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.

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.

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