Age- and Myopia-Related Three-Dimensional Remodeling of Choroidal Thickness in Children

Purpose To investigate the three-dimensional (3D) topographic remodeling patterns of choroidal thickness (ChT) in the macular region in children, and their associations with age and myopia related ocular growth. Design Cross-sectional, population-based study. Participants A total of 3508 children (mean age 13.6±3.0 years, range 7-18 years, 47.7% male). Methods Spectral-domain OCT with a 31-horizontal B-scan protocol was performed on right eyes. ChT in each B-scan was automatically segmented and quantified using modified open-source deep learning algorithms (Choroidalyzer). For each eye, a 3D ChT map covering 6×6 mm macular region and composed of 12×12 grids centered on fovea was generated, and both mean thickness and grid-specific thickness values were calculated. Main outcome Measures ChT of each grid, cluster, and macular region; correlation with age, axial length (AL), and sex. Results The mean ChT was 271.8±56.1 μm, with significant variations across non-myopia, low, moderate, and high myopia groups ( P <0.001). Age-related ChT changes showed a distinct temporal-nasal asymmetry pattern, with the nasal region showing the strongest negative correlation with age (r=-0.12), the central region demonstrating a weak correlation (r=-0.07, both P <0.001), while the temporal region remained relatively stable (r=-0.02, P =0.255), resulting in 4.3- and 2.6-fold (95% CI: -0.4-8.9; -0.4-5.7) greater thinning in the nasal and central choroid than in the temporal region, respectively. AL-related ChT changes showed a concentric thinning pattern, characterized by more pronounced foveal thinning (r=-0.51, B=-35.2 μm/mm, both P <0.001) compared with parafoveal (r=-0.48, B=-28.7 μm/mm, both P <0.001) and perifoveal changes (r=-0.42, B=-22.3 μm/mm, both P <0.001), corresponding to 1.6- and 1.3-fold (95% CI: 1.4-1.7; 1.2-1.4) greater thinning in the fovea and parafovea than in the perifovea. Conclusions Using 3D topographic mapping, we provide population-based data on ChT in children, and identified two major spatial remodeling patterns: temporal–nasal asymmetry with age and concentric thinning with increasing axial length. These spatially and temporally distinct remodeling patterns likely reflect both physiological growth and myopia-related structural change, supporting the potential role of ChT as a biomarker for myopia development and progression.