Macular degeneration is the leading cause of severe vision loss in people over age 60. It occurs when the small central portion of the retina, known as the macula, deteriorates. The retina is the light-sensing nerve tissue at the back of the eye. Because the disease develops as a person ages, it is often referred to as age-related macular degeneration (AMD). Although macular degeneration is almost never a totally blinding condition, it can be a source of significant visual disability. We caught up with Dr. Trey Gerdes of Eye Fashion Optical of Waco to find out more about this very serious condition.
Q: Dr. Gerdes, Can you help us understand macular degeneration?
There are two main types of age-related macular degeneration, a wet form and a dry form.
Your optometrist will examine the macula, the portion of the retina that is responsible for your central vision, as part of a comprehensive eye exam.
Most patients with macular degeneration have the dry form of the disease and can lose some form of central vision. However, the dry form of macular degeneration can lead to the wet form. Although only about 10% of people with macular degeneration develop the wet form, they make up the majority of those who experience serious vision loss from the disease.
It is very important for people with macular degeneration to monitor their eyesight carefully and see their eye doctor on a regular basis.
Q: Who is at risk for developing macular degeneration?
Well, as the name suggests, age-related macular degeneration is more common in older adults. In fact, it is the leading cause of severe vision loss in adults over age 60.
Macular degeneration may be hereditary, meaning it can be passed on from parents to children. If someone in your family has or had the condition you may be at higher risk for developing macular degeneration. Talk to your eye doctor about your individual risk.
Smoking, high blood pressure, high cholesterol, obesity, and being light skinned, female, and having a light eye color are also risk factors for macular degeneration.
Q: Can you talk a little more about dry AMD?
The "dry" form of macular degeneration is characterized by the presence of yellow deposits, called drusen, in the macula. A few small drusen may not cause changes in vision; however, as they grow in size and increase in number, they may lead to a dimming or distortion of vision that people find most noticeable when they read. In more advanced stages of dry macular degeneration, there is also a thinning of the light-sensitive layer of cells in the macula leading to atrophy, or tissue death. In the atrophic form of dry macular degeneration, patients may have blind spots in the center of their vision. In the advanced stages, patients lose central vision.
Q: What about wet AMD?
AMD, the "wet" form of macular degeneration, is characterized by the growth of abnormal blood vessels from the choroid underneath the macula. This is called choroidal neovascularization. These blood vessels leak blood and fluid into the retina, causing distortion of vision that makes straight lines look wavy, as well as blind spots and loss of central vision. These abnormal blood vessels eventually scar, leading to permanent loss of central vision.
Q: I understand that the earlier macular degeneration is detected and the earlier the disease is treated, the better the outcome. What are some early warning signs people should look for?
In its early stages, macular degeneration may not have symptoms and may be unrecognized until it progresses or affects both eyes. The first sign of macular degeneration is usually a dim, blurry spot in the middle of your vision. This spot may get bigger or darker over time.
Symptoms of macular degeneration include:
Dark, blurry areas in the center of vision
Diminished or changed color perception
Q: There has been talk about the link between certain vitamins and minerals and the prevention of macular degeneration. Which nutrients should we be consuming (if any), and in what forms?
A large study performed by the National Eye Institute of the National Institutes of Health, called AREDS (Age-Related Eye Disease Study), showed that for certain individuals, vitamins C, E, beta-carotene, zinc and copper can decrease the risk of vision loss in patients with intermediate to advanced dry macular degeneration. However, the ingredients of vision supplements may change with the completion of the AREDS2 study. This study sought to see if adding other vitamins and mineral to the supplement would improve results of the AREDS. The first addition was omega-3 fatty acids (fish oil), and the second was a combination of two carotenoids, lutein 10mg and zeaxanthin 2mg, which are found in leafy green vegetables and highly colored fruits and vegetables. The research showed:
Beta-carotene did not reduce the risk of progression of AMD.
Adding omega-3 to the AREDS formula did not reduce risk of progression of AMD.
The AREDS formula was still found to be protective with less zinc added.
People that took a formula with lutein and zeaxanthin and who may not have been taking enough in their diet showed further improvement with the new AREDS formula.
In general, people who took lutein and zeaxanthin instead of beta-carotene had more of a benefit.
Q: What are some treatment options for macular degeneration?
Anti-angiogenesis drugs such as (Avastin, Eyelea, Lucentis, Macugen) block the development of new blood vessels and leakage from the abnormal vessels within the eye that cause wet macular degeneration. This treatment has been a major change in the treatment of this condition and many patients have actually regained vision that was lost.
Another treatment is high-energy laser light can sometimes be used to destroy actively growing abnormal blood vessels that occur in macular degeneration.
There is also a two-step treatment in which a light-sensitive drug (Visudyne) is used to damage the abnormal blood vessels. A doctor injects the drug into the bloodstream to be absorbed by the abnormal blood vessels in the eye. The doctor then shines a cold laser into the eye to activate the drug, damaging the abnormal blood vessels.
For those whose vision has been diminished by the disease, there are devices available that have special lenses or electronic systems that produce enlarged images of nearby objects. They help people who have vision loss from macular degeneration make the most of their remaining vision.
Q: How successful are these treatments?
People that took a formula with lutein and zeaxanthin and who may not have been taking enough in their diet showed further improvement with the new AREDS formula. In general, people who took lutein and zeaxanthin instead of beta-carotene had more of a benefit.
Anti-angiogenesis drugs, Laser therapy and Photodynamic laser therapy treaments may help but need to be repeated during follow-up visits. Low vision aids can help if central vision is active.
9. Are there any new and exciting treatment approaches or technologies on the horizon?
The following treatments are considered experimental and have been used less often since the development of anti-angiogenic medications have developed:
Submacular surgery. Surgery to remove the abnormal blood vessels or blood.
Retinal translocation. A surgical procedure used to destroy abnormal blood vessels that are located directly under the center of the macula, where a laser beam cannot be placed safely. In the procedure, the macular center is rotated away from the abnormal blood vessels to a healthy area of the retina, thus preventing the formation of scar tissue and further damage to the retina. Once moved away from the abnormal blood vessels, a laser is used to treat the abnormal blood vessels.
10. What are the most common misconceptions that people have about macular degeneration?
A lot percentage of patients believe that when diagnosed they will go blind. People rarely lose all of their vision from age-related macular degeneration. They may have poor central vision, but they are still able to perform many normal daily activities.
The wet form of macular degeneration is a leading cause of irreversible vision loss. When both eyes are affected, you may experience a significant decrease in your quality of life.
The dry form of age-related macular degeneration is much more common and tends to progress more slowly, allowing you to keep most of your vision.
Unfortunately, even after wet macular degeneration treatment, the condition can recur and require repeated treatments. Because of this, individuals with macular degeneration must test their own vision regularly and follow the recommendations of their optometrist. Successful and timely treatment will slow the rate of vision loss and often improve vision.
11. Is there a cure?
There is currently no cure for macular degeneration, but treatments may prevent severe vision loss or slow the progression of the disease considerably. Make sure your schedule your eye exam at Eye Fashion Optical for early detection.