Investigation of the retinal neurovascular networks through modulation of blood oxygen levels in humans

导言：人类的视网膜是由将视觉信息传递给大脑的神经元组成的。需要有效地将氧气分配到视网膜的不同层，以支持其结构和功能的完整性。视网膜和脉络膜血管确保适当的氧气分配到神经组织。组织的氧气输送很大程度上依赖于动脉的氧气浓度。在实验上，可以通过改变吸入空气中的氧气或二氧化碳浓度来改变动脉血氧水平。目的：量化视网膜神经元及其血液供应对血液中正常氧气浓度变化的反应性。科学方法：将通过闪光视网膜电波a波、b波和振荡电位以及模式诱发视网膜电波对代表主要视网膜神经元活动的生物电反应进行无创监测。视网膜中的全局和局部血流，以及离散血管和毛细血管床中的血液流动将使用专用系统进行记录。这些测量将在动脉血含氧程度发生变化时进行。预期意义：这项研究将为正常视网膜功能依赖于血液中的氧合程度提供新的见解，血液中的氧合作用在解剖上不同的视网膜层中灌流。如果我们想要了解血管在视网膜疾病中的作用，尤其是与视网膜缺血相关的疾病，这些知识是必不可少的。

Introduction: The human retina is comprised of neurons that relay visual information to the brain. An effective distribution of oxygen to the different layers of the retina is required to support their structural and functional integrity. The retinal and choroidal vasculatures insure proper oxygen distribution to neural tissue. Oxygen delivery to a tissue is strongly dependent on the arterial oxygen concentration. Experimentally, it is possible to modify the arterial oxygen level by modifying the oxygen or carbon dioxide concentrations in inspired air. Objective: To quantify changes in the responsiveness of retinal neurons and their blood supply to carefully controlled changes in the normal concentration of oxygen in blood. Scientific approach: The bio-electrical responses representing the activity of the principal retinal neurons will be monitored non-invasively through the flash electroretinogram a-wave, b-wave and oscillatory potentials, as well as the pattern evoked electroretinogram. Global and focal blood flow in the retina, and blood flow in discrete vessels and capillary beds will be recorded with dedicated systems. These measurements will be carried out during alterations in the degree of oxygenated arterial blood. Expected significance: This research will provide new insights into the dependence of normal retinal function on the degree of oxygenation in the blood perfusing the anatomically distinct retinal layers. This knowledge is essential if we are to understand the vascular role in retinal diseases, particularly those associated with retinal ischemia.