What is Age Related Macular Degeneration (AMD)?
Age-related macular degeneration (AMD) is a deterioration of the macula inside the eye. The macula is a small area in the retina that is responsible for your central vision. This small area of the retina is much more sensitive to detail than the rest of the retina (called the peripheral retina--which gives you side vision). The macula is what allows you to see colors, thread a needle, read small print, and read street signs. Many older people develop macular degeneration as part of the aging process.
What are the symptoms of AMD?
Many people are not aware that they have macular degeneration until they have a noticeable vision problem or until it is detected during an eye examination. You may have symptoms such as blurriness, dark areas or distortion in your central vision, and perhaps permanent loss of your central vision. It usually does not affect your peripheral vision. For example, with advanced macular degeneration, you could see the edges of a person’s face, but not see the details of eyes, nose or mouth. People with more advanced cases of macular degeneration continue to have useful peripheral vision. In many cases, macular degeneration's impact on your vision can be minimal. When macular degeneration does lead to loss of vision, it usually begins in just one eye, although it may affect the other eye later. With or without treatment, macular degeneration almost never causes total blindness.
Is there more than one type of macular degeneration?
There are two types of macular degeneration: 1) Dry AMD with drusen (atrophic) and 2) Wet AMD (exudative) with abnormal blood vessels.
Most people have the dry form. This condition is caused by aging and thinning of the tissues of the macula and usually begins when small pieces of fatty protein, called drusen, form under the retina. With dry macular degeneration, vision loss is usually gradual. People who develop dry macular degeneration must carefully and constantly monitor their central vision using an Amsler grid. Your eye doctor will teach you how to use this home vision test. While there is no medication or treatment for dry AMD, some people may benefit from a vitamin therapy regimen.
Only about 10 percent of people who have macular degeneration have the wet form, but it can cause more damage than the dry form. Wet macular degeneration occurs when abnormal blood vessels begin to grow underneath the retina and leak fluid or blood which may blur or distort your central vision. Vision loss from this form of macular degeneration may occur faster and be more noticeable. The earlier that wet macular degeneration is diagnosed and treated, the better chance you have of preserving your central vision. There is a risk it can affect the fellow eye, so it is important that you and your eye doctor monitor your vision in each eye carefully.
Who is at risk for AMD?
New information on macular degeneration has been discovered recently. Genetic changes may contribute to approximately 50% of individuals who get macular degeneration. Many older people develop macular degeneration as part of the body's natural aging process. Smoking, high cholesterol, and high blood pressure are associated with the wet form of macular degeneration. Research also suggests there may be a link between obesity and having early or intermediate-stage macular degeneration develop into the advanced (wet) form.
How is AMD diagnosed?
Regular dilated eye exams by an eye doctor may help to detect problems or early stages of macular degeneration before you are even aware of them. Other tests may include specialized imaging of the retina.
How is AMD treated?
Dry AMD-Unfortunately, at this time there is no single proven treatment for the dry form of macular degeneration. However, studies have shown that taking a dietary supplement of vitamin C, vitamin E, lutein and zeaxanthin, along with zinc, lowered the risk of macular degeneration progressing to advanced stages by at least 25%. Another large study in women showed a benefit from taking folic acid and vitamins B6 and B12. Eating dark leafy greens, and yellow, orange and other colorful fruits and vegetables, rich in lutein and zeaxanthin, may also reduce your risk for developing macular degeneration. These vitamins and minerals are recommended in specific daily amounts in addition to a healthy, balanced diet.
It is very important to remember that vitamin supplements are not a cure for macular degeneration, nor will they give you back vision that may have already been lost. However, specific amounts of these supplements do play a key role in helping some people at high risk for developing advanced wet AMD to maintain their vision, or slow down the progression of the disease. Talk with your eye doctor to find out if you are at risk for developing advanced macular degeneration, and to learn if supplements are recommended for you.
Wet AMD-Treating the wet form of macular degeneration may involve the use of anti-VEGF injections, thermal laser treatment or photodynamic therapy (PDT). Treatment of wet macular degeneration generally reduces, but does not eliminate, the risk of severe vision loss. It is important to remember that only about 10% of all macular degeneration cases are exudative, or wet form, and about 75% of these cases cannot be treated. Most importantly, people with wet or dry macular degeneration who cannot be treated will not become blind, as they will still have peripheral vision.
The best way to care for your vision is to wear hats, sunglasses and sunscreen every day, eat a balanced diet, avoid smoking, and have regular dilated eye exams. If you have any vision symptoms, concerns, or it has been more than 2 years since your last eye exam, please call us to schedule an appointment (650-259-0300). For more information on macular degeneration please go to the American Academy of Ophthalmology website link listed here.