Blood flow and hemodynamics in glaucoma

项目摘要/摘要 青光眼在美国和世界范围内都是导致失明的主要原因，其特征是 视网膜神经节细胞丢失。众所周知，视神经头和视网膜内的血液流动在 青光眼。血流最初可能增加，但最终在更严重的眼睛中减少 青光眼损害。随着疾病的发展，毛细血管密度逐渐减少。还有就是 血流动力学改变的证据，在视神经内测量的脉搏波形的形状 青光眼和健康眼睛的头部是不同的。然而，目前还不知道这些变化是否会发生 因为轴突丢失降低了新陈代谢需求；或者这种变化是否有助于视网膜 神经节细胞损伤和死亡；或两者都有。这项建议将详细检查血液流动和 发生在青光眼不同阶段的血流动力学。我们将利用新技术来衡量 血管系统的不同方面，并将它们与疾病状态和进展联系起来，无论是个体还是在 组合。在目标1中，我们将测量视神经头内的血流量，当它通过 乳头周围视网膜，用于量化血流量以及测量和量化脉搏波形。这 将使我们能够测试被认为是青光眼嫌疑人的眼睛中观察到的血流差异是否 疾病过程的早期部分，可以通过诊断进行测量，和/或反映长期存在的情况 这些差异可以用来预测青光眼的易感性。在目标2中，我们还将测量系统 相同个体的脉搏波。这将使我们能够确定血流动力学上的差异 由于病理生理过程，可以通过诊断测量到的部位位于眼睛；和/或 代表了青光眼的系统性风险因素。在目标3中，我们将测量灌流血管的面积， 在视神经头和视乳头周围视网膜。这将允许我们确定流是否在 在一些毛细血管被修剪后，剩下的血管可能会造成进一步的损害。 总之，这些目标将揭示血管变化和青光眼之间关系的多个方面，以及 回答尚未解决的重大问题。总体而言，该项目将在以下方面取得重大进展 青光眼的诊断工具和机制方面的理解。

Project Summary / Abstract Glaucoma is a leading cause of blindness both in the US and worldwide, and is characterized by damage to and loss of retinal ganglion cells. It is known that blood flow within the optic nerve head and retina are altered in glaucomatous eyes. Flow may initially increase, but is eventually decreased in eyes with more severe glaucomatous damage. The capillary density gradually decreases as the disease progresses. There is also evidence of altered hemodynamics, in that the shape of the pulse waveform measured within the optic nerve head differs between glaucomatous and healthy eyes. However, it is not yet known whether these changes occur because axon loss has reduced the metabolic demand; or whether the changes contribute towards retinal ganglion cell damage and death; or both. This proposal will examine in detail the changes in blood flow and hemodynamics that occur at different stages of glaucoma. We will leverage new technologies to measure different aspect of the vasculature, and relate them to disease status and progression, both individually and in combination. In Aim 1, we will measure blood flow within the optic nerve head and as it passes through the peripapillary retina, both to quantify the amount of flow and to measure and quantify the pulse waveform. This will allow us to test whether the observed differences in flow in eyes that are considered glaucoma suspects are an early part of the disease process that could be measured diagnostically, and/or reflect longstanding differences that could be used to predict susceptibility to glaucoma. In Aim 2, we will also measure the systemic pulse waveform in the same individuals. This will allow us to determine whether differences in hemodynamics that could be measured diagnostically are localized to the eye due to pathophysiologic processes; and/or represent a systemic risk factor for glaucoma. In Aim 3, we will measure the area of perfused blood vessels, both in the optic nerve head and the peripapillary retina. This will allow us to determine whether flow is altered within the remaining vessels after some of the capillaries have been pruned, potentially causing further damage. Together, these aims will reveal multiple facets of the relation between vascular changes and glaucoma, and answer major questions that have remained unresolved. Overall, the project will provide substantial advances in both diagnostic tools and mechanistic understanding of glaucoma.