Figure 2

Representative 6 × 6 mm en face deep capillary plexus (DCP) optical coherence tomography angiography (OCTA) images with application of neutral density filter (NDF) of a 35-year-old healthy male subject. Signal strength (SS) decreased significantly for spectral domain OCTA (SD-OCTA) compared to swept-source OCTA (SS-OCTA). The boundaries of the fovea avascular zone became unclear (yellow arrowhead), and projection of overlying retinal vessels was faint (yellow arrow) when SS decreased. These features were more prominent for SD-OCTA than for SS-OCTA. For SD-OCTA, the vessel density (VD) was 39.3%, 37.8%, and 37.8%, and the vessel length density (VLD) was 11.1%, 10.8%, and 11.0% when SS decreased, respectively. For SS-OCTA, the VD was 33.7%, 34.1%, and 31.6%, and the VLD was 12.5%, 12.3%, and 11.4%, respectively.