Comparative analysis of visual outcomes following small‑incision lenticule extraction with or without cyclotorsion compensation in eyes with high astigmatism: Contralateral eye study

Abstract

Purpose: To compare the visual outcomes in patients undergoing small‑incision lenticule extraction (SMILE) for correction of myopic astigmatism (≥−1.50 D) with or without manual cyclotorsion compensation. Methods: A prospective, double‑blinded, randomized, contralateral study was conducted in the refractive services of a tertiary eye care center. Eligible patients with bilateral high myopic astigmatism (≥1.5 D) and intraoperative cyclotorsion (≥5°) undergoing SMILE between June 2018 and May 2019 were included. Cyclotorsion compensation was performed using triple centration method before femtosecond laser delivery. Uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively) measurement, manifest refraction, slit‑lamp biomicroscopy, and corneal tomography were performed preoperatively and at 1 and 3 months’ postoperative visit. Astigmatic outcomes were analyzed using Alpins criteria. Results: A total of 30 patients (60 eyes) were included in this study. The patients underwent bilateral SMILE surgery, with manual cyclotorsion compensation in one eye (CC group, n = 30 eyes) and no cyclotorsion compensation in the other eye (NCC group, n = 30 eyes). Preoperative astigmatism and intraoperative cyclotorsion were −2.0 D and 7.03° ± 1.06° (CC) and −1.75 D and 7.24° ± 0.98° (NCC) (P = 0.472 and 0.240, respectively). No significant differences were noted in mean refractive spherical equivalent (MRSE), UDVA, CDVA, and refractive error between the two groups at 3 months’ postoperative visit. Astigmatic outcomes measured using Alpins criteria demonstrated no significant difference between the two cohorts. Conclusion: The cyclotorsion compensation technique provided no additional advantage in terms of astigmatic outcomes or postoperative visual quality, in eyes with high preoperative astigmatism and intraoperative cyclotorsion.