Macular Degeneration: Symptoms and Risk Factors
It's World Sight Day. Most older adults can expect to encounter some form of vision loss as they enter their 50+ and senior citizen years.
The American Academy of Opthalmology (AAO) tells us that Age-related Macular Degeneration (AMD) is a deterioration or breakdown of the eye's macula (a small area in the retina, which is the light-sensitive tissue lining the back of the eye). Often older people and seniors develop macular degeneration as part of the body's natural aging process. Macular degeneration typically affects the central vision only (side or peripheral vision are usually unaffected).
Macular degeneration is caused either when deposits called drusen form under the retina, or when abnormal blood vessels grow under the retina, and there are two types of macular degeneration:
Dry or Atrophic Macular Degeneration (Non-Neovascular Macular Degeneration)
- 90% of people with macular degeneration have dry macular degeneration, which is caused by the aging and thinning of the tissues of the macula. Vision loss is usually gradual.
Wet (Exudative) Macular Degeneration (Neovascular Macular Degeneration)
- 10% of people with macular degeneration have the more serious form of wet macular degeneration. Wet macular degeneration is caused when abnormal blood vessels grow underneath the retina (a process called choroidal neovascularization or CNV). The abnormal blood vessels may leak fluid or blood, blurring or distorting central vision. Vision loss is usually faster and more noticeable than with dry macular degeneration.
Symptoms of Macular Degeneration
The symptoms of macular degeneration can occur in one or both eyes; typically if it's in one eye, the other eye compensates for it, thus making it difficult for the person to recognize subtle deteriorations in vision in one eye only.
- Blurry vision for either distance and/or reading
- Need for brighter lighting to see up close
- Colors appear less bright or vivid
- Hazy vision
- Difficulty seeing when lighting changes (bright to dim, dim to bright)
- Difficulty recognizing people's faces
- Blank, blurry, dark grey or blank areas in your central vision
- Distortion of vision - ie straight line appears crooked or bent
- Objects/colors may appear different depending on which eye you use
- Loss of central vision
Although you may not be aware that you have macular degeneration until you have a noticeable vision problem, it can also be detected during an eye examination - it's important to have regular eye check ups.
There is no medication or treatment for dry macular degeneration, but vitamin therapy may help. If you have dry macular degeneration, you must monitor your central vision and see your opthalmologist immediately if you notice any changes to prevent further vision loss.
Early detection of wet macular degeneration and treatment can help preserve some of your central vision.
Risk Factors for Macular Degeneration
Aging - Aging is the biggest risk factor for macular degeneration. One large study found that the risk of getting macular degeneration jumps from about 2 percent of middle-aged people in their 50s to nearly 30 percent in people over age 75.
Genetics/Heredity - Approximately 50% of macular degeneration is genetically driven. People with a close family member with macular degeneration have a greater risk of developing macular degeneration themselves.
- Oxidative Stress - Changes to oxygen in the environment can cause our bodies to produce tiny molecules called free radicals, which affect our cells and can damage them. This process is called oxidative stress and is believed to play a significant role in how macular degeneration develops. 1 in 3 Caucasions have genetic changes that make them more prone to damage from oxidative stress, which can lead to macular degeneration.
Inflammation - Inflammation is how our bodies fight off infection, but an overactive immune system and the associated inflammation may be a risk factor for macular degeneration.
Smoking, High Blood Pressure, Abnormal Cholesterol & Obesity - Smoking and high blood pressure are associated with wet macular degeneration, and abnormal cholesterol and obesity are also been linked to it.