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

人类的视网膜是由神经元组成的，它们将视觉信息传递给大脑。有效地将氧气分配到视网膜的不同层是支持其结构和功能完整性所必需的。视网膜和脉络膜血管确保神经组织的适当氧气分配。氧输送到组织强烈依赖于动脉血氧浓度。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供对精心控制的正常血氧浓度变化的反应性变化。科学方法：代表视网膜主要神经元活动的生物电反应将通过闪现视网膜电图a波、b波和振荡电位以及模式诱发视网膜电图进行无创监测。视网膜的整体和局部血流，以及离散血管和毛细血管床的血流将用专用系统记录。这些测量将在动脉血氧合度变化时进行。预期意义：本研究将为正常视网膜功能对灌注在解剖上不同的视网膜层的血液氧合程度的依赖提供新的见解。如果我们要了解血管在视网膜疾病中的作用，特别是那些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.