OCT Angiography in Young Children with a History of Retinopathy of Prematurity

Abstract

To describe the size and appearance of the foveal avascular zone (FAZ) in the superficial and deep plexus in young children with treated or spontaneously regressed retinopathy of prematurity (ROP), in comparison with age-matched controls and young adults, as seen with OCT angiography (OCTA), and to compare these parameters with foveal classic OCT images and visual function. Prospective, cross-sectional study. Twenty-five children with treated or spontaneously regressed ROP (mean 5.0±0.8 years) compared with 15 healthy term-born age-matched children and 20 healthy adults. OCTA was performed using a DRI OCT Triton (Swept Source OCT, Topcon, Oakland, NJ). The best-quality images of 1 eye per patient were analyzed. Superficial FAZ and deep FAZ were analyzed separately. Single-scan OCTs were performed using a Spectralis SD-OCT (HRA+OCT, Heidelberg Engineering, Heidelberg, Germany). The foveal pit characteristics and the degree of macular developmental arrest (MDA), defined as the ratio of the outer nuclear layer+ external limiting membrane (ONL+) and the inner retinal layers in the fovea (ONL+/IRL-ratio), were analyzed with a custom-made automated layer segmentation tool (DiOCTA, copyright by Justus-Liebig-University, Giessen, Germany). Visual acuity (VA) was tested with Early Treatment of Diabetic Retinopathy Study letter charts. The ONL+/IRL-ratio, superficial FAZ area, deep FAZ area, foveal parameters, and VA. Foveal pit depth and area were significantly reduced in both treated and spontaneously regressed ROP, whereas the foveal diameter was comparable in all groups. OCTA showed a significantly narrowed superficial FAZ in eyes with treated and spontaneously regressed ROP. In contrast, the deep FAZ was of comparable size in all groups. A reduced superficial FAZ significantly correlated with reduced ONL+/IRL-ratio, and thus the degree of MDA. In treated and spontaneously regressed ROP, reduced superficial FAZ and MDA correlated significantly with diminished VA. OCTA is feasible in young children with a history of ROP and without neurodevelopmental delay. It allows detecting a decreased superficial FAZ size noninvasively. A small superficial FAZ, reduced ONL+/IRL-ratio as a measure of MDA, and reduced VA are concurrent factors in preterm children who are otherwise neurologically normal.