Evans J R
London School of Hygiene & Tropical Medicine, International Centre for Eye Health, Keppel Street, London, UK, WC1E 7HT.
Cochrane Database Syst Rev. 2006 Apr 19(2):CD000254. doi: 10.1002/14651858.CD000254.pub2.
It has been proposed that antioxidants may prevent cellular damage in the retina by reacting with free radicals that are produced in the process of light absorption.
The objective of this review was to assess the effects of antioxidant vitamin or mineral supplementation, or both, on the progression of age-related macular degeneration (AMD).
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2005, Issue 4); MEDLINE (1966 to January 2006); SIGLE (1980 to March 2005); EMBASE (1980 to January 2005); NRR (2005, Issue 4); AMED (1985 to January 2006); and PubMed (24 January 2006 covering last 60 days), reference lists of identified reports and the Science Citation Index. We contacted investigators and experts in the field for details of unpublished studies.
We included randomised trials comparing antioxidant vitamin or mineral supplemention (alone or in combination) to a control intervention in people with AMD.
The author extracted data and assessed trial quality. Where appropriate, data were pooled using a random-effects model unless three or fewer trials were available in which case a fixed-effects model was used.
Eight trials were included in this review. The majority of people were randomised in one trial (AREDS in the USA) that found a beneficial effect of antioxidant (beta-carotene, vitamin C and vitamin E) and zinc supplementation on progression to advanced AMD (adjusted odds ratio 0.68, 99% confidence interval 0.49 to 0.93). People taking supplements were less likely to lose 15 or more letters of visual acuity (adjusted odds ratio 0.77, 99% confidence interval 0.58 to 1.03). Hospitalisation for genito-urinary problems was more common in people taking zinc and yellowing of skin was more common in people taking antioxidants. The other trials were, in general, small and the results were inconsistent.
AUTHORS' CONCLUSIONS: The evidence as to the effectiveness of antioxidant vitamin and mineral supplementation in halting the progression of AMD comes mainly from one large trial in the USA. The generalisability of these findings to other populations with different nutritional status is not known. Further large, well-conducted randomised controlled trials in other populations are required. Long-term harm from supplementation cannot be ruled out. Beta-carotene has been found to increase the risk of lung cancer in smokers; vitamin E has been associated with an increased risk of heart failure in people with vascular disease or diabetes.
有人提出抗氧化剂可通过与光吸收过程中产生的自由基发生反应来预防视网膜细胞损伤。
本综述的目的是评估补充抗氧化维生素或矿物质，或两者同时补充，对年龄相关性黄斑变性（AMD）进展的影响。
我们检索了《考克兰系统评价数据库》（2005年第4期）中的考克兰对照试验中心注册库（CENTRAL）；MEDLINE（1966年至2006年1月）；SIGLE（1980年至2005年3月）；EMBASE（1980年至2005年1月）；《营养与饮食文摘数据库》（2005年第4期）；《联合和补充医学数据库》（1985年至2006年1月）；以及PubMed（截至2006年1月24日，涵盖过去60天），已识别报告的参考文献列表和《科学引文索引》。我们联系了该领域的研究人员和专家以获取未发表研究的详细信息。
我们纳入了比较抗氧化维生素或矿物质补充剂（单独或联合使用）与AMD患者对照干预措施的随机试验。
作者提取数据并评估试验质量。在适当情况下，使用随机效应模型合并数据，除非仅有三项或更少试验，在这种情况下使用固定效应模型。
本综述纳入了八项试验。大多数人被纳入一项试验（美国的年龄相关性眼病研究[AREDS]），该试验发现抗氧化剂（β-胡萝卜素、维生素C和维生素E）和锌补充剂对进展为晚期AMD有有益作用（调整后的优势比为0.68，99%置信区间为0.49至0.93）。服用补充剂的人视力丧失15行或更多行的可能性较小（调整后的优势比为0.77，99%置信区间为0.58至1.03）。服用锌的人泌尿生殖系统问题住院更为常见，服用抗氧化剂的人皮肤发黄更为常见。其他试验总体规模较小，结果不一致。
关于补充抗氧化维生素和矿物质在阻止AMD进展方面有效性的证据主要来自美国的一项大型试验。这些发现对其他营养状况不同人群的可推广性尚不清楚。需要在其他人群中进行进一步的大型、精心设计的随机对照试验。不能排除补充剂的长期危害。已发现β-胡萝卜素会增加吸烟者患肺癌的风险；维生素E与血管疾病或糖尿病患者心力衰竭风险增加有关。
