Comparison of early clinical and optical quality-related outcomes after SMILE using VisuMax 800 versus VisuMax 500...

To compare early clinical outcomes, centration accuracy, and optical quality-related parameters after small incision lenticule extraction (SMILE) performed using the VisuMax 800 and VisuMax 500 platforms in a Chinese population with myopia and low-to-moderate astigmatism.

This retrospective, single-center comparative study included 200 patients (200 eyes) who underwent SMILE between May and August 2025. Patients were grouped according to the laser platform used in routine clinical practice: the SMILE group (VisuMax 500, n = 100) and the SMILE Pro group (VisuMax 800, n = 100). To avoid inter-eye correlation, one eye per patient was included in the analysis. Baseline characteristics were comparable between groups. At 3 months postoperatively, outcomes assessed included visual acuity, refractive outcomes, optical zone decentration, corneal higher-order aberrations, astigmatism vector parameters using the Alpins method, and exploratory correlation analyses between centration metrics and postoperative optical and astigmatic outcomes.

No significant between-group differences were observed in postoperative uncorrected or corrected distance visual acuity, safety index, or efficacy index (all p > 0.05). Compared with the SMILE group, the SMILE Pro group showed significantly shorter lenticule creation time (9.47 ± 0.88 s vs. 27.43 ± 2.26 s, p < 0.01), lower absolute Y-axis decentration and total optical zone decentration (both p < 0.01), and lower postoperative vertical coma (p = 0.004). Postoperative residual cylindrical error was also lower in the SMILE Pro group (p = 0.048), although the absolute between-group difference was small. In astigmatism vector analysis, the SMILE Pro group showed lower magnitude of error and index of success values (both p < 0.05). Exploratory correlation analysis showed a significant positive association between vertical decentration and postoperative vertical coma in both groups, whereas total decentration was significantly associated with the index of success only in the SMILE group.

At 3 months postoperatively, both VisuMax 500-and VisuMax 800-based SMILE showed favorable safety and efficacy for the correction of myopia and low-to-moderate astigmatism. Compared with conventional SMILE (VisuMax 500), SMILE Pro (VisuMax 800) was associated with shorter laser scanning time, lower optical zone decentration, lower postoperative vertical coma, and more favorable astigmatic vector outcomes. These findings represent early postoperative results and should be interpreted cautiously. Further prospective, multicenter studies with larger sample sizes and longer follow-up are warranted.