Vision Quest - the sun can damage your eyes protect...
|Vision Quest - help fight eye problems.||Darrell Miller||06/18/05|
June 18, 2005 08:34 AM
Author: Darrell Miller (firstname.lastname@example.org)
Subject: Vision Quest - help fight eye problems.
Vision Quest by Phyllis D. Light, RH Energy Times, February 11, 2004
Since your eyes are in constant use every day, exposed to the damaging energy of sunlight and pollutants that waft through the air, these delicate orbs are often in danger of wearing out.
To keep this vital part of your anatomy functioning as you age, you have to feed and care for your eyes properly. Otherwise, you are in real danger of losing your vision and independence.
Your vision may be in danger. Experts estimate that 8 million Americans over the age of 55 are at serious risk of blindness linked to a condition called age-related macular degeneration (AMD). AMD can wipe out your central vision and is the primary cause of blindness in Western society.
While AMD causes no pain, it blurs the sharp, central vision necessary for driving, reading and other activities where you need to see either up close or straight ahead. During AMD, the macula, the part of the eye that allows you to pick out fine detail, is destroyed. The macula sits at the center of your retina, the nerve center at the back of your eye that senses light and sends optic signals to the brain.
Age is not the only risk factor for AMD. Scientists have isolated a genetic defect that can lead to some forms of macular degeneration (Nature Genetics 2001; 27:89-93). Smoking and excessive exposure to sunlight are other hazards best avoided if you want to save your sight.
In many cases, AMD progresses so slowly that victims of this condition don't even notice that their vision is deteriorating until much of it is irrevocably gone.
Dry and Wet AMD
Wet AMD occurs when blood vessels in back of the retina start to overgrow and leak blood. As this occurs, blood and other fluids push on the macula and quickly damage its sensitive nerve endings. When wet AMD occurs, you lose your central vision rapidly. If straight lines appear wavy to you, you may be suffering from wet AMD. If you notice this or other unusual vision changes, contact an eye care specialist as soon as possible. You need what is called a comprehensive dilated eye exam that can uncover signs of AMD.
Dry AMD strikes the eye when light-sensitive cells in the macula slowly deteriorate, gradually blurring central vision in the affected eye. As dry AMD progresses, a blurry spot in the center of your vision may appear. Eventually, as more of the macula becomes dysfunctional, the central vision in the eye can gradually disappear.
The most common sign of dry AMD is slightly blurry vision. This can make it hard to recognize faces and also make it harder to read without very bright light. Dry AMD generally attacks both eyes, but vision can be lost in one eye while the other eye stays normal. In the early stages of dry AMD, drusen, yellow deposits that gather under the retina, may form. Dry AMD progresses in three stages:
Vitamins and Minerals for AMD
Fortunately, scientists have found ways to combat AMD: An analysis of a study called the national Age-Related Eye Disease Study (AREDS) shows that more than 300,000 Americans could avoid losing their sight to AMD if they took daily supplements of antioxidant nutrients and zinc.
This conclusion, reached by scientists at Johns Hopkins' Wilmer Eye Institute, is based on research involving more than 4,500 adults suffering various stages of AMD. The study demonstrated that people who already had some AMD could lower their risk of the more advanced form of this condition by 25% when they took vitamin C, natural vitamin E and beta carotene along with zinc. Those suffering from advanced AMD lowered their chances of losing vision by about 19%. (Supplements did not affect the risk of cataracts or the chances of some vision loss for people in the early stages of AMD.)
" Without treatment to reduce their risk, we estimate that 1.3 million adults would develop the advanced stage of AMD," says Neil M. Bressler, MD, professor of ophthalmology at Johns Hopkins and author of the current study, published in Archives of Ophthalmology (11/03).
According to Dr. Bressler and the other researchers, people who now have intermediate AMD (some vision loss) in one eye have about a 1 in 16 chance of having their vision deteriorate until they have advanced AMD. They also calculate that about 1 in 4 of those with intermediate AMD in both eyes and 43% of those with advanced AMD in one eye will develop advanced AMD in five years without treatment.
In their view, older people at risk of AMD blindness should take daily supplements of 500 milligrams of vitamin C, 400 milligrams of natural vitamin E, 15 milligrams of beta carotene, 80 milligrams of zinc as zinc oxide and 2 milligrams of copper as cupric oxide. Evidence also exists that a diet which is high in fat can cause AMD to progress to an advanced stage. The exceptions: The healthy fats found in fish and nuts (Archives of Ophthalmology 2003; 121:1728-37).
Oddly enough, some of the same pigments that color vegetables and other foods also color your eyes. And scientists believe that those pigments, which are classified as carotenoids, help protect the eyes by helping them fight off the negative effects of caustic molecules called free radicals. Free radicals are formed when the energy from sunlight strikes the eyes and disrupts the composition of natural chemicals found there.
When scientists compared healthy eyes with eyes suffering from AMD, they found that AMD eyes contained lower levels of lutein and zeaxanthin, carotenoid pigments contained in egg yolk, spinach, broccoli and other dark green vegetables (Ophthalmology 2003; 109:1780). Furthermore, they found that levels of these chemicals generally decline as you grow older.
" This research is a major step toward large-scale clinical studies to prove the extent to which lutein and zeaxanthin protect against age-related macular degeneration," says Paul S. Bernstein, MD, PhD, at the University of Utah School of Medicine at Salt Lake. "We know that these carotenoids are specifically concentrated in the macula of the human eye."
Dr. Bernstein adds that, as you age, taking supplements containing lutein and other antioxidants may lower your AMD risk. In his investigation, people with AMD who did not take lutein had one-third less lutein in their eyes than older people whose vision was normal.
Another eyesight hazard is cataracts, in which the eye's lens-the part that focuses incoming light onto the retina-becomes cloudy. Cataracts form when the proteins found in the normally clear lens become damaged; signs include progressively blurred vision (especially outdoors), focusing problems, seeing streaks of light from headlights and stoplights, and colors that look faded.
Cataract is the leading cause of blindness worldwide, according to the World Health Organization. One of every six Americans 40 and older suffers from some degree of cataract; it affects half of all Americans who reach age 80. Nuclear cataracts, the most common form of this disorder, develop in the center of the lens and tend to grow slowly. Cataracts may also develop at the back of the lens; this form is linked to eye trauma and long-term use of certain medications, including steroids.
Like AMD, cataracts become more common as people age. Up to 40% of individuals between the ages of 75 and 85 have them, compared with only 5% to 10% of those folks under the age of 65. And like AMD, sunlight exposure and smoking increase the risk of developing cataracts, as does the presence of diabetes.
Lutein and zeaxanthin, the carotenoids that are so plentiful in the macula, are also found in the lens (although in lower concentrations), leading many researchers to believe that these nutrients may help drop your risk of cataract development. Early studies indicate that an increased intake of lutein and zeaxanthin reduces one's chances of needing cataract surgery, the most common surgery in the United States (American Journal of Clinical Nutrition 1999; 70(4):509-16; 517-24).
Antioxidants and the Lens
Scientists believe that free-radical damage is a leading cause of cataracts, and so it isn't surprising that antioxidants have proved useful in preventing this problem.
Almost 500 women filled out diet questionnaires as part of a very large research effort called the Nurses' Health Study; those who had taken vitamin C supplements for 10 years or longer enjoyed the lowest rates of nuclear cataracts (Archives of Ophthalmology 2001; 119:1009-19).
So the answer to lowering your risk of eye problems is clear, whether you are already in your mature years or plan to be someday: Lead a healthy, eye-friendly lifestyle, eating a diet filled with colorful fruits and vegetables. Take frequent walks and jogs around the block.
And yes, when you kick back and take your just-as-frequent doses of antioxidant supplements, you're allowed to take your sunglasses off and see the world clearly.