Vision and Aging
Age Related Macular Degeneration (AMD)
One million Canadians have some form of AMD, the leading cause of vision loss in Canada. More Canadians have AMD than breast cancer, prostate cancer, Parkinson’s or Alzheimer’s disease combined. AMD is a progressive condition that attacks central vision. People who have AMD may no longer be able to read, drive, or see the faces of their family members. With an aging population, the number of people with the disease is expected to double in the next 25 years.
Prevention & Risk Factors
There is currently no cure for either form of AMD, so prevention is important. The first step is to have your eyes examined in order to know if you have any of the signs of AMD, if you are at risk for developing AMD and we can teach you how be preventative.
Although researchers do not have a definitive cause for AMD, there are a number of factors that may put a person at greater risk for developing the disease.
- Family History
- Age is the greatest risk factor for AMD. An estimated one million Canadians have some form of AMD, and the majority of them are people over the age of 50. Prevalence increases the older you get.
- Gender, estrogen and early menopause – a higher incidence of AMD in women who experience earlier onset of menopause.
- Cigarette smoking – up to four times more likely to develop AMD compared to the general population, and people who smoke and have family history have 144 times the risk of the general population! Exposure to secondhand smoke also contributes to the risk of developing AMD, so if you quit, you’ll also reduce the risk of the people who are close to you.
- High blood pressure and Cardiovascular disease
- Overexposure in sunlight
- Wear sunglasses with a high UV rating
- Cover up with clothing and a hat
- Stay in the shade
- Sun exposure happens even on moderately bright or overcast days, or in the winter
- Diet may alter the risk of developing AMD
- A high consumption of linoleic acid, monounsaturated, polyunsaturated and vegetable fats is associated with double the risk of developing wet AMD
- Red Meat Intake Increases AMD Risk
- Those who ate two or more servings of fish that is high in Omega 3 fatty acids per week had a lower risk for developing AMD
- Other studies have shown that intake of fruits may reduce the risk of AMD, as would diets rich in carotenoids, such as lutein and zeaxanthin, found in dark green leafy vegetables and some berries.
Symptoms can include:
- Blurred or fuzzy vision: An early sign of AMD that, in some cases, might become less apparent under brighter lighting conditions.
- Straight lines appearing wavy or crooked: This symptom is particular to wet AMD and can affect both lines seen in near vision, such as sentences on a page, and those farther away, such as telephone poles and the sides of buildings.
- Decreased contrast sensitivity: People with AMD might have difficulty seeing objects that are the same color as their background, for example, black coffee in a black cup.
- A small, but growing, blind spot in the center of vision: Someone with AMD might be able to see the numbers on the circumference of a clock, but not the hands in the middle.
- Decreased ability to distinguish colors.
- Difficulty seeing at a distance.
AMD is classified into two types: dry AMD (also known as non-exudative) and wet AMD. Dry AMD is more common, accounting for about 90 per cent of AMD cases. It may cause little or no visual symptoms until it is more advanced. There is no cure for AMD, so early diagnosis is key. There are treatments available, but most of them stabilize vision at best. With later diagnosis, AMD treatments may be less effective, or fewer options may be available.
Dry AMD: Dry macular degeneration is diagnosed when yellowish spots called drusen begin to accumulate in the macula. Drusen are believed to be deposits or debris from deteriorating macular tissue. Gradual central vision loss may occur with dry AMD. Vision loss from this form of the disease is usually not as severe as that caused by wet AMD.
People with intermediate AMD have, in one or both eyes, either many medium-sized drusen or one or more large drusen; in these people, there is usually little or no vision loss.
Wet AMD is the more advanced and damaging stage of the disease. In about 10% of cases, dry AMD progresses to wet macular degeneration.
With wet AMD, new blood vessels grow beneath the retina and leak blood and fluid. This leakage causes permanent damage to light-sensitive cells in the retina, causing blind spots or a total loss of central vision. The abnormal blood vessel growth in wet AMD is the body’s misguided attempt to create a new network of blood vessels to supply more nutrients and oxygen to the macula. But the process instead creates scarring and central vision loss.
If you are over 50 or have other risk factors for AMD, you need to be even more proactive about early diagnosis. And if you already have AMD, you still need to be alert to any further changes.
Technology for AMD In Our Office
Digital Retinal Imaging: This test involves taking colour photographs of both the central and peripheral retina, which allows your eye doctor to document the extent and stage of AMD. These images can be compared between visits to follow the progression and/or improvement of the condition.
The Canon CR-2 Plus image is as unique as you fingerprint and provides us with a look at the health of your retina.
The Canon CR-2 Plus Digital Retinal Imaging provides:
- A high resolution image of the retina including the optic nerve, macula and the health of the blood vessels allowing for the confirmation of a healthy eye vs. detection of disease.
- A permanent record for your file, which allows us to view your images each year to look for changes.
- The opportunity for you to view and discuss the image of your eye with your doctor at the time of your exam.
- Special feature Fundus Autofluorescence (FAF) imaging: Helps with Geographic Atrophy, Macular Degeneration, Glaucoma, Diabetic Retinopathy and other conditions that can affect vision may also be identified and monitored using FAF mode. These Metabolic changes at the level of photoreceptor/RPE complex may not be visualized by other routine imaging techniques.
New Genetic Test Available for AMD
A new test called MaculaRisk has recently become available in Canada, and it can teach you about the AMD genes in your genetic makeup. If AMD runs in your family, the test can help you to gauge your chances of developing the condition – and may help you take preventative steps now if it turns out you are more at risk.
The Age-Related Eye Disease Study (AREDS) found that people at high risk of developing advanced stages of AMD, a leading cause of vision loss, lowered their risk by about 25 percent when treated with a high-dose combination of vitamin C, vitamin E, beta-carotene, and zinc. In the same high risk group, which includes people with intermediate AMD, or advanced AMD in one eye but not the other eye , the nutrients reduced the risk of vision loss caused by advanced AMD by about 19 percent.
AREDS 2 Study is currently way and the primary objective is to evaluate the effect of dietary carotenoids—including lutein and zeaxanthin—and/or omega-3 fatty acids—including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)—on the progression to advanced AMD. In an ideal world of healthy living, these dietary compounds would be best obtained through a balanced diet. In reality, however, our food intake is severely deficient of these important nutrients.
For wet AMD, there are several drugs aimed at stopping abnormal blood vessel growth (anti-VEGF) and vision loss from the disease. In some cases, laser treatment of the retina may be recommended. Ask us for details about the latest treatment options for wet AMD.
We evaluate you for AMD when you come in for your eye exam. It is important to have regular checkups because you can have AMD without any noticeable symptoms. If you have dry AMD, talk to Dr. Farrah to see if taking specially formulated vitamin and antioxidant supplements may help to treat your condition.