原发性闭角青光眼(PACG)是主要不可逆性致盲眼病。常见的非瞳孔阻滞型原发性房角关闭疑似者(NPB-PACS)行预防性虹膜周切术后，房角仍继续变狭窄，甚至恶化为PACG。其自然病程，危险因素及发病机制尚未明确。我们在“荔湾眼病研究”及“中山闭角青光眼预防”研究中，发现虹膜体积变化速率可能是其中关键的危险因素，提出“虹膜是弹性海绵”假设，认为虹膜舒缩功能与基质层结构的异常是NBP-PACG发生发展的基础，预期虹膜体积变化速率小者发生PACG危险性大。拟募集NBP-PACS患者及对照组，研究在不同种类与强度或浓度的光、植物神经受体激动剂与抑制剂作用下，虹膜及瞳孔各参数的变化速率和比例，分析其中的量-效关系及其纵向改变规律，通过大样本的队列研究，揭示这些规律与NPB-PACS的自然病程中发生眼压升高、PAS形成等终点指标之间有无因果关联及关联大小，在神经-效应器-基质层特征水平阐明其发病机制。

Primary Angle Closure Glaucoma (PACG) is the leading cause of irreversible blindness worldwide. In a dominant subtype,the Non-Pupillary Block type Angle Closure Suspect (NPB-PACS), the angle remains occludable and may develop to primary angle closure or even PACG after the pupillary block is released by laser peripheral iridotomy(LPI). Its nature course, mechanism and associated risks factors are still unknown because of the lacking of prospective study about them. In the “Liwan eye study” and the “Zhongshan Angle Closure Prevention Trial” ,we found that the shift speed, as well as the proportion, is the key risk factor, suggesting that the abnormality of iris muscle function and matrix strcture are fundamental for NBP-PACG development. We hyothesize that “The iris is an elastic sponge” to guide our cohort study, suggesting that those who are with smaller speeed of iris volume change under certain stimus are more likely to reach endpoinds as IOP elevation and PAS formation. We plan to recruit NBP-PACS voluntees and control to take part in the cohort study.We will study the dose-effect relations of the iris structure shifting speed and proportion under different conditions, including various frequence and strength of light, different concentration of sympathetic and parasympathetic antagonist or stimulant.By studying the effect with those from UBM,AS-OCT,SD-OCT measurement,statistical annalysis will unveil the mechanism of NPM-PACS in order to provide evidence in the prevention and treatment of the disease.