Figure 2
Bedside handheld optical coherence tomography angiography (OCTA) images of the preterm infant retinal vasculature in eyes without (A) and with (B and C, same infant, &D) neovascularization. The top row shows the vascular pattern en face, the bottom two rows are cross-sectional B-scans with flow overlay from the top row images at the site of the red lines. OCTA flow signal appears yellow and red in cross-section and sums to create the white vascular pattern of the en face images in the top row. (A) At 36 weeks postmenstrual age (PMA) in an infant who never developed severe ROP, retinal microvasculature was well-formed in the macula with flow signal present from the innermost border of the retina (internal limiting membrane) to the inner nuclear layer/inner plexiform layer junction. Macular edema was visible and common in preterm infants. (B) At 32 weeks PMA in an infant who later required treatment for severe ROP, prominent vascular flow was observed in the perifoveal region, with focal mild elevation of the inner retinal surface (asterisk). (C) Two weeks later (at 34 weeks PMA), the same eye as in (B) developed severe (aggressive) ROP that required treatment. The inner retinal neovascularization produced greater elevation and splitting of the internal limiting membrane / nerve fiber layer on either side of the fovea (F), and now breached the internal limiting membrane in the inferior macula (arrowhead), assuming an early extraretinal neovascular bud configuration. (D) At 34 weeks in an infant who required treatment of severe ROP one week later, an extraretinal neovascular bud (arrowhead) exhibited flow signal extending above the inner retinal surface over a larger retinal vessel posterior to the margin of vascularized retina. Neovascular flow signals also extended into the preretinal tissue at the vascular-avascular junction (open arrowhead).
