Intervention Review

Lens extraction for chronic angle-closure glaucoma

  1. David Friedman1,*,
  2. Satyanarayana S Vedula2

Editorial Group: Cochrane Eyes and Vision Group

Published Online: 19 JUL 2006

Assessed as up-to-date: 7 MAR 2006

DOI: 10.1002/14651858.CD005555.pub2


How to Cite

Friedman D, Vedula SS. Lens extraction for chronic angle-closure glaucoma. Cochrane Database of Systematic Reviews 2006, Issue 3. Art. No.: CD005555. DOI: 10.1002/14651858.CD005555.pub2.

Author Information

  1. 1

    Wilmer Eye Institute / Johns Hopkins University, Ophthalmology Department, Baltimore, USA

  2. 2

    Johns Hopkins Bloomberg School of Public Health, Cochrane Eyes and Vision Group US Project, Baltimore, MD, USA

*David Friedman, Ophthalmology Department, Wilmer Eye Institute / Johns Hopkins University, 600 North Wolfe Street, Wilmer 120, Baltimore, 21287, USA. david.friedman@jhu.edu.

Publication History

  1. Publication Status: Edited (no change to conclusions)
  2. Published Online: 19 JUL 2006

SEARCH

 

Abstract

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

Background

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.

Objectives

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.

Search methods

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.

Selection criteria

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.

Data collection and analysis

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.

Main results

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.

 

Plain language summary

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

Removal of the lens as a treatment for chronic primary angle-closure glaucoma

Chronic primary angle-closure glaucoma results in debilitating loss of vision. Lens extraction or removal of the lens in this condition is thought to improve drainage of aqueous humor from the eye. This review evaluated available evidence of effectiveness of lens extraction as a treatment for people with chronic primary angle-closure glaucoma. No randomized trials were found. Subsequently, as stated in the protocol for this review, two non-randomized trials were included. Both studies were of poor methodological quality. There is no published evidence of effectiveness of lens extraction as a treatment option for chronic primary angle-closure.

 

摘要

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

背景

水晶體摘除用於治療慢性隅角閉鎖性青光眼

隅角閉鎖性青光眼的特徵在於房水的外流受阻塞而導致眼壓升高。阻塞的原因可能導因於眼睛本身解剖構造的問題或眼球病理及生理機轉的問題。若是前者,則為原發性隅角閉鎖;若為後者,則屬續發性隅角閉鎖。最常造成隅角閉鎖的原因則是相對性瞳孔阻斷導致房水無法從後房流至前房。隅角狹窄則是另一個常與瞳孔阻斷並存的致病機轉。這些現象可能導因於水晶體的厚度增加(隨著年齡增加),水晶體受後方推力而前移(例如脈絡膜滲出液),或水晶體懸韌帶鬆弛。

目標

這篇回顧性文章的目的在於針對過去不曾有過急性發作的隅角閉鎖性青光眼患者,比較其對於水晶體摘除術與其他治療方法的成效。

搜尋策略

我們總共搜尋了CENTRAL (2005, Issue 3), MEDLINE (1950 to April 2006), EMBASE (1980 to April 2006), and LILACS (to August 2005)等資料庫。此外我們也搜尋了引用研究的參考文獻以及Science Citation Index 資料庫。

選擇標準

由於沒有任何的隨機分配試驗可供參考,所以我們引用了非隨機分配的試驗。試驗的內容主要(但非侷限)在比較水晶體摘除術與虹膜切開術、藥物治療及雷射虹膜整形術的效果。個案追蹤研究則不在我們的選擇範圍內。

資料收集與分析

兩位作者各自進行資料分析,包含引用研究的統計品質、回顧的成果、及研究的特性(諸如受試者的特徵、介入方式及經費來源)。若有意見分歧則以討論來解決。

主要結論

我們無法找到任何關於評估以水晶體摘除術治療原發性隅角閉鎖性青光眼的隨機分配試驗。引用的非隨機分配試驗中有兩個有許多諸如選擇偏差的統計學瑕疵。這些被引用的研究及其他非比較性的研究僅能提供生物學上的可信性及治療的效果,卻無法證明其研究的可效性。此外,這些研究也無法回答關於慢性原發性隅角閉鎖性青光眼如何比較直接水晶體摘除術與其他治療的成效。

作者結論

沒有良好的隨機分配試驗能提供證據來證明以水晶體摘除術治療原發性隅角閉鎖性青光眼是有效的。

翻譯人

本摘要由高雄榮民總醫院畢勇賢翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

水晶體摘除用於治療慢性隅角閉鎖性青光眼 慢性原發性隅角閉鎖青光眼會造成視力逐漸消失。一般認為水晶體摘除術能夠促進眼內房水的排出。本篇回顧性文章審視了現有對於以水晶體摘除術治療慢性於較閉鎖青光眼的文獻。目前尚未有隨機分配試驗結果可供參考。此外,如前所述,本篇文章引用了兩個非隨機分配試驗。兩者皆有統計學上的瑕疵。目前尚未有足夠的證據顯示水晶體摘除術對於治療慢性隅角閉鎖性青光眼是有效的。