The effects of exercise on peripapillary retinal oxygenation

Abstract

AbstractPurpose Blood flow to the retina is maintained by central retinal vessels that exhibit autoregulatory capacity. Physical activity has been demonstrated to have acute, transitory, effects on ocular haemodynamic factors including intraocular pressure and blood pressure. What remains unclear is how the oxygen saturation of retinal blood vessels is affected by prior levels of physical activity. The aim of the study is to assess the impact of physical activity on peripapillary retinal vessel oxygenation.Methods Eight eyes from eight healthy volunteers were assessed in the study. Peripapillary retinal vessel oxygenation (dual‐wavelength fundus images; 548nm and 610nm), blood pressure (automated sphygmamometer) and intraocular pressure (non‐contact tonometer) was assessed before, immediately after, and 15 minutes following a period of aerobic exercise (Master’s two‐step stress test).Results Average peripapillary arterial oxygenation increased from 95.01% ± 9.62% (mean ± standard deviation) before exercise to 97.57% ± 9.90% (paired t‐test, p=0.028) immediately following exercise, and 96.67% ± 10.54% (p=0.163) at 15 minutes following exercise. Average peripapillary venous oxygenation increased from 57.95% ± 17.29% before exercise to 64.06% ± 21.13% (p=0.006) following exercise, and 61.40% ± 17.03% (p=0.055) at 15 minutes.Conclusion This pilot study demonstrates that modest levels of physical activity can induce significant changes in blood oxygenation across arteries, veins, and the arteriovenous difference. Our results appear to suggest that subjects should be physically rested for at least fifteen minutes before resting retinal oxygenation is assessed.