AIM: To compare the refractive outcomes of femtosecond LASIK with two different flap thickness in the correction of myopia.

METHODS: A total of 236 eyes of 118 myopic patients received LASIK with Wave-Light exeimer laser system. In the non-high myopia group, 30 people(60 eyes)used 90 micron corneal flaps, the other(60 eyes)used 110 micron corneal flaps; in the high myopia group,29 people(58 eyes)used 90 micron corneal flaps,the other(58 eyes)used 110 micron corneal flaps. Uncorrected distance visual acuity(UDVA), corrected distance visual acuity(CDVA), manifest refraction and intraocular pressure before operation, at 1mo, 3mo postoperatively were evaluated.

RESULTS: The percent of postoperative UDVA better than or equal to preoperative CDVA after 3mo: 57 eyes(95%). In the non-high myopia group no matter 90 micron corneal flaps or 110 micron corneal flaps. In the high myopia group, there are 53 eyes(91.4%)with 90 micron corneal flaps and 56 eyes(96.6%)with 110 micron corneal flaps(P=0.438); The percent of spherical equivalent refraction(SE)within ±0.50D of the target refraction change: 51 eyes(85%). In the non-high myopia group no matter 90 micron corneal flaps or 110 micron corneal flaps, 48 eyes(82.8%). In the high myopia group with 90 micron corneal flaps or 110 micron corneal flaps; The percent of change in SE within 0.50D between 1mo and 3mo postoperatively: there are 57 eyes(95%)with 90 micron corneal flaps and 55 eyes(91.7%)with 110 micron corneal flapsin the non-high myopia group(P=0.717). In the high myopia group, there are 44 eyes(75.9%)with 90 micron corneal flaps and 50 eyes(86.2%)with 110 micron corneal(P=0.464).

CONCLUSION: Both 90 micron corneal flaps and 110 micron corneal flaps show similar good efficacy, predictability and stability in the correction of myopia.