Changes in retinal relative peripheral refraction in low to moderate myopic patients after transepithelial photorefractive keratectomy

Objective: To investigate the changes in retinal relative peripheral refraction and corneal higher-order aberrations (HOAs) in patients with low to moderate myopia following transepithelial photorefractive keratectomy (Trans-PRK), using multispectral refractive topography (MRT). Methods: This retrospective study included 112 eyes from 56 patients who underwent single-step Trans-PRK. Patients were divided into low myopia (LM, -0.50 to -3.00 D) and moderate myopia (MM, > -3.00 D) groups. Retinal defocus values (RDV) across various eccentricities (0-45°) and regions (total, superior, inferior, temporal, nasal) were measured using MRT preoperatively and 3 months postoperatively. Corneal wavefront aberrations were assessed using the Pentacam system. Results: At 3 months postoperatively, significant increases in hyperopic defocus were observed in most peripheral retinal regions (TRDV, RDV-45, RDV-S, RDV-I, RDV-T, RDV-N) compared to baseline in the total cohort (all p < 0.05), except for the central and paracentral areas (RDV-15, RDV-30). A similar trend was found in both the LM and MM groups. Furthermore, corneal HOAs, horizontal coma, vertical coma, and spherical aberration significantly increased after surgery (all p < 0.05). The MM group exhibited significantly higher postoperative HOAs and spherical aberration than the LM group (p < 0.05). Conclusion: Trans-PRK effectively corrects central myopia but induces a significant shift towards relative peripheral hyperopic defocus and increases corneal higher-order aberrations.