Longitudinal Choroidal Development in Preterm Infants

Abstract

Purpose : While much is known about the timeline of retinal vascular development in preterm infants, little is known about the developmental trajectory of the choroid. We characterized changes in choroidal thickness from 30 to 60 weeks postmenstrual age (PMA) using optical coherence tomography imaging (OCT) in preterm infants.

Methods : Infants underwent imaging with investigational hand-held OCT as part of the prospective, observational, IRB-approved Study of Eye Imaging in Preterm InfantS (BabySTEPS). Average choroidal thickness across the central subfoveal 1 millimeter in each eye at each time point was measured using custom segmentation software. Eyes imaged at three or more distinct time points between 30 and 60 weeks PMA were included in the analysis. A segmented mixed model was used to analyze the change in choroidal thickness as a function of PMA.

Results : We included 1159 imaging sessions of 85 preterm infants (166 eyes). Average gestational age was 27.7 ± 2.6 weeks. Between 30 and 60 weeks PMA, choroidal growth follows a biphasic model, with a linear growth rate of 13.9 µm per week (95% confidence interval 12.8-14.0 µm) from 30 weeks until 38.2 weeks then cessation of growth, with a growth rate of -0.20 µm per week (95% confidence interval -1.48 to 1.07 µm) from 38.2 weeks to 60 weeks. Mean (±standard deviation) of choroidal thickness was 151.8 ± 38.9 µm at 31±1 weeks, 274.1 ± 86.0 µm at 41±1 weeks, and 301.0 ± 82.4 µm between 50 and 60 weeks.

Conclusions : The choroid experiences rapid linear growth from 30 weeks PMA until 38 weeks PMA, at which time the choroidal thickness is similar to that of a healthy adult. These foundational measurements will be essential as we learn more about choroidal development in preterm infants and the role of the choroid in ocular and retinal health.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.