GLAUCOMA. 127 



together with the vitreous humour. Under what especial con- 

 ditions tlie eye under ophthahnia takes this glaucomatous turn — 

 which still mostly ends in cataract — rather than proceed to the 

 formation of cataract at once, I am not at this time prepared to 

 explain. 



The Glaucoma of Age is seldom to be discovered but in very 

 old horses, and not in all instances among them. As age advances, 

 the pupil, naturally sluggish in the horse's eye, becomes still more 

 so ; its contractions and dilatations, from the presence or absence 

 of light, are less remarkable ; in fact, become so tardy and incon- 

 siderable as often to be unobservable. At the same time, the pupil 

 is found to have acquired quite a grey blue aspect, and in some 

 aged subjects, in certain lights, will appear of a greenish hue. 

 These changes are, no doubt, in part attributable to alterations in 

 the consistence and colour of the lens ; but the vitreous humour 

 will, I believe in most cases, be also found in an altered condition, 

 a circumstance that authorises us to consider the disease as one of 

 a glaucomatous nature. 



The Pathology of glaucoma, in its pure or uncomplicated 

 form, appears, from the observations of eminent human oculists, to 

 consist in disease and ultimate absorption or solution of the hyaloid 

 membrane, leaving the vitreous humour in the same unconfined 

 fluid condition as that in which the aqueous humour naturally 

 exists. It is thought, so far as disease is concerned in such a change, 

 that inflammation is the producer of this ; and veterinary observa- 

 tion appears confirmatory of this opinion. With the glaucoma 

 of age, however, we apprehend inflammation can in no way be 

 concerned. Sooner or later, in all cases almost, these changes in 

 the lens and vitreous humour are succeeded by disorganization of 

 the retina, rendering the eye less susceptible of the impressions of 

 light ; and, in the end, so little so as to make the organ appear, 

 or really be, in a state of amaurosis. 



Remedies for Glaucoma, the result of disease, are all, as a 

 matter of course, merged in those for periodic ophthalmia. The 

 glaucoma of age admits of no relief. 



