The relationship between Axial Length and anterior segment biometry in Highly axial Myopic Children and Adolescents Aged 7 to 18 Years

Background: The purpose of this study was to investigate the relationship between axial length(AL) and anterior segment biometry in highly axial myopic children and adolescents. Methods: A cross-sectional study was conducted involving 366,278 students aged 7 to 18. The SUOER Ophthalmic Optical Biometer (SW-9000) was utilized for Ocular Biometric Measurements. A multivariate linear regression model was employed to explore the correlation with AL. Results: Among the participants, 28,877 exhibited highly axial myopia (AL≥26mm), and 995 had super highly axial myopia (AL≥28mm). The average keratometry (K) and lens thickness (LT) of highly axialmyopic students were both smaller than those of the control group (AL<26mm),while corneal astigmatism (CA), central corneal thickness (CCT), and anterior chamber depth (ACD) were greater in the highly axial myopic students. With increasing AL, CA, CCT, and ACD demonstrated an increasing trend, while K showed a decreasing trend. When AL was<27 mm, LT exhibited a trend of thinning with increasing AL, while after AL exceeded 27 mm, LT showed a slow thickening trend with increasing AL. Multivariate linear regression analysis indicated that CA (β=0.206), K (β=-0.273), CCT (β=0.001), ACD (β=1.598), and LT (β=-0.58) were all correlated with AL (all P<0.001). When AL was 0.05). Conclusion: In the children and adolescent, highly axial myopia was associated with lower K, higher CA, thicker CCT, deeper ACD, and thinner LT. When AL is <27 mm, the thinning of the LT may play a role in myopia compensation, but as AL exceeds 27 mm, this crystalline lens compensatory effect gradually diminishes.