268 



TUMORS OF THE EYEBALL. 



A variety of tumors attack the eyeball — dermoid, papillary, fatty, 

 cystic, and uielauotic, but perhaps the most frequent iu the horse is 

 encephaloid cancer. This may grow in or on the globe, the haw, the 

 eyelid, or the boiies of the orbit, and is only to be remedied if at all by 

 early and thorough excision. It may be distinguished from the less 

 dangerous tumors by its softness, friability, ami great vascularity, 

 bleeding on the slightest touch, as well as by its anatomical structure. 



STAPHYLOMA. 



This consists in a bulging forward of the cornea at a given point by 

 the saccular yielding and distension of its coats, and it may be either 

 transparent or opaque and vascular. In the last form the iris has 

 become adherent to the back of the cornea, and the whole structure 

 has become filled with blood-vessels. In the first form the bulgingcoruea 

 is attenuated ; in the last it may be thickened. The best treatment is 

 by excision of a portion of the iris so as to relieve the intra ocular 

 pressure. 



PARASITES IN THE EYE. 



Acari in the eye have been incidentally alluded to under inflammation 

 of the lids. 



The Filaria lachrymalis is a white worm, one-half to 1 inch long, which 

 inhabits the lachrymal duct and the under side of the eyelids and haw 

 iu the horse, producing a verminous conjunctivitis. Tlie first step in 

 treatment in such cases is to remove the worm with forceps, then treat 

 as for external inflammation. 



The Filaria papiUosa is a delicate, white, silvery-looking worm, which 

 I have repeatedly found 2 inches in length. It invades the aqueous 

 humor, where its constant active movements make it an object of great 

 interest, and it is frequently exhibited as a "snake iu the eye." It is 

 found also iu other internal cavities of the horse, to which it undoubt- 

 edly makes its way from the food, and especially the water swallowed, 

 and its prevention is therefore to be sought mainly in the supply of 

 IKire water from close deep wells. When present in the eye it causes 

 inflammation and has to be removed through an incision made with 

 the lancet iu the ut)per border of the cornea close to the sclerotic, the 

 point of the instrument being directed slightly forward to avoid injury 

 to the iris. Then ajiply cold water or astringent lotions. 



The echinococcm, the cystic or larval stage of the echinococcus tape- 

 ■worra of the dog, has been found in the eye of the horse and acysticer- 

 cus {Gysticercus Jistularis ?) is also reported. 



The Pentastoma tfenioides, which inhiibits the nose of horse and dog, 

 has been found by Stitteu in the eye of the horse, but the case is 

 unique. 



