Ray-tracing guided versus topography-guided FS-LASIK for myopia: a comparative study of relative peripheral refraction and visual quality

PURPOSE: To compare the distribution of relative peripheral refraction (RPR) and higher-order aberrations (HOAs) following ray-tracing-guided (RG) and topography-guided (TG) femtosecond laser-assisted in situ keratomileusis (FS-LASIK), and to investigate their associations with postoperative visual symptoms. METHODS: This study compared the clinical outcomes of RG FS-LASIK and TG FS-LASIK, with 50 eyes from 50 patients prospectively enrolled in each group. Evaluations preoperatively and 3 months postoperatively included visual acuity, manifest refraction, HOAs, RPR, and the quality of vision questionnaire. RPR was assessed via wide-field peripheral refraction and analyzed across eccentricities (5°, 12.5°, 25°, and >25°) within the superior, inferior, nasal, and temporal quadrants. RESULTS: The RG and TG groups showed comparable visual outcomes, with no significant differences in efficacy index (1.16 ± 0.22 vs. 1.14 ± 0.21, p = 0.755) and safety index (1.21 ± 0.22 vs. 1.24 ± 0.21, p = 0.816). Both platforms induced changes in HOAs and coma, whereas reduced spherical aberration was found in the RG group. Both procedures led to a reduction in RPR, a trend that became increasingly prominent in the peripheral region. However, the TG group showed relatively uniform RPR changes across the visual field, whereas the RG group exhibited a significant increase in superior-inferior RPR asymmetry after FS-LASIK. RPR was regionally associated with HOAs, with >25° RPR mainly correlated with spherical aberration (r = -0.458, p < 0.001) and HOAs (r = -0.265, p = 0.008), and superior-inferior asymmetry was negatively correlated with spherical aberration (r = -0.357, p = 0.001). Regression analysis indicated that superior RPR (coef = -0.601, p = 0.001) and superior-inferior (S - I) symmetry (coef = 0.652, p = 0.004) were significantly associated with glare, and a negative shift in spherical aberration (coef = 0.917, p = 0.007) was associated with fewer starburst symptoms. CONCLUSION: Both RG and TG FS-LASIK provide comparable central visual correction, but they exert distinct effects on RPR profiles and HOAs. Postoperative glare was associated with RPR asymmetry, whereas the negative spherical aberration appeared to alleviate starburst symptoms. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2500106477), retrospectively registered on July 24, 2025.