Visual and refractive outcomes of small-incision lenticule extraction in mild, moderate, and high myopia: Six-month results

Abstract

PURPOSE: To evaluate the efficacy, safety, predictability, and stability of small-incision lenticule extraction in low, moderate, and high myopia. DESIGN: Prospective case series. METHODS: Eyes were divided into a low myopia group (spherical equivalent [SE] refraction -1.00 to -3.00 diopters [D]), moderate myopia group (SE refraction of -3.25 to -6.00 D), and high myopia group (SE refraction -6.25 to -10.00 D). Small-incision lenticule extraction surgery was performed, and outcomes were reported 6 months postoperatively. RESULTS: The low myopia group comprised 94 eyes; the moderate myopia group, 95 eyes; and the high myopia group, 85 eyes. There was significant improvement in uncorrected (UDVA) and corrected (CDVA) distance visual acuities, sphere, cylinder, and SE in all groups 6 months postoperatively. The difference in postoperative UDVA, sphere, and SE was statistically significant between the low and moderate myopia groups and the high myopia group; however, there was no difference in the CDVA, cylinder, efficacy, or safety indices. The difference between the attempted SE and achieved SE correction was 0.12 D ± 0.14 (SD) in the low myopia group, -0.18 ± 0.02 D in the moderate myopia group, and -0.60 ± 0.03 D in the high myopia group. There was no statistically significant change in the postoperative SE in any group at 3 months or 6 months. CONCLUSIONS: Small-incision lenticule extraction showed acceptable efficacy, safety, predictability, and stability in low, moderate, and high myopia. The tendency toward undercorrection in the high myopia group suggests the need to modify the nomograms of small-incision lenticule extraction in highly myopic patients.