Handheld Optical Coherence Tomography Angiography Findings in Preterm Infants with Retinopathy of Prematurity

Abstract

Purpose : Prior imaging studies in pediatric patients with history of preterm birth compared to age-matched children revealed a smaller foveal avascular zone (FAZ). However, how these retinal capillaries were formed during development remained unclear. The advent of bedside handheld optical coherence tomography angiography (OCT-A) imaging provides us an opportunity to observe in situ the formation of these retinal vasculature in eyes of preterm infants with retinopathy of prematurity (ROP).

Methods : Under an IRB-approved protocol, we used an investigational handheld noncontact swept source OCT system to conduct OCT-A imaging in awake non-sedated preterm infants at the bedside and follow-up care in clinic, as well as preterm infants undergoing exam under anesthesia (EUA) with ROP. The superficial and deep vascular complex (SVC and DVC) were segmented at the fovea and en face OCT-A images were generated using customized MATLAB scripts.

Results : We imaged at the bedside, in clinic and under EUA 25 preterm infants ranging between 31 to 45 weeks postmenstrual age. Despite a smaller FAZ in the SVC, we captured different sizes of central avascular area of DVC at the posterior pole in the developing infant eyes. In three eyes, the increased size of the DVC avascular zone appeared to correlate with the presence of macular edema. Dilated DVC capillary endings were also observed in areas of macular edema. Other findings include a relative avascular DVC area immediately surrounding a large retinal vein. Quality of the OCT-A scans were affected by motion and focus adjustment.

Conclusions : OCT-A images from preterm infants with ROP revealed different stages of SVC and DVC formation. More systemic and longitudinal imaging are needed to determine if our observations are physiological as a part of normal/delayed retinal vascular development or pathological.

This is a 2020 ARVO Annual Meeting abstract.

 

Perifoveal retinal vasculature imaged in a preterm infant born at 26 weeks gestational age and imaged at 42 weeks postmenstrual age using the investigational handheld swept source imaging system at the bedside. (A) En face OCT-A image of the perivascular capillaries in the right eye. (B) Cross-sectional B-scan of the same eye showed macular edema with large cysts within the inner nuclear layer. (C) OCT-A image of the SVC identified a small FAZ. (D) OCT-A image of the DVC showed decreased flow signal in a central area larger than the FAZ.