98 OPHTHALMOLOGY FOR VETERINARIANS 



The characteristic radiation of the blood-vessels, its 

 location, together with the presence of trachoma, serve 

 to distinguish it from other diseases of the cornea. 



When the Hds are contracted and the palpebral 

 fissure is lessened in consequence, the greater is the 

 liabiHty of its occurrence. The superficial type readily 

 clears up under proper treatment, but the longer the 

 disease prevails and the deeper the structures involved, 

 the more certain will there be a permanent opacity. 



Treatment. — The main indications are to relieve the 

 pressure of the Hds upon the cornea, and to treat the 

 trachomatous disease of the conjunctiva as described 

 under that head. The pressure can be relieved by 

 dividing the outer tendon of the orbicularis muscle as 

 follows: Pass the blunt end of the blade of a strong 

 pair of scissors horizontally beneath the outer canthus, 

 the other above, make one quick snip; at the same time 

 keep the parts stretched with the thumb and forefinger 

 of the other hand. If the result is unsatisfactory, 

 divide the remaining strands with a small pair of scissors. 

 Bleeding can easily be stopped by compression, and the 

 wound heals rapidly. This operation is known as 

 canthotomy. 



If one desires to draw the wound together to obtain 

 a permanent result, three sutures may be introduced 

 horizontally, one through the conjunctiva to the ex- 

 treme angle of the wound, the remaining two, one 

 above and one below, at a point midway between the 



