Choroidal Thickness in Childhood

Abstract
Purpose. We examined choroidal thickness (ChT) and its spatial distribution across the posterior pole in pediatric subjects with normal ocular health and minimal refractive error. Methods. ChT was assessed using spectral domain optical coherence tomography (OCT) in 194 children aged 4 to 12 years, with spherical equivalent refractive errors between +1.25 and −0.50 diopters sphere (DS). A series of OCT scans were collected, imaging the choroid along 4 radial scan lines centered on the fovea (each separated by 45°). Frame averaging was used to reduce noise and enhance chorioscleral junction visibility. The transverse scale of each scan was corrected to account for magnification effects associated with axial length. Two independent masked observers segmented the OCT images manually to determine ChT at foveal center, and averaged across a series of perifoveal zones over the central 5 mm. Results. The average subfoveal ChT was 330 ± 65 μm (range, 189–538 μm), and was influenced significantly by age (P = 0.04). The ChT of the 4- to 6-year-old age group (312 ± 62 μm) was significantly thinner compared to the 7- to 9-year-olds (337 ± 65 μm, P < 0.05) and bordered on significance compared to the 10- to 12-year-olds (341 ± 61 μm, P = 0.08). ChT also exhibited significant variation across the posterior pole, being thicker in more central regions. The choroid was thinner nasally and inferiorly compared to temporally and superiorly. Multiple regression analysis revealed age, axial length, and anterior chamber depth were associated significantly with subfoveal ChT (P < 0.001). Conclusions. ChT increases significantly from early childhood to adolescence. This appears to be a normal feature of childhood eye growth.