Outcomes of Small Incision Lenticule Extraction: Mild to Moderate Myopia versus High Myopia

Abstract

Purpose: To evaluate the refractive outcomes of small incision lenticule extraction (SMILE) in high myopia patients compared with mild to moderate myopia patients. Methods: This study included 332 eyes of 166 myopic patients treated with SMILE using Visumax 500 kHz femtosecond laser. Treated eyes were divided into 2 groups according to preoperative spherical equivalent (SE): mild to moderate myopia (A group, <-6.0 D) and high myopia (B group, ≥-6.0 D). Follow-up visits were at 1 day, 1 week, 1 month, 3 months, and 6 months. The outcome measures included uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (BDVA), postoperative SE, efficacy index, safety index and predictability. Results: Preoperative SE was -4.85 ± 0.86 D in the A group and -7.70 ± 1.0 D in the B group. No differences were observed between -0.04 ± 0.29 D in the A group and -0.30 ± 0.37 D in the B group at 6 months postoperatively (p = 0.062). At 6 months postoperatively, 98.3% and 97.3% had UDVA of 20/25 or better in the A group and B group, respectively. In the A group, 97.3% and 100% were within ±0.5 D and ±1.0 D of intended correction and in the B group, 91.7% and 96.9% were within ±0.5 D and ±1.0 D, respectively. Efficacy indices were 1.02 ± 0.19 in the A group and 0.99 ± 0.18 in the B group. Safety indices were 1.16 ± 0.16 in the A group and 1.14 ± 0.16 in the B group. The efficacy and safety indices were not significantly different between the A and B groups at 6 months postoperatively (p = 0.09, p = 0.695, respectively). Conclusions: This study showed that SMILE is effective and safe for correcting high myopia as well as mild to moderate myopia. J Korean Ophthalmol Soc 2014;55(7):963-968