Cellular Physiology of the Aqueous Outflow Pathway

原发性开角型青光眼(POAG)是世界范围内致盲的主要原因。一个主要的风险因素是 POAG的发生和发展是由于眼压升高引起的眼压升高。 水的流出阻力。大多数这种阻力被认为是在邻近的连接词中产生的 组织(JCT)，并受Schlemm管内壁内皮(SC)及其巨大空泡和 毛孔。然而，调节流出阻力的确切机制仍不清楚。我们的长期目标是 为了了解调节正常眼房水流出阻力的机制，以及这种阻力是如何 在POAG中有所增加。在我们上一次融资期间，我们开发了全球成像，这是一种可以可视化的技术 眼球周围的流出模式，并区分眼球内的高、低或无血流区域 小梁网(TM)、SC和远端巩膜上静脉。在这三个部分，我们发现有房水流出 要有节段性。我们将流动活跃的区域定义为有效过滤面积(EFA)。我们发现了相反的结果 EFA与眼压和流出阻力的关系。我们还发现，全民教育和流出设施 接受Rho-Kinase抑制剂、基因修饰和最低限度降眼压方法治疗的患者眼压增加 使用TM旁路设备的侵入性青光眼手术(MIG)。基于这些结果，我们这个项目的目标是 确定哪些机制有助于全民教育的监管。我们将区分形态特征 高、低和非流动区，并确定我们是否可以通过转换 无流量/低流量区域到高流量区域。为了实现我们的目标，我们开发了一种3D电子显微镜 一种可靠地提供巨大空泡、毛孔和细胞的体积和几何定量的方法 SC内墙与其底层JCT之间的连接。我们将测试我们的假设，细胞 内壁内皮上的连接调节巨型空泡和孔洞的形成，从而调节EFA。 我们还将率先开发一种具有实时成像的新型3D细胞培养设备，以仔细观察细胞骨架的变化 Rho-Kinase抑制剂处理后的结构和巨大空泡的形成。重要的是，我们加强了 将其与荧光素血管造影相结合的全局成像技术，以区分前和后的血流模式 在降眼压治疗后。这为识别新改建的高流量区域提供了机会 因为使用了Rho-Kinase抑制剂。这些创新的方法使我们能够解决临床上的争论，即 MIGS装置应放置在高流量区或非流量区，以优化术后眼压的降低。我们的特定 目的是：1.区分高流量区和低流量区与非高流量区SC内壁的结构变化 正常眼和POAG眼的流动区；2.测定Rho-Kinase抑制剂对巨大空泡和孔洞的影响 地层；3.确定放置TM旁路的最佳位置(高、低与高相邻或无流动区) 支架有效提高全民教育水平。这项研究的结果将增进我们对全民教育和 流出阻力被调节，并有可能改进目前临床上降低POAG眼压的方法。

Primary open-angle glaucoma (POAG) is a leading cause of blindness worldwide. A primary risk factor for the development and progression of POAG is elevation of intraocular pressure (IOP), caused by an increase in aqueous outflow resistance. Most of this resistance is believed to be generated in the juxtacanalicular connective tissue (JCT) and modulated by the inner wall endothelium of Schlemm’s canal (SC), and its giant vacuoles and pores. However, the exact mechanisms that regulate outflow resistance remain unclear. Our long-term goal is to understand the mechanisms that regulate aqueous outflow resistance in normal eyes and how this resistance is increased in POAG. In our last funding period, we developed global imaging, a technique that can visualize the outflow pattern around the circumference of the eye and distinguish areas of high, low, or non-flow in the trabecular meshwork (TM), SC, and the distal episcleral veins. In these three parts, we found aqueous outflow to be segmental. We defined the area with active flow as the effective filtration area (EFA). We found inverse relationships between EFA and both IOP and outflow resistance. We also found that EFA and outflow facility increased in eyes treated with methods of lowering IOP: Rho-kinase inhibitors, gene modification, and minimally invasive glaucoma surgery (MIGS) using TM bypass devices. Based on these results, our goal of this project is to determine what mechanisms contribute to the regulation of EFA. We will distinguish morphological features of high, low, and non-flow areas, and determine whether we can increase EFA to lower IOP by converting non/low-flow areas to high-flow areas. To achieve our objectives, we developed a 3D electron microscopy method to reliably provide volumetric and geometric quantitation of giant vacuoles, pores, and cellular connections between the SC inner wall and its underlying JCT. We will test our hypothesis that cellular connections in the inner wall endothelium modulate giant vacuole and pore formation, thereby regulating EFA. We will also pioneer a novel 3D cell culture device with real-time imaging to scrutinize changes in cytoskeletal structure and giant vacuole formation after Rho-kinase inhibitor treatment. Importantly, we have enhanced the global imaging technique by combining it with fluorescein angiography to distinguish flow patterns before and after an IOP-reducing treatment. This offers the opportunity to identify newly converted high-flow areas arising from use of Rho-kinase inhibitors. These innovative methods allow us to address the clinical debate as to whether MIGS devices should be placed in high or non-flow areas to optimize post-operative IOP reduction. Our Specific Aims are: 1. To differentiate structural changes along inner wall of SC in high-flow areas compared to low/non- flow areas of normal and POAG eyes; 2. To determine effect of Rho-kinase inhibitors on giant vacuoles and pore formation; 3. To determine the best location (high, low adjacent to high, or non-flow area) to place a TM bypass stent to effectively increase EFA. The results of this study will advance our understanding of how EFA and outflow resistance are regulated, and potentially improve current clinical methods of IOP reduction in POAG.