WORM IN THE EYE. 345 



it is the immature (unmarried) form of the filaria equina {filaria 

 papulosa), which is sometimes found in the peritoneal cavity 

 (p. 114) of horses. This disease is rarely met with, except in 

 India, where it is frequently seen in some districts. 



SYMPTOMS.— The first sign of the worm is a slight dimness 

 or milky appearance of the cornea, which is due to inflammation 

 caused by the presence of the worm; and beneath the cornea the 

 parasite may often be seen moving about in the anterior chamber 

 of the eye. Not unfrequently, while the eye remains moderately 

 clear, the wonn suddenly disappears, and then, after some time, 

 comes into view again. In such a case, it inserts itself, for the 

 time being, between the iris and the lens. The fact that simple 

 opiitlialmia is accompanied by an inflamed appearance of the eye- 

 lids, which is its first symptom, serves to distinguish it from " worm 

 in the eye," the inflammation of which, unless in very advanced 

 cases, does not extend to the eyelids. The cornea of the filaria- 

 affected eye, generally, assmiies an evenly distributed dimness, 

 which, as a rule, rapidly increases, until the opacity becomes more 

 or less complete. If there be any difficulty in seeing the parasite 

 through the inflamed cornea, the horse should be taken into a 

 dark place, and the eye examined by means of a candle. When 

 the inflammation of the cornea is in its first stage, it may subside 

 to some extent, and the eye may become clearer on account of 

 the parasite ceasing to irritate the parts by inserting itself between 

 the lens and the iris, and remaining there for some time. There 

 will usually be a slight flow of tears from the eye ; which, however, 

 will (unlike an eye suff'ering from simple ophthalmia) evince but 

 little intolerance of light. If we susjoect that the filaria 

 is hiding between the lens and the iris, we may discover its presence 

 in the following manner which has been devised by Mr. Spooner 

 Hart, M.R.'C.V.S. : — ''Place the patient in a darkish stable, and 

 let the light shine into the affected eye from the front and a little 

 to the side of the head, just above the level of the eye, so as to 

 render the interior of the eyeball luminous, and stand about four 

 or five yards off in the line of the light, when a gigantic worm, 

 moving about inside the eye, will be ^dsible." Hart remarks that 

 he has never seen more than one worm in the same eye at the 

 same time. My Indian experience, on this point, is the same as 

 his ; although I have seen a horse in Cambridgeshire, in one of 

 whose eyes I observed several (apparently four or five) filariae 

 moving about. It occasionally happens, even in cases which re- 

 ceive no treatment, that the worm disappears from the eye and 

 leaves no trace behind. The usual ending of untreated cases is 

 that the inflammation caused by the presence of the worm proceeds 



