Retinal Vascular Oxygen Saturation in a Sample of Chinese Myopic Adults.

Purpose: The aim of the study was to investigate the normal retinal vascular oxygen saturation and to elucidate the factors affecting it or associated with it in a Chinese population. Methods: This was a population-based observational cross-sectional study. Chinese myopic adults aged 18 to 45 years old were enrolled. Spherical equivalent (SE) and ocular biometry, including average keratometry (K), central corneal thickness, intraocular pressure, and axial length, were measured. The retinal arteriolar (SaO2) and venous (SvO2) oxygen saturation were measured after pupil dilatation. Results: A total of 1373 participants were enrolled, and the mean age, SE, SaO2, and SvO2, were 26.31 ± 6.93 years, -6.40 ± 3.12 D, 93.47% ± 1.58%, and 63.08% ± 4.46%, respectively. In the multivariate analysis, SaO2, SvO2, and retinal arteriovenous oxygen saturation difference (AVD) were significantly correlated with age (β = 0.077, P = 0.006 for SaO2 and β = 0.080, P = 0.006 for AVD) and SE (β = 0.220, P < 0.001 for SaO2; β = 0.131, P < 0.001 for SvO2; and β = -0.050, P = 0.048 for AVD, respectively). Higher SaO2 was associated with larger K values (β = 0.094, P = 0.001). Conclusions: SaO2 increased with older age, lower myopia, and larger K values, older age was associated with higher SaO2 and AVD, and SvO2 decreased with the deepening of myopia. Our present study provided normative values for healthy Chinese myopic adults with different myopic refractive errors.