VISULYZE: A Novel Nomogram Tool for Optimizing Refractive Outcomes in SMILE Surgery

To evaluate a new nomogram technique, VISULYZE (Carl Zeiss Meditec AG), in small incision lenticule extraction (SMILE) surgery for treatment of myopia and myopic astigmatism.

This was a prospective, nonrandomized, controlled study. VISULYZE is a specialized software platform for refractive surgeons that integrates patient data analysis with personalized nomogram generation. A total of 108 ideal eye examples (spherical equivalent [SE] within ±0.50 diopters [D] at 3 months postoperatively) were used for creation of the nomogram by VISULYZE. Another 100 eyes from 50 patients were enrolled in the SMILE 3.0 group (traditional nomogram), and 107 eyes from 55 patients in the SMILE 4.0 group (nomogram set by VISULYZE). All patients were followed up for 3 months, with monitoring of uncorrected distance visual acuity, corrected distance visual acuity, spherical equivalent, higher order aberrations, and the preoperative and postoperative complications.

A nomogram was derived from a quadratic regression formula generated by VISULYZE to adjust the SE target. The safety of refractive outcome did not differ significantly in the two groups at the 3-month follow-up visit (P > .05). The efficacy index in the SMILE 4.0 group (1.11 ± 0.11) was significantly higher than in the SMILE 3.0 group (1.06 ± 0.14) (P < .05). In the SMILE 4.0 group, the predictability of error was 97% within ±0.50 D and 100% within ±1.00 D, compared with 81% and 99%, respectively, in the SMILE 3.0 group. The error of SE correction was -0.12 ± 0.30 and -0.36 ± 0.27 D for the SMILE 4.0 and SMILE 3.0 groups, respectively. There was no significant difference between the two groups in the root mean square values of total higher order aberrations, coma, trefoil, and spherical aberration at both 1 and 3 months postoperatively (P > .05).

The nomogram generated by VISULYZE demonstrated comparable safety outcomes to a traditional nomogram while achieving significantly superior efficacy. This advanced nomogram technology also improves refractive prediction accuracy for SMILE procedures.