Comparison of foveal avascular zone and retinal vascular density in healthy Chinese and Caucasian adults

Purpose The aim of this study was to measure and compare the retinal vascular parameters and foveal avascular zone (FAZ) in Chinese and Caucasian populations by using optical coherence tomography angiography (OCT-A). Methods Fifty-one eyes of Han Chinese and 43 eyes of Caucasians were retrospectively included in our study. The measurements were acquired using Zeiss Cirrus 5000, with the same software version 10 in Poland and China. Results The size of the FAZ was 0.33 +/- 0.012 and 0.28 +/- 0.014 mm(2) (p = 0.0289) and the diameter was 2.43 +/- 0.06 and 2.18 +/- 0.07 mm (p = 0.0057) for Chinese and Caucasian populations, respectively. However, no differences were observed in circularities between the populations. The full Early Treatment of Diabetic Retinopathy Study (ETDRS) vessel length density was significantly different for Chinese (17.05 +/- 0.24 mm/mm(2)) and Caucasian (16.08 +/- 0.43 mm/mm(2)) populations. In addition, the outer ETDRS vessel length density was significantly different for Chinese (16.43 +/- 0.42 mm/mm(2)) and Caucasian (17.47 +/- 0.24 mm/mm(2)) populations, but the central 7.33 +/- 1.68 versus 9.32 +/- 1.54 mm/mm(2) for the Caucasian and Chinese and inner 16.14 +/- 0.52 for Caucasian and 16.93 +/- 0.27 mm/mm(2) for Chinese subjects density was not. A significant yet weak positive correlation between FAZ and vessel density was observed (r = 0.216). Furthermore, no significant intersexual differences were observed in study parameters. Conclusion The Chinese population had larger FAZ with higher vessel length density in the superficial layers of the retina than the Caucasian population.