AMD was once thought to be an unpreventable part of aging. However, we now know that lifestyle plays a very large role in whether an individual will develop AMD. Analysis from The Human Genome Project, the international scientific research project whose goal was to identify the approximately 20,000 to 25,000 genes in human DNA and determine the sequences of the 3 billion chemical base pairs that make up human DNA, has discovered that three genes cause 90 percent of all cases of AMD. Outside a few major genetic research centers, testing for these genes is not possible. However even a person with all three genes may not get AMD if he or she takes preventive steps; likewise a person with none of these genes may get severe AMD if he or she smokes.
The human eye. Pictured above is a cross-sectional view of a normal, healthy eye. The orange-colored tissue is the sight-forming retina. The dark red spot in the center is the macula where reading and fine vision occur. The macula is very susceptible to aging changes. The whitish circular object on the right side is the optic nerve. The vessels are retina arteries (thinner) and veins (thicker) which nourish the retina and macula.
A clock as viewed by someone with age-related macular degeneration. AMD gradually destroys sharp, central vision, creating what’s called a “central blind spot,” making it difficult to see common objects clearly.
Dry age-related macular degeneration. This is the sight forming tissue on the back of the eye (retina). The yellow spots in the center are called "drusen" and represent spots of age degeneration. The dark pepper like clumps are called "pigmentary changes" and also represent dry AMD. On the right are the optic nerve and the retinal arteries and veins.
Wet age-related macular degeneration.The large, dark area in the center shows blood vessels that have leaked into the eye. This causes extensive scarring and permanent damage to central fine vision.
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