Visualizing Three-Layered Perifoveal Retinal Vasculature in Preterm Infants Using Handheld Optical Coherence Tomography Angiography

Abstract

Purpose : Current understanding of retinal vascular development is largely based on histopathological studies of rare postmortem fetal eyes and by inference from non-human primates. Recent technological advances in handheld optical coherence tomography angiography (OCT-A) offer opportunity for direct imaging of the in vivo human retinal vascular development in preterm infants. Our goal is to establish offset parameters for macular microvasculature segmentation and visualize the three-layered perifoveal retinal vasculature in preterm infants using handheld OCT-A.

Methods : In this exploratory study, preterm infants were imaged using an investigational noncontact, handheld swept-source OCT-A device (UC3) under an IRB-approved protocol. Imaging occurred either at the bedside non-sedated or during examination under anesthesia with pharmacological pupillary dilation. 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 : We selected six high-quality OCT-A volumes in two infant age groups for analysis and optimized offset parameters for vascular plexus visualization. A three-layered perifoveal retinal vasculature was successfully visualized in all three preterm infants in the 40 weeks postmenstrual age (PMA) group. No obvious ICP or DCP was found in the preterm infants in the 35 weeks PMA group, all of whom had retinopathy of prematurity (ROP).

Conclusions : Custom OCT-A segmentation parameters can be used to visualize the three-layered perifoveal retinal vasculature in preterm infants at term equivalent age. Prior to formation of the ICP and DCP, the perifoveal vasculature may be better visualized in two layers. Depth-resolved OCT-A of perifoveal retinal vasculature in preterm infants will inform human retinal vascular development and vascular pathologies of ROP.

This is a 2021 ARVO Annual Meeting abstract.

 

A colored composite for the three vascular plexuses in a preterm infant eye at 40 weeks postmenstrual age. Superficial capillary plexus: yellow; intermediate capillary plexus: cyan; and deep capillary plexus: magenta.