Semiautomated measures of foveal immaturity from handheld swept-source optical coherence tomography are associated with retinopathy of prematurity severity.

Background/aims: Handheld swept-source optical coherence tomography (SS-OCT) was previously used to measure foveal maturity through semiautomated methods in awake premature infants. This study assesses the relationship between foveal maturity and retinopathy of prematurity (ROP) severity.

Methods: This is a prospective, observational study using handheld SS-OCT imaging of premature infants undergoing ROP screening. A semiautomated segmentation algorithm measured foveal angle, total retinal cross-sectional area, and retinal and choroid thicknesses at the fovea and parafovea, excluding significant macular oedema. Measures were correlated with ROP severity using a mixed model approach.

Results: 99 eye imaging sessions from 26 preterm infants were included. Average birth weight was 1057.6±324.8 g. Gestational age and postmenstrual age at imaging were 29.1±3.0 and 36.1±3.8 weeks, respectively. Stage 3 ROP occurred in 16/99 (16.2%) exams. Shallow foveal angle and higher inner retinal fovea/parafoveal (F/P) ratio correlated with more posterior ROP zone (zone 2: 119.2°±20.9° vs zone 3: 96.5°±16.7° and zone 2: 0.6±0.2 vs zone 3: 0.4±0.1, respectively, both p<0.001). Inner retinal F/P ratio was greater in eyes with higher ROP stage (stage 3: 0.6±0.2 vs stage 0 or mature: 0.4±0.2, p=0.03) but this relationship was not seen for outer retina (p=0.29). Larger retinal cross-sectional area coincided with worse ROP stage (stage 3: 1.9±0.06 mm² vs stage 0 or mature: 1.6±0.04 mm², p<0.001) and zone (zone 2: 1.6±0.04 mm² vs zone 3: 1.7±0.04 mm², p=0.01).

Conclusions: SS-OCT semiautomated measurements of inner retinal F/P ratio, foveal angle and retinal cross-sectional area may serve as ROP severity biomarkers.