Comparison of Excimer Laser and Microkeratome Myopic Keratomileusis in Human Cadaver Eyes

Abstract

There are currently four techniques of keratomileusis in clinical use: cryolathe, planar with mold, excimer laser, and in situ. Comparative studies among the techniques are rare in human cadaver eyes. We studied the newest of these techniques using the argon fluoride (193 nm) excimer laser to perform the excision of stroma as compared to the nonfreeze, planar, lamellar myopic keratomileusis using the Barraquer-Krumeich-Swinger (BKS) technique. Corneas were dehydrated in dextran-containing medium. A 9.00-diopter correction was attempted with each technique using the manufacturers' parameters. There were six eyes in each group. Keratometry was done with the instrument (Bausch & Lomb) mounted vertically. The laser group achieved a mean keratometric flattening of 5.80 +/- 1.00 D; the BKS group achieved a flattening of 3.80 +/- 1.30 D. These results demonstrated the difficulty in obtaining results in eye-bank eyes that match those achieved clinically. The different results of these two techniques underscore the need to use clinical data to adjust laser keratomileusis operating parameters.