Morphological differences between optic disc collaterals and neovascularization on optical coherence tomography angiography

BackgroundTo study morphological features of optic disc venous collaterals (OVCs) and neovascularization of optic disc (NVD) on optical coherence tomography angiography (OCTA).MethodsPatients with OVCs and NVDs secondary to ischemic retinal diseases were prospectively enrolled. Multimodal imaging was performed using color fundus photography, fluorescein angiography (FA), and OCTA. Morphological evaluation of en-face structural OCT, cross-sectional and en-face OCTA was performed.ResultsTwenty eyes (20 patients; OVCs: n = 10 and NVD: n = 10) were included. OVCs appeared as small, loopy vessels distinct from surrounding peripapillary capillaries on OCTA in the radial peripapillary capillary frame. NVDs appeared as a mesh of fine caliber, raised vessels best seen in the vitreous slab of OCTA. Flow signals in these vascular alterations correlated well with hyperfluorescence on FA.ConclusionsOCTA provides improved visualization of NVDs and OVCs in ischemic retinal diseases such as diabetic retinopathy and retinal vein occlusions compared to conventional FA.