Regularity of Human Corneal Flaps Prepared by Femtosecond Laser Technology

Purpose To evaluate the regularity of intracorneal femtosecond laser incisions for preparation of corneal flaps for LASIK. Methods Using a corneal contact lens and a femtosecond laser, superficial corneal flaps of two different thicknesses (140 µm and 260 µm) were created in five human donor eyes. The uniform evenness of the corneal flap thickness was assessed histomorphometrically. Results The coefficient of variation was 0.12 for the thin flaps and 0.77 for the thick flaps. Flap thickness did not vary statistically significantly between the peripheral half of the flap diameter (189.9±71.1 µm) and the center of the flap (198.8±80.2 µm). Mean thickness was 133.7±15.33 µm (median 141.1 µm; range: 105 to 151 µm) for the 140-µm intended flaps, and 268.53±20.6 µm (median 269.0 µm; range: 231 to 295 µm) for the 260-µm intended flaps. Conclusions Femtosecond laser–prepared corneal LASIK flaps may have acceptable regularity for clinical purposes. [ J Refract Surg . 2008;24:645–648.]