DISEASES OF THE CORNEA 409 



or gray, rarely grayish-white, either covering the entire cornea or only 

 certain portions, accompanied by watery eyes, sensitiveness to light 

 (but only to a slight degree), and also the formation of new vessels 

 which extend from the borders of the cornea toward the centre. In the 

 keratitis of distemper the opacity covers the entire eye, and is blue-gray 

 or even milky in color. Abscesses and ulcerations, as a rule, are rare. 

 This form, however, must not be mistaken for ulcerative keratitis. In 

 mild cases the opacity may disappear without leaving any trace; in 

 more severe cases it may run a protracted course, with vascular infiltra- 

 tion from the border of the cornea. These cases are very difficult to 

 treat, running on sometimes for months and at times resist all forms 

 of treatment, in some cases terminating in ulceration (see Keratitis). 



The course of this disease is generally favorable. After several 

 weeks the dulness disappears and the new vessels become thinner, dis- 

 appearing entirely in a short time. 



Therapeutics. — We attempt to remove the irritation to a certain 

 extent by applications of compresses. Also irrigate with warm w^ater or 

 boric acid, and drop atropia into the eyes. Bandages over the eyes. 

 If the inflammatory symptoms are reduced, we then follow it up by 

 stimulant irritants, such as calomel powder or ointments of red oxide 

 of mercury. As to massage of the cornea and treatment of ulceration see 

 Keratitis. 



(3) Abscesses of the Cornea. — Etiology. — Abscesses of the cornea 

 appear after some traumatism, especially contusions or bruises of the 

 membrane, also after non-septic operations, in connection with blennor- 

 rhoea or conjunctivitis, or during distemper, and very frequently appear 

 without any appreciable cause, which some ascribe to lymphatic in- 

 fection. 



When there is intense dread of light and great increase of tears, 

 and when we see a pericorneal injection and the cornea colored a gray, 

 yellow, or straw-yellow, and a certain spot on that part which is sharply 

 defined from the tissue of the normal cornea, or it is surrounded by a 

 more or less dull zone, we then can safely conclude that it is the com- 

 mencing formation of an abscess. Its location varies; sometimes it is 

 on the edge of the cornea, at other times in its centre; then, again, we 

 may find it close to the surface of the membrane or deep in the centre of it. 

 It may be very small in dimension, such as the size of a pin-head, or it 

 may even include the whole sclerotic membrane. 



The course varies also. In small abscesses it may disappear by 

 simple absorption, while in large ones the acute inflammation subsides, 

 frequently leaving an intensely white spot, or it may break out exter- 

 nally, forming an open ulcer. This latter conclusion, or termination, is the 

 most common, and in rare instances it may break in a posterior direction 



