Factors Affecting Visual Outcome After Small Lenticule Extraction Pro® (VISUMAX 800)

This study aimed to report factors affected visual outcome after small incision lenticule extraction (SMILE) in the early experience of treating eyes with VISUMAX 800 (Carl Zeiss Meditec AG). This is a retrospective study with cross-sectional design of eyes underwent SMILE Pro® using VISUMAX 800 in JEC @Kedoya Eye Hospital Jakarta, Indonesia. Patients 40 years old or younger with the corrected distance visual acuity (CDVA) of >20/25, manifest refractive spherical equivalent (SE) ≤10.0 diopters (D), cylinder refraction <5.0 D were included. Evaluation of visual outcome was conducted at 1 day and 1 month postoperatively. All statistical analyses were performed using the SPSS v. 26.0 software (IBM Corp.) based on data normality. A total of 258 eyes from 132 patients were analyzed. 94% of eyes achieve uncorrected distance visual acuity (UDVA) 20/20 1-month post operatively. 81% of high myopic eye achieve UDVA 20/20 following by 97% and 99% in moderate and low myopic eyes, respectively. Spherical equivalent refraction (SER) (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 statistically significant but weak correlation with UDVA 1 month postoperatively. There is increasing risk to get <20/20 UDVA in right eyes (OR 3.101; p<0.045), eyes with high myopia (OR 9.964; p<0.01), 100µm cap thickness (OR 4.578; p<0.01), ≤ 6mm OZ (OR 10.556; p<0.01), and <300µm RST (OR 9.100; p<0.01) 1-month post operatively. SMILE Pro® give promising visual outcome in early post operative period. Low-moderate myopia give better visual outcome than high myopia patient. Small OZ, thin cap thickness, and low RST could increase risk for not getting a maximum visual outcome after SMILE. Study with prospective design and longer follow up time which included comprehensive variables were needed to fully understand factors affecting VA after SMILE.