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

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

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.

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.

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