Abstract / Summary
Myelinated retinal nerve fibers (MRNF) are a rare congenital retinal abnormality associated with high myopia; however, the ocular structural basis of MRNF-related myopic changes remains unclear. This study investigated refractive status and ocular biometric characteristics in children with unilateral MRNF. This retrospective cross-sectional paired-eye study included children with unilateral MRNF. Cycloplegic refraction and ocular biometric parameters were collected. Differences between MRNF and fellow eyes were evaluated, including spherical equivalent (SE), axial length (AL), anterior chamber depth (ACD), lens thickness (LT), central corneal thickness (CCT), keratometric parameters, vitreous chamber depth (VCD), and corneal radius (CR). Correlations between SE and biometric parameters were assessed. 36 children with unilateral MRNF were included, with cycloplegic refraction available for 29 patients. Compared with fellow eyes, MRNF eyes showed greater myopic refractive errors (SE: −8.88 vs. 0.42 D, P < 0.001) and longer AL (25.49 vs. 22.23 mm, P < 0.001). VCD was significantly increased in MRNF eyes (18.10 vs. 15.14 mm, P < 0.001), whereas ACD, LT, CCT, and most corneal parameters showed no significant differences. MRNF eyes had lower LT/AL, ACD/AL, and CCT/AL ratios and higher VCD/AL, AL/CR, and VCD/CR ratios (all P < 0.001). SE was correlated with VCD ( r = − 0.641, P = 0.007) and VCD/CR ( r = − 0.816, P < 0.001). Unilateral MRNF in children is associated with marked refractive asymmetry and predominant posterior ocular elongation, particularly vitreous chamber expansion. These findings suggest altered ocular growth patterns and support biometric assessment and longitudinal refractive surveillance.