Evaluating the long-term effects of anti-vascular endothelial growth factor therapy on choroidal neovascularization in age-related macular degeneration using optical coherence tomography angiography

Abstract

Purpose : Optical coherence tomography angiography (OCTA) allows for precise, non-invasive monitoring of changes to choroidal neovascularization (CNV) structure over time. The short-term effects of anti-vascular endothelial growth factor (anti-VEGF) treatment on CNV morphology is well described, but long-term studies on morphologic changes and correlation of such to the type of CNV have not been conducted. This study aims to determine if different types of CNVs in neovascular AMD (nAMD) behave differently with anti-VEGF treatment as visualized on OCTA.

Methods : AMD Patients with treatment naive type 1, type 2, and type 3 CNVs were retrospectively screened for baseline and follow-up OCTA imaging 10 or more months after initial treatment. Images were graded for CNV type, area, activity, mature versus immature vessels, vessel density, presence of atrophy, atrophy location and area. Growth rate was calculated as the percent change in lesion area from baseline over the years of follow-up. The occurrence of complete regression and the percent of lesions that grew, remained stable, and shrunk per type was also evaluated. Statistical analysis assessed the differences in features across types and the correlation of these variables with growth rate and the number of injections.

Results : Forty-five eyes from 43 patients with a mean follow-up of 2 years (± 1 year) were evaluated. Twenty-seven lesions were classified as pure type 1 CNVs, 13 CNVs had a type 2 component, and 5 CNVs had a type 3 component. Of these cases, two mixed-type CNVs were considered to have completely regressed. Most type 1 and all type 3 CNVs (43% and 100%, respectively) shrunk while most type 2 CNVs (45%) grew in the follow-up. There was no difference in the magnitude of growth rate across type. The growth rate of type 3 CNVs was inversely correlated with the number of injections (p < 0.001, ρ =1).

Conclusions : Complete regression of a CNV network exposed to anti-VEGF in nAMD is rare. Analysis of this data found no difference in the magnitude of growth rate across type, and no significant effect from varying anti-VEGF exposure in type 1 and type 2 lesions. This work highlights the differences between type 1 and 2 CNVs versus type 3 lesions and emphasizes the role of anti-VEGF as anti-leakage rather than vascular regression agents in nAMD.

This is a 2020 Imaging in the Eye Conference abstract.