Assessment of Exudative Activity of Choroidal Neovascularization in Age-Related Macular Degeneration by OCT Angiography

Purpose: Based on exudative activity, choroidal neovascularization (CNV) in age-related macular degeneration (AMD) can be classified as "active" aCNV, pretherapied "silent" sCNV (i.e., a treatment-free interval >12 weeks), or treatment-naive "quiescent" qCNV. We evaluated the qualitative and quantitative optical coherence tomography angiography (OCTA) features of these CNV subgroups. Methods: The presence of small-caliber vessels, peripheral arcades, and a perilesional OCTA signal attenuation as well as values for vessel length, density, and branching index were evaluated for each CNV network in a 6 x 6 mm OCTA scan pattern. Results: Fifty-one eyes of 51 patients with AMD (age 75.9 +/- 7.5 years; 20 males [39.2%]) were included. The qCNV subgroup (n = 8) showed the highest prevalence of qualitative and quantitative values for OCTA activity criteria, reaching significance with regard to small-caliber vessels (p = 0.003), peripheral arcades (p = 0.039), vessel length (p = 0.020), and branching index (p < 0.001) when compared to the aCNV (n = 32) and sCNV (n = 11) subgroups. Qualitative criteria were inversely associated with the number of previous anti-VEGF injections (each p < 0.03), while quantitative metrics also suggested lower values. Conclusions: These findings suggest that OCTA may be supportive in the phenotypical differentiation of CNV lesions secondary to AMD, while the assessed structural changes appeared to be more indicative of previously administered anti-VEGF therapy than current exudative activity.