Comparison of Small Incision Lenticule Extraction and Transepithelial Photorefractive Keratectomy in Terms of Visual Quality and Accommodation in Myopic Patients

To investigate the differences of surgical results, visual quality and accommodative function between small incision lenticule extraction (SMILE) and transepithelial photorefractive keratectomy (tPRK). Prospective study analyzing 279 eyes of 143 myopic patients. Included 71 patients 140 eyes undergoing SMILE and 72 patients 139 eyes undergoing tPRK. Measures included visual acuity, refractive error, total and corneal higher order aberrations (HOAS), and accommodative function at baseline and 1 and 3 months postoperatively. At 3 months postoperatively, both SMILE and tPRK demonstrated comparable safety and efficacy profiles. The safety index (SI) was 1.19 ± 0.18 for SMILE versus 1.15 ± 0.15 for tPRK (P = 0.12), while the efficacy index (EI) showed 1.24 ± 0.19 for SMILE versus 1.22 ± 0.18 for tPRK (P = 0.12). Notably, SMILE induced greater vertical coma aberrations and trefoil aberrations compared to tPRK, regardless of pupil diameter. Despite this, total higher-order aberrations (HOAs) decreased in the SMILE group but increased in the tPRK group, though the inter-group difference was not statistically significant (P = 0.16). Regarding accommodative function, both procedures improved postoperative parameters. At 1 month, SMILE demonstrated superior performance in relative accommodation (PRA) and monocular accommodative amplitude (MMA) compared to tPRK (P < 0.05 for both). No statistically significant differences were observed in other parameters between the groups at any follow-up time point. Both SMILE and tPRK are effective and safe for correcting mild to high myopia. SMILE induces more corneal aberrations but shows earlier enhancement of accommodative reserve compared to tPRK.