Analysis of Progressive Neovascularization in Diabetic Retinopathy Using Widefield OCT Angiography

Abstract

To document enlarged neovascularization elsewhere (NVE) quantitatively and morphologically using widefield swept-source (SS) OCT angiography (OCTA) with vitreoretinal interface (VRI) slab images. Retrospective, observational imaging study. The study included 46 NVE examples in 25 eyes of 21 consecutive patients who demonstrated severe proliferative diabetic retinopathy with NVE between March 2018 and June 2020 at Osaka University Hospital. All patients underwent ophthalmologic examination, including ultra-widefield fluorescein angiography and widefield SS OCTA scans. We evaluated the area and the vascular density (VD) of NVE lesions detected on five 12× 12-mm2 or two 15× 9-mm2 SS OCTA panoramic VRI slab images obtained at the first and final visits. At baseline, the mean NVE area on OCTA was 1.85 ± 2.81 mm2, and the VD of the NVE lesions was 73.9 ± 14.6%. At the final visit, the mean NVE area on OCTA was 2.14 ± 3.14 mm2, and the mean VD of the NVE lesions was 65.3 ± 17.1%. The average NVE size change (square millimeters per month) was associated significantly with the ischemic index (P= 0.009). Growth of NVE area was classified into 2 patterns: round (61.8%) and ramified (38.2%). The round group tended to have a larger ischemic index at baseline than the ramified group (P= 0.0375). We quantified the size and density of NVE lesions over time. The NVE size increase was associated significantly with the severity of ischemic changes. Furthermore, the round growth pattern was correlated significantly with the ischemic index. These findings suggest that the morphologic features of NVE are associated with more severe ischemia.