COLOR DOPPLER IMAGING OF THE RETINA AND CHOROID

视网膜和脉络膜血流调节的缺陷是糖尿病视网膜病变、青光眼和其他威胁视力的疾病的部分病因，但对流向视网膜的血液的物理和生理控制知之甚少，至少部分原因是由于目前测量血流量的方法的局限性。本研究的目的是定量研究脉络膜和视网膜循环中血流和血流动力学的控制及其与视网膜疾病的关系。假设视网膜和脉络膜循环中的血流是不均匀的，血流的不均质性增加可能是视网膜和脉络膜循环功能障碍的早期指标。作为这项工作的一部分，将对脉络膜和视网膜循环中的组织灌注量进行同步、连续和定量的测量，以研究视网膜和脉络膜循环如何响应生理条件。之前关于血管系统在健康和疾病中的作用的研究受到技术限制的阻碍。在这个项目中，彩色多普勒光学相干断层成像(CDOCT)，一种新的非侵入性成像技术，将被用于测量服务于视网膜的循环中的血流动力学参数。具体目标将首先涉及血流的仪器和量化，然后使用体内与激光多普勒血流计的比较来验证结果，激光多普勒血流计是目前最常用的评估血流灌注的方法。然后，该方法将被用于动物实验，以确定灌流压力和血气对视网膜和脉络膜循环中血流和局部红细胞压积的区域分布的影响，以及在有和没有神经节阻滞和其他对这两个循环起不同作用的动作的情况下。

Defects in the regulation of retinal and choroidal flow are part of the etiology of diabetic retinopathy, glaucoma, and other vision-threatening disorders, yet the physics and physiology controlling of blood flow to the retina is poorly understood, at least in part because of the limitations of current methods of measuring blood flow. The goal of this research is to quantitatively study the control of flow and the hemodynamics in the choroidal and retinal circulations and their relationships to retinal disease. The hypothesis is that blood flow in the retinal and choroidal circulations is not homogeneous and that increased heterogeneity in blood flow may be an early indicator of dysfunction of the retinal and choroidal circulations. As part of this work simultaneous, continuous and quantitative measurements of tissue perfusion in the choroidal and retinal circulations will be made to allow study of how the retina and choroidal circulations interact in response to physiological conditions. Previous investigations of the role of the vasculature in health and disease have been hampered by the limits of technology. In this project Color Doppler Optical Coherence Tomography (CDOCT), a novel non-invasive imaging technology, will be adapted to measure hemodynamic parameters in the circulations that serve the retina. The specific aims will first address the instrumentation and quantification of blood flow and then validate the results using in-vivo comparison to Laser Doppler Flowmetery, the most commonly used current method of assessing perfusion. The method will then be used in animal experiments to determine the effects of perfusion pressure and blood gasses on the regional distribution of blood flow and local hematocrit in the retinal and choroidal circulations, with and without ganglionic blockade and other maneuvers which act differently on the two circulations.