Abstract
Purpose :
To compare retinal vessel density in eyes with geographic atrophy (GA) secondary to age-related macular degeneration (AMD) to age-matched healthy eyes using projection-resolved optical coherence tomography angiography (PR-OCTA).
Methods :
Study participants with GA and healthy age-matched controls were enrolled. Macular 3×3-mm2 OCTA scans were obtained with AngioVue system (Optovue, Inc, CA). Exclusion criteria included signal strength index < 55, significant motion artifacts, and diagnosis of diabetes. Structural optical coherence tomography (OCT) and OCTA volumetric scans were exported for custom processing including 3-dimensional projection artifact removal, retinal layer segmentation, and en face angiogram generation. Reflectance compensated vessel densities were calculated on projection-resolved superficial vascular complex (SVC), intermediate capillary plexus (ICP), and deep capillary plexus (DCP). The central 0.6-mm area centered on the fovea was excluded to eliminate variability from foveal avascular zone. Vessel density on each individual plexus was compared between eyes with GA and healthy normal eyes using independent sample t test. En face OCT reflectance was used to identify areas of GA and retinal vessel densities within the GA region were compared to the ones outside of the GA in same macular scan using the paired Student’s t-test.
Results :
Ten eyes with GA and 10 normal control eyes were studied. Mean age of study participants with GA was 81.3±9.3 years, which was similar to the mean age of the 10 normal controls, 76.3±4.2 (P=0.14). Eyes with GA had significantly lower (P<0.05) vessel density in SVC, ICP, and DCP compared to control eyes (Table 1). In eyes with GA, vessel density within the GA region was significantly lower compared to regions without GA in the same scan for the DCP (19.55±3.83 vs. 25.57±2.34, P<0.001) and ICP (30.19±6.25 vs. 35.03 ±1.72, P=0.035). There was a trend towards reduced SVC in the region of GA compared to regions without GA, however this was not significant (50.60±8.79 vs. 55.44± 1.87, P=0.11) (Figure 1).
Conclusions :
PR-OCTA demonstrated that vessel density in all three retinal plexuses (SVC, ICP and DCP) was lower in eyes with GA compared to normal age-matched controls. Vessel density loss was greatest within regions of geographic atrophy.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.