Acute Keratites. Inflammation df the Cornea. 381 



cicatrix or opacity. Lesions : exudates of lymph and leucocytes into cor- 

 neal layers: embryonic tissue vascularization: abscess: ulcer: cicatrix: 

 opacity : staphyloma : hypopion : prolapsus iridis : panophthalmia. Treat- 

 ment : antiseptic astringents, atropine, leeching, derivatives, blister, seton, 

 , opacities ; in severe cases antiseptic puncture, sublimate lotion, silver 

 nitrate, potassium permanganate, boric acid, pyoktanin : in perforations 

 antiseptic bandage and eserine, iridectomy : in chronic cases mercury oxide. 



Keratitis occurs in all domestic animals as a primary disease, or 

 as an extension from conjunctivitis. 



Causes. Extension from acute, enzootic, infections conjuncti- 

 vitis in sheep and cattle has been noticed by a great number of 

 observers. Bayer and lyOhofEhave studied maculated keratitis of 

 the superficial layers in horses. Again it has followed wounds by 

 foreign bodies, spikes of vegetables, particles of iron and glass, 

 blows of whips, or insects, stings, etc. It also occurs in con- 

 nection with the local action of particular poisons, such as variola 

 (foot and mouth disease), canine distemper, etc., and from the 

 local irritations caused by trichiasis or entropion or by the filarise 

 lachrymalis (ox) and palpebralis (horse). 



Symptoms. The eye is extremely sensitive, and habitually 

 closed, with a profuse flow of tears, and a disposition to resist 

 opening of the lids. When exposed the cornea is seen to be 

 more or less clouded and perhaps reddened by the formation 

 of vessels proceeding from its sclerotic margin. This is known 

 as pannus. If the anterior chamber is still visible the pupil is 

 found to be contracted showing photophobia. The congestion 

 is first visible in the sclerotic and in the absence of pigment 

 is most intense near the margin of the cornea. Upon the cor- 

 nea itself it is preceded by a deep white opacity, into which 

 the vascularity gradually extends. The whole cornea may finally 

 become of a bright pink hue. 



The congestion of the cornea may advance to fibrinous exuda- 

 tion, or the formation of pus between its layers, to molecular 

 degeneration and the formation of ulcer,, or even to perforation 

 and escape of the aqueous humor. In this case prolapsus iris, 

 panophthalmia and destruction of the eye are likely to ensue. 



Ulcer if not readily seen with unaided vision can be easily 

 recognized by the aid of focal illumination, and abscess can be 

 detected by the presence of a sharply circumscribed centre of in- 



