The author was presented with 2 monkeys as cataract patients, along with access to fresh cadaver eyes of similar species.

Cataract surgery by phacoemulsification and aspiration was performed on 12 normal fresh cadaver monkey eyes and the difference to similar surgery in canine cadaver eyes was noted. Bilateral cataract surgery was then performed on 2 monkeys.

The main points of comparison were:

 Positioning of patient for surgery

 Stability of eye following corneal incision

 Ease of capsulorhexis

 Ease of phacoemulsification of lens nucleus

 Ease of aspiration of lens cortex

 Ease of capsular polishing

 Return of sight

On each point the author found it the much easier to perform cataract surgery on monkey eyes than on dog eyes. Of particular note was the behaviour of the anterior lens capsule being easier to handle and control while the posterior lens capsule was much tougher and resistant to pressure than their canine counterparts. Mature cataract in an aged patient was much softer and easier to remove than that of a dog of comparative age.

Both monkeys were seen to exhibit normal visual behaviour soon after surgery without any postoperative medication and despite mild occasional self trauma.

The considerable difference in the behaviour of the eyes suggests that a more formal structural comparison should be made of the eyes of these species.