Distribution characteristics of higher-order aberrations and their associations with ocular biometry and myopia in Chinese school-age children.

PURPOSE: To characterize the distributions of ocular and corneal higher-order aberrations (HOAs) in Chinese school-age children and examine their associations with spherical equivalent (SE), ocular biometry, and refractive status. METHODS: This cross-sectional analysis included baseline data from a school-based cohort of Grade 3 students. Ocular and corneal HOAs were measured using the iTrace aberrometer and analyzed over a standardized 5.0-mm diameter. Axial length (AL), mean keratometry (Km), central corneal thickness (CCT), lens thickness (LT), and the axial length-to-corneal radius ratio (AL/CR) were assessed. Noncycloplegic refraction was used to calculate SE. AL/CR was analyzed primarily as a continuous variable, with a secondary categorical comparison using a cutoff of 3.03. Associations were assessed using Spearman rank correlation, and between-group differences using the Mann-Whitney U test. Multiple comparisons were controlled using the Benjamini-Hochberg false discovery rate (FDR) procedure. RESULTS: A total of 1,326 right eyes from 1,326 participants were analyzed. Ocular and corneal Zernike coefficients showed distinct distribution patterns, with primary spherical aberration (Z40) being positive in 97.44% of corneal measurements compared with 59.95% of ocular measurements. After FDR correction, 24 correlations remained statistically significant. Ocular Z40 was negatively correlated with SE and AL and positively correlated with Km, CCT, LT, and AL/CR, with all six associations remaining significant after FDR correction. The correlation magnitudes were modest (absolute ρ ≤ 0.222). The myopia versus non-myopia difference in ocular Z40 was nominally significant (P = 0.031) but did not remain significant after FDR correction (FDR-adjusted P = 0.558); a sensitivity analysis excluding borderline SE values showed the same directional pattern but likewise did not remain significant after correction (FDR-adjusted P = 0.072). In the secondary AL/CR-based categorical analysis, only ocular Z40 remained significant after FDR correction (FDR-adjusted P < 0.001; r = 0.119). CONCLUSIONS: Ocular and corneal HOAs showed distinct distribution patterns in school-age children, and selected HOA components were significantly associated with refractive and ocular biometric characteristics. Ocular Z40 showed significant associations with multiple continuous refractive and biometric parameters after FDR correction. The refractive-status comparison showed a directionally consistent pattern that did not remain significant after correction, whereas the secondary AL/CR-based analysis identified a significant between-group difference in ocular Z40.