The relationship between axial length and anterior segment biometry in high axial myopic Chinese students aged 7 to 18 years

Purpose This study aimed to examine the relationship between axial length (AL) and anterior segment biometry in Chinese children and adolescents with high axial myopia. Methods A cross-sectional study was conducted involving 366,278 Chinese students aged 7 to 18 years from January 2020 to December 2022. The SUOER μ -Meter optical biometric was used for measuring ocular biometric parameters. A multivariate linear regression model was used to examine the correlation with AL. Results Among the participants, 28,877 exhibited high axial myopia (AL ≥ 26 mm). The average keratometry (K) and lens thickness (LT) in the high axial myopia group were significantly lower than those in both the non-myopia and normal myopia groups (all p 0.001). Central corneal thickness (CCT) and anterior chamber depth (ACD) were significantly greater in the high axial myopia group compared to both non-myopia and normal myopia groups (all p 0.001). Multivariate linear regression analysis demonstrated that K ( β = −0.265), CCT ( β = 0.001), ACD ( β = 1.609), and LT ( β = −0.607) were all correlated with AL (all p 0.001). After adjusting for gender and age, when AL was 27 mm, AL was negatively correlated with LT; similarly, when AL exceeded 27 mm, there was no linear correlation between AL and LT ( p 0.05). Conclusion In Chinese children and adolescents, a high AL (i.e., ≥26 mm) was associated with significantly lower K, thicker CCT, and deeper ACD, and thinner LT compared with subjects having AL 26 mm. When AL was 27 mm, LT thinning may contribute to myopia compensation; however, when AL exceeds 27 mm, this compensatory effect of crystalline lens thickness appears to diminish.