, bringing an increased amount of nourishment to the part, and, as the ulcer heals, dwindle down and disappear. One of the most severe forms of ulceration is the serpiginous,. crescentic, marginal, or ring ulcer, of old and ill -nourished people, or occurring during the progress of a purulent conjunc- tivitis. "When occurring in elderly people it is often slow in its progress, but cases are also presented where it is rapid and runs its course in one to two weeks. There is much photo- phobia, pain and congestion. A small excavation appears just within the corneal margin and soon extends until the centre is more or less completely surrounded by a furrow, which increases in depth, until the inclosed central portion of the cornea becomes infiltrated from its nutrition being cut off, and turns grayish, or yellow, and sloughs and the whole cornea is destroyed. COMPLICATIONS. In all forms as the ulceration extends deeper there is danger of perforation of the cornea. In the majority of cases the corneal tissue is destroyed until the membrane of Descemet is reached, which affords some resist- ance to further destruction and bulges forward from the pressure of the intra-ocular tension and presents as a small vesicle in the floor of the ulcer, or if the ulcer is of great extent, it may appear as if the process of repair had set in and the ulcer had become partially filled. In all cases the condi- tion should be examined by focal illumination which will reveal the bulging of Descemet's membrane as well as the depth and extent of the ulceration. If there is no interference in these cases the membrane ruptures and the contents of the aqueous chamber are discharged, and the iris and the lens move forward. If the opening is large the iris protrudes through the aperture, forming what is termed a prolapse of the iris. The protruded portion appears as a brownish nodule surrounded by the grayish or yellowish margin of the ulcer. If the lens comes in contact with the internal opening in the cornea, a. KERATITIS ULCEROSACORNEAL ULCERS. 245 partial capsular, or pyramidal cataract, results. As the ulcera- tion heals, the iris may be freed by the establishment of the anterior chamber or becomes caught in the cicatrix. Again, in some cases, the opening made by the ulcer becomes lined by the endothelium from Descemet's membrane and exists as a corneal fistula; in this case a minute drop of aqueous may be seen oozing through, when pressure is made upon the globe, and the depth of the anterior chamber is found dimin- ished and the iris drawn forward towards the opening. Hypopyon, (Plate III, Fig. 3), or a collection of pus in the anterior chamber is a complication of ulceration when the latter arises from, or takes on, a suppurative form. TREATMENT. Ulcers arising during the inflammatory affec- tions of the conjunctiva, or cornea, require that the original affection should be allayed by proper treatment. The general condition of the patient must always receive attention. In all cases of ulceration of the cornea, atropine solution is indicated and should be applied frequently enough to cause a full dilata- tion of the pupil. Atropine is particularly indicated if the ulcer is central and sthenic. If peripheral and asthenic an eserine solution is more suitable. As the discharge from the conjunctiva or ulcer is often septic and irritating, the use of a solution of boracic acid (gr. x ad fsi), or dilute chlorine water (1 to 3), dropped into the eye every hour or two, will aid materially the process of repair. If the ulcer is sthenic, rest in bed and cold applications, together with the use of atropine or eserine are necessary. A non-stimulating diet should be prescribed. If asthenic, hot fomentations or hot compresses should be used, atropine or eserine as before, and a generous and stimulating diet. A pressure or retaining bandage will often prevent the extension of the ulceration, secure rest and hasten repair. If the floor of the ulcer is very thin it is better to avoid sponta- neous rupture by opening the anterior chamber by the opera- tion of paracentesis corncce, which is made with a Desmarre's paracentesis knife (Fig. 92), or a broad needle (Fig. 93) ; the lids are held apart and the eyeball held by a pair of fixation 246 DISEASES AND INJURIES OF THE EYE. forceps, the knife is passed through the cornea near the sclero-corneal junction below, or at the outer side and inde- pendent of the seat of ulceration. After the knife has entered the anterior chamber, taking care to avoid wounding the iris or lens, or causing a prolapse of the iris, it is then slowly FIG. 92. FIG. 93. withdrawn, slight pressure being made at the same time upon the lower margin of the wound. The operation is not very painful and may be done without ether. The wound may require opening daily with a fine probe until all danger is past. Simple puncture of the floor of the ulcer by a fine needle may be sufficient, and the aqueous allowed to drain off slowly, care being taker to prevent wounding the iris or lens during the proceeding. This must be repeated as often as may be necessary to relieve the pressure. The patient must be con- fined to bed and atropine or eserine used, and a pressure bandage applied. Where the ulceration is deep or exhibits a suppurative tendency, SaemisJi's operation as proposed for the serpiginous ulcer may be used. The point of a narrow cata- FIG. 94. ract knife is introduced into the sound tissue on the temporal side of the ulcer, passed into the anterior chamber and then carried through the aqueous humor beneath the centre of the ulcer, and made to emerge in the sound cornea! tissue on tlie other side of the ulcer. The knife is then made to cut its way through the cornea to prevent the sudden expulsion of the aqueous. Although the sensibility is not very great, it is permissible to use ether for the operation. The wound will have to be opened daily with a fine probe or Weber's probe- pointed lachrymal knife (Fig. 94). CORNEAL ULCERS REMEDIES. 247 After any of these surgical procedures atropine or eserine, as may be advisable, should be instilled and the pressure bandage applied. When fistula of the cornea occurs or remains after the ulcerated process has passed, the opening may be closed by touching it lightly with a fine point of lunar caustic and a bandage applied, or the surface of the fistula abraded with a fine cataract needle. If these procedures fail, the application of poultices may produce sufficient stimulation to close it, or an iridectomy may have to be made. The results of ulceration of the cornea are opacity, anterior synechia, prolapse of the iris, keratocele, and leucoma adhe- rens or adhesion of the iris to the cicatrix. REMEDIES. Aconite. Superficial ulcers arising from injuries. It may be used both internally and externally. Arsenicum. Corneal ulcers occurring in weak anaemic chil- dren. They are often superficial and have a tendency to recur. The photophobia is excessive and the lachrymation acrid and burning. The pains are more frequently burning and aggra- vated after midnight. Small grayish central ulcers which occur in young children and tend to perforate. Aurum. Vascular ulceration of the cornea and ulcerations occurring during the course of pannus, or as the result of abscess. There is much photophobia, profuse scalding lachry- mation and sensitiveness of the eye to touch, and pains appar- ently extending from the parts around the eye to the eye, and aggravated by touch. Gale. curb, and Calc. hyperphos. Ulcerations occurring in ill-nourished patients which show a tendency to slough, or which result from abscess. Conium. Some superficial ulcers without much pain or redness but with intense photophobia. GrapliHes. In some cases of ulceration of the cornea which have followed attacks of phlyctenular inflammation of the cornea or conjunctiva. 248 DISEASES AND INJURIES OF THE EYE. Hepar sulphur. A valuable remedy for all ulcers or abscesses where there is pus in the anterior chamber. There is usually a marked sloughing tendency and the pain is throbbing and the photophobia intense, while the conjunctiva is often red and thickened or chemosed. There is relief generally from bandaging the eye and the application of warm compresses, although there is great sensitiveness of the eye to touch. Ignatia. Small chipping ulcers without much discomfort, which occur in connection with derangements of the digestion ; also small pinhole ulcers which are attended by photophobia and sensation as if something was in the eye, in nervous and hysterical patients. Mercurius. Often indicated in both superficial and deep ulcerations. There is generally grayish infiltration of the base and around the ulcer which is also often vascular. The discharges from the eye are profuse, thin and excoriating. There is a general aggravation at night. Concomitant symp- toms more frequently decide upon the particular form of Mercury to be administered; the eye symptoms indicating Merc. cor. being more intense and there is much ciliary injec- tion and pain. Merc, nit More useful in those ulcerations which partake of a phlyctenular character. Merc. prof. Ulcerations occurring with pannus; its efficacy in ulcus serpens is very doubtful and it has not proved as use- ful as Calc. phos. or Silicia in these cases. Nux Vomica and Pulsaiilla suit some cases of superficial ulceration with intense photophobia, and it becomes very difficult to differentiate between them when marked concomi- tant symptoms are not present. Silicia. Indicated in some cases of sloughing ulcers of the cornea, as in the marginal ulcer, and when small> funnel- shaped non-vascular ulcers appear near the centre of the cornea and rapidly perforate. Sulphur. When the ulceration is indolent and tends to slough this remedy will be useful. There is often considerable infiltration around the ulcer but no vascularity. The photo- KERATITIS: INTERSTITIAL- NON-VASCULAR. 249 phobia, lachrymatioii and other symptoms .are variable. The fibarp sticking pains which are commonly present and worse after midnight are very characteristic. The subjects are strumous and the general condition is indicative of Sulphur. Many other remedies may have to be consulted for individual cases. KERATITIS DIFFUSA. Parenchyrnatous or Interstitial Keratitis (Plate III, Fig. 2) is the result of an infiltration of the corneal tissue from a proliferation of the corneal cells without changes in the epithelium or anterior elastic membrane. Both eyes are usually affected, but an interval of several weeks, or months, generally exists between the onset of the disease in the two eyes, the second being perhaps attacked while the first is recovering. The disease runs a protracted and tedious course extending over six or tAvelve months, but as the cornea rarely ulcerates the infiltration gradually disappears and leaves the cornea clear, and if the iris or choroid have not been impli- cated slight or no permanent damage is done. Two forms are to be considered, one characterized by dense infiltration without development of vessels in the cornea and the other presenting a general vascular condition of the cornea. They are both local manifestations of a constitutional derangement of the system. DIFFUSE NON-VASCULAR KERATITIS. SYMPTOMS. The non-vascular form begins with a haziness of the cornea which may be central or marginal. This cloudiness becomes more opaque and advances slowly over the cornea until the whole surface is covered and presents a steamy or ground-glass appearance, having lost its transparency and lustre, and hides the iris from view. This opacity will vary with different cases in different portions of the cornea from a slight haziness to a dense white opacity, or present more dense spots iii some points than in others. Occasionally yellow spots are seen. When the inflammation has reached its height the 250 DISEASES AND INJURIES OF THE EYE. corneal epithelium presents a stippled appearance as if pricked with a needle. With tho beginning of the infiltration there is slight photophobia which may be more marked later, or disap- pear. There is slight ciliary injection which increases as the disease progresses, or upon exposure to light during exami- nation, or from irritation. The conjunctiva is scarcely affected and there is usually slight lachrymation. Pain may be entirely absent except by exposure of the eye to light or if the iris becomes implicated. CAUSES. The most common cause is hereditary syphilis. It appears during the ages of six and fifteen, sometimes as early as three ; rarely later than twenty. When occurring in adult life it may be the result of acquired syphilis, and occurs with the secondary symptoms, or in women it may be occa- sioned by some uterine disease. No assignable cause can be found for it in other cases. When the disease appears in children, other symptoms of constitutional syphilis will be present in the child or mother. The child may present, per- ,,f"""T,'r?;:vn.r,r FIG. 95. FIG. 96. haps, evidences of a former iritis or some of the well-known signs of inherited syphilis in the teeth, skin, bones or physi- ognomy. The most distinctive of these are the notched teeth of Hutchinson as shown in Figs. 05 and 96. The evidence of congenital syphilis, as exhibited by the teeth, consists in a crescentic notch in the lower margin of the central incisors of the permanent teeth, giving them a chisel-like appearance, while the later incisors and canines are often peg-shaped and irregularly placed in the jaw. This condition of the teeth should not be mistaken for the serrated margins of the per- manent teeth, which are more frequently found in children who have suffered from .prostrating diseases during the early periods of the development of the teeth of second dentition. The skin in these patients often presents a peculiar yellowish KERAT1TIS: NON-VASCULARVASCULAR. 251 or earthy color and is loose and soft, and if the protuberant, square forehead, or broad, flattened nose bridge, and diseased condition of the bones occur, the evidences of inherited syphilis are complete. TREATMENT. No local treatment is necessary beyond the use of a solution of atropine if there is much pain or iritie complication. The duration of the disease is much shortened by the proper homoeopathic remedy and a nutritious diet. REMEDIES. Aurum mury^- This preparation is the one most frequently indicated in these cases of syphilitic keratitis. The symptoms are those of diffuse infiltration with moderate photophobia, and pain which is of a dull character and referred to the parts about the eye. Mcrcurius sol. The inflammation is more active ; there is usually more pain, greater ciliary injection and nocturnal aggravation than under Aurum, and the general concomitants of Mercury are present. Mercurius prot. Often useful when Merc. sol. does not act' promptly. Arsenicum. Diffuse keratitis with marginal vascularity. The photophobia is intense, the lachrymation profuse, and burning pains are complained of. The aggravation after midnight, restlessness and thirst are commonly present. Apis mel. With the infiltration of the cornea there is moderate injection of the ciliary region and photophobia. Febrile disturbance, thirstlessness, and drowsiness often accompanying the condition. Hepar sulphur. Often serviceable when there is much ciliary injection or pain, great photophobia, lachrymation and sensitiveness of the eye to touch. Baryta iod. When enlargement of the cervical glands, which are hard and painful on pressure, accompany the dis- eases of the cornea. Kali mur. Interstitial keratitis with occasional pain, mod- erate photophobia and redness. "252 DISEASES AND INJURIES OF THE EYE. Sepia. Diffuse keratitis, occurring in women suffering from uterine diseases. DIFFUSE VASCULAR KERATITIS. The vascular form begins as in the first variety; the cornea becomes infiltrated and hazy, but soon numerous small vessels ,re developed through it. They give to the cornea the appear- ance of spots of effused blood, or when the number of vessels is still more increased, the cornea assumes a dull red or fleshy appearance. The epithelium is loosened in some cases, but ulceration rarely follows. It occurs more often between the ages of ten and twenty years. Its course and duration are ^about the same as the non-vascular form. The photophobia, injection and pain are rarely more severe than in the simple diffuse form of keratitis, and as the disease progresses, the vessels disappear and the cornea again becomes clear, though small spots of infiltration and a clouding of the cornea may present for a long time. The disease is liable to be mistaken for pannus, but the smoothness of the cornea and the absence .of a granular condition of the conjunctiva of the lids will prevent an error of diagnosis. CAUSES. The causes are virtually the same as those of the .non-vascular form, and will appear in patients presenting evidences of congenital syphilis. This variety occurs much more frequently in strumous children presenting granular enlargement, and in girls at the age of puberty. TREATMENT. This is the same as that of the diffuse form, a,nd of the remedies already considered in that condition, Aurum, Arsenicum, Baryta iod. and Hepar are more likely to Tae indicated; in addition to these, Cannabis sat. and Calc. phos. may be called for. After the inflammatory symptoms of either form have subsided Hepar s., Calc., Aurum mur. and Sulphur will be useful to clear up the opacities remaining. PANNUS OR SUPERFICIAL VASCULAR KERATITIS occurs when the epithelial layer of the cornea is irritated, blood-vessels Toeing developed in the epithelial layer from the capillary loops at its periphery. It occurs as a result of the irritation KERATITIS SUPPURATIVA. of the granular deposits in trachoma or froni the inversion of the cilia. It also appears in severe cases of phlyctenular keratitis. It differs from the disease just described, in that the vessels are well defined and distinct, and the corneal opacity is more dense. It begins on the upper portion of the. cornea beneath the upper lid. When pannus exists for a long time it may lead to softening and bulging of the corneal tissue. Treatment. Pannus disappears when the cause of the irri- tation has been removed, and its treatment has already been considered under trachoma and phlyctenular keratitis. KERATITIS SUPPURATIVA. Abscess of the cornea is 'characterized by a more or less local infiltration of pus cells to such an extent that a part or the whole of its structure is destroyed. The anterior layers, of the cornea may break down and ulceration occur, or if the underlying layers are destroyed, the pus is evacuated into the anterior chamber and hypopyon results, or again, the pus. may cause a separation of the lamellae of the cornea and sinks down to the lower portion forming an onyx. The infil- 1 tration may begin at one point, either central or peripheral, and show a yellowish spot or abscess, or may begin at the periphery and extend around the cornea forming a circular or ring abscess, and later the whole cornea becomes infiltrated and sloughs. The process may stop at any point and repair take place. Opacity is likely to remain from the destruction of the corneal tissue and its repair by less transparent material. Two varieties of the disease, acute and sub-acute, are de- scribed, but they present no distinctive clinical features as the symptoms of each form vary much. The acute variety is of a more sthenic character, with severe congestion, pain and pho- tophobia; while in the sub-acute forms there may be almost entire absence of acute inflammatory symptoms, pain and photophobia, but the disease progresses rapidly to the com- plete destruction of the cornea. 254 DISEASES AND INJURIES OF THE EYE. CAUSES. The acute form generally occurs in feeble const! tutions as a result of injury, operations upon the cornea as in cataract extraction, cold and severe inflammation of the con- junctiva, as in ophthalmia neonatorum and other varieties of purulent conjunctivitis. The sub-acute form affects persons who exhibit a low condition of the system, due to want of nourishment, or is the result of debilitating diseases as variola, phthisis, typhus, or cholera, and in delicate, weak, children who do not receive proper nourishment. SYMPTOMS, DIAGNOSIS AND PROGNOSIS. In the acute variety, there is violent and severe pain which is referred to ths eyebrow and temple^ photophobia, lachrymation and ciliary injection, with perhaps chemosis and blepharospasm. The cornea is hazy and some portions present a grayish infiltration which soon becomes yellow at some point. The pus may escape externally and an ulcer form, or open into the anterior chamber, or gravitate between the corneal layers. If the pus does not find an exit the whole cornea becomes involved in the purulent infiltration. In mild cases under proper treatment the disease disap- pears, leaving behind only a slight corneal opacity; in more severe cases the hypopyon and iritis increase, the ulceration spreads and perforation of the cornea may take place, and a large permanent cicatrix, with perhaps adhesions of the iris, occurs, and the suppurative process involves the whole eyeball. The course of the disease depends upon the amount of tissue involved and whether ulceration or hypopyon follows. The iris is apt to be involved and iritis results which increases the danger. In the sub-acute form there is no marked symptom of inflammation, and the pain and photophobia are slight or absent. The prognosis depends upon the amount of cornea involved and its situation; if superficial, ulceration occurs, if more deep, the inflammatory process extends to the iris and choroid, the conjunctiva becomes congested and the destruc- tion of the cornea progresses still more rapidly. The prog- nosis then is generally unfavorable, but depends upon the seat, depth and extent of the suppurative process. KERATITIS SUPPURATIVA TREATMENT. 255 TREATMENT. Attention to diet is necessary and often a gen- erous or stimulating diet may be demanded. In slight cases rest, the use of atropine locally and a pressure bandage, together with the use of Hepar s., Calc phos., or Sulphur is all that is necessary, the pressure bandage being contra-indi- cated in violent inflammatory forms with profuse conjunctival secretion. In the acute form, cold applications may be used locally if pleasant to the patient, and in the sub-acute variety when it arises from conjunctival inflammation, but if the cold applications are not comfortable, hot applications should be used. Hot fomentations, by means of light compresses soaked in water as hot as can be borne, are to be applied for ten or fifteen minutes at a time, every two hours, until improvement is perceptible, when the applications must be made at longer intervals. If the abscess shows no signs of absorption, it may be opened with the point of a cataract knife, but this is rarely necessary under homoeopathic treatment. If ulceration occurs, it is to be treated as already described. If hypopyon results, the use of eserine may be indicated, or paracentesis of the cornea may be necessary. Perforation of the cornea is to be prevent- ed by the means advised in the treatment of corneal ulcers. The remedies useful in this form of corneal trouble are Hepar sulph., Calc. carb., Calc. hyperphos., Merc sol., Silic., and Sulphur, according to the indications given. Hepar sulph. Abscess and sloughing, or sloughing ulcers, of the cornea, when accompanied by hypopyon. Photophobia intense, lachrymation profuse, and there is great redness of the cornea and conjunctiva, with severe aching, throbbing pains; relief from warm applications, and aggravation from colds. There is marked sensitiveness of the eye to touch. Calc. carb. Cases occurring in children with the concom- itant indications of calcarea. The pains, redness and photo- phobia are variable. Calc. hyperphos. In weak, debilitated individuals where there is great purulent infiltration and tendency to sloughing. Calc. sulph. -Very useful in many cases of purulent infil- tration of the cornea occurring in debilitated subjects. 256 DISEASES AND INJURIES OF THE EYE. Merc. sol. In abscess of the cornea when there is a gray- ish infiltration extending some distance beyond the abscess. The conjunctival redness and photophobia are marked, while the lachrymation may be profuse and acrid. There is aggra- vation of the condition at night and from either very cold or very warm applications. Silicia. Abscess of the cornea with hypopyon. The pain, photophobia and redness are not characteristic. There is, generally, relief from wrapping the head or bandaging the eye. Sulphur. Not infrequently indicated in suppurative inflam- mation of the cornea in strumous constitutions. The sharp sticking pains of the eyeball, which occur more often after midnight, are very characteristic. NEUBOPAEALYTIC KEBATITIS is a somewhat rare disease which occurs in consequence of wounds or injuries of the superficial branches of the fifth nerve, or paralysis of the nerve itself due to intra-cranial causes. There is loss of sensibility of the cornea, the conjunctiva becomes dry, and the cornea cloudy, infiltrated, and is rapidly destroyed. The intra-ocular tension is lessened. In some cases the presence of a foreign body in the folds of the conjunctiva, or slight injuries of the cornea, seem adequate to produce sufficient innervation in debilitated subjects to impair the nutrition of the cornea. Treatment. The removal of the cause and the application of a bandage will, in slight cases, suffice to cause a return to the normal condition. In any case, the eye should be pro- tected from external irritation by the closure of the lids and the same treatment used as in other forms of corneal suppura- tion. In addition the use of the constant galvanic current will prove of value. KEEATTTIS PUNCTATA or Descemetitis is a term given to the dotted opacities which occur upon the membrane of Descemet. It is almost always the result of disease of the iris or ciliary body. When originating in the cornea, there is usually slight pain or considerable ciliary injection, with dimness of the vision from the changes of the endothelium. The punctated appearance takes a triangular form with the apex towards the CORNS AL OPACITIES. . 257 centre of the cornea. The disease is apt to be protracted and tedious. Treatment. Gelsem. and Kali bich. and the use of atropine are sufficient to clear up the condition in the majority of cases. Those cases occurring during the progress of iritis and cyclitis will be considered in the chapter devoted to these diseases. CORNEAL OPACITIES. Every possible variety of opacity as regards extent and density occur as the result of inflammatory changes in the cornea. Slight opacities, due to the healing of superficial ulcers are called nebulce or maculae; when they occur in very young children they may disappear entirely. Dense white opacities, leucomata, occur as a result of deep ulcers. Even these, in children, may clear up considerably in time. If the entire cornea is opaque the condition is known as leucoma totally. If the iris is adherent to the cicatricial tissue, it forms a leucoma adherens. The effect upon the vision depends largely upon its situation and density. If central, even the most delicate clouding is very destructive to vision, while very dense opacities, if the centre be clear, do not interfere materially with the vision. These opacities are not infrequently productive of squint, and also cause a blemish which the patient is always anxious to have removed. Improvement in the condition may be expected as long as the inflammation which caused the opacity continues, but no improvement is likely to take place after that has .disappeared. TREATMENT. The internal administration of Calcarea, Aurum, Hepar, Cannabis, and Silicia, will oftentimes cause a very rapid and wonderful improvement in the transparency of these cicatricial spots. The application of some stimulant directly to the opaque portion is usually indicated where there is no vascularity of the cornea remaining. For this purpose a great variety of solid and liquid irritants have been used. Almost anything which will produce a slight irritation of the cornea which lasts for fifteen or twenty minutes will be useful. 17 258 DISEASES AND INJURIES OF THE EYE. The following have proved very useful when applied directly to the opacity: sulphate of soda, kali bich., calomel, sulphate of copper and aluminate of copper. Recently, I have had most excellent results from the application of Resorcin, in powder, to the opacity. Stenopaic glasses by lessening the irregular refraction of light may be beneficial, but are rarely worn. If a clear portion of the cornea remains, then an iridectomy by making a new pupil will materially improve vision. Finally, an opacity of the cornea which is white and conspicuous may be tattooed with india ink, by means of a small bundle of fine needles as in Fig. 97. The lids should be held apart by the speculum, and the cornea dried by absorbent cotton which is also used to prevent the washing away of the ink, which is pricked into the substance of the cornea by the needles. A fine-pointed steel pen is often more efficient than the needles. Several sittings will usually be required. The irritation following the introduction of the ink is usually not very great. The ink is absorbed after a time and the tattooing will have to be repeated. RIBBON-SHAPED OPACITY is a faint hazy opacity which crosses the cornea transversely in the horizontal meridian. It progresses very slowly and is supposedly due to deposits of calcareous salt in the cornea. It occurs in old people and accompanies other degenera- tive changes in the eye or may be the forerunner of a glaucomatous condition. LEAD DEPOSITS are dense white opacities which result from the use of lead washes in the treatment of no. 57. eye affections when there is corneal ulceration. They may be removed as far as possible by carefully scraping them off with a knife, when the remaining opacity will gradually clear up. ARCUS SENILIS is an opacity which appears after middle life. It is confined to the margin of the cornea and is due to tatty degeneration of the corneal tissue; it occurs in the upper, STAPHYLOMA CORNER KERATO.CORNUS. 259 afterwards in the lower portion, and then encircles the cornea. There is a transparent portion between the opacity and the corneal margin. STAPHYLOMA CORNER (Plate III, Fig. 4) is a protrusion of the cornea caused by the pressure of the intra-ocular fluids during the process of healing which follows suppurative inflammation of the cornea while the tissue is soft and yielding, and occurs more frequently in children. It may be prevented, to some extent, by the use of Calc. phos. internally and the frequent puncture of the protruded portion, thus lessening the tension, until the cicatricial tissue has become more resistant. A large iridectomy may prove beneficial in arresting the staphyloma. When it has become total the vision is lost and the choice lies between the removal of the whole eyeball or its anterior part only, and removal of the contents of the eye. The latter operation leaves a better stump for an artificial eye, and the danger of any sympathetic trouble is not very great in this case. The operation for evacuation of the eyeball is made in the following manner: The patient is put under the influence of ether and the eyelids separated by a speculum. The ciliary region is then transfixed by a Beers knife held parallel to the front of the eye and the anterior portion completely removed; the interior structures are then entirely removed by wiping them out with small balls of charpie which are held by forceps, until nothing remains but the scleral envelope. The conjunc- tiva at the outer anterior margin of the sclera may be brought together by two cross sutures and a light dressing applied. The reaction is apt to be great in some cases and may be prevented by the use of ice compresses for twenty-four hours. The stump is in a condition to wear an eye in about a month after the operation. KERATO CORNUS or Conical Cornea (Fig. 98) is a conical protrusion of the cornea due to atrophy of the elements of the true corneal tissue, thus lessening the resistant power of this membrane. The change comes on insidiously, the patient finding his 260 DISEASES AND INJURIES OF THE EYE. vision less distinct yet experiencing no pain, nor is there any- particular injection. The increased convexity of the cornea, may be scarcely noticeable, but as the disease progresses the apex of the cornea projects between the lids, and being no longer protected, becomes rough and finally opaque. The protrusion may cease, however, at. any stage, and scarcely ever ruptures, as the corneal tissue becomes so thin at the apex that the aqueous filters- through. It occurs usually between fifteen and twenty years of age and in delicate individuals. Both eyes are affected generally, but in clif- FIG " 98> ferent degrees. The vision is very greatly diminished owing to the abnormal curvatures and from the elongation of the axis of the eyeball, and there is slight improvement from concave glasses. The diagnosis is easily made if the disease has progressed to any extent, as the conical shape of the cornea is easily seen when viewed in profile. All cases of rapidly progressing myopia with amblyopia should be carefully examined to deter- mine whether it is due to the conical projection of the cornea. Treatment. Moderate degrees may be much benefited by the internal administration of Calc. iod. and Cannabis, and the constant instillation of atropine, together with the use of a. pressure bandage when the disease is in a progressive stage. If the progress is extremely slow, or has ceased, a careful study of the refraction and the use of combined cylindrical and spherical lenses may improve the vision. Lately it has. been proposed to grind lenses with such parabolic curves as. should give the best results in improving the vision. In extreme cases Von Graefe's operation may prove useful. Thia consists in shaving off the apex of the cornea until half its thickness is removed and allowing the wound to heal; the resulting cicatrix flattens the cornea somewhat, and an artifi- cial pupil is then made by an iridectomy and the central scar tattooed. TUMORS OF THE CORNEA. 261 The operation of Bowman consists in trephining the cornea with a small trephine which removes a circular disc from its centre and the wound treated in the same way as in Graefe's operation. KEKATO-GLOBUS is a general enlargement of the whole cornea and is a congenital condition, or may result from severe cases of pannus or vascular keratitis, which produces a soft- ening of the corneal tissue which allows of its distention. Treatment. Little can be done to improve the condition of the patient beyond the application of a pressure bandage. The removal of a large section of the iris may be beneficial. TUMORS OF THE CORNEA. Tumors of the cornea occur very rarely. They are com- monly dermoid tumors which arise from the corneal margin and involve both the cornea and sclera and are usually congen- ital. They are white or brown in color and small in size and may present hairs. They are readily removed by the knife. EPITHELIOMA is a very rare affection and appears also at the corneal margin. Dr. T. F. Allen reports a case where the growth encircled the cornea which cleared up very markedly under the use of Hepar s. and Calc. carb. MELANOMA and SARCOMA may appear at. the corneal border and should be thoroughly removed as soon as possible. CHAPTER XIL DISEASES OF THE SCLEEA. ANATOMY. The sclera, or sclerotic coat of the eye, is a strong, opaque, unyielding, fibrous structure, the outer surface being white and smooth except where the tendons of the ocular muscles are inserted. It is thinnest anteriorly about one-fourth of an inch from the cornea and thickest at the posterior portion where the sheaths of the optic nerve unite with it. The optic nerve pierces the sclera about one-tenth of an inch to the inner side of the axis of the eyeball, and the opening is some- what smaller at the inner than at the outer surface of the coat. The sclera consists of connective tissue fibres combined with fine elastic tissue, and amongst these lie connective tissue- corpuscles lodged in cell spaces, similar to but not as regularly arranged as those in the cornea. The fibre bundles are disposed in layers both longitudinally and circularly, the longitudinal arrangement being most marked on the surface. These layers interlace and form a dense meshwork. A few blood-vessels, in the form of capillaries with wide meshes, are distributed through its texture. Upon the surface of the sclerotic near the cornea, when this region is congested, are seen a number of vessels which are derived from the muscular and anterior, ciliary arteries ; they are not movable as are the overlying vessels of the conjunctiva. These sclerotic vessels dip in near the cornea and appear to unite with a 262 DISEASES OF THE SCLERA SCLERITIS. 263 deeper capillary network disposed in closely set lines which radiate from the margin of the cornea, and are visible when the sclera becomes inflamed. At the anterior edge of the inner surface of the sclera a circular canal, the canal of Schlemm, lined by endothelial cells, gives passage to various plexuses of vessels from the sclera, and the ciliary veins, which communicate with the anterior chamber and the anterior ciliary veins. In its anterior portion the sclera gives passage to the anterior ciliary arteries, veins and nerves; at the equator to the venae vorticosae from the choroid, and more posteriorly to the posterior ciliary arteries and nerves. The sclerotic derives its blood supply from the anterior ciliary system and from the arteries about the optic nerve entrance which form a posterior vascular zone. The presence of nerves in the sclera has not been satisfac- torily demonstrated. The inner surface of the sclera is grooved for the passage of the ciliary arteries and nerves and is brownish from the pres- ence of pigment cells, and is closely connected to the choroid and ciliary body by the lamina fusca, the loose trabecular tissue over which are disposed endothelial cells and which forms the lymph space existing between the sclera and the choroid. The outer surface is somewhat rough and connected by loose connective tissue to the s"heath of the globe, tunica vaginalis or Tenon's capsule, and anteriorly is connected to the conjunctiva by shorter filaments of subconjunctival tissue. DISEASES OF THE SCLEKA. The sclera, owing to its very moderate blood supply and almost total absence of nerves is rarely the seat of acute inflammatory action, except from extension of diseased condi- tions of the cornea, iris, ciliary body and choroid. In the normal condition, the sclera appears of a bluish white color upon which are seen the blood-vessels of the overlying conjunc- tiva, at its anterior portion an anastomosing ring of vessels, the 264 DISEASES AND INJURIES OF THE EYE. scleral or ciliary zone, becomes apparent upon any inflamma- tory affection of the cornea, iris or ciliary body and constitutes an hyperaemia of the sclera. Inflammation of the sclera is characterized by the formation of new blood-vessels and infiltra- tion of cells, which may result in thickening, or lead to softening with thinning and distention of its tissue. SCLERITIS. Inflammation of the sclera presents a dusky crescent of con- gested vessels usually upon the outer side of the cornea, or purplish spots appear upon the anterior portions of the sclera, more frequently about the insertion of the recti muscles where we have a greater blood supply. There is swelling of the portions of the sclera affected, with dull pain, lachrymation, and fatigue on use of the eyes. The margin of the cornea may be invaded and the sclero-corneal junction appears irregular and new tissue formations occur in the cornea. The inflamma- tion is of a low type, and if it does not appear in the ciliary region, gradually extends to it, and involves the cornea. CAUSES. It is more commonly seen in women and appears to be connected with uterine irritation, suppressed menstrua- tion and cessation of uterine functions. In men it is often associated with a rheumatic or gouty diathesis. In young people it seems to be dependent upon malarious causes. Some cases may be traced to a syphilitic taint, and a small gummy tumor may make its appearance in the sclera. SYMPTOMS. Beyond the dusky appearance of the sclera at the point affected, the dull pain, and the absence of any dis- charge, there is little to call attention to the disease, as the vision is very rarely affected, and when the latter is disturbed, it arises from the extension of the inflammation to ihe choroid. PROGNOSIS. The progress of scleritis is usually very slow, often lasting for months, and if the inflammatory process involves but a small portion of the sclera, the natural tendency of the affection is toward recovery. If the inflammation is extensive, or situated near the corneal margin, the sclera may SCLERITIS ZPISCLERITIS. 265 Tmlge forward changing the relation of the interior struct- ures and thus injure the vision, or, as is not infrequently the case, the choroid or ciliary body become involved in the inflammatory process and the danger to the eye is thereby increased. Again, the cornea may suffer from ulceration, or opaque tissue be formed in its structure and encroach upon the pupil and thus interfere with the vision. The disease shows a strong tendency to recur and the softened sclera yields to the intra-ocular pressure and staphy- loma results. Occasionally there is a marked increase of the intra-ocular tension which may necessitate operative measures. TREATMENT. The local symptoms are very meagre and the general symptoms of the patient must be carefully considered in making our prescription. No local applications are admis- sible excepting the use of atropine, when the cornea or iris become involved. Among the internal remedies which may be called for in this disease are Ars., Merc, prot., Aurum mur., Thuja, Nux mosch., Silicia and Kalmia lat., in the order given. If there is much increase of tension an iridectomy may be necessary. EPISCLERITIS is a term which formerly included all the forms of scleral inflammation, but should be confined to those partial inflammatory affections of the episcleral tissue which present appearances similar to scleritis. The tissue of the conjunctiva over the inflamed portion is hyperremic, but there is no conjunct! val discharge. The pain is often more severe than in scleritis, and the disease will exhibit the same tendency to recurrence, but is not as obstinate, and the attacks are much shorter. Causes. The cause is rarely determinable, but the con- dition occurs in rheumatic and gouty cases more frequently than in others. Treatment. In addition to the remedies noted for scleritis, Terebinth, Sulph. and Puls. may be indicated. ScLEROTico-CnoROiDiTis ANTERIOR or anterior siaphyloma of ihe sclera may arise by the extension of the inflammatory softening or atrophic process of the cornea, or as the result of 266 DISEASES AND INJURIES OF THE EYE. clioroiditis, scleritis, or intra-ocular tumors. The thinnest part becomes prominent and bluish and the internal parts of the eye are usually distended and atrophied. It may be partial or total. When the whole anterior portion of the eye is involved, the disease is called Biqihthalmus; if the whole eye- ball is affected it is called Hydrophthalmus. The vision is usually lost from the implication of the nerve structures, and enucleation is often advisable. The condition may lead to a glaucomatous degeneration, or sympathetic inflammation of the other eye. Causes. Anterior staphyloma of the sclera may arise from an iritis which has involved the angle of the iris and the canal of Schlemin, or from irido-cyclitis, or incised wounds in the ciliary region. Symptoms and Diagnosis. The bulging of the sclera, in whole or in part, is unmistakable when present. Treatment. Nothing can be done for the condition when it has become once established, except to remove the eyeball if it becomes a source of irritation to the other, or when the projection of the sclera is such as to require relief for cosmetic purposes. Here enucleation will be necessary, unless the whole eyeball is involved, when evacuation of the contents of the globe as described under staphyloma corneas will be better, as the great enlargement of the globe results in the absorption of the contents of the orbit to a considerable extent, and the removal of the whole eye under these circum- stances does not leave sufficient cushion for an artificial eye to make it sufficiently prominent for cosmetic purposes. SCLEROTICO-CHOROIDITIS POSTERIOR, or posierior siaphy- loma of the globe is much more frequent than that just described and is the productive cause of many cases of myopia. It usually occurs at the posterior pole on the temporal side of the optic nerve, and, with the ophthalmoscope, appears as a perfectly white spot from which the choroid has been retracted, and appears either as a crescent, or later, involves the whole of the sclera about the optic nerve entrance and forms an irregular ring. SCLEROTICO-CHOROIDITIS POSTERIOR TREATMENT. 267 Treatment. The treatment consists in the use of those remedies which have already been considered when speaking of the secondary disturbance of myopia and the use of such hygienic measures as have been indicated in cases of pro- gressive myopia. CHAPTER XIII. DISEASES OF THE IBIS. ANATOMY. The iris is the contractile and colored membrane which is seen behind the cornea and which gives the tint to the eye. In the centre of this movable curtain is a circular aperture, the pupil. The pupil is nearly circular in form and is placed a little to the nasal side of the centre of the iris. It varies in size according to the contraction or relaxation of its muscular fibres, this variation ranging from ^ to | of an inch, and regulates the amount of light admitted to the eyeball. The membrane of Decemet, on reaching the angle of the iris, i. e. the space in the anterior chamber bounded by the posterior margin of the cornea and the anterior surface of the iris, breaks up into fibrillse of connective tissue, and these extend through half the breadth of the iris forming the lie/amentum pectinatum iridis, or the supporting ligament of the iris. The endothelial cells of the posterior surface of the cornea are continued upon the trabeculated tissue at the angle of the iris and pass forward, becoming smaller and more granular, upon the anterior surface of the iris itself. The anterior surface of the iris presents numerous furrows which take a radial direc- tion, except near the pupillary margin where they become circular. The tint of the iris results from an interference phenomenon of light, caused by its broken anterior surface, and from the brown pigment cells, which in dark eyes are 268 DISEASES OF THE IRIS. ' imbedded in the tissue of the iris. At its circumference we have the iris continuous with the ciliary body and choroid, the posterior surface being covered by a layer of dark pigment cells which is continuous with the uvea, the retinal layer of pigment which also covers the choroid and ciliary body. Between these two layers of cells, the epithelial anterior layer and the layer of pigment cells, just described, is the stroma of the iris, which consists of loose fibres of connective tissue, having a radial course towards the pupil, and a circular one at the circumference. These interweave with one another until a loose web is formed, which gives support to the pig- ment cells, which are branching and contain brown or yellow pigment. In this stroma we find the muscles, blood-vessels and nerves. The muscular fibres are arranged in plates and are of the involuntary variety ; one plate is disposed around the pupil (a Fig. S9) and is termed the sphincter, the other (6 Fig. 99) appears as rays which come from the circumference and run towards the pupil. The sphincter muscle is a narrow, flat band of muscular fibres -fa of an inch wide, on the posterior surface of the iris close to the pupilary margin. It is supplied by a branch of the third nerve. The dilator of the iris, the existence of which has been doubted, is a very thin layer of muscular fibres on the posterior surface of the iris stroma, covered and permeated by pigment cells. These radial fibres do not form a contin- uous muscle, but extend from the ciliary body in minute fascicles, which, as they approach the sphincter unite, forming arched plexuses which are partially lost in the sphincter. Vessels and Nerves of the Iris. The long ciliary arteries, TIG. 99. 270 DISEASES AND INJURIES OF THE EYE. two in number, pierce the sclerotic a little in front and on each side of the optic nerve, and run through the loose tissue between the sclera and choroid directly forward to the ciliary muscle a short space behind the fixed margin of the iris. These vessels branch above and below and form a circular ring of arterial supply, which is augmented by the anterior ciliary arteries which branch from the arteries of the recti muscles. These anastomosing form the arterial ring, or circulus major, from which small branches supply the muscles whilst others converge towards the pupil and when near the margin, form another anastomosing circle, the circulus minor, from which capillaries are continued inward and end in small veins, which, increasing in size, follow the arrangement of the arteries and pass into the canal of Schlemm. The nerves of the iris are derived from the ciliary nerve, which follows nearly the course of the blood-vessels, dividing into branches which communicate with one another as far as the pupil, there forming a close plexus of non-medullated fibres, whose ultimate termination is not known. DISEASES OF THE IRIS. Inflammatory diseases of the iris are very common and present several forms according to the nature of the inflam- matory product, and are the frequent accompaniments of acute or chronic diseases affecting the conjunctiva, cornea, ciliary body and choroid. IRITIS. Inflammation of the Iris, or Iritis (Plate IV, Fig. 1), is characterized by an engorgement of the vessels, the exudation of serum into its tissue causing a swollen, spongy condition ; the stroma cells become enlarged and their contents turbid, proliferation occurs and neoplastic growths result. Again, the product of the inflammatory action may be more plastic or lymph-like, the tissues become more swollen and stiff and the PLATE IV Irihis Iritis, irregular pupil Syphilitic Iritisf Condylorna) Irido-Choroiditis IRITIS SYMPTOMS. 271 exudation collects upon the surface or fills the pupillary space with a membranous formation; or, it may consist entirely of pus cells, which are found to extend through the iris tissue and destroy it, or appear upon the surface of the iris or collect in the anterior chamber, forming an hypopyon. While all these pathological features may be present during any attack of iritis, yet in the inflammatory diseases of the iris each case presents a more or less well-defined form of exudation. Clini- cally, there is no special distinctive feature of the inflammatory process which enables us to determine the cause. It will be better then to divide the various forms according to their pathology into serous, plastic, and suppurative varieties. CAUSES. Iritis may occur at any age and from a great variety of causes. It appears more commonly between the ages of twenty to fifty years, and more frequently in men than women and generally one eye is affected, or one eye is attacked, and disease of the other follows. Recurrent attacks are not uncommon. The most frequent cause being syphilis, inherited or acquired; when occurring in very young children, it is often indicative of inherited syphilitic taint. It may precede <*r accompany secondary symptoms of acquired syphilis, being more commonly observed during the eruption of the roseola, or it may appear months or years after the primary disease. Injuries and operations upon the Iris, or eyeball, and diseases of the cornea and conjunctiva, form the next most frequent causes. It frequently occurs idiopathically from sudden changes of the weather, exposure to wet or cold, particularly in ill-nourished and feeble persons, or in those exhibiting a rheumatic diathesis, and in patients suffering from gonorrhoea with, or without, gonorrhceal rheumatism. It may appear in young girls at puberty, or result from suppression of the menses. Finally, it forms a very important part of the dread disease, known as sympathetic ophthalmia. SYMPTOMS. The surface of the iris loses its lustre and striated appearance, and its color becomes dull and changed from the congestion and effusion into its structures, together with the turbid condition of the aqueous which occurs from 272 DISEASES AND INJURIES OF THE EYE. the exudation. The iris does not respond promptly to the stimulus of light, owing to the increase in its volume; it may be immovable from the gluing of its posterior surface to the lens from the plastic nature of the exudation. The pupil appears dull and in many cases is contracted or filled with lymph. If the attack is severe a large quantity of lymph is thrown out and collects upon the pupillary margin in minute beads or covers the surface of the iris, or extends across the pupillary opening. The eyeball is congested, particularly in what is termed the ciliary zone, that portion of the sclera immediately behind the cornea, where a zone about one-fifth of an inch wide exhibits a pinkish injected appearance due to the development of straight radiating vessels, branches of the anterior ciliary arteries, which appear larger at the corneal margin and disappear after extending a short distance upon the sclera. This condition is, however, masked by the conges- tion of the overlying conjunctiva. Owing to the great vascu- larity of the iris and its plentiful supply of sensitive nerves, its inflammation is very marked and accompanied by severe pain due to pressure of the nerve filaments by the exudation. The pain is not limited to the eye, but extends over the supra- orbital region and to the sensitive fibres of the fifth nerve, and is variable and neuralgic in character, worse at night and after midnight. There is usually great intolerance of light, but this is a variable symptom and not as constant as in corneal affections. Lachrymation is often copious, but there is no discharge of mucus or pus as in conjunctiva! diseases. The vision is misty or is much diminished from the aqueous becoming turbid from the exudation mixing with it, or from the pupil becoming occluded with lymph. The tension of the eyeball is often slightly increased. There may be consider- able febrile disturbance and a rise of one or two degrees in the temperature. There may be also a swollen cedematous condi- tion of the lids, this being more frequently the accompaniment of iritis following operations upon the eye, as after cataract extraction when it is an early indication of the commencing inflammation. In the acute forms of iritis, all these symptoms , 1R1 TISDIA GNOSISCOMPLICA TTONS. 273 are very prominent, but in the more chronic varieties there is great variation; the impaired vision with discoloration of the iris and the presence of adhesions between the lens and the iris, may be the only symptoms present. DIAGNOSIS. From the symptoms thus fully given, there should be little difficulty in recognizing the disease. The con- dition of the pupil as to color and mobility, when compared with the well eye, is more diagnostic than the other symptoms, and the use of atropine causes a dilatation of the parts of the iris between the adhesions, or synechiae, giving the pupil an irregular appearance (Plate IV, Fig. 2) when present, and is conclusive evidence of iritis, and enables a correct diagnosis to be made. In cases of iritis where the aqueous is cloudy the use of atropine clears up the anterior chamber, and gives a view of the iris while in keratitis when the cornea is hazy the condition is not changed. In the early stages of iritis, or when the hyperaemia has involved the vessels of the conjunctiva, the diagnosis may be difficult, but the presence of marked pain and a sluggish con- dition of the pupil in iritis and the absence of the discharge and of severe pain, which is present in conjunctival affections, will generally be sufficient to differentiate between the two dis- eases, and in all cases of doubt, atropine should be used, and if there are any synechise, they will become observable at once. From neuralgic affections of the ciliary nerves, it will be differ- entiated by an absence of pain and inflammation present in the purely neuralgic affection ; from cyclitis which may complicate the attack, it may be diagnosticated by the pain being more severe and the extreme sensitiveness of the ciliary region to touch in cyclitis. COMPLICATIONS AND SEQUELS. From the similarity of the structure and the common vascular supply of the iris, ciliary body and choroid, inflammation of the iris tends to involve these tissues. Diseases of the cornea or sclera often impli- cate the iris and thus render the situation more grave. The permanent results of iritis are adhesions to the lens capsule, or posterior synechise, and occlusion of the pupil by means of 274 DISEASES AND INJURIES OF THE EYE. organized exudation; the adhesions of the iris to the lens capsule may be slight, or extend over a greater portion of the surface, and thus interfere Avith the nutrition of the lens, and cause cataract. Defective sight is occasioned by these changes in the pupil or in the lens, and also by plastic exudation and pigment spots, which may be left on the capsule from the syiiechise, and if occurring in the pupil, or near its margin, cause the appearance of black spots in the visual field which prove very annoying to the patient. PROGNOSIS. If early recognized and properly treated the result is almost always favorable. The attack may be so slight as to disappear in a few days, yet if neglected or improperly treated may rapidly destroy the eye, or continue for months and end in atrophy of the iris tissue, or of the whole eyeball. Mild cases usually last for two or three weeks, but the duration depends more upon the severity of the attack and its methodi- cal treatment. TREATMENT. In every case of iritis, and whatever the cause may be, the first thing to be done is to use atropine to dilate the pupil, because it relieves the tension of the eyeball, pre- vents adhesions forming between the iris and the lens, or between the opposite margins of the pupil, which might other- wise become entirely blocked up with lymph. It also gives rest to the inflamed tissue and has a marked effect, in most cases, upon the severity of the pain. A drop of a four- grain solution of atropine is to be placed inside the lower lid, every half hour, until the whole iris, or such portions of it as are not bound down by adhesions, is fully dilated. Afterward a drop every two or three hours, or less, will be sufficient to keep up the impression made. If the pupil dilates fully and the atropine is kept up until all congestion has disappeared, the eye will recover without other treatment. If the adhesions of the iris are recent and not very extensive, the atropine will often tear them so that the pupil will again become regular, and further adhesions be prevented by keeping the pupil well dilated. If atropine is not well borne, which fortunately is rare, greater care must be exercised in instilling it into the IRITIS TREATMENT REMEDIES. 275 eye, and if much irritation or pain follows its use, or toxic effects appear, some other mydriatic, as duboisia, should, be substituted. Homatropine is comparatively valueless in the treatment of inflammatory diseases of the iris. All use of the eyes for near work must be forbidden, and the case will recover more quickly if confined to the house and, in severe cases, to the bed, where an equal temperature can be sustained, as all cases of iritis are quickly affected by changes in temperature or atmospheric influences. The eyes should be shaded from the light by darkening the chamber, or if the patient is allowed to be up and out, dark protective glasses or a shade, such as will fully protect the eyes, are to be worn. A bandage is rarely necessary. The diet will vary with the con- dition of the patient and is usually low, and all stimulants should be interdicted. The pain, which is often very severe and prevents sleep, interferes with recovery and may be moderated by enveloping the affected side, or the whole head, in a layer of cotton batting secured by a nightcap or bandage. The attacks of pain which commonly occur during the night, demand the application of hot compresses, either of bags of hot bran or salt, or of flannels wet with hot water until the pain is modified or relieved. Where atropine seems to exert but little effect on the condition, and the pain is not controlled, the continuous application of flannels wet with a hot decoction of hops and chamomile flowers will often have a soothing effect and render the absorption of the atropine or duboisia more speedy. Cold applications are rarely indicated, except in the first stage of iritis following injuries or operations, when they may be prophylactic, but after the condition has become one of active inflammation, they should not be used. If the disease assumes a chronic form, or even if it be acute and obstinately resists all treatment, or whenever there is a marked increase of the tension of the eye- ball, an iridectomy should be made, as this may shorten the attack. The incision should be made with a keratome, just behind the margin of the cornea and the segment of the iria removed close to its outer attachment. The iridectomy should 276 DISEASES AND INJURIES OF THE EYE. be made upward, so as to be concealed by the upper lid. If the adhesion of the iris to the lens is complete, or the pupil occluded, the immediate performance of an iridectomy is demanded as soon as the congestion has disappeared; the operation should in this case be made inward and a little down- ward, unless the pupil is clear, when it should be made upward. In these cases, it is often impossible to make a clear cut in the iris, owing to the impossibility of drawing the iris out, but the tissue tears easily and sufficient can generally be removed to gain a fair pupil. If the operation is too long deferred, the lens becomes cataractous and other changes in the tissues give but little chance of any improvement. REMEDIES. Under the following heads are indicated the remedies for the various forms of iritis. Aconite. In the first stage of an attack which appears after injuries to the iris. In other varieties arising from exposure to cold in which the inflammation appears sthenic from the inception of the attack. Arnica. Recommended for iritis arising from rheumatic and traumatic causes, but it is of doubtful utility. Asafceiida. In the plastic variety occurring particularly in females and from acquired syphilis. The pains are very char- acteristic and are described as of a throbbing, beating or burning character in the eye, and above, or around it, and lessened by rest and pressure, as of the face or side of the head in the pillow. Aurum mur. May be indicated in some cases of iritis- occurring in syphilitic subjects where the pains are described as seated deep in the bones about the eye, and of a tearing,, pressing, character and extend from above downward and from without inward. (The reverse of Asafcetida.) Belladonna. The choice between Aconite and Belladonna becomes necessary in the early stages of iritis, and will have to be made according to the concomitant symptoms. Under IRITIS REMEDIES. 277 Belladonna, there is usually marked photophobia and contrac- tion of the pupil. Bryonia. More useful in the serous form of iritis, but is also indicated in the plastic when occurring in rheumatic patients. There is soreness and aching in the eyeball and orbit, and sharp, shooting pains which extend through the head or face, or pressure under the orbit as if the eye would be forced out may be complained of. The eyeballs are often sensitive to the touch and on motion. China. Indicated in iritis occurring in debilitated subjects, and with a marked periodicity, or when arising from malarious causes. Clematis. This remedy is to be strongly recommended for the various forms of iritis when accompanied by little pain and great sensitiveness to cold air. It has been claimed to have a marked absorbent action upon the synechiae, but I have never been able to satisfy myself of its efficacy. Oelsemium. The most valuable remedy for the serous variety. The special eye symptoms in this variety of inflam- mation are not marked. Hepar sulphur. Serviceable in any variety of iritis, and particulary indicated in the suppurative form with accom- panying hypopyon. The pains are usually throbbing and intense, with great sensitiveness of the eye to touch. Warm applications seem particularly pleasant. Kali iod. Very useful in either the plastic or serous forms, particularly from syphilitic causes. Mercurius. The value of the various forms of Mercury in the treatment of iritis, is, I believe, very much overestimated, although it has long been considered purely homoeopathic. As a result of my own observations, I cannot agree with the homoeopathic authorities in regard to its frequent indication in iritis. I am fully convinced of its homoeopathicity in various conjunctival, cbrneal and retinal diseases, but in iritis no benefit is derived from its use, unless the lower triturations as the Ix, 2x and 3x are administered, and with such frequent repetition of the dose that an alterative effect is produced. 278 DISEASES AND INJURIES OF THE EYE. When administered in this way there is undoubtedly a marked effect produced upon the inflammation, in lessening the plastic exudation which is so marked, particularly in syphilitic cases. Its true homoeopathic sphere seems to be in those cases of iritis which approach the serous variety, or when the plastic nature of the exudation is not marked. Here Merc. cor. in the higher dilutions has given extremely satisfactory results. Nitric acid. A valuable remedy in the chronic and recur- rent varieties in syphilitic patients. The inflammatory symptoms are asthenic and the pain is often worse during the day than at night. jR/ms fox. In plastic and suppurative iritis occurring after operations upon the eyeball, or plastic inflammation associated with a rheumatic diathesis; the symptoms are intense and accompanied by chemosis and swelling, and spasmodic closure of the lids. Spigelia. Very suitable to cases of mild iritis where the inflammatory symptoms are not marked yet accompanied by severe neuralgic pains in and around the eye. Sulphur. In the suppurative variety with hypopyon, or in the chronic form. The symptoms are variable and the pre- scription must be made upon the concomitant conditions. Terebinth. A very important remedy for the plastic variety when presented in rheumatic patients, with the urinary symptoms characteristic of the remedy. Thuja. In plastic iritis in syphilitic subjects where condy- lomata are developed in the tissue of the iris. Among other remedies which may be useful in special cases are Pulsatilla, Cedron, Silicia, Cimicifuga and Prunus spinosa. IRITIS SEROSA. Serous iritis is a low form of inflammation in which the pupil is usually dilated. Minute flakes of lymph, and loosened epithelial cells from the surface of the iris, together with the serous "product of the inflammation, accumulate in the anterior chamber and give to the aqueous a turbid appearance. There IRITIS SEROSA TREATMENT, 279 is frequently also an extension of the inflammation to the membrane of Descemet (or clescemetitis), with proliferation of its endothelial cells, and the appearance upon the inner surface of the cornea of minute, whitish, opaque spots, which form a ring opposite the pupil, or have a triangular shape with the apex upward as already described under keratitis punctata. From the increase of the contents of the anterior chamber the iris and lens are pushed backwards and the anterior chamber appears much deepened and the intra-ocular tension is often considerably increased. There is much less tendency to adhesion of the iris to the lens than in other forms of iritis. CAUSES. It is liable to occur either as a result of inflam- mation of the deeper tissues, as the ciliary body and choroid, or of sympathetic inflammation, or from any cause which produces general debility, as prolonged lactation and constitu- tional syphilis. SYMPTOMS AND DIAGNOSIS. As already stated, there is usually a partial dilation of the pupil, the iris appears dull and is very slow in its response to light. The vision is poor from the cloudy condition of the aqueous; the pain is not marked, and the ciliary zone presents but slight injection. The eye, however, has an irritable appearance and flushes up easily under examination. Examination with focal illumination is often necessary to reveal the deposits of lymph on the surface of the cornea. There is no febrile reaction, which may be present in other forms of iritis, and there is so little general complaint that the affection may be neglected by the patient or overlooked by the physician. Occasionally, we may find it taking on a more active condition in cases which have previ- ously had iritis and resulting adhesions. The disease is apt to be obstinate and very protracted and the prognosis is often doubtful. TREATMENT. Atropine or duboisia are indicated if there is any tendency to adhesions, or if* the tension is not markedly increased. If there is much increase of tension the mydriatics will not be absorbed unless paracentesis is performed. The internal administration of such remedies as Gelseniium, 280 DISEASES AND INJURIES OF THE EYE. Arsen., Bryonia, Kali bi., Kali iod., will be indicated. Eserine solution externally if there are no adhesions will often cause a subsidence of the inflammation without operative measures, which consist in the performance of a large iridectomy in pro- tracted cases. IRITIS PLASTICA. Plastic inflammation of the iris is the most common form of iritis and has already been described under the general head of iritis. It is characterized by the exudation of coagulable lymph into the structure of the iris and gives it a swollen appearance and collects upon the surface narrowing or occlud- ing the pupil and gluing the posterior surface of the iris to the lens, so that adhesions occur over a greater or less extent of its surface, and on the administration of atropine the pupil does not dilate, or appears irregular as in Plate IV, Fig. 2. Adhesions occur early and there is a narrowing of the pupil- lary opening. In some cases of plastic iritis occurring in syphilitic patients one or more small gummy tumors upon the iris (Plate IV, Fig. 3) are observed. These condylomata may be reddish in color or yellowish and are pathoguomic of the syphilitic variety of iritis. These gummata grow rapidly and may destroy the eye, but usually respond readily to treatment and disappear and leave no trace. The vision rapidly deteriorates in plastic iritis from the clouding of the aqueous or the occlusion of the pupil. There is often marked febrile excitement, severe pain, photophobia and lachrymation. If the ciliary body becomes involved, the eyeball becomes sensitive to touch especially over the ciliary region. TREATMENT. Atropine must be used as early as possible and the adhesions torn or the dilatable portions of the iris withdrawn as far as possible. The atropine should be applied every two or three hours until the inflammatory symptoms subside. If the mydriatic seems to lose its effect or produces no effect upon the pupil or the tension is increased, a para- IRITIS SUPPURATIVA TREATMENT. 281 centesis of the cornea should be made, as the atropine will be more readily absorbed afterward and the operation itself will, if properly performed, have a marked influence in relieving the irritation of the eye ; occasionally better results are obtained from duboisia. Hot applications are to be applied to mitigate the pain, and if the case is at all severe, confinement to bed is necessary. It is well to envelop the head in a thick layer of cotton which should be worn constantly, and particularly at night, as it lessens the tendency to the nightly "attacks of pain by keep- ing up an equable temperature of the parts about the eye. The internal use of Asafcetida, Aurum, Bry., China, Clema- tis, Eserine, Merc, cor., Hepar s., Kali iocl., Khus tox., Sulphur or Terebinth, according to the indications already given, will produce rapid cures. IRITIS SUPPURATIVA. Purulent iritis may begin in the same manner as the plastic variety, but soon the \ us which has permeated the iris tissue and produced marked changes in its color, finds its way into the anterior chamber, which perhaps it half fills, forming hypopyon, as in Plate III, Fig. 3. Adhesions may form as in the plastic variety and it presents no special distinctive symp- toms from the latter. It is the most destructive form of iritic inflammation and is generally the result of injuries to the iris, ulcerated wounds of the cornea, or after operations on the eye, and is frequently the result of the extension of suppu- rative inflammation of the choroid. TREATMENT. Atropine must be used even when there seems to be no effect upon the pupil. Confinement to bed and the use of hot wet applications are necessary. As soon as hypo- pyon appears, unless the pus is absorbed and the condition improved by the remedies, a paraceiitesis should be made and the pus allowed to flow out through the opening, or if stringy and thick it may be necessary to extract it with a pair of fine iris forceps. The remedies most useful will be Hepar s., and Merc. cor. 282 DISEASES AND INJURIES OF THE EYE. IRITIS SPONGIOSA is a rare inflammation of the iris which is characterized by the filling of the anterior chamber with a sero-fibrinous exudation which has a delicate smoky or bluish appearance. The aqueous is turbid and the surface of the iris hidden by the exudation which may be soon absorbed or temporarily disappear on paracentesis of the cornea. It occurs after cataract extraction and in some cases of iritis occurring in aged people, but is a rare affection. In the only cases which have come under my notice, the condition rapidly cleared up under Kali bi. and Bsyonia. The inflammatory symptoms seemed to be only of low degree ; the pain, photophobia and other eye symptoms were not prominent. TUMORS OF THE IRIS. Morbid growths on the iris are very rare, but cases are presented occasionally which require treatment. SARCOMATA and MELANOMATA are very rare, and when occur- ring soon involve other tissues and require the removal of the eyeball. CYSTS are more common, although still very rare, and are developed in the iris tissue and gradually encroach upon the anterior chamber, or extend backward toward the ciliary body. They usually form very slowly and cause no disturbance until they increase considerably in size and then give rise to pain. Treatment. The best method of treatment consists in the excision of the portion of the iris which contains the cyst by an iridectomy. GRANULOMA are small nodular masses of granulation tissue which are sometimes seen after operations upon the iris. They require no treatment. CONGENITAL MALFORMATION& IRIDEREMIA or absence of the iris is of extremely rare occurrence and is accompanied by other congenital defects. COLOBOMA IRIDIS or cleft iris, occurs either in one eye or in both. The fissure is generally below but may be above. There is often a corresponding defect in the ehoroid. FUNCTIONAL DISEASES OF THE IRIS MYDRIASIS. 283 DISPLACED PUPIL. Sometimes the pupil retains its rounded form, but is placed close to the margin instead of opposite the centre of the cornea. The condition is termed Ectopia. PERSISTENT PUPILLARY MEJIBRANE. The remnants of the membrane which extend across the pupil in the foetus some- times persist after birth in the shape of fine threads extending across the pupil or upon the margin of the iris. They demand no operative interference. FUNCTIONAL DISEASES OF THE IRIS. Functional disturbances of the iris occur sympathetically with other diseases. In certain diseases, as apoplexy, there may be first a dilatation of the pupil followed by its contrac- tion during the stage of reaction. In meningitis, however, the pupil is contracted in the first stage, while as the disease advances the pupil becomes dilated. In attacks of hysteria the pupil is first contracted and becomes dilated later. In spinal sclerosis, there is immobility of the pupil followed by wide dilation. Mydriasis is a persistent dilation of the pupil and is readily diagnosed from the fact that the pupil does not contract on exposure to light. It is often associated with paralysis of the accommodation. Mydriasis is commonly confined to one eye but both may be affected. The dilation may be partial or complete. The dilation of the pupil results from paralysis of the branch of the third nerve which supplies the circular or sphincter muscle of the iris. The same effect may be pro- duced by the irritation of the cervical branches of the sympa- thetic which are distributed to the dilator fibres. Large pupils occur in myopes because they do not use their accom- modation and also in persons who are much debilitated, or suffering from anseniia, but in these cases the pupil is not inactive nor is the dilatation as great as in mydriasis. 284 DISEASES AND INJURIES OF THE EYE, CAUSES. Mydriasis appears as the toxic effect of certain drugs as atropine, hornatropine, hyoscyamine, duboisia, da- turine, gelsemine and others. It is not infrequently a sequela of diphtheria and may precede or accompany other muscular paralyses from the same cause. Traumatic injuries, concussion of the brain, syphilis, meningitis, hydrocephalus, cerebral tumors, sudden checking of the perspiration, rheumatism, neurasthenia, exhaustion, intestinal irritation and loco-motor ataxia may all be exciting causes. TREATMENT. Those cases which respond to treatment are dependent upon diphtheritic or syphilitic causes. Here Gels., Bell., Physostig., Arg. nit., or Kali iod., will be among the indicated remedies. In other cases but little benefit is derived from treatment, unless the more serious affection can be relieved. When associated with paralysis of the accommodation and of the ocular muscles, the remedies suggested for their treatment may relieve the mydriasis. When occurring from the accidental instillation of atropine, it may be partially relieved by the use of pilocarpine or eserine externally. MYOSIS. Myosis or contraction of the pupil is the opposite of mydriasis and results from paralysis of the sympathetic, or irritation of the third nerve, and may accompany spasm of the accommodation. CAUSES. Contraction of the pupil occurs in poisoning from opium or its alkaloids, from instillations of eserine, pilocar- pine and some other drugs. It is sometimes traumatic in its origin, as from injuries to the cornea or from the presence of foreign bodies. When the contraction is reflex from irritation of the fifth nerve, it is sometimes associated with atrophy of the optic nerve from cranial causes. It may arise from an over-sensitive condition or hyperrestliesia of the retina and from growths which cause pressure upon the cervical sympa- MYOSIS OPERATIONS UPON THE IRIS. 285 thetic, and from lesions of the cervical portions of the spinal cord. TREATMENT. This must be directed to the cause of the disease. HIPPUS is a rare affection in which there is a rapid dilation and contraction of the pupil. In the only case I have seen it was congenital and associated with a clonic contraction of the levator superioris and affected the right eye only. The spasincdic condition became very prominent on any excite- ment of the child. IRIUODONESIS, or a tremulous condition of the iris, is dependent upon a fluid condition of the anterior part of the vitreous or from the loss of its natural support, the lens, and is seen after the extraction of the lens in its capsule for cata- ract, or when there is luxation of the lens into the vitreous. OPERATIONS UPON THE IRIS. , IRIDECTOMY. This operation, which was brought into prominence by Von Graefe, is the most frequent operation upon the iris, and has a most decided influence in checking some destructive processes in the eye when accompanied by intra-ocular tension, as in glaucoma, cyclitis, or irido-choroid- itis. It may be useful in chronic iritis especially when recurrent, or when there are extensive adhesions, and in some cases of keratitis, or, for the removal of foreign bodies in the anterior chamber or upon the iris or lens. It is also prelim- inary to cataract extraction, or is made for the formation of a new pupil in opacities of the cornea, or stationary opacities of the lens. In making an iridectomy the purposes for which it is done are to be considered. If it is for lessening the tension as in glaucomatous conditions of the eye, a large part of the iris is to be removed and the upper portion is to be selected in all cases where there is no contra-indication, as the upper lid then covers the deformity to a large extent. If it is preliminary to cataract extraction, it is to be made in the same direction as that of the incision for the removal of the lens. 286 DISEASES AND INJURIES OF THE EYE. When made for the purpose of improving the vision, the best situation is inward and downward if the corneal opacity and the other lesions will permit it; if not, then it should be made directly inward, downward or outward, as the condition may decide. The extent of the iris to be removed will depend FIG. 10U. upon the indications for the operation ; if made for therapeuti- cal purposes, as in glaucoma, a large portion should be excised, perhaps one-fourth or one-third of the iris; if for improvement of the vision, then a small fissure may be sufficient, perhaps not more than one or two lines or 2 to 4 mm. The location of FIG. 101. the incision will also depend upon the indications for the oper- ation ; if for therapeutic purposes, it will be made in the sclero- corneal junction, while for optical purposes within the cornea. The instruments necessary are a speculum, to separate the lids, a pair of fixation forceps, a lance-shaped keratome, straight or curved as in Figs. 100 and 101, or a linear cataract knife (Fig. 102), a pair of straight, or curved iris forceps (Fig. 103) and a pair of straight, or curved iris scissors (Figs. 104 and 105). If it is desired to make a very broad iridectoniy, or if the anterior chamber is shallow, a narrow cataract knife is more FIG 103. suitable than a lance-shaped keratome. When a small portion of the iris is to be removed, a small lance-shaped keratome answers the purpose better. The operation is performed in OPERATIONS UPON THE IRIS. 287 the following manner: An anaesthetic may be used or not according to the judgment of the surgeon. The patient is placed in a recumbent position and, if an anaesthetic is used, when the cornea is no longer sensible to the touch of the finger, a speculum with the blades closed is introduced between the lids and the latter widely separated. The eyeball is then steadied by seizing the conjunctiva with fixation forceps at a point close to the corneal margin and opposite the position of the intended incision. The forceps are held in the left hand while the operator takes the lance-shaped knife in the right hand. In making the incision the tough nature of the cornea must be remembered, and if the force applied to the knife is not proportioned to the resistance of the cornea, the knife may be suddenly pushed into the anterior chamber and the iris or FIG. 105. lens wounded. If the proper direction is not given to the knife, it may split the layers of the cornea and not enter the anterior chamber, an accident which may be disastrous. The point of the .knife is now directed towards the centre of the eyeball at the location of the incision, and gently passed through the cornea, when its direction is changed by depress- ing the handle until the blade of the knife is parallel to the 288 DISEASES AND INJURIES OF THE EYE. FIG. 106. surface of the iris, wlieii the incision is completed by turning the blade first to one side and then another, until the inner line of the incision is of the same length as the outer. The knife is then gently withdrawn and the anterior chamber is emptied by the aqueous finding an exit through the wound, and the iris and lens move forward. The fixation for- ceps are now removed and the iris forceps are then taken in the left hand and the scissors in the right, the forceps are introduced closed into the wound and then allowed to open, and the iris, as it floats between the blades, is seized and withdrawn, put slightly on the stretch, and with one, two, or three cuts of the scissors, the portion desired is removed. Blood may be effused into the anterior chamber and may be removed by slight pressure upon the scleral edge of the wound with a spatula, and the application of a bit of soft linen to the wound, but no considerable effort or pressure should be used as the blood will be speedily absorbed; no portion of the iris or small clot must be left in the wound. A few drops of boracic acid solution may be dropped into the eye to wash out any blood or secre- tion of the conjunctiva. A compress bandage is then applied and the patient placed in bed. In all cases where there has been no increased tension, a drop of atropine solution is put in at the next dressing. Fig. 106 shows the position of the wound when the iridectomy is made outward; Fig. 107 the with- drawal of the iris by the forceps and the application of the scissors which are applied close to the sclera before the cutting. Fig. 108 shows the appearance of the coloboma, or fissure of the iris, after the operation, the dotted lines showing the loca- OPERATIONS UPON THE IRIS. 289 tion of the wound when made within the sclera. When the anterior chamber is very shallow, as in glaucomatous conditions, the operative procedure is the same as before, except that a narrow cataract knife (Fig. 102) is used and the point of the knife introduced into the extreme limit of the anterior chamber, or about half a line, or 1 mm., or even more, behind the transparent edge of the cornea, and an incision made par- allel to the surface of the iris; the iris is well drawn out and cut off close to FIG. 108. its attachment with two or three strokes of the scissors. Fig. 109 shows the line of incision and the size of the coloboma when made in an upward direction. The eye is bandaged as before and tho dressing changed once a day, but no atropine used. The reaction following these opera- tions upon the iris is usually very slight if properly done, and no acci- dents have occurred. The internal administration of Aconite, Arnica or Calendula undoubtedly hastens the recovery and prevents possible in- flammatory action. IKIDOTOMY, or "Wecker's incision of the iris, is an operation which is sometimes required after the removal of the lens for cataract. The iris, from inflammation following extraction, becomes adherent to the lens capsule by the formation of a false membrane, or the pupil is occluded. The operation is performed as follows: An in- cision is made, usually at the upper part of the cornea, about one-fourth of an inch long by a keratome, the point being pushed obliquely downward through the pupil into the vitreous. Into the corneal wound, Wecker's scissors, or Lie- bold's (Fig. 110) are introduced closed. When the point reaches the opening in the pupil, the blades are allowed to 19 FIG. 109. FIG. 110. 290 DISEASES AND INJURIES OF THE EYE. open, and one is passed behind and the other in front of the iris, which is divided by a single cut. The iris, which has been upon the stretch, immediately separates and a slit pupil results. In some cases two cuts may be required and a some- what triangular-shaped pupil is made. Atropine is instilled, a bandage applied, and rest prescribed for three or four days. IRIDODESIS, or Critchett's operation, consists in making an opening in the cornea anterior to the scleral junction, drawing out the iris with a hook and tying a fine silk thread around the withdrawn iris, and leaving the latter to slough off. The pupil by this means is dragged opposite a portion of clear cornea. The operation, however, is liable to lead to cyclitis or sympathetic ophthalmia, and has been superseded by the operation of iridectorny. CORELYSIS is an operation" devised for the separation of the adhesions of the iris to the lens capsule. A small incision is made in the cornea and a blunt hook or toothless iris for- ceps introduced and the adhesions separated by traction; the danger of rupture of the capsule and contusion of the iris is great, hence the operation is not commonly performed. IRIDODIALYSIS. In opacities of the cornea where only a narrow rim of transparent tissue remains, instead of making an iridectomy, which would leave a hazy scar at the margin where the incision is made, an opening is made through the opaque portion, a pair of fine forceps introduced and the iris gently torn from its attachment beneath the transparent por- tion of the cornea, and a portion of the iris drawn out through the wound and cut off close to the surface. CHAPTER XIV. DISEASES OF THE CILIARY BODY. ANATOMY. The ciliary body consists of a plaited zone containing the ciliary process and the ciliary muscle, lying between *the iris and the ora serrata, and is a direct continuation of the choroid. It is made up of the ciliary processes, meridional folds of the choroid, some seventy to eighty in number, which rise gradu- ally from the ora serrata and are continued forward to the iris. These processes have the same structure as the choroid, except its capillary layer, and are covered by the retinal pigment. In the depressions formed by the plaits, fit corresponding projec- tions of the zouule of Zinn, a transparent membrane contin- uous with the envelope of the vitreous and which also forms the suspensory ligament of the leiis. The ciliary muscle occupies the anterior and more internal portion of the ciliary body between the ciliary process and the sclerotic, and consists of bundles of grayish, unstriped mus- cular fibres which take three different directions. The outer, neat the sclerotic, which form the thickest part of the muscle, arise from a tendinous ring on the inner side of the canal of Schlemm, take a meridional direction and are lost in the cho- roid; the middle fibres diverge in an oblique direction and form a circular plexus, while the third layer occupies the anterior and most internal portion of the ciliary body and is made up of separate circular bundles which form the sphincter, 291 292 DISEASES AND INJURIES OF THE EYE. or ring muscle of Muller. The ciliary muscle is supplied by a filament from the third nerve, which has been stated to have a separate origin in the brain, and is probably the exclusive agent in the production of accommodation. The ciliary body is firmly joined to the sclera at the sclero- corneal junction, more posteriorly it is loosely attached to the sclera by the supra-choroidea and is largely supplied with congeries of fine blood-vessels which also form two arterial circles, whose office is to afford nourishment for the crystalline lens and to secrete the aqueous humor. It is highly supplied with ciliary nerves derived from the long and short ciliary, which form a rich plexus with minute nerve ganglia in its tissue, while all the nerves which go to the iris pass through it. . DISEASES OF THE CILIARY BODY. The ciliary body, from its situation between the iris and choroid, and its direct connection with them through similarity of structure, is liable to participate in inflammation of these structures. In inflammation of the iris the ciliary body is likely to be affected by the extension of the inflammation back- ward, while if the ciliary body becomes the seat of inflam- mation the iris is almost sure to become inflamed. Since the nourishment of the lens and the anterior portion of the vitreous is mainly derived from the ciliary body, any diseased condition of the latter interferes at once with their proper nutrition, and changes occur, which may result in opacities or in a cataractous condition of the lens, or a fluid condition of the vitreous. The abundant nerve supply of the ciliary body, which brings it into such intimate relation with all important parts of the eye, renders any inflammation of the part likely to lead to serious complications and hence is of the utmost importance and exceedingly dangerous. It is impossible, except in very rare cases, to separate inflammations of the ciliary body from those of the iris, as it is impossible to- examine the condition with the ophthalmoscope and the inflam- CYCL1TISIRIDO CYCLITIS. 293 mation extends so rapidly to the iris that the diseased condition of the latter masks that of the former. CYCLITIS. SYMPTOMS AND DIAGNOSIS. Hypersemia and inflammation of the ciliary body is characterized by injection of the vessels of the ciliary zone, congestion of the conjunctiva, intense photo- phobia and lessened vision, without marked change in the iris beyond the hypenemic condition. There is exquisite tender- ness over some portion, or the whole, of the ciliary region when pressed upon through the closed lid. There are also .severe neuralgic pains which affect the whole eyeball and the side of the head, even extending down the neck. The anterior portion of the vitreous becomes clouded and examination with the ophthalmoscope is impossible. Tension may be doubtful, or, as the disease advances, becomes increased and atropine lias but little effect upon the iris or upon the paroxysms of pain. A suppurative stage may even be entered upon without a purulent inflammation of the iris occurring, and pus may appear behind the lens or in the anterior chamber. CAUSES. Low conditions of the system, suppressed menstru- ation, and slight or ill-treated attacks of iritis, seem to excite it It has been observed in children after typhoid or scarlet fever. It may also occur from syphilis, rheumatism and titrurna, ;iud be consequent upon diseases of the cornea. TREATMENT. Hot applications, moist or dry, according to the comfort of the patient, should be used and absolute rest of the eye during the attack of the inflammation and for a long period after recovery has taken place prescribed. The general treatment of the acute affection will be similar to that of iritis and atropine or duboisia are to be used as in iritis. Much attention must be given to the general health, and the diet made nutritious and generous if the patient is ill-nourished or in a feeble condition. The chief reliance must be placed upon the use of internal remedies, the general indications for which will be found amongst those which have been already 294: DISEASES AND INJURIES OF THE EYE. given under iritis. Among those remedies, Bell., Bry.. Gels., Hepar, Kali iod., Merc, cor., Merc, iod., Bhus or Silicia will be likely to be useful. ^ IRIDO CYCLITIS. SYMPTOMS AND DIAGNOSIS. Inflammations of the iris when extended to the ciliary body, exhibit either a serous, plastic, or purulent form; there is consequently exudation and swell- ing of the structures of both, with exudation into the posterior chamber and behind the lens. The vascularity and pain are greater than when the iris alone is affected, and there is sharp pain which causes the patient to suddenly shrink back when the ciliary region is touched through the closed lid by the finger. The vision becomes greatly impaired from the opacities in the vitreous and there is scarcely any dilation of the pupil when atropine is used. In the serous variety there is increased tension in the acute form, which in the chronic form is replaced by a soft condition of the eyeball which results iu atrophy of the globe, or Phthisis bulbi. The irU becomes discolored, often grayish and atrophied. In the plastic inflammation the iris becomes attached over the whole surface of the lens and dense whitish masses fill the posterior chamber, often extending up onto the posterior sur- face of the lens and into the vitreous. These masses of exudation in and upon the ciliary body contract, after a time, and draw the iris backward, deepening the anterior chamber, and bringing about changes in the ciliary body itself, the vitreous and also the lens. The suppurative condition rapidly involves the whole eye, producing panophihalmiiis with com- plete destruction of the eye. The period of congestion may be short and the pus in the anterior chamber noticed among the early symptoms. The prognosis is more grave than when the iris alone is implicated, as the changes in the vitreous, lens or choroid, which result, destroy vision. CAUSES. The causes are the same as those already given under cyclitis. TRAUMATIC CYCL1TISTHE CILIARY MUSCLE. 295 TKEATMENT. This does not differ from that of the various forms of iritis which may involve the ciliary body. TRAUMATIC CYCLITIS. The most frequent form of inflammation of the ciliary body is that arising from injuries of this structure, as wounds, or lacerations of the eyeball in the ciliary region ; wounds in this region being more dangerous than in any other part of the eye. The penetration of the ciliary body by small bodies of any description, or their lodgment in it, are very prone to excite a most destructive inflammation of the part and become a very common cause of sympathetic ophthalmia. The ciliary body, under these circumstances, becomes the seat of a plastic inflammation which rapidly disturbs the relation of the interior structures of the eye to eacli other. These masses of white exudation oftentimes extend out into the vitreous and onto the retina, becoming organized connective tissue, which, after a time, contracts and causes separation of the retina from the choroid, or even detachment of the ciliary body from the sclera. SYMPTOMS. The symptoms do not differ from those of cyclitis from other causes. TREATMENT. In the beginning cold applications should be made, as the attack may be aborted by their use. "Where the disease has become established, it is to be treated as indicated for cyclitis. Later, it may become necessary to remove the eyeball. If there is a foreign body within the ciliary body, or within the eyeball, and cyclitis is imminent, enucleation should be practised at once. FUNCTIONAL DISEASES OF THE CILIARY MUSCLE. PARALYSIS OF THE ACCOMMODATION. Cycloplegia, or paraly- sis of the ciliary muscle, which causes total loss of power of the accommodation, is usually associated with mydriasis from paralysis of the sphincter pupillcc, as both are supplied by 296 DISEASES AND INJURIES OF THE EYE. branches of the motor fibres of the ciliary ganglion. One eye alone is generally affected, though the paralysis may affect both. SYMPTOMS. The marked dilatation of the pupil, together with the loss of power of distinguishing near objects, indicates this condition. If vision is restored to its normal condition by a convex glass the diagnosis is then complete. Objects often appear smaller because they seem nearer than they really are. In myopes the disturbance may be very slight, but with hyperopes the distant vision may also be affected, so that vision is much lessened. CAUSES. The paralysis may arise from idiopathic, trau- matic, syphilitic and rheumatic causes affecting the third nerve, or result from the use of mydriatic drugs. When idiopathic the condition may have been excited by prolonged use of the eyes for near and fine objects. More or less com- plete paralysis may occur after diphtheria and is then usually accompanied by some paralysis of the soft pnlate, and without affection of the mobility of the eye. Blows upon the eye sometimes cause it. Syphilis and rheumatism are the more frequent causes, and the lesion may exist in the brain or in the course of the branches of the third nerve, in the orbit, or in the ciliary ganglion. Mydriatics affect the accommodation as well as cause dilatation of the pupil. Atropine and horna- tropine are more commonly used for the purpose of paralyzing the accommodation than the other mydriatics, and the former much more frequently than the latter. TREATMENT. The treatment must be directed to the cause, and, as already stated, the paralysis is often symptomatic of some deep-seated and serious affection, hence will require such remedies as may be adapted to this condition, as it is fre- quently associated with paralysis of the other ocular muscles. The treatment is the same as that already discussed for paraly- sis of the muscles. When uncomplicated, the use of such remedies as Causticuni, Arg. nit, Dubois., Physostig., Kali iod., Opium and Paris quad, may be beneficial. Faradization or galvanization is often of benefit in addition to the internal remedies. Eserine, or pilocarpine, locally is sometimes of benefit in stimulating the paralyzed muscle. DISEASES OF THE CILIARY MUSCLE REMEDIES. 297 PARESIS OF THE ACCOMMODATION, or Accommodative asthen- opia, is much more common than paralysis and is not accom- panied by any change in the mobility of the eyes. It is frequently associated with a potential weakness of the extrinsic muscles of the eyeball. SYMPTOMS. The external appearance of the eye may give no indication of the weakness of the accommodation. The eye may appear clear, the action of the extrinsic muscles good, the pupil normal, the ophthalmoscopic appearances negative, and the visual power perfect, but the effort at reading or doing fine work cannot be continued except for a very short time. A feeling of fatigue and tension comes on so that the eyes must be closed and rested for a few moments until they regain their power. Objects may become indistinct, the letters in reading blur, the eyes feel hot or painful, and an aching arises in the brow and severe frontal or occipital headache follows and, perhaps, nausea and vomiting, if the effort is continued or the attempt to read is made by a dull or artificial light. When the condition has existed for a time, conjunctival or retinal liyperaemia may result. CAUSES. The common causes of loss of tone of the ciliary muscles are refractive errors; these may be very slight and will require careful investigation. The agency of hyperopia in causing accommodative asthenopia has already been consid- ered. The weaker degrees of astigmatism are often the exciting causes. The paretic condition and the development of the asthenopic symptoms seem to depend greatly upon the degree of irritability of the nervous system of the individual. It is frequently the result of general weakness and follows acute diseases or occurs during the course of chronic constitu- tional diseases. If is a frequent accompaniment of general neurasthenia, or the affection of the ciliary muscle may occur subsequent to the improvement of the general tone. It is often a sequela of typhoid, and acute exanthematous fevers, or is associated with diseases of the uterus and digestive tract. TREATMENT. Glasses which correct any refractive error 298 DISEASES AND INJURIES OF THE EYE. that may be discovered must be prescribed, and attention given to the improvement of the general tone of the system. A good and generous diet is oftentimes necessary in these cases, as well as moderate and daily exercise. The galvanic current, with one pole upon the closed eyelids and the other upon the nape of the neck, is often a valuable adjuvant in the treatment. The methodical exercise of the eyes in reading, as directed for muscular astheuopia, will also be useful. In addi- tion to the indications for the remedies given under muscular asthenopia which is often associated with accommodative asthenopia, the following should be consulted. REMEDIES. Duboisia. Paresis of the ciliary muscle. The accommoda- tive effort can be sustained only momentarily and hyperaemia of the conjunctiva and lachrymation occur from attempted use of the eyes. Conium. The letters run together on reading and the effort brings on vertigo or headache. Burning pain, deep in the eye, may be complained of and the light is usually disagreeable or painful. Physosiigma. While more valuable in spasmodic affections of the ciliary muscle, it is also curative in some cases of paresis of the accommodation following diphtheria. Argentum nit. Paresis following diphtheria, or in hyperopes, and weakness of the accommodation after herpes frontalis. Lilium iig. Weakness of the accommodation which has been preceded by an irritable condition of the ciliary muscle. There is usually photophobia, burning, smarting and heat of the eyes after use, and general relief of the eye symptoms from the open air. Jaborandi. Alternate contraction and relaxation of the ciliary muscle associated with uterine disturbance or with refractive errors. The effort to read or use the eyes for near work frequently causes nausea and even vertigo. SPASM OF THE ACCOMMODATION CAUSES. 299 SPASM OF THE ACCOMMODATION. Tonic spasm of the ciliary muscle is not uncommon in liypermetropes, astigmatics and myopes and also occurs in normal eyes. It frequently compli- cates muscular astlienopia. The contraction of the muscle relaxes the suspensory ligament, so that the lens is constantly in a state of increased convexity and the function of accom- modation is interfered with and myopia simulated. SYMPTOMS AND DIAGNOSIS. Distant objects are only seen indistinctly, while near objects are clear; the latter are held closer to the eye than they should be and fatigue, pain, or headache follows. If these patients are 'examined with glasses, the distant vision is improved or made perfect by the use of concave glasses, but it will be noticed that, while a weak con- cave glass, ^^ or Jg, makes the distant vision perfect, they can only read No 1 at six or eight inches, when even a myope of much greater degree would read it at twelve inches. This should excite our suspicions and on an examination with the ophthalmoscope in the direct method, we shall find that the refraction is hyperopic, astigmatic, or even myopic ; the pupil is often much contracted in these cases though not infrequently appearing perfectly normal. The late Dr. AVoodyatt called the attention of the profession, some years ago, to the fact that in the spastic contraction of the ciliary muscle, astigmatism became apparent and was. undoubtedly due to an irregular action of certain sets of the meridional fibres which probably cause more or less tilting of the lens. I have repeatedly verified the statements then made by him in cases in my own practice, and have seen the same good results follow the administration of Lilium tig. and Physostigma in causing the disappearance of the apparent astigmatism. CAUSES. Spasm is of frequent occurrence in children who are hyperopic and results from the perpetual strain which is occasioned by such eyes. In older persons with hyperopic refraction, who are constantly using the eyes for near work or fine objects, the ciliary muscle gets into a state of tonic con- traction which cannot be relaxed at the will of the patient. 300 DISEASES AND INJURIES OF THE EYE. An emmetrope may induce the same condition by prolonged use of the eyes for near work. In myopes it is produced by an irritable condition of the eye or from the use of glasses which are unnecessarily strong. It also arises in connection with some retinal affections or is the accompaniment of chorea. TREATMENT. Complete rest of the eyes must be enforced, and the most effective treatment consists in giving the ciliary muscles rest by the daily use of atropine solution until there is a complete relaxation of the spasm, when the true condition of the refraction should be determined and the necessary .glasses worn constantly. In milder cases, rest of the eyes from near work and the use of such remedies as Physostigma, Jaborandi, Lilium tig., or Agaricus will relax the spasm to such a degree that the refractive anomaly can be determined and corrected. Physostigma. Particularly serviceable in relaxing the spasm occurring in myopic eyes; the book is brought closer to the eyes than formerly and use of the eyes soon becomes -uncomfortable or impossible. Twitching of the eyeball is often present. Jaborandi. More useful in spasm of the accommodation occurring in hyperopic, myopic or astigmatic patients. The vision seems to disappear temporarily when an attempt is made to look at fine objects. Moving objects, as the people or teams in the street, occasion headache, vertigo or nausea. Agaricus. Useful in spasm of the ciliary muscle when accompanied by spasmodic conditions of the lids or ocular muscles. Lilium tig. Spasm of the accommodation in light degrees of myopic astigmatism, when cylindric glasses are indicated and yet are not worn with comfort. It has a marked effect in relieving the asthenopic symptoms which accompany these cases of spasmodic action of the ciliary muscle. i CHAPTEE XV. SYMPATHETIC OPHTHALMIA. Under the general term sympathetic ophthalmia are included a large number of ocular lesions which arise in one eye from. [ ^disease or injury of the other. That there is a sympathy existing between the two eyes haa j long been recognized. It may be observed even in very slight "external affections, as when the presence of a foreign body upon the cornea or beneath the lid, or a slight attack of con- junctivitis in one eye, excites more or less "fellow suffering'* in the other. This, however, does not result in any severe diseased condi- tion of the sympathizing eye. When the injury is more severe or affects certain regions of the eye, or the inflamma- tion is more deep-seated, the other eye may take on a very severe inflammatory condition. The importance of sympathetic diseases, .both with reference to their easy recognition and proper treatment, can hardly be over-estimated since they may lead to an impairment of the functions of the eye or destruction of its delicate tissues and loss of sight. Sympathetic ophthalmia is commonly divided into a stage of sympathetic irritation, when there is only functional disturb- ance, and one of sympathetic inflammation, when a destructive inflammatory process follows. SYMPATHETIC IRRITATION is practically the prodromal stage of sympathetic inflammation, but it may also appear and not 301 302 DISEASES AND INJURIES OF THE EYE. lead to that dangerous condition of which it is commonly the forerunner. It is marked by a paresis of the accommodation which causes difficulty or impossibility of accommodation. Any attempt to use the eyes for near work is followed by lachrymation and congestion of the eyeball and general irritable appearance. There is commonly more or less photo- phobia and perhaps some contraction of the visual field, fi ashes of light or other phosphenes, and frequent and temporary failure of the vision. These symptoms disappear quickly on the removal of the exciting eye. SYMPATHETIC INFLAMMATION. The most frequent form of the lesions of the eye which are included under the general name of sympathetic ophthalmia is that of sympathetic iritis, or irido-cyclitis, yet among the many other ocular affections which are superinduced in the second eye after disease or injury of the first, are ciliary neuralgias, irritation and inflam- mation of the optic nerve and retina, inflammation of the conjunctiva, cornea, and choroid. Glaucoma and diseases of the vitreous and the lens have also been reported as arising from the transmitted disease tendency of the injured eye. The ciliary nerves, which are believed to be the important agents in the transmission of this sympathetic disturbance from one eye to the other, are derived from the ciliary gang- lion, a minute, flattened body about the size of a pin -head, situated in the posterior portion of the orbit between the optic nerve and the external rectus muscle, and which serves as a centre for the supply of nerves, motor, sensory, and sympa- thetic, to the eyeball. Its roots are derived from the fifth, the third, and the sympathetic nerves; while from its fore part proceed the ciliary nerves, some fifteen or twenty in number, which pierce the sclera anterior to the optic nerve entrance, and run forward between the sclera and choroid, after further subdi- vision, to the ciliary muscle in which they form a fine net-work from which the cornea, iris and ciliary body receive their nerve supply. The naso-ciliaris nerve which gives off the sensitive branch of the fifth to the ganglion also sends two or three small branches, the long ciliary nerves, direct to the sclera, SYMPATHETIC OPHTHALMIA. 303 which pierce it near the entrance of the short ciliary nerves and pass forward to the ciliary region in the same manner as the others. This bountiful nerve supply of the ciliary region, which is also thus brought in close connection with all other parts of the eye, renders any injury or disease of this region of the utmost importance to the practitioner from the fact of the danger of most serious complications which are always imminent. The channel of transmission of the inflammation from one eye to the other can not be said to be invariably the same. Becent researches seem to have settled the point that while the sympathetic invasion is in many cases justly attributed to the agency of the sensitive or sympathetic fibres of the ciliary nerves, yet other cases arise by way of the optic nerves, the blood-vessels or their nerves, and the lymph tracts. CAUSES. The most frequent causes of sympathetic inflam- mation are injuries, especially in the region of the ciliary body; irido-cyclitis ; foreign bodies in the eye; and surgical operations involving the iris or ciliary body. Displacements of foreign bodies which have been encysted, contraction of cicatrized tissue, bony deposits in the choroid, or the wearing of an artificial eye upon a shrunken stump may also awaken the dormant tendency to sympathetic inflammation. Wounds likely to contract during the process of healing, and irritating foreign bodies are much less dangerous when they occupy positions beyond the ciliary region. The danger of transmis- sion of the inflammation after the injury is generally greatest during the five or six weeks following the accident. Yet in one case I have seen the other eye affected on the twelfth day after injury. On the other hand years. may elapse before any trouble is noticed. In one case I have noted, thirty years had elapsed. There exists, then, no period when danger can be said to have disappeared, as after twenty-five or thirty years an eye has become destructive of its fellow. As a rule all eyes which have undergone a suppurative inflammation, as in panophthalmitis, are not likely to cause sympathetic trouble, owing to the destruction of the nerves which results from the suppurative process. 304 DISEASES AND INJURIES OF THE EYE. SYMPTOMS. Sympathetic inflammation may commence in- sidiously, or burst out suddenly without the slightest hint or warning having been conveyed either by fatigue or impair- ment of the accommodation or other symptoms as photophobia and ciliary injection. On the other hand we may have the symptoms of weakened accommodation, frequent and transitory failure of visioii, photophobia and lachrymation, and general complaint of fatigue of the eyes with inability to use them ; these symp- toms have already been spoken of as those of sympathetic irritation, which may exist for some time before the nerve destructive process follows, or they may be the immediate forerunners of the most dangerous form of sympathetic inflammation. Sympathetic ophthalmia usually assumes the form of a plastic inflammation of the iris and ciliary body, or iris and choroid. There is in -this inflammation a remarkable tendency of the iris through this plastic effusion to become adherent over the whole extent of the lens, causing complete posterior synechia, the iris becoming thus perfectly immobile, and the pupil frequently filled with the plastic exudation. The tension of the eyeball, which early in the attack was increased by choking up of the channels of exit at the corneal junction, now becomes lessened from the pressure of the exudation upon the blood-vessels causing their obliteration. The nutri- tion of the vitreous and lens are thus interfered with and partial or complete atrophy of the eyeball results. In some cases the sympathetic inflammation assumes the form of a serous irido-choroiditis, which is less dangerous than that already alluded to, but unfortunately it usually passes over into the more dangerous type of adhesive inflam- mation. The tension of the eyeball, which early in the disease may have been increased by pressure of the mass of exudation upon the canals of exit at the margin of the cornea, now becomes reduced owing to the obliteration of a consider- able number of vessels in the most vascular region of the choroid from the choking process resulting from the interpo- SYMPATHETIC OPHTHALMIA DIAGNOSIS. 305 sition of the exudation upon and around the vessels. The nutrition of the vitreous humor is disturbed and its trans- parency lost, while the crystalline lens becomes opaque, and partial or complete atrophy of the eyeball results. DIAGNOSIS. The early sympathetic phenonema in the more common form of inflammation, that of irido-cyclitis plastica are, intolerance of light, ciliary injection, and discoloration of the iris. The iris exhibits a marked tendency to become adherent to the greater part or whole extent of the lens, speedily bringing about complete posterior synechia. For a short time the pupil appears depressed, but soon from similar adhesions between the ciliary body and the sclerotic and a movement of contraction in the adherent portions, which depresses the edge of the lens, the anterior chamber becomes wider toward the periphery, while the pupil advances consid- erably nearer to the posterior surface of the cornea. If to this characteristic appearance be added an immovable and vascular iris, which, owing to the closure of the pupil by the plastic exudation forms an extended plane, the appearance will be so remarkable that, without any history of the case a diagnosis may at once be made. A further examination will doubtless disclose the exciting cause as existing in the other eye. PKOGNOSIS. In young persons the atrophy of the eyeball, resulting from obliteration of vessels in the choroid, may be only transitory and we may find that the cornea again attains its normal curvature. The neoplastic masses undergo such a degree of atrophy and the tissue of the iris becomes so thinned that we may have a fair pupil resulting, and the vitreous may clear up so that we are enabled to examine the fundus and find that the inflammatory process has extended to the choroid, retina, or even the optic nerve. This affords sufficient explana- tion of the reason why loss of vision persists in spite of the general improvement. A phthisical condition of the bulb or atrophy may result from the disturbance of its nutrition. TREATMENT. The principal object of all treatment should be to remove as speedily as possible the sympathetic irritation. 20 306 DISEASES AND INJURIES OF THE EYE. by enucleating the injured eye, as nothing is gained by its removal after the disease has become one of sympathetic inflammation. An eye which contains a foreign body or has received a serious wound of the ciliary region should be removed early, unless the patient is constantly under surveillance so that we may be able to remove the eye at the moment when symptoms of irritation of the other eye appear. When the sympathetic inflammation has involved an eye, no operative interference is of any value beyond that which may be necessary to relieve the pain, and the diseased condition is to be treated as already described for irido-cyclitis. When it takes other forms, as that of iritis-serosa, keratitis, conjunc- tivitis, retinitis or neuritis, the destruction of the eye is not so rapid and the removal of the eye even when the disease has become well marked may check it and the eye be not seriously injured. While it seems a serious matter to deprive a person of an eye, which may be neither sightless nor painful, yet the knowledge that it is a menace to its fellow and may sooner or later result in utter loss of vision of the other, should cause us to instruct our patient of the extreme danger and advise its removal. The danger then to be found in all cases of severe injury to the eyeball, is the possibility of loss of the remaining eye through the transmission of sympathetic ophthalmia. Wiien this inflammation is once established no benefit is derived from the removal of the injured eye, hence it should be avoided by the immediate enucleation when symptoms of sym- pathetic irritation appear. If the injured eye has already lost all vision other than mere perception of light, and contains a foreign body, or is sensitive, and there is a probability of chalky deposits in the lens, or deposits of bony tissue in the choroid, or if the atrophied ball is sensitive or has attacks of inflammation or pain, enucleation is imperative at once unless the patient is constantly under supervision so that it may be removed immediately upon tne appearance of any symptoms of sympathetic trouble. SYMPATHETIC OPHTHALMIA ENUCLEATIQN. 307 The operation of enucleation is accomplished by dividing the conjunctiva close to the cornea by curved scissors, after the patient has been etherized, and the speculum introduced. .The muscles are then raised upon the strabismus hook, divided close to the sclera, and then the scissors introduced following the convexity of the eyeball until the optic nerve is reached and divided; the ball is then held by the fingers or forceps, and the tissue carefully dissected until it is entirely free from the socket; the orbit is then sponged with cold water until the hemorrhage has ceased, a wad of absorbent cotton placed upon a bit of soft muslin over the closed lids, and a compress band- age applied for twelve hours, when it is removed and the orbit and lids kept wet by a decoction of calendula flowers. No pain or reaction follows in cases where the operation is care- fully performed, and the orbit is usually in condition to wear an artificial eye in from two to three weeks. To avoid the necessity of removal of the eye and the conse- quent use of an artificial one, the operations of opiico-ciliary ncuroiomy and neuredomy have been devised; the results, however, have not so far been sufficiently conclusive for us to advise it as promising the advantages claimed for it. In the three cases in which I have made this operation, the results have not been satisfactory. It is only applicable to those cases in which there is no foreign body, deposit of bone, or growth in the eye, and when the eye itself presents no marked deform- ity. The dangers are from hemorrhage, or orbital cellulitis as a result of the operation, or the reunion of some of the nerves afterwards, and a recurrence of the symptoms of sym- pathetic irritation. The operation of neurotomy is performed by making a hori- zontal incision in the conjunctiva extending from the cornea to the outer canthus and the external rectus muscle divided at the insertion of its tendon after having secured the muscle by a thread ; the eyeball is then forcibly rotated towards the inner canthus, and on the introduction of scissors the optic nerve is divided and the eyeball further rotated inward until the ciliary nerves are brought into view and carefully severed at their 308 DISEASES AND INJURIES OF THE EYE. entrance into the sclera; having thus carefully divided all of them, the eyeball is rotated outward into position, the tendon of the external rectus muscle is united by a stitch, and the conjunctiva brought together by another suture, and the pres- sure bandage applied. The operation of neurectomy may be made at the inner can- thus without division of the muscle, by making an incision of the conjunctiva, between the internal and superior recti muscles with the blunt strabismus scissors, and separating the tissue until the optic nerve is reached when a strabismus hook is introduced and the optic nerve brought into view in the incis- ion and divided as far back as possible; the portion adherent to the sclera is then seized by the fixation forceps, and the ciliary nerves carefully divided and then the optic nerve is severed close to the sclera, the eyeball rotated into position, the wound in the conjunctiva closed with a suture and the bandage applied as in the former operation. The hemorrhage and prominence of the eyeball is less with this method of operation than the former and gives, I believe, the best results. The operation for enucleation is more easily performed and much safer in lessening the future dangers of any sympathetic trouble. USE OF ARTIFICIAL EYES. An artificial eye (Fig. Ill) is a hollow hemispherical shell of enamel which is so colored as to correspond with the iris and sclera of the other eye. They are made of various sizes and shapes and may need to have the edges notched to fit irregularities FIG. 111. i n special cases. After enucleation, the capsule of Tenon with the muscles attached is left to form a cushion upon which the artificial eye rests and thus partakes somewhat of the movements of the sound eye. When the contents of the globe are evacuated and the sclera left the motion of the artificial eye is better. If much of the contents of the orbit has been removed, they are of little use. An artificial eye may also be worn in some USE OF ARTIFICIAL EYES. 309 cases where the eye has been lost from disease or injury, provided that the cornea has been destroyed and that no foreign body is retained in the atrophied ball which should be neither sensitive nor painful. In children it is advisable to insert an artificial eye which is to be worn a few hours each day, in all cases where an eye has been removed or is much atrophied, as the arrest of development of the orbit and corresponding side of the face is materially lessened. When the conjunctiva has been extensively removed or destroyed, or the membrane atrophied from disease or presents cicatricial bands, the conjunctival sac becomes too small to retain an artificial eye. Occasionally the transplantation of portions of the conjunctiva of the rabbit, and the excision of the tendinous bands may enable us to insert an eye with good cosmetic effect. Care must be exercised in adapting the artificial eye to the requirements of individual cases, and the eye should never be so large as to prevent the closure of the eyelids over it. They should not be so large as to press upon the walls of the orbit, and should have a notch upon the upper and inner edge cor- responding to the supra-orbital nerve so as not to cause any irritation of that nerve from pressure. Under all circum- stances the artificial eye should be worn with perfect comfort, and should not be inserted for three or four weeks after removal of the eye, or until all inflammation and irritation have disappeared. When irritation or inflammation arise from their use, or the conjunctiva becomes granular, they must be laid aside and the condition relieved by treatment when they may be again worn. If there is much conjunctival discharge, the eye should be examined for any roughness or loss of smoothness on its surface or edges. An astringent collyrium should be applied to the conjunctival sac until the irritation is removed, and if the eye is found defective it should be replaced by a new one. To insert an artificial eye (proihesis oculi) the upper lid is raised by the fingers of one hand, and the upper edge of the eye which has been previously moistened is introduced beneath 310 DISEASES AND INJURIES OF THE EYE. it and the lid allowed to fall. The lower lid is now depressed until the lower edge of the shell is pushed into the lower palpebral cul-de-sac, when the eye finds its proper position. To remove it, the lower lid is everted and the thumb-nail or the head of a hair-pin is introduced under the lower edge of the shell which is slightly pulled forward when it at once falls into the hand held to receive it Should it fall u,pon a hard surface it will probably be broken. Those who wear artificial eyes soon acquire the knack of safe and easy removal. The eye should always be removed at night, washed gently in water and carefully dried, when it should be placed in a small box containing a layer of cotton until the following morning demands its use. After a longer or shorter time, a few months or a year or two, depending upon the condition of the conjunctiva, the enamel becomes worn and rough and excites a conjunctiva! irritation and the eye must be replaced by a new one. CHAPTEE XVL ANATOMY. - The crystalline lens is a transparent, solid body, of a double convex shape and rounded circumference. lis antero-posterior axis measures 5 mm., and its diameter from 8 to 9 mm. It is enclosed in a transparent elastic membrane, the lens capsule. The anterior surface of the lens is in contact with the iris, which rests slightly upon it towards the circumference. The posterior surface is more convex than the anterior and rests in the hollow formed for it in the vitreous. It is composed of flat, hexagonal, ribbon-like plates with serrated edges, which are held together by cement substance. These fibres are S- shaped and so arranged that the two ends are brought more or less close together, while the body of the fibre is directed towards the circumference of the lens. The fibres are arranged in lamellae, which overlap each other and form three triangular-shaped sectors with bases, towards the circumference and the points meeting at the center of the lens. During infant life the lens is more globular in shape, while in adult life the convexity is lessened, until in old age there is considerable flattening of the curvatures. 311 312 DISEASES AND INJURIES OF THE EYE. The lens does not present the same density tl-iro^ighout, the central portion, or nucleus, being more dense than the outer or cortical portions, which are soft and easily detached from the nucleus. In the adult lens, faint white lines or sutures are seen directed from the poles to the circumference ; these are usually three in number, but may be more, and diverge from each other like rays, those of the two surfaces alternating. These lines become apparent during life in some cases of cataract, and mark the place of intersection of the fibres in the lamellar segments. The lens capsule is a perfectly transparent, homogeneous and very elastic membrane, permeable to fluids, and is the medium through which the nutrition of the lens is carried on. Its anterior portion is about twice as thick as the posterior, the latter being very thin at the posterior pole. The circumfer- ence is strengthened by the added fibres of the suspensory ligament of the zonule of Zinn. ' Upon the inner surface of the anterior portion of the capsule is a layer of columnar endothe- lial cells which are the matrix cells from which the lens fibres are developed, and in adult life only one layer of cells exists; this undoubtedly bears a close relation to the nutrition of the lens fibres, which is probably carried on more actively from the aqueous chamber than the vitreous. The capsule is very elastic, and rapidly contracts and puckers up when torn. The zonule of Zinn, after it leaves the ciliary processes, splits up into fibres to be inserted into the anterior, and partly into the posterior surface of the capsule close to its periphery, in a peculiar zigzag manner. It forms with the hyaloid the so-called canal of Petit. The hardening process, which the Lens undergoes with the advancement of age, begins in the nucleus and advances towards the cortical substance, and this density when obliquely illuminated, gives an amber, or gray, hue to this portion of the lens. The function of the lens is to bring the rays, with the assistance of the other refracting media, to a focus upon the macula lutea of the retina, and hence any disturbance of its transparency affects the vision. DISEASES OF THE LENS CATARACT. 313 DISEASES OF THE LENS CATARACT. Cataract is the term applied to any opacity of the crystalline lens or its capsule, and is due to changes in the structure and composition of the lens fibres, or of the membrane inclosing the lens from proliferation of its endothelium or exudative deposits derived from neighboring tissues. The pathology of cataract varies with the causes which produce it, and consists of fatty degeneration or sclerosis of the lens fibres, or swelling of the lens fibres from the inhibition of fluid. VARIETIES. Cataracts may be divided into those where the opacity is situated in the lens, lenticular cataracts, or in the capsule, capsular cataracts. Lenticular cataracts are again classified according to the consistency of the lens into hard, soft, or mixed; according to condition into simple, complicated, stationary and progressive; according to the stage of the cataract into incipient, immature, ripe, hypermature and de- generated. CAUSES. The causes of cataract, excluding traumatic and capsular cataract, are still obscure and a matter of doubt and speculation. It appears most probable, as the lens depends for its nutrition upon the vitreous and aqueous humor, that any alteration or interference with its nutrition tends to render it opaque, and these morbid alterations in the condition of the vitreous or aqueous may depend upon local or constitutional causes. Among the local causes may be cited injuries to the eyeball, lens or its capsule, and inflammatory diseases of the interior portions of the eye. Of the more remote causes, rheumatic affections, syphilis, struma and sclerosis of the arterial coats. The changes in the lens may be induced by senile changes, alterations in the blood, or may arise from defective innervation. The causes, however, vary with the individual, and there is no single cause which will comprehend all cases of cataract. Dr. Burnett, of London, has called our attention to the effect of the excessive use of sugar, salt and calcareous waters as 314 DISEASES AND INJURIES OF THE EYE. productive of cataract, and to this I would add the saturation of the blood with stimulants and narcotics as undoubtedly interfering with the proper nutrition of the lens. SYMPTOMS. There is usually slowly developed dimness of sight, distant objects lose their clearness, and near objects must be held closer to the eye. The vision is improved by turning the back to the light, or shading the eyes with the hand. The patient thinks that a change of glasses is neces- sary but finds nothing that will improve the vision, or the vision may be temporarily improved by concave glasses owing to the swelling of the lens. He may also find the vision improved by tinted glasses which will dilate the pupil by lessening the amount of light admitted to the eye. The vision is usually better in a dim light, or in the evening, rather than during the day. Again, the gas jet or lamp flame may have a peculiar irradiation. This is not to be confounded with the rainbow colors seen in cases of glaucoma. There is rarely any pain, but specks before the eyes and phosphenes are not infrequently complained of. The objective symptoms consist in a grayish or whitish appearance of the pupil, which is usually contracted. The behavior of the pupil is of importance; if it is contracted and does not dilate rapidly under atropine it indicates an unfa- vorable prognosis for extraction of the lens. The field of vision in simple cataract is good and the patient quickly notices any variation in the light DIAGNOSIS. While the diagnosis of cataract is not attended with much difficulty, we must at the time of the examination consider the location, extent and character of the opacity and also whether it is simple or complicated. If the opacity is dense, it is readily recognized from the whitish or gray appearance of the pupil. Opacities of the cornea must not be confounded with cata- ract, and when oblique illumination is used, the lenticular opacity will be seen behind the pupil. If the pupil is con- tracted, or if the opacity lies more towards the periphery of the lens, it will be necessary to dilate the iris with atropine to LENTICULAR CATARACT. 315 fully define its character and extent. The smoky hue of the lens which comes from age and which is often associated with glaucoma, is not to be mistaken for true cataract; here the use of the ophthalmoscope, with a feeble illumination, will, when it is held ten or twelve inches from the eye, and the reflected light thrown somewhat obliquely from various points across the pupil, enable us to obtain a red reflex, and, at the same time, discover any real opacities which may be present, and which will appear black instead of gray when examined in this manner. LENTICULAR CATARACT. Cataracts affecting the lens fibres may be considered under four heads : the soft, zonu lar, cortical or mixed, and senile or hard. SOFT CATARACT. Soft cataract occurs under thirty years of age and is termed soft, because the nucleus up to that age has not acquired sufficient hardness to necessitate its consideration in the selec- tion of an operation for the removal of cataract. CAUSES. It may be congenital, but more commonly results from injury to the eyeball, as punctured wounds of the lens or rupture of its capsule from blows, and sudden compression of the globe. It also arises as the result of certain inflammatory diseases of the choroid or retina which involve the vitreous and thus impair the nutrition of the lens. DIAGNOSIS. It is hardly possible to mistake this form of cararact, as the pupil presents a bluish white or pearly appearance, and when the iris has been dilated with atropine the FIG - 112 - whole lens appears like a little sac filled with a milky substance, as in Fig. 112; now and then more opaque or chalky looking spots, or the sparkle of choles- terine crystals may be seen in it, as in FIG - n3 - Fig. 113. With the focal illumination or with the ophthalmo- scope the opacity is seen to involve the whole lens. 316 DISEASES AND INJURIES OF THE EYE. In some cases of traumatic cataract, masses of the lens sub- stance may be found extending into the anterior chamber as a gelatinous mass, or the whole lens may be swollen and press- ing forward upon the iris. PROGNOSIS. Congenital cataracts give good results as far as surgical procedure is concerned, but as they are often the result of arrest of development, the gain of sight is uncertain, because of the imperfect development of other portions of the eye. It sometimes happens that the disintegrated lens sub- stance is gradually absorbed and the shrunk and wrinkled opaque capsule, containing perhaps some chalky deposits, appears as an opaque membrane situated in the pupil slightly behind the iris, constituting in this case a capsular cataract. The prognosis of the traumatic variety will depend upon the extent and nature of the injury, and the presence or absence of a foreign body in the lens or eyeball. When the cataract is complicated by other diseases of the eye the pros- pect of vision depends upon the nature of the complication, which also increases the surgical dangers. TREATMENT. The treatment of these cases is purely surgi- cal, and two operations, those of discission and extraction, through an incision in the cornea, are used. In all cases of cataract occurring under thirty years of age the whole lens substance may be made to become absorbed by an operation which punctures the capsule and breaks up the lens fibres. In congenital cataract the operation should be made as soon after t)irth as possible, as the best results as to vision are obtained when the operation has not been delayed beyond a few months after the birth of the child. OPERATION OF DISCISSION. The operation for solution or absorption of the cataract (Fig. 114) is performed in the following manner. The pain from the operation is not suffi- cient to necessitate the use of an anaesthetic, except in young children. The pupil must be fully dilated with atropine and the patient placed in a recumbent position on an operating chair, or suitable sofa, before a good light. The eyelids are then separated by a speculum and a needle with a stop shoulder OPERATION OF DISCISSION. 317 FIG. 114. is introduced a lina Li front of the sclerotic margin of the cornea, on its inner side, passed over the edge of the dilated pupil until the point rests upon the lens ; a second needle is then introduced at the opposite point of the cornea until it also rests upon the centre of the anterior surface of the lens ; the capsule of the lens is then care- fully torn through and the needles by a gentle drilling motion made to slightly enter the cortical lens sub- stance. No pres- sure is to be made upon the lens, as it may be depressed into the vitreous, or injury to the ciliary body result from the tension of the zonule. The needles are now simultaneously withdrawn. The aqueous finds its way into the lens, which, swells up and undergoes absorption. This process requires several weeks and the operation will probably have to be re- peated at intervals of six or eight weeks until the whole lens is absorbed. The after treatment, if no complications occur, is very simple. The eye is bandaged, atropine instilled sufficiently often to keep the pupil fully dilated, and the patient kept quiet for a few days until all irritation resulting from the operation has disappeared. The pupil should be kept well dilated during the periods intervening between the succeeding operations, and the eyes protected from strong light. The dangers of the operation are, first, the swollen lens may cause an increased tension which may be rapidly destructive of vision. This arises from the too extensive rupture of the lens capsule, or from the effort to accomplish too much at the first operation, and probably from other causes which are not within the knowledge or control of the surgeon. If such a 318 DISEASES AND INJURIES OF THE EYE. complication should occur, an iridectomy must be made without delay, and the operation of linear extraction should be com- pleted. Secondly, the swollen lens, or portions of it which have escaped into the anterior chamber, may press upon the iris and set up iritis, or if the ciliary body has been interfered with by pressure upon the lens during the operation, an irido- cyclitis may arise. In such a case, the softened lens must be removed at once by linear extraction. Care must be taken not to rupture the posterior capsule with the needles, or the vitreous will mix with the lens substance and prevent its absorption. The danger of the operation is least in young children and when the whole lens substance is softened down. It is greatly increased if the margin of the lens is transparent. OPERATION FOB LINEAR EXTRACTION. (Fig. 115). This FIG. us. procedure is performed as follows: A needle operation, as just described, is usually performed first and may precede the extraction several days. If the lens is fluid this may be dis- pensed with. The preparation of the patient is the same as that for discission. An incision is made with a broad needle, or a keratome, about a line from the sclerotic margin of the cornea, and two and a half or three lines in breadth. A cystotome is then introduced into the anterior chamber, and the capsule ruptured in a line parallel to the incision in the cornea. Slight pressure upon the lower edge of the cornea with a curette may now be sufficient to cause the lens matter to flow out, or a narrow curette or spatula is introduced into ZONULAR CATARACT. 319 the wound (Fig. 116) and the lens substance allowed to flow out beside it. The after treatment consists of rest in bed, a bandage and the instillation of atropine, together with the controlling of any reaction which may arise, by Aconite, Arnica, or Calen- dula, and cold applications. THE OPERATION OF REMOVAL BY SUCTION is applicable only when the lens matter is in a fluid state and may be employed after the needle operation has rendered the lens very soft. The procedure is the same as for linear extraction, except that FIG. 116. after the capsule has been ruptured, the point of a suction instrument is introduced into the lens and the pulpy or fluid matter is drawn into the tube of the instrument, until the pupil is clear. Care must be exercised to prevent a portion of the iris from being drawn into the instrument. The advantages of these two methods over the simple needle operation is that time is saved, and the result of the operation, if successful, is at once more apparent and brilliant. While the needle operation is much slower in its results, the operation often requiring several repetitions, yet it is much the safer proceeding. After either of these operations, a portion of the opaque capsule may remain ; this must be treated at a later period by another needle operation as will be described under the oper- ations for capsular secondary cataract ZONULAR CATARACT. Zonular cataract is a variety of cataract in which a layer or _- zone of the cortical substance (Fig. 117) aarround- [fv\ ing the nucleus is opaque while the remaining por- \$J taons are perfectly transparent. At times, several FIG. 117. of these layers are affected and the nucleus also. 320 DISEASES AND INJURIES OF THE EYE. CAUSES. It is generally cougenital, but may be formed during the first few months of life, and may depend upon hereditary syphilis or infantile convulsions. SYMPTOMS. During the early period of the child's life, opacities of the lens may be overlooked, as defective vision may not be apparent until the child is about two years of age, when he begins to use the eyes for near objects. He may even then, owing to the natural largeness of the pupil, see tolerably well ; later, however, if the opacity encroaches upon the pupil the impaired vision is complained of. In many cases the vision is very defective and is frequently associated with, and may be the cause of, nystagmus. DIAGNOSIS. The opacity appears as a whitish-gray film, more commonly in the posterior cortical layers, and hence some distance behind the pupil. When the pupil is dilated with atropine and the lens examined by focal illumination (Fig. 118), the opacity will be found to encircle the nucleus, or the latter is itself opaque and whitish and with bundles of FIG. us. opaque lens fibres extending out from it into the clear remaining tissue. With the ophthalmoscope (Fig. 119) these opacities appear as dark rings or spots upon the red back-ground of the fundus. s" 10 - 119 - PROGNOSIS. With very few exceptions these opacities remain stationary, the lenticular opacity is well defined, small, and the circumference of the lens clear. If, however, in addition to the central or peripheral opacity there are also small dots or streaks in the cortical substance, the cataract is apt to become progressive. TREATMENT. If the vision is fair, or when the opacity is not central, patients occasionally derive considerable improve- ment from the use of atropine, which keeps the pupils dilated and the vision is made temporarily better while its action is kept up. If the periphery is clear, a small iridectomy may be made at the inner and lower portion of the iris with very satisfactory results. If the opacity is central and dense, or is- CORTICAL OR MIXED CATARACT. 321 progressive, the lens may be extracted, or removed by the more tedious process of discission. CORTICAL OR MIXED CATARACT. Cortical or mixed cataract is characterized by the appearance of opaque bundles of fibres, or striae, in the cortex /\ (Fig. 120), which commence at the circumference of the U|J lens and converge toward the centre. The striae may \!l appear in the anterior, but more often in the posterior no. 120. layers of the lens. These striae in young people are white, pearly, and broad, and progress rapidly. The term is also applied to that class of cases where the nucleus has become hard, as after forty years of age, when the cortical substance beco*mes opaque and the nucleus is involved later. CAUSES. When occurring under thirty-five or forty years of age, injuries of the eye and diseases of the interior struc- tures by interfering with the nutrition of the lens are the exciting causes. When appearing later it is due to mal- nutrition or senile changes. SYMPTOMS AND DIAGNOSIS. The vision is lessened accord- ing to the amount and density of the opacity. The striae are fully seen when the pupil is dilated, and when the cataract has fully formed. The degenerated corti- cal substance ex- no. 121. tends up to the no. 122. capsule, and the iris, when not dilated, is observed lying immediately upon the opaque lens. When examined by the ophthalmoscope the strire appear as dark lines as in Fig. 121, and when focal illumination is employed the streaks present a lightish appearance as in Fig. 122. TREATMENT. When the cataract is in an incipient stage, and when arising from constitutional enf eeblement, or diseased conditions of the interior tissues of the eye, the progress may be stayed by the use of such remedies as improve the general 21 322 DISEASES AND INJURIES OF THE EYE. condition of the blood and arrest the other local changes in the eye. When fully formed, and operative measures are desirable, the methods to be adopted for the removal of the cataract will depend upon the age of the patient; if under thirty, the operation for soft cataract will be indicated; if over this age, or after forty, tho nucleus has become so hardened that the operation to be described for senile cataract will be necessary. HARD OR SENILE CATARACT. This is the most frequent and important variety of cataract. It is called hard, because it occurs late in life when the nucleus has become dense and hard, and the loss of transparency is fa frequently situated in this portion of the lens (Fig. /} 123) ; it is called seuilo, from the fact that it is \J usually associated with other changes in the tissues FIG. i2a which result from advanced age. CAUSES. As persons advance in life senile changes take place in the lens by which its nucleus is rendered amber-col- ored, or smoky, and yet good sight is retained; this is not considered cataract, but these degenerative changes may advance still further and the process of osmosis becomes more difficult and the lens tissue opaque. The nutrition of the lens not being directly derived from blood-vessels, the condition of the lens from hardening of its texture is such that the circula- tion of the lymph through it is not sufficiently rapid to maintain the proper nourishment of the lens fibres, and the nucleus which is still further removed from the sources of supply, suffers and the immediate effect is loss of transparency, while later, there is a degeneration and a retrograde metamorphosis. Again, these changes may result from an interference with the circulation of the lymph currents in the vitreous, from local changes in the nutrient membranes of the eye, the choroid, or from an impoverished condition of the blood itself. We have in short, then, primarily, the lessened power of the lens to carry on its own nutritive processes, and secondly, an interfer- ence with its nutrition by causes not resident in the lens itself, HARD OR SENILE CATARACT. 323 and particularly the want of proper nutrient elements in the blood supply of the eyeball. Undoubtedly the saturation of the blood with certain matters, as urea, sugar, salt, calcareous matters, or the retention of waste material in it in patients who use alcohol, tea, or coffee to excess, is sufficient to account for the loss of transparency. SYMPTOMS. In senile cataract, the subjective symptom is commonly progressive dimness of sight, which induces fre- quent changes of glasses, in order to bring objects closer to the eye to obtain a larger retinal image. The vision is foggy, or the patient is annoyed by the distortion of the light or from shadows thrown upon the retina by irregularities in the opacity. Sometimes the patient finds his vision improved by concave glasses where previously convex glasses were worn; this is explained on the ground that, in the incipient stage of cataract, the lens becomes swollen and a mild form of myopia is temporarily acquired. There is rarely any pain or other disturbances complained of, in or about the eye. DIAGNOSIS. When the cataract is in an incipient stage some difficulty may be experienced in diagnosing the condi- tion, as the pupil may appear black and nothing may be observable but the amber hue of the nucleus which is seen by focal illumin- ation; dilating the pupil, however, will FIG. 124. probably reveal striae or grayish streaks extending from the periphery towards the pupil, which indicate changes in the cortical substance. With the ophthalmoscope, in this case, we may be still able to distinguish the details of the fundus fairly well, if the other media are clear. As the opacity increases, the diagnosis FIG. 125. becomes more easy, as the pupil takes on a yellowish, deep-seated haze, on which a shadow is cast by the iris on the side from which the light comes, as in Fig. 124. If now, the light is reflected into the eye with the ophthalmo- scopic mirror, the centre of the pupil appears dark, while around this dark blur a circular ring of red reflex will be ob- served, as in Fig. 125. 324 DISEASES AND INJURIES OF THE EYE. If the cortical changes are very marked the striae will appear white or grayish, as in Fig. 122, by focal illumination, and dark or black as in Fig. 121, when the ophthalmoscope is- used, and if the intervening substance is clear a red reflex with dark streaks is obtained and portions of the fundus possibly observed. If the cataract is far advanced and the opacity dense, no difficulty will be experienced in diagnosing the condition, as the pupil no longer appears dark but grayish, and the opacity will be discovered behind the pupillary space. Having diagnosed the presence of cataract we must also know the condition, whether unripe or immature, ripe or mature, or over-ripe, degenerated, or hyper-mature. An immature cataract is one in which the opacity is not complete, and with focal illumination a shadow will be thrown upon the lens by the iris, showing that there is still some cortical portion of the lens between the iris and nucleus which- has not become opaque and hard. The depth of this shadow will also enable us to judge of the amount of lens which still remains to be changed before the cataract becomes mature ; if the shadow is very narrow, there is less lens substance to be changed than when it is broad. A mature cataract is distinguished by complete opacity, the absence of any reflex from the interior of the eye when the mirror is used, and the edge of the iris appearing to lie directly upon the lens, no shadow being thrown on the cataract by the pupillary margin. "When a cataract has existed for years it degenerates and is termed hyper-mature. The outer layers of the cortical sub- stance become semi-fluid and a granular mass with fat globules and cholesterine crystals is observed while the hard, yellow nucleus is found partially below the pupil in the lens capsule, and may be seen to change its position with the movements of the head. This condition has been termed Morgagnian cataract. The capsule may also show degenerative changes, and, at times, deposits of calcareous matters are seen. Sometimes the lens appears of a dark brown color and there are no other HARD OR SENILE CATARACT. 325 opacities present ; the cataract is then called black or caiaracta nigra. In the examination of the cataract its size should also be noticed, as it has great significance, both as indicating the condition of the cataract and also having a bearing in regard to the operation. When the cataract is immature it is larger than when mature, as in the incipient stage the lens becomes more bulky from an increase of its watery elements, which are diminished as the cataract becomes ripe. Cataracts which form slowly are usually of less size than those which grow rapidly. A large cataract is usually present when the iris is pressed forward and the pupil reacts slowly, while if the surface of the iris is flat the cataract is smaller. PROGNOSIS. The prognosis of cataract includes the rapidity of its progress, its complications, its possible remedial relief, its removal by extraction and the subsequent prospective recovery of vision. Opacities of the lens which are developed in elderly persons increase until the whole lens substance becomes opaque, but the rate of progress varies greatly in individual cases, and depends very much upon the existence of the conditions which have primarily caused the opacity. As long as the nucleus alone is affected, the progress is very slow, and may remain stationary for a long time if the general nutrition of the eye is directly or indirectly improved. When the cortex becomes involved the progress towards complete opacity becomos more rapid, and the time consumed in the process will vary from a few months to several years. When the striae are broad the progress is commonly more rapid than when they are narrow. It may be possible, by the observance of proper hygienic measures and the use of remedies, to stop the increase of the striae and retain the vision of the patient for a long time. In general, the condition of the patient, as well as that of the eye, has much to do with the progress of the cataract. When the cataract is simple, that is when there is no dis- coverable lesion of the eye which produces it, the prognosis as regards the vision after its extraction is, other things being 326 DISEASES AND INJURIES OF THE EYE. equal, extremely favorable. When the cataract is the result of other changes in the eye, or is associated with active or past diseased conditions, it becomes a complicated cataract. These complications may consist of inflammatory or degen- erative changes in the cornea or iris, adhesion of the iris to the lens, a tremulous condition of the iris, a lessened condi- tion of the tension, the result of fluidity of the vitreous from extensive choroidal or vitreous disease, or the tension may be increased, as glaucoma is not infrequently productive of cataract. When the cataract is complicated, the prognosis becomes more difficult in proportion to the extent of the accompanying lesions. It is necessary to make a careful examination of the vision before prognosticating anything as regards the effect of the operation, as in simple cataract the patient should be able to recognize a lighted candle in a dark room at twenty feet or more with ease, and also be able to indicate its position when ten feet distant and held in various positions of the field. If complications exist, the quick perception of the light will be lost and portions of the field be absent, indicating retinal detachment, or the field be much contracted, the result of glau- coma or atrophy of the optic nerve. If, then, the vision is thus affected or the light perception lost, the operation for the removal of the cataract is not to be undertaken, as no chance of improving vision remains. In addition to the indications already given for a favorable prognosis in cataract extraction, we should have the cataract ripe and a pupil which responds promptly to the instillation of atropine and the patient tract- able and in as good a condition as possible as regards the general health. The amount of vision attainable is dependent upon the skill of the operator, the circumstances surrounding both patient and surgeon at the time of the operation, and the care and attention given the case after the extraction. A certain percentage of cases are necessarily failures. That is, the vision is only quantitative or is entirely lost, while in the best results the patient should be able to read No. C at ten feet or have vision ^. All degrees of vision attainable HARD CATARACT TREATMENT. 327 between these two results are termed partial successes. The probable chances of a good result can only be stated by the surgeon after a full examination of the cataract and the condi- O tion of the patient TREATMENT. When degenerative changes have occurred in the lens fibres no medical treatment will cause a return of their transparency and nothing remains to be done, beyond placing the eye and the patient in such a condition as will render the necessary surgical measures likely to give the patient vision. That lenticular opacity may occur and disap- pear spontaneously, or as the result of medical treatment, cannot be denied without impeaching the integrity and skill of otherwise undoubted authorities of both schools of medicine. There is no question but that in the incipient stage of cataract a great deal can be accomplished in retarding the progress of the opacity for an indefinite period of time, or even clear it up to such an extent as to make the vision entirely normal. The therapeutic means to be applied must be carefully individual- ized in each case, and in the selection of the homoeopathic remedy we must be guided, not only by the condition of the lens or the eye, but also by the general symptoms presented by the patient, inasmuch as the malnutrition of the eye is frequently only symptomatic of a general dyscrasia. In the absence of any brilliant results from the medical treatment of cataract, and from the fact that retrograde changes can only be accomplished by continued medication for months, too little attention has been given, the matter by those in our own school, who, if they would abandon the old notion of the utter impos- sibility of curing cataract by therapeutic means, and give their cases the close study necessary, would find that we had not yet reached the limits of the application of the law of similars. That there may be no doubt as to the results accomplished by the medication in cataract, the condition of the lens and the vision should be tested and recorded, and when the cataract is of slow progress, the vision should again be tested, after an interval of two or more weeks; if during this time there has been no change in the habits of the indi- 328 DISEASES AND INJURIES OF THE EYE. vidual and the vision is the same or has lessened, we are prepared to attempt the medical treatment of the cataract. If now, from time to time, we find an improvement in the vision with or without change in the appearance of the cataract, we must acknowledge that the probabilities are that the result has been obtained by the use of the remedies. If, during tho time the vision diminishes and the opacity increases, wo are ready to accord it a failure, then why not claim for tho better result that it followed from the exhibition of the remedy? Many cases of cataract which appear, are so far advanced, or the condition so complicated by other diseases, as to render any medical treatment useless for the purpose of improving vision; but the proper treatment of these cases will enable us during the period that must elapse before surgical measures can be adopted, to put both the eye and patient in a better condition, and thus achieve greater results from the operation, than would be possible otherwise. The remedies which have been employed with very favorable results in some cases; are Causticum, Sepia, Graph., Phos., Sulph., and Conium. Many others, as Chelid., Calc. carb., Lycop., Magnes. carb., Puls., Baryta carb., and Secale cor. have been reported as having removed lenticular cataract. Galvanism is of undoubted benefit in improving the nutrition of the eye. When the le.ns has become completely opaque and the cataract mature, the lens must be extracted before the vision can be improved. Various methods for the removal of- cataract are in vogue and these operations differ according to the condition of the eye and the nature of the cataract. As all cataracts are not favor- able for operations we must consider, before deciding upon the operation, the condition of the eye and also that of the patient. As regards the lens, the cataract which has just reached matu- rity is the most favorable for operation. If the cataract is immature, the cortex is not sufficiently hard or adherent to the nucleus, and there is great danger of the separation of the cortex from the nucleus and of the cortical substance remain- ing in the anterior chamber where it may excite serious inflam- OPERATIONS FOR SENILE CATARACT. 329 mation of the iris, or tend to the destruction of the eye. If the cataract is over-ripe there will bo difficulty in removing the semi-fluid substance with the nucleus, unless the lens is removed together with its capsule, and as these cases are frequently the result of inflammatory changes in the eye, they are often associated with degenerative changes which will render the result of the operation unfavorable. The eyeball tension should be normal, the pupil properly responsive to light, the anterior chamber of normal depth and the iris present a good appearance. If the iris is sluggish, or adherent to the lens capsule, dilated, or tremulous, the condi- tions are much less favorable. If the tension is increased, the field of vision contracted, or light perception deficient, the surgical operation can only be attempted when, in the judg- ment of the surgeon, a bare chance exists, and when the patient is advised of the great probability of failure. The general condition of the patient must be improved as far as possible by proper nourishment and exercise, to prepare him for the confinement necessarily attendant upon the operation. If the patient is suffering from some cachexia, with great depression of vitality, the operation is contra-indicated. If any conjunctival or lachrymal trouble exists, it must be cured before the operation can be undertaken. Whether one eye should be operated upon while the other is yet unaffected or fair vision retained, will depend upon the circumstances of individual cases. As a rule in senile cataract it is better not to do so, unless a favorable result is almost certain. "When both eyes are blind, it is better to operate upon one first, and not upon the other for at least two months afterwards. For if one alone is operated upon and the result is not satisfactory, the modification or change in the method of extraction may enable us to attain a good success in the second eye, which might have participated in the failure of the first had the oper- ation been performed upon both at the same time. OPERATIONS FOR SENILE CATARACT. Of the variety of operations performed for cataract extrac- tion those which require consideration here are the old flap 330 DISEASES AND INJURIES OF THE EYE. operation, the modified linear of Von Graefe, and those of Le Brun and Liebrich. The relation of the different incisions to the cornea will be understood by reference to Fig. 126 which shows that of the flap operation, FIG. 126. no. 127. no. 128. Fig. 127 that of Von Graefe, and Fig. 128 that of Le Brun above and Liebrich's below. The Flap Operation deserves but a passing notice as it has become obsolete. The extraction of the cataract was made through a large wound in the cornea, made by a Beer's knife, without interference with the pupil beyond that which was occasioned from the stretching of the iris during the passage of the lens over it. Tho results when the operation was successful were brilliant, but the danger of suppuration from so large a wound in the cornea has resulted in the abandon- ment of it for safer methods. The Reclination of Cataract has passed to deserved oblivion, from the fact that the displacement of the lens into the vitre- ous, where it acts as a foreign body, sooner or later destroys the eye, or causes sympathetic disturbance of the other. The operation consists in the introduction of a cataract needle about a line and a half from the cornea in the outer and lower portion of the sclera ; the needle is then pushed upward and forward until it rests upon the upper part of the lens which is then dislocated and pressed slightly downward until it rests in the vitreous. The immediate effect of the operation is brill- iant, but the after dangers are too great to allow of its perfor- mance except in very rare cases. I have never made the operation but once, and then in a patient who had but a few months to live, and to whom it gave the pleasure of vision while life lasted. MODIFIED LINEAR EXTRACTION. The modified linear extraction (Fig. 129) was first practised by Graefe in 1865. The danger of suppuration of the large corneal wound of the flap operation is avoided by making an MODIFIED LINEAR EXTRACTION. 331 incision slightly in the sclcra when a smaller incision will suffice for the escape of the lens. The bruising of the iris and its subsequent inflammation is largely avoided by the combi- nation of an iridectomy with the operation. The modified linear operation as now made by most operators differs in some minor particulars from that originally made by Graefe. The incision is made nearer to the cornea or in the sclero- corneal junction and increased in length. The danger of loss FIG. 129. of vitreous and the wounding of the ciliary processes and subsequent cyclitis is thus lessened. Improvements have also been made in the methods of opening the capsule. The operation is divided into four stages: first, the corneal incision; second, the iridectomy; third, the laceration of the capsule ; and fourth, the delivery of the lens. The patient should be put in as good a condition as possible prior to the operation and a good night's rest secured. The rectum should be emptied a few hours before the operation. An anaesthetic can be used or not according to the judg- ment of the operator and the ability of the patient to sustain the pain. In the majority of cases, it will be found advisable to use it, as the eye can then be perfectly controlled and all muscular contraction is avoided, while the shock of the opera- tion and the attendant nervous excitement is much lessened. 332 DISEASES AND INJURIES OF THE EYE. Its use is only contra-indicated by the struggling and its attendant congestion of the head, and the probability of vom- iting either during or after the operation. Yet I am inclined to think that ill results from such causes are rather rare, if the extraction has been properly performed and the eye well band- aged afterward. The iridectomy which forms the second stage of the opera- tion may be made at the time of the extraction, or some weeks previous, when it is termed a preliminary iridectomy; that it .Las its advantages is now conceded by all operators. As a rule, it is not necessary to give an anaesthetic for the perform- ance of the iridectomy, but from the behavior of your patient during this operation, you are able to determine the necessity of anaesthesia during the extraction. Again, there are further points to be gained by making a preliminary iridectomy. You are able to judge of the condition of the cornea and thus decide upon the proper incision for the individual case, of the irritability of the eye from operations, the ability of the patient to bear the confinement necessary after an operation, and finally of his tendency to that low grade of conjunctivitis which frequently retards recovery in this class of patients. If, on the other hand, the iridectomy is made at the time of the extraction, we have the large fresh wound of the iris corres- ponding to the line of the incision in the cornea, and in this the amount of injury to the eyeball is much increased, and the dangers from traumatism correspondingly greater. Moreover, the hemorrhage from the cut iris is oftentimes very annoying, and not infrequently complicates the operation by obscuring the lens to such an extent as to severely impede the operation. Again, during the process of removing the lens, the cut edges of the iris are more liable to be bruised, and we are apt to have a local, if not general, inflammation of the iris, which will cause adhesion to the lens capsule, or inflammation and consequent opacity of the capsule itself. These, then, are some of the advantages to be gained by separating the two operations. The objection against this method of procedure is the fact that patients coming from a MODIFIED LINEAR EXTRACTION. 333: distance must either remain during the interim separating the- operations, or return again for the second one. This is quite an obstacle to some patients, and where it cannot be overcome by the statement that the prospects of vision are much better from the division of the operation, it will be necessary to combine them. The iridectomy should be made upward, in the usual manner, with an angular keratome and about one-sixth of the iris removed. After the operation a bandage is applied, and the patient confined to bed. A few hours afterward, or the next morning, when the bandage is reapplied, atropine is to be- instilled to prevent adhesions of the iris. There is usually no. reaction, and in three or four days the patient is allowed to go- about as before. When the extraction is made by the modified linear method the following instruments are necessary: a speculum for hold- ing the lids widely apart, a pair of fixation forceps to steady the eyeball, a linear cataract knife, narrow and sharp, a pair of iris forceps and scissors, a cystotome and a lens scoop of hard rubber. The patient is placed in a recumbent position before a good light, ether administered and full anaesthesia produced before any attempt is made to proceed. The operator, if he uses the- FIG. 130. right hand, stands behind the head of the patient for the right eye, and at the left side for the left. The lids are then sepa- rated by the speculum, or the upper lid raised by an elevator or the finger of an assistant. The firsi stage of the operation is now begun. With the fixation forceps (Fig. 130), the operator seizes the conjunctiva below the cornea and makes his incision with the linear knife (Fig. 131), the point of which must be entered on the temporal side, exactly in the sclero-corneal junction and directed towards the centre of the 334 DISEASES AND INJURIES OF THE EYE. pupil; having arrived there, the point must be raised and carried across the anterior chamber, close in front of the iris, and made to emerge through the corneo-scleral ring at a point on a level with that of the entrance; with a slight sawing motion, the blade should now be made to cut its way out, keeping precisely in the corneo-scleral junction to the last, FIG. 131. when the edge should be turned to the front to cut through the conjunctiva, of which a short flap should be left attached to the cornea. At this stage, the cornea may collapse or blood may fill the anterior chamber. In the latter case, the lid must be dropped for a few moments and cold water applied; when the hemorrhage has ceased, the blood may be pressed out of the eye by gently wiping the wound with a bit of soft muslin, while the upper edge of the incision is slightly pressed back- ward by the hard rubber spoon (Fig. 132). The second stage in the operation is the iridectomy; this is intended to enable the lens to escape more easily, and also to prevent the prolapse of the iris in the wound, which would tend to prevent healing, or become a source of irritation to the eye. It is not necessary to remove a large portion of the membrane. The fixation forceps are now held by the assistant while the operator turns back the conjunctival flap with the closed iris forceps (Fig. 133), and if the iris presents itself at the centre of the wound, it is seized by the forceps, or if not, the forceps are introduced into the anterior chamber and the membrane caught near its pupillary margin, drawn out, MODIFIED LINEAR EXTRACTION. 335 and a piece about 5 mm. wide excised close to the sclerotic, with the iris scissors (Fig. 134). The third stage of the operation is the incision of the capsule; this is done by introducing either a Graefe (Fig. 135), or Knapp's cystotome into the anterior chamber, just behind the border of the iris, at the lower edge of the pupil, FIG. 134. and making a clean curved incision in the capsule parallel to the incision in the cornea. Various other methods of incising the capsule have been proposed, either by numerous cuts, or by a circular incision, which would remove the central portion of the capsule. The cystotome is made with a malleable shank so that it can be bent to suit the brow of either eye. The fourth stage : The edge of the lens may now be made to present its edge externally by pressing gently with the spoon at the lower margin of the cornea; as the lens advances into FIG. 135. the wound the spoon follows it up over the surface of the cornea and receives it as it escapes from the eye. If any cortex remains, it may generally be brought into the pupil by a gentle, circular, rubbing motion of the lids, and may be pushed out of the anterior chamber by pressure upon the lower lid, while the upper lid is slightly raised and with slight pres- sure depresses the upper lip of the wound. If the lens does not readily present itself in the wound the capsule should be again incised, or if the lens presents, but does not readily escape, the corneo-scleral wound should be again enlarged with the scissors. 336 DISEASES AND INJURIES OF THE EYE. It is at this period of the operation that there is the greatest danger of the escape of the vitreous; if it is small in amount, it is of no particular consequence, but a great loss may be followed by hemorrhage of the choroid or final shrinking of the ball. If the prolapse of the vitreous occurs before the escape of the lens, the latter should be removed by means of a wire loop (Fig. 136) ; afterwards a pressure bandage should be applied as quickly as possible. It happens in the majority of cases that, after the nucleus has escaped, a portion of the softened cortex remains. This should be removed by a gentle rotary motion of the finger upon the closed eyelid, or by pushing the lower lid upwards towards the wound. If this is not sufficient, gentle pressure FIG. 136. may be made upon the lower portion of the cornea by the hard rubber scoop, when the remaining portions will pass out. The wound is to be thoroughly cleared by the forceps of any prolapse of the iris, lens substance, or clot, and it should be observed whether there is an accurate approximation of the lips of the wound. The coujunctival sac should be cleansed with a weak boracic acid solution, and a compress bandage- applied to both eyes. The after treatment consists in the confinement of the patient to bed, in a dark room, and the dressings made by candle light. The patient should take that position in bed, upon the back or side, which may be most comfortable to him, and which can be maintained for at least ten hours without change. No- muscular effort whatever is to be made, and the food must be liquid so as to avoid chewing motions, but should be nutri- tious, as the strength of the patient needs sustaining. If all has gone well, there is no pain beyond a little smarting, or an occasional twinge from the accumulation of tears between the eyelids, which is relieved as the tears are felt to pass down the cheek. If possible, sleep should be obtained during the first night following the operation, as absolute quiet is of much LINEAR EXTRACTION CAPSULAR CATARACT. 337 greater value at this stage of the treatment than at any time later. The bandage may be reapplied eight or ten hours after the operation, if the eye is uncomfortable, but the eye should not be opened. If there is no discomfort, the bandage need not be disturbed for twenty-four hours. The nature of the discharge upon a bit of muslin covering the eye and the condi- tion of the lids will indicate the progress of the case. If there has been no pain and the secretion is of mucus and scanty, the indications are good. If there is pain, iritis is to be feared and atropine should be thoroughly used. If the lid becomes puffy and the discharge increases, the danger of suppuration of the wound is imminent, and it may be necessary to use hot fomentations of calendula lotion and stimulate the patient. If no complications arise after the second day, a drop of atropine solution is to be put into the eye night and morning when the dressings are changed. After a week or ten days, the patient may be allowed to sit up, J 7 and after this, the light should be gradually admitted to the room and the patient provided with a shade; usually, two or three weeks are required for the after treatment. In about a month or six weeks, if all irritation has disap- peared from the eye, glasses may be worn. The operations of Liebrich and Le Brun have FIG. 137. recently come into vogue. In both, the section lies in the cornea and the operation is performed with a somewhat broader linear knife and without an iridectomy. In Le Brim's, the incision is made in the upper portion of the cornea by entering the knife 2 mm. in the sclera and bringing it out at a point opposite and cutting directly out- ward, so that the incision ends in the cornea slightly above the pupil. The directions of the different incisions are given in Fig. 137, G showing the place where the Graefe original incision is made, S where it is now generally made, D the place of section of Liebrich when it is made in the upper section, L in the upper portion is the section of Le Brun, and L that of 22 338 DISEASES AND INJURIES OF THE EYE. Liebrich, when the incision is made in the lower section of the cornea. The modified Liebrich operation forms an easier method of extraction than that of the modified linear and the results are oftentimes better. A preliminary iridectomy should be made and the incision laid in the upper portion of the cornea; the point of a linear cataract knife broader than the Graefe is entered in the sclera about 1 mm. from its border at the upper third and carried directly across the anterior chamber and brought out at a corresponding point opposite. The incision is completed by passing with a slight curve through the cornea, so that the centre of the incision lies on the cornea midway between the-eclge of the pupil and "the periphery of the iris. The balance of the operation and the after treatment are the same as that described for the modified linear. Operations for the removal of the lens in its capsule have been devised and perfected by Paganstecher and others, and are suitable in some cases, as in the Morgagnian cataract. But these operations necessitate the introduction of a scoop or other instruments into the eye and are apt to be attended by extensive loss of vitreous or traction upon the ciliary body to the imminent danger of the eye. CAPSULAR CATARACT. Opacities of the lens capsule are rare, and result from the deposits of neoplastic masses upon its anterior surface, during an iritis, keratitis, or perforation of the cornea, forming anterior polar or pyramidal cataracts. When occurring upon ^ the posterior j \ portion of the \J capsule they are FIG. las. called posterior polar cataracts and are seldom visible without careful focal illumination when they present either a patchy or stellate appearance as in Fig. 138 and arise from inflammatory affec- tions of the deeper structures of the eye. APHAKIA LUXATIO LENTIS. 339 These capsular opacities are rarely amenable to treatment, "but may be stationary and interfere but slightly with vision if not extensive or central. SECONDARY OR MEMBRANEOUS CATARACT is a variety of capsular cataract which may follow cataract extraction. Opaci- ties form in the pupil some time, often months, after the removal of the lens. It may be filmy, like a delicate cobweb, which can only be detected by oblique illumination, or appear as a white membrane in the pupil. It is due to the proliferation of the cells of the capsular tissue, or results from iritic inflam- mation, and the iris is often adherent to it. The methods generally preferred are to tear an opening in the centre of the opacity by means of two needles introduced in the same manner as described for discission. The utmost gentleness must be exercised as the slightest traction upon the tough membrane is often sufficient to cause a cyclitis which may leave the eye in a worse condition than before. If the membrane is very tough the operation of iridotomy (see page 289) is often more practical. APHAKIA. Aphakia or the absence of the lens may, in rare cases, be a congenital condition. In the acquired form, it is the result of the removal of the lens, as after cataract operations. It requires a strong convex glass from + 4-| to + 4 for distant vision, depending upon the original refractive condition of the eye. As the power of accommodation is also lost with the removal of the lens, a stronger glass, usually + 3^ to + 3, will be required for near vision. Astigmatism is often present in these cases and its correction by combined sphero-cylindrical glasses oftentimes adds much to the vision of the patient. LUXA.TIO LENTIS. Dislocation of the lens may be congenital or result from injury. In these cases the iris is tremulous, and the edge of the lens may be seen in the pupil with the ophthalmoscope, 340 DISEASES AND INJURIES OF THE EYE. appearing as a dark curved line on the red background of the- fundus. If the displacement is congenital, the lens remains clear and operative interference is not indicated. The vision may sometimes be improved by the use of a proper convex glass. If the lens is loose and acts as a foreign body, it should be removed at once and inflammation averted. The incision is made as for cataract extraction and a wire or fenestrated scoop is introduced behind the lens and the lens removed in its cap- sule. The procedure may be facilitated by introducing a needle through the cornea and passed behind the lens so that the lens is held in position, while the scoop is introduced and the lens removed upon the scoop. When the lens is dislocated beneath the conjunctiva, it should not be disturbed until the sclero-corneal rupture is healed, when it is easily removed by an incision through the conjunctiva. CHAPTEE XVII. DISEASES OF THE VITKEOUS. ANATOMY. The vitreous body is a transparent, gelatinous mass occupy- ing the larger portion of the interior of the eye, about four- iifths, through which the light passes to reach the retina. It forms a support for the delicate structures of the retina, from which it is separable except about the optic nerve, entrance. Its anterior portion is hollowed for the lens and its capsule to which it is adherent. The vitreous is inclosed throughout, except in front, by a thin glassy membrane, the hyaloidea. It has no blocd-vessels in its structure in adult life, being dependent upon the vascular supply of the retina and choroid for its nutrition. Although presenting no structural elements in the fresh condition, when hardened it appears to be divided into concentric segments by minute prolongations of the hyaloidea, which also give out a radial striation around the optic nerve entrance. At the posterior surface of the lens certain cellular elements, which appear to be white blood corpuscles with amoeboid movements, are found; other cells of stellate shape have also been described by some authorities. Between the optic nerve disc and the posterior surface of the Ions is also a minute canal which in the foetus carries the hyaloid artery, derived from the central artery of the retina and which carries forward the nourishment to the lens during its development. In rare casos this artery persists in life. 811 DISEASES AND INJURIES OF THE EYE. The hyaloid membrane, at the anterior portion of the vitreous becomes firmer, is closely attached to the ciliary body, and is known as the zonule of Zinn, which presents a distinct fibrous structure. The fluid of the vitreous body consists of water containing some albuminate of soda and a little mucin. DISEASES OF THE VITREOUS. Disease of the vitreous occurs very rarely as a simple affec- tion, except as the result of senile degeneration, as it presents little evidence of organized structure, but as its nutrient elements are derived from the ciliary body, choroid and retina, it often participates in the inflammatory diseases of these tissues, and hence may also be the seat of acute or chronic inflammation which affects these structures. The morbid changes are more commonly those which result from variations in the density of its structure, and the presence of opacities, fixed or floating and of varying size. HYALITIS. Inflammation of the vitreous is characterized by the migra- tion of white blood corpuscles and their proliferation and these changes are often readily observed by the ophthalmo- scope, when the anterior portions of the vitreous are trans- parent. Hyalitis may be serous, plastic, or suppurative, according to the nature of the inflammatory exudation of the neighboring tissues which have involved the vitreous. CAUSES. In addition to the causes already enumerated, hyalitis occurs as the result of blows, wounds of the more posterior portions of the globe, and the penetration and lodg- ment of foreign bodies in the eya. SYMPTOMS. Any affection of the vitreous is known only by its effect in causing it to become turbid and fluid, thus impair- ing the vision. This turbidity results from the infiltration and proliferation of the cell elements which may also form opaque, membranous masses. These may be either floating OPACITIES OF THE VITREOUS. 34:3 or stationary, and if sufficiently large are readily seen with the opthalmoscope in the direct method, when the mirror is held a few inches from the eye and the patient directed to turn the eye rapidly in various directions, which gives the opacity motion and it will be discovered as it slowly floats past the area behind the pupil. TREATMENT. The treatment should be directed to the cause and for the indications of remedies useful, reference should be made to those given for the inflammatory diseases of the iris, ciliary body, and choroid. OPACITIES OF THE VITREOUS. The vitreous body is not absolutely transparent, for in most healthy eyes dark bodies may be seen on looking through a pin hole in a card, in a bright light, or at a white wall or cloud. These motes, or muscce volit antes appear in various forms floating about in the field of vision. They seem to the patient to consist of minute bead-like masses which are strung together in various shapes, or of delicate filaments having a webby appearance, and seem to ascend from the lower part of the field of vision and then fall down again, or when the attempt is made to watch them, they pass out of sight only to return when some near object is regarded. As they seem to retain the same relative distance from the visual axis, they are often annoying, but do not interfere with the distinctness of vision. These various appearances are due to the presence of minute cells in some portions of the vitreous, which intercept the light rays and cause shadows to be thrown upon the retina. The number of these cells is often greatly increased by over- work of the eyes at near objects, from derangement of the digestive organs, and in myopia. In the latter disease they become very annoying, from the fact that the shadows cast by them are often better defined than external objects. When they become very troublesome in nearsighted persons, they are an indication of the progressive condition of the myopia. It seems to be the result of immoderate tea drinking in many 344 DISEASES AND INJURIES OF THE EYE. cases, which produces digestive derangement and thus affects the eye secondarily. Such opacities as these are always too minute to be seen with the ophthalmoscope. Treatment. "When occurring in myopia, they may be greatly dissipated by the use of a properly adapted concave glass which by making the vision more distinct, tends to diminish their effect. When caused by too close work of the eyes, rest must be prescribed, and when connected with diges- tive troubles these must be corrected. There are none of our remedies which are specially indicated for this condition, but when used for the primary disease which is the exciting cause, they are frequently dispelled. When immoderate tea-drinking is probably the cause, abstinence should be practiced, or the consumption of tea much lessened and more food taken. OPACITIES OF THE VITKEOUS. The vitreous, which is of firmer consistency in its outer portion than in the more central parts, becomes in old age more liquid, from the fatty degener- ation of its elements. This condition, or synchisis, results also from inflammatory affections of the choroid and causes lessening of the tension of the eye, while the vitreous contains floating opacities which are observable both objectively and subjectively. In some cases of fluidity of the vitreous, called synchisis scintillans, numerous floating crystals of cholesterine are present, which, in an ophthalmoscopic examination, reflect the light and glitter like minute specks of gold, which rapidly move through the vitreous on motion of the eyeball. Opacities of the vitreous may vary in degree from a diffuse cloudiness to a dense mass which obstructs all view of. the optic disc or fundus. CAUSES. This condition may be due to any inflammatory condition, particularly syphilitic, of the interior structures, which causes an hyper - secretion of serous fluid into the vitreous chamber. As the primary disease subsides, the vitreous may gradually clear and become transparent, or opacities of greater or less extent remain. When these opacities are movable, or floating, they indicate a fluid condi- tion of the vitreous. OPACITIES OF THE VITREOUS. 345 SYMPTOMS. These opacities may interfere very seriously with the vision, if they lie in the visual axis, or may occasion no inconvenience when out of the line of vision and may be overlooked by the observer in an ordinary ophthalmoscopic examination. DIAGNOSIS. With the ophthalmoscope, in the direct method, these opacities, if not too minute or the Adtreous turbid, may be readily distinguished by using a proper correcting glass for the fundus when the opacity is situated near the retina, while if near the centre of the eye a convex 8 will be required, and when more anterior even a convex 4 or 5 will be necessary. A weak illumination should be used and the patient directed to move the eye rapidly in various ways so as to give direction to the floating body, which soon comes in view behind the pupil. TREATMENT. In general the continuation of the remedies which have been used for the productive cause of the opacities are still indicated; such remedies as Kali iod., Kali mur., Hepar, Gels., Phos., and Lachesis will prove more useful than others for this purpose. In cases of opacities from effusion into the vitreous, the patient should give up any occupation which tends to produce congestion of the eyes or head. In filmy opacities of the vitreous which seem to involve a considerable extent of it, improvement of vision may possibly be gained by tearing the filaments by the introduction of needles through the solera and thus separating the opacity in the line of vision. HEMORRHAGE INTO THE VITREOUS is caused by rupture of the vessels of the retina or choroid, usually the latter, and may arise spontaneously during inflammatory diseases of its tissues or from injuries to the globe. It is usually accompa- nied by localized detachment of the retina. A hemorrhagic opacity, unless very small, is not observable with the ophthal- moscope, as it more frequently fills the vitreous and prevents the light from entering the interior, and nothing but a dark reflex is obtainable; with oblique illumination a dark red appearance behind the pupil may be obtained. Sometimes the effused blood settles down as a coagulum in the bottom of the 346 DISEASES AND INJURIES OF THE EYE. eye. The vision is naturally greatly impaired and the patient complains of a red cloud before the eyes; this, together with the sudden onset of the blindness, which may occur within half an hour, will render the diagnosis easy. As already stated, it is often accompanied by detachment of the retina, and the patient must be examined according to the directions given in injuries of the vitreous in the chapter on Injuries of the Eye, to detect it and determine its extent, as this will affect the prognosis. The blood is absorbed more readily though gradually when it comes from the more anterior portions of tho choroid or ciliary body. Weeks, however, are required to cause a sufficient clearing up to allow of a partial return of vision. After hemorrhages, black threads or filaments remain either permanently, or for a long time, and may seriously interfere with vision, or when a coagulum forms tho resulting contrac- tion may result in detachment of the retina. Treatment. When due to injuries, ico compresses and rest in bed are necessary for the first two or three days and the administration of Arnica, Bell., Hamamelis and Lachesis will be useful. In hemorrhage arising from any cause it is better to confine the patient to bed for ten days or two weeks and bandage the eyes. CYSTICERCUS is a parasite which may also be found in other portions of the eye. While more common in Europe it occurs very rarely in this country; it is sometimes observed beneath the retina, or in the vitreous, and requires usually the enuclea- tion of the eye. It appears as a bluish-white cyst, which increases rapidly in size and induces inflammatory changes. PERSISTENT HYALOID ARTERY is a rare condition which results from the artery which is destined to supply nourish- ment to the lens during foetal life remaining in extra-uterine life. It appears as a. dark line extending from the posterior surface of the lens to the optic disc. Occasionally other blood vessels appear in the vitreous from the development of mem- branous masses or as prolongations of retinal vessels, and may disappear or become permanent. CHAPTEE XVIII. DISEASES OF THE CHOKOID ANATOMY. The choroid is essentially the nutrient membrane for the interior structures of the eyeball and consists of two layers of blood-vessels held in position by a stroma of connective tissue. It extends from the optic nerve entrance, around which it forms a ring, nearly to the sclero-corneal junction, where it ends in a series of folds or plaits, the ciliary processes, which, together with the ciliary muscle, form the ciliary body. Between the outer surface of the choroid and the solera, a lymph space is found in the large-meshed connective tissue which exists between these two membranes, except about the optic nerve entrance where they are closely united. This lymph space is held to be in direct communication with that of the capsule of Tenon and the other lymph spaces of the eyeball, and also with the different portions of the choroid. In the choroid four layers are described which are separated by endo- thelial cells which also envelop the blood-vessels. Of these layers, the most external has been termed the lamina supra-choroidea, a membranous layer similar to the lamina fusca of the solera, to which it is united by connective tissue meshes holding pigment cells, and to the whole choroid by endothelial cells, thus forming a lymph space. The next layer, the tunica vasculosa, or layer of large blood-vessels, pre- sents the major portion of the stroma of the choroid, which consists of striated fibre cells (6 Fig. 139) and pigment cells 347 348 DISEASES AND INJURIES OF THE EYE. choroid together. (a Fig. 139) of various forms uniting the elements of the The third layer, or chorio-capillaris, is con- tinuous with the meshes of the strorna with finer cells, and contains the capillary divisions of the arteries and veins of the tunica vasculosa. The remaining layer is the lamina vitrea or elastica, a struc- tureless, or finely fibrillated, transparent membrane covering the layer of capillary vessels and upon which rests the layer of hexagonal pigment cells of the retina. Through the stroma of the choroid and along its vessels are found smooth, un- striated muscular fibres which, in the human eye, are re- garded as rudimentary. The arteries of the choroid are derived from the anterior and long ciliary arteries which send recurrent branches, and from the short ciliary arteries which are lost in the capillary layer after numerous sub- divisions. The veins beginning as capillaries in the chorio-capillaris, take in the tunica Tasculosa a whorl-like form and uniting into large trunks, constitute the venae vorticosae (v Fig 140), which are four to six in number, and pass obliquely through the sclera in the equatorial region of the eye to empty into the ophthalmic vein; a- small portion of the blood from the anterior portion of the choroid being returned through the anterior ciliary veins. The nerves of the choroid are very numerous and are derived from the third, fifth and sympathetic through the long and short ciliary nerves and form in the choroid fine plexuses of nerves with many ganglionic cells. DISEASES OF THE CHOKOID. The choroid being the most vascular part of the eye, except the ciliary body, and being related by continuity of structure FIG. 140. DISEASES OF THE CHOROID. 349 with the ciliary body and through it with the iris, as we have already seen, is very prone to participate in the inflammatory action of those more anterior structures of the eye. As the outer layers of the retina and the greater portions of the vitreous derive their nourishment from the choroid, we find it intimately related to the various other portions of the globe, either directly or indirectly, and hence likely to be implicated in the diseases of these structures ; or, diseases of the choroid may result in changes in the retina, vitreous, lens or still more remote portions of the eyeball. According to the nature of the exudation, inflammation of the choroid is termed serous, plastic or purulent. As the choroid is a delicate tissue, consisting of a large number of blood-vessels and held together by a rather loose stroma, which rapidly becomes saturated with the products of inflam- mation when these are thrown out in large quantity, and as the sclera from its density offers considerable resistance to infiltration of its tissue, the copious exudation tends towards the interior of the eye, saturating and passing through the retina to the vitreous, from which it may pass forward and reach the aqueous. As the pigment layer of the retina lies upon the choroid, diseases of the latter 'cause changes in the pigment epithelium which may result in its absorption, prolif- eration or a crowding together of its cells in masses. CAUSES. Choroiditis is generally due to inherited or acquired syphilis, and appears usually at a more or less remote period after the primary and secondary stages have passed. It also results from injuries to the eye, occasionally arising idiopathically as the result of a low state of the system or as a sequel of severe constitutional diseases and after severe mental shock. Highly myopic eyes show a predisposition to choroiditis which may follow slight provocation. SYMPTOMS. Inflammation of the choroid, unlike diseases of its continuations, the iris and ciliary body, is seldom attended by external congestion, pain, heat or lachrymation. The vision may be either seriously or only slightly impaired, the visual defect depending upon the extent and nature of the choroidal 350 DISEASES AND INJURIES OF THE EYE. affection, r,3 well as upon the location of the lesion, and also upon the disturbances of the vitreous. DIAGNOSIS. As the subjective symptoms are not pathoguo- monic of the disease, the diagnosis rests almost wholly upon the ophthalmoscopic appearances. If the anterior portions of the eye are transparent and the vitreous clear, we shall be able to discover any changes in the choroid without difficulty. As the pigment layer of the retina commonly participates in the choroidal lesions, it is often very difficult to determine whether the choroid or the retina has been the seat of the primary affection, as the pigmentary changes are as frequently the result of retinitis or hemorrhage, as of choroidal trouble. The ophthalmoscopic changes usually met with are those which indicate atrophy of the choroid. These may be partial or complete, and occur in circumscribed spots of varying size. These spots are paler in color than the normal choroid or may ~be perfectly white, from complete atrophy of the choroid at the point of lesion, so that the underlying solera shines through. These patches may be surrounded by aggregations of the pigment epithelium which form black borders of vary- ing width and thickness, or the pigment itself is accumulated in spots, patches, or masses in the retina or choroid, without the atrophic appearances of the choroid. A few scattered and small spots of pigment on the choroid, or in the retina, often indicate former hemorrhages when there are no evidences of atrophy of the choroid. HYPER^EMIA. OF THE CHOROID. Acute congestion of the choroid occurs frequently in connection with other inflamma- tory diseases of the eye. Chronic congestion may appear independently, as in myopia, or from prolonged exposure to bright lights and great heat, as in men who are employed in rolling mills. It is almost impossible to demonstrate the condition with the opthalmoscope unless it exists in only one eye, or from the variations in tint of the fundus which may be observed to occur at different times in the same eye. Treatment. When the condition is inferred, the eye should be protected by dark glasses from all bright lights and Bell., Phos. or Puls. administered internally. DISEASES OF THE CHOROID. 351 ANEMIA OF THE CHOROID. In conditions of extreme anaemia the clioroid becomes of a pile and yellowish hue, but requires no special treatment beyond that indicated for the general anaemic condition. CHOROIDITIS SEROSA occurs rarely except as an extension of serous inflammation of the iris or ciliary body, the most frequent form being that of Irido-choroiditis (Plate IV, Fig. 4.) A thin, serous fluid is secreted, usually in large quantity, and percolates through the clioroid and retina into the vitreous, which becomes greater in quantity and clouded and the tension of the eyeball markedly increased. The anterior chamber appears more shallow and the bns and iris pushed forward. If the tension remains plus for any length of time, the retina and optic nerve suffer from compression and the vision is destroyed. When the process is acute, it is accompanied by photophobia, severe pain, fever and rapid diminution of the vision with marked increase of the tension, and has been termed acute inflammatory glaucoma, or glaucoma fulminans, from the suddenness of the attack. The condition is usually more chronic and there is, often, little pain, slight photophobia and only temporary increase of tension with variable vision. At times the vitreous clears up and an opthalmoscopic examination is possible, when the retina will appear hazy or grayish and the retinal vessels, particularly the veins, appear congested and tortuous. Causes. The disease occurs usually as a complication of serous iritis, or in eyes that show extensive posterior synechia, or occlusion or exclusion of the pupil, and in cases where the lens has been injured or dislocated into the vitreous. The more chronic condition occurs, not infrequently, in syphilitic patients with or without posterior synechia. Treatment. The cause must receive due consideration and the tension be carefully watched. Complete rest of the eyes must be enjoined and they should be protected from the light by smoke-tinted glasses, or in acute cases the eyes should be bandaged and the patient confined to bed. If there is much increase of tension, eserine solution, locally, may be of much 352 DISEASES AND INJURIES OF THE EYE. benefit, or it may be necessary to make a broad iridectomy to prevent destruction of the vision. Much may be expected from our remedies in this affection and the prompt use of Gelsemium, Bryonia, Phos., or Jaborandi will, when indi- cated, give brilliant results and prevent the necessity of opera- tive interference. CHOROIDITIS PLASTICA is characterized by the exudation into portions of the choroid of a plastic material consisting of a fibrinous substance with numerous round cells. These masses of exudation appear as round or oval masses in the stroma of the choroid, or extend into the retina. It may be either acute or chronic. When acute the iris is usually affected, and there is pain, ciliary injection and diminution of vision. The vitreous is at first cloudy, but as it becomes clear the ophthalmoscope reveals patches of whitish exudation of varying size which, from the fact that the retinal vessels are observed to pass over tli3in, are seen to be located in the choroid. The retina may be implicated and the vessel* partially hidden by the serous infiltration, and the optic papilla may also be swollen. In other cases as the disease progresses the pigment layer is disturbed and irregular black patches appear in the spots, or surround them as with a wall. In the majority of cases the condition is more chronic ai -I advice is sought because of the failing vision, and the diag- nosis depends entirely upon the ophthalmoscope. On exam- ination large patches of the choroid will be found to be atrophied, particularly in the posterior portion, or often all stages of the disease will be seen, from the primary deposits of exudation or of pigment in some portion of the fundus, while in others atrophic spots, with thinning of the retinal pigment and absorption of the choroidal stroma will appear, or the whole choroid will present an atrophic condition, and, if the retina. has been involved, the optic disc is atrophied and the retinal vessels are diminished and lessened in calibre while the fundus exhibits floating opacities which mark its fluidity. For clinical purposes two varieties are described, namely, choroiclitis disseminata and choroiditis areolaris; when the retina is implicated, the disease is termed chorio-retinitis. CHOROIDITIS DISSEMINATE. 853 FIG. 141. CHOROIDITIS DISSEMINATA (Fig. 141) is a variety of plastic choroiditis. In this variety, all of the patches or exu- dations are smaller than the area of the optic disc and are scattered through the otherwise healthy choroid, although several spots may coalesce and form large areas. All stages of the disease are frequently present in the eye at the same time, and the spots appear black, red, or white according as the pigment, choroidal stroma, or solera are observed. When the patches are white, there is always a border of pigment surrounding them. Both eyes are apt to be attacked but not to the same extent; frequently we find the disease existing only in one. Causes. The disease may be congenital or appear in young persons. When appearing in adults, it is often indicative of syphilis and has been termed syphilitic clioroidttis. The choroidal affection generally occurs from one to three years after the primary disease, whether it is inherited or acquired. It is, however, not necessarily an indication of syphilis, as it undoubtedly arises from other causes, as those mentioned under the general causes of choroiditis. Symptoms. The principal symptom is more or less loss of vision. Pain and injection of the eye are commonly absent. If only one eye is affected, the disease may be far advanced before aid is sought, but if the other eye becomes involved, the loss of vision is such as to cause immediate attention to the eyes. Disturbance of the retinal elements by the exudation in the choroid pressing upon or crowding the layer of rods and cones causes metamorpliopsia, micropsia, or megalopsia. If the choroidal inflammation affects the macula lutea, there is com- plete loss of central vision, while, if the peripheral portions 23 354 DISEASES AND INJURIES OF THE EYE. only are affected, the central vision may be but slightly impaired. Syphilitic choroiditis generally gives rise at an early date to opacities in the vitreous ; these may be of large size and readily seen, or so minute and numerous as to cause a general diffused haziness. Sometimes, in syphilitic cases, the whole f undus will be studded with minute dots of exudation in the choroid, the vision be much affected, the vitreous hazy, and after a time clear up and leave no evidence of the disease. Prognosis. The disease is very apt to be chronic in its course and may continue for months. In all cases the vision is permanently impaired, and the acuteness diminished accord- ing to the extent in which the macula lutea and the more central portions of the choroid are involved. Posterior polar cataract is sometimes developed in the advanced stage and serious opacities of the vitreous remain. Treatment. It is well to prescribe, in addition to the internal remedies, rest of the eyes and their protection from bright lights by the use of smoke-colored glasses. Confine- ment to bed, or a darkened room, is rarely necessary. Stimu- lants and the use of tobacco should be avoided in all cases. When the disease has passed into the stage of atrophy, nothing can be done beyond the prescription of slightly tinted glasses to relieve the glare arising from the reflection of the light from the sclera when the spots are large. The remedies which will be indicated are Kali iod., Merc, cor., Aurum mur., Bell., Phos., Nux vom., Kali mur., and Sulph. CHOKOIDITIS AEEOLARIS. This form of choroiditis is very similar to that just described and the pathological changes are the same, but in addition there is a hyperaemia of the optic disc, a haziness of the retina around the disc and exudation along the retinal vessels, particularly the veins. The patches of choroidal change are large or small, and in different por- tions of the fundus, as in the disseminate form. There is, however, sudden and frequent clouding of the vitreous and tendency to constant relapses. The disease is syphilitic and occurs in the later stages of the constitutional trouble. Treatment is the same as that for disseminate choroiditis. CHOROIDITIS SUPPURATIVAPANOPHTHALMITIS. 355 CHOROIDITIS SUPPURATIVA PANOPHTHALMITIS. Suppura- tive inflammation of the choroid is the most severe form of choroiditis, and is the result of injuries to the eye which cause suppurative inflammation of the iris and the whole uveal tract; as it generally involves the entire eye and even its appendages, the term panophthalmitis well describes it. Symptoms. The lids are swollen and red, the entire conjunc- tiva is infiltrated and chemosed and there may be a purulent secretion from the conjunctiva. The cornea is clouded and the iris discolored and adherent, and a yellow reflection appears behind the lens, or the aqueous is so clouded that the deeper portions of the eye cannot be examined. The orbital tissues become infiltrated and the eyeball is pressed forward, and may be immovable. The vision is rapidly lost and even perception of light may be absent. There is generally severe pain which lasts during the whole course of the disease. There is often febrile disturbance and vomiting. Again, the disease may appear with much milder symptoms, general injection of the globe, and the yellow reflex from the pus behind the lens being the first indications of this grave malady. Causes. Among the traumatic causes which may be men- tioned, are injuries of the iris, wounds or foreign bodies lodged within the eyeball, dislocation of the lens into the vitreous by accident, or from reclination of cataract, or after operations for the extraction of cataract. This disease may also result from pyemia, metastatic abscess, or embolism during the puerperal state, low fevers, mumps, caries of the temporal or cranial bones, or cerebro-spinal meningitis. Treatment. If the case is a mild one, atropine and hot com- presses together with the use of Phytolacca or Hepar s. may enable us to save the eyeball and perhaps some vision; when the condition has been excited by a swollen, cataractous lens or a foreign body, it should be removed, if possible. If the foreign body is beyond reach, it is better to enucleate the globe unless the inflammatory process is very violent, when it will be well to wait until the more severe symptoms have subsided, as enucleation in panophthalmitis is attended with considerable 356 DISEASES AND INJURIES OF THE EYE. difficulty and danger, as it may result fatally. The severe cases will require hot applications and an early incision through the anterior part of the eyeball, which will allow of the escape of the lens and some of the purulent vitreous and thus mitigate the pain. Attention to diet will be necessary, and if the condition of the patient requires it, a full allowance of nourishing food, and perhaps stimulants to sustain the strength, will be indicated. When the disease is well estab- lished but little can be done with remedies beyond preventing further complications, as the eyeball is almost certain to be destroyed. The remedies which may be indicated are Phytolacca, Rhus tox., Arsenicum, Hepar s., Merc., Silicia, or Sulphur, in the order given; the concomitant symptoms,, more than the special indications, deciding the choice. SCLEROTICO-CHOKOIDITIS POSTERIOR has been considered when speaking of myopia, and its ophthalmoscopic appearancea given. When progressive, the process is essentially the same as that of disseminate choroiditis. Other clinical forms of choroidal disease are observed, but of much less importance; of these, what are termed colloid excrescences merit notice. These consist of minute nodules, which appear like mustard seeds, and usually spring from i le lamina vitrea, the internal limiting layer of the choroid, and extend toward the retina, displacing and causing absorption of the retinal pigment, but do not interfere with the other layers of the retina, nor do they affect the choroidal stroma or interfere with vision. In rare cases, miliary tubercles are observed scattered through the choroid and are a constant accompaniment of acute tuberculosis and present a very similar appearance to colloid excrescences, although the masses are larger, being about one-third or one-half the diameter of the optic disc, and generally occur beneath the pigment layer and present a hemispherical shape, with the summit internal and reflecting the light SARCOMA or THE CHOROID is the only variety of tumor which has its origin in this tissue; when rich in pigment it is called melano-sarcoma. It occurs usually late in life, being rarely DETACHMENT OF THE CHOROID. 357 seen under thirty-five or forty. Defect of sight is often the only symptom in the early stages of the growth, but sooner or later the tension becomes increased, and pain and all the symptoms of acute or sub acute glaucoma appear. The tumor appears as a brownish rounded mass with a broad base and, as it grows, pushes the retina before it. Detachment of the retina around the tumor, either from hemorrhage or effusion, accompanies the growth, and in the early stages may render the diagnosis uncertain, but soon it will appear through the retina and will be distinguished by the irregular vessels upon its surface. As long as the tumor is confined to the interior of the eye, the growth may be very slow. The tumor, after filling the eye, will, if not checked by removal, soon appear as a fungous mass between the lids, or involve the tissues of the orbit and the brain. Treatment. The early removal of the tumor, while confined to the eyeball, is demanded, for if enucleation is performed before the optic nerve or the orbital tissues become involved, the prognosis is reasonably good, though the danger of secon- dary growths in the more distant organs, especially the liver, must be remembered. DETACHMENT OF THE CHOROID from the sclera may result from injury, the growth of tumors, or from collections of blood or serum behind it, and may be mistaken for a sarcomatous growth. In many cases the sudden effusion beneath the cho- roid results in separation of its tissue or rupture of the choroid, which allows of the escape of the fluid into the vit- reous. COLOBOMA OF THE CHOROID is a congenital absence of a portion of its tissue extending from the optic disc to the ciliary body, or it may be quite small and confined to the part around the nerve. The sclera is exposed, and with the ophthalmoscope the coloboma appears as an extensive atrophic spot in the choroid. It is almost always accompanied by a congenital cleft of the iris. ALBINISM is a congenital absence of the pigment layer of the retina and pigment stroma of the choroid, as well as of 358 DISEASES AND INJURIES OF THE EYE. the ciliary body and iris. The pupil appears pink from the light being transmitted through the sclera. Sight is defective and such patients suffer from photophobia and nystagmus. Slight relief is obtained by the use of dark glasses to moderate the light CHAPTER XIX. GLAUCOMA. The word glaucoma derived from the Greek glaucos, green was originally applied to cases of loss of vision accompa- nied by a greenish color of the pupil due to turbidity of the vitreous. Since the ophthalmoscope came into use, the term glaucoma, while only expressing an occasional condition which may be presented in the later stages of the diseased condition, is still retained but is now understood as indicating in the eye the presence of a certain group of symptoms, which are character- ized by an increased fluid tension of the globe. The definition which seems to cover and explain the group of symptoms to which the term is now restricted is this: " Glaucoma is the expression of a disturbance in the equilib- rium between secretion and excretion, characterized by an increase in the fluid contents of the eyeball." Glaucoma, then, consists in an increased tension of the globe, which leads to degenerative changes in the optic nerve, retina, choroid, and indeed of the whole of the interior struc- tures of the eye with loss of function. VARIETIES. Several divisions of the glaucomatous process are made according to the clinical manifestations of the disease ; practically, however, two varieties only need be con- sidered, viz: 1, acute or inflammatory; and 2, chronic or non- inflammatory. 360 DISEASES AND INJURIES OF THE EYE. ACUTE OR INFLAMMATORY GLAUCOMA. The term acute or inflammatory glaucoma is applied to that class of cases where there is an inflammation of certain struc- tures of the interior of the eyeball, associated with great congestion, consequent increase in the fluid secretion and accompanied by an interruption in the exit of the fluids from the eye. I CAUSES. The primary exciting cause is commonly an inflammation of the iris, or cornea, or an irido-choroiditis of a serous nature. It quite frequently follows injuries, as in punctured wounds of the cornea with rupture of the lens capsule, and consequent swelling of the lens substance which presses upon the iris and the latter interferes with the free exit of fluid at the angle of the iris into the canal of Schlemm. Again, the pressure of the lens upon the iris may cause an iritis which blocks up the channels for exit of the fluid and increases the tension. Again the increased tension may occur as a result of ulceration and perforation of the cornea when the iris has prolapsed into the opening. During or after iritic inflammations which have caused occlusion of the pupil or complete adhesion of the iris to the surface of the lens, or after cataract operations which have left a pupil closed by a false membrane. Tumors in, or even upon the eye, often give rise to attacks of glaucoma. "When occurring from these causes it is termed secondary or consecutive glaucoma. Acute inflammatory glaucoma may arise idiopathically, or occur as an acute exacerbation of the chronic form. SYMPTOMS AND DIAGNOSIS. Acute glaucoma comes on suddenly and the first symptoms observed are increased ten- sion and ciliary neuralgia. The globe is congested from sub-conjunctival injection, the anterior ciliary veins are promi- nent and turgid. The iris is sluggish in movement and the pupil dilated. The cornea appears dull, its epithelium perhaps punctated, and there is some loss of sensibility. The aqueous and vitreous are turbid and ophthalmoscopic examination impossible. The diagnosis of increased tension when the lids are swollen becomes difficult and often impossible. The ACUTE OR INFLAMMATORY GLAUCOMA. 361 Tision which before may have been good, now becomes markedly decreased. The diagnostic feature is the increased tension which is readily detected upon palpation. Acute glaucoma may be confounded with iritis, as the scleral congestion, dilated pupil, and shallow anterior cham- ber and periorbital neuralgia may be present in both. The injection together with the pain which may be referred to the whole side of the head, and the constitutional disturbance may also lead one to mistake the attack for one of cerebral trouble, but the close inspection of the eye and the testing of the vision will remove any doubt. The attack may arise without warning during the night and intense pain in the eye, forehead, or temple, be the first symptom complained of. Injection of the ocular conjunctiva rapidly appears and chemosis and swelling of the lids follow. The iris is discolored and dilated, and the anterior chamber shallow. The aqueous becomes turbid and the cornea hazy and no satisfactory inspection of the fundus can be made with the ophthalmoscope. The vision is rapidly impaired or wholly lost within a few hours. The condition may exist for a few hours and the symptoms rapidly disappear and the vision return. Again the attack may not subside for several days and the sight be entirely destroyed. Cases where the attack comes on suddenly and is accompanied by severe constitutional disturbance, with complete loss of vision from the start, have received the name of glaucoma fulminans. TREATMENT. "When the glaucomatous condition occurs after injury, prompt measures must bo used to relieve the fluid pressure, by paracentesis of the cornea, or when a swollen lens is the exciting cause it will be necessary to extract it. In other cases when the iris is not adherent to the lens tempo- rary relief may be obtained by the use of a solution of eserine to contract the pupil. Finally, it will be necessary to make an iridectomy if the tension is not lessened by other means. CHRONIC GLAUCOMA. In glaucoma simplex or chronic glaucoma we find, as a rule, two stages presented, the so-called premonitory and the con- firmed conditions. 362 DISEASES AND INJURIES OF THE EYE. The premonitory stage of glaucoma which may precede confirmed glaucoma by a period varying from a few weeks or months to several years, is characterized by the early appear- ance of, or the rapid increase of the existing, presbyopia, which requires repeated changes of glasses for near work. Halos or colored rings appear from time to time around the candle or artificial lights, and the field of vision is more or less contracted at times, or the vision is obscured and foggy, and the patient complains of the appearance of smoke before the eyes. The tension of the eyeball is more or less increased, the retina hypersemic, and the arteries are seen to pulsate when viewed by the ophthalmoscope, or pulsation is easily produced in them by light pressure of the finger upon the ball. These symptoms, except the presbyopia, which remains increased, are presented from time to time and last from a few moments to several hours, and then pass off and the vision again becomes normal. The periods of remission become shorter and shorter and after a few months or a year, very rarely longer, these prodromal attacks are succeeded by the confirmed condition. CAUSES. The causes of non-inflammatory or chronic glau- coma are as yet not fully known. It may follow upon one or more attacks of acute glaucoma. It is rarely observed under thirty years of age and occurs usually at or about the age of fifty years. Certain races (Jews) and particular families seem prone to the disease owing to a want of elasticity of the sclera, others (Arabs) enjoy immunity from it owing to remarkable suppleness of the membranes and the absence of fatty degenerations at any age. Sex seems to have no bearing upon the etiology of the disease, although women seem to be more liable to it than men. It occurs more frequently in hyperopic than in myopic eyes. Neuralgias of the fifth nerve, degenerative changes and hemorrhages in the retina, and adhesions of the iris and changes in the anterior portions of the eye which tend to keep up an irritable condition of the eye, are liable in elderly people to produce glaucoma. Among other exciting causes, mental anxiety and loss of sleep may be CHRONIC GLAUCOMA. 363 mentioned. The use of atropine seems sufficient to excite a glaucomatous condition in some eyes. The theories as to the local cause of the increased tension are various, and seem to satisfactorily explain the condition in individual cases and it is not probable that the glaucomatous condition is due to the same cause in all cases. Whatever the productive cause may be it is aided by the loss of distensi- bility which the sclera always undergoes with advancing age. The theory of Donders, that there is primarily a neurosis of the fifth nerve which occasions a hypersecretion of the intra- ocular fluids, well explains the glaucomatous symptoms in some cases. In the majority of cases the condition is undoubtedly due to the obstructions of the exits of the fluids from the eye. Recent pathological researches have shown such obstructions to exist from morbid changes near the attachment of the iris, ciliary muscle and canal of Schlemm which would impede the escape of fluid from the anterior chamber. Again the open- ings in the ligamentum pectinatum at the angle of the iris have been found filled with plastic exudation, or obliterated, and as the major portion of the fluid which has been used to nourish the interior structures of the eye, together with that secreted by the surface of the iris, passes through this porous structure to reach the canal of Schlemm, any interference with the normal removal of the fluid must result in increased tension. The increase of tension which may arise from these causes may be slight at first, but tends to interfere still more with the exit of fluid through the natural outlets and if it persists for any length of time produces changes in the deli- cate structures of the eye from pressure, or precipitates an acute inflammatory attack. Changes in the oblique channels in the sclera which give passage to the venae vorticosee, may also by obstructing the flow of venous blood, occasion an increase of tension in the posterior chamber which may rapidly involve that of the whole eye. The same condition may arise in cases of complete adhesion of the iris to the lens which prevents the passage of the nutritive fluids from the vitreous into the anterior chamber. 864 DISEASES AND INJURIES OF THE EYE. RESULTS OF PRESSURE. The immediate effect of increased iension of the eyeball is to lower the functional activity of the retina by retarding the circulation of the blood through it. When the retinal vessels can be seen in glaucoma the arteries sre narrowed and perhaps pulsating while the veins are tortu- ous and full. The contraction of the visual field occurs from the greater resistance which must be overcome by the circulation to reach the peripheral portions of the retina. If the fluid pressure continues for a time the optic nerve fibres suffer from stretch- ing and atrophy. The lamina cribrosa which forms the floor of the disc, being the weakest part of the ocular envelope, is pressed backward by the pressure of the increased fluid, the soft fibres of FIG. us. the optic nerve are pressed upon in the same manner and ultimately atrophy. The result is that the disc becomes not only atrophied, but depressed or excavated as in Fig. 142. This depression or excavation constitutes the glaucomaious cup which, when deep, presents steep or over- hanging edges. SYMPTOMS AND DIAGNOSIS. The chronic variety of glaucoma is distinguished from the acute form by its slower and more insidious progress. One eye alone may be affected but sooner or later the other becomes involved. As has already been stated it may follow upon one or more acute attacks, or exhibits the symptoms of the premonitory stage, the most important of which is the premature development or rapid increase of the presbyopia. The pain is less violent than in the acute attacks, and the conjunctival injection less marked or absent, but there is a marked turgidity of the anterior ciliary veins. The iris is sluggish in movement and the pupil dilated, often to its full extent. The cornea appears normal or may be dull and often more or less insensible to touch. The solera often presents an unnatural whiteness which makes the tortuous veins more prominent. The anterior chamber may be normal or shallow, -and the iris and lens pressed forward. The characteristic signs, however, are increased intra-ocular tension, excavation CHRONIC GLAUCOMA. 365 of the optic papilla and the regularity with which the pressure acts upon the retina, first limiting, and eventually destroying the field of vision. Increased tension, and sluggishness with slight or full dilata- tion of the pupil are more valuable as diagnostic signs than the excavation of the disc, as the latter may be present as a physiological condition. If, however, we have pressure-exca- vation the veins appear flattened and dilated at the edge of the excavation (as in Fig. 143 which shows the ophthahnoscopic appearance of the glaucomatous cupping), and arterial pulsa- tion will be produced by slight pressure of the finger upon the eyeball. The final confirmatory symptom, after palpation and the evidences of pressure upon the papilla, is the condition of the sensibility and circulation of the retina. Central vision is only slightly impaired at first, but the field of vision is found contracted, f ' ia>u31 the inner or nasal side suffering first, then the inferior and superior portions in turn, until only a narrow slit, widening outward, is left, and the sight may remain relatively good as long as the narrow end of the slit has not passed beyond the point of fixation. When there is concentric limitation of the field of vision, and the field of colors but little disturbed, the loss of vision is due to pressure- excavation and not to nerve atrophy. With this condition the patient is liable to acute inflammatory attacks which supervene upon such exciting causes as over-use of the eyes, mental emotions, over-indulgence in stimulants, or any cause which may increase the ocular congestion. Any one of these attacks may destroy the vision completely. When the glaucomatous condition has existed for a long time and there is permanent increased tension with total loss- of vision, degenerative changes result and the term absolute glaucoma is applied. The anterior chamber is shallow, the iris 366 DISEASES AND INJURIES OF THE EYE. widely dilated and atrophied, the lens transparent, or catarac- tous, and the pupil greenish. If the media are clear the ophthalmoscopic examination shows deep cupping of the nerve, absence of capillaries and lessening and disappearance of the arteries, and turgid veins. There is frequently constant or paroxysmal pains in and about the eye. DIFFERENTIAL DIAGNOSIS. The chronic form of glaucoma, being insidious in its approach, forms one of the most frequent causes of preveutible blindness, as it often goes undetected until the vision is to a great degree lost, and occurring as it does in patients of fifty years or more, it is too readily attributed to failure of vision from old age. The patient, however, finding there is no permanent improvement of vision from the frequent changes of spectacles which he has made, calls the attention of his medical attendant to his failing vision. Here the disease is frequently not recognized and more frequently mistaken for one of cataract, owing to a smoky appearance of the lens in the pupil, and the patient is advised to wait until the cataracts are mature when he can be operated upon with restoration of his vision. Reassured by the advice of his physician he watches his vision disappear from week to week until the sight in one or both eyes is reduced to simple perception of light, and is then sent to the oculist who in turn finds that the opportunity for the practice of Yon Graefe's brilliant discovery has passed, and the patient returns to his home hopelessly blind. Like cataract the disease is usually symmetrical and one eye may be affected a longer or shorter interval before the other. It occurs, as does senile cataract, generally in patients considerably past middle life, unless arising from injury or secondary to inflammatory changes in the structures of the eye, when we may have it appearing as does cataract at any age. Like cataract there may be the gradual failure of sight, this loss of vision being frequently attributed to senile changes. The reduction of central vision, however, is not as frequent as the impairment of the field of vision particularly on the nasal side. There are, not unfrequently, periods of blindness last- CHRONIC GLAUCOMA. 367 ing from a few minutes to a few hours, in cases of chronic glaucoma; these attacks may occur with little or no pain, the pain when present being referred to the eyebrow or forehead. With cataract the halo about the source of illumination may appear, rarely the colored fogs or rainbow tints as in some cases of glaucoma. With glaucoma we have a rapid increase of the existing presbyopia, that is the patient is no longer able to read at his usual distance with his glasses, but must hold his paper further from him, and changes his glasses for still stronger ones to keep pace with the increasing weakness of the ciliary muscle, until, finally, he finds even with the strongest glasses his vision is not improved. The cataract patient also, as he finds his vision failing, changes his glasses but gets no improvement, as the fault lies not in the paresis of the accommodation but in the loss of transparency of the crystalline lens. On exami- nation of the eye, we find in the glaucomatous case, a dilatation and sluggish condition of the pupil, whereas in cataract we have the pupil normal or contracted as in the aged. Again the cataract patient will tell you that his sight is better in the evening or by shading the eyes with the hand, while the vision in glaucoma is not improved in this way. We also notice that in glaucoma with the dilatation of the pupil, we have a shallow anterior chamber, the cornea flattened and frequently showing loss of sensibility. With cataract we have the anterior chamber, the curvature and sensation of the cornea normal. With glaucoma we may have a steamy or ground glass appearance of the cornea, which in cataract is transparent. With oblique illumination we discover at once the opacity of the lens in cataract, and in glaucoma we frequently find an apparent haziness of the lens, which is not necessarily the result of the disease, or if the intra-ocular tension 'has existed for some time, we may find cataract resulting from the glauco- matous condition. The ophthalmoscope shows in glaucoma hypersemia and cupping of the optic disc, and spontaneous or easily producible pulsation of the retinal arteries. In cataract 368 DISEASES AND INJURIES OF THE EYE. we are unable to obtain a view of the fundus as the view is arrested by the loss of transparency in the lens and not from turbidity of the vitreous. Finally, as has already been stated, with cataract we have no attendant pain, with glaucoma we may have pain or inflam- mation. With cataract the tension of the eyeball obtained by the sense of touch, gives no sensible resistance; in glaucoma, however, the sense of hardness becomes apparent at once if the tension is great, and in case of doubt, it should be com- pared with that of the normal eye. TREATMENT. In the prodromal stage the operation of iri- dectomy is not indicated, unless the patient is likely to be lost sight of, or when decided hardness of the globe remains after the attack has passed off. Every precaution should be taken to prevent cerebral and ocular congestion. Light smoke-col- ored protective glasses should be used. All excesses of either eating or drinking should be strictly enjoined. Sleep imme- diately after a full meal should be forbidden and the use of strong tea or coffee stopped. The eyes should not be exposed to bright lights, cold winds or dust. Any causes of ill-health should be carefully investigated and removed if possible, and the endeavor made to put the patient in a good condition. If the vision becomes impaired or the glaucomatous condition becomes confirmed, or inflammatory symptoms supervene an iridectomy should be made at once. For the chronic or confirmed glaucoma the only known remedy which seems at all beneficial is iridectomy. The dis- covery of Yon Graefe, that the removal of a large section of the iris was capable of lessening the intra-ocular tension and curing in many cases the glaucomatous condition, will ever cause his name to be held in the highest honor, for the means thus afforded of saving a great many eyes from absolute blindness. The operation of iridectomy, however, is not the only remedy we have for the condition, but it properly heads the list, and if prompt relief is not obtained from other measures no hesitancy should cause any delay in the perform- ance of the operation. CHRONIC GLAUCOMA. 369 Of homoeopathic remedies, Bell., Bry., Colocynth, Gels., Prunus, and Phosph., have been of undoubted benefit in the premonitory stage, and have a marked action in relieving the pains and periodical exacerbations. The local use of eserine solution diminishes the tension of some cases of glaucoma and in a few cases has proved useful. The severe pain which is present during exacerbations of the glaucoma may be somewhat mitigated by the use of hot moist applications to the eye and if the pain is intense it will be necessary to prescribe an opiate. Iridectomy cures glaucoma by the permanent reduction of the tension which follows the operation; the rationale of its action, however, is not yet understood, yet no doubt can be entertained of its curative properties and the delay, sometimes of only a few hours, to perform the operation when there is increased tension may produce irreparable blindness. In order that iridectomy may produce a lessening of the tension of the eyeball a large segment, at least a quarter or ev^en a third of the iris must be removed, .and it must be taken away quite up to its ciliary attachment, a result which is better attained by two or three sections with the scissors, than with only one clip as in an ordinary iridectomy. The incision should be made in the cornea close to the sclero-corneal junction and in a direction parallel to the plane of the iris. The modus operandi of the operation has already been given on page 287. The following rules are to be considered in deciding upon the necessity for the performance of an iridectomy in glaucoma. No iridectomy is to be performed in the premonitory stage of glaucoma as long as the field of vision is not contracted. When acute inflammatory symptoms appear in an eye which has exhibited increased tension an operation should be made without delay. When the chronic condition exhibits more or less inflamma- tory tendency the performance of an iridectomy affords the patient the only chance of saving his vision. There is a form of glaucoma which is marked by stony hardness of the eye- ball after a few hours with complete loss of vision and yet 24 370 DISEASES AND INJURIES OF THE EYE. without inflammation, the glaucoma maligna of Von Graefe, in which iridectomy is constantly followed by intra-ocular hemorrhage. Here it is not wise to make an iridectomy. Again the operation of iridectomy is contra-indicated in those cases of increased eyeball-tension which exhibit hemorrhages in the retina or choroid, the glaucoma hemorrhayica. The operation of iridectomy also seems to precipitate an attack of acute glaucoma in the other eye, but the cases which are likely to be followed by such disastrous results are not determinable before operating. Among the other measures which have been proposed and used for the relief of glaucoma are sclerotomy and myotomy, trephining the solera, and the insertion of a gold wire suture through the sclera. Of these the only one which has proved of value as a substitute for iridectomy is the operation of sclerotomy which is performed in the following manner, na. 144. The pupil is to be well contracted by the instil- lation of eserine and a linear cataract knife introduced on the temporal side one millimetre behind the sclero-corneal junc- tion, and three millimetres above the horizontal meridian. The point of the knife is carried slightly forwards, in front of the iris, pushed across and brought out at a point exactly opposite to its entrance. The incision is made slowly upward, close in front of and parallel to the plane of the iris, until the edge of the knife reaches the upper portion when it is directed slightly forward and the aqueous allowed to drain off, a bridge of uncut sclera is left and the knife slowly withdrawn, a solution of eserine introduced and a bandage applied. The relative positions of the incisions for iridectomy (/) and sclerotomy (S] are shown in Fig. 144. After either of these operations the wound sometimes closes imperfectly, and a cysioid cicatrix is formed. In these cases the wound generally closes after the operation, but after a time the ocular tension increases and the scar tissue being more distensible than other portions of the sclera, bulges out. Often the cicatricial tissue is so loose that the aqueous filters CHRONIC GLAUCOMA. 371 through it and collects beneath the conjunctiva in the shape of a large vesicle, which may cause much irritation or even inflammation, which may destroy the eye. The collection should be removed by pricking it with the point of a needle, and a compress bandage then applied to encourage healing. The curative value of either iridectomy or sclerotomy ia greatest in acute cases ; when the operation is performed imme- diately a complete cure generally results. In sub-acute cases with limitation of the field of vision, the improvement is very slow. In the chronic conditions slight improvement or the preservation of the remaining sight is deemed a good result. If the tension returns after an operation has been made it will be necessary to repeat it, and the iridectomy made opposite the first. If the vision is entirely destroyed by the prolonged pres- sure, no benefit will be derived from an operation, beyond the relief of the pain which may present. In very painful cases, when the condition is one of absolute glaucoma, enucleation may be demanded for the relief of the pain. If, as sometimes happens, the performance of an iridectomy upon one eye hastens the outbreak of the glaucomatous condition in the other, the second eye should be operated upon without delay. CHAPTER XX. DISEASES OF THE EETINA. ANATOMY. The retina is a delicate membrane which, contains the terminal filaments of the optic nerve. Externally it lies upon the choroid, while internally the hyaloid membrane separates it from the vitreous. It extends from the optic disc forward to the ciliary processes where it ends in an indented border, the ora serrata. From this portion there is continued forward on the ciliary processes a fine layer of transparent nucleated cells of columnar epithelium, which constitutes the ciliary portion of the retina, or the pars ciliaris retince, which dis- appears as the ciliary body passes into the iris. In the extent of the retina forward its thickness diminishes from ^V to ^O-Q of an inch. In the axis of the eyeball is what is termed the yellow spot, or macula lutea, somewhat elliptical in shape and about Y V ^ an i nc ^ i n diameter ; in the centre of this is a slight depression, the fovea centralis. To the inner side of the macula is the white or pinkish disc which marks the entrance of the optic nerve into the interior of the eye. Around the optic disc the retina is slightly elevated, and from the centre of the disc come the retinal vessels which branch above and below and radiate in all directions to supply the inner layers of the retina. Near the macula lutea vessels sweep off above and below (see Fig. 6, p. 11), and leave this region free of the larger vessels. The arrangement of the 372 AN ATOM Y OF THE RETINA. 873 capillary vessels in the macula, and their absence from the fovea, is well shown in Fig. 145. In the normal state the retina is transparent and of a pinkish color, but after death it soon becomes opaque. In the detailed examination of the retina (Fig. 146), ten layers are found, which, beginning with the inner surface of the retina, are described as follows: 1, membrana lim- itans interna, a thin struc- tureless membrane which separates the retina from the hyaloid; 2, a layer of optic nerve fibres; 3, a layer of ganglionic cells; 4, an in- ternal granular or molecular layer; 5, an internal layer of bodies, of na. us. granules or nucleus-like Ihree or four kinds; 6, an external granular layer; 7, external granules; 8, membrana limitans externa; 9, a layer of rods and cones; 10, pigment layer. In addition to these stratified layers certain fibrous structures are seen, which pass through the retina and con- nect the different layers and really form the tissue skeleton of the retina. These have been termed the supporting fibres of Mueller. Of the ten layers named, some are characterized as belonging to the nerve terminations, as the 2nd, optic nerve fibres ; 3rd, ganglionic cells ; 5th, inner granules ; 7th, outer granules ; 9th, the rods and cones. The remain- ing layers, except the pigment cells, are supposed to form the supporting structure of the retina and consist mainly of connective tissue. The layer of rods and cones, which con- stitutes the terminal elements of the optic nerve fibres, are DISEASES AND INJURIES OF THE EYE. of special interest. The rods have an elongated cylindrical form, while the cones are much shorter and thicker and are terminated by a thinner and more tapering process. The rods and cones are closely set together, but are not equally dis- tributed over the expanse of the retina; at the more peripheral portions of the retina, the rods far outnumber the cones, while at the macula lutea only cones are found. The pigment layer consists of flat, hexagonal, epithelial cells (Fig. 147), which are filled with brownish pigment, and on the surface towards the choroid are smooth, while from the inner surface prolongations of pigment extend between the processes of the rods and cones. It is this layer which is sup- posed to be the active agent in the secretion of the visual purple. At the macula lutea, the most sensitive portion of the retina, where direct vision occurs, the relation of the layers of the retina is somewhat different. All the layers except the 2nd (optic nerve fibres), which is absent, are thickened and only cones are found, while at the fovea all the layers are very much thinned, so that only the 7th layer, with the cones of the 9th, can be demonstrated, the cones here being crowded together and their bodies somewhat thinned. The blood supply and lymph spaces of the retina have been considered in the chapter on the general anatomy of the eye. The retinal blood-vessels are found only in the inner layers, the more external layers undoubtedly deriving their supply of nourishment from the choroid. The ophthalmoscopic appear- ances of the healthy retina (Plate Y, Fig. 1) are negative, inasmuch as, the retina being transparent, nothing of its tissue is seen except the blood-vessels, but we must be familiar with their normal appearance if we would be able to diagnose the pathological changes which may occur in the retina. The arteries are of a light red color, smaller in calibre and straighter than the veins, which are dark red, larger and more tortuous. The optic disc is easily distinguished by its white appearance from the surrounding retina, and occasionally fine, grayish lines may be seen radiating from the disc, which mark DISEASES OF THE RETINA. 375 the distribution of the nerve fibres. In rare cases these lines are very marked, and white, striated masses may be seen extending some distance out from one side of the disc or partially encircling it and giving to it an irregular outline. This is a congenital condition, and the appearance is due to a greater or less number of the nerve fibres passing through the lamina cribrosa and still retaining their medullary sheaths and appearing in the retina as opaque optic nerve fibres. The macula lutea is difficult to distinguish from other portions of the retina, except in children, unless the pupil is well dilated; it appears as a slightly defined grayish circular reflection with a central whitish dot indicating the position of the fovea. DISEASES OF THE RETINA. HYPERJEMIA or THE RETINA. Hyperaemia of the Retina is very difficult of recognition as the congestion of the vessels must be very marked to enable us to diagnose the condition. The vessels appear darker and more tortuous and the optic disc is more wavy in appearance and there may be slight clouding of the retina around the disc. Causes. It may be a transient condition depending upon over-use of the eyes, particularly in hyperopes and myopes, or result from the irritation of foreign bodies lodged in the cornea, or mental emotions, prolonged weeping, inflammatory affections of other portions of the eye, or accompany some derangement of the general circulation or of the digestive organs. Symptoms. The complaints are, usually, flashes of light, phosphenes, or other indications of irritation of the retinal elements. Treatment consists in the relief of all exciting causes, giving rest to the eyes, and using such remedies as Bell., Phos., Dubois., Conium, Bry., Puls., or Yerat. vir. AXJEMIA OR ISCHJEMIA OF THE RETINA results from obstruc- tion of the circulation in the retinal vessels, as will be considered under embolism and thrombus of the central artery. B76 DISEASES AND INJURIES OF THE EYE, It also occurs in cases of general anaemia, and has been observed in the prostration following cholera or other diseases. The failure in the retinal circulation occurs suddenly and there is immediate loss of vision, which is usually temporary, the sight returning after a few hours or days. Treatment. If the vision does not return after forty -eight hours under the administration of China, Ferrum, Phos., or other remedies that may be indicated, together with the use of nourishing food and stimulants, a paracentesis of the cornea should be made to relieve the intra-ocular tension and restore the circulation. EMBOLISM OR THROMBOSIS OF THE CENTRAL ARTERY of the retina, or one of its principal branches, gives rise to sudden loss of vision, which may be complete or partial, depending upon the position and size of the embolus. The vision may be slightly improved by the establishment of collateral circulation, but it is not usually permanent, and the retinal function is lost, or inflammatory changes occur, characterized by oedema of the retina, about the disc or yellow spot, which gives to the choroid a misty appearance, while in the fovea a red spot may appear which simulates a hemorrhage at this point. Later, the redness becomes paler and the retinal vessels affected, when detected, may appear as a whitish cord or not changed, except from the absence of producible pulsation. In a few weeks the disc appears white and passes into a state of atrophy. These cases, which occur very rarely, may arise in connection with diseases of the heart, and according to some authorities are, in the majority of cases, due to hemorrhages in the optic nerve sheath which present the same ophthalnioscopic appearances. Treatment is unavailing, as the sight is completely lost, yet such remedies as Crotalus, Lachesis or Prunus, which may cause absorption of the blood, may be tried when the diagnosis is doubtful. HEMORRHAGES INTO THE RETINA. Blood effusions into the retina occur spontaneously in persons of a hemorrhagic diathesis or those suffering from menstrual derangements ; also DISEASES OF THE RETINA RETINITIS. 377 from degeneration of the blood-vessels, cardiac disease, and from injuries and diseased conditions of the eye, as glaucoma, choroidal diseases in myopic eyes, or inflammation of the retina itself. Symptoms and Diagnosis, The vision is affected according to the location and extent of the effused blood and as it approaches or covers the macula lutea. Hemorrhages into the retina are readily recognized by means of the opthalnioscope as red patches, and their appearance depends upon the loca- tion and depth of the effusion. If they occur in the vicinity of the optic disc, they are generally more superficial and present a somewhat striated and irregular form as they spread through the nerve fibre layer and cover the retinal vessels. If the patches are deeper in the retinal tissue, they are smaller, the edges more rounded and the retinal vessels may be seen to pass uninterruptedly over them. Prognosis. The effusion gradually becomes absorbed, and if very small, may leave no trace; more often pigment spots or deposits of white fibrin result, indicating inflammatory changes at the point. If the hemorrhage is extensive, retinitis is very sure to occur and serious secondary changes follow. If the hemorrhage has occurred in the macula, the sight is rarely regained, and even with the partial restoration of the vision, the layer of cones has generally sustained such displace- ment as to cause distortion and irregularities in the appear- ance of objects. Hemorrhages into the vitreous are often an indication of the diseases mentioned among the productive causes, and may also be the forerunner of cerebral diseases which may involve the life of the patient. Treatment. The eye must be given absolute rest and pro- tected from the light, and such remedies administered as may hasten absorption, together with others adapted for the condi- tion which may be the exciting cause. Of the remedies which may hasten the absorption of the effusion, Bell., Lachesis and Crotalus are to be used. 378 DISEASES AND INJURIES OF THE EYE. RETINITIS. Acute retinitis, uncomplicated with inflammation of the choroid, optic nerve or other portions of the eye, is very rare. The inflammatory process takes, usually, a more passive char- acter and the morbid changes occur more slowly. Of the many morbid changes which may occur in the retina, but few of them, however, take origin in, or are confined to, the retina itself. Inflammation of the retina causes certain changes in its structure which lessen its transparency by infiltration of its tissue, resulting in hypertrophy of its connective tissue structure which may cause considerable increase in its thick- ness and render it opaque. The exudative material may be serous, plastic or purulent. These exudations may be absorbed or pass into a state of sclerosis or fatty degeneration, and the integrity of the retina will suffer according to the extent and length of time the exudation remains. CAUSES. Retinitis more commonly follows inflammation of the choroid, yet we meet with uncomplicated retinitis which is the result of syphilis or some other constitutional dyscrasia, and in patients who have diseases of the kidney, diabetes, menstrual disorders, leucocythemia, malaria, etc. When asso- ciated with optic neuritis, brain diseases and other causes excite it. SYMPTOMS. There are no external appearances of disease in the eye, nor is there any pain, and the impairment of the vision is the only symptom complained of. The ophthalmoscopic evidences (Plate V, Fig. 4) consist of loss of transparency and the presence of opaque portions of the retina. The opacities vary in size and shape in the differ- ent varieties of retinitis; and with the white patches are seen more or less hemorrhagic spots. The varieties of retinitis have been designated, according to their ophthalmoscopic appearances and constitutional causes, into retinitis apoplec- tica, retinitis albuminurica, retinitis syphilitica, retinitis pig- mentosa, retinitis proliferans and retinitis leuc?emica. RETINITIS APOPLECTICA, or hemorrhagic retinitis, is charac- PLATE V Normal Fundus Optic Neuritis 5 Retinitis 4 Retinitis Albuminurica 6 Atrophy or 1 Optic Nerve After-Optic Neuritis Progressive Optic Nerve Atrophy. RETINITIS: APOPLECTICAALBUMINURICA. 379 terizecl by the effusion of blood into the retina in spots of varying size, usually small, which are disseminated over a large portion of the retina and confined to one eye or affecting both. In addition to the effused blood, there is always evi- dence of inflammation of the retina and optic nerve. The optic disc is hyperaemic, the retinal vessels are enlarged and tortuous, and there is a serous effusion, or small patches of exudation here and there are observed in the retina. Causes. Atheromatous conditions of the blood-vessels, diseases of the heart, as hypertrophy and changes in the aortic valves, together with a syphilitic, rheumatic or gouty diathesis seem to furnish the causes of this form of retinal disease. The retinitis which occurs in diabetes frequently assumes the hemorrhagic form. Symptoms. The chief subjective symptom is more or less sudden loss of vision; the objective symptoms consist in the exhibition of spots of effused blood in the retina, which are found along the vessels, and the hazy condition of some portions of the retina from infiltration, or the appearance of exudation. Prognosis. The prognosis depends somewhat upon the cause, but more upon the extent and location of the hemor- rhage. If the hemorrhages are marked in the macula lutea or appear in the fovea, central vision is almost invariably destroyed, while if they affect the more peripheral portions of the retina and the macula is unaffected, and the hemorrhages are promptly absorbed, the^result may not be very serious to vision. As a rule, however, the blood is absorbed very slowly and months pass without the effusion clearing up. If the vision is seriously affected the prognosis is usually unfavor- able, as entire restoration is very rare, but if the macula has been implicated there is no probability of the return of central vision. It should be remembered that similar effu- sions are liable to occur in the brain from the same causes, and life be endangered. Treatment. Kest from all mental labor and cerebral excite- ment should be secured, and due consideration given to the "380 DISEASES AND INJURIES OF THE EYE. exciting causes. In severe cases, when the hemorrhages are increasing, the eye should be bandaged and the patient con- fined to bed. In milder cases the patient may have the eyes protected by dark glasses and be allowed moderate exercise. Bell., Phos., Lachesis, Crotalus and Merc, cor., hasten absorp- tion and improve the condition of the retina. RETINITIS ALBUMINUKICA, or nephritic retinitis, is a form of retinal inflammation which is characterized by an exudation of albuminous material into the tissue of the retina, which soon passes into fatty or fibrinous degeneration, affecting both the nerve fibres and the connective tissue of the retina. Both eyes are almost always diseased. Causes. Albuminuric retinitis is perhaps the most common form of inflammation which is confined to the retina, and is due to some lesion of the kidneys. It is frequently the first intimation of Bright's disease, and may precede all evidence of albumen in the urine for some weeks, or may appear only in the later stages of the disease. It occurs in about eight or nine per cent, of all cases of Bright's disease and usually in the chronic form, and here is more commonly associated with contracted kidney. The albuminuria of pregnancy or scarlet fever may also cause the disease. Any form of kidney disease, as waxy or fibrous degeneration or white hypertrophy, which produces an ursemic condition of the blood, is sufficient to excite the retinal inflammation. Symptoms and Diagnosis. The failure of the vision is the first symptom which may indicate the eye affection. The ophthalmoscopic picture is a very striking one (Plate V, Fig. 4). The optic disc is more or less hyperaamic and swollen, with indistinct edges, and the vessels turgid, or again the disc may appear flat, white, and the vessels but little changed. In the retina, however, at some distance from the disc, and frequently in the region of the macula, are observed the chief features of the ophthalmoscopic appearances; these consist of opaque white spots of varying size, often very large and striated, which are due to fatty degeneration of the connective tissue of the retina or sclerosis of the layer of the optic nerve RETINITIS ALBUMINURICA. 381 fibres. Hemorrhages are common and vary in size. The retinal vessels are covered by the white patches, or hemor- rhages, in a portion of their course and often the exudations are observed along the sides of the vessels. The white patches may consist of white dots which are grouped around the region of the macula, showing white lines which radiate from the fovea with dots between, and the retinal changes appear confined to the region of the yellow spot. In most, cases the patches are much larger and coalesce, forming a. more or less distinct zone around the disc, with another zone, between the disc and exudation, of apparently healthy retina. In rare cases we may find what would seem to be the primary stage of the disease, which consists of a delicate haziness of the retina as if from serous infiltration. As the cases do not usually present themselves until the disease is more advanced, there is no opportunity offered for a frequent examination of the eye in the early stages. Prognosis. Cases occurring during the course of acute disease of the kidney usually clear up and leave little impair- ment of the vision unless the macula has been affected, when there is a prompt recovery from the kidney lesion. The course of retinitis in the chronic diseases of the kidney, varies, with the condition of the latter. The prognosis is very grave as the vision is very greatly impaired, although total blindness does not usually occur, but as the eye affection keeps pace with that of the kidney, there is little to be expected from the treatment. Treatment. The treatment of retinitis is essentially that of the disease upon which it is dependent. Protection glasses, and complete rest for the eyes, with such bodily exercise as may be proper for the general condition, are necessary. Inter- nally, those remedies which are applicable to the cause of the disease will be indicated. Among the remedies particularly suitable to the condition of the eye in Bright' s disease, Merc. cor., and Gels, are the only ones which have seemed at all beneficial. In retinitis arising during the course of preg- nancy, Gelsemium and Apis have been useful. In a case of 382 DISEASES AND INJURIES OF THE EYE. retinitis associated with post-scarlatinal dropsy, a cure was effected by the use of Apis. EETINITIS SYPHILITICA differs from the two forms of retinitis just described, in that the retinal changes are due to infiltration with serum and fibrine, and of lymph corpuscles, with resulting hypertrophy of the connective tissue. Hemor- rhages and large patches of sclerosis or fatty degeneration are commonly absent, and there is a greater tendency to choroidal implication than with the other varieties. Causes. The disease appears usually among the later secondary symptoms of syphilis, and also among the tertiary symptoms of inherited syphilis. In women it may appear among the first symptoms of acquired syphilis, the primary sore and the light secondary symptoms having been unobserved. Symptoms and Diagnosis. The sight is often greatly impaired when but slight changes are observable in the retina, and, on the other hand, the vision may be but slightly disturbed when the retinal lesion is very great. The retina, particularly at the centre of the fundus, or along the vessels, appears hazy, and yellow spots of exudation are discernible ; these are often very minute and granular and more frequently appear about the macula lutea, where the disease shows a tendency to locate. Patients not infrequently complain of phosphenes, flashes of light, scotoma, and changes in the appearance and size of objects, from the disturbances of the relation of the cones at the yellow spot. One eye or both may be affected and the vitreous may become hazy. Prognosis. The disease may last from three to eight weeks or as many months and shows a great tendency to recurrence. Many cases recover without serious impairment of sight, if there is no implication of the choroid and the general condi- tion is fair. When the macula is the seat of the lesion, the prognosis becomes grave, as the vision is always impaired and in many cases destroyed. Atrophy of both the retina and optic nerve may follow the retinitis, or the latter may be the forerunner of brain disease. Treatment. The treatment is to be directed to the constitu- RETINITIS PIGMENTOSA SYMPTOMS. 383 tional causes, and of the remedies which are likely to be further indicated for the general condition by the eye lesions, Kali iod., Merc. cor. and Aurum may be mentioned. RETINITIS PIGMENTOSA is a chronic form of progressive inflammation which manifests itself by proliferation of the connective tissue of the retina and its pigment epithelium with consequent atrophy of the nerve elements. The condi- tion appears to be one of atrophy of the whole tissue of the retina with proliferation of the pigment. Its pathology is still in doubt, but it is probably more a degenerative condition which may be preceded by slight inflammatory symptoms. Causes. The causes are unknown, but the malady is usually hereditary, at least more than one member of a family are commonly affected. Symptoms. The disease is usually discovered in conse- quence of the patient's complaining that vision is defective except in very bright light, and that late in the day, or during twilight, or after dark, vision is very poor or impossible. This condition of the vision, hemeralopia, or night blindness, arises because the retina requires the full stimulus of daylight to enable it to act. In addition to this, the field of vision is contracted, and as the disease advances lessens, until at last central vision disappears and complete blindness follows. The ophthalmoscopic appearances in the early stages of the disease are very characteristic; toward the equator of the fundus numerous irregular mossy-like patches of pigment with star-shaped projections are seen, particularly along the line of the blood-vessels. The vessels are lessened in calibre and straighter; as the disease advances these pigmentary changes become more numerous and approach the disc, which becomes whiter, the blood-vessels are attenuated, the retina hazy, and, as the disease involves the macula, the vision disappears entirely. Prognosis is unfavorable, as, in the present state of our knowledge of therapeutics, the disease results in complete blindness. The time necessary for the completion of the atrophic process is often many years, as it advances slowly. 384 DISEASES AND INJURIES OF THE EYE. Treatment As yet nothing has been found which seems to have any effect upon the disease beyond those measures which are instituted to improve the general condition of the patient, and such care of the eyes as may retain the sight as long as possible. Temporary benefit sometimes results from the use of Lycop. and Phosph. EETINITIS PROLIFERANS is a rare form of retinal inflam- mation, which is characterized by the development of connective tissue in the vitreous. KETINITIS LEUC.EMICA is also a very rare variety of retinitis which occurs in some cases of leucocythsemia. The fundus of the eye presents a yellow aspect, with white patches of lymph corpuscles and hemorrhagic spots scattered over the retina. DETACHMENT OF THE KETIXA. Separation of the retina by effusion of blood or serum between it and the choroid, may take place in different portions of the fundus and may be partial or complete. If the effusion takes place in the upper portion, the fluid gravitates to the bottom, as in Fig. 1*48, detaching the retina as it works down, while the upper portion may again become FIG. 148. adherent. Hence the displacement of the retina is more frequently observed in the lower part of the fundus. Causes. The most frequent cause of retinal detachment is myopia, particularly of a high degree and when associated with choroidal diseases and fluidity of the vitreous. It occurs, however, in emmetropic eyes as the result of severe injuries to the eye, of iritis, choroiditis, and neuro-retinitis with vitreous changes, or in derangements of the nerves with lessened pres- sure in the vitreous, as indicated in diminished eyeball tension after injuries that have induced inflammation, with subsequent fluidity of the vitreous. The detachment may be complete, the retina having a funnel shape with the apex at the optic disc. Sympioms. Detachment of the retina causes a defect in the field of vision corresponding to the location of the separation;. DETACHMENT OF THE RETINA. 386 if the detachment occurs in the lower portion of the retina, the patient is unable to see anything above a certain line. The disturbance of vision varies with the amount and location of the detachment; if the retina is detached at or near the macula, the impairment is much greater, than if a more extensive sepa- ration exists at its periphery. The patient may first notice that the vision is clouded, and objects appear wavy or distorted, and fringed with prismatic colors. Again, colored or white bodies appear before the eye or flashes of light arise from the irritation of the retinal elements. "With the ophthalmoscope detachment is easily diagnosed, as the separated retina presents a bluish-gray, floating, tremulous, wave- like opacity which is thrown into folds, or has an undulating appearance on any motion of the eye, as in Fig. 149. If the FIG. 149. retinal vessels are traced from the disc to the detached portions, they will be seen to end abruptly or bend backward, or as they pass over the projecting retina they are nearer to our eye and require a change of focus from that necessary to observe the vessels on the other portions of the retina. When the detachment is complete the vision is com- pletely destroyed, and the retina appears as an opaque bluish mass behind the lens, if the lattor is not already cataractous. Prognosis. In rare cases absorption of the fluid with re-at- tachment of the membrane and restoration of the vision takes place. As a rule these cases of detachment present an unfa- vorable prognosis. Some cases may remain stationary, but more frequently the effusion increases until the separation becomes extensive or complete and the vision destroyed. Treatment. The operation of puncturing the retina by the introduction of a cataract needle through the sclerotic has, in the hands of some operators, proved beneficial, but the opera- tion has not been sufficiently successful to make the procedure of any value. The best method of treatment, if the detach- ment is recent, is to confine the patient to bed, bandage the eyes, and administer such remedies as may induce absorption- 25 386 DISEASES AND INJURIES OF THE EYE. If the detachment is old, the eyes should be protected from the irritation of light by dark glasses and all use of the eyes avoided. Occasionally the local use of atropine is advanta- geous, the rest for the ciliary body which results from its use preventing further detachment The most brilliant results have followed the administration of our homoeopathic remedies in some of these cases, particularly Gelsemium, Arnica and Aurum. Benefit has also been derived from Apis, Merc, and Digitalis. Other remedies will undoubtedly bo found valuable in the treatment of detachment as opportunities for the clin- ical application of our remedies to the condition increase. FUNCTIONAL DISEASES OF THE RETINA. HYPERJESTHESIA RETINA or extreme sensitiveness of the retina may be a symptom of inflammation of that tissue, but is also the result of close application of the eyes in fine work on bright or glistening objects, as in two cases which have come under my notice where the condition resulted from prolonged efforts with the microscope in the one case, and the other occurred in a metal turner who worked on brass disks in a bright light. In these cases there were no changes in the retina beyond a possible hypersemic condition. It is more frequently met with in hysterical or hypochondriacal people who generally present some refractive trouble, associated with accommodative or muscular asthenopia, and usually follows an. attack of illness. Two cases I have seen follow the puerperal condition. Symptoms. There is great sensitiveness to light, and often complete inability to use the eyes. Exposure to light, or attempted use, brings on lachrymation, pain and blepharospasm. Milder cases may complain only of dazzling, or the retinal impressions may persist for a longer time than usual and interfere with the rapid inspection of objects, or remain after the eyes are closed. These patients in severe cases confine themselves to close rooms from which every ray of light is excluded or even then keep the eyes bandaged. SNOW BLINDNESS NYCTALOPIA HEMERALOPIA. 387 Prognosis. The prognosis is favorable, as the proper treat- ment is prompt in relieving the condition, and the dread of blindness, which is the reactive cause, may be relieved by encouraging assurances, after a complete examination has been made. Treatment. An examination of the eyes should be made even if it is necessary to administer an anaesthetic, when any refractive errors must be determined by the ophthalmoscope, and in the absence of any retinal changes which may be pro- ductive of the condition, the patient should be assured of a full recovery. This encouragement itself is productive of the greatest good, as these cases commonly appear in nervo-hyster- ical subjects. Locally atropine may be useful, and the patients should be admonished not to exclude the light but gradually accustom the eyes to it, and this will aid materially in relieving the fears of the patient. Any error of refraction should be corrected as soon as possible, and the general condition of the patient improved by proper hygienic measures. The proper homoeopathic remedy is invaluable in the treatment of these cases and the results of its administration are wonderful at times. Of these remedies Bell., Conium, Ignatia, Macrotin, Nux Vomica and Natrum mur. are particularly serviceable, while Acnoite, China, Hyos., Lactic acid and Merc. sol. may be indicated more rarely. SNOW BLINDNESS is an affection resulting from prolonged exposure to the bright reflection of the light from areas of snow and during winters which are accompanied by great snow falls which remain for weeks or months. These cases are frequently met with in our northwestern states. There is often extreme irritability of the eyes with conjunctival hyper- semia, pain and extreme photophobia. The immediate symp- toms may pass off in a few hours or days, but in the cases which usually come to the city for treatment there is a marked hypersesthesia of the retina, which may persist for weeks or months afterwards. The treatment is the same as that already given for hyperaesthesia of the retina. 388 DISEASES AND INJURIES OF THE EYE. NYCTALOPIA or day blindness is sometimes applied to certain cases of hypersesthesia retinae where the patients are able to use the eyes in dimly-lighted rooms or at night, and yet are unable to do any work during day-time, or see when the eyes are exposed to bright sunlight. ANESTHESIA RETINAE, or torpor of the retina, is a condition opposite to that just described in which vision is only possible in bright light. From observation and experiments which I have made in the provings of certain remedies, it seems to me to be dependent upon the defective innervation which lessens the rapidity of the secretions of the visual purple, inasmuch as the condition is rapidly improved by the internal adminis- tration of low attenuations of Jaborandi and Agaricus and the higher attenuations of Lycopodium and Hepar s. Among the causes which may be mentioned is exposure to bright lights, especially in anaemic patients. It is also not uncom- mon in sailors who are exposed to the bright sun of the tropics in long voyages when the night is bright as well as the day. There are certain cases, as those occurring in squint from non-use of the eyes, or concussion of the eye, or in senile degeneration of the retina, as well as those depending upon atrophic conditions of the optic nerve and retina, which are not benefited by remedial treatment. HEMERALOPIA, or night blindness, is a term which is often applied to those cases occurring where the vision is better during the day-time than by dim or artificial light. In cases presenting these symptoms we should closely examine the retina for some indication of retinitis pigmentosa, of which it is a common symptom. COMMOTIO EETINE is a term applied to sudden loss of vision occurring from concussion of the eyeball, after blows received upon the eyeball, or upon neighboring parts and also after a stroke of lightning. There are usually no ophthal- moscopic changes apparent, yet the blindness is often complete and permanent. HEMIOPIA is loss of function of the lateral half of the retina, and usually affects the same side in both eyes. In this HEMIOPIA SCOTOMA. 389 condition there is loss of sight of the affected portion. Com- monly there is absence of the right or left half of the object, as when the right or left sides of each retina are affected, when the condition has been termed homonymous hemiopia; if both the internal or external sides of the retina are blind the hemiopia is termed respectively temporal or nasal. In very rare cases the upper or lower half of the field may be wanting. These cases are due to causes which lie in the brain or in the optic tracts behind the commissure. Some- times these affections are temporary, and due to some disturb- ances of the circulation. They are, however, commonly permanent, and associated with intra-cranial, syphilitic, tuber- cular or other diseased conditions of the brain, such as tumors. As a rule there is no change in the ophthalmoscopic appear- ances of the retina beyond a possible contraction of the arte- ries and hyperaemia of the disc. Treatment. The treatment must be directed to the discern- ible or probable cause. Certain of our remedies are useful in some of the cases and others, from their provings, give promise of value. When the upper half of the field of vision is defective, Aurum, Dig., and Gels, should be remembered, while for homonymous hemiopia, Calc. carb., Morph. sulph., Muriatic acid, Plumb., Sepia and Stramonium, and when the right half of the object is wanting Lith. carb. and Lycop. are to be considered. SCOTOMA is a term which is applied to other less extensive disturbances of the fundus of the retina; when only a small portion of the retina is insensible to light, this portion appears to the patient as a black spot in the field of vision, and is then termed a positive scotoma; when it is only found by an examination of the visual field and not apparent to the patient, it is termed a negative scotoma', of the latter the absence of that portion of the field which corresponds to the optic disc is apparent in the normal visual field; if the macula is affected a central scotoma is present. Scotoma commonly occurs in diseases of the optic nerve. Causes. Scotoma may appear as the result of injuries, 390 DISEASES AND INJURIES OF THE EYE. diseases of the retina or hemorrhages, opacities of the vitreous, or diseases of the optic nerve or of the brain. It may also occur from exposure of the eye to bright sunlight, as in observing an eclipse of the sun through a telescope, or from exposure to a very brilliant flash of lightning. In many cases, however, there is purely functional loss without apparent tissue change. Treatment. No special treatment of the eye is advisable in these cases beyond that indicated for the condition upon which the scotoma depends. COLOR BLINDNESS is an impairment of the function of the retina with inability to discriminate colors, and is usually- congenital; but it is also met with in an acquired form, in many diseases which affect the retina, optic nerve, brain or spinal cord. In the congenital form, which will be considered here, the patient's sight may in every respect be perfect, but he is unable to distinguish certain colors, as red, green or blue when there is partial color blindness, or there may be absolute color blindness, black and white alone being recog- nized. The most common form of color blindness is the partial, and occurs in about four per cent, of males to one per cent, of females, and is more frequent in the lower classes. Color blindness for red is the form most frequently presented. The faulty perception of the various shades of green are next in frequency, while the perception for blue or yellow is very rarely absent. The cause and pathology of color blindness is as yet unknown. The detection of color blindness is of the utmost importance and should be thoroughly understood, and of the numerous tests proposed, that of Holmgren, described in Chapter II, will afford the most satisfactory results. The condition is not amenable to treatment except in the acquired form, which will be considered in speaking of diseases of the optic nerve. ' TUMORS OF THE RETINA. GLIOMA of the retina, which has its origin in the granular layers or arises from the connective tissue of the retina, is the TUMORS OF THE RETINA DIAGNOSIS. 391 only kind of tumor occurring in this tissue. It consists of round cells and nuclei, imbedded in a small quantity of inter- cellular substance, and there is frequently a marked develop- ment of blood-vessels. As the growth increases and involves other portions of the eye, it partakes of the characteristics of sarcoma. It more commonly appears in one eye, but not infrequently affects both. Causes. Glioma arises almost exclusively in very young people, between the ages of one to twelve years, though it may appear as early as one month after birth, and would seem to be hereditary and dependent upon cancerous dyscrasia in the family. In extremely rare cases it may develop in older persons, when it first appears as a white patch in the retina. In general the causes are obscure. Symptoms and Diagnosis. The earliest symptom is a whitish, yellow, or bluish-white appearance of the pupil, which on examination is found to exist behind the lens, and the eye is devoid of vision. No pain or redness is present, and often the case is not brought for treatment until the eye becomes enlarged, or pain and congestion of the sclera occur. As the tumor grows it advances into the interior of the eyeball, producing atrophy and detachment of the retina as it proceeds. With the ophthalmoscope, it appears like detachment of the retina or inflammatory changes in the vitreous, which closely simulate it, and from which it must be distinguished by the absence of iritic adhesions, and from the history of the inflam- mation preceding the white or yellowish appearance of the pupil. The appearance of vessels upon the surface of the bulging mass, which do not correspond with those of the retina, will enable us to designate it from other affections. As the tumor increases in size the intra-ocular tension increases, and the pupil becomes dilated and the child complains of pain from the glaucomatous condition which occurs. Other portions of the tissues of the globe become involved with the increase of the tumor, and the lens loses its transparency, the cornea becomes opaque, and all semblance of the eyeball is lost in the protruding mass which extrudes between the lids, 392 DISEASES AND INJURIES OF THE EYE. and appears as a fleshy body, secreting a sanious discharge and subject to frequent hemorrhages in the advanced stage of the disease, when it is called fungus hcematodes of the eye. Prognosis. When the disease is recognized in the early stages, while confined to the retina, the removal of the eyeball with a portion of the optic nerve, which on examination shows no sign of implication, is usually favorable. The case, how- ever, is even then not safe until several months or a year have passed without indications of the return of the growth. In the majority of cases the removal of the eye is not acceded to, or the disease has progressed along the optic nerve so that the brain is oftentimes affected, or the contents of the orbit have become infiltrated with cancerous cells, so that death follows at an early date, from intra-cranial tumor or exhaustion due to the cancerous cachexia. Treatment. Immediate removal of the ball with as great a portion of the optic nerve as possible, is imperative when the tumor is confined to the interior of the eye. When it has extended beyond the confines of the globe the question of operative interference is a grave one, as often the complete extirpation of the contents of the orbit affords only temporary relief, the sarcomatous mass, under these circumstances, seeming to acquire fresh energy from the operative measures. In extremely rare cases the growth is reported to have been checked and the eyeball become atrophied, but this is so unusual, and the general tendency of the disease so fatal, that time should not be lost in awaiting probable absorption. After the removal of the growth, it is my practice to place these patients upon carbolic acid Ix in water, three times a day for several months, and good results have occurred from its use. CHAPTEE XXI. DISEASES OF THE OPTIC NEKVE. ANATOMY. The optic nerve connects the retina, its ultimate expansion for the reception of visual impressions, with the brain centres where perception takes place. It may be divided for examina- tion into three parts, the cranial, orbital and ocular portions. The ultimate origin of the optic nerve has been determined to be in the grey matter near the gyrus angularis of the occi- pital lobes. Other points of origin have been found in the optic thalami, corpora quadrigernina, posterior columns of the spinal cord, corpora geniculata, crus cerebri, tuber cinerum, the lamina cinera, and the anterior perforated space. The filaments connecting these portions of the brain and spinal cord are brought together to form the optic tracts, one on each side, which pass forward beneath the thalami and curve around the crus cerebri, to unite upon the olivary process of the sphenoid bone to form the optic chiasm or commissure. At the commissure a partial decussation of the fibres takes place, the outer fibres from the right optic tract passing direct to supply the right half of the retina of the right eye, the medial fibres passing to the more central portions of the retina while the inner portion goes to supply the inner half of the retina of the left eye. The fibres of the left tract are also 393 394 DISEASES AND INJURIES OF THE EYE. divided, the inner portion going to the inner half of the right eye, the medial fibres to central portions of the retina of the left eye and the outer portion passing direct to the outer portion of the retina of the left eye. At the commissure, fibres have also been described as connecting the two retinas and have been termed inter-retinal fibres; some intra-cranial fibres which pass directly from one side of the brain through the commissure to the other, without going to the eye, have also been found. The orbital portion of the optic nerve leaves the chiasm and enters the foramen opticum, becoming rounded and firmer and consists of several hun- dred bundles of nerve fibres which are sep- arated from each other by connective tissue. After passing through the foramen it emerges into the orbit where it curves slightly and passing forward enters the eyeball a little to the nasal side and slightly below its hori- zontal plane, and passes through the sieve-like membrane, the lamina cribrosa (Z Fig. 150) in the opening in the sclera, to be distributed to the various portions of the retina. The orbital portion of the nerve possesses two sheaths, an external one (e) the prolongation of the dura mater, and an internal one (i) formed by a continuation of the pia mater; the space (v) between these sheaths which also contains a prolongation of the arachnoid, forms the inter- vaginal or sub-dural space which communicates directly ANATOMY OF THE OPTIC NERVE. 395 with the cranial cavity. In this portion of the nerve, for a distance of 15 to 25 mm. behind the eyeball, a central canal (c) is formed for the transmission of the central artery and vein. The ocular portion of the nerve consists of that portion which enters the eyeball; the sheaths which have covered the orbital portion pass over and are continuous with the sclera, while the inter-vaginal space ends at this point, and the optic nerve fibres leave their medullary envelopes and pass through the lamina cribrosa, to emerge upon the interior of the eye, where they form a slight elevation circular in form and about 1.5 mm. in diameter, the optic disc or papilla. From the edge of the disc the nerve fibres curve gently to pass over into, the retina to form its nerve-fibre layer. The optic disc when examined by the ophthalmoscope presents a pinkish appearance which is generally deeper in color on the nasal side. The color is due to the blood in the capillaries, and as these blood-vessels diminish in number, as in atrophic conditions of the nerve, the disc becomes white. At the margin of the disc a black circle is distinguished, the clioroidal ring (P Fig. 150). This ring may be entirely- absent or appear as a crescent. Within this circle is discov- ered the scleral ring (T Fig. 150), white in color, and marking the limit of the pial sheath. In the centre of the disc where the central artery enters, a small funnel-like depres- sion the porus opiicus (c Fig. 150) is seen. When the nerve fibres begin to branch out into the retina at the lamina cribrosa and before reaching the surface of the papilla a more or less large hollow is observed in the disc; this constitutes, the physiological cup. When this excavation is large it may be difficult to distinguish it from the cupping which occurs in glaucoma ; it, however, never extends quite up to the scleral ring and does not present the displacement of the blood- vessels which are common to the pressure excavation. In these cases of cupping the translucent nerve fibres permit the lamina cribros-a to be seen and give to the optic disc a mottled appearance. B96 DISEASES AND INJURIES OF THE EYE. DISEASES OF THE OPTIC NEEVE. Any portion of the optic nerve, either in the cranium, in ihe orbit, or at its intra-ocular distribution may become diseased. The changes which occur may begin in the nerve itself, or extend from the other structures of the eyeball, from the orbital tissues, or from diseases of the brain, or more remote organs as those of the heart or kidney. The pathological changes which follow are similar to those which occur in diseases of the retina or other nerve tissues. We may have hypercemia, inflammation, or atrophy, of the optic nerve fibres. In the greater number of instances, the Tetina participates in the changes and the condition is one of neuro-retinal disease. Any lesion of the nerve may lead to changes in its struc- ture which prevent the transmission of visual impressions to the sensorium. HYPER.EMIA. Capillary congestion of the optic papilla is the common accompaniment of hypersemic conditions of other portions of the interior structures of the eye. It may be indicative of cerebral congestion, inflammation or other morbid processes of the base of the brain. It is also sympto- matic of certain anomalies of the refraction, as hyperopia and astigmatism, and of accommodative asthenopia and spasm of the ciliary muscle. Diagnosis. The optic papilla appears red, and new vessels are developed upon its surface and the edge of the disc, which before now were not noticeable. The margin of the disc becomes less distinct and ill-defined. The hypersemia may be so marked as to make the disc appear of the same color as the f undus. The vision is not affected. The light may or may not be disagreeable. Treatment. This must be directed to the cause of the hyperremia, as it is more frequently symptomatic than idio- pathic. Such remedies as Bell., Duboisia, Xux vom. and Phosph. should be considered. NEURITIS OPTICA SYMPTOMS. 397 NEURITIS OPTICA. CAUSES. Inflammation of the optic nerve is, in general,, symptomatic of some intra-cranial disease. It may arise idio- pathically in depressed conditions of the system, as in syph- ilis and in patients suffering from various toxic influences as tobacco, alcohol and lead, or accompany affections of the spinal cord. It may also be the result of local or general disturbance of the circulation, anomalies of menstruation, and uterine, heart or kidney diseases. It may occur during typhoid fever or an attack of facial erysipelas. Again, inju- ries, orbital cellulitis, periostitis, or tumors in the orbit may be the exciting causes. The majority of cases, however, are traceable to various intra-cranial diseases, such as meningitis^ inflammation, softening, or tumors of the brain. SYMPTOMS AND DIAGNOSIS. Optic neuritis (Plate V, Fig. 3) can be recognized by the ophthalmoscope only. It may exist without diminution of vision, or the failure of sight may be sudden and complete. As a rule there is generally a gradual loss of vision which can not be accounted for by manifest changes in the superficial portions of the eye, and an ophthal- moscopic examination reveals the condition of the optic nerve. The disc appears more or less swollen, its surface hyperaemic, the lamina cribrosa is obscured, and the outlines of the disc are ill-defined, irregular and the optic nerve fibres are some- what opaque from infiltration and give it the appearance known as "wooly di'sc." The veins are dilated and tortuous while the arteries appear smaller than normal, and the vessels are covered here and there by the swollen tissue. In rare cases spontaneous arterial pulsation is observed. Striated hemorrhages upon the disc or in the retina are sometimes seen. White patches of sclerosis or fatty degeneration are not infre- quently observed upon the disc or extending into the retina. Yery often the retina is clouded by infiltration for some distance beyond the papilla. If the inflammation extends some distance into the retina the condition becomes one of neuro-retinitis. 398 DISEASES AND INJURIES OF THE EYE. Cases of neuritis in which there is great swelling of the optic disc, with hypersemia and tortuosity of the retinal veins, but no extensive opacity of the retina constitute what is known as " choked disc." This variety of neuritis, which was first described by Yon Graefe, is dependent upon compression of the ocular portion of the nerve by fluid or inflammatory products which accumulate in the inter-vaginal space between the sheaths of the optic nerve. This space, enclosed by the tough dural sheath, is continuous through the optic foramen with the meningeal space in the cranium and is liable to disten- tion through any increase of fluid within the meninges. Hence this form of neuritis is commonly associated with intra- cranial disease. The unyielding scleral ring in addition to the lamina cribrosa, prevents a dilatation of the opening for the entrance of the optic nerve, so that any compression of the nerve behind its entrance from fluid collected in the sheath, fl ill proportionately retard the exit of venous blood. A slight oadema of the optic disc, results which tends to retard the venous flow still more and thus increases the cederna. The process may continue until inflammation, degenerative changes and atrophy occur. The trunk of the nerve is believed to be healthy in the majority of these cases. Our knowledge of the changes in the optic nerve which produce neuritis optica and their relation to the various intra-cranial diseases which so often cause or accompany the inflammation, is as yet incom- plete. Many of the cases which have been described as choked disc may be due to the extension of the inflammatory process along the nerve as in the so-called "descending neuritis." o o In neuritis descendens, a not uncommon form of inflammation which may or may not be associated with brain disease, the disc is congested and there is more or less infiltration of tissue of the papilla. The pathological changes of the papilla in choked disc consist of the separation of the optic nerve fibre bundles by the infiltrating serum, and the appearanca of varicose swel- lings upon the fibres. The veins become increased in number and calibre, and extravasations of blood may be found in and NEURITIS OPTICARETRO-BULBAR. 399 upon the papilla. There is rarely any hypertrophy of the connective tissue elements of the nerve unless the condition has existed for a long time, when the nerve fibres will be found atrophied. In the other forms of neuritis which are marked by much greater inflammation, and interstitial changes, there is extensive infiltration of cells, increase of connective tissue and blood-vessels, which is followed by degenerative changes in the optic nerve fibres, or atrophy ensues. Retro-bulbar neuritis is a variety of neuritis, also observed by Von Graefe, in which there is loss of vision associated with dilation of the pupil which is preceded by a slight congestion of the papilla and without inflammatory symptoms. Again there may be slight inflammation of the nerve observed which continues for a time and is followed by atrophy. Usually but one eye is affected. The loss of vision may be partial or com- plete and occur within a few hours or after a few days. ' There is generally no pain, except possibly a headache. There is usually central scotoma and loss of color perception. "With the ophthalmoscope the disc may appear normal, or present some injection, swelling and infiltration. The seat of lesion is located by exclusion in the orbital portion of the nerve and may follow upon typhoid or malarial fevers, measles, menstrual disorders, rheumatism, syphilis, etc. The changes which are observable in the various forms of neuritis are not always limited strictly to the disc as in a true papillitis, but in many cases there is more or less haziness and swelling of the retina which may extend some distance from the disc. In neuro-retinitis, hemorrhages, white or yellow dots or patches will be found in the disc and retina; these cases are generally presented in the advanced stage of Bright' s disease or may be due to cerebral disease and albumen not be present in the urine. PROGNOSIS. The prognosis as regards sight will depend upon the assumed cause, the length of time the inflammatory process has existed and the amount of tissue change which may be observed with the ophthalmoscope. The prognosis is generally unfavorable. The vision varies greatly during the 400 DISEASES AND INJURIES OF THE EYE. progress of the disease, and the ultimate effect upon the vision- will depend upon the changes which occur in the nerve tissues. Eesolution may take place and the vision be largely regained, or consecutive atrophy result with perhaps complete destruc- tion of vision. TREATMENT. The treatment will depend somewhat upon the supposed cause of the affection. Best of the eyes becomes necessary, all near work should be avoided and the eyes pro- tected from the light by smoked glasses. It is not necessary to confine the patient to a darkened room, except in extreme cases or when the cerebral disease is such as would require close confinement. Proper hygienic regulations should be observed in all cases. The remedies which will likely be indicated will depend upon the exciting cause and the con- comitant symptoms and are Bell., Duboisia, Phos., Puls., Xux vom., and Verat. vir. OPTIC NEEVE ATROPHY. In atrophy of the optic nerve, Ave distinguish two forms, a primary and a secondary atrophy. In the primary form the process begins in the nerve, while the secondaiy variety is preceded by an inflammatory process. The proper classification, how r ever, would be that of paren- chymatous and interstitial, as the pathological changes which occur can be definitely stated as due to sclerosis or fatty degen- eration or atrophy of the parenchyma of the nerve fibres, on one hand, or result from increase of the interstitial connective tissue, which exists between the nerve fibre bundles and conse- quent compression and atrophy of the nerve cylinders. CAUSES. While atrophy is the natural result of neuritis, it may also arise from various causes which lie in the brain or spinal cord, or follow injuries of the globe or orbit. Acohol- ism, syphilis, and inflammatory diseases of the retina or choroid not unfrequently cause it. Among other causes which may be mentioned are, the toxic effects of lead and tobacco, and certain diseases as facial erysipelas, measles, OPTIC NERVE ATROPHY. 401 menstrual derangements, fevers, diabetes and sclerosis of the spinal cord. In some cases no determinable cause can be found. SYMPTOMS AND DIAGNOSIS. The visual function is impaired, objects appear foggy and there is perhaps over-sensitiveness to the light which is followed later by a desire for strong light. The pupils are either contracted or normal and sluggish. The field of vision becomes contracted and the color perception, impaired or lost. The power to distinguish green is first lost, then that for red, and finally for blue and yellow when the perception for color has entirely disappeared. In certain cases of atrophy due to alcohol or nicotine poisoning the first color which is lost is red, or there may be only a central scotoma for red. The atrophy usually affects both eyes and is commonly associated with other nervous diseases, particularly of the spinal cord and due inquiry should be made into the mental and cerebral symptoms. The ophthalmoscopic appearances of both the primary and secondary forms are somewhat varied. The optic disc is opaque and white, or bluish white, and the capillaries of the disc absent. In some cases the lamina cribrosa may be seen and appears as a mixture of white and dark dots in the central portion of the disc. The papilla appears flat, or concave and excavated, and the outline of the disc sharply defined if the atrophy is well advanced. In the early stages of the secon- dary atrophy the disc may present an irregular outline and perhaps patches of pigment will be observed around it as in Plate V, Fig. 5. The vessels are diminished in number and calibre, and sometimes almost entirely absent. In some cases of progressive atrophy, the retina also partakes of the atrophic process and becomes thinned, so that the choroidal vessels become very prominent as in Plate V, Fig. 6. In the primary form of atrophy the color of the disc is usually white or grey while secondary atrophy presents often a yellowish appearance which later is replaced by a white or greyish color. TREATMENT. The treatment consists of the improvement of the general health by promoting the general nutrition. All 26 4:02 DISEASES AND INJURIES OF THE EYE. stimulants and tobacco should be avoided. The remedies which will be useful in atrophy are Strychnia, Nux vomica, Argent, nit., Phosph., and Zinc. phos. Occasionally, when other remedies fail, hyperdermic injections of the sulphate of strychnia, will be found beneficial. AMAUROSIS AND AMBLYOPIA. AMAUKOSIS is characterized by complete blindness with normal ophthalmoscopic appearances of the interior of the eye, as well as the absence of any external condition to account for the loss of vision. AMBLYOPIA is that condition, where there is partial loss of vision which is neither dependent upon any refractive error, nor upon any discoverable changes in the normal ophthal- moscopic appearances of the fundus. Causes. It is often congenital and often accompanies high degrees of hyperopia, myopia or astigmatism, and remains after the full correction of the ametropia. It is also present in strabismus, the squinting eye rapidly losing vision, the cause being supposed to be due to the fact that the eye does not participate in the visual act, and the condition has been termed amblyopia ex anopsia. Among other causes may be cited injuries to the globe, as blows upon the eye or orbit which cause concussion of the retina without any visible lesion of the eye. In these cases the pupil is rigidly contracted, and the vision is restored after a few days, or remains impaired. Injuries at the base of the skull not infrequently result in complete or partial loss of vision without perceptible changes in the eye. Concussions and injuries to the spine commonly produce loss of vision without ophthalmoscopic changes, and the amblyopia follows sometime after apparently complete recovery from the immediate effects of the injury, and is permanent. Extensive loss of blood in anaemic patients will sometimes occasion loss of vision which may be partial or complete and appear immediately upon the hemorrhage or not until some days afterward. Uraemia, from diseases of the AMAUROSIS AND AMBLYOPIA, 403 kidney, as in Bright's disease, and as found in diabetes frequently produces amblyopia which may be temporary or permanent and followed by atrophy of the nerve. It also arises from poisoning by various drugs, as lead, quinine, salicylic acid, aniline pigments, as well as silver and mercury. . Derangements of the nervous system, such as hysteria (ambly- opia hysterica} , paresis, and spasmodic affections are causative. Again it may arise without apparent derangement of the health. Sexual excesses and the use of tobacco (amblyopia nico- tina] and alcoholic stimulants (amblyopia poiatorum}, either singly or together produce amblyopia. In the amblyopia of tobacco and alcohol both eyes are affected and the condition may arise from either cause, and while the use of both are commonly combined in the same individual, yet undoubted cases occur in which the effect is produced by one or the other. Chronic alcoholism has long been recognized as productive of loss of vision and of optic nerve atrophy. The ophthalino- scopic appearances are usually a dull red disc with perhaps a hazy border and a torpid circulation of the fundus as evinced by the swollen veins. There is often an anaesthetic condition of the retina and later contraction of the visual field, and impairment of color perception. Tobacco poisoning exhibits still fewer ophthalmoscopic lesions, the nerve is more nearly normal, brighter in color, and later shows signs of inflammation or interstitial atrophy. The vision is often much reduced but there is rarely any con- traction of the field of vision. There is very frequently a central scotoma for red, which has been considered diagnostic. The central vision may remain good for light and form in these cases, but there is inability to distinguish red tints in this portion of the field. In either of these two forms of ambly- opia the loss of vision may come on insidiously and without headache or other symptoms. Inquiry in the majority of cases will however reveal the fact that the stomach has become deranged and that there is nausea and rejection of food particularly in the morning. 404 DISEASES AND INJURIES OF THE EYE. TREATMENT. The treatment of amblyopia is dependent entirely upon the cause, which is to be removed. When dependent upon injuries and general diseased conditions these demand immediate treatment and the amblyopia may disap- pear with the relief of the primary symptoms, or if persistent requires such medical treatment as may be indicated by the cause or concomitant symptoms. When excesses in venery, tobacco or alcohol, give rise to the condition, absolute absti- nence is demanded, and if the disc is normal and the field not limited, the abandonment of all indulgence, together with the use of such remedies as Strych., Nux vom., Arsenicum and Phosph. will result in complete recovery. SIMULATED BLINDNESS. Loss of vision is sometimes feigned for the purpose of escaping the performance of duty, to excite sympathy, or to recover damages for slight injuries. If the amaurosis is claimed to affect both eyes, it becomes a difficult matter to determine the malingering when the ophthal- moscopic appearances are normal. In the amaurosis of both eyes, which occurs from other causes than uraemia, the pupils are somewhat dilated and immovable, but the dilatation is not as great as that which follows the instillation of atropine. If the blindness is pretended it may be detected by any variation in the action of the iris under the influence of alternate light and darkness, or by bringing an instrument suddenly from above directly in front of the eye when a natural closure of the lids occurs to prevent impending injury to the eye when vision exists. When the imposition exists for only one eye, it is more easily determined. In this case if a prism of ten or fifteen degrees is placed before the healthy eye, with the base either up or down, and if the patient sees the dot on the line double as in the insufficiency of the recti muscles in asthenopia, the imposition becomes apparent at once. Other tests may be made with the stereoscope, the slides being so arranged that the picture before the healthy eye is darkened, while that before the supposed blind eye is clear, or a cross may be placed on the slide before one eye while a circle is fixed before TUMORS OF THE OPTIC NERVE. 405 the other; where there is binocular vision the patient sees a cross within the circle. In all cases great care must be exercised to prevent the patient from suspecting that the methods employed are to discover the dissembling, and he should be given to under- stand that the desire is only to determine the cause of the amaurosis. TUMOKS OF THE OPTIC NERVE are very rare and may be neuromata, carcinomata, or cystic, and may develop in the cranial or orbital portions of the nerve. There is usually a marked neuro-retinitis during the development of the tumor, or an exopthalmus when the growth involves the orbital portion when the tumors are within the orbit an operation is indicated and enucleation or extirpation of the contents of the orbit will become necessary. Glioma may arise in either the retina or optic nerve, and when developing within the globe frequently extends backward to the brain when unchecked by early removal INDEX. ABBREVIATIONS and signs for lenses, 98, 99 Abras praecatorius, 225 Abscess of cornea, 253 eyelid, 169 frontal sinus, 148 lachrymal sac, 168 globe, 355 Absorption of cataract, 316 Accommodation, 15, 27, 71 action of atropia upon, 46 action of calabar bean upon, 46 action of eserine upon, 46 anomalies of, 295 changes in, 16 diseases of, 295 paralysis, 295 paresis, 296 in presbyopia, 72 in spasm, 299 examination of, 27 muscle of, 7 negative, 72 power of, 73 range of, 27, 71 absolute, 72 monocular, 72 binocular, 119 negative, 28, 72 positive, 28. 72 relative, 28, 72 Accommodative asthenopia, 77, 297 movements, 16 Acne ciliaris, 174 Acnity of vision, 26 modes of estimating, 26 Acute retinitis, 378 Adams' operation for ectropium, 187 Adhesions of the pupil, 272 Advancement, operation of, 128 in muscular paralysis, 128 .Egilops, 170 Affections of the muscles of lids, 190, 191 After-images, 386 After-treatment of cataract opera- tions, 236 Albinos, 38 Albinism of the choroid, 357 Albuminuric retinitis, 380 Alcohol, a cause of optic nerve atrophy, 403 a cause of conjunctivitis, 202 Alcoholic amblyopia, 403 Allen, Dr. T. F., on use of Lachesis, 136 Alternating squint, 118 Alum, 166 Alumen exsiccatum pnlv., 163 Amaurosis, 402 simulation of, 404 Amblyopia, 118 exanopsia, 120, 402 anaemic, 402 from alcohol and tobacco, 403 from blood poisoning, 403 congestive, 403 from non-use, 402 from quinia, 403 potatorum, 403 in pregnant women, with albumi- nuria, 402 saturnina, 403 in strabismus, 118, 120 from tobacco, 403 nraemic, 402 Ametropia, 66 in strabismus, 119 Amyloid degeneration of conjunctiva, 223 Anaemia, 141 Anaemia of the retina, 375 Anaesthetics, 41 in cataract operations, 331 408 INDEX. Anaesthetics in strabismus operations, 123 Anaesthesia of the cornea, 364 of the retina, 383, 388 Anatomy and physiology, general, 1 Anchyloblepharon, 195 Anchylops, 170 Anel's canalicnlus probe, 154 Aneurism of ophthalmic artery, 147 of orbit, 147 Angiomata, 142 Angle alpha, 66 of vision, 66 of the iris, 12 Anisometropia, 99 Anomalies of refraction, 64 Anterior chamber, 4, 5, 6, 12 ciliary arteries, 10 ciliary veins, 12 elastic lamina, 235 polar cataract, 338 pole, 3 vascular zone, 23 Antero-posterior diameter of the eye- ball, 2 Anthrax of the eyelids, 171 Antrum of Highmore, 130, 149 injury of, 51 tumors of, 149 Aphakia, 339 Apoplexy of the retina, 376, 378 of the choroid, 357 Aqua chlori, 145 Aqueous humor, 4 evacuation of, 245 in iritis, 245 keratitis, 245 Aquo-capsnlitis [Vide Decemetitis] Arachnoidal space, 9, 132 cavity, 13 Arcus senilis, 258 Arlt, blepharoplastic operation, 189 operation for pterygium, 232 Aspirator, use of in periostitis, 138 Arteria centralis retinae, 11 hyaloidea, 341 Arteries of eye, 10 central, 8 anterior ciliary, 10 long ciliary, 10 short ciliary, 10 posterior ciliary, 10 Arterial loops of cornea, 11 Artificial eye, 308 pupil, 286 Associated action of ocular muscles, 104 Asthenopia, 77 accommodative, 77 due to hypermetropia, 77 muscular, 77, 113 Asthenopia, retinal, 386 Asthenopic headaches, 95, 114 Astigmatism, 16, 67, 92 acquired, 93 causes, 93 compound, 94 congenital, 93 diagnosis of, 95 hyperopic, 94 irregular, 93 mixed, 94 myopic, 94 regular, 93 simple, 94 ophthalmoscopic diagnosis of, 95 symptoms, 94 treatment of, 97 test cards for, 96 Ataxy, locomotor, a cause of amauro- sis, 401 Atresia of the lachrymal puncta, 154 Atrophy of the bulb, 210 of the optic nerve, 24, 400 Atropia, sulphate of, 45, 98 action of, on accommodation, 46, 296 on the iris, 46, 284 anomalous effects of, 46 in glaucoma, 363 in iritis, 274 in myopia, 90 poisonous symptoms, 46 strength of solution, 46 Atropiae sulphatis, 45 Atropine conjunctivitis, 206 Autumnal conjunctivitis, 205 Axis, optic, 3 length of, 65 visual, 3 length of, 66 BACILLI of retina, 373 Bandage, forms of, 42, 43 compress, 24 Bandaging, 42 Basedow's disease, 20, 137, 140 Beer's knife, 49 Bicarbonate of soda, 52 Binocular vision, 17 mode of examination of, 404 in strabismus, 122 Blackboard for recording visual field, 25 Black eye, 52 Blennorrhoea of lachrymal sac, 164 Blepharitis acuta, 169 marginalis, 174 Blepharo-adenitis, 174 Blepharoplasty, 189 Blepharospasm, 192 Blind spot of Mariotte, 17 INDEX. 409 Blindness simulated, 404 Blood-vessels of globe, 10 of macula lutea, 373 of retina, 374 Blood effused into anterior chamber, 58 into choroid, 63 into conjunctiva, 198 into eyelids, 52 into orbit, 51 into retina, 376 into vitreous humor, 61, 345 supply of eyeball, 10 Blue glasses, 70 ointment, 176 Boll, discovery of retinal purple, 17 Bonnet, capsule of, 101 Bony tumor of orbit, 144 Borax, 165 Boracic acid, 45, 155 Bowman's membrane, 235 canaliculus knife, 157 probes, 159 use of, 157 Brachymetropia (vide Myopia), 345 Brain tumor, a cause of neuritis, 397 Bright's disease, a cause of retinitis, 380 Brunettes, retina of, 38 Bulbus oculi (vide Eyeball) Bophthalmos, 266 Burnett, 205 Burns, 52, 53 from ammonia, 53 from acids, 53 of conjunctiva, 53 of lids, 52 from lime, 53 from mortar, 53 from molten metals, 53 CALABAR bean (vide Eserine) Calcareous deposits on cornea, 258 in meibomian glands, 231 Calculus, lachrymal, 155 meibomian, 231 Calendula, 45, 52 Calomel, 228 Canal of Petit, 312 of Schlemm, 5, 7, 12 Canaliculus, lachrymal, 2 division of, 154 obstructions in, 153 probe, 154 Canalus opticus, 13 Cancer of choroid, 356 of conjunctiva, 234 of cornea, 261 epithelial, 194, 234, 261 glio-sarcoma, 144 of eyelids, 194 Cancer of iris, 282 medullary, 144 of the retina, 390 of orbit, 144 Canthi, 167 Canthoplasty, 185, 186 Canthotomy, 185, 217 Canthus, external, 167 internal, 167 Capsule of Bonnet, 101 of Tenon, 2, 13, 101, 132 inflammation of, 139 of lens, 312 Capsular cataract, 338 anterior. 338 posterior, 338 Capsulitis, 132, 139 Carbolic acid, 155, 510, 225 Carbuncle of the eyelids, 171 Caries of the orbit, 139 Carter's test-cards, 96 Cartilage, tarsal, 168 Cartilaginous tumors of the orbit, 144 Caruncle, 195 inflammation of, 231 Caruncula lachrymalis, 196 Cataract, 313 anterior capsular, 338 atropia in, 314 black, 325 capsular, 245 causes, 60, 313 chalky, 324 complications, 326 congenital, 315 cortical, 321 diabetic, 313 diagnosis of, 314 duration of, 325 etiology of, 313 glaucomatous, 366 hard, 322 hypermature, 324 immature, 324 lamellar, 319 mature, 324 I mixed, 321 Morgagnian, 324 nuclear, 322 polar, 338 posterior capsnlar, 338 pyramidal, 245, 338 secondary, 339 soft, 315 symptoms of, 314 traumatic, 316 varieties of, 313 zonular, 319 Cataract, treatment of, 316, 320, 327 by couching, 330 by discission, 316 410 INDEX. Cataract, treatment of, by flap extrac- tion, 330 by Von Graefe's extraction, 331 by linear extraction, 318 by removal of lens in its capsule, 338 by reclination, 330 by scoop extraction, 338 by suction, 319 Catarrhal ophthalmia, 201 Cats'-eye, amaurotic, (glioma retinae) 390 Caustics, 161, 247 use of, 161, 224 Caustic, mitigated, 224 Cautery, galvanic, 161 Cavernous sinus, 11, 132 thrombus of, 147 Cavity, arachnoidal,13 Cells, endothelial, of iris, 8 ganglionic, of retina, 8 laminated, of retina, 8 Cellulitis, orbital, 133 Central artery of retina, 9, 11 Centre, optical, 66 of rotation, 2 Cerebral oedema a cause of neuritis, 398 Chalazion, 173 Chamber, anterior, 4, 12 effusion of blood into, 58 posterior, 4, 12 Chemosis of conjunctiva, 198 Chloral, 204 Chlorine water, 45 Chloroform, 41 in cataract operations, 331 in diphtheritic conjunctivitis, 219 Choked disc, 144, 398 pathology of, 398 Cholesterine crystals in lens, 324 in vitreous, 344 Chorea, 95, 114 Choroid, 4, 6 anaemia of, 351 anatomy of, 6, 347 atrophy of, 350 bony deposit in, 303 cancer of, 356 colloid disease of, 356 coloboma of, 357 detachment of, 57, 357 Choroid, diseases of, 348 hemorrhage from, 61 injuries of, 63 hyperaemia of. 350 layers of, 6, 347 pathological changes of, in M, 87 rupture of, 356 sarcoma of, 356 tubercles of, 356 Choroid, tumors of, 356 Choroidal ring. 37, 395 Choroiditis, 348 areolaris, 354 causes, 349 diagnosis, 350 disseminata, 353 metastatica, 355 plastica, 352 serosa, 357 symptoms of, 349 suppurative, 355 syphilitic, 353 Cilia, 168 Ciliary arteries, 10 anterior, 10 long, 10 short, 10 Ciliary body, 4, 7, 16 anatomy of, 291 hyperaemia of. 78 diseases of, 292 congestion of, 13 ganglion, 9, 10 muscle, 7, 9 affections of, 295 anatomy of, atony of, 297 paralysis of, 295 spasm of, 299 Ciliary neuralgia. 272 processes, 4, 6 region, injuries of, 295 spasm, 114 veins, anterior, 12 zone, 272 Circles of diffusion, 84 Circular venous sinus, 5 Circulation of nutrient fluid, 11, 12 of lymph, 11, 12 Circulus arteriosus major iridis, 270 minor iridis, 270 Coccius, 29 Cleansing the eye, 45 Clamp forceps. 174 Cold applications, 44 Coloboma of choroid, 357 of iris, 282 of lids, 194 Collodion, 183 Colloid disease of choroid, 356 Collyria, 203, 213, 224 Color, test for, 24 Color blindness, 24, 390 test for (Holmgren's), 24 Color of eye, 268 perception, 390 scotomata in optic nerve atrophy, 401, 403 in tobacco amblyopia, 403 Coloring matter of retina, 8 INDEX. 411 Compression, digital, in orbital aneu- rism, 147 Concomitant squint, 118 strabismus, 118 Condition of the lids, to examine, 20 Conducting filaments, 8 Cones* layer of, 8, 373 Confusion test, 24 Conical cornea, 259 treatment of, 259 Bowman's operation, 161 by iridectomy, 260 Von Graef e's operation, '260 Conjugate foci, 65 law of, 19 Conjunctiva, 2, 52, 53 amyloid degeneration of, 223 anatomy of, 196 bulbi, 166 burns of, 53 cul-de-sac of, 196 cysts of, 234 dermoid growths of, 234 diseases of, 196, 197 dislocation of lens beneath, 59 emphysema of, 198 epithelial cancer of, 234 examination of, 21 hemorrhage into, 198 foreign bodies upon, 53 hyperaemia of, 199 injuries of, 52 inflammation of, 200 lupus of, 234 pigment deposits of, 234 oedema of, 198 pinguecula of, 233 polypus of, 233 sarcoma of, 23r syphilitic ulcer of, 234 tumo -a of, 233 warts of, 234 wounds of, 53 Conjunctival discharge, contagious- ness of, 206, 216, 221 Conjunctivitis, 200 from atropine, 206 autumnal, 205 blennorrhoaic, 207 catarrhal, 200, 201 chronic, 202 croupous, 200, 217 diphtheritic, 200, 218 follicular, 226 gonorrhoeal, 200, 208, 214 granular, 209 membranous, 217 palpebral, 199 phlyctenular, 200, 227 purulent, 200, 206, 209 pustular, 227 Conjunctivitis, simple, 200, 201 spring, 205 trachomatous, 200, 219 vernal, 205 Contagious diseases of eye, 200 Contusions of eyelids, 52 Convergent strabismus, 118 Copper sulphate, 224 Corelysis, 290 Cornea, 4, 235 abrasions of, 55 abscess of, 253 anaesthesia of, 256 anatomy of, 5, 235 diseases of, 238 examination of, 22 fistula of, 245, 247 focal length of, 65 foreign bodies in, 54 globosa, 259 hernia of, 244 herpes of, 238 inflammation of, 239 injuries of, 54 neuro-paralytic affection of, 256 nerves of, 5, 237 opacities of, 257 paracentesis of, 245 perforation of, 244 sloughing of, 134 staphyloma of, 259 suppuration of, 253 after cataract extraction, 33? trephining of, 261 Cornea, tumors of, 261 ulcers of, 213, 242 asthenic, 242 causes, 242 chipping, 243 crescentic, 244 perforating, 243 ethenic, 242 superficial, 243 symptoms, 243 transparent, 243 treatment of, 245 vascular, 244 wounds of, 56 Corneal corpuscles, 236 ulcers, 242 fistula, 245 Corpora g^niculata, 8, 393 quadrigemina, 8, 393 Cosmoline, 209 Couching 330 Cream, use of, in burns, 53 Crystalline lens [see Lens] Cul-de-sac of conjunctiva, 196 Cyclitis, 293 sympathetic, 61, 304 traumatic, 295 412 INDEX. Cylindrical glasses, 99 lenses, 99 use of, in astigmatism, 99 Cyst of eyelids, 173 of conjunctiva, 234 in iris, 282 of orbit, 142 tarsal, 173 meibomian, 173 Cystic tumors, 142, 173, 234, 282 Cysticercus, of the orbit, 142 in vitreous humor, 346 Cystoid cicatrix in glaucoma, 370 DACRYO- adenitis, 152 Dacryo-cysto-blennorrhcea, 163 Dacryo-cystitis, 162 Dacryoliths, 155 Dacryops, 153 Daltonism (vide Color blindness) Decoction of chamomile, 45 calendula, 45 hops, 45 Decussation of optic nerve fibres, 9, 393 Defects of normal eye, 16 Delivery of lens, 335 Dermoid tumors of conjunctiva, 234 Descemititis, 256 Descemet's membrane, 12, 235 Desmarre's elevator, 47 clamp forceps, 174 paracentesis knife, 245 Destruction of lachrymal sac, 161 Detachment of the retina, 57, 384 choroid, 57, 357 iris, 58 Detailed examination, 70 Deviation, primary, of visual lines, 104 secondary, of visual lines, 104 in hypermetropia, 104 in myopia, 104 in paralytic affections of the ocu- lar muscles, 105 Deviation in strabismus concomitans, 120 Deviation, primary, 104 secondary, 104 Diagnosis of ametropia with the ophthalmoscope, 78, 89, 95 Diagrammatic eye, 14 Diameters of eyeball, 2, 3 Diffenbach's operation for ectro- pium, 187 Digital pressure in orbital aneurism, 147 Dilatation of pupil, 46, 283 Dilator muscle, 7, 269 Dioptric apparatus of the eye, 14 system, 68 unit of, 68 Dioptrics, table of, 67 Diphtheria, 218 Diptheritic conjunctivitis, 218 Diplopia, 17, 104, 105, 108 binocular, 105 crossed, 105, 106 direct, 105 hieronymous, 105 homonymous, 105, monocular, 105 operation for, 113 treatment of, 112 Direct examination with the ophthal- moscope, 34 Disc, optic, 9, 37 choked, 144 Discission, 60 Diseases of the muscles of the eye, 107 eyelids, 168 ciliary body, 292 choroid, 348 conjunctiva, 146 cornea, 238 iris, 270 lachrymal apparatus, 150 gland, 152 lens, 313 lids, 168 optic nerve, 399 orbit, 132 retina, 375 solera, 263 vitreous, 342 Disinfecting lotions, 45 Dislocation of the eye, 92 lens, 60, 339 Distichiasis, 180 Divergent strabismus, 126 Division of cataract, 316 ciliary muscle, 370 supra-orbital nerve, 192 Donders, Prof., 73, 76 on glaucoma, 363 on hyperopia, 80 on myopia, 76 on near point, 73 Double vision, 17, 104, 105 Douche, 45 Drainage of the eye, 12, 363 Dropsy of the eye, 266 Duboisia, 90 46, 117, 200 sulphate of, 46 solution of, 46 poisonous symptoms of, 47 Duct, lachrymal, 151 obstruction of, 154 nasal, 151 strictures of, 154 Dural sheath, 394 Dura mater, 9, 394 INDEX. 413 ECCENTRIC vision, 25 Ecchymosis of conjunctiva, 188 of eyelids, 52 Echinococcus in orbit, 142 Ectopia, 283 lentis, 339 Ectropium, 186 causes, 186 operations for, Adams', 187 Diffenbach's, 187 Graefe's, 188 Wharton Jones', 187 treatment by blepharoplasty, 189 tarsoraphia, 188 Eczema of the lids, 193 Effusion of blood into anterior cham- ber, 58 into choroid, 63 conjunctiva, 198 eyelids, 52 retina, 376 vitreous humor, 67 Egyptian ophthalmia, 220 Electricity in paralysis of ocular mus- cles, 111 Electrolysis, 148 in lachrymal stricture, 160 Elements, percipient, of retina, 8 Elevator, lid, Desmarre's, 47 Embolism of retinal artery, 376 Emmetropia, C6 Emphysema of eyelids, of conjunctiva, 198 Encanthus, 234 Enchondroma of orbit, 144 Encysted tumor of lids, 173 of orbit, 144 Engorged papilla (choked disc), 398 Entoptic phenomena, 16 Entozoa (vide Cysticercus and Echino- coccus,) Entropium, 183 acute or spasmodic, 183 chronic, 183 senile, 183 treatment of, 184 Hotz' operation for, 185 Enucleation of eyeball, 62, 307 Epicanthus, 194, 234 Epilation, 180 Epiphora, 153 Episcleritis, 265 Epithelioma, 194 of conjunctiva, 233 of cornea, 261 of lids, 194 Equator of globe. 4, 7 Erectile tumors of eyelids, 194 of orbit, 145 Errors of refraction, 54 Erysipelas, 133 Erysipelas of eyelids, 172 facial, 140 Erythema of eyelids, 133 Eserine, 41, 245 sulphate of, 47 use of, 47 solution of, 47 Ether, 41 Ethmoid cells, distention of, 148 Evacuation of aqueous humor, 245 of the eyeball, 259 Eversion of lids. 186 Evisceratio-bulbi, 259 Examination of eye, 20 by lateral illumination, 28 by focal illumination, 28 ophthalmoscopic, 29 Excavation of optic nerve, 395 atrophic, 401 glaucomatous, 364 physiological, 37, 395 Excision of eyeball, 307 of staphyloma, 259 Excoriation of lids, 175 Exit for aqueous fluid, 6 for lymph, 12 Exophthalmic goitre, 140 symptoms and diagnosis, 140 treatment, 141 Exophthalmus, 132, 137 Exostosis of orbit, 144 External rectus muscle, 9 paralysis of, 110 Extraction of hard cataract, 329 of foreign bodies from the eye, 62 Extirpation of eyeball, 307 of lachrymal grand, 153 of lachrymal sac, 161 Extraction of lens, 318, 339 by flap operation, 330 by Von Graefe's operation, 330 by linear incision, 318 Liebreich's method, 337 LeBrun's method, 337 by scoop operation, 338 by suction, 319 in its capsule, 338 Eye, ametropic, 66 anatomy of, 1 artificial, 308 diagrammatic, of Listing, 14 douche, 45 emmetropic, 66 enucleation of, 307 examination of, 19 general inflammation of, 355 injuries of, 50 lashes, 168 myopic, 67, 90 Eye-glasses, 68 shades, 44 414 INDEX. Eyeball, atrophy of, 134 blood supply, 10 displacement of, 137, 142, 143 lymphatic system of, 11 prominence of, 20 protrusion of, 132 causes, 132 Eyelashes, inversion of, 180, 183 transplantation of, 182 removal of, 180, 181 to destroy bulbs, 182 Eyelids, abcess of, 169 affections of, 168 anatomy of, 167 anthrax of, 171 baldness of, 176 blepharo-adenitis, 174 blepharospasm, 192 burns, 52 contusion of, 52 carbuncle of, 171 chalazion, 173 diseases of, 167, 168 distichiasis, 180 ecchymosis of, 52 ectropium, 186 eczema of, 193 emphysema of, 169 encysted tumors of, 173 entropium, 183 epicanthns, 194 epithelial cancer of, 194 erysipelas of, 172 erythema of, 172 to evert, 21 eversion of, 186 herpes, 193 hordeolum, 172 hyperaemia of, 172 inflammation of edges of, 174 injuries of, 51 inversion of, 183 malignant pustule of, 171 nsBvus of, 194 oedema of, 169 to open, 20 paralysis of upper, 110 ptosis of, 190 spasm of orbicularis of, 192 tinea tarsi, 174 trichiasis, 180 tumor of, 195 ulcers of, syphilitic, 193 warts on, 194 wounds of, 52 Examination of eye, methods of, 19 detailed, 20 general, 19 Exophthalmus, 132 FARAD AISM in paralysis, 111,191, 102 Faradaism in asthenopia, 115 Far point, 71 Far sight (vide Hypermetropia) Farsightedness (vide Hypermetropia) Fascia, oculo-orbital, 132, 168 tarso-orbital, 132, 168 Fatty degeneration of retina in retin- itis albuminurica, 380 Fibres of optic nerve, 394 Fibroma of orbit, 142 Fibromata, 142 Field of vision, 17, 24, 25 for colors, 26 contraction of, 365, 383, 401 in detached retina, 384 in injuries of vitreous, 61 in glaucoma, 365 in retinitis pigmentosa, 383 false projection of, in diplopia, 108 equilateral or homonymous con- traction of, 389 examination of, 25 Fissura palpebrarum, 167 Fissure, inferior orbital, 131 spenoidal, 131 spheno-maxillary, 131 superior maxillary, 131 palpebral, 167 Fistula corneae, 245 of cornea, 245 lachrymalis, 162 of lachrymal sac, 162 Fixation, central, 24 eccentric, 25 forceps, 49 Flap extraction of cataract, 330 Flashes of light in eye (vide Phos- phenes) Flax-seed poultices, 45 Fluid cataract, 324 vitreous, 344 Focal distance of lens system, 65 illumination, 28 length of cornea, 65 of lens, 65 Focus, principal posterior, 15 principal, of cornea and lens, 65 of lenses, 65 Foci, conjugate, 65 Fold, retro-tarsal, 196 Fomentations, hot, 44 Forceps, fixation, 49 Foreign bodies on the conjunctiva, 52, in ciliary body, 62 on cornea, 54 to detect, 28 in eye, 62 hook for, 62 on iris, 58 in lachrymal apparatus, 52 in lens, 60 INDEX. 415 Foreign bodies within the eyeball, magnet for, 62 in orbit, 51 in vitreous, 61 Fornix of conjunctiva, 196 Fossa, hyaloid, 341 patellaris, 341 Fourth nerve, 9 Fovea centralis, 8, 15, 372 to examine, 38, 375 Fractures of walls of orbit, 50 Frog-spawn granulations, 220 Frontal sinus, abscess of, 148 distention of, 148 Fundus oculi, 37 of brunettes, 38 ophthalmoscopic appearances of healthy, 37 of Negroes, 38 of Albinos, 38 cause of color of, 38 Fungus hsematodes, 392 GALVANISM in muscular paralysis, 111, 191 in muscular asthenopia, 115 in exophthalmic goitre, 141 Galvano-caustic, 161 Galvanic cautery, 161 Ganglion, Meckel's, 131 Ganglionic cells, 8 Gasserian ganglion, 193 General examination of the eye, 19 considerations of treatment, 41 survey of the eye, 20 Gerontoxon (arcns senilis) 258 Gland, lachrymal, 151 diseases of, 152 extirpation of, 153 meibomian, 168 Glass, crown, 68 pebble, 68 Glasses, for aphakial eyes, 369 colored, 70 concave, 69 cylindrical, 70 decentred, 115 of double focus, 92 protective, 70 spherical, 69 stenopaic, 70 pantoscopic, 92 Glaucoma, 24, 359 absolute, 365 acute inflammatory, 360 causes, 360 diagnosis, 360 symptoms, 360 treatment, 361 chronic non-inflammatory, 361 causes, 362 Glaucoma, diagnosis, 364 consecutive, 360 eserine in, 361 excavation of nerve in, 364 fulminans, 361 hemorrhagic form of, 3, 170 iridectomy in, 369 maligna, 370 medical treatment of, 36i) myotomy in, 370 nature of, 363 neuralgic pain in, 364 operations for, 370 ophthalmoscopic diagnosis of, 365 premonitory symptoms, 362 prognosis in, 371 sclerotomy in, 370 secondary, 360 simplex, 361 snbacute, 361 symptoms, 362 treatment, 368 varieties, 359 Glioma of retina, 390 Glio-sarcoma of retina, 390 Globe, dislocation of, 132 foreign bodies within, 62 suppurative inflammation of, 60 tension of, to determine, 23 inflammation of the whole, 132 Glycerine, 156 Goitre, exophthalmic, 140 Gonorrhoeal ophthalmia, 214 iritis, 271 Gouge, 55 Gouty diathesis in iritis, 271 Graefe, von, Prof., 205 compress bandages for the eye, 42 operation for linear extraction, 330 operation for ectropium, 188 Granules of retina, 8, 373 Granular conjunctivitis 219 lids, 219 ophthalmia, 219 Granulations, acute, 221 chronic, 221 vesicular, 226 hard, 220 soft, 226 Graves' disease, 140 Green's test cards, 90 Groove, lachrymal, 130 Gruening's magnet, 62 Gunshot wounds, 51 Gunpowder, 52, 53 HALOS, 367 Hard cataract, 332 Hardness of globe (vide Tension) Hay fever, 205 416 INDEX. Headache, asthenopic, 95, 114 Helmholtz, 29 ophthalmoscope of, 30 Hemeralopia, 388 in retinitis pigmentosa, 383 Hemiopia, 24, 388 equilateral, 389 homonymous, 389 temporal, 389 Hemorrhage into anterior chamber, 58 from choroid, 63 into conjunctiva, 198 into orbit, 51 into optic nerve sheath, 376 into retina, 376 into vitreous, 61, 345 a cause of amaurosis, 402 Herpes of the conjunctiva, 227 of the cornea, 238 frontalis, 193 zoster ophthalmicus, 193 Hexagonal pigment cells of retina, 6, 8,374 Hippns, 285 Hieronymous diplopia, 106 Holmgren's test, 24 Homatropine, 47, 98 hydrobromate of, 45 solution of, 47 Homonymous diplopia, 105 Hops, decoction of, 45 Hordeolum, 172 Hot applications, 45 Hotz's operation for trichiasis, 184 Hutchinson's teeth, 250 Humors of eye, 4 Hyalitis, 342 Hyaloid artery, persistent, 346 body, 341 diseases of, 342 canal, 341 fossa, 341 membrane, 4, 8, 341 Hyaloidea, 4, 341 Hydatids in orbit, 142 Hydrocephalus, 133 Hydrophthalmus, 266 Hydrops nervi optici, 398 Hyoscyamine, 46 Hypaemia (blood in anterior cham- ber), 58 Hyperaemia of conjunctiva, 199 of choroid, 350 of iris 270 of optic nerve, 396 of retina, 375 Hypersesthesia of the cornea, 239 retina, 386 Hypermetropia, 75, 76 absolute, 80 Hypermetropia, acquired, 76 asthenopia in, 77 divergence of visual axes in, 104 diagnosis of, 76, 78 facultative, 80 a frequent cause of asthenopia, 77 of convergent squint, 119 latent, 79 manifest, 79 ophthalmoscopic diagnosis of, 78 original, 76 relative, 80 symptoms, 77 treatment of. 81 Hypermetropic eye, 81 Hypermature cataract, 324 Hyperopia (vide Hypermetropia.) Hyperopic astigmatism, 94 Hypopyon, 245, 253 Hysterical amblyopia, 403 hyperassthesia of the retina, 386 ICE bag, 44 Ice, use of, 44 . Ideas of solidity, 17 Illumination, focal, 28 oblique, 28 Images, actual, of fundus oculi, 36 virtual, of fuudus oculi, 34 Immature cataract, 324 Incipient cataract, 324 Inferior oblique muscles, 9 paralysis of, 110 recti muscles, 9 paralysis of, 109 Infinite distance defined, 64 Inflammation of choroid, 349 ciliary body, 293 conjunctiva, 200 cornea, 238 eyelids, 169 globe, suppurative, 60, 355 iris, 270 and choroid, and ciliary body, 294 lachrymal gland, 152 sac, 162 optic nerve, 397 orbit, cellular tissue of, 133 retina, 378 sclerotic, 264 vitreous humor, 342 whole eye, 355 Infra-orbital groove, 130 Injection of ciliary vessels, 23 of ciliary zone, 23 Injuries of the eye, 50 of the ciliary region, 295 conjunctiva, 52 cornea, 54 INDEX. 417 Injuries of the globe from gunpow- der, 53 iris, 59 lachrymal apparatus, 62 lens, 59 lids, 49 orbit, 50 retina, 63 sclerotic, 57 sympathetic ophthalmia from, 303 vitreous, 61 Inoculation for pannus, 226 granulated lids, 225 Insects, bite of, 169 Instruments, 47 Beer's knife, 49 fixation forceps, 49 foreign-body hook, 62 iris forceps, 286 gouge, 55 iris scissors, 289 keratome, 286 lid elevators, 47 linear cataract knife, 286 scoop, 335 specula, 48 spud, 55 wire scoop, 336 Insufficiency of recti externi, 113 recti interni, 113 Internal rectus muscle, 9 insufficiency of, 113 paralysis of, 109 tenotomy of, 123 weakness of. 113 treatment of, 114 Inter-cerebral fibres. 394 Inter-retinal fibres, 394 Inter-vaginal space, 9, 394 Intra-cranial disease. 397 Intra-ocular tension, 6 tumors, 282, 356, 390 Inversion of lid, 183 Inverted image, 36 Investing membranes, 4 Involuntary oscillations of globe, 129 Iridectomy, 61, 285 in cataract, 334 in conical cornea, 260 in corneal opacities, 285 in glaucoma, 369 in iritis, 276 indications for performance of, 285 in lamellar cataract, 320 Irideremia, 282 Irido-choroiditis, 351 sympathetic, 59 treatment, 351 Irido-cyclitis, 294 Iridodesis, 290 mode of performing, 290 Iridodialysis, 290 Iridotomy, 289 Iris, 4, 7 absence of, congenital, 282 adhesions of, 272 anatomy of, 7, 268 angle of, 12 cancer of, 282 coloboma of, 282 color of, 22 congenital malformations, 282 contraction of, 284 cysts of, 282 detachment of, 58 dilatation of, 283 diseases of, 270 to examine, 22 foreign bodies in, 58 functional troubles of, 283 hernia of, 56, 244 hyperaemia of, 270 inflammation of, 270 injuries of, 57, ligamentum pectinatum of, 237 movements of, 269 muscles of, 269 operations on the, 285 prolapse of, 56, 244 tremulous, 59 tumors of, 282 wounds of, 57 Irish race, 221 Iritis, acute, 270 causes of, 271 chronic, 274 gonorrhoeal, 271 idiopathic, simple, 270 parenchymatous, 280 plastic, 280 serous, 278 spongy, 282 suppurative, 281 sympathetic, 302 syphilitic, 271 traumatic, 271. treatment of, 274 Ischaemia retinae, 375 Iwanoff, 78 on ciliary muscle, 78 JAEGER, test types of, 88 Jequirity, 225 Jones, Wharton, operation for ectro- pium, 187 KERATITIS, 238 diffusa, 249 fascicularis, 239 interstitial, 249 418 INDEX. Keratitis, nenro-paralytic, 256 parenchymatous, 249 phlyctenularis, 238 punctata, 256 pustulosa, 235 euppurativa, 253 ulcerosa, 242 vasculosa, 252 Keratocele, 247 Kerato-cornus, 259 Kerato-globus, 261 Kerato-iritis, 242 Keratoscopy, 39, 89 Knapp's clamp forceps, 174 foreign-body hook, 62 knife, 158 plastic lid operation, 189 Knife, Agnew's, 158 Be.er's, 49 Knapp's, 158 Noyes', 158 Selling's, 158 Kuhne, investigations of visual purple, 17 LACERATION of conjunctiva, 52 of choroid, 63 of lids, 51 Lachrymal abscess, i62 apparatus, 150 anatomy of, 150 diseases of, 150 injuries of, 52 canal, 151 obstruction of, 156 stricture of, 156 canaliculus, 151 slitting the, 154 caruncle, 150 duct, 2 fistula, 162 gland, 2, 150 accessory, 152 diseases of, 152 extirpation of, 153 fistula of, 152 functional diseases of, 153 hypertrophy of, 152 inferior, 150 inflammation of, 152 tumor of, 153 groove, 130 punctum, 2, 151, 167 eversion of, 154 mal-position of, 154 occlusion of, 154 obliteration of, 154 papilla, 167 probes, 159, 161 sac, 151 abscess of, 162, 164 Lachrymal sac, degeneration of, 164 blennorrhoea of, 164 extirpation of, 161 fistula of, 162, 164 inflammation of, 162 obliteration of, 161 stricture, 154, 158 causes, 155 Stilling's operation for, 158 symptoms, 156 syringe, 161 Lachrymation, 153 varieties, 156 treatment, 156 electrolysis in, 160 Lacus lachrymalis, 150 Lagophthalmos, 191 Lamina cribrosa, 5, 13, 394 fusca, 13, 263 Laminated cataract, 319 cells of retina, 8 Lateral dislocation of lens, 340 illumination, 28 Layer of rods and cones, 8, 373 Lead amblyopia, 403 deposits on cornea, 258 a cause of nerve atrophy, 401 LeBrun's operation for cataract, 337 Lens, 4, 16 crystalline, anatomy of, 311 absence of, 340 diseases of, 313 dislocation of, 59, 60, 340 focal length of, 65 foreign bodies in, 60 injuries of, 59 operations upon, 316, 318, 330 physiological changes in, 72 wounds of, 60 Lenses, optical properties of, 64, 65 concave, 65, 69 convex, 64, 69 cylindrical, 69 forms of, 70 kinds of, 68 prismatic, 70 spherical, 69 stenopaic, 70 Lenticular cataract, 315 Leptothrix, 155 Leucomata, 257 Leucoma adherens, 247, 257 totalis, 257 Leucorrhoea, 210 Levator palpebrse, 9, 167 paralysis of, 190 Lice on eyelashes, 175 Lid elevators, 47 Lids (vide Eyelids) Liebold's syringe, 45 INDEX. 419 Liebold on use of mere, nit., 229 Ligament, suspensory, 7, 16 Ligamentum pectinatum, 12, 237 Limbus conjunctivas, 197 Limiting membrane, 6 Lime, burns by, 53 treatment of, 53 Lime water and oil, 52 Linear extraction of cataract, 318 Lipomata, 142 Liebreich's operation for cataract, 337 opththalmoscope, 31 Light streak on retinal vessels, 38 Listing, diagrammatic eye of, 14 Locomotor ataxy, a cause of optic nerve atrophy. 401 Long ciliary arteries, 10 uerves, 9, 10 Long sightedness (vide Hypermetro- pia) Loring, 29, 31 on relation of axis to degree of myopia, 8 Loring's ophthalmoscope, 32 Lotions, disinfecting, 45 Lupoid growths on lids, 193 Lupus of conjunctiva, 234 of lids, 193 Lymph space, 6. 9, 13 of optic nerve, 13, 394 Lymphatics, 11 of eyeball, 12 Lymphoid infiltration of conjunctiva, 226 MACULA of the cornea, 257 Macula lutea, 8, 17, 24 ophthalmic appearance of, 39, 375 to examine, 38 Madarosis, 175 Magnet, Gruening's, 63 Malignant glaucoma, 370 pustule of eyelids, 171 tumor of orbit, 142 Malposition of lids, 183, 186 Mariotte, blind spot of, 17, 389 Mariotte's experiment, 17 Mature cataract, 324 Measles, 122, 202, 239 Measure, linear, of squint, 121 Meckel's ganglion, 131 Medicine dropper, 46 Medullary carcinoma of choroid, 356 of orbit, 142 Megalophthalmos (vide Hydropthal- mus) Megalopsia, 353 Meibomian cysts, 173 glands, IG8 anatomy of, 16 Meibomian glands,inflammation of ,173 calcareous deposits in, 231 Melanoma of cornea, 261 of orbit, 356 Melanotic cancer of choroid, 356 of orbit, 142 Membrana chorio-capillaris, 348 hyaloidea, 8, 341 limitans, 6, 373 nictitans, 196 Membrane, posterior elastic, 5 anterior elastic, 235 i of Descemet, 12, 235, 237 hyaloid, 8 limiting, 6 Membranous cataract, 339 Meningitis, 133 a cause of muscular paralysis, 108 cerebro-spinal, a cause of panoph- thalmitis, 355 Meniscus, negative, 69 positive, 69 Menses, suppression of, a cause of capsulitis, 139 Mercury, ointments of, 176 Meridians of eye, 4 horizontal, 4 principal, 4 vertical, 4 Metamorphopsia, 88, 353 Methods of examination, 19 Micropsia, 353 Miliary trachoma, 226 Military ophthalmia, 220 Milium, 194 Milky cataract, 315 Mixed astigmatism, 94 cataract, 321 | Mobility of the eye, to examine. 20 Moles on the lids, 194 Molluscum, 194 Monocular polyopia, 93 Morgagnian cataract, 324 Mortar, injuries from, 53 treatment, 53 Mucocele, 156, 164 Muscse volitantes, 87, 343 Muscles of the eye, 9 anatomy of, 101 action of, 102 affections of, 101 conjugate, 104 Muscle of accommodation, 7, 291 annular of Mueller, 292 ciliary, 7, 9, 291 diseases of, 295 tendo oculi, 151 tensor taris, 151 rectus externus, 9, 101 paralysis of, 110 inferior, 9, 101 420 INDEX. Muscles of the eye, paralysis of, 109 rectos interims, 9, 101 paralysis of, 109 superior, 9, 101 paralysis of. 109 inferior oblique, 9, 101 paralysis of, 110 superior oblique, 9, 101 paralysis of, 9, 101 ring, 7 orbicularis palpebrarum, 3, 168 spasm of, 192 sphincter of ciliary body, 7 of iris, 9 testing strength of, 192 extrinsic, 101 intrinsic, 101 internal, 101 external, 101 yoked, 104 Muscular asthenopia, 77, 92, 113 causes, 114 symptoms, 114 diagnosis, 115 test, 115 treatment, 115 insufficiency, 113 paresis, 113 paralysis, 107 causes, 108 symptoms, 108 diagnosis, 109 treatment, 111 Mydriatics, 45 atropine, 46 duboisia, 46 homatropine, 46 Mydriasis, 283 Myopia, 83 causes, 84 convergence of visual axes in, 104 diagnosis, 88 length of optic axis in, 85 pathological changes in, 86 prognosis in, 92 relation of axis to degree of, 85 treatment of, 89 simulated, 81 symptoms, 88 Myopic eye, 90 astigmatism, 97 crescent, 87 eye, pathological changes in, 86 Myosis, 284 Myotics, 45 eserine, 47 pilocarpine, 47 NfflVUS of lids, 194 Narcotics, use of, 193 Nasal catarrh in lachrymal trouble, 165 Nasal duct, 151 exploration of, 157 stricture of, 156 treatment, 158 Near point, 71, 73 Near-sightedness (vide Myopia) Nebulae of cornea, 257 Necrosis of orbit, 139 Negative accommodation, 72 Negroes, 221 Nephritic retinitis, 380 Nerves of eye, 9 fifth, ophthalmic division of, 9 fourth, 9 long ciliary, 10 - optic, 9 atrophy of, 24 sixth, 9 third, 9, 10 paralysis of, 110 Neuralgia ciliaris, 272 Neuritis, 95 Neuritis optica, 397 descendens, 398 Neuro-paralytic affection of cornea, 256 Neuro-retinitis, 378 diagnosis of, 378 Neurosis, sympathetic, 302 ef fifth nerve, 363 Nictitation, 192 Night-blindness, 388 Nitrate of silver, 174 Nodal point, 66 Node, syphilitic, 145 Nomenclature of glasses, 67 Normal eye. defects of, 16 Noyes' operation for canthoplasty, 186 speculum, 47 knife, 158 Nuclear cataract, 322 Nyctalopia, 388 Nystagmus, 129 OBJECTIVE examination of the eye, 20 Oblique illumination, 28 muscles, 102 functions of, 102 Obliteration of lachrymal sac, 1C1 of pupils, 280 Obstruction of lachrymal passages, 156 Occipital lobes, 8 Occlusion of pupil, 280 Ocular sheath, 2, 13, 101, 132 inflammation of. 139 muscles, paralysis of, 107 INDEX. 421 Ocnlar muscles, paralysis of, causes, 108 symptoms, 108 Ocnlo-orbital fascia, 168 f-*^/ . - -'. 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