Prospective, Contralateral Comparison of 120-μm and 90-μm LASIK Flaps Using the IntraLase FS60 Femtosecond Laser

Abstract

To compare differences in visual acuity, contrast sensitivity, higher order ocular aberrations, quality of life, and patient-reported outcomes at 3 and 6 months postoperatively in eyes with stable myopia undergoing thin-flap (intended flap thicknesses of 120 or 90 μm) LASIK using the VISX Star S4 CustomVue excimer laser (VISX Inc), with flaps created by the IntraLase FS60 femtosecond laser (Abbott Medical Optics). In this prospective study, thin-flap LASIK was performed contralaterally on 94 eyes: 47 eyes with 120-μm intended flap thickness and 47 eyes with 90-μm intended flap thickness. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and higher order aberrations. At 6 months, mean values for UDVA (logMAR) were -0.064±0.077 and -0.051±0.070 in the 120-μm and 90-μm groups, respectively (n=40, P=.431). Visual acuity of 20/20 was achieved in 98% of eyes with 120-μm flaps and 95% of eyes with 90-μm flaps, whereas 20/15 vision was achieved in 50% of eyes with 120-μm flaps and 45% of eyes with 90-μm flaps (P≥.454). Both groups had significant increases in total higher order aberrations (P≤.003). Significant differences were not found between groups in contrast sensitivity (P≥.258), CDVA (P≥.726), total higher order aberrations (P≥.477), or patient-reported outcomes (P≥.132). Patients in both groups reported increased quality of life postoperatively (P≤.002). Under well-controlled surgical conditions, thin-flap LASIK achieved similar results in visual acuity, contrast sensitivity, and low induction of higher order aberrations in eyes with intended flap thicknesses of either 120 or 90 μm.