Age-related macular degeneration, or AMD, is the leading cause of vision loss in people over 55, affecting more than 10 million people in the U.S. alone. Because older people represent an increasingly larger percentage of the general population, vision loss from macular degeneration is a growing problem. AMD is a degenerative disease that affects an area of the eye known as the macula. Located at the center of the retina, which is the back lining inside the eyes, the macula is roughly the size of a letter “O”, size 12 font. It’s what gives us the detailed vision we need to do things like reading, driving, recognizing faces, and other things that require sharp, high-definition, straight-ahead vision.  AMD often starts in one eye and after several years develops in the other.

There are two types of AMD: wet AMD and dry AMD

• Wet AMD occurs when delicate, abnormal blood vessels form under the retina where they don’t belong. These fragile vessels leak blood and fluid beneath the retina, causing it to distort or scar. This is the reason for loss of sharp vision in people with wet AMD. Wet AMD progresses far more rapidly than dry AMD, with more severe effects — potentially including complete central vision loss. Fortunately, wet AMD occurs in only about 10% of cases.

• The other 90% of cases are people living with dry AMD, which occurs when the retinal pigment epithelium (RPE) begins to thin. Dry AMD is also associated with tiny yellow deposits called drusen that form beneath the retina. It has been suggested that, as these drusen accumulate, they may lift the cells that transport nutrients to the retina away from their blood supply, impairing the transport of vital substances into and waste out of the central macular area of the retina. The result can be the loss of central vision. However, in most cases, people with dry AMD experience a less severe degree of vision loss in the beginning, and it develops slowly — over a period of years. 

In most cases, the loss of vision that comes from AMD is gradual. In the early stages, there is little or no vision loss, but over time images become blurry or distorted and a dark area ultimately appears in the center of your field of vision. This can make activities like driving, reading, or even playing cards increasingly difficult. The emotional effects of AMD can be just as serious. Feelings of helplessness, anger, and depression are common when people living with AMD are learning to deal with the disease. But, by staying informed about the latest advances in treatment and support services, you can take back control of your life.

AGE-RELATED EYE DISEASE STUDY 2 (AREDS2)

AREDS stands for Age-Related Eye Disease Study, and as we live longer and longer, the results will be of interest to all of us. 

The National Eye Institute (NEI), of the National Institutes of Health, conducted the 10-year AREDS study in the early 1990’s to test the effectiveness of a high-potency vitamin and mineral supplement on eye health and vision. It is the most exhaustive clinical study to date on AMD. 

The results of this study were released five years ago. The study found that high-dose antioxidant vitamins and minerals (vitamins C and E, beta-carotene, zinc, and copper), taken by mouth, reduced the risk of progression to advanced AMD by 25 percent, and the risk of moderate vision loss by 19 percent. 

Phase two of the AREDS study began in 2006 to evaluate whether similar protective effects against AMD may be associated with other nutrients such as omega -3-fatty acids (found in cold water fish), and lutein and zeaxanthin (found in green, leafy vegetables.) Omega-3 fatty acids, lutein, and zeaxanthin, were not included in the original study.

About lutein and zeaxanthin.

Interestingly, our macular pigment is composed primarily of lutein and zeaxanthin.

 These two compounds are found in large amounts in the lens and retina of our eyes. Here they function as antioxidants to potentially help protect our eyes from damage caused by unstable atoms known as free radicals, which can interact with and break down healthy tissue. 

Lutein and zeaxanthin may also help to protect our eyes by filtering high-energy blue light. By filtering blue light, the pigment protects underlying cell layers from potential light damage. 

During the studies, dietary lutein and zeaxanthin intake at baseline was inversely associated with wet AMD. 

About Omega-3 Long-chain Polyunsaturated Fatty Acids

The second dietary factor that was found to be associated with a decreased risk of wet AMD in AREDS was omega-3 long-chain polyunsaturated fatty acids (LCPUFAs), which come from fish. Dietary total omega-3 LCPUFA intake was inversely associated with wet AMD, as was docosahexaenoic acid, (DHA), a component of omega-3 LCPUFA. Higher fish consumption either broiled or baked, was inversely associated with wet AMD. Dietary intake of arachidonic acid (found mostly in red meat) was directly associated with increased wet AMD prevalence.

Both of these dietary factors have been reported in previously published reports of nutrition and AMD.

Other Studies:

The Archives of Ophtjalmology reported findings in 2001 that consumption of omega-3 fatty acids also had a protective effect against AMD. Meanwhile, consumption of omega-6 fatty acids, present in vegetable oils, was associated with an increased risk of developing AMD.

Who Will Most Likely Get Macular Degeneration?

• Family history of macular degeneration.
• Smoking (even if you smoked and quit).
• Low macular pigment. Low levels of macular pigment (important photoprotectant against damaging UVA and UVB rays) are associated with increased risk.
• Having light skin and/or light eyes.
• Having had unprotected exposure to the sun.
• Being overweight. Studies found that overweight patients had more than double the risk of developing advanced forms of AMD compared to people of normal body weight.
• Gender - females are at more risk.
• Diet deficient in foods containing zeaxanthin & lutein.
• Low levels of macular pigment (important photoprotectant against damaging UVA and UVB rays) are associated with increased risk.

What Can You Do?

• Discuss risk factors with your doctor.
• You can’t change heredity, but you can stop smoking and lose weight.
• Protect your eyes from UV rays by having UV blocking
• properties in your glasses.

For those at risk of age-related vision loss:

Nutrition plays an important role in the health of your eyes. Emerging science suggests that proper nutrition is critical to maintaining eye health, whatever your age. Unfortunately,  most Americans don't get the nutrition they need through diet alone so adding a vitamin and mineral supplement to your diet may be helpful in protecting your eyes as you age.

Risks to smokers:

Note that beta-carotene supplementation is not recommended for smokers or ex-smokers, because of an association with increased risk of lung cancer. This risk is associated only with the beta-carotene supplement, and not with natural dietary sources. You should consult your physician before attempting any kind of high-dose supplementation.

Currently, the AREDS formulation is not recommended for smokers.

In Summary:

In addition to taking vitamin and mineral supplements designed for eye health, make sure you schedule regular eye exams with your doctor, protect your eyes from UV radiation, and stop smoking if you currently do. These are important steps you can take to maintain healthy eyes throughout your life. Encourage your friends and family members to protect their eye health too.