Slab Selection May Impact Tie Between CC Flow Deficits & GA Enlargement Rate In

In eyes with geographic atrophy (GA), slab selection for quantification of choriocapillaris (CC) flow deficits percentage may have a considerable impact on quantitative results, according to a study published in Eye. SriniVas R. Sadda, MD, and colleagues assessed the impact of changing slab position on the correlation between CC flow deficits in eyes with GA and GA yearly enlargement rate (yER). The study team obtained OCT and OCTA images from patients with GA who underwent OCTA scan at baseline and two OCT scans, one at baseline and one after at least 12 months. The researchers marked on en-face fundus image to calculate yER. Sadda and colleagues generated OCTA images from three 10 μm thick slabs 11, 21 and 31 μm posterior to RPE-fit line. For the 11-21 μm slabs, flow deficits percentage was not correlated with yER (P>0.05). Fow deficits percentage of rings in the 600 μm region around GA was correlated with yER (P<0.05). In all slab locations, however, there was no notable correlation between yER and CC flow deficits percentage of rings in the area beyond the 600 μm region (P>0.05).