148 OPHTHALMOLOGY FOR VETERINARIANS 



also less danger of complications attending the opera- 

 tion. The section should be made by a pushing or pull- 

 ing movement, with as little sawing motion as possible, 

 as there is less danger of serration of the edges of the 

 wound, and healing takes place more readily. When one 

 considers the anatomic relations, it will be seen that 

 the margin of the cornea must be closely followed. 



Iridectomy is the next step, though this is omitted 

 in simple extraction. With an iridectomy there is less 

 danger of prolapse of the iris through the wound, and 

 the lens is delivered more readily. On the other hand, 

 the pupil is less regular and the vision may not be as 

 perfect, though just as good visual results have been 

 attained following an iridectomy as by the simple ex- 

 traction. 



Iridectomy is performed by passing a special iris for- 

 ceps through the wound, grasping the pupillary border 

 of the iris, withdrawing it through the corneal wound, 

 and snipping off a small portion with a special iris 

 scissors. 



The next step is the cutting of the capsule. Some 

 operators prefer to rupture the capsule by tearing out 

 a portion with a special capsule forceps. A much better 

 method is cutting out a square window by the use of 

 the capsulatome. This instrument is passed in, pushed 

 downward, then horizontally, then upward, then again 

 horizontally to the starting-point. This square section 

 often comes away with the lens, leaving a clear pupil. 



