Review of randomized controlled trials on antioxidants for age related macular degeneration (AMD):
A systematic review by Kansagara D et al evaluated seven randomized controlled trials which studied nutritional supplements in patients with AMD. The authors believed that studies with the longest duration and largest group of subjects were able to better identify benefit of the antioxidants because AMD occurs slowly. The smaller studies might have been of insufficient duration or power to detect a treatment effect. This review included the Age Related Eye Disease Study (AREDS) which demonstrated the antioxidants prevented functional vision loss. Additionally, lutein, zeaxanthin, B vitamins, and omega-3 fatty acids have also been reported to decrease AMD progression, while vitamin E and β-carotene where found to increase the risk of late AMD. (7)