原发性闭角型青光眼发病机制的研究进展

原发性闭角型青光眼(PACG)是导致失明的常见原因，房角关闭是PACG的一个基本病理过程。随着眼科设备的发展，对PACG的发病机制有了更深入的了解。除了传统的瞳孔阻滞、高褶虹膜机制，研究发现其发病原因不仅与异常眼球解剖结构相关，还与眼部动态变化因素、遗传因素和心理生理应激因素等有较为密切的关系。本文结合文献报道对PACG的发病机制和危险因素进行归纳总结，以期为临床工作提供指导作用，为青光眼的早期诊断和治疗方案的制定提供有益的理论支撑。     

虹膜在原发性闭角型青光眼发病机制中的研究进展

原发性闭角型青光眼(primary angle-closure glaucoma, PACG)是不可逆性致盲性眼病,其视神经损害是由于房角关闭导致眼压升高造成的。PACG的基本病理过程是房角关闭,而周边虹膜组织机械性阻塞小梁网或者与小梁网产生黏连是导致房角关闭的重要原因。随着眼前段活体测量技术的发展,对于虹膜相关危险因素与PACG的发生和发展有了进一步的认识。本文对PACG发生的虹膜相关机制进行了归纳总结,为其预防和诊疗提供了新思路。     

虹膜特性在房角关闭中作用的研究进展

青光眼是一类以视神经凹陷性萎缩和视野缺损为共同特征的视神经退行性病变。在亚洲原发性闭角型青光眼(PACG)的患病人数逐年递增并严重影响患者的生活质量, 房角关闭是PACG的致病基础, 尽早识别房角关闭的风险因素并减缓其进展对于PACG预后具有至关重要的作用。随着近年对虹膜的研究不断深入, 发现虹膜容积变化亦是PACG发生的重要动态风险因素。本文汇总国内外最新研究结果, 分别从虹膜的组织学、生物特性、表面特征、血管结构及基因组学等方面进行总结, 详细分析虹膜特性在房角关闭中的作用, 以期为临床诊疗和研究工作提供参考。     

激光虹膜成形术治疗非瞳孔阻滞型房角关闭

目的观察激光周边虹膜成形术对非瞳孔阻滞型房角关闭的治疗效果。方法病例系列研究:对17例(31只眼)非瞳孔阻滞型原发性闭角型青光眼(PACG)于周边虹膜切除术后进行激光周边虹膜成形术治疗,采用超声生物显微镜于术前和术后1周测量房角宽度和虹膜厚度,并应用前房角镜观察房角粘连情况。随访3～17月,平均8月。结果激光周边虹膜成形术后一周,房角开放距离(AOD)较术前明显增大(P<0.01),小梁虹膜夹角(TIA)增宽、部分患者周边虹膜前粘连(PAS)减少、周边虹膜变薄,随诊期间未发现高眼压及前房角进行性粘连。结论激光虹膜成形术可以明显加深非瞳孔阻滞型PACG的周边前房,增宽房角入口,从而预防房角粘连的进一步进展。     

原发性前房角关闭能被筛查吗？

周边虹膜阻塞小梁网是原发性闭角型青光眼（PACG）房水外流障碍的原因。在多数病例,这种前房角关闭过程出现在眼压升高及青光眼性视神经病变之前。既往的研究表明,如果在窄房角眼实施有效的预防性治疗如激光周边虹膜切开术（LPI）,可防止发生青光眼性视神经病变,而不必进一步治疗。因此,在周边虹膜前粘连（PAS）形成或眼压升高之前筛查前房角关闭是有价值的,尤其是对早期患者譬如具有窄房角者,即可疑原发性前房角关闭（PACS）者。     

氩激光虹膜成形术治疗多发性睫状体囊肿导致的高褶虹膜结构[英]／Crowston JG…／／Am J Ophthalmol．

高褶虹膜综合征是导致房角关闭的原因之一，表现为特征性的周边虹膜凸起，行周边虹膜切除亦不能缓解。虹膜根部及睫状体的囊肿也可引起类似的高褶虹膜结构及继发性闭角型青光眼。作者报道一例43岁男性患者，左眼疼痛伴视力减退24小时。检查左眼视力为20／200，裂隙灯检查提示急性闭角型青光眼体征。眼压58mmHg，前房角镜检查房角关闭。对侧眼裸眼视力20／20，房角存在关闭可能，     

虹膜脉络膜在闭角型青光眼中的作用机制研究进展

PACG是一种常见的不可逆的致盲性疾病。以往认为其特征性房角关闭的危险因素包括浅前房、短眼轴、厚晶状体等静态解剖因素,还包括虹膜动态变化,脉络膜膨胀等房角动态因素。随着各项眼科影像学技术的发展,人们能更细致地观察到眼球各解剖结构在房角关闭中的作用。其中,虹膜及脉络膜在闭角型青光眼中起到的作用已越来越为人们所重视,借助眼前节OCT（AS-OCT）等各种眼科影像学技术,我们对前房角关闭的机制有了新的认识,可进一步深入阐明虹膜脉络膜与房角关闭之间的联系,为闭角型青光眼早期诊断和个体化治疗做出指导。     

预测及筛查原发性闭角型青光眼高危人群的研究进展

危险窄房角者若能在急性房角关闭及周边虹膜前粘连形成之前筛查出高度可疑前房角关闭者,可早期阻断发病环节,对防止演变成原发性闭角型青光眼（primaryangleclosureglaucoma,PACG）具有重要意义。PACG的预测及筛查方法中,前房角镜检查、超声生物显微镜、眼前段相干光断层扫描、Scheimpflug照相技术有各自的优缺点。预测及筛查PACG涉及众多的眼球生物学参数测量,最新的研究进展涉及静态参数与动态参数。前者包括前房深度、宽度、体积、面积,房角开放程度参数,虹膜厚度、体积、曲率,晶状体厚度、相对位置、拱高等;后者包括虹膜容积变化测量及葡萄膜渗漏检查等。     

原发性闭角型青光眼发病机制的研究进展

原发性闭角型青光眼是主要的不可逆致肓眼病.随着影像技术在眼科应用的进展,人们对前房角关闭机制的了解越来越深入.目前认为它的发病机制主要包括瞳孔阻滞机制、高褶虹膜机制、晶状体诱发性机制、恶性青光眼、脉络膜膨胀机制及混合机制.因各种发病机制的影响因素和治疗原则有所差异,要求针对前房角关闭患者的病因治疗不能千篇一律.动态生理性改变将是前房角关闭的重要研究方向之一.     

原发性闭角型青光眼发病机制的研究进展

原发性闭角型青光眼是主要的不可逆致肓眼病.随着影像技术在眼科应用的进展,人们对前房角关闭机制的了解越来越深入.目前认为它的发病机制主要包括瞳孔阻滞机制、高褶虹膜机制、晶状体诱发性机制、恶性青光眼、脉络膜膨胀机制及混合机制.因各种发病机制的影响因素和治疗原则有所差异,要求针对前房角关闭患者的病因治疗不能千篇一律.动态生理性改变将是前房角关闭的重要研究方向之一.     

Primary angle closure glaucoma: What we know and what we don’t know

Primary angle-closure glaucoma (PACG) is a common cause of blindness. Angle closure is a fundamental pathologic process in PAGC. With the development of imaging devices for the anterior segment of the eye, a better understanding of the pathogenesis of angle closure has been reached. Aside from pupillary block and plateau iris, multiple-mechanisms are more common contributors for closure of the angle such as choroidal thickness and uveal expansion, which may be responsible for the presenting features of PACG. Recent Genome Wide Association Studies identified several new PACG loci and genes, which may shed light on the molecular mechanisms of PACG. The current classification systems of PACG remain controversial. Focusing the anterior chamber angle is a principal management strategy for PACG. Treatments to open the angle or halt the angle closure process such as laser peripheral iridotomy and/or iridoplasty, as well as cataract extraction, are proving their effectiveness. PACG may be preventable in the early stages if future research can identify which kind of angles and/or persons are more likely to benefit from prophylactic treatment. New treatment strategies like adjusting the psychological status and balancing the sympathetic-parasympathetic nerve activity, and innovative medicines are needed to improve the prognosis of PACG.In this review, we intend to describe current understanding and unknown aspects of PACG, and to share the clinical experience and viewpoints of the authors.     

Prevalence of plateau iris configuration in primary angle closure glaucoma using ultrasound biomicroscopy in the Indian population

Purpose:

To report the prevalence of plateau iris in patients with primary angle closure glaucoma (PACG), in North India.

Materials and Methods:

The patients with PACG, attending the glaucoma services at a tertiary care center in North India were included in the study. All patients had undergone Nd-YAG laser peripheral iridotomy at least four weeks prior to inclusion in the study. Four weeks prior to inclusion in the study, none of the patients had used pilocarpine. Ultrasound Biomicroscopy (UBM) images were qualitatively evaluated and plateau iris configuration was defined in an eye if the following criteria were fulfilled in two or more quadrants: anteriorly directed ciliary process supporting the peripheral iris, steep rise of iris root from its point of insertion followed by a downward angulation from the corneoscleral wall, absent ciliary sulcus, and iridotrabecular contact in the same quadrant.

Results:

One hundred and one eyes were included in the study. There were 63 (62.4%) females and 38 (37.6%) males. The mean age of the patients was 57.8 ± 9.5 years (range: 42 to 78 years). The mean axial length in the study population was 22.2 ± 1.1 mm. The mean spherical equivalent refraction was 0.06 ± 1.12 D. The mean intraocular pressure was 18.5 ± 4.7 mmHg (range: 12 – 24 mmHg). Twenty-nine (28.7%) subjects were diagnosed with plateau iris on the basis of above-defined criteria. Of the 29 eyes, 18 (62.1%) subjects had plateau iris in two quadrants, nine (31.03%) in three quadrants, and two (6.8%) had this configuration in all the four quadrants.

Conclusions:

Approximately 30% of the eyes with PACG had plateau iris on UBM. Plateau iris was very often the cause for residual angle closure following laser peripheral iridotomy in Indian eyes with PACG.     

原发性闭角型青光眼房角关闭机制的研究进展

本文总结了原发性房角关闭与原发性闭角型青光眼的概念,综述了原发性闭角型青光眼房角关闭机制分为单纯性瞳孔阻滞型、单纯性非瞳孔阻滞型和多种机制共存型,并对导致房角关闭的相关因素做了分析。     

中国人闭角型青光眼房角关闭机制的研究

目的 对中国人原发性闭角型眼光眼（闭青）房角关闭机制进行研究,为按发病机制分类提供依据。方法采用超声生物显微镜和诊断性的治疗方法对１２６例（１２６只眼）原发性闭青的房角及房角相关解剖结构进行活体、实时、定性及半定量观察分析。结果根据ＵＢＭ房角及房我有相关解剖结构的观察,可将原发性闭青房锄头 闭机制分为单纯性瞳孔阻滞型（４８例,４８只眼,占３８．１％）,单纯性非瞳孔阻滞（９例,９只眼,占７．１％）,     

原发性闭角型青光眼患者与可疑原发性房角关闭患者虹膜睫状体构型特征的比较分析

目的 比较原发性闭角型青光眼（PACG）患者与可疑原发性房角关闭（PACS）患者的房角生物学特征。设计 回顾性比较性病例系列。研究对象 2019年10月至2021年3月同济医院58例PACG及PACS患者。方法 回顾患者病例资料及超声生物显微镜（UBM）图像,测量其房角生物学参数,进行定量及定性分析。主要指标 中央前房深度（ACD）、500 μm房角开放距离（AOD500）、500 μm小梁虹膜夹角（TIA500）、500 μm小梁睫状突距离（TCPD500）、500 μm小梁睫状体夹角（TCA500）、虹膜根部厚度（IT500）、睫状突长度（CPL）、睫状体厚度（CBT）。结果 与PACS组（n=25）相比,PACG组（n=33）患者最佳矫正视力（BCVA）更低（0.4±0.35、0.2±0.17）,基线眼压更高（21.17±6.09、15.57±3.57 mmHg）,眼轴更短（22.17±1.22、22.74±0.88 mm）,ACD更浅（1.77±0.27、1.94±0.25 mm）,AOD500、TIA500、TCPD500、TCA500更小（0.04±0.04、0.10±0.05 mm;3.90±4.58、11.07±4.77°;0.51±0.10、0.58±0.10 mm;60.55±13.26、71.54±12.58°）,CPL更长（1.43±0.26、1.28±0.15 mm）。虹膜插入点位于睫状体基底部的比例（54.5%、20.0%）及睫状体前旋的比例（68.0%、39.4%）PACG组较PACS组更大（P均<0.05）。而IT500、CBT、虹膜成角和虹膜凸度在两组间未见差异。结论 PACG眼较PACS眼具有更短的眼轴和更浅的前房,长而前旋的睫状体构型更明显,虹膜插入点位于基底部的比例更高。（眼科,2022,31： 20-26）     

Studies of Primary Angle Qosure Glaucoma in China

The resent researches on primary angle closure glaucoma (PACG) in China were reviewed. The prevalence of PACG (0.41%) in chinese is between the Caucasian and Eskimos, and chronic type is the dominant type in PACG. However, with the economic development and medical care improvements, the prevalence condition of PACG may change; several researches discovered that the mechanism of PACG, especially the chronic type, is not only because of pupil-blocking but also closely related to the mechanism of crowding of peripheral iris and the anterior location of the ciliary body. We supposed that PACG can be divided into several subtypes based on this machnism. Also, we believe that the use of ultrasound biomicroscopy (UBM) and ophthalmic laser in China has promoted the research of PACG and improved the level of prevention and treatment of PACG. Eye Science 1997; 13 : 120- 124.     

Feasibility of laser trabeculoplasty in angle closure glaucoma: a review of favourable histopathological findings in narrow angles

Selective laser trabeculoplasty (SLT) has been indicated as a safe and efficient treatment for primary open‐angle glaucoma; however, recent studies have also shown positive results with the use of SLT in some clinical conditions related to primary angle‐closure glaucoma (PACG). Despite the potential benefits of SLT in selected cases of PACG, the mechanisms underlying the modifications in the trabecular meshwork tissue of patients with PACG are poorly understood. This narrative review approached both the current, limited knowledge about the histological changes observed in different forms of PACG and the clinical results of SLT treatment for PACG. Favourable outcomes of SLT in patients with PACG, specifically in areas of non‐occluded angle, need further substantiation through large controlled clinical trials. A deeper understanding of the biomolecular changes of those areas is essential to improve both laser technical details and the clinical efficacy of SLT therapy.     

OCT对激光周边虹膜切开术治疗原发性闭角型青光眼效果的评价

目的：通过光学相干断层扫描技术(optical coherence tomography,OCT)观察不同临床类型原发性闭角型青光眼(primary angle-closure glaucoma,PACG)行激光周边虹膜切开术(laser peripheral iris, LPI)前、后前房角开放距离变化,评价治疗效果。方法：选择明确诊断为PACG患者46例50眼,其中急性闭角型青光眼临床前期及缓解期眼26例27眼,慢性闭角型青光眼20例23眼,行LPI治疗,通过OCT分别检查术前、术后2周距巩膜突500及750μm处前房角开放距离,采用配对t检验。结果：急性闭角型青光眼LPI术前、术后2周前房角开放距离差异有统计学意义(P<0.05);慢性闭角型青光眼术前、术后2周前房角开放距离差异无统计学意义(P>0.05)。结论：急性闭角型青光眼LPI术后前房角开放距离增加,治疗效果较好;慢性闭角型青光眼LPI术后前房角开放距离增加不明显,术后仍存在前房角闭塞趋向。