Ekstrak ginkgo biloba untuk degenerasi makula yang berkaitan dengan usia
Abstract
Background
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 (AMD).
Objectives
The objective of this review was to determine the effect of Ginkgo biloba extract on the progression of AMD.
Search methods
We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 10), Ovid MEDLINE, Ovid MEDLINE In‐Process and Other Non‐Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to October 2012), EMBASE (January 1980 to October 2012), Allied and Complementary Medicine Database (AMED) (January 1985 to October 2012), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled‐trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 5 October 2012. We searched the reference lists of identified reports and the Science Citation Index. We also contacted investigators of included studies for additional information.
Selection criteria
All randomised trials in people with AMD where Ginkgo biloba extract had been compared to control were included.
Data collection and analysis
The review author extracted data using a standardised form. The data were verified with the trial investigators. Trial quality was assessed.
Main results
Two published trials were identified that randomised a total of 119 people. In one study conducted in France, 20 people were randomly allocated to Gingko biloba extract EGb 761 80 mg twice daily or placebo. In the other study conducted in Germany, 99 people were randomly allocated to two different doses of Ginkgo biloba extract EGb 761 (240 mg per day and 60 mg per day). Treatment duration in both studies was six months. Both trials reported some positive effects of Ginkgo biloba on vision however their results could not be pooled. Adverse effects and quality of life for people with AMD were not reported.
Authors' conclusions
The question as to whether people with AMD should take Ginkgo biloba extract to prevent progression of the disease has not been answered by research to date. Two small trials have suggested possible benefit of Gingko biloba on vision and further trials are warranted. Ginkgo biloba is widely used in China, Germany, and France. Future trials should be larger, and last longer, in order to provide a more robust measure of the effect of Gingko biloba extract on AMD.
PICO
Plain language summary
Kegunaan ekstrak gingko biloba daripada daun pokok maidenhair, untuk degenerasi makula yang berkaitan dengan usia
Degenerasi makular berkaitan dengan umur (AMD) adalah keadaan yang melibatkan kawasan pusat retina (belakang mata). Keadaan retina boleh merosot dengan umur dan sesetengah orang mendapat penyakit yang boleh menyebabkan kehilangan penglihatan pusat. Gingko biloba, yang diekstrak dari daun pokok maidenhair, digunakan dalam perubatan herba cina untuk merawat pelbagai masalah perubatan, terutamaya masalah peredaran darah. Ekstrak ginkgo biloba mengandungi dua kandungan (flavonoid dan terpenoids) yang mempunyai sifat antioxidan. ia dipercayai dapat mengurangkan perkembangan AMD. Pengarang ulasan mengenalpasti dua kajian terkawal rawak (dengan jumlah 119 peserta); satu di Perancis dan satu di Jerman. Satu kajian membanding Gingko biloba dengan plasebo dan satu membandingkan two dos yang mengandungi ekstrak gingko biloba. Walaupun dua kajian ini melaporkan beberapa kesan positif Ginkgo biloba atas penglihatan, kajian ini adalah kecil dan berjangka pendek. Kesan sampingan dan kualiti hidup tidak dinilai. Kesimpulan keseluruhan ulasan ini bahawa penyelidikan semasa tidak dapat menjawab soalan sama ada Ginkgo biloba dapat memberi manfaat kepada orang yang mengalami AMD. Kajian masa depan perlu melibatkan peserta yang lebih banyak dan juga dilaksanakan lebih lama lagi.
