Comparison of Initial Visual Outcomes Following Keratorefractive Lenticule Extraction (KLEx) Using VisuMax 500 Versus VisuMax 800.

Purpose This study aims to compare the initial three-month outcomes of a single-center experience with small incision lenticule extraction (SMILE) for correction of myopia and myopic astigmatism using the VisuMax 500 (Carl Zeiss Meditec, Jena, Germany) versus the VisuMax 800 (SMILE Pro®; Carl Zeiss Meditec, Jena, Germany). This experience is compared to the US Food and Drug Administration approval studies and published literature. Patients and methods The initial 45 eyes (23 patients) that underwent SMILE with the VisuMax 500 in 2018 were compared with the initial 42 eyes (21 patients) that underwent SMILE Pro® with the VisuMax 800 in 2024. These patients represent the first to be treated with SMILE or SMILE Pro® at a single institution in Draper, Utah. Data from postoperative visits up to three months of follow-up were collected and analyzed. Generalized estimating equations (GEE) were used in our analysis to account for inter-eye bias. Results By three months, six eyes (13.3%) reported uncorrected distance visual acuity (UDVA) of 20/16 or better in the VisuMax 500 group compared to nine eyes (23.1%) in the VisuMax 800 group. All 87 eyes had a UDVA of 20/40 or better at three months. There was no statistically significant difference in the mean postoperative UDVA (logMAR) between platforms (0.02 ± 0.07 vs 0.04 ± 0.15; P = 0.315). Safety and efficacy indices were also comparable between platforms (P = 0.406 and 0.239, respectively). VisuMax 800 demonstrated less undercorrection of astigmatism compared to VisuMax 500; however, this was not statistically significant (P = 0.174). Conclusion Both platforms remain safe and effective for the treatment of myopia with and without astigmatism. Despite the improved ergonomic technology of the VisuMax 800, its three-month visual outcomes are comparable to those of the VisuMax 500.