Retinal Vessel Density in Exudative and Nonexudative Age-Related Macular Degeneration on Optical Coherence Tomography Angiography

Abstract

Although the choroid contributes to the pathogenesis of age-related macular degeneration (AMD), the role of retinal perfusion is unclear. We sought to compare retinal vascular measurements between eyes with nonexudative and exudative AMD using optical coherence tomography angiography (OCT-A). Retrospective, cross-sectional study. OCT-A images were analyzed from 310 eyes of 182 patients (mean age ± standard deviation [SD], 78.8 ± 8.8 years) with nonexudative (54.2%) and exudative (45.8%) AMD to measure retinal vessel density (VD) from the superficial capillary plexus in the foveal, parafoveal, and full macular regions and foveal avascular zone (FAZ) area, perimeter, and circularity. Multivariate regressions were used to compare nonexudative and exudative AMD eyes and the impact of anti-vascular endothelial growth factor (anti-VEGF) treatments or geographic atrophy (GA). In eyes with AMD, VD decreases with age in the foveal (β=-0.211, P < .001), parafoveal (β=-0.305, P < .001), and full macular regions (β=-0.295, P < .001). Eyes with exudative AMD demonstrated lower VD, especially in the parafoveal (29.8% ± 6.3% vs 33.0% ± 5.7%, P < .001) and full regions (27.9% ± 6.2% vs 31.2% ± 5.5%, P < .001) compared with nonexudative AMD. There were no differences in FAZ area, perimeter, or circularity between the 2 groups (P= .503-.907). In eyes with exudative AMD, previous anti-VEGF treatments did not impact retinal vascular measurements (P= .324-.986). Nonexudative AMD severity and presence of central GA also impacted retinal VD and FAZ morphology. Retinal VD is decreased in eyes with exudative AMD compared with nonexudative AMD but is unaffected by anti-VEGF treatments, suggesting a retinal vascular contribution to the pathogenesis of AMD.