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

## TL;DR

This study explores how eye structure changes in Chinese children and adolescents with high myopia, finding specific correlations between eye length and anterior segment measurements.

## Contribution

The study identifies novel correlations between axial length and anterior segment biometry in high axial myopic Chinese students.

## Key findings

- High axial myopia is associated with lower keratometry and lens thickness, and greater central corneal thickness and anterior chamber depth.
- Lens thickness thinning correlates with axial length when AL is below 27 mm, but this correlation disappears when AL exceeds 27 mm.

## Abstract

This study aimed to examine the relationship between axial length (AL) and anterior segment biometry in Chinese children and adolescents with high axial myopia.

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.

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).

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.