Impacts of Camellia sinensis fermentation end-product (black tea) on retinal microvasculature: an updated OCTA analysis

Abstract

BACKGROUND Tea, second only to water, is one of the most regularly consumed drinks in the world. Its potentially beneficial effects on general health may be enormously important. Optical coherence tomography angiography (OCTA) now allows clinicians to examine the acute retinal morphological changes caused by black tea consumption. The purpose of this study was to investigate the acute impacts of a Camellia sinensis fermentation end-product (black tea) on retinal microvasculature in healthy individuals using OCTA. RESULTS In this study, 60 healthy people were divided into two groups: group 1 (n = 30) received black tea (2 mg/250 mL of water) and group 2 (n = 30) received only 250 mL of water. Following consumption, AngioVue Analytics software automatically analyzed the foveal, parafoveal, perifoveal macular superficial and deep vascular plexus densities, foveal avascular zone (FAZ) area, FAZ perimeter and foveal vessel density in a 300 μm wide region around the FAZ (FD-300). Male-to-female ratios were 19:11 and 15:15 in groups 1 and 2, respectively (P = 0.217). Mean age was 33.27 ± 7.92 years in group 1 and 31.00 ± 7.30 years in group 2 (P = 0.254). Changes in foveal, perifoveal and parafoveal macular vessel density between groups 1 and 2 were not statistically significant. In addition, no significant differences regarding FAZ, FAZ perimeter and FD-300 were observed. CONCLUSION There were no acute effects of black tea on macular microcirculation in healthy individuals. The authors, however, believe that this study could serve as a model for future research on the relationship between regular tea consumption and general ocular physiology. © 2021 Society of Chemical Industry.