Exploratory investigation of OCTA-VISTA for longitudinal monitoring of neovascular age-related macular degeneration treatment.

PURPOSE: This study investigated the feasibility of a quantitative blood flow measurement program combining optical coherence tomography angiography (OCTA) and variable interscan time analysis (VISTA) in neovascular age-related macular degeneration (nAMD) treatment. METHODS: A prototype OCT device with a unique scan pattern acquired OCTA-VISTA images from 11 eyes of 10 patients with treatment-naïve nAMD and macular neovascularization (MNV) at three time points: pretreatment, immediately posttreatment, and 1 month later. MNV regions were segmented from the outer retinal slab. Blood flow parameters, which were surrogate markers of velocity, and neovascular vessel area (NVA) were evaluated. Characteristic changes were analyzed in the MNV vessels, which were classified by diameter as follows: capillaries (≤ 20 μm), medium vessels (20–40 μm), and large vessels (≥ 40 μm). RESULTS: Quantitative analysis was feasible in five eyes from five patients. In eyes with marked NVA reduction, flow parameters decreased from baseline to 1 month by 37.9% in capillaries, 39.7% in medium vessels, and 48.3% in large vessels. In partial responders with limited NVA changes, the corresponding reductions were 29.6%, 23.5%, and 14.2%, respectively. Scatter plot analyses demonstrated that changes in NVA and flow parameters generally occurred in parallel. CONCLUSIONS: OCTA-VISTA enabled quantitative tracking of flow parameters by vessel diameter before and after MNV treatment in some patients. This methodology may benefit treatment efficacy monitoring and evaluating disease progression in nAMD.