Sunlight, low anti-oxidant levels likely to damage visionOctober 14th, 2008 - 3:01 pm ICT by IANS
London, Oct 14 (IANS) The combination of low antioxidant levels and exposure to sunlight may damage certain kinds of vision. It is also linked with age-related macular degeneration (AMD).Animal and lab studies suggest that blue light or short-wavelength light may damage the retina and contribute to the development of AMD, which occurs when the area of the retina (macula) responsible for sharp vision deteriorates.
“The retina is vulnerable to the damaging effects of light,” the authors of the study wrote. “While wavelengths in the UV (ultra violet) radiation range are largely absorbed by the cornea and lens, the retina is exposed to visible light, including blue light”.
Antioxidant enzymes - including vitamins C and E, the carotenoids (lutein and zeaxanthin) and zinc - may protect against the harmful effects of blue light on the retina, according to a release of American Medical Assocation.
Astrid E. Fletcher of the London School of Hygiene and Tropical Medicine and colleagues measured levels of these nutrients in the blood of 4,753 older adults (average age 73.2) who were part of the European Eye Study.
Participants also were interviewed about their lifetime sunlight exposure and had photographs taken of their retinas to detect AMD.
Of the 4,400 participants with complete information available, 2,117 did not have AMD, 101 had neovascular (advanced, involving the formation of new blood vessels) AMD and 2,182 had early-stage AMD.
Overall, there was no association between blue light exposure and early AMD. However, blue light exposure was associated with neovascular AMD in the one-fourth of individuals with lowest antioxidant levels.
The study was published in the October issue of Archives of Ophthalmology.