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

TLDR

LASIK flap creation can be performed with femtosecond lasers or mechanical microkeratomes. The study compared LASIK outcomes using the IntraLase femtosecond laser to those obtained with the Carriazo‑Barraquer and Hansatome mechanical microkeratomes. A retrospective analysis matched 106, 126, and 143 eyes in the IntraLase, CB, and Hansatome groups, respectively, and all procedures were performed by the same surgeon under similar conditions. IntraLase flaps were thinner, more uniform, caused less epithelial injury, and produced less surgically induced astigmatism, while visual acuity outcomes and refractive accuracy were comparable across all devices.

Abstract

To compare laser in situ keratomileusis (LASIK) results obtained with the femtosecond laser (IntraLase Corp.) to those obtained using 2 popular mechanical microkeratomes.Private practice, Greensboro, North Carolina, USA.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.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 microm +/- 14 (SD) with the IntraLase programmed for a 130 microm depth, 153 +/- 26 microm with the CB using a 130 microm plate, and 156 +/- 29 microm with the Hansatome using a 180 microm 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).The IntraLase demonstrated more predictable flap thickness, better astigmatic neutrality, and decreased epithelial injury than 2 popular mechanical microkeratomes.