Clinical Ophthalmology (Aug 2019)

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

  • Keiner CM,
  • Zhou H,
  • Zhang Q,
  • Wang RK,
  • Rinella NT,
  • Oldenburg CE,
  • Duncan JL,
  • Schwartz DM

Journal volume & issue
Vol. Volume 13
pp. 1613 – 1620

Abstract

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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 [email protected]: 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<0.001). FV of the region outside the two-degree margin surrounding CNV (FV: 19.61±6.08, 95% CI: 16.02–23.20) was increased compared to age-similar controls (P=0.0002). In neovascular AMD eyes, FV was greater within two degrees of the margin of CNV than in the remainder of the macula (margin: 35.04±9.34; outside: 19.61±6.08; P=0.002), and CNV lesion area was positively correlated with FV (correlation coefficient =0.84; 95% CI: 0.49–0.96; P=0.001).Conclusion: Choriocapillaris flow deficits were significantly greater in wet AMD subjects than age-similar normal subjects, suggesting that choroidal hypo-perfusion likely plays a role in the pathogenesis of neovascular AMD. Recognition of choriocapillaris flow deficits in patients with AMD may facilitate earlier diagnosis and identify alternative therapeutic targets for this multifactorial disease.Keywords: flow void, AMD, OCT angiography, OCTA

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