Surgically induced astigmatism in human cadaver eyes.

A human cadaver eye model was used to study the effects of various sized limbal and scleral-pocket-type incisions on corneal astigmatism. Limbal incisions of 5.0 mm and 10.0 mm and scleral pocket incisions of 3.5 mm and 7.0 mm were carefully placed in human cadaver eyes. These wounds were closed in a uniform fashion, first loosely and then tightly, using interrupted 10-0 nylon sutures. Pre-incision and post-incision keratometer readings were taken and the net change in astigmatic error was calculated. The results indicate that tighter sutures, larger wound size, and limbal rather than scleral-pocket-type incisions were associated with a greater degree of immediate postoperative astigmatism in the cadaver eye.