410 DISEASES OF THE EYES 



toward the anterior chamlier of the eye, causing an accumulation of pus 

 in it (hypopyon) and producing further infiammatoiy processes in the 

 internal part of the eyeball. 



Therapeutics. — This is closely related to that of ulcerations of the 

 cornea — that is, to open, puncture, or cauterize the abscess after first 

 using cocaine in the cornea. It is then dried with corrosive suljlimate 

 or iodoform gauze antl washed out with a solution of corrosive subli- 

 mate, and afterwards dusted with calomel until it dries up; in certain 

 cases touching the edges with the actual cautery seems to bring about 

 jjrompter resolution. 



(4) Ulceration of the Cornea. — Ulcus Comeae. — This results from 

 traumatisms, irritations, and an accompaniment of distemper; it also 

 appears in diabetes mellitus and certain breeds, such as toy spaniels and 

 Boston terriers, seem to be prone to it, with no appreciable cause; ap- 

 parently it is due to a certain cachexia and after maceration or necrosis 

 of the corneal epithelium, as a consequence of blennorrhoea of the cornea. 

 In this condition we find a loss of substance in the cornea which vaiies 

 in size and depth, showing a grayish-white or grayish-yellow ground, and, 

 as a rule, has short, abrupt liorders with a bluish-gray, gray, or grayish- 

 yellow opacity in the immediate neighborhood of the ulceration and 

 accompanied by great dread of light; the eyelids are practically closed 

 and the membrana nictitans drawn over the eye. "When the ulceration 

 of the cornea begins to heal it is indicated by a lessening of the infiltra- 

 tion in the immediate neighborhood of the ulcer, the dull circle sur- 

 rounding it becomes clearer, the pericorneal injection less, and the 

 dread of light begins to disappear. In rare instances blood vessels 

 will shoot from the edge of the cornea toward the ulcer, and the cornea 

 in appearance very much resembles the normal tissue of the sclerotic 

 membrane. If the ulceration has not been veiy deep, the dulness 

 gradually disappears, leaving only a very thin white veil of opacity; or, 

 if the ulceration is deep, we have as a result a distinct white spot which 

 remains permanently (cicatrix of the sclerotic membrane, macula cornea). 

 This cicatrix of the membrane may become clearer in the course of time, 

 but, as a rule, it never disappears entirely. AMien the ulcer does not 

 take a favorable termination we find the inflammation increases, the 

 ulceration becomes deeper, reaches the membrane of Descemet, and we 

 have a perforation of the meml)rane in a few days. The contents of the 

 anterior chamber escape through the opening, and in rare instances 

 the iris and the lens push forward and maj' also protrude if the opening 

 is large enough. After jiorforation occurs the ulcer begins to heal, and 

 we are very apt to have an adhesion of the iris and lens to the posterior 

 wall of the corneal membrane, the pupil is drawn to the edge of the 

 cicatrix and the sight greatly impaired. In othei- cases where the opening 



