PERIODIC OPHTHALMIA. 559 



have endeavoured to combat it. It is very true that the in- 

 flammatory stage is seemingly modified and cut short by various 

 remedies ; but the disease recurs, and terminates only when the 

 sight is completely destroyed. Some writers affirm that when it 

 attacks both eyes alternately it is better to destroy the one and 

 save the other — that when one is destroyed it occurs no more. 

 Surely this is a mistake. I have over and over again seen it 

 attack one eye repeatedly until cataract was completely de- 

 veloped, then attack the other until the same result was produced. 



An acute attack is always accompanied by febrile disturb- 

 ance; to relieve this a purgative is useful, to be succeeded by 

 febrifuges, such as the nitrate of potash, aconite ; and, meting 

 upon the knowledge that effete materials are circulating in the 

 system, colchicum may be given with advantage. The local pain 

 is to be soothed by fomentations, anodyne collyria and belladonna, 

 but no irritatincp materials should be made use of. 



Prevention is of greater importance than attempts to cure 

 what has already proved itself beyond the reach of any and every 

 known remedy. 



Horses subject to this disease continually change owners ; 

 and, as a legal question, the ability to discriminate between the 

 healthy and unsound eye becomes a matter of great importance 

 to the veterinarian ; and Mr. Percivall says, very correctly — 

 " Any single one of the following appearances may, unless its 

 origin can be satisfactorily traced to simple ophthahnia, excite 

 our suspicions ; but a combination will warrant an unfavourable 

 prognostic : — ^A sunken or gloomy aspect of the eye altogether, 

 compared with the other ; prominence of the membrana nictitans ; 

 vascularity or pinkness of the conjunctiva; a watery state of 

 the eye; dimness or cloudiness of the cornea, particularly 

 around its margin ; dulness or discoloration of the iris ; corpora 

 nigra yellowish, whitish, or spotty ; pupil smaller than the other ; 

 perhaps hazy or milky, or containing a minute white speck in 

 its centre, which is an incipient cataract." 



Another symptom, and one of great importance, wliich Mr. 

 Percivall does not notice, is the wrinkled or furrowed appearance 

 of the upper lid and eyebrow. 



The common termination of periodic ophthalmia, viz., 

 cataract, is a very important subject to consider in its medico- 

 legal aspect. 



