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Laser treatment of drusen to prevent progression to advanced age-related macular degeneration

  • Review
  • Intervention

Authors


Abstract

Background

Drusen are amorphous yellowish deposits beneath the sensory retina. People with drusen, particularly large drusen, are at higher risk of developing age-related macular degeneration (AMD). The most common complication in AMD is choroidal neovascularisation (CNV), the growth of new blood vessels in the centre of the macula. The risk of CNV is higher among patients who are already affected by CNV in one eye.

It has been observed clinically that laser photocoagulation of drusen leads to their disappearance and may prevent the occurrence of advanced disease (CNV or geographic atrophy) associated with visual loss.

Objectives

To examine the effectiveness and adverse effects of laser photocoagulation of drusen in AMD.

Search methods

We searched CENTRAL, MEDLINE and EMBASE on 14 November 2008.

Selection criteria

Randomised controlled trials (RCTs) of laser treatment of drusen in AMD in which laser treatment had been compared with no intervention or sham treatment. Two types of trials were included. Some trials studied one eye of each patient (unilateral studies); other studies recruited patients with bilateral drusen and randomised one eye to photocoagulation or control and the fellow eye to the other group.

Data collection and analysis

Two review authors independently selected studies and extracted data. We pooled data from unilateral and bilateral studies using a random-effects model. For the bilateral studies, we estimated the within-patient correlation coefficient from one study and assumed it was valid for the others.

Main results

We found nine studies which randomised 2216 people: four unilateral trials, three bilateral trials and two trials that included both a unilateral and a bilateral study arm.

Overall, the studies were of moderate quality. Only half of the trials reported adequate allocation sequence generation, allocation concealment and masking of visual acuity outcome assessors.

Although two (of the nine) studies reported significant drusen disappearance at two years, photocoagulation did not appear to affect the development of CNV at two years follow up (nine studies, 1767 people followed up, odds ratio (OR) 1.04, 95% CI 0.71 to 1.51) or the loss of three or more lines of visual acuity (six studies, 1628 people followed up, OR 1.17, 95% CI 0.75 to 1.82).

Authors' conclusions

The trials included in this review confirm the clinical observation that laser photocoagulation of drusen leads to their disappearance. However, there is no evidence that this subsequently results in a reduction in the risk of developing CNV, geographic atrophy or visual acuity loss.

摘要

背景

雷射治療隱結預防年齡相關性黃斑退化病變

隱結是視網膜下的無定形的黃色沉積物。有隱結的病人,特別是有大型隱結的人,是產生年齡相關性黃斑病變(AMD)的高危險群。AMD最常見的併發症是脈絡膜新生血管(CNV),指新血管增生在黃斑中心。 一眼已得到CNV的病人再得到CNV的機會是較高的.臨床觀察顯示,雷射治療可以使隱結消失,並可能防止疾病的進展到與視覺喪失有關的晚期病變(CNV或地圖狀萎縮)。

目標

檢視雷射治療在AMD的隱結上的有效性和副作用。

搜尋策略

我們在2008年11月14日檢索了 CENTRAL, MEDLINE 和EMBASE

選擇標準

雷射治療治療AMD的隱結隨機對照試驗(RCT),在其中比較雷射治療,不干預或假治療的結果。兩種類型的試驗被納入。有些試驗研究每個病人一隻眼睛(單側的研究),其他研究招募患雙側隱結的病人,隨機分配其中一隻眼睛為雷射治療組而另一側眼為控制組。

資料收集與分析

兩個獨立的回顧作者選擇研究和提取數據。我們使用隨機效應模式匯集包含單眼和雙眼的研究的數據。對於雙眼的病人的研究,我們從其中一個研究評估病人間的相關係數並估計它在其他研究上也是可信的。

主要結論

我們發現其中9個研究裡隨機 2216人:4項單眼的研究,三個雙眼的研究還有兩個是包括單眼和雙眼的研究。總結來說,這些研究的質量中等。只有一半的試驗報告充分分配序列的產生,分配隱藏和掩蓋的的視力結果。雖然其中2個研究(9個研究裡)報告顯著隱結消失了兩年,雷射燒灼術似乎並沒有影響兩年內發展的新生血管(9項研究,追蹤1767人,勝算比(OR)為 1.04,95% CI 0.71至1.51)或損失三個或更多行的視力(6項研究,追蹤1628人,OR 1.17,95% CI 0.75至1.82)。

作者結論

包括在這次回顧的這些試驗,證實臨床觀察雷射燒灼術可導致隱結消失。但是,沒有證據表明這樣接著可減少CNV發展,地圖狀萎縮或視力喪失的風險。

翻譯人

本摘要由高雄榮民總醫院王立峰翻譯。

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

總結

隱結是視網膜下的無定形的黃色沉積物。有隱結的病人,特別是有大型隱結的人,是產生年齡相關性黃斑病變(AMD)的高危險群。AMD最常見的併發症是新血管在黃斑中心的增生(脈絡膜新生血管或CNV也被稱為‘濕性 AMD’)和光感受器損耗(地圖狀萎縮)。據臨床觀察,雷射燒灼術可以使隱結消失。因此有人建議,以雷射燒灼術消除隱結來防止CNV的發展和地圖狀萎縮。這項審查包括來自 9個中等質量試驗的數據。這些研究證實了臨床觀察,雷射燒灼術可以使隱結消失。但是,沒有證據表明雷射燒灼術消除隱結可防止CNV的發展和地圖狀萎縮或視力喪失的風險。

Plain language summary

Laser treatment of drusen to prevent progression to advanced age-related macular degeneration

Drusen are amorphous yellowish deposits beneath the sensory retina. People with drusen, particularly extensive large drusen, are at higher risk of developing age-related macular degeneration (AMD). The most common complications in AMD are the growth of new blood vessels in the centre of the macula (choroidal neovascularisation or CNV also known as 'wet AMD') and loss of photoreceptors (geographic atrophy). It has been observed clinically that laser photocoagulation of drusen leads to their disappearance. Laser photocoagulation of drusen has thus been proposed as a way to prevent the development of CNV and geographic atrophy. This review included data from nine trials of moderate quality. These studies confirmed the clinical observation that laser photocoagulation of drusen leads to their disappearance. However, there was no evidence that laser photocoagulation of drusen reduced the risk of developing CNV, geographic atrophy or visual acuity loss.