Cut edges and surface characteristics produced by different microkeratomes.

PURPOSE To determine the cutting characteristics of seven different microkeratomes and to compare the cut edges and surface characteristics of the corneas with respect to different keratome parameters, ie, blade oscillation frequencies and keratome speed. METHODS Lamellar keratectomies were performed using each microkeratome on eight freshly enucleated porcine corneas. The freshly cut corneal bed was then examined using scanning electron microscopy. A scoring system was used to evaluate the serration of the cut edge and the regularity of the corneal wound bed. RESULTS Serrated cut edges were produced by the Microtech microkeratome, the Automatic Corneal Shaper, the Draeger rotor keratome, and the Schwind microkeratome. The other tested cutting devices generally yielded a smooth cut edge. Smooth and regular wound surfaces were obtained with the Schwind microkeratome, the Automatic Corneal Shaper, the Microtech microkeratome, and the MKM set. The specimens cut with the Schwind microkeratome showed particularly regular surface characteristics. CONCLUSION The relationship between keratome propulsion speed, blade oscillation frequency, and blade material appears crucial for the quality of the microkeratome cut. Our results favor a low advancement/oscillation ratio among automated microkeratomes.