Clinical Outcomes After SMILE and Femtosecond Laser-Assisted LASIK for Myopia and Myopic Astigmatism: A Prospective Randomized Comparative Study

Purpose:To compare the clinical outcomes of small-incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK (FS-LASIK) for the correction of myopia and myopic astigmatism.Methods:In this prospective, randomized, comparative study, SMILE surgery was performed in 113 eyes with a mean spherical equivalent (MSE) of -5.22 1.70 diopters (D) and FS-LASIK was performed in 84 eyes with an MSE of -5.18 1.93 D. Contrast sensitivity and uncorrected and corrected distance visual acuities were measured preoperatively and 1 day, 1 week, 1, 3, and 6 months postoperatively. Higher-order aberrations were evaluated preoperatively and 6 months postoperatively.Results:At postoperative day 1, the uncorrected distance visual acuity in the FS-LASIK group was better (P < 0.05), whereas no statistically significant difference was found at 6 months postoperatively (P = 0.9). There was no significant difference in terms of logMAR corrected distance visual acuity and MSE during the 6 months of follow-up between the SMILE and FS-LASIK groups (all P > 0.05). The contrast sensitivity in the SMILE group was lower at 1 day and 1 week postoperatively (all P < 0.05). The spherical aberration at 6 mm diameter at 6 months postoperatively was lower (P < 0.05) in the SMILE group (0.12 +/- 0.22 m) than in the FS-LASIK group (0.28 +/- 0.26 m).Conclusions:Both FS-LASIK and SMILE procedures achieved good visual outcomes in the correction of myopia and myopic astigmatism. SMILE had a lower induction rate of spherical aberration at 6 months postoperatively in the analysis of 6 mm diameter than that of FS-LASIK.