Ginkgo biloba extract for age-related macular degeneration

Abstract

Ginkgo is used in the treatment of peripheral vascular disease and 'cerebral insufficiency'. It is thought to have several potential mechanisms of action including increased blood flow, platelet activating factor antagonism and prevention of membrane damage caused by free radicals. Vascular factors and oxidative damage are thought to be two potential mechanisms in the pathology of age-related macular degeneration. The objective of this review is to determine the effect of Ginkgo biloba extract on the progression of age-related macular degeneration. The Cochrane Eyes and Vision Group specialised register, the Cochrane Controlled Trials Register - Central, MEDLINE, reference lists of identified trial reports, and the Science Citation Index were searched. The reviewer contacted Investigators of included studies for additional information. The most recent searches were performed in February 2000. All randomised trials where Ginkgo biloba extract had been compared to control in people with age-related macular degeneration were included. The reviewer extracted data using a standardised form. The data were verified with the trial investigator. One published trial was identified. Although a beneficial effect was observed, as only 20 people were enrolled in the trial, and assessment of outcome was not masked, its results must be considered equivocal. Adverse effects and quality of life for people with age-related macular degeneration have not been addressed. One unpublished trial is awaiting translation and assessment. The question as to whether people with age-related macular degeneration should take Ginkgo biloba extract to prevent progression of the disease has not been answered by research to date.