Depth-Resolved Visualization of Perifoveal Retinal Vasculature in Preterm Infants Using Handheld Optical Coherence Tomography Angiography.

Purpose To establish methods to visualize depth-resolved perifoveal retinal vasculature in preterm infants using handheld optical coherence tomography angiography (OCT-A). Methods In this exploratory study, eyes of preterm infants were imaged using an investigational noncontact, handheld swept-source OCT-A device as part of the prospective BabySTEPS infant retinal imaging study. We selected high-quality OCT-A volumes at two developmental stages for analysis. Customized MATLAB scripts were used to segment retinal layers, test offset parameters, and generate depth-resolved OCT-A slabs. The superficial (SCP), intermediate (ICP), and deep (DCP) capillary plexuses were visualized and qualitatively assessed by three image graders. Results Six eyes from six preterm infants were included in this analysis. A three-layered perifoveal retinal vasculature was successfully visualized in all three eyes (three infants) in the 40 weeks postmenstrual age (PMA) group (one of three eyes with treated type 1 retinopathy of prematurity [ROP]). No obvious ICP or DCP was found in good-quality scans of the three eyes (three infants) in the 35 weeks PMA group (three of three eyes developed type 1 ROP). Conclusions Custom segmentation parameters are useful to visualize perifoveal retinal vasculature in preterm infants. At term age, a three-layered capillary structure is visible in most eyes, while prior to detectable flow within the ICP and DCP, the perifoveal vasculature may be better visualized in two layers. Translational relevance Development of segmentation parameters for depth-resolved OCT-A of perifoveal retinal vasculature in preterm infants facilitates the study of human retinal vascular development and vascular pathologies of ROP.