Chorioretinal Vascular Oxygen Tension Changes in Response to Light Flicker

摘要: Oxygen consumption is a major factor in retinal metabolism. delivered to the tissue by choroidal and circulations. The supply of oxygen adapted according metabolic activity tissue. Visual stimulation light flicker increases demand inner retina.1–5 Therefore, changes PO2 chorioretinal vascular beds are likely be induced flicker, particularly circulation, which supplies retina. Light flicker–induced intravascular have been reported based on blood level–dependent signals magnetic resonance imaging, only provide combined measurement all vasculatures.6 Although optic nerve head from with phosphorescence imaging,7 arteries, veins, capillaries, choroid not investigated. Increased vessel diameter flow response under normal physiological conditions, demonstrated,8–10 reduced hemodynamic has patients hypertension, glaucoma, diabetes.11–13 According Fick principle, equals product arteriovenous content difference.14 measuring separately artery vein, coupled knowledge flow, may better means for assessing than alone. In retina, measurable efflux arterial vasculature reported.15,16 Moreover reduction gradient along caused increased demonstrated isolated small preparations.17 resulting altered must considered interpreting flicker. We previously developed technique vasculatures.18–20 purpose present study was measure vasculatures determine difference flicker. Given that influenced diffusion,15,17 variations vessels absence visual were also investigated.