Visual and refractive outcomes of small incision lenticule extraction for the correction of myopia: 1-year follow-up

Objective: To assess the 1 year clinical outcomes of small incision lenticule extraction (SMILE) for the correction of myopia and myopic astigmatism using a 500 kHz femtosecond laser system. Methods: This prospective study evaluated 52 eyes of 39 consecutive patients (31.8 +/- 6.9 years, mean age +/- SD) with spherical equivalents of -4.11 +/- 1.73 D (range, -1.25 to -8.25 D) who underwent SMILE for myopia and myopic astigmatism. Preoperatively, 1 week, and 1, 3, 6 and 12 months postoperatively, we assessed the safety, efficacy, predictability, stability, corneal endothelial cell loss and the adverse events of the surgery. Results: The logarithm of the minimal angle of resolution (logMAR) uncorrected distance visual acuity and LogMAR corrected distance visual acuity were -0.16 +/- 0.11 and -0.22 +/- 0.07, respectively, 1 year postoperatively. At 1 year, all eyes were within +/- 0.5 D of the targeted correction. Manifest refraction changes of -0.05 +/- 0.32 D occurred from 1 week to 1 year postoperatively (p = 0.20, Wilcoxon signed-rank test). The endothelial cell density was not significantly changed from 2804 +/- 267 cells/mm(2) preoperatively to 2743 +/- 308 cells/mm(2) 1 year postoperatively (p = 0.12). No vision-threatening complications occurred during the observation period. Conclusions: SMILE performed well in the correction of myopia and myopic astigmatism, and no significant change in endothelial cell density or any other serious complications occurred throughout the 1-year followup period, suggesting its viability as a surgical option for the treatment of such eyes.