Systemic and Ocular Determinants of Macular Vessel Metrics in Optical Coherence Tomography Angiography (OCTA) 6x6 Scans in Healthy African Americans

Abstract

Purpose : To determine the relationship of various systemic and ocular characteristics with macular vessel density in the African American Eye Disease Study.

Methods : Participants consisted of African Americans 40 years of age and older residing in Inglewood, CA. They underwent 6x6-mm macula eye scans using spectral-domain optical coherence tomography angiography (OCTA; CIRRUS 5000 HD-OCT with AngioPlex; ZEISS, Dublin, CA, USA), a clinical examination, and a clinical questionnaire. Participants with glaucoma, severe non-proliferative diabetic retinopathy, proliferative diabetic retinopathy, and macular edema were excluded. A custom MATLAB based software was used to quantify vessel area density (VAD), vessel skeleton density (VSD), and flux in the superficial retinal layer (SRL) of the macula. Inter-eye correlation was controlled for using generalized estimating equations (GEE). Using SAS, a multivariate regression analysis was performed to determine systemic and ocular determinants of macular vessel metrics using stepwise selection. Candidate variables included: age, gender, body mass index, history of smoking, history of diabetes, diabetes duration, history of stroke or brain hemorrhage (SB), systolic blood pressure (BP), diastolic blood pressure (DBP), pulse pressure (PP), mean arterial pressure (MAP), central subfield thickness (CSFT), visual field mean deviation (MD), intraocular pressure (IOP), axial length (AL), mean ocular perfusion pressure (MOPP), and signal strength (SS).

Results : A total of 2221 OCTA imaged eyes from 1472 participants remained after excluding eyes for either poor image quality or the presence of an ocular disease. As demonstrated in the table, after controlling for signal strength and age, longer axial length and reduced central subfield thickness were independently associated with reduced VAD, VSD and Flux. Male gender and decreased diastolic blood pressure were also independently associated with reduced flux.

Conclusions : When assessing OCTA images in a clinical setting, it is important to consider the effect axial length, central subfield thickness, gender, and diastolic blood pressure may have on the macular microcirculation.

This is a 2021 ARVO Annual Meeting abstract.