What is Macular Degeneration?
Dr. Diane Bovenkamp
Dr. Diane Bovenkamp, Science Communications Specialist at BrightFocus, provides an overview of macular degeneration, a leading cause of vision loss in Americans 60 and older, and the second-highest cause of irreversible visual impairment in the world.
Ed Berger: Hi, I’m Ed Berger, and I’m with Macular Degeneration Research, a program of the BrightFocus Foundation, a nonprofit organization leading the fight to save sight and mind.
Today, our topic is age-related macular degeneration, an eye disease that is not very well known, but yet is a leading cause of vision loss in Americans 60 years of age and older. And it’s the second-highest cause of irreversible visual impairment in the world.
Dr. Diane Bovenkamp, Science Communications Specialist at BrightFocus, is going to help us learn more about this devastating eye disorder.
Dr. Diane Bovenkamp: It's nice to be here.
Ed Berger: Diane, let’s start with the basics. What is the macula and where is it located in the eye?
Dr. Diane Bovenkamp: The macula is the central area of the retina, which is the paper-thin tissue at the back of the eye where light sensitive cells send visual signals to the brain. The macula is responsible for processing sharp, clear, straight-ahead vision.
Ed Berger: So, if I were reading a book, watching television, or looking directly at someone’s face, I would be using the macula.
Dr. Diane Bovenkamp: That’s right. So, it can be devastating if the cells in the macula begin to degenerate or die, as they do in macular degeneration. Many daily activities such as driving, reading, and recognizing faces would become increasingly difficult.
Ed Berger: Do researchers have any idea what causes this eye disease?
Dr. Diane Bovenkamp: Well, there is a strong genetic component to this disease, but it is highly likely that its development is due to a combination of factors. Scientists believe this includes genetic inheritance and environmental factors such as sunlight exposure, diet, and smoking.
Ed Berger: I understand that there are two forms of macular degeneration…
Dr. Diane Bovenkamp: Yes, that is right. The two forms are referred to as wet and dry. In the dry form, which accounts for approximately 85 – 90 percent of the cases, deposits called drusen build up in the retina. The light-sensitive cells in the macula then slowly break down. In the wet form, abnormal blood vessels grow behind the macula. These vessels are very fragile and can leak fluid and blood, resulting in scarring of the macula and the potential for rapid, severe damage and loss of vision.
Ed Berger: So, how would someone know if he or she is developing this condition?
Dr. Diane Bovenkamp: Well, during the early stages of macular degeneration, and if only one eye is affected, there may be no symptoms. Additionally, neither form of macular degeneration causes pain. However, an eye doctor may be able to detect early signs of the disease before symptoms appear. So, it’s very, very important to have regular, comprehensive eye examinations to detect these signs as soon as possible.
Often, the dry form of macular degeneration initially causes slightly blurred central vision. The center of vision may become bit fuzzy or shadowed, and this area can grow larger as the disease progresses. Blind spots may develop, and it can become more difficult to see color and fine detail.
In wet macular degeneration, in addition to the above symptoms, it is common for straight lines to appear wavy, due to the pooling of fluid and lifting of the retina. Also, in this more severe form, central vision loss can occur rapidly, sometimes within days or weeks, so it’s essential to immediately contact your doctor if you experience any of these symptoms. Regular use of an Amsler grid can help to detect these changes in vision.
Ed Berger: What is an Amsler grid?
Dr. Diane Bovenkamp: It’s a hand-held chart with a grid of straight lines and a black dot in the middle. If you cover one eye and look at the dot and any of the lines appear dim, irregular, wavy or fuzzy, you should schedule an eye exam immediately.
Ed Berger: Are there effective treatments for this eye disease?
Dr. Diane Bovenkamp: There is currently no treatment for dry macular degeneration; however, taking a specific high-dose supplement of vitamins and minerals (called the “AREDS” formula) can significantly reduce the risk of progressing from intermediate dry macular degeneration to advanced or wet macular degeneration. The results of a follow-up clinical trial, called AREDS2, should be available within the next year or so. In that study researchers have adjusted the AREDS formula and added certain antioxidants and omega-3 fatty acids.
The wet form of the disease is currently treated by injections into the eye with drugs that inhibit the growth of the abnormal blood vessels. This treatment does not cure the disease and will not bring back vision that is already lost due to the loss of the light-sensitive cells in the macula.
Ed Berger: : Thank you, Diane for this very helpful information, and thanks everyone for listening. Stay tuned for future podcasts on macular degeneration. For more information about macular degeneration or to get involved in advancing research to end this degenerative eye disease, visit brightfocus.org, or call 1-855-345-6MDR.
Thanks again everyone.