Age Related Macular Degeneration

Cindy Smith was driving down a country road in Kansas a couple of years ago when she noticed something odd. The telephone poles all had kinks in them.

“I thought, ‘Wow, what’s all that about?'” says Smith, a marketing consultant. “They all had distinctive bends in the middle.”

She pulled off the road and called a friend. “I knew something bad was happening,” she says. “It was nothing I could ignore.”

Her friend referred Smith to an eye specialists. Smith made an appointment and was diagnosed as having age-related macular degeneration.

AMD is a disease that causes significant vision loss in 1.75 million Americans. More than 10 million suffer from various forms of this potentially sight-stealing disease, more than glaucoma and cataracts combined, according to the American Macular Degeneration Foundation.

By 2020, as the population ages, that number is expected to double.

In addition, says Dr. Karl of the Retina Foundation of the Southwest, “more severe forms will be more of an issue.”

“People who are in their 70s and 80s are extremely active,” says Dr. Karl, head of the foundation’s Harrington Molecular Laboratory and an ophthalmologist with Texas Retina Associates. “If you had even a relatively small disturbance in vision, that could be extremely devastating in terms of what you’re used to doing.”

Some vision disturbances, such as difficulty reading small print, are inherent with aging. The lenses of our eyes change and can no longer focus close up, so we rely on reading glasses.

Macular degeneration goes beyond the normal aging process. It affects the center of the retina; specifically, the 0.1 percent that’s responsible for 99.9 percent of our fine vision, Csaky says.

“Unfortunately,” Csaky says, “the central part is what gives you quality of life, the ability to read, drive, play golf, to discern faces.”

He uses the analogy of a camera to explain the difference between normal eye aging and macular degeneration.

“The lens of the eye is like the lens of a camera,” he says. “Cataracts are when the lens of the camera gets cloudy and the picture gets fuzzy. The solution? Change your lens, which is what cataract surgery is.

“In macular degeneration, your film has gotten old. We can change lenses, put in a special lens, and still have a bad picture because the film is starting to decay.”

Macular degeneration has no cure, but those involved in studying and treating it point out glimmers of hope:

Though it may cause legal blindness, rendering some victims unable to drive or read, it won’t cause total blindness.

Most kinds never progress past the initial stage. Diagnosis is not “a death sentence for vision,” Csaky says.

Treatments can slow down and sometimes reverse the more severe cases of the condition.

Diagnostic tools can catch it in its early stages.

To check for it, “We dilate your eyes, use a lens and look for yellow spots (drusen) or pigmentation changes or bleeding,” says Dr. Yuguang He, associate professor of ophthalmology at the University of Texas Southwestern Medical Center and a specialist in age-related macular degeneration. “It’s not like it takes a blood test or X-ray to diagnose. We just look at it.”

The sooner it’s found, the better, he says. “There is a window in which we can do treatments.”

Most treatments are geared toward the more advanced form called wet macular degeneration. The early stage is called dry, which can progress to late-severe dry and sometimes lead to wet.

Progression from the dry form to wet can be rapid. Tyler went to a doctor when she first had symptoms, so he was able to diagnose the disease early. Thus, she’s been able to receive a relatively new and often successful treatment: a monthly shot directly into each of her eyes.

“It’s psychologically and emotionally very draining,” says Tyler, whose father has the dry variety of the disease.

The shot, explains Csaky, her doctor, inhibits a protein responsible for blood vessels growing and bleeding under the retina.

“We’re not curing the disease,” he says. “We’re inhibiting, with a drug, a protein that’s constantly being made, and with the injection it disappears for four to six weeks. The blood vessels are still there in a dormant state. If you don’t treat them, they start to grow back.”

It’s not comfortable, but patients tolerate it well, he says, though occasionally “we have a loved one faint who’s watching. We use a topical anesthetic and a very, very small needle.”

Although there is no surefire way to prevent the disease, studies have shown that eating fish two or more times per week helps reduce the risk, he says. “I take fish oil. I’m 54 years old and take it not only to prevent AMD but also to protect my heart, help my cholesterol. I tell patients, something good for your heart has to be good for your eyes.”

He also points out the Age-Related Eye Disease study of the National Eye Institution. Participants took large quantities of vitamins A and C, as well as zinc, copper and beta carotene. The regimen neither prevents the disease nor, in the study, did it have any effect on the dry form, but it “slowed the progression of the wet variety by 20 percent,” he says.

Tyler, who declined to give her age, manages her ailment as best she can, getting injections and participating in a study. She is constantly aware of her surroundings, on the lookout for any line in a grid that appears curvy or wavy. She checks the spindles on her staircase, “whatever’s around me,” for possible distortion.

“It was never even in my mind, as driven and focused as I am in my career, that I wouldn’t be responsive to it,” she says. “It’s your vision for heaven’s sake. How scary is that?

“You can work with it and make it a positive thing, or it can devastate you. You make these choices in life. What am I going to do about it? Is it going to define me, or am I going to help define it?”

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Age-related macular degeneration (AMD) is the No. 1 cause of irreversible vision loss among senior citizens, according to the Retina Foundation of the Southwest. Some risk factors:

Caucasians are more likely to contract AMD than other races.

“If you’re a Caucasian older than 65, there’s a 20 percent chance you’ll get it,” says Dr. Yuguang He, associate professor of ophthalmology at UT Southwestern Medical Center. “If you’re Chinese or Japanese, less than 5 percent. African-Americans have it much less than Caucasians.”

Yet, “as the Japanese adopted our diet, their incidence has gone up,” says Dr. Karl Csaky of the Retina Foundation of the Southwest and Texas Retina Associates.

Smoking increases incidence.

“Cigarette smokers are 20 times more likely to develop AMD than nonsmokers,” he says. “The chances are very, very high.”

If one eye is affected, the other eye will be, too.

It’s important to periodically cover up the eye that has it to see whether the other eye is seeing distortions, too.

Genetics play a factor.

“If your parents have it, there’s an increased risk you’ll get it, but it’s not a guarantee,” he says. “We’re still struggling with the practical implications of these genetic associations other than scaring people.”

Nutrition’s Potential to Save Sight

While 20/20 vision is a symbol of visual acuity, between now and the year 2020, more and more people will experience some extent of vision loss due to age-related macular degeneration (AMD) and other sight-robbing diseases.
Now, Agricultural Research Service (ARS)-funded scientists at the Laboratory for Nutrition and Vision Research are finding that healthy eating can reduce not only health care costs, but also the decline of quality of life due to these diseases. The laboratory, directed by Allen Taylor, is part of the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston, Mass.
One study indicated that regularly consuming a combination of protective nutrients and a low-glycemic-index, or “slow carb,” diet provided an AMD protective effect. A food’s glycemic index is an indicator of how fast the carbohydrate it contains will spike blood sugar levels. The macula is a 3-millimeter-wide yellow spot near the center of the retina responsible for the central field of vision.
For the study, the researchers analyzed dietary intake and other data from more than 4,000 men and women, aged 55 to 80, who had participated in the long-term Age-Related Eye Disease Study, or AREDS. Led by Chung-Jung Chiu, the researchers ranked intake of each of several nutrients consumed during the AREDS study, then calculated a compound score to gauge their combined dietary effect on the risk of AMD. The scoring system allowed them to evaluate associations between individual–and combined–dietary nutrients.
The nutrients that were found to be most protective in combination with the low-glycemic-index diet were vitamins C and E, zinc, lutein, zeaxanthin, and the omega-3 fatty acids known as DHA and EPA. The 2009 study was published in Ophthalmology.
Read more about this and other research related to improving health through nutrition in the July 2010 issue of Agricultural Research magazine, available online at: http://www.ars.usda.gov/is/AR/archive/Jul10/sight0710.htm.
ARS is the principal intramural scientific research agency of the U.S. Department of Agriculture (USDA).

Good Fats Reduce the Risk of Macular Degeneration

A study was reported in the Archives of Ophthalmology that revealed a protective effect of omega-3 fatty acids and monounsaturated fats against age-related macular degeneration. Dr. Jennifer Tan and her colleagues determined that men and women who consume at least one serving of fish per week had a 31% lower risk of developing macular degeneration compared to those who consumed less. Eating nuts, olive oil, and other good fats helped even more.

A follow-up study reported in the same journal, showed that those individuals who had a high intake of trans fats were at a significantly higher risk of developing macular degeneration. In my Healthy for Life Program, I strongly promote decreasing your intake of bad fats (saturated fats), eliminating trans fats, and increasing your intake of the good fats (monounsaturated and omega-3 fats). All fats are not bad. It is the types of fats you consume that are the key.

Fish oil tablets are readily available, but many are contaminated with mercury. Insure you only take a pharmaceutical grade fish oil.

Antioxidant supplement shows potential against AMD

A combination of antioxidant pigments and vitamins may slow down sight loss in elderly people, according to researchers from Queen’s University, Belfast.

The study used a commercial supplement containing lutein, zeaxanthin, vitamins C and E, and zinc. The supplement is available from Bausch and Lomb, the company that holds the patent for the AREDS supplement.
According to findings presented at ARVO 2009, in Florida, the combination supplement slowed down the progression of early age-related macular degeneration (AMD) to late AMD.
AMD is a degenerative retinal disease that causes central vision loss and leaves only peripheral vision, and the leading cause of legal blindness for people over 55 years of age in the Western world, according to AMD Alliance International.
Results of the Carotenoids in Age-Related Maculopathy (CARMA) study indicated that intake of high levels of lutein and zeaxanthin preserved the macular pigments. On the other hand, the macular pigments of participants in a placebo group declined steadily.
“These findings are important because this is the first randomised controlled clinical trial to document a beneficial effect through improved function and maintained macular pigments,” said the study’s coordinator, Professor Usha Chakravarthy, from Queen’s Centre of Vision and Vascular Science (CVVS).
“Further research is needed to confirm these findings and to identify the numbers needed to treat to prevent 1 case from progressing from early to late AMD,” she added.
According to the study protocol, published last year in Ophthalmic Epidemiology (Vol. 15, pp. 389-401), the Carotenoids in Age-Related Maculopathy (CARMA) study is a randomized, placebo-controlled, double-blind clinical trial involving 433 participants with early AMD features in at least one eye or any level of AMD in one eye with late AMD in the other eye.
“The aim of the CARMA Study is to investigate whether lutein and zeaxanthin, in combination with co-antioxidants (vitamin C, E, and zinc), has a beneficial effect on visual function and/or prevention of progression from early to late stages of disease,” state the researchers in Ophthalmic Epidemiology.
Study is ongoing, but it appears the combination of nutrients does indeed show potential against AMD.
“Late AMD causes severe sight loss and has a huge economic impact both in terms of the effects of sight loss itself and in terms of the expensive treatments that are needed to deal with the condition,” added Prof Chakravarthy.
“We wanted to carry out the study as prevention of progression to late AMD can result in a reduced financial and societal burden.”
The study was funded by Dr Mann Pharma and Bausch and Lomb and sponsored by the Belfast Health and Social Care Trust.