Mineral zinc linked to blindness

The mineral zinc could play a role in the development of macular degeneration, according to a team of scientists which included researchers from George Mason University, Fairfax, Va. In studying eye tissue samples, the researchers found that deposits, which are hallmarks of age-related macular degeneration (AMD), contain large amounts of zinc. This finding might be particularly important because zinc supplements are given widely to patients to help boost weak immune systems. In addition, a study from the National Eye Institute, Bethesda, Md. (a branch of the National Institutes of Health), found that high doses of zinc supplements, combined with antioxidants, may postpone the progression to blindness.

AMD is a medical condition in which the macula, the place of central vision in the eye, experiences atrophy and, in some cases, bleeding. It is the primary cause of blindness in the elderly in Western society and approximately 13,000,000 Americans suffer from the disease. "Because earlier findings have shown that the zinc contributes to deposit formation in neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease, we were prompted to test the theory that zinc might be involved in deposit formation in AMD," explains Jane Finn, professor of psychology.

"The double-edged sword is that zinc has been found to enhance the immune system, but also could play a role in the advancement of macular degeneration," points out Imre Lengyel of the Institute of Ophthalmology (University College London), who led the collaborative study.

"We now know that we need to take a closer look at the role zinc plays in the development of AMD," states George Mason graduate psychology student Katherine Cano. "We believe this finding will help us unlock other answers to the mystery of treating this disease."

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