We assessed changes of the choroidal thickness in healthy Korean children using enhanced depth imaging (EDI) optical coherence tomography (OCT) and evaluated the association of choroidal thickness and axial length.

Seventy-nine eyes (79 children) within ±1 diopter spherical equivalent underwent horizontal and vertical scan using EDI OCT. Two observers determined independently the choroidal thickness at 1 mm intervals from 3 mm nasal and 4 mm temporal to the fovea and 1 mm superior and inferior to the fovea using the manual caliper provided by the device software. Statistical analysis was performed to evaluate variations of choroidal thickness at each location and to correlate choroidal thickness and axial length. Intraclass correlation coefficient (ICC) was calculated.

The subjects' mean age was 7.67 years. The mean axial length was 22.96 mm and mean subfoveal choroidal thickness was 296.13 μm. The thinnest choroidal thickness was 160.57 μm at 3 mm nasal to the fovea and the thickest was 319.49 μm at 4 mm temporal to the fovea. The choroidal thickness at 1 mm superior (294.70 µm) and inferior (287.11 µm) to the fovea showed no statistical significance compared with the subfoveal choroidal thickness. The mean choroidal thickness was thicker at 3 mm and 2 mm nasal to the fovea in eyes with shorter than the mean axial length ( p < 0.05). For the assessment of intra-observer reproducibility, the ICC ranged from 0.995 to 0.998 ( p < 0.001).

The choroidal thickness increased from the nasal to the temporal direction at the posterior pole and eyes with shorter axial lengths tended to present thicker choroids at the nasal area in healthy Korean children.