Observation of treated iris neovascularization by swept-source-based en-face anterior-segment optical coherence tomography angiography

Abstract

We evaluated regression of iris neovascularization (INV) using en-face anterior-segment optical coherence tomography angiography (AS-OCTA) after anti-vascular endothelial growth factor (VEGF) therapy. Seven consecutive eyes with INV were examined before and after anti-VEGF therapy, and all AS-OCTA scans were obtained using a swept-source OCTA system with an anterior-segment lens adapter. Slit-lamp microscopy photography and anterior indocyanine green angiography also were performed. Quantitative analyses of the vascular density, vascular lacunarity, and fractal dimension on AS-OCTA images were performed. AS-OCTA visualized the INV as signals around the pupillary margin, which corresponded to the vasculature confirmed by slit-lamp microscopy. After anti-VEGF drug injection, regression of INV was observed by AS-OCTA in all eyes (100%). The vascular density decreased and vascular lacunarity increased significantly after anti-VEGF therapy. This pilot study demonstrated the ability of AS-OCTA not only to detect but also to evaluate INV. Further study is warranted to improve the algorithm for delineating the iris vasculature to decrease artifacts.