A study on the correlation between ocular biometric parameters and myopia in children and adolescents: a large-scale population-based study in Chengdu, China

Abstract PURPOSE:To investigate the characteristics and correlation of myopia and ocular biometric parameters among students in Chengdu. DESIGN:This cross-sectional analysis of the Chengdu included students between the ages of 3 and 18 years (n = 509 530). METHODS:Myopia, defined as spherical equivalent (SE) ≤ -0.50 D and UCVA > 0.3 logMAR for participants aged 3 years, SE ≤ -0.50 D and UCVA > 0.2 logMAR for those aged 4-5 years, SE ≤ -0.50 D and UCVA > 0 logMAR for those aged ≥6 years. All participants received non-cycloplegic autorefraction,uncorrected visual acuity (UCVA) and ocular biometric parameters. Pearson correlation analysis and multiple linear regression model were used to analyze the relationship between ocular biometric parameters and myopia. RESULTS: The overall prevalence of myopia was 40.9% (95% CI: 40.77- 41.04% ). SE had strong correlations with axial length(AL), AL/CR ratio, and vitreous chamber depth, moderate correlations with lens thickness(LT) and anterior chamber depth, and weak correlations with keratometry and central corneal thicknesss ( P< 0.001). The slopes of changes in AL and LT were highly consistent between myopic and non-myopic children aged 3-6 years. However, between 6-9 years of age, myopic children exhibited faster AL increase and greater LT thinning than non-myopic children (P < 0.001) with age. After 9 years of age, changes in both AL and LT gradually stabilized. CONCLUSIONS:In children aged 6-9 years, a rapid increase of AL has occurred and accompanied by compensation from LT to maintain emmetropization, which gradually diminishes after age 9, suggesting that AL and LT are essential indicators for myopia control in children.