Vector outcomes after SMILE pro with the VISUMAX 800 for high versus moderate-to-low astigmatism: a contralateral eye comparison

Purpose To evaluate vector outcomes and higher-order aberrations (HOAs) in eyes with high astigmatism (HA) and their contralateral eyes with moderate-to-low astigmatism (MLA) after small-incision lenticule extraction (SMILE Pro) with automated cyclotorsion compensation. Methods This single-center retrospective study included 30 patients (60 eyes) who underwent bilateral SMILE Pro using the VISUMAX 800 platform with OcuLign iris registration. The eyes were classified as HA [> 2.00 diopters (D)] or MLA (≤ 2.00 D) according to their preoperative cylinder magnitude. Visual acuity, refractive outcomes, Alpins vector parameters, intraoperative decentration, and HOAs were compared at 6 months after surgery. Results The mean preoperative manifest cylinder was 2.38 ± 0.25 D in HA eyes and 1.41 ± 0.49 D in MLA eyes. At 6 months, uncorrected distance visual acuity was comparable between eye groups ( p = 0.40). The correction index (0.95 ± 0.10 vs. 0.96 ± 0.12; p = 0.52), absolute angle of error (2.42 ± 2.49° vs. 1.99 ± 2.34°; p = 0.46), and index of success were similar between HA and MLA eyes. Residual cylinder and difference vector were nominally higher in HA eyes in the unadjusted analyses, but the paired differences were small (both 0.13 D) and did not remain statistically significant after false discovery rate correction. Horizontal intraoperative decentration and trefoil also showed nominal unadjusted differences that did not remain significant after FDR correction. Postoperative total HOAs, spherical aberration, and coma were comparable between groups. Conclusion In this small retrospective contralateral-eye cohort, SMILE Pro with OcuLign-assisted cyclotorsion compensation showed favorable 6-month visual, refractive, and vector outcomes in eyes with astigmatism slightly above 2.00 D. These findings should be interpreted cautiously given the modest sample size, narrow HA range, and absence of a non-inferiority design.