Confocal Microscopy Comparison of IntraLase Femtosecond Laser and Moria M2 Microkeratome in LASIK

Abstract

To analyze the quality of LASIK flaps created using a femtosecond laser or a mechanical microkeratome. A prospective study of consecutive bilateral LASIK flaps (100 patients) created with a 15 kHz femtosecond laser (IntraLase) or with a mechanical microkeratome (Moria M2) was performed. Outcome measures included visual and refractive outcomes, flap dimensions, and intraoperative complications. The first consecutive ten patients (20 eyes) were examined using confocal microscopy 1 and 3 months following surgery. No significant differences were noted in the visual outcomes between groups (t test, P > .05 for all comparisons). Analysis of superficial measurements revealed more round flaps and greater predictability in surface dimensions for the femtosecond laser group (t test, P = .016). Mean deviation of flap thickness from target was the same for both instruments, 10 microm, with greater variability for the mechanical microkeratome. The incidence of diffuse lamellar keratitis was significantly greater in the femtosecond laser group (17%) than in the mechanical group (0%) (chi-square test, P < .001). Confocal microscopy revealed a higher wound healing opacity index in the femtosecond laser group. Although the clinical results are similar, the femtosecond laser produces LASIK flaps with more accurate dimensions compared to the mechanical microkeratome.