Choriocapillaris Flow Deficits in Normal Chinese Imaged by Swept-Source Optical Coherence Tomographic Angiography

PURPOSE: To evaluate the ocular and systemic determinants of the choriocapillaris flow deficits percentage (CC FD%) in normal eyes. DESIGN: Observational cross-sectional study. METHODS: Healthy Chinese participants without ocular or systemic diseases underwent detailed ophthalmic evaluations, including swept-source optical coherence tomography angiography (SS-OCTA) with 6-x 6-mm macular choriocapillaris images. The CC FD% was assessed in circular regions with diameters of 1.0 and 5.0 mm, rings with 1.0-to 2.5-mm diameters, and rings with 2.5 to 5.0-mm diameters. RESULTS: The study included 830 individuals (mean +/- SD age 58.66 +/- 8.75 years). CC FD% (mean +/- SD 22.05% +/- 1.13%) was the lowest in the 2.5-to 5.0-mm ring, followed by the 1.0-to 2.5-mm ring, and highest in the 1.0-mm circle. In multivariable analysis, a higher CC FD% was associated with older age (beta = 0.16 [95% confidence interval {CI}] 0.08-0.24, P < .001), higher intraocular pressure (beta = 0.34 [95% CI 0.25-0.42], P < .001), higher serum concentrations of high-density lipoprotein cholesterol (beta = 0.24 [95% CI 0.17-0.32], P < .001), and lower image quality score (beta = -0.22 [95% CI -0.30 to -0.14], P < .001). CC FD% was also independent of axial length. CONCLUSIONS: In healthy adult Chinese individuals, a higher CC FD% was associated with older age, higher intraocular pressure, and higher high-density lipoprotein cholesterol serum concentration. These factors may influence clinical assessments of the choriocapillaris. The lack of an association between CC FD% and axial length is consistent with similar find ings for Bruch membrane thickness, macular retinal thickness, and macular retinal pigment epithelium cell density. (C) 2021 The Author(s). Published by Elsevier Inc.