涡静脉扩张与息肉状脉络膜血管病变发病机制的相关性研究

Polypoidal choroidal vasculopathy (PCV) is a highly prevalent cause of blindness in China and other Asian countries whose prevalence between caucasians and colored races are quite different. Till now, the pathogenesis is unknown. Researches focusing on the heterogeneity of age-related macular degeneration (AMD) and PCV, the role of vascular endothelial growth factor（VEGF）and hyperpermeability of choroid membranes in the development of PCV have fell into the bottlenecks. Researches have found the characteristics of pachychoroid and fluorescent leakage in PCV which is caused by the dilatation and congestion of choroid layer. Pathology studies have also identified the dilatation and hyalinization of choroidal vein. Recently, some researchers have observed vortex vein dilatation in clinical practice. As the only draining vascular system, changes in the structure and blood flow characteristics of vortex vein can cause influence on the flow and property of choroidal vasculature. However, the mechanism underlying this phenomenon remains elusive. Vascular dilatation is caused by changes of the hemodynamics, which is influenced by the thickness and texture density of the sclera. But no studies have elucidated the relationship between sclera property and vortex dilatation, neither have the mechanism of vortex vein dilatation and PCV development. The purpose of this study is to explore the role of vortex dilatation in the development of PCV as well as factors influencing its dilation, explain the pathology of PCV in a new perspective.

息肉状脉络膜血管病变（PCV）是亚洲地区高发的严重的致盲性眼底病变，白人和有色人种患病比例不同。目前其发病机制仍不明确。多项研究着眼于AMD与PCV的异质性、VEGF及脉络膜高通透性在PCV发病过程中的作用，但尚无突破性进展。有研究发现PCV患者具有脉络膜增厚、荧光渗漏的特征，与血管扩张和充血相关。PCV的病理研究也证实脉络膜静脉血管扩张及透明样变的特征。在临床实践中，我们及其他学者观察到涡静脉扩张的现象。涡静脉作为脉络膜静脉的唯一回流血管系统，其结构与血流特性的改变会影响脉络膜血流及血管的特征，但尚无实验证实。血管扩张由血流动力学改变引起，巩膜厚度和致密度正是导致血流动力学改变的重要因素，但巩膜特性与涡静脉扩张之间的关系尚未明确。目前涡静脉扩张与PCV发生的内在相关性及具体机制尚无研究。本研究旨在探索涡静脉扩张在PCV发生中的作用，阐明涡静脉扩张的影响因素，从新角度阐释PCV的发病机制。

息肉状脉络膜血管病变（Polypoidal choroidal vasculopathy, PCV）是一种好发于亚洲人群的致盲性眼底疾病。其主要的特征为眼底异常脉络膜分支血管网及其末端血管呈息肉样扩张，常伴有反复眼底出血和积液。目前，PCV的发病机制尚不清楚。涡静脉扩张伴脉络膜增厚是PCV的临床特征之一。.本研究通过建立涡静脉血流障碍动物模型，分析涡静脉血流障碍所致的脉络膜血流动力学变化、结构变化及其对眼内免疫-炎症环境的影响。探究涡静脉血流障碍在PCV发病中的可能机制。同时收集就诊于北京协和医院眼科的PCV患者临床资料，对患者进行长期随访。结合患者多种眼底影像学检查，对PCV患者临床表现进行分析，提出诊断PCV的无创多模式诊断标准及多光谱视网膜成像（Multispectral retinal imaging，MSI）特征，并对多模式影像检查及多光谱视网膜成像对PCV诊断的敏感性与特异性进行进一步分析。同时通过对PCV患者进行长期随访观察，分析抗血管内皮生长因子（antivascular endothelial growth factor，anti-VEGF）单药治疗和光动力联合抗VEGF治疗PCV的长期视力预后情况。.结果表明涡静脉血流受阻可引起脉络膜血管结构的改变，提示涡静脉血流障碍可能是引起PCV的发病基础之一。同时，本研究提出的基于多模式影像检查的PCV诊断标准具有很高的特异性和敏感性，对于临床诊断PCV具有重要的参考意义。基于PCV多光谱视网膜成像的研究结果提示PCV在这一影像学检查中具有多个敏感指标，为今后无创诊断PCV提供了新的参考指标。最后，对两种分型PCV的长期治疗结果表明2型PCV的视力预后显著优于1型PCV，抗VEGF单药治疗和起始联合治疗优于延迟联合治疗。与视力预后相关的影像学生物标志物具有重要的临床意义。