AUGUSTA, Ga. - The most common and under-diagnosed genetic disease in humans just may be a cause of the worst form of macular degeneration, Medical College of Georgia researchers report.
They are pursuing a link between hemochromatosis, which results in iron overload, and the wet form of macular degeneration, the leading cause of blindness in people 60 and older. They suspect that too much iron, known to wreak cumulative havoc on the body's organs, hastens normal aging of the eyes.
If they are correct, avoiding the most severe consequences of a disease that robs the central vision could be as simple as donating blood a couple times annually to reduce iron levels, said Dr. Vadivel Ganapathy, chairman of the MCG School of Medicine Department of Biochemistry and Molecular Biology.
A $1.5 million grant from the National Eye Institute is enabling the MCG scientists to define the impact of hemochromatosis on the eye's form and function. Support from MCG's Vision Discovery Institute is enabling screening for its causative genetic mutation in the blood of healthy individuals and those with macular degeneration.
"If this is a predisposing risk for macular degeneration, we have a very useful tool for screening patients," said Dr. Julian Nussbaum, a retinal specialist who chairs the School of Medicine's Department of Ophthalmology and co-directs MCG's Vision Discovery Institute. "We can give patients information right off the bat that may help them."
While linking iron overload to eye disease may seem odd, they have in common the result of too much of a good thing. The eyes need light to see and the body needs iron to deliver oxygen but the price of both is increased oxidative stress, Ganapathy said. "You need oxygen and you need iron to make this bad molecule," he said of oxygen radicals that can destroy tissue down to the DNA.
Light alone takes a slow toll on the retina, which converts it into electrical impuls
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Medical College of Georgia