Study: Antioxidants (1990s, 2002, 2004, 2008) & macular degeneration
See more about macular degeneration treatment and information.
An 18-month study found that patient who had macular degeneration and who regularly and daily included antioxidants were two and a half times more likely to see improvement in their vision with standardized testing. They were also four times less likely to experience vision degredation in their weak eye compared to other patients who took the antioxidants less regularly.
Published: Journal of Cataract and Refractive Surgery, Mar 1991.
A study found that patients with age related macular degeneratoin had lower levels of vitamin E, magnesium, zinc, vitamin B6 and folic acid in their daily diet. When patients took antioxidants twice a day their vision improved compared to patients taking a placebo.
Researchers: Richer, et al
Published: Journal of American Optometry Association, January, 1996
A study reported that the antioxidant carotenoids lutein and zeaxanthin protects against AMD by way of antioxidant free radical fighting and screening of damaging UV and blue light. The researchers used Raman spectroscopy to compare the levels of macular pigment in test subjects. The study involved 63 AMD patients and 138 healthy eye patients and found that patients with AMD had 32% less lutein and zeaxanthin (where not taking supplement). Once patients began to consume the carotenoids with 4mg/daily lutein the levels of macular pigments increased substantially.
Researchers: P. Bernstein, University of Utah
Published: Ophthalmology, 2002;109:1780-1878
The researchers looked at macular degeneration research from previous years and found consistant deficiencies in micronutrients in cases of wet macular degeneration. Wet macular degeneration is an advanced form, also known as choroidal neovascularization because new blood vessels form distorting the macular area of the retina.
They evaluated the connection between diet and nutrition and incidence of AMD. Although the initial evidence appeared to be inconsistent, it has become evident that stress in the eye from oxidative damage is an important factor in development of AMD. The researchers conclude that antioxidants can have an important role in slowing or preventing macular degeneration.
Researchers, R. Hogg, et al, Institute of Clinical Science, Belfast
AMD and micronutrient antioxidants, Current Eye Research, December, 2004.
In this study researchers investigated why antioxidants support retinal health. They discovered a connection between several conditions which, combined, cause damage to the retina contributing to macular degeneration. Antioxidants disrupt this process and support the health and integrity of essential photoreceptor cells in the retina.
Synergies occur when separate processes or compound complement each other to enhance the result - beneficial or destructive. The scientists found that the building of a compound identified as A2E reacts with mitochondria within cells (mitochondria are the power source of cellular energy). A2E is a byproduct of cell activity which is not removed naturally by the body.
They found that when A2E exists in cells where oxidative stress due to exposure to damaging UV or blue light is also present that A2E disrupts the action of producing energy in mitochondria. Loss of cellular energy means that waste disposal and photoreceptor maintenance is weakened.
It is a continuing cyle - photoreceptor cells are weakened and die (and are not replaced) and further stress results compounded by the presence of A2E.
Antioxidants fight the resulting damage by protecting the eye from oxidative stress.
Researchers: H. Vollmer-Snarr, et al, University of Brigham Young.
Published: The age lipid A2E and mitochondrial dysfunction synergistically impair phagocytosis by retinal pigment epithelial cells, Journal of Biological Chemistry, November, 2008.
A combination of low levels of antioxidants and exposure to the sun's blue light (as distinguished from ultra violet light) may increase risk of macular degeneration. Blue light alone is not tied to macular degeneration, however researchers have found that there is a consistent and significant connection between with age-related macular degeneration and patients in the lowest quartile nutritional intake of vitamin C, vitamin E, zeaxanthin, and dietary zinc.
The likelihood for neovascular age-related macular degeneration were even more among those patients with the lowest combined antioxidant levels, particularly the combination of vitamin C, zeaxanthin, and vitamin E. The researchers found similar connections in patients with early age-related macular degeneration.
Researchers agree that there is a risk to the eyes from sun exposure, but what interesting is that different wavelengths of light inflict damage on different parts of the eye.
The cornea and lens absorb "invisible" ultraviolet light and are damaged (cataracts) by ultra violet light. The retina absorbs visible light, including blue light, and this study demonstrated that not only can the retina be damaged by blue light, but that blue light exposure combined with low antioxidant levels causes retinal damage, including macular degeneration.
Researchers: Fletcher AE, et al
Published: Sunlight exposure, antioxidants, and age-related macular degeneration, Archives of Ophthalmology, October, 2008