Using Ultrawide Field-Directed Optical Coherence Tomography for Differentiating Nonproliferative and Proliferative Diabetic Retinopathy

PURPOSE: To evaluate the ability of ultrawide field (UWF)–directed optical coherence tomography (OCT) to detect retinal neovascularization in eyes thought to have severe nonproliferative diabetic retinopathy (NPDR). METHODS: Retrospective study of 20 consecutive patients diagnosed with severe NPDR by clinical examination. All patients underwent UWF color imaging (UWF-CI) and UWF-directed OCT following a prespecified imaging protocol to assess the mid periphery, 15/32 (46.9%) eyes underwent UWF–fluorescein angiography (FA). On OCT, new vessels elsewhere (NVE) were defined when vessels breached the internal limiting membrane. RESULTS: A total of 32 eyes of 20 patients were evaluated. Of the 45 suspected areas of intraretinal microvascular abnormalities (IRMA) on UWF-CI, 38 (84.4%) were imaged by UWF-directed OCT, and 9/38 IRMA (23.7%) were NVE by OCT. Furthermore, UWF-directed OCT identified seven additional NVE in three eyes not seen on UWF-CI. This resulted in a change in diabetic retinopathy (DR) severity from severe NPDR to PDR in 8/32 eyes (25.0%). Among the 46.9% of eyes with UWF-FA, UWF-directed OCT agreed with the UWF-FA findings in 80% (12/15 eyes), missing only one peripheral NVE outside the UWF-OCT scanning area. Two eyes had subtle NVD that were not evident on UWF-directed OCT. CONCLUSIONS: This pilot study suggests that UWF-directed OCT may help differentiate IRMA from NVE and detect unrecognized NVE in eyes with advanced DR in a clinical practice setting. Future prospective studies in larger cohorts could determine whether this rapid and noninvasive method is clinically relevant in determining NVE presence or retinopathy progression and complication risk. TRANSLATIONAL RELEVANCE: UWF-directed OCT may offer a noninvasive alternative to detect NVE in eyes with DR.