Laser photocoagulation for neovascular age-related macular degeneration
Editorial Group: Cochrane Eyes and Vision Group
Published Online: 18 JUL 2007
Assessed as up-to-date: 29 MAR 2007
Copyright © 2009 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
How to Cite
Virgili G, Bini A. Laser photocoagulation for neovascular age-related macular degeneration. Cochrane Database of Systematic Reviews 2007, Issue 3. Art. No.: CD004763. DOI: 10.1002/14651858.CD004763.pub2.
- Publication Status: Edited (no change to conclusions)
- Published Online: 18 JUL 2007
Laser photocoagulation was the first treatment introduced to try to halt the progression of neovascular age-related macular degeneration (AMD), in which newly formed vessels or choroidal neovascularisation (CNV) grow under the macula leading to the occurrence of a scotoma or blind spot in the central visual field.
The aim of this review was to examine the effects of laser photocoagulation for neovascular AMD.
We searched the CENTRAL, MEDLINE, EMBASE, LILACS, NRR and ZETOC in March 2007.
We included randomised trials of laser photocoagulation in people with CNV due to AMD.
Data collection and analysis
Two authors independently extracted the data. The risk ratio (RR) of severe visual loss (loss of six or more lines of visual acuity) was estimated at three months and two years after treatment.
Fifteen trials were included in the review (2064 participants). Three types of photocoagulation were used in the trials: direct photocoagulation of the entire CNV (11 trials), perifoveal photocoagulation (one trial) and grid photocoagulation (three trials). In 12 trials the control group was observation only. One trial compared photocoagulation to submacular surgery and two trials compared different lasers. Data on the progression of visual loss could be extracted from five of the eight trials of direct photocoagulation of the CNV versus observation. The treatment effect was in the direction of harm in all studies at three months follow up (RR 1.41, 95% confidence intervals (CI) 1.08 to 1.82). After two years the treatment effect was in the direction of benefit (RR 0.67, 95% CI 0.53 to 0.83). These studies were clinically heterogenous with participants having CNV lesions in different locations and different baseline visual acuities. There was little evidence of statistical heterogeneity at three months but substantial statistical heterogeneity at two years. However, all treatment effects in the individual trials were in the direction of benefit. One study comparing perifoveal photocoagulation or observation of subfoveal CNV found benefits that were statistically significant only at two years (RR 0.36, 95% CI 0.18 to 0.72). Other comparisons did not demonstrate differences.
In the medium to long term laser photocoagulation of CNV slows the progression of visual loss in people with neovascular AMD. However, it is associated with an increased risk of visual loss immediately after treatment and this period may be longer in people with subfoveal AMD. With the advent of modern pharmacological therapies, and concern for the impact of iatrogenic scotoma in subfoveal CNV, laser photocoagulation of subfoveal CNV is not recommended. No studies have compared photocoagulation with modern pharmacological agents for AMD for non-subfoveal CNV.
Plain language summary
Laser photocoagulation for treating neovascular age-related macular degeneration
Laser photocoagulation was the first treatment introduced to try to halt the progression of neovascular age-related macular degeneration (AMD), in which newly formed vessels or choroidal neovascularisation (CNV) grow under the macula leading to the occurrence of a scotoma or blind spot in the central visual field. One disadvantage is that it causes a dark spot in the visual field. This is of concern when the lesion is in the centre of the macula. Fifteen trials involving a total of 2064 participants were included. Three types of photocoagulation were used in the trials: direct photocoagulation of the entire CNV, perifoveal photocoagulation and grid photocoagulation. Control groups in the trials included observation only, submacular surgery and different lasers. This review found that the use of photocoagulation is effective for people with lesions that are outside the centre of the macula. However, these types of lesions are less common in AMD. Severe loss of vision can be prevented in about one in six people.
雷射光凝固療法是第一種治療方式用來嘗試中斷新生血管的老年性黃斑退化(agerelated macular degeneration (AMD))的進展，新生血管的AMD為黃斑下生長新形成的血管或脈絡膜新生血管(choroidal neovascularisation (CNV))導致中央視野發生盲點或失明點。
兩名作者分別摘錄資料。估計治療後三個月與兩年的嚴重視力喪失(六行或以上的視力損失)的相對風險(risk ratio (RR))。
15篇試驗納入回顧中(2064名研究對象)。試驗中使用三種類型的光凝固療法：全CNV的直接光凝固療法(11篇試驗)，中心窩周圍的光凝固療法(一篇試驗)及網格狀的光凝固療法(三篇試驗)。12篇試驗中其對照組只進行觀察。一篇試驗比較光凝固療法與黃斑視網膜新生血管摘除手術(submacular surgery)，而兩篇試驗比較不同的雷射方法。從CNV的直接光凝固療法對照觀察法的八篇試驗中摘錄五篇研究有關視力喪失進展的資料。三個月時，所有研究的治療效果具有不利的趨勢(RR為1.41，95% confidence intervals (CI)為1.08至1.82)。兩年後，治療的效果具有有利的趨勢(RR為0.67，95% CI為0.53至0.83)。這些研究具有臨床上的異質性，因為研究對象其CNV的病灶在不同的區域且有不同的基礎視力。三個月時有少量的證據顯示研究有統計異質性，但在兩年時有大量的統計異質性。然而，個別的試驗中所有的治療效果具有有利的趨勢。一篇研究比較中心窩周圍的光凝固療法或中心窩下CNV的觀察法發現只有在兩年時具有統計顯著效益(RR為0.36，95% CI為0.18至0.72)。其他比較組別沒有證實具有差異。
此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。