Vector analysis of astigmatic correction after single-step transepithelial photorefractive keratectomy and femtosecond-assisted laser in-situ keratomileusis for low to moderate myopic astigmatism

ABSTRACT

Purpose: This study aimed to evaluate the outcomes of astigmatic correction by single?step transepithelial photorefractive keratectomy (TransPRK) and femtosecond?assisted laser in?situ keratomileusis (Femto?LASIK) surgeries. Methods: A total of 218 subjects received TransPRK or Femto?LASIK surgery for the treatment of myopia and astigmatism (?2.25 to ?0.25 D). Refraction errors and uncorrected (UDVA) and corrected distance visual acuity (CDVA) were examined before and at 3 months after surgery. Astigmatism changes were assessed by vector analysis. Results: Preoperative parameters of the TransPRK group were similar to the Femto?LASIK group. UDVA and CDVA at 3 months were similar between both groups. Manifest refraction (MR) spherical equivalent in the TransPRK group (0 ± 0.20 D) was slightly lower compared with the Femto?LASIK group at 3 months (0.11 ± 0.25 D, P = 0.001). MR cylinder was ?0.06 ± 0.19 D in the TransPRK group and ?0.02 ± 0.15 D in the Femto?LASIK group at 3 months (P = 0.135). The index of success (IS) was 0.15 ± 0.36 in the TransPRK group and 0.06 ± 0.17 in the Femto?LASIK group (P = 0.125). The correction index (CI) was 1.03 ± 0.19 in the TransPRK group and 1.01 ± 0.11 in the Femto?LASIK group (P = 0.815). Conclusion: For low to moderate myopic astigmatism, TransPRK provided a comparable astigmatic treatment effect as Femto?LASIK. Myopic astigmatism was both slightly overcorrected after TransPRK and Femto?LASIK surgeries