AMAUROSIS. 1 1 7 



nerve and its terminal expansion, the retina, without there 

 being much change in the appearance of the eye itself. 

 Occasionally it coexists with cataract, and also with periodic 

 ophthalmia. It also occurs sometimes as a symptom of 

 certain diseases, as parturient apoplexy in the cow, and 

 in the last stages of other diseases. It may be caused by 

 injuries to the optic nerve, resulting from blows on the 

 head, or standing in very dark stables for a long time — for 

 this reason horses after being down a coal-pit for a 

 lengthened period become blind. It may be very quickly 

 developed, and has been noticed as a result of haemorrhage, 

 and more particularly of secondary haemorrhage. Amaurosis 

 has often been noticed to occur in pregnant mares ; in such 

 cases it comes on a few days before foaling, and as a rule spon- 

 taneous recovery takes place w^ithin a few days after foaling. 



Symj^toms. — The principal symptom is the abnormally 

 dilated condition of the pupillary opening, which loses its 

 elliptical form and becomes round. The eye is prominent, 

 bright, and has a peculiar glassy appearance. The vision 

 is found to be impaired or totally lost ; generally both eyes 

 are affected simultaneously, except in cases where amaur- 

 osis is due to an injury affecting but one eye. The animal, 

 when trotted out, steps along with an unnaturally high 

 action, and carries his head in a peculiar position. Hence 

 the name ' star-gazer ' that is sometimes applied to such 

 horses. The animal is very sensitive to sounds, pricking 

 up his ears at the slightest noise. The pupillary opening 

 fails to contract on sudden exposure to light. 



Treatment. — If the case be undertaken at an early stage, 

 the administration of nerve stimulants is to be tried, as 

 nux vomica, or its alkaloid. A purgative, followed by 

 diuretics, may be tried also. Potassa3 bromide is some- 

 times useful in the early stages. Vesication or electricity 

 may be tried, but as a rule it is incurable. 



