A recent study published in Ophthalmology and Therapy highlighted the role of widefield optical coherence tomography in assessing disease severity and extent.
In context to morphology and clinical implications, retinal neovascularization in proliferative diabetic retinopathy (PDR) varies. The study aimed to classify retinal neovascularization into subtypes and determine their relationship with the ischemic index using widefield optical coherence tomography (OCT) angiography.
Fifty treatment-naïve patients (84 eyes) with PDR were included in a retrospective observational study, during which they underwent widefield optical coherence tomography angiography (WF-OCTA; Plex Elite 9000) and widefield fundus photography (CLARUS 500™) between January 2022 and June 2024. WF-OCTA images were used for quantitative analysis of ischemic index (ISI), capillary nonperfusion (CNP), and three neovascularization (NV) subtypes. Type 1 NV (flat, intraretinal or subinternal limiting membrane growth), type 2 NV (preretinal proliferation extending into the vitreous), and type 3 NV (a combination of types 1 and 2 features, showing both flat and protruding components). Using ImageJ software, two clinicians manually delineated capillary nonperfusion (CNP). Nonperfusion area, ischemic index (ISI), need for adjunctive interventions (additional laser or vitreoretinal surgery), and best corrected visual acuity (BCVA) were related to treatment response to panretinal photocoagulation (PRP).
A higher frequency of Type 1 neovascularization, 42.1%, was found with a mean ischemic index (ISI) of 0.19 ± 0.17. The highest ISI (0.27 ± 0.07) was observed in Type 3 neovascularization. After panretinal photocoagulation, 58% of patients experienced an increase in best corrected visual acuity (BCVA), with Type 3 showing the greatest improvement. Adjunct laser therapy was more frequently required for Type 2 (13 cases) following standard panretinal photocoagulation, while Type 3 required the least supplemental laser.