Correlations Between Choriocapillaris and Choroidal Measurements and the Growth of Geographic Atrophy Using Swept Source OCT Imaging

PURPOSE: The correlations between enlargement rates (ERs) of geographic atrophy (GA) and choriocapillaris (CC) flow deficits (FDs), mean choroidal thickness (MCT), and choroidal vascularity index (CVI) were investigated using swept source optical coherence tomography (SS-OCT) in age-related macular degeneration (AMD). DESIGN: Retrospective review of prospective, observational case series. METHODS: Eyes with GA from AMD were imaged with SS-OCT (PLEX(®) Elite 9000; Carl Zeiss Meditec, Inc, Dublin, CA) using 6×6 mm scan pattern. GA lesions were identified and measured using custom en face structural images and annual square root ERs of GA were calculated. At baseline, CC FDs from different regions outside of the GA were measured, and MCT and CVI from the entire scan area were measured. All the measurements were performed using previously published and validated algorithms. RESULTS: Thirty-eight eyes from 27 patients were included. The CC FDs within each region around GA lesions were all highly correlated with ERs of GA (All P < 0.005). CVI inside GA region was correlated with the ERs (P = 0.03), while other choroidal measurements had no significant correlation with the ERs of GA (P > 0.06). CONCLUSION: Statistically significant correlations were found between the ERs of GA and CC FD% from the entire scan region outside the GA and not just the region immediately adjacent to the GA. These results suggest that abnormal CC perfusion throughout the macula contributes to disease progression in eyes with GA. CVI inside GA region could also be a potential indicator for the growth of GA.