550 DISEASES OF THE EYES. 



applied as follows: — The eyelid being everted to a greater 

 extent, by traction on tlie neighbouring skin, the caustic is to 

 be pencilled on the conjunctiva in a direction from one angle of 

 the eye to the other, parallel to, but at a httle distance from, the 

 margin of the eyelid. After the application of the caustic the part 

 is to be wiped with a bit of lint, and then pencilled with sweet 

 oil. It is often advantageous to scarify the conjunctiva before 

 applying the caustic. The cauterisation may be repeated in the 

 course of three or four days ; and when it is found insufficient 

 to effect the desired object, it is better to have recourse to the 

 excision of an elliptical-shaped piece of the thickened and 

 sarcomatous conjunctiva parallel to the margin of the eyelid. 



In the case of the horse referred to, the ectropium being 

 large, excision was performed at once ; and in order to effect 

 tliis it became necessary to draw away the lid from the eyeball 

 by traction on the neighbouring sldu ; the diseased conjunctiva 

 was then pinched-up wdtli strong forceps, and the piece cut off 

 with a sharp scalpel. The piece removed must always be of 

 such a breadth as appears sufficient, in order that when the 

 cicatrisation is complete, the contraction of the conjunctiva may 

 neither be so great as to invert the eyelid, nor so little as still 

 to leave some degree of eversion. Further directions for the 

 operation, when it appears necessary to modify the foregoing, 

 may be obtained by referring to Jones' Ophthalmic Medicine. 



ENTROPIUM, OR INVERSION OF THE EYELIDS. 



This is the converse of ectropium ; the free margins of the 

 eyelid and the eyelashes are turned in against the eyeball, 

 wliich they keep in a state of great irritation by the friction 

 they exert upon it. 



The margin of the eyelid may be inverted in part of its 

 extent, constituting partial entropium, but more commonly the 

 entropium is total. One eyelid only may be affected, or both 

 lids of one or both eyes. 



Pointer and setter dogs are very frequently thus affected ; 

 the horse very rarely. The distress occasioned by the friction 

 of the margin of the lid and the eyelashes against the eyeball 

 when an attempt is made to use the eye, must be very great. 

 There is intolerance to light, which forces the animal to keep 



