Systemic Factors Associated with a Thinner Choroid in Preterm Infants

Purpose To identify systemic health factors associated with a thinner choroid, which has been hypothesized as a cause of poor visual outcomes in low-birth weight infants.Design The prospective, observational Study of Eye Imaging in Preterm Infants (BabySTEPS) enrolled infants recommended for retinopathy of prematurity screening based on the American Association of Pediatrics guidelines.Participants Infants who underwent imaging with investigational handheld OCT at 36 ± 1 weeks' postmenstrual age (PMA) as part of BabySTEPS.Methods Average choroidal thickness was measured across the central subfoveal 1 mm. We concurrently collected maternal and infant clinical health data. Univariate and multivariate linear regression analyses were performed to evaluate factors associated with choroidal thickness. The left and right eyes showed similar thicknesses, so their average was used for analysis.Main outcomes measures Association between infant health factors and subfoveal choroidal thickness.Results Subfoveal choroidal thickness was measurable in 82 of 85 infants and 94% of eyes. Mean choroidal thickness was 231 ± 78 μm. In the univariate analysis, a thinner choroid was associated with decreased growth velocity (P P P P = 0.01), the presence of patent ductus arteriosus (P = 0.05), sepsis or necrotizing enterocolitis (P = 0.03), bronchopulmonary dysplasia (P = 0.03), pulmonary interstitial emphysema (P = 0.002), more days on oxygen support (P P P P = 0.002) and oxygen support at the time of OCT imaging (P = 0.004) remained associated with a thinner choroid.Conclusions A thinner choroid is associated independently with growth velocity and receiving oxygen support at 36 ± 1 weeks PMA. This suggests that choroidal development in preterm infants may be related to growth rate in the first weeks of life and the prolonged use of supplemental oxygen. Longitudinal studies are needed to assess differences in choroidal thickness before 36 weeks PMA and to assess their impact on visual outcomes.