Association of quantitative retinal microvascular characteristics with mild myopia in school-aged children: a cross-sectional study using RMHAS

Introduction To explore the association of quantitative retinal microvascular characteristics with mild myopia in school-aged children using the Retina-based Microvascular Health Assessment System (RMHAS) platform. Methods In this cross-sectional study, a total of 525 participants (305 boys and 220 girls, mean age 9.83 ± 2.56 years) with spherical equivalent refraction (SER) within ± 3.00 D were included. We quantified retinal vascular parameters (fractal dimension, diameter, density) using RMHAS, and examined their associations with SER. Results The comparison between myopia and non-myopia groups revealed significant differences in multiple arterial microvascular parameters, including central retinal artery equivalent (CRAE), arterial calibre, vessel skeleton density (VSD) and vessel area density (VAD) (all p < 0.05). Compared with the non-myopia group, the myopia group showed significantly lower CRAE, arterial calibre, and VAD in peripheral retina, but higher VSD. In contrast, only a limited number of venous parameters exhibited significant difference, with the exception of venous Bifurcation Coefficient (BC). However, these associations with SER remained significant after multivariable adjustment and Benjamini–Hochberg false discovery rate (FDR) procedure for both arterial calibre ( β = 0.10; P = 0.0072, q = 0.026) and arterial VAD in the peripheral retina ( β = 0.001; P = 0.0085, q = 0.026). Conclusion Our results revealed an association between mild myopia and reduced retinal vascular density and arterial calibre in school-aged children. These cross-sectional findings cannot determine whether microvascular alterations precede myopia onset or are secondary to axial elongation. Longitudinal studies are required to establish temporality. RMHAS serves as an efficient tool for retinal microvascular assessment.