Contacts That Won't Bug You
Sydney Morning Herald
Thursday July 31, 2008
FOR many contact lens wearers, the red-eye special is not about an overnight flight from Perth, but the gritty, inflamed effect of something gone wrong while you were sleeping.
Most infections are caused by bacteria on the surface of the lens. In its first clinical trial, selenium-coated contact lenses will be tested for three months by 30 people in Australia and 100 in India at the LV Prasad Eye Institute in Hyderabad.The first phase - where it is tested for its safety on humans - has been completed, and the lenses were shown to be safe for the 30 people who participated, Professor Mark Willcox, of the University of NSW, says.Willcox says eye infection is not common; for those who sleep with their lenses in overnight, the rate is one infection in 500, and for those who remove lenses overnight and disinfect them, it is one in 2500. But if not treated rapidly, it may cause permanent loss of sight.More common is inflammation, occurring in one in 20 overnight wearers and one in 100 for those who remove lenses."We need selenium for normal metabolic function, but there is something else about it: it produces oxygen radicals," Willcox says. "These are very reactive oxygen species, that oxidise most things very effectively, and bacteria are very susceptible." The coating was developed by a private institute, Selenium, at the Texas Technology University, and the trial is a joint venture with the Institute for Eye Research, a private organisation based at the University of NSW.Willcox, a professor of optometry, a microbiologist and the chief scientific officer with the institute, is no stranger to clinical trials. As a student in Britain, he subsidised his living expenses as a paid participant in trials - a practice banned here.
© 2008 Sydney Morning Herald
