Macular degeneration (MD) is a disease of the central retina (called the macula) that affects central vision and is the leading cause of vision loss among people over age 65. The macula is responsible for high resolution central detail. If you concentrate on the vision away from your central focus, you will notice it is not nearly as clear as the image in front of you. This is because our macula has a different structure to give us clearest detail in the very centre of our vision. Because it affects only central vision, macular degeneration does not cause total blindness, however it can make most daily activities like driving and reading difficult or impossible.
The exact cause of macular degeneration is still not understood, but it is thought to be associated with artherosclerotic changes in the tiny blood vessels that nourish the macula, compromising the blood flow to this part of the retina.Age plays a role in the disease. For this reason, it is was originally referred to as age-related macular degeneration (AMD).
Macular degeneration has two forms:
Dry MD is the more common form, affecting approximately 90 percent of those who have macular degeneration. It typically develops slowly and causes mild visual distortion to moderate central vision loss.
Wet MD affects only 10 percent of people with macular degeneration, but causes more severe vision loss. In wet MD, new blood vessels that form under the macula leak fluid and can cause a rapid and severe loss of central vision. Wet macula degeneration can be more alarming and requires treatment with an ophthalmologist. Often the only way to remove the swelling around the macula is with medication administered by the doctor. Once this medication has been effective at removing the swelling, dry macula degeneration often remains.
How common is Macular Degeneration?
Macular degeneration is the most common cause of severe vision loss among individuals over age 65. Age is the greatest risk factor. People over 40 have a 4% risk, over 50 have a 9% risk, over 65 have a 23% risk and over 80 have a 31% risk. It accounts for 45% of the legally blind and 70% of the seriously visually impaired people over 70.
Other risk factors include:
- A family history of MD
- High cholesterol
- A poor ability to tan when young
- Excessive exposure to sunlight
- High dietary intake of saturated fat and cholesterol
- Uncontrolled hypertension
- A high body mass index in men
- Race - MD affects Caucasians more frequently than people of other races
- Gender - Women are twice as likely to develop MD
A diet that is high in antioxidants derived from green leafy vegetables has been proven to protect the eye against macular degeneration. These antioxidants, lutein and zeaxanthin, can be found in supplements, such as MDEyes and Macuvision Plus.
Early signs of macular degeneration can be identified by our optometrist through retinal slit-lamp assessment and OCT scans. The OCT provides a cross sectional image of the macula. If you have not had your macula examined, it is time to make an appointment with our local optometrist here at The Eyewear Shop.