Screening for prevention of optic nerve damage due to chronic open angle glaucoma

  • Review
  • Intervention

Authors


Abstract

Background

Open angle glaucoma (OAG) is a primary, progressive optic neuropathy; the onset is without symptoms and progression occurs silently until the advanced stages of the disease, when it affects central vision. The blindness caused by OAG is irreversible. It has often been assumed to be a condition that fulfils the criteria for population screening, although this has not been supported by other in-depth non-systematic reviews. The focus of this review was to examine the evidence for the effectiveness of screening for OAG.

Objectives

To determine the impact of screening for OAG compared with opportunistic case findings or current referral practices on the prevalence of and the degree of optic nerve damage due to OAG in screened and unscreened populations.

Search methods

We included any randomised controlled trial (RCT) evaluating population-based screening programmes for OAG with a minimum one year follow up. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library, Issue 4, 2008), MEDLINE (January 1950 to January 2009), EMBASE (January 1980 to January 2009), the UK Clinical Trials Gateway (UKCTG) and ZETOC (January 1993 to January 2009). There were no language or date restrictions in the search for trials. The electronic databases were last searched on 12 January 2009.

Selection criteria

We planned to include RCTs, including cluster RCTs.

Data collection and analysis

Two review authors independently assessed the study abstracts identified by the electronic searches. We did not find any trials that met the inclusion criteria.

Main results

As no trials were identified, no formal analysis was performed.

Authors' conclusions

On the basis of current evidence, population-based screening for chronic OAG cannot be recommended, although much can be done to improve awareness and encourage at risk individuals to seek testing. In wealthy countries with equitable access to high quality eye care and health education, blindness from chronic OAG should become increasingly rare; much greater challenges face poor and emerging economies and countries where there are substantial health and wealth inequalities. Effectiveness of screening for OAG can be established only by high quality RCTs.

摘要

背景

預防隅角開放性青光眼造成視神經傷害的篩檢

隅角開放性青光眼(OAG)是一種原發性,漸進性的視神經病變通常開始時並無症狀且無聲息進展直到疾病後期已經影響中央視力.隅角開放性青光眼造成的眼盲是不可逆的.它已經通常被認定符合全民篩檢的條件,雖然這尚未被其它獨立非系統性的回顧所支持.此回顧的重點在於檢定隅角開放性青光眼篩檢的效益之證據.

目標

比較隨機發現的個案或目前轉診工作在有篩檢及未篩檢的群眾的神經因隅角開放性青光眼而受傷盛行率與程度來評估隅角開放性青光眼篩檢的影響.

搜尋策略

我們含括任何族群基礎評估隅角開放性青光眼篩檢計劃並至少追蹤一年的randomised controlled trial (RCT). 我們搜尋在Cochrane Library (包含Cochrane Eyes and Vision Trials Register) (Issue 1, 2006) 內的Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1950至 2006二月)及 EMBASE (1988 至2006二月).我們也尋找 National Research Register (Issue 1, 2006) 及 Zetoc 來取得灰色文獻(29 June 2006). 在此電子搜尋並無語言或日期的限制.

選擇標準

我們計劃包含RCTs,及cluster RCTs.

資料收集與分析

兩位作者獨立依照電子搜尋評估研究的摘要.我們發現沒有任何符合含括條件的研究.

主要結論

因沒有任何研究被確認,沒施行正式的分析.

作者結論

在目前證據基礎, 對慢性隅角開放性青光眼群眾為基礎的篩檢並不被建議, 雖然可以達到增加警覺且促進有危險的人去接受檢查. 更多的挑戰是面對那些大多數健康及富裕狀況不均等的貧窮及新興的經濟和國家.對慢性隅角開放性青光眼的篩檢的效果僅能以高品質的RCTs來確立.

翻譯人

本摘要由高雄榮民總醫院王曉萍翻譯。

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

總結

篩檢來預防隅角開放性青光眼造成視神經傷害.隅角開放性青光眼是白歐洲及非洲人民最常見的青光眼且是造成不可逆性眼盲的最常見原因. 它的發生是漸進的且進展是無症狀的直到狀況已遠遠進展而中央視力已喪失.因此, 隅角開放性青光眼被認為是需被篩檢的狀況但缺乏良好的證據來支持.發生隅角開放性青光眼的危險因子有年齡的增加,眼內壓上升及家族史. 最常見於非洲裔的人們, 可能於較早的年紀就得到且較有侵犯性. 視野(週邊視力)逐漸喪失但視神經外表的變化(表現於於眼睛後面內側)通常先發生. 上升的眼內壓通常不表現且很多壓力上升並無青光眼. 對此疾病的檢驗是檢查視神經,測眼壓及視野的評估. 篩檢的挑戰是去發現那些疾病的階段診斷是沒有疑問的且若不治療有危險變為眼盲的人們. 此回顧的目的是去評估篩檢對於因隅角開放性青光眼造成視神經傷害的盛行率與嚴重程度的影響. 我們搜尋篩不篩檢隅角開放性青光眼的randomised controlled trials (RCTs),因為對於想要於人群中預防因一個疾病造成不好效應的篩檢的效果只能用RCT來證實. 我們發現有1360研究報告但沒有篩檢的RCTs. 因此,並無足夠的證據來建議群眾為基礎的隅角開放性青光眼篩檢.然而可以達到增加警覺且促進有危險的人去接受檢查.在有平等機會得到高品質眼睛照護及健康教育的富裕國家,因慢性隅角開放性青光眼而造成眼盲現象應漸漸變少. 更多的挑戰是面對那些無法均等得到好的健康照護的貧窮及新興的經濟和國家.對慢性隅角開放性青光眼的篩檢來預防視神經受傷及最後預防眼盲的可能效果應以篩檢的高品質的RCTs來檢定.

Plain language summary

Screening to prevent damage to the optic nerve due to open angle glaucoma

Open angle glaucoma (OAG) is the commonest type of glaucoma in white European and African people and is the commonest cause of irreversible blindness. Its onset is insidious and progression symptomless until the condition is far advanced and central vision is lost. Because of this, OAG is assumed to be a condition which should be screened for, but good evidence to support this is lacking. Risk factors for developing OAG include increasing age, raised pressure inside the eye and a history in the family. It is more common in people with African origin, may come on at an early age and is more aggressive. The field of vision (side vision) is gradually lost but changes in the appearance of the optic nerve (where it appears inside the back of the eye) usually occur first. Raised pressure inside the eye may not be present and many with raised pressure do not have glaucoma. Tests for the disease are examination of the optic nerve, measurement of eye pressure and visual field assessment. The challenge of screening is to find people with the disease at a stage when the diagnosis is not in doubt and at risk of going blind if left untreated.

The aim of this review was to determine the impact of screening on the prevalence and severity of optic nerve damage due to OAG. We searched for randomised controlled trials (RCTs) of screening versus no screening for OAG because effectiveness of screening as a means of preventing the ill effects of a disease in a population can only be demonstrated by RCTs. We identified 1360 reports of studies but none were RCTs of screening. Therefore, there is insufficient evidence to recommend population based screening for OAG. However much can be done to improve awareness of the condition and encourage those at higher risk to seek testing. In wealthy countries where there is access to high quality eye care and good health education, blindness from OAG should become increasingly rare. Much greater challenges face poor and emerging economies and countries where there is not equal access to good healthcare. The potential effectiveness of screening for OAG in preventing optic nerve damage and ultimately preventing blindness should be tested by high quality RCTs of screening.

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