Choriocapillaris Flow Deficits Around Geographic Atrophy Correlate with Enlargement Rates Based on Swept Source OCT Angiographic Imaging

Abstract

Purpose : To determine if the enlargement rates (ERs) of geographic atrophy (GA) correlated with the percentage and size of choriocapillaris (CC) flow deficits (FDs) surrounding GA, we imaged the FDs and the ERs of GA using swept source optical coherence tomography (SS-OCT).

Methods : Patients with GA secondary to non-exudative AMD were imaged using a 100-kHz SS-OCT instrument (PLEX Elite 9000, Carl Zeiss Meditec). A 6x6mm scan pattern was performed. GA area measurements were obtained from en face SS-OCT sub-RPE slab images. Visualization of the CC and quantification of FDs were performed using SS-OCT angiography (SS-OCTA). The percentage of CC FDs (FD%) and the average FD area measurements were calculated in regions surrounding the GA.

Results : In 22 eyes of 15 patients, the annual square root ERs for GA ranged from 0.07 to 0.75 mm/year. The highest FD values were found in the region closest to the margin of GA. The strongest correlations were found between the ERs and average CC FD area measurements away from the margin of GA and calculated from the total scan area minus the area of GA (p<0.001).

Conclusions : Contrary to expectations, the strongest correlations between the ER of GA and CC FDs were found when the entire scan area minus the area of GA was used rather than the region immediately around the GA.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.