Aaite Keratitis. Inflavimation of the Cornea. 379 



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

 neal la3-ers : embryonic tissue : vascularization : abscess : ulcer : cicatrix : 

 opacity : staph3'loma : 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, pyoktannin : in perforations 

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



Keratitis occiir.s in all domestic animals as a primary disea.se, or 

 as an extension from conjunctivitis. 



Causes. Extension from acute, enzootic, infectious conjuncti- 

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

 observers. Bayer and lyohoflf have studied maculated keratitis of 

 the superficial layers in hor.ses. Again it has followed wounds by 

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

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

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

 (foot and mouth disease), canine distentper, 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 habituall}^ 

 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 

 2ls paniuis. 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 mo.st intense near the margin of the cornea. Upon the cor- 

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

 the va.scularity 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 ca.se 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 sharplj' circumscribed centre of in- 



