Comparison of the IntraLase femtosecond laser and mechanical keratomes for laser in situ keratomileusis

Abstract

Purpose: To compare laser in situ keratomileusis (LASIK) results obtained with the femtosecond laser (IntraLase Corp.) to those obtained using 2 popular mechanical microkeratomes. Setting: Private practice, Greensboro, North Carolina, USA. Methods: This retrospective analysis compared LASIK outcomes with the femtosecond laser to those with the Carriazo-Barraquer (CB) microkeratome (Moria, Inc.) and the Hansatome ® microkeratome (Bausch & Lomb, Inc.). The 3 groups were matched for enrollment criteria and were operated on under similar conditions by the same surgeon. Results: There were 106 eyes in the IntraLase group, 126 eyes in the CB group, and 143 eyes in the Hansatome group. One day postoperatively, the uncorrected visual acuity (UCVA) results in the 3 groups were similar; at 3 months, the UCVA and the best spectacle-corrected visual acuity results were not significantly different. A manifest spheroequivalent of ±0.50 diopter (D) was achieved in 91% of eyes in the IntraLase group, 73% of eyes in the CB group, and 74% of eyes in the Hansatome group ( P<.01). IntraLase flaps were significantly thinner ( P<.01) and varied less in thickness ( P<.01) than flaps created with the other devices. The mean flap thickness was 114 μm ± 14 (SD) with the IntraLase programmed for a 130 μm depth, 153 ± 26 μm with the CB using a 130 μm plate, and 156 ± 29 μm with the Hansatome using a 180 μm plate. Loose epithelium was encountered in 9.6% of eyes in the CB group and 7.7% of eyes in the Hansatome group but in no eye in the IntraLase group ( P = .001). Surgically induced astigmatism in sphere corrections was significantly less with the IntraLase than with the other devices ( P<.01). Conclusions: The IntraLase demonstrated more predictable flap thickness, better astigmatic neutrality, and decreased epithelial injury than 2 popular mechanical microkeratomes.