3 D OCT angiography in choroid layer

Summary: Purpose To study the three-dimensional organization of choroidal neovascularization complicating age-related macular degeneration (nAMD). Design: Observational, cross-sectional study. Methods: Eyes were analyzed using high-speed swept-source OCT-A. Raw data was processed automatically to obtain three-dimensional models of choroidal neovascularization blood flow. Quantitative parameters analyzed included blood flow volume, vessel segment length and fractal dimension (FD). Raw data processing algorithms were built in Matlab coding language and model analysis performed using Imaris software. Results: Twenty patients of whom 10 (10 eyes) were in Group 1 (treatment naïve active nAMD) and 10 (10 eyes) in Group 2 (remission nAMD) based on SD-OCT qualitative morphology and multimodal imaging. CNV vessel branches showed statistical self-similarity and a lognormal distribution. Treatment naïve networks were smaller, denser and more disorganized comparing to networks of inactive disease (p < 0.01). Conclusions: Blood flow characteristics on OCT-A can be accurately studied using three-dimensional metrics. In the future, volumetric OCT-A quantitative parameters could potentially help assess CNV activity status.