PURPOSE: To examine choroidal thickness in a population-based child cohort in relation to birth parameters.

METHODS: The Copenhagen Child Cohort 2000 Eye Study examined 1406 children aged 11 to 12 years using enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT), ocular biometry and measurement of height, weight, refraction, and self-reported pubertal development status. Birth parameters were obtained from the Danish Medical Birth Registry.

RESULTS: The subfoveal choroid in low birth weight children (<2500 g, n = 51, mean 324 ± 76 μm) was thinner than in normal birth weight children (2500-4500 g, n = 1194, mean 361 ± 78 μm), the difference being -37 (CI95 -60 to -15) μm, P = 0.001 after adjusting for age, sex, height, Tanner stage by sex, axial length, anterior chamber depth, and spherical equivalent refractive error. The subfoveal choroid in high birth weight children (>4500 g, n = 48, mean 351 ± 63 μm) was comparable with normal birth weight children, P = 0.44. The subfoveal choroid was thinner in preterm children, however the difference was not significant (-18 [-37 to 2] μm, P = 0.08). Small for gestation children had thinner subfoveal choroid (-19 [-37 to -1] μm, P = 0.04) compared with appropriate for gestation children. Longer birth length was associated with a thicker subfoveal choroid (2 [1-4] μm/cm, P = 0.005). Macular choroidal thickness at 16 extrafoveal locations was measured in a subset of children and found to have the same associations with birth weight as the subfoveal choroidal thickness.

CONCLUSIONS: In 11- to 12-year-old children, thinner choroids were associated with lower birth weight, lower birth length, and being small for the gestational age.