Definition: Age-Related Macular Degeneration (ARMD) is a chronic eye disease that occurs when tissue in the macula, the part of your retina that's responsible for central vision, deteriorates. The retina is the layer of tissue on the inside back wall of your eyeball. Degeneration of the macula results in blurred central vision or a blind spot in the center of your visual field.
Signs and symptoms: Macular Degeneration usually develops gradually and painlessly. The signs and symptoms of the disease may vary, depending on which of the two types of macular degeneration you have.
Initially, you may notice the following symptoms:
- The need for increasingly bright illumination when reading or doing close work
- Printed words that appear increasingly blurry
- Colors that seem washed out and dull
- Gradual increase in the haziness of your overall vision
- Blind spot in the center of your visual field combined with a profound drop in your central vision
In either form of Macular Degeneration, your vision may falter in one eye while the other remains fine for years. You may not notice much change because your good eye compensates for the weak one. Your vision and lifestyle begin to be dramatically affected as this condition develops in both eyes.
Causes: The macula is the center of your retina and is made up of densely packed light-sensitive cells called cones and rods. These cells, particularly the cones, are essential for central vision. The choroid is an underlying layer of blood vessels that nourishes the cones and rods of the retina. A layer of tissue forming the outermost surface of the retina is called the retinal pigment epithelium (RPE). The RPE is a critical passageway for nutrients from the choroid to the retina and helps remove waste products from the retina to the choroid.
As you age, the RPE may deteriorate and become thin (a process known as atrophy), which sets off a chain of events. The nutritional and waste-removing cycles between the retina and the choroid are interrupted. Waste deposits begin to form. Lacking nutrients, the light-sensitive cells of the macula become damaged. The damaged cells can no longer send normal signals through the optic nerve to your brain, and your vision becomes blurred. This is often the first symptom of dry, or atrophic, Macular Degeneration.
Wet Macular Degeneration accounts for about 10 percent of cases of Age-Related Macular Degeneration. Wet Macular Degeneration is also called choroidal neovascularization, subretinal neovascularization, exudative, or disciform degeneration.
When one has the wet form of Macular Degeneration, abnormal blood vessels begin to grow in order to make up for the lack of nutrients. This is called neovascularization. The abnormal blood vessels easily break and leak fluid, damaging photoreceptor cells and causing swelling of the macula and hemorrhaging. Wet Macular Degeneration tends to progress rapidly and can cause severe damage to central vision. In order to detect the formation of the abnormal blood vessels early, you should have regular dilated eye exams as determined by your ophthalmologist.
Treatment: Currently there's no treatment for dry Macular Degeneration. But this doesn't mean you'll eventually lose all of your sight. Dry Macular Degeneration usually progresses slowly; so many people with this condition are able to live relatively normal, productive lives, especially if only one eye is affected.
In some cases, if wet Macular Degeneration is diagnosed early, laser surgery can prevent extensive central vision loss. In this type of surgery, laser beams destroy the leaky blood vessels that form beneath the macula. For laser surgery to be effective, it is critical that wet Macular Degeneration be diagnosed before extensive vision loss occurs. Therefore, individuals should consult with an eye doctor at the first sign of blurred or distorted central vision.
Two types of medication have also been shown to improve vision. These are anti-VEGF treatments, know as Avastin and Lucentis. VEGF is a necessary component in the production of abnormal blood vessels. The medication is injected into the eye.
Prevention: Nothing you do can change your race or genetic makeup or keep you from getting older — all major risk factors for Macular Degeneration. But preliminary evidence suggests that any of the following measures may help prevent or delay the development of Macular Degeneration. These measures are best started before Macular Degeneration develops and your vision starts to decrease:
Eat foods containing antioxidants. People at high risk of the advanced stages of Macular Degeneration may be able to lower that risk with a dietary supplement of antioxidants, zinc and copper. Antioxidants are substances that prevent oxidative damage to tissue such as the retina. Foods with antioxidants are those rich in vitamins A, C and E. And it helps to eat a nutritionally balanced, low-fat diet containing five or more servings of fruits and vegetables every day. The antioxidants lutein and zeaxanthin are nutrients found in high concentrations in egg yolk, corn and spinach. Preliminary studies show that high levels of lutein and zeaxanthin in your blood may protect your retina.
Wear sunglasses that block out harmful ultraviolet light. Orange-, yellow- or amber-tinted lenses can filter out both ultraviolet light and blue light that may damage your retina.
Stop smoking. Smokers are up to three times more likely to develop Macular Degeneration than nonsmokers. Ask your doctor for help to stop smoking.
Manage your other diseases. For example, if you have cardiovascular disease or high blood pressure, take your medication and follow your doctor's instructions for controlling the condition. If it's not well controlled, it may contribute to the onset of Macular Degeneration.
Get regular eye exams. Early detection of Macular Degeneration increases your chances of preventing serious vision loss. If you're over the age of 50, get an exam every 2 to 5 years. If you have a family history of Macular Degeneration, have your eyes examined more frequently, perhaps annually.
Screen your vision regularly. If you've received a diagnosis of early-stage Macular Degeneration, your doctor may suggest that you regularly monitor your vision at home with an Amsler grid. Doing so may help you to detect subtle changes in your vision at the earliest possible time and seek help promptly.
Fish oil or Omega-3-Fatty Acids: You can protect against the progression of Age-Related Macular Degeneration (ARMD) by including omega-3 fatty acids in your diet. Eating two to three servings of fish rich in omega-3 fatty acids (e.g., salmon, tuna, mackerel, herring) per week will provide the recommended daily intake of DHA and EPA. Or, you can take over-the-counter fish oil supplements. Look for products that contain 350 to 380 mg of EPA and 230 to 260 mg of DHA per daily dose.