Factors Affecting Visual Outcome after Small Incision Lenticule Extraction (SMILE) Pro

Abstract

Purpose: To report the factors affecting visual outcomes after small incision lenticule extraction (SMILE) in eyes treated with the Visumax 800.Methods: This is a retrospective study with cross-sectional design of eyes underwent SMILE Pro using Visumax 800 at Jakarta Eye Center. Patients ≤40 years old with a corrected distance visual acuity of >20 / 25, manifest refractive spherical equivalent ≤10.0 diopters (D), and cylinder refraction <5.0 D were included. Evaluation of visual outcomes was conducted at 1 day and 1 month postoperatively.Results: A total of 258 eyes from 132 patients were analyzed. Among the total, 94% achieved an uncorrected distance visual acuity (UDVA) of 20 / 20 at 1 month postoperatively. Of the eyes with high myopia, 81% achieved a UDVA of 20 / 20, followed by 97% and 99% in moderate and low myopic eyes, respectively. Spherical equivalent refraction (r = 0.273, p < 0.01), optic zone (OZ; r = 0.260, p < 0.01), cap thickness (r = 0.209, p < 0.01), and residual stromal thickness (RST; r = 0.256, p < 0.01) showed a significant but weak correlation with UDVA at 1 month postoperatively. There is increasing risk to get <20 / 20 UDVA in right eyes (odds ratio [OR], 3.101; p < 0.045), eyes with high myopia (OR, 9.964; p < 0.01), 100-μm cap thickness (OR, 4.578; p < 0.01), ≤6 mm OZ (OR, 10.556; p < 0.01), and <300-μm RST (OR, 9.100; p < 0.01) at 1 month postoperatively.Conclusions: SMILE Pro results in promising visual outcome in early postoperative period. Patients with low to moderate myopia have better visual outcomes than those with high myopia. A small OZ, thin cap thickness, and low RST could increase the risk of not achieving the maximum visual outcome after SMILE. A prospective study with a longer follow-up period that includes comprehensive variables is needed to fully understand the factors affecting visual acuity after SMILE.