VOLUMETRIC THREE-DIMENSIONAL OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF RETINAL NEOVASCULARIZATION IN PROLIFERATIVE DIABETIC RETINOPATHY

Supplemental Digital Content is Available in the Text. Volumetric three-dimensional optical coherence tomography angiography with multiple image averaging may be useful for analyzing the structure and flow parameters of retinal neovascularization in proliferative diabetic retinopathy. Purpose: To evaluate structural and angiographic neovascularization in patients with proliferative diabetic retinopathy using volumetric three-dimensional optical coherence tomography angiography (OCTA). Methods: This prospective, observational cross-sectional study included 29 eyes of 27 patients with proliferative diabetic retinopathy. The angiogenic structure, feeding vessel (epicenter), flow volume, and flow volume density of the neovasculatures were evaluated using three-dimensional OCTA imaging. The flow area and the flow area density were also measured using en face OCTA imaging. Results: Sites of neovascularization were imaged successfully in 17 of the 29 eyes (58.6%). Three proposed types of neovascularization were identified on the basis of structural features seen on the three-dimensional OCTA images. Neovascularization of the adhesion type (9 of 17, 52.9%) adhered to the retinal vasculature. Those of the traction type (5 of 17, 29.4%) were partially separated from the retinal vascular plexus. Those of the mushroom type (3 of 17, 17.6%) were connected to the retinal vasculature by several epicenters. There was a significant difference between highly leaky (active) and faintly leaky (inactive) neovascularization for flow volume density, but not for flow area, flow volume, or flow area density (P = 0.01, 0.9, 0.6, and 0.1, respectively). Conclusion: Volumetric three-dimensional OCTA revealed three types of neovascularization in proliferative diabetic retinopathy and may be useful for assessing neovascular activity and planning vitrectomies.