By Chong Wee Hou, Optometrist, International Eye Cataract Retina Centre, Singapore
Ms Chan Hsiao Lan Stacy, Associate Lecturer in Parkway College for the BSc(Hon) Optometry & Clinical Practice programme in collaboration with Aston University, was a guest speaker at the Singapore Primary Eye Care Symposium (SPECS) 2018 held in One Farrer Hotel on 18-19 July 2018. Her talk on “Nutrition and Eye” focused on the function of antioxidants in the eye and how antioxidant supplements can benefit the eye.
Ms Chan explained how oxidative damage in the eye are caused by free radicals which are natural by-products of the body’s biochemical reactions. These free radicals are highly reactive and unstable, and can damage cells in the body.
Besides an enzyme system that scavenges free radicals in the eye, micronutrients such as vitamin E, vitamin C and beta-carotene are antioxidants that can also mop up free radicals. However, since the human body is unable to manufacture these micronutrients, they must be supplemented in the diet. Most plant-based foods contain antioxidants – for example, broccoli and peppers contain vitamin A, while red cabbage and citrus fruits contain vitamin C.
The Age-Related Eye Disease Study (AREDS) is a well-known double-blind randomised controlled trial that showed that a daily intake of vitamin and mineral supplements can decrease the risk of progression of age-related macular degeneration (AMD) to a more advanced stage. The AREDS formula containing vitamin C, vitamin E, beta-carotene, zinc and copper reduces the risk of progression of intermediate AMD to advanced AMD by 25% over five years, and cut moderate vision loss for those at high risk of geographic AMD or choroidal neovascular membrane by 19% over five years.
Although a few studies have shown that taking vitamin supplements may help improve certain ocular conditions such as dry eye syndrome, cataract and glaucoma, most clinical studies on antioxidant supplements have not found substantial health benefits. Ms Chan also cautioned against taking too much supplements as they may cause adverse effects on certain patients. She also suggested including more vegetables and fruits in the diet as part of a healthy lifestyle.