Comparison of Refractive Outcomes in Small-Incision Lenticule Extraction Performed with One or Two Incisions

PURPOSE: To retrospectively compare the refractive outcomes between two groups of small-incision lenticule extraction (SMILE), one with a single incision and the second one with dual-incisions. SETTING: Ebsar Eye Center, Benha, Qalyopia, Egypt. DESIGN: A retrospective cohort study. METHODS: This study was made up of two groups (162 eyes each): all eyes in group 1 had one SMILE cut at 120°, and all eyes in group 2 had double SMILE incisions, the first incision at 120° and the second one at 270°. Refractive outcomes between the two groups were compared at 3, 6, and 12 months after surgery. RESULTS: The mean preoperative refractive spherical equivalent (MRSE) was −5.75 ± 2.59 D and −6.38 ± 2.18 D in group 1 and 2, respectively (P = 0.73), and a cylinder of 1.25 ± 0.83 D and 0.75 ± 0.81 D, respectively (P = 0.85). At 12 months postoperatively, in group 1, 162 eyes (100%) achieved a UCVA of 20/25, 154 eyes (95.06%) achieved a UCVA of 20/20, and 110 eyes (67.90%) achieved 20/16. In group 2, 162 eyes (100%) achieved a UCVA of 20/25, 156 eyes (96.29%) achieved a UCVA of 20/20, and 113 eyes (69.75%) achieved 20/16. The mean MRSE at 12 months postoperatively was −0.25 ± 0.33 D in group 1 and −0.5 ± 0.33 D in group 2 (P = 0.62). CONCLUSION: Dual-incision SMILE is safe and effective as single-incision SMILE, with a predictable and stable effect in correcting myopia and myopic astigmatism.