BackgroundTo compare vitreous angiomosaic images (VAMIs), obtained by widefield swept-source optical coherence tomographic angiography (wfSS-OCTA) and the image of fluorescein fundus angiography (FFA) in the identification of retinal neovascularization (NV) in patients with diabetic retinopathy (DR).MethodsIn this prospective observational study, severe non-proliferative diabetic retinopathy (NPDR) or proliferative DR (PDR) patients were included. All patients underwent FFA and wfSS-OCTA. The number of NVs identified by wfSS-OCTA VAMIs using five fixations 12 × 12 mm montage scans and the resembling FFA images were compared.ResultsFifty-three eyes of 29 patients were enrolled. NVs were detected in 25 eyes by using FFA, including 9 NVs of the disc (NVDs) and 72 NVs elsewhere (NVEs), and in 29 eyes by OCTA, including 11 NVDs and 90 NVEs. The detection rate of NV and NVD of OCTA was comparable to that of FFA (p > 0.05), and the level of agreement was excellent (κ = 0.850, κ = 0.754). Using FFA as the gold standard, the sensitivity for detection of NV by OCTA was 100.0%, specificity was 85.7%, the positive-predictive value was 86.2%, and the negative-predictive value was 100.0%. Compared with FFA, OCTA was superior in terms of the number of NVEs identified (p = 0.024). When we excluded images of patients treated with anti-vascular endothelial growth factor (VEGF) intravitreal therapy for < 3 months, OCTA was comparable to FFA in terms of the number of NVEs discovered (p= 0.203), with excellent agreement (intraclass correlation coefficient = 0.941).ConclusionsWfSS-OCTA is an independent non-invasive alternative to FFA for NV discovery, NVD detection, and individual NVE identification, particularly in patients with PDR who have a history of prior treatment with anti-VEGF.