Long-Term Refractive Outcome of Small Incision Lenticule Extraction in Very High Myopia

Purpose: To assess the stability, safety, predictability, and efficacy of small incision lenticule extraction (SMILE) in high myopia. Methods: The study was conducted as a retrospective noncomparative analysis of the records of 495 eyes of 270 patients treated by the ReLEx SMILE technique for a mean spherical myopic error of -12.84 ± 2.47 D (range: -10.0 to -14.0 D) combined with a mean astigmatism of -1.17 ± 1.34 D (up to -4.0 D). The mean LogMAR corrected distance visual acuity (CDVA) was 0.2 ± 0.6. In this study, 225 patients had the bilateral SMILE procedure, whereas 45 patients had a single eye treated with SMILE. Results: One month after surgery, the mean refractive error was 20.72 ± 0.88 D (range: +1 to 21.5 D), and the mean postoperative astigmatism was -0.83 ± 1.04 D. The mean LogMAR UDVA was 0.2 ± 0.34. In the last follow-up visit, 3 years after surgery, all the before mentioned parameters were the same or within minimal changes with no statistically significant difference from the earlier results. However, the spherical error demonstrated a significant change from -0.72 ± 0.88 D at 1 month to -1.17 ± 1.01 D at the end of the follow-up. However, this change had an insignificant visual impact. At the end of the follow-up period, approximately 94% of patients had unchanged CDVA or gained one or more lines, 6% lost one line of CDVA, and 1% lost 2 lines. Conclusions: SMILE may be effective and safe, with a stable and predictable outcome for correction of very high myopia.