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

To assess the stability, safety, predictability, and efficacy of small incision lenticule extraction (SMILE) in high myopia.

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.

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.

SMILE may be effective and safe, with a stable and predictable outcome for correction of very high myopia.