Quantifying choriocapillaris hypoperfusion in patients with choroidal neovascularization using swept-source OCT angiography

Cathrine M Keiner,1 Hao Zhou,2 Qinqin Zhang,2 Ruikang K Wang,2 Nicholas T Rinella,1 Catherine E Oldenburg,1,3 Jacque L Duncan,1 Daniel M Schwartz11Department of Ophthalmology, University of California, San Francisco, CA, USA; 2Department of Bioengineering, University of Washington, Seattle, WA, USA; 3Francis I. Proctor Foundation, University of California, San Francisco, CA, USACorrespondence: Daniel M SchwartzDepartment of Ophthalmology, University of California, 10 Koret Way, San Francisco, CA 94117, USATel +1 415 476 1152Email dan.schwartz@ucsf.eduPurpose: To compare choriocapillaris flow voids (FV) in patients with neovascular age-related macular degeneration (AMD) with age-matched normal controls using swept-source optical coherence tomography angiography (SS-OCTA).Patients and methods: Eleven eyes of 11 subjects with neovascular AMD and 11 eyes of 11 age-similar normal subjects were imaged using SS-OCTA with a 6x6mm scanning pattern. Choriocapillaris FV, defined as a percentage of regions determined to have flow deficits divided by the total scanned region, was measured using a one standard deviation thresholding algorithm developed from a database of age-similar normal subjects.Results: Choriocapillaris FV was more extensive in patients with choroidal neovascularization (CNV) compared to age-similar normal subjects (FV: 20.56±4.95, 95% CI: 17.64–23.49 vs FV: 10.95±2.08, 95% CI: 9.73–12.18, respectively; P=0.0001). FV within a two-degree margin surrounding CNV in wet AMD subjects (FV: 35.04±9.34; 95% CI: 29.52–40.56) was increased compared to normal subjects (P