DISEASES OF THE CORNEA 411 



of the ulcer is very small the anterior chamber fills up again, is forced 

 forward, forming a clear bladder-like body, forming corneal prolapse or 

 dropsy of the cornea (keratocele). If the ulcer is large, the membrane of 

 Descemet pushes throvigh the ulcer from internal pressure and the whole 

 ground of the ulcer becomes embossed — that is, it stands out from the 

 surrounding membrane. As a consequence of perforation of the cornea 

 we may have a series of alterations to the iris. Externally the iris, 

 which is drawn into the orifice, becomes covered with cicatricial tissue, 

 and by its contraction forms a lobule of the iris. This finally contracts 

 into a peculiar club-shaped body over the anterior surface of the mem- 

 brane (iris staphyloma), ^^'e must not confound this condition with 

 staphyloma pellucidum, by which we mean a change of form in the 

 corneal membrane, due to a non-inflammatory condition, where 

 it becomes more or less opaque and is forced outward in the shape of a 

 grape-like body by the dropsical condition of the anterior chamber. 

 "When there is great irritation of the corneal membrane, in some cases 

 we ma}' have a prolapsus of the lens, and the whole eye]:)all subsequently 

 collapses, forming an opening in the centre of the eye which finally 

 becomes closed up by a whitish-gray cicatrix. 



Besides the causes alread}' mentioned in the formation of abscesses, 

 the following also produce them: cauterization, foreign bodies which 

 adhere to the membrane, wounds in some cases, etc. This disease 

 may appear in the epizootic form with or without distemper, and gen- 

 erally in connection with blcnnorrhoea of the whole eyeball (purulent 

 panophthalmitis) . 



Prognosis and Therapeutic Treatment, — The prognosis depends to a 

 large extent on the irritation of the ulcer and the rapidity of its progress. 

 Ulcers which are small and located on the borders are easier to treat 

 than those which are larger and located in the centre of the cornea. In 

 weak, badly fed young animals and in pugs the prognosis is more un- 

 favorable than in healthy adult animals. 



The treatment requires cleanliness and strict antiseptic remedies. 

 The use of a dressing is of great advantage, but few dogs can be made to 

 submit to one. In canine hospitals, as a rule, they use a specially 

 constructed leather cap; it is not to be used except in extreme cases, 

 where it is impossible to keep the animal from scratching or rubbing the 

 eye. It is always well to leave the affected eye without covering, as all 

 bandages or covei'ings are apt to press on the eye and cause intense 

 pain, which irritation the animal generally increases by rubbing or pulling 

 constantly at the covering. The various antiseptic agents which are 

 used are corrosive sublimate, 1 to 2000, or chlorine water (either pure or 

 mixed with two or three parts of water), to be applied with a brush and 

 calomel powder blown from a ciuill directly on the eye. The writer has 



