Correction of Astigmatism With SMILE With Axis Alignment: 6-Month Results From 622 Eyes

Abstract

Purpose: To evaluate postoperative clinical outcomes in myopic eyes with astigmatism that underwent femtosecond laser small incision lenticule extraction (SMILE) surgery with axis alignment.

Methods: Overall, 622 eyes from 353 patients with myopia and astigmatism greater than -0.75 diopters (D) who had SMILE were included in this prospective study. Standard examinations were performed and visual acuity and vector astigmatism values were analyzed preoperatively and postoperatively.

Results: Preoperative manifest spherical equivalent (SE) was -6.11 ± 1.68 D (range: -0.50 to -11.25 D) and manifest refractive cylinder was -1.60 ± 0.65 D (range: -0.75 to -6.25 D). In 622 enrolled eyes with astigmatism, 29.9% did not require rotation modification during surgery, and the average rotation degree (absolute) was 2.82° ± 1.44° (range: 0° to 10°). By 6 months after SMILE, all eyes showed improved uncorrected distance visual acuity (UDVA); approximately 96.8% of eyes with astigmatism achieved the same or better UDVA postoperatively compared to the preoperative corrected distance visual acuity (CDVA). Moreover, the cylinder of all eyes was within ±1.00 D, and 97% of eyes were within ±0.50 D. Only 47 eyes exhibited a low degree of astigmatism (range: -0.75 to 0.50 D). In patients with high astigmatism (>-3.00 D), the preoperative CDVA was -0.02 ± 0.11 logMAR and the 6-month postoperative UDVA was -0.01 ± 0.16 logMAR (n = 24, P > .05), further implying the effectiveness of modified SMILE for refractive correction in patients with astigmatism.

Conclusions: SMILE with axis alignment provides efficient, predictable, and safe refractive correction in patients with myopic astigmatism. [J Refract Surg. 2019;35(3):138-145.].