Quantitative Assessment of Foveal Avascular Zone in Patients with Early and Intermediate Nonexudative Age-Related Macular Degeneration Using Optical Coherence Tomography-Angiography

Abstract

Optical coherence tomography-angiography (OCT-A) is a relatively new non-invasive imaging technique which provides three-dimensional visualization of the retinal and choroidal microvasculature. Recently, OCT-A is widely used in the diagnosis of age-related macular degeneration (AMD). Purpose: To compare 3 quantitative indexes of foveal avascular zone (FAZ)—area (A), perimeter (Pm), and circularity (C) in patients with early and intermediate nonexudative AMD and healthy subjects using OCT-A. Methods: Eighty-nine patients with nonexudative AMD (n = 89 eyes) were enrolled in the study. They were compared with sex- and age-matched control group of 66 healthy subjects (n = 66 eyes). The patients with nonexudative AMD were divided into 2 subgroups—early AMD (n = 42 eyes) and intermediate AMD (n = 47 eyes). All participants underwent OCT-A (3 × 3 mm scans, Cirrus HD-OCT, Angioplex, Carl Zeiss Meditec, Dublin, CA). Results: There was no statistically significant difference in all 3 assessed indexes between the early AMD subgroup and the control group (A ? P = 0.139; Pm ? P = 0.230; and C ? P = 0.191). There was also no statistically significant difference in all 3 assessed indexes between the intermediate AMD subgroup and the control group (A ? P = 0.106, Pm ? P = 0.124, and C ? P = 0.102, respectively). Conclusions: According to our results from the assessment of FAZ in patients with early and intermediate AMD, we hypothesize that macular perfusion remains fairly unchanged in the nonexudative stages of the disease. OCT-A is a reliable technique for visualizing and quantifying FAZ in patients with nonexudative AMD.