Friedman D S, Vedula S S
Wilmer Eye Institute / Johns Hopkins University, Ophthalmology Department, 600 North Wolfe Street, Wilmer 120, Baltimore, MD 21287, USA.
Cochrane Database Syst Rev. 2006 Jul 19(3):CD005555. doi: 10.1002/14651858.CD005555.pub2.
Angle-closure glaucoma is characterized by obstruction to the outflow of aqueous humor and consequent rise in intraocular pressure. The obstruction may result from an anatomical predisposition of the eye or may be due to pathophysiologic processes in any part of the eye. The former is considered the primary form and the latter a secondary form of angle closure. Relative pupillary block obstructing free flow of aqueous from the posterior chamber of the eye to the anterior chamber is considered to be the most common mechanism of angle closure. Crowding of the angle is another mechanism, which often coexists with pupillary block. This can result from an anterior placement of the lens due to an increase in the thickness of the lens (as occurs with aging), anterior displacement by a posterior force (for example choroidal effusion), or laxity of the zonules.
The objective of this review was to assess the effectiveness of lens extraction for chronic primary angle-closure glaucoma compared with other interventions for the condition in people without past history of acute-angle closure attacks.
We searched CENTRAL (2005, Issue 3), MEDLINE (1950 to April 2006), EMBASE (1980 to April 2006), and LILACS (to August 2005). We searched the reference lists of included studies and used the Science Citation Index database.
In the absence of any randomized trials we included non-randomized studies comparing lens extraction with other treatment modalities for chronic primary angle-closure glaucoma including, but not limited to, laser iridotomy, medications, and laser iridoplasty. We excluded studies with a case-series design.
Two authors independently extracted data on methodological quality of the included studies, outcomes for the review, and study characteristics including participant characteristics, interventions, and sources of funding. Differences were resolved through discussion.
We found no randomized trials evaluating the effects of lens extraction as a treatment for chronic primary angle-closure glaucoma. Two non-randomized comparative studies included in the review have several methodological flaws including selection bias. While these studies and other non-comparative studies provide information on biological plausibility and treatment effect they do not provide proof of effectiveness. Also, they do not address the question of how primary lens extraction compares with other treatments for chronic primary angle-closure glaucoma.
AUTHORS' CONCLUSIONS: There is no evidence from good quality randomized trials or non-randomized studies of the effectiveness of lens extraction for chronic primary angle-closure glaucoma.
闭角型青光眼的特征是房水流出受阻，继而眼压升高。这种阻塞可能源于眼睛的解剖学易患因素，也可能是由于眼部任何部位的病理生理过程所致。前者被认为是原发性闭角型青光眼，后者是继发性闭角型青光眼。相对性瞳孔阻滞阻碍房水从眼球后房自由流入前房被认为是闭角型青光眼最常见的机制。房角拥挤是另一种机制，常与瞳孔阻滞并存。这可能是由于晶状体厚度增加（如随着年龄增长而发生）导致晶状体前移、后向力（如脉络膜积液）引起的前移位或悬韧带松弛所致。
本综述的目的是评估晶状体摘除术治疗慢性原发性闭角型青光眼相对于其他治疗方法的有效性，这些患者既往无急性闭角型青光眼发作史。
我们检索了Cochrane系统评价数据库（CENTRAL，2005年第3期）、医学索引数据库（MEDLINE，1950年至2006年4月）、荷兰医学文摘数据库（EMBASE，1980年至2006年4月）和拉丁美洲及加勒比地区卫生科学数据库（LILACS，至2005年8月）。我们检索了纳入研究的参考文献列表，并使用了科学引文索引数据库。
由于缺乏任何随机试验，我们纳入了非随机研究，这些研究比较了晶状体摘除术与慢性原发性闭角型青光眼的其他治疗方式，包括但不限于激光虹膜切开术、药物治疗和激光虹膜成形术。我们排除了病例系列设计的研究。
两位作者独立提取了纳入研究的方法学质量数据、综述的结局以及研究特征，包括参与者特征、干预措施和资金来源。通过讨论解决分歧。
我们未发现评估晶状体摘除术治疗慢性原发性闭角型青光眼效果的随机试验。本综述纳入的两项非随机对照研究存在一些方法学缺陷，包括选择偏倚。虽然这些研究及其他非对照研究提供了生物学合理性和治疗效果方面的信息，但并未提供有效性的证据。此外，它们未解决原发性晶状体摘除术与慢性原发性闭角型青光眼的其他治疗方法相比如何的问题。
高质量的随机试验或非随机研究均未提供证据证明晶状体摘除术治疗慢性原发性闭角型青光眼的有效性。
