Age-Related Macular Degeneration

Many middle-aged and elderly Canadians struggle with age-related macular degeneration of the eyes. It can prevent you from seeing something that’s on the floor, if the object is sitting in your blind spot when you look down. Thankfully, it’s possible to slow visual deterioration through healthy living and supplements.

Leading cause of vision loss

Age-related macular degeneration (AMD) is the leading cause of vision loss among Canadians over 50. More than 1 million Canadians live with this debilitating, progressive eye disease.

The macula is the sensitive part of the retina at the very back of the eye, made of millions of light-sensing cells that create sharp central vision. If the macula becomes damaged, the centre of the visual field can become blurry, distorted, or darkened. This can affect the ability to recognize faces, read and write, drive a car, and perform small tasks that require visual attention, such as sewing.

AMD may progress slowly or rapidly. Sometimes the vision loss occurs gradually over a long period of time, noticed as an increasing area of blurriness in the centre of vision. Blank spots can develop and objects might appear less bright.

In its earliest stages, AMD may have no symptoms at all, despite changes visible on the retina itself. For this reason, it’s important to have regular eye examinations, especially as you get older.

Risk factors

If you have one or more of the following risk factors, it’s even more important that you have your eyes regularly examined by an expert.

Age

Growing older—something we unfortunately can’t avoid—is the top risk factor for AMD. The risk begins to increase after 40; more than 15 percent of Caucasian women over age 80 experience advanced AMD. To ensure early detection, people over 40 are encouraged to get a comprehensive eye exam every two to four years.

Smoking

Cigarette smoking may double or even triple the risk of developing AMD, and this can apply even if smokers quit long ago. AMD rates are rising in Asia, presumably due to the increased smoking rates and effects of environmental pollutants on the eyes.

Exposure to second-hand smoke also increases the risk for AMD. Thankfully, quitting or avoiding smoke exposure still makes a difference. If you haven’t smoked for 20 years, your risk becomes the same as a person who never smoked.

Genetics

Researchers recently discovered a genetic mutation that accounts for approximately 40 percent of AMD cases. If someone in your family has AMD, you are at higher risk. AMD is most commonly found in people of Caucasian origin, although as mentioned earlier rates are rising in other populations due to increased exposure to toxins such as cigarette smoke.

High blood pressure/ heart disease

Elevated blood pressure puts pressure on the eye, not just the larger blood vessels of the body. Hypertension and cardiovascular disease have been shown to be related to the development of the more severe forms of AMD.

Obesity

Being significantly overweight puts more stress on the eye and increases the risk of AMD by increasing inflammation, changing retinal fat composition, and decreasing the circulation of healing nutrients. Research has shown that if you decrease your waist-to-hip ratio by losing abdominal fat, you are less likely to develop AMD.

The three stages of AMD

1) Early AMD

Small deposits called drusen appear in the retina, too small to cause any symptoms. They’re only visible to an eye doctor who uses a special type of lamp and lens to examine the eye.

2) Intermediate AMD

Drusen become larger and pigment changes may also occur in the retina. There may be some vision loss in this stage, but it’s also possible to still have no changes in vision.

3) Late AMD

In this stage, there is now noticeable vision loss from macular damage. There are two different types of Late AMD.

Dry AMD: Due to “geographic atrophy” there is general damage to the light-sensing macular cells and the tissue beneath, resulting in gradual loss of vision.

Wet AMD: Abnormal new blood vessels grow underneath the retina, leaking blood and other fluids and damaging the macula. This can cause quick progression of vision loss.

Some people with AMD never progress to the later stages. Others, unfortunately, develop both the wet and dry forms over time. AMD in one eye increases the risk of developing it in the other, but if you detect this condition early you can reduce your risk of progressive vision loss.

Treatment of AMD

There is no specific treatment for early AMD, but one can focus on improving long-term outcome in the early stages by limiting or eliminating modifiable risk factors and adopting preventative lifestyle habits (see sidebar).

Researchers at the National Eye Institute of the National Institutes of Health found that daily high- dose vitamins and minerals slowed progression of both intermediate AMD and late AMD occurring in just one eye. Two key trials found that daily doses of vitamin C (500 mg), vitamin E (400 IU), zinc oxide (80 mg), copper (2 mg cupric oxide), and the carotenoids lutein (10 mg) and zeaxanthin (2 mg) reduced the risk of developing late AMD by 25 percent or more.

Other types of AMD treatment include drug injections to the eye and photodynamic therapy, which is laser treatment to select areas of the retina paired with medications that can slow the rate of vision loss.

If you have AMD, taking a multivitamin/mineral is a good idea, but it probably doesn’t contain high enough doses for maximal benefits. Some supplement companies have created special products aimed at treating macular degeneration based on this research.

Speak to your eye doctor before starting one of these to confirm that it is the right supplement for you.

6 tips to prevent AMD

Avoid smoking and exposure to second-hand smoke

Smoking is a top risk factor for AMD and is the most easily modifiable.

Monitor your blood pressure

Get your blood pressure checked whenever you see your doctor or test it at the machine at your local pharmacy. If it’s over 130/80 (high normal), see your health care practitioner.

Eat a healthy diet

Eat a diet rich in dark green leafy vegetables. These are rich in the carotenes lutein and zeaxanthin which have been shown to prevent progression of AMD.

Consider taking an AMD-specific supplement

Formulations targeted to treat AMD (containing specific levels of vitamins C and E, zinc, copper, lutein, and zeaxanthin) may play a role in prevention if you’re already at high risk. Check with your health care practitioner before taking.

Maintain a healthy weight

Keeping a slim waistline and losing abdominal fat will make you less likely to develop eye damage leading to AMD.

Regular exercise

Exercise promotes overall physical and cardiovascular health and prevents weight gain.