I 



DISEASES OF THE EYE. 263 



here both exciting and predisposing causes. A weakness of the 

 structure of the eye is often derived from the parents, and the 

 causes above-mentioned soon bring on disease. 



Specific oplithahiiia usually makes its appearance between 

 the fourth and seventh year, but sometimes before, and occasion- 

 ally in old horses. 



Harness horses are certainly more liable to the disease than 

 those used for the saddle alone ; and horses with a small sunken 

 eye are more likely to be affected than those with full open eyes. 

 The disease is also more likely to occur amongst coach and post 

 horses, where a number are kept together, than amongst gentle- 

 men's studs. 



Treatment. — Although different parts of the eye may be 

 affected, yet the attack being one of inflammation, the treat 

 ment should be pretty much the same in all cases, and should 

 consist, in the first place, of local and general bleeding and 

 physic, as advised for simple ophthalmia ; the bleeding should 

 be rejieated as required ; warm fomentations should be used at 

 first, and should be succeded by the cold lotion before advised, 

 or the following, which is more stimulating : — 



Sulphate of zinc 1 drachm. 



Superacetate of lead 4 scruples. 



Water 1 pint. 



Mix, and, after shaking them together, filter through blotting 

 paper. 



When the inflammation has in some measure subsided, a seton 

 may be inserted under the eye, and kept in for several weeks. 



Some persons object to the seton, on account of the mark it 

 leaves for some time, and recommend instead one to be placed 

 vmder the jaws. 



A few drops of wine of opium may be daily insinuated Into 

 the eye, or the nitrate of silver lotion prescribed in the preceding 

 article. 



A variety of stimulants have been applied to the eye with 

 advantage, and it is often necessary to vary them, as they some- 

 times lose their effect by repetition. A solution of the extract 

 of belladonna, as well as that of digitalis, has been found very 

 useful ; and sometimes a stimulant in the form of an ointment 

 has been most convenient and effectual, such as the ointment of 

 nitrated quicksilver, weakened by mixture with one half the 

 quantity of lard, and applied to the eyelids once a day ; or an. 

 ointment composed of one part of sulphate of zinc and sixteen 

 parts of lard.* 



It is of importance that the horse should be removed to a 



* For other medical applications for the eye refer to the Materia Medica. 



s 4 



