Clinical results of LASIK: Comparison by the Different Corneal Flap Diameters

ABSTRACT

PURPOSE: To evaluate clinical results of LASIK according to the different corneal flap diameters. METHODS: LASIK was performed in 31 myopic eyes by using a 8.0 mm stop ring and a 8.25 mm applicator (group 1) or in 31 eyes by using a 8.5 mm stop ring and a 8.75 mm applicator (group 2). We measured the preoperative and postoperative uncorrected visual acuity, corrected visual acuity, corneal flap diameter, refraction, intraocular pressure, corneal thickness and corneal topography. Mean follow-up time of group 1 was 8.09+/-1.92 months and that of group2 was 8.36+/-2.31 months. RESULTS: The mean corneal flap diameter of group 1 was 8.33+/-0.39 mm and that of group 2 was 8.87+/-0.44 mm (P<0.05). The flap thickness of group 2 was also larger (P<0.05). There was no significant difference in the spherical equivalent between the two groups at postoperative 1day and 1week. After 2 months, the mean spherical equivalent of group 1 and group 2 was -0.32+/-0.67 D and -0.01+/-0.65 D respectively (P<0.05). After 6 months, the mean spherical equivalent of group 1 and group 2 was -0.69+/-0.64 D and -0.34+/-0.71 D (P<0.05). There was no significant difference in the mean corneal astigmatic power of 3 mm zone, postoperative intraocular pressure, corneal thickness or uncorrected visual acuity between two groups. CONCLUSIONS: The diameter of corneal flap was measured larger intraoperatively than we had expected. The larger corneal flap group resulted in the postoperative refraction of near emmetropia.