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Photodynamic therapy for neovascular age-related macular degeneration

  • Review
  • Intervention

Authors


Abstract

Background

In neovascular age-related macular degeneration (AMD) new vessels grow under the retina distorting vision and leading to scarring. This is exacerbated if the blood vessels leak. Photodynamic therapy (PDT) has been investigated as a way to treat the neovascular membranes without affecting the retina.

Objectives

The aim of this review was to examine the effects of PDT in the treatment of neovascular AMD.

Search methods

We searched CENTRAL (Issue 2, 2009), MEDLINE (1966 to April 2009) and EMBASE (1980 to April 2009). We contacted experts in the field and searched the reference lists of relevant studies.

Selection criteria

We included randomised trials of PDT in people with choroidal neovascularisation due to AMD.

Data collection and analysis

Two authors independently extracted the data. Risk ratios were combined using a random-effects model after testing for heterogeneity.

Main results

Four trials (1429 participants) comparing PDT with verteporfin to PDT with 5% dextrose in water were included in this review. Participants received on average five treatments over two years. The risk ratio of losing 3 or more lines of visual acuity at 24 months comparing the intervention with the control group was 0.80 (95% confidence interval (CI) 0.73 to 0.88). The risk ratio of losing 6 or more lines of visual acuity at 24 months comparing the intervention with the control group was 0.66 (95% CI 0.56 to 0.83). The results at 12 months were similar to those at 24 months. The most serious adverse outcome, severe visual acuity decrease within one week of treatment, occurred in 11 per 1000 patients (95% CI 3 to 48). Infusion related back pain was experienced by 20 per 1000 (95% CI 6 to 70). Two further trials compared different treatment regimens: standard versus delayed light application; retreatment every two months versus every three months. Neither trial demonstrated differences in effectiveness. The overall quality of the evidence included in this review was considered to be high. Five out of the six trials were funded by the manufacturers of verteporfin.

Authors' conclusions

Photodynamic therapy in people with choroidal neovascularisation due to AMD is effective in preventing clinically significant visual loss with a relative risk reduction of approximately 20%. Modified treatment regimens have not convincingly shown increased effectiveness. There was no evidence on quality of life and little on cost.

摘要

背景

光動力療法對於新生血管年齡相關性黃斑病變的效果

在新生血管年齡相關性黃斑病變,新生血管在視網膜下生長使視覺扭曲並留下疤痕.這些在血管滲漏時會更加嚴重.光動力療法已經被研究認為是治療新生血管膜且不會影響視網膜的方法.

目標

此文獻回顧的目的在檢驗光動力療法對於新生血管年齡相關性黃斑病變的治療效果.

搜尋策略

我們搜尋CENTRAL (Issue 1, 2007), MEDLINE (1966 to March 2007), EMBASE (1980 to March 2007). 我們與此領域的專家接洽並尋找相關研究參考文獻目錄.

選擇標準

我們含括光動力療法在因新生血管年齡相關性黃斑病變而有脈絡叢新生血管的患者的隨機試驗.

資料收集與分析

兩位作者獨立擷取資料.在檢驗異質性後使用fixedeffect model來加乘Risk ratios.

主要結論

確認的三個被刊登的研究隨機分配1022 個參與者至verteporfin 治療及相較的 5% 葡萄糖水. 這些 TAP 及 VIP 試驗由相同的觀察者運用大部分相同的臨床中心及由verteporfin製造公司提供經費.在第一次治療後12及24個月收集結果. 參與者平均在兩年內接受五次治療. 在24個月治療組相較於控制組視力減退大於或等於3行的風險比率為0.77 (95% 信賴區間 0.69 至o 0.87). 在24個月治療組相較於控制組視力減退大於或等於6行的風險比率 0.62 (95% 信賴區間0.50 至 0.76). 在12個月的結果與24個月時相同. 最嚴重的不良結果, 急性 (在治療7天內) 嚴重視力減退,約50個病人有一個發生. 有一些從最近的VIM 試驗得到的結論可以加入此 metaanalysis,但並無法大大的影響結果.

作者結論

光動力療法對於因老年黃斑病變造成脈絡膜新生血管的患者在預防視力減退方面效果仍有質疑,療效與潛在的副作用仍應密切觀察.需建立進一步verteporfin的獨立試驗來看此研究的的結論是否一致並檢驗尚未被提到的重要問題,特別是生活品質與費用. 然而, 對老年黃斑病變的新處置的出現使的這些變的不可行.

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

光動力療法對於年齡相關性黃斑病變的治療.年齡相關性黃斑病變主要侵襲黃斑部,視網膜(眼睛內部感受光線的地方)的中央. 一種稱為’濕性’ 或新生血管的年齡相關性黃斑病變, 因黃斑部有新生血管生成. 這些會造成眼底滲漏或結疤使視力減退. 光動力療法包含靜脈注射化學物質,當這些化學物質流經眼內新生血管時經光線照射. 這些化學物質活化後會破壞新生血管但不傷眼睛. 這目的是活化這些化學物質以足夠破壞血管但不會傷害眼睛. 此回顧包含三個隨機試驗共含有1022個參與者. 這三個試驗都比較 verteporfin 治療與5%葡萄糖水. 此回顧發現光動力療法可能減少因新生血管年齡相關性黃斑病變造成的視力損失的證據. 雖然需要更多的研究, 隨著對年齡相關性黃斑病變的新處置的出現, 不太可能做到.

Plain language summary

Photodynamic therapy for treating age-related macular degeneration

Photodynamic therapy involves injecting a photosensitive chemical (verteporfin) into the blood stream then radiating light onto the affected area of the retina as the chemical flows through the eye. The chemical is activated enough to treat neovascular or "wet" age-related macular degeneration by sealing the new blood vessels at the back of the eye. This review includes four randomised trials involving 1429 participants. All four trials compared verteporfin therapy to 5% dextrose water (placebo treatment). Photodynamic therapy reduces the risk of vision loss caused by "wet" age-related macular degeneration. More people treated with verteporfin also experienced improvements in vision compared to the placebo group, however, the absolute numbers experiencing vision improvement after this treatment was low (80 per 1000). A small number of people may experience acute vision loss within one week after treatment (in approximately 1 in 100 people) and infusion related back pain can occur (in approximately 1 in 50 people).

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