Macular degeneration, often called AMD or ARMD (age-related macular degeneration) affects an estimated one million Canadians and is most common in people over 50. Vision loss from macular degeneration is a growing problem because of an aging population. AMD can be devastating, but with proper support sufferers can livesatisfying and independent lives.
AMD occurs with degeneration of the macula, which is the part of the retina responsible for the sharp, central vision needed to read or drive. Because the macula primarily is affected in AMD, central vision loss may occur.
Dry Macular Degeneration
- Dry AMD is more common and occurs because the tissue beneath the retina thins as we age. It progresses over a matter of years.
- Dry AMD is diagnosed when yellowish spots (know as drusen) begin to accumulate typically around the macula from deposits or debris from deteriorating tissue. Gradual central visual loss may occur, but it is not as severe as wet AMD.
Wet Macular Degeneration
Dry AMD progresses to this more advanced and damaging form of the eye disease in about 10 percent of cases. With wet AMD, new blood vessels grow beneath the retina and leak blood and fluid. This leakage causes permanent damage to light-sensitive retinal cells which die off and create blind spots in central vision.
Wet AMD falls into two categories:
- Classic: When blood vessel growth and scarring have very clear, delineated outlines observable beneath the retina, this type of wet AMD is known as classic choroidal neovascularization (CNV), and usually produces more severe vision loss.
- Occult: New blood vessel growth beneath the retina is not as pronounced, and leakage is less evident in the occult CNV form of wet macular degeneration, which typically produces less severe vision loss.
Controllable Risk Factors
Smoking: This is a major risk factor. A British study found about 25% of AMD cases causing severe vision loss to be directly associated with smoking. Another study showed that people living with a smoker doubled their chances of developing AMD.
Over exposure to the sun : Wear a hat when outside and sunglasses with at least 98% UV protection.
High Blood Pressure
Obesity and Inactivity: Overweight patients with AMD had more than double the risk of developing advanced forms of the disease compared with people of normal body weight. In the same study, those who performed vigorous activity at least three times weekly reduced their risk of developing advanced AMD, compared with inactive patients. Make sure you maintain a low-fat diet and a healthy weight.
Drug Side Effects Some cases of AMD can be induced from the side effects of toxic drugs. Make sure to tell your eye doctor if you are taking any medications or drugs for other conditions you may have.
- Blurred or fuzzy vision
- Straight lines that appear wavy or crooked
- Decreased contrast or colour sensitivity
- Difficulty seeing at a distance
- A small but growing blind spot in the center of vision
If you would like more information on diabetic retinopathy, talk to your eyecare professional or check out the following online resources available to you.
- Canadian Opthalmological Society
- Canadian Association of Optometrists