Postoperative Contrast Sensitivity and Its Association with Lenticule Surface Regularity After KLEx with the VisuMax 800.

PURPOSE: To investigate changes in contrast sensitivity (CS) and their association with Lenticule surface regularity after keratorefractive lenticule extraction (KLEx) performed with the VisuMax 800. PATIENTS AND METHODS: In total, 92 patients (184 eyes) with myopia were recruited between November and December 2024. CS was measured using the quantitative contrast sensitivity function at 1, 3 and 6 months postoperatively. The lenticules were examined using scanning electron microscopy (SEM), and the SEM images were scored using the large language model Doubao-vision-pro 32k. Correlation analysis between Lenticule surface regularity and CS was performed based on the Generalized Estimating Equations model. RESULTS: At 6 months postoperatively, the uncorrected distance visual acuity of all operated eyes was 20/25 or better; none of the eyes lost 1-2 lines of corrected distance visual acuity. Area under the log CS function, cutoff spatial frequency acuity and CS (3.0-18.0 cpd) significantly improved from 1 to 6 months and correlated with visual acuity and refraction (P < 0.05). Lenticule surface regularity, mainly influenced by age (β=0.204, P < 0.001) and cap thickness (β=-0.325, P < 0.001), was significantly associated with CS (3.0 cpd) at 1 and 3 months postoperatively (β=0.027, P=0.005; β=0.028, P=0.006), and with CS (6.0 cpd) at 6 months postoperatively (β=0.035, P=0.001). CONCLUSION: KLEx performed with the VisuMax 800 yields excellent and stable visual outcomes at six months postoperatively and postoperative CS improved over time. Lenticule surface regularity could contribute to postoperative visual quality to a certain extent.