Relationship between acceleration of axial elongation and ocular biometry in schoolchildren.

Purpose: The speed of axial elongation typically slows during the growth phase; however, in some eyes, it accelerates, leading to myopia progression during school age. This study examined the association between ocular biometrics and the acceleration of axial elongation (AAE) in children.

Study design: Longitudinal, prospective, observational study METHODS: This cohort study included 67 right eyes of elementary school children, tracked over six years (from ages 8.5 to 14.5). Annual measurements were conducted for optical axial length, anterior chamber depth, and lens thickness. Yearly axial elongation was calculated for each time period, and AAE was estimated using regression analysis coefficients. Spearman's correlation was used to evaluate the association between AAE and ocular biometric parameters measured in the first year.

Results: The average axial length in the initial year was 23.37 ± 0.89 mm. By the sixth year, the mean axial elongation reached 1.50 ± 0.49 mm, while the average AAE was recorded as -0.015 ± 0.048. AAE was significantly correlated with first-year axial length (r = - 0.40, p < 0.001), anterior chamber depth (r = 0.33, p = 0.007), and lens thickness (r = - 0.42, p < 0.001).

Conclusion: Some eyes with hyperopic ocular biometry at 8.5 years of age exhibited accelerated axial elongation during school age. Future research on myopia should consider both acceleration and axial elongation.