Investigation of Factors Associated with Retinal Oxidative Stress and Inflammation that affect the Foveal Avascular Zone in Healthy Eyes: An Optical Coherence Tomography Angiography Study

Abstract

Purpose The size and shape of the foveal avascular zone (FAZ) can change due to retinal diseases associated with oxidative stress and inflammation, such as diabetic retinopathy, glaucoma, hypertensive retinopathy and macular degeneration. Macular pigment (MP), a powerful retinal antioxidant, may confer protection. This study aims to assess the relationship, if any, between factors that may affect the superficial FAZ (i.e. blood pressure (BP), vessel density, perfusion, overweight/obesity), and possible links with MP optical density (MPOD), in young, healthy subjects. Methods One hundred and fifty-four subjects, aged 18 to 35 years, were recruited. The superficial FAZ area, foveal vascularity and central macular thickness (CMT) were assessed using the Cirrus 5000. Health parameters including, BP, body mass index (BMI), trunk fat % and MPOD were analyzed, to determine possible associations with the FAZ. Results Mean FAZ area was 0.23 ± 0.08mm2. FAZ area was positively correlated with BMI (Pearson’s r = 0.189, p = 0.03) and significantly larger in participants with lower MPOD, on bivariate analysis (p = 0.04). Significant correlates of FAZ area in the multivariate model included age, sex, BP, vessel perfusion central, CMT and trunk fat %, which collectively contributed 65.2% of the overall variability. Conclusion These findings suggest that reduced vessel perfusion, thinner CMT, higher trunk fat % and low MPOD are plausible predictors of a larger FAZ area, in healthy eyes. Non-invasive OCTA testing, in association with these predictors, may aid in the early detection and monitoring of retinal diseases associated with oxidative stress and inflammation.