556 DISEASES OF THE EYES. 



of the parts behind the cornea, and, says the Professor, " Were 

 that once relieved, the cornea would immediately regain its 

 transparency." — (Dick's Manual of Veterinary Science) I think, 

 however, that an impartial investigation of the matter will prove 

 that the opacity is due to the cornea being involved in the 

 inflammation. 



Percivall, describing the opacity of the cornea and anterior 

 chamber, says — " At the beginning, the anterior chamber pre- 

 serves its pellucidity, so that the iris and pupil can be seen, the 

 latter contracted, the former unchanged in colour ; in the course 

 of two or three days, sometimes earlier, the chamber becomes 

 obscured by a dingy- wdiite or amber-coloured deposit floating 

 within it, through which the pupil is hardly discernible, con- 

 tracted, and looking much like the black eye of a garden bean." 

 The opacity of the cornea proceeds from its circumference to its 

 centre, until at last the whole of its surface becomes of a dull 

 greyish hue, and in some cases blood-vessels are seen ramifying 

 over it. Wlien the dulness is great, the iris is invisible, but 

 when it can be seen, it will be found that the pupil is narrow 

 and contracted, the eye altogether presenting evidence of intol- 

 erance to light. In some instances direct evidence of iritis can 

 be distinguished early in the disease, the iris being of a dead 

 amber colour from a deposit of lymph on its surface, as well as 

 upon the corpora nigra. 



Some writers are inclined to give preference to some one 

 particular structure of the eye as the seat of the disease. I am 

 of opinion that it may be considered as jpanophthalmitis, or 

 inflammation of the whole eye, commencing primarily as " oph- 

 thalmia interna posterior." 



The remaining symptoms are turbidity of the aqueous humour ; 

 the corpora nigra lose their jetty blackness ; the pupil becomes 

 more and more contracted ; the conjunctiva intensely reddened ; 

 and in some cases the vessels crowd around the margins of the 

 cornea, across which numbers of them shoot in irregular lines ; 

 occasionally pus forms in the anterior chamber (hyopyon) ; and 

 in rare instances the inflammation may terminate in suppuration 

 of the entire coats, and consequent disruption of their contents, 

 but the common termination is cataract. 



The inflammation is apt to move from one eye to the other, 

 and for this reason, and on account of its recurrent nature, the 

 disease has been described as " gouty ophthalmia." 



