Optical coherence tomography angiography markers associated with treatment response in neovascular age-related macular degeneration

Purpose: To investigate whether qualitative and quantitative features of choroidal neovascular membranes are associated with anti-vascular endothelial growth factor treatment response in patients with neovascular age-related macular degeneration. Methods: A total of 41 eyes were included in this cross-sectional observational study and divided into “good responders” and “poor responders” based on the long-term functional changes, frequency of recurrent choroidal neovascular activity, and injection need. Enface optical coherence tomography angiography images were obtained and qualitative features of choroidal neovascular membranes were described based on vessel network density. Then, quantitative measurements including vessel area, vessel length, junction density, and lacunarity were calculated using validated software (ImageJ and AngioTool). Chi-square tests, t-test, or Mann–Whitney U tests were used for group comparisons, and intraclass correlation coefficients were calculated for reliability assessment of quantitative analyses. Results: Twenty-two eyes treated by a median of 9 (3–24) anti-vascular endothelial growth factor injections at a median follow-up of 41 (12–89) months were categorized as good responders, 19 treated by a median of 26 (11–46) injections at a median follow-up of 44.5 (12–84) months as poor responders. Good responder group mostly had loose network (45.5%), and poor responders mostly had dense network (47.7%). The difference was not statistically significant (p = 0.25). The size of the lesion was 2.7 times greater at baseline (p = 0.04) and 1.7 times greater at final examination in the poor responder group (p = 0.04). Lacunarity index, showing lesion heterogeneity, was higher in good responders (p = 0.018) than poor responders. Other quantitative vascular features did not significantly differ between the groups (p > 0.05). Conclusion: Long-term remodeling of chronically treated choroidal neovascular may be non-invasively and reproducibly investigated using optical coherence tomography angiography. Quantitative analysis and lacunarity index, in particular, may be used as a measure of vessel maturation and guide treatment strategies in neovascular age-related macular degeneration.