AIM: To investigate the dynamic response of cornea after the femtosecond laser-assisted laser in situ keratomileusis(LASIK)and to evaluate the risk factors for interface haze formation after thin-flap femtosecond laser-assisted LASIK.

METHODS: One hundred and ninety-eight eyes of ninety-nine subjects with age from 19 to 23 years old, spherical equivalent refraction of -2.75- -12.50D and the central corneal thickness was 492 - 558 μm underwent the femtosecond laser LASIK with Femto LDV femtosecond laser-assisted LASIK for myopic correction, were analyzed from November 1, 2011 to March 31, 2012. The surgical parameters were set as follows: laser frequency 1MHz,flap diameter 8.5-9.0 mm and expected flap thickness 110μm, Japan TOMEY SP100 ultrasonic corneal thickness gauge, used for predetermining 110μm thickness for femtosecond flap, the actual measure thickness was 95-103μm, with an average of 98.00μm. And light scattering were assessed in all eyes that developed haze postoperatively.

RESULTS: Haze was observed in 19 eyes treated, the time of finding the haze was: 2 weeks in 2 cases of 4 eyes, 1 month 8 cases of 15 eyes. There were 14 eyes of grade 0.5. 5 eyes were grade 1. The haze usually occurred in the center of the optical zone, of which the diameter was about 3.0 - 4.5mm, and a small portion of it occurred in the nasal.

CONCLUSION: Interface haze is associated with an ultra thin femtosecond laser flap setting of 95-103μm and younger age among eyes following LASIK for myopia.