Abstract
Purpose :
The optic nerve head is incompletely developed at birth and continues to grow postnatally. Recent advancements in noncontact handheld optical coherence tomography (OCT) enable us to directly image the optic nerve head at the bedside. Our goal is to quantify optic disc development in preterm infants using OCT-generated disc diameter (DD), disc-fovea distance (DF), and DD:DF (same parameters used to evaluate for the presence of optic nerve hypoplasia).
Methods :
In this retrospective cohort study, we analyzed bedside OCT scans of the left eye that were captured during the prospective BabySTEPS study. We included imaging sessions that occurred between 30 and 50 weeks postmenstrual age (PMA), occurred prior to retinopathy of prematurity (ROP) treatment, and captured the fovea and both edges of the Bruch’s Membrane Opening (BMO) on a single OCT volume. Graders marked the BMO and fovea using custom infant-specific software. We performed cross-sectional analysis on 36 eyes with OCT scans acquired at 36±1 weeks PMA and longitudinal analysis on 29 eyes with at least three scans between 30 and 50 weeks PMA. We evaluated the change in DD, DF, and DD:DF ratio over time and their associations with the following demographic and ROP characteristics: gestational age, birthweight, sex, maternal race, maternal parity, and ROP stage at imaging.
Results :
Mean gestational age (GA) was 27.3±2.6 weeks for the cross-sectional cohort and 26.5±2.3 weeks for the longitudinal cohort. In the cross-sectional analysis, GA was significantly correlated with DF (r=-0.39 [-0.64, -0.07], p=0.02) and DD:DF (r=0.49, 95% [0.20, 0.71], p=0.002). Infants with ROP stage 0-1 had significantly smaller DF (4169±337 vs. 4394±279 µm, p=0.04) and significantly larger DD:DF (0.25±0.03 vs. 0.23±0.02, p=0.02) than those with ROP stage 2-3. In the longitudinal analysis, DD increased by 20.5±0.9 µm/week (p<0.001), DD:DF increased by 0.0044±0.0003 per week (p<0.001), and DD:DF correlated with GA (0.0047±0.0019 per gestational week, p=0.02).
Conclusions :
In premature children in the early few weeks of life, DD:DF is frequently less than 0.35 which meets the current definition of optic nerve hypoplasia. However, it slowly increases and normalizes with growth. Future larger studies are necessary to verify these conclusions.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.