126 GLAUCOMA. 



pointed stilette*, is another instrument he employs ; a small double- 

 branched crochet or blunt hook, a third; an elevator, a fourth. For 

 a description of these several instruments, and for an account of his 

 method of operating — in which he has followed the rules laid down 

 by Scarpa — and for all other particulars, we must refer those who 

 may feel disposed to experimentalize on this branch of veterinary 

 surgery to Leblanc's Traite des Maladies des Yeux, a work replete 

 with every kind of information on the subject. 



GLAUCOMA. 



Glaucoma — a derivation from the Greek word yXuvKog, signi- 

 fying of a blue colour — is the term used in medicine to denote an 

 unnatural green appearance of the interior of the eye. Human 

 surgeons, acute observers in their own practice, are very apt, from 

 ignorance of the structure and aspect of the eyes of animals, to 

 suspect horses' eyes of being cataractous or glaucomatous when, 

 in reality, they are perfect specimens of health : being deluded by 

 the reflection of the tapetum lucidum. 



The Horse, it appears to me, is the occasional subject of glau- 

 coma in one of two forms : either as an attendant or sequel of cer- 

 tain states or stages of periodic ophthalmia, or as an accompani- 

 ment of old age. D' Arboval denies that glaucoma is ever an especial 

 disease ; but regards it as one of the symptoms of periodic oph- 

 thalmia, or " some other ocular disorder." 



The Glaucoma of Ophthalmia is that recognisable change 

 the eye undergoes in the course of the periodic disease which 

 commonly goes by the name of green cataract : the aspect of the 

 organ to the close and intelligent observer is such as to assure him 

 that the case is not one of genuine cataract ; for he can plainly see 

 through the lens, changed in colour though it be, to the very bottom 

 of the eye, the pupil the while remaining dilated, almost or quite 

 insensible to light, and the organ altogether being in a state ap- 

 proaching amaurosis. The reflection from the bottom of the eye is 

 not so much green as yellow, or rather amber-colour, a circum- 

 stance owing to the participation of the crystalline body in disease, 



* A triple-branched or tricuspid stilette is very useful in the absence of 

 an expert assistant. 



