Abstract
BACKGROUND: While the role of peripheral retinal defocus in myopia progression has been established, systematic comparisons of defocus patterns across different retinal regions and refractive statuses remain limited. Furthermore, the specific defocus characteristics that can predict axial length (AL) and spherical equivalent (SE) progression warrant further investigation. This study aimed to characterize the regional distribution of peripheral retinal defocus in children and adolescents with varying refractive statuses using multispectral refractive tomography (MRT), and to evaluate its association with SE and AL. METHODS: Retinal defocus values (RDVs) in different eccentricities and quadrants were measured in different refractive groups under cycloplegic conditions using Multispectral Refractive Tomography (MRT). Statistical analysis included group comparisons and correlation analyses between RDVs and SE/AL. Multiple linear regression analyses were performed to analyze the predictors of SE/AL. RESULTS: There were statistically significant differences in RDVs and TRDV in various eccentricities and quadrants among the groups. The RDVs in the low and moderate myopia groups were significantly higher than those in the emmetropia group; RDV20-30 in the moderate myopia group was higher than that in the low myopia group. RDV in the vertical direction showed asymmetry in all three groups, while RDV in the horizontal direction showed asymmetry in the emmetropia and low myopia groups. SE was negatively correlated with age, flat keratometry (Kf), steep keratometry (Ks), TRDV, and RDVs in all eccentricities and quadrants. AL was positively correlated with age, TRDV, and RDVs in all eccentricities and quadrants, while being negatively correlated with Kf and Ks. Age, Kf, Ks, RDV0-10, and RDV10-20 were significant predictors of SE; age, Kf, RDV0-10, RDV10-20, and RDV20-30 were significant predictors of AL. CONCLUSIONS: Retinal defocus in the vertical direction was observed to exhibit asymmetry across all groups, while the horizontal defocus asymmetry appeared to diminish in the moderate myopia group. Furthermore, RDV0-10, RDV10-20, and RDV20-30 were identified as potential significant predictors of AL.