Medical versus surgical interventions for open angle glaucoma

 

Abstract

Background

Open angle glaucoma (OAG) is a common cause of blindness.

Objectives

To study the relative effects of medical and surgical treatment of OAG.

Search methods

We searched CENTRAL, MEDLINE, EMBASE, LILACS, BIOSIS, SIGLE, NRR, CINAHL, ZETOC to April 2007, reference lists of articles and also contacted researchers in the field.

Selection criteria

We included randomised controlled trials comparing medications with surgery in adults.

Data collection and analysis

Two authors independently assessed trial quality and extracted data. We contacted trial investigators for missing information.

Main results

Four trials involving 888 participants with previously untreated OAG were included. Surgery was Scheie's procedure in one trial and trabeculectomy in three trials. In three trials, primary medication was usually pilocarpine, in one trial a beta-blocker.

The most recent trial included participants with mild OAG. The risk of progressive visual field (VF) loss, after adjustment for cataract surgery, was not significantly different for medications compared with trabeculectomy (odds ratio (OR) 0.74; 95% CI 0.54 to 1.01). Trabeculectomy was associated with a higher risk of reduced visual acuity (OR 0.47, 95%% CI 0.31 to 0.74), and more eye discomfort than medication (P = 0.03).

In more severe OAG there is some evidence, from three trials, that medication was associated with more progressive VF loss and 6 to 9 mmHg less intraocular pressure (IOP) lowering than surgery. In the longer-term (two trials) the risk of failure of the randomised treatment was greater with medication than trabeculectomy (OR 3.90, 95% CI 1.60 to 9.53; HR 7.27, 95% CI 2.23 to 25.71). Medications and surgery have evolved since these trials were undertaken.

In three trials the risk of developing cataract was higher with trabeculectomy (OR 2.69, 95%% CI 1.64 to 4.42).

Methodological weaknesses were identified in all the trials.

Authors' conclusions

Evidence from one trial suggests, for mild OAG, that the risk of glaucoma progression up to five-years is not significantly different whether treatment is initiated with medication or trabeculectomy. Reduced vision, cataract and eye discomfort are more likely with trabeculectomy. There is some evidence, for more severe OAG, that initial medication (pilocarpine, now rarely used as first line medication) is associated with a greater risk of glaucoma progression than surgery. Surgery lowers IOP more than medication.

There was no evidence to determine the effectiveness of contemporary medication (prostaglandin analogues, alpha2-agonists and topical carbonic anhydrase inhibitors) compared with surgery in severe OAG, and in people of black ethnicity. More research is required.

 

Plain language summary

Medications or surgery for the treatment of open angle glaucoma (OAG)

Open angle glaucoma is the most common form of glaucoma and an important cause of blindness. Having a high intraocular pressure (IOP) is an important risk factor. Treatment for OAG aims to lower the IOP and thus reduce the risk of progressive loss of vision. Intraocular pressure can be lowered by medications (eye drops), laser therapy or surgery. There are many different types of eye drops available and these are compared in a recent Cochrane review (Vass 2007). Surgery for glaucoma has evolved in the last 40 years. The most common type is trabeculectomy, another type of operation involves inserting a tube, both types of surgery facilitate fluid drainage out of the eye. All these operations potentially lower the IOP, however, they may have complications during and after the operation and may fail in the long term due to scarring. Drainage surgery forms a 'bleb' i.e. small blister like elevation on the surface of the eye which can sometimes be uncomfortable. It is not clear whether medication or surgery is the better treatment for OAG. The purpose of this review was to review and assess evidence from randomised studies to compare treatment with medications with surgery in terms of how well they work, their relative safety and cost-effectiveness. Four relevant trials were identified, treating 888 people. Three studies were in the UK and one in the US. These trials had been initiated over many years from 1968 up to the most recent trial in 1993. The earlier trials used medications, and in one trial surgical techniques, that are now rarely used. Findings of these studies suggest that, in mild OAG, worsening of the condition was not different whether first treatment was medication or surgery, but surgery was associated with more eye discomfort, an increased risk of cataract and a slight reduction in distance vision at five years. In more severe glaucoma, surgery lowered IOP significantly more than medications (not widely used anymore) and reduced the risk of progressive loss of visual field. In three trials the risk of developing cataract was higher with surgery (trabeculectomy). There was insufficient evidence to determine how well more recently available medications work compared with surgery in more severe OAG, and which was the more cost-effective treatment option. More research is required.

 

摘要

背景

廣角性青光眼的藥物與手術介入措施

廣角性青光眼(Open angle glaucoma (OAG))是失明常見的主因之一。

目標

研究藥物與手術治療OAG的相對效果。

搜尋策略

我們檢索CENTRAL，MEDLINE，EMBASE，LILACS，BIOSIS，SIGLE，NRR，CINAHL，ZETOC至2007年4月止，文章的參考文獻，並連絡該領域的研究人員。

選擇標準

比較成人以藥物與手術治療的隨機對照試驗。

資料收集與分析

兩名作者分別獨立評估試驗品質並摘錄資料。聯繫試驗的研究人員以了解缺漏的資訊。

主要結論

納入四篇試驗，包含先前未曾治療OAG的888名研究對象。一篇試驗為Scheie的手術，而三篇試驗為青光眼濾過術。三篇試驗中，主要的藥物為pilocarpine，一篇試驗為β阻斷劑。最近的試驗納入輕微的OAG患者作為研究對象。在白內障手術矯正後，藥物治療的患者其漸進式視野喪失(visual field (VF))的風險相較於青光眼濾過術沒有顯著差異(odds ratio (OR)為0.74；95% CI為0.54至1.01)。相較於藥物治療，青光眼濾過術與高風險的視力減少(OR為0.47，95% CI為0.31至0.74)，及較多的眼睛不適(P = 0.03)有關。三篇試驗中有一些證據指出，對於較嚴重的OAG患者，相較於手術，藥物治療與較多的漸進式視野喪失及6至9mmHg的低眼壓風險有關。長期追蹤下(兩篇試驗)，藥物隨機治療失敗的風險比青光眼濾過術高(OR為3.90，95% CI為1.60至9.53；HR為7.27，95% CI為2.23至25.71)。自從這些試驗進行後，藥物及手術已有進步的發展。三篇試驗指出青光眼濾過術患者發展成白內障的風險較高(OR為2.69，95% CI為1.64至4.42)。已確定所有的試驗皆有方法學上的不足。

作者結論

一篇試驗的證據認為，對於輕微的OAG患者，不論一開始是使用藥物或青光眼手術治療，其五年內青光眼進展的風險不具有顯著差異。視力減少，白內障與眼睛不適比較有可能與青光眼濾過術有關。有一些證據指出，相較於手術，較嚴重的OAG患者其一開始使用藥物治療(pilocarpine，現在較少作為第一線用藥)與高風險的青光眼進展有關。相較於藥物治療，手術會降低IOP。相較於手術，沒有證據可以確定現有的藥物治療(前列腺素衍生物類，α2致效劑及局部的carbonic anhydrase抑制劑)對於嚴重的OAG患者以及黑人種族的效果，需要更多的研究。

翻譯人

本摘要由高雄榮民總醫院金沁琳翻譯。

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

總結

廣角性青光眼(OAG)的藥物或手術治療。廣角性青光眼是最常見的青光眼類型，且是導致失明的重要原因。高眼內壓是一項重要的危險因素。OAG的治療目的在於降低IOP並因此減少視力逐漸喪失的風險。可以經由藥物(點眼液)，雷射治療或手術來降低眼內壓。目前可取得許多不同類型的點眼液且最近的考科藍回顧有對其進行比較(Vass，2007年)。近40年來青光眼的手術已有進展。最常見的類型就是青光眼濾過術，其他類型的手術包含插入小管，這兩種手術皆可以促進眼睛的淚液引流。這些手術都有可能可以降低IOP，然而，在手術治療期間或治療後也許會產生併發症，且長時間後也許會因為傷口結痂造成治療失敗。引流手術會形成一個“皰疹”，如眼球表面升起小水泡，有時會造成眼睛不適。目前不清楚藥物或手術何者對於OAG的治療效果較佳。這篇回顧的目的為回顧並評估來自隨機試驗的證據，比較藥物與手術治療的運作方式，它們的相對安全性與成本效果。找到了四篇相關的試驗，共治療888名患者。三篇研究是在英國，一篇是在美國執行。這些試驗自1968年起至最近1993年已開始進行多年。較早的試驗使用藥物，現在則很少使用，而一篇試驗使用手術技術。這些研究結果認為，不論藥物治療或手術，對於輕微OAG患者的情況惡化皆沒有差異，但手術與較多的眼睛不適，五年內增加白內障風險及些微視力減少有關。在較嚴重的青光眼患者中，相較於藥物治療(不再被廣泛地使用)，手術可以顯著地降低IOP並減少視野逐漸喪失的風險。三篇試驗指出手術(青光眼濾過術)與發展白內障的高風險有關。沒有足夠的證據可以確定對於較嚴重的OAG患者，相較於手術，近期現有的藥物是如何運作，以及何種較具有成本效果，因此需要更多的研究。