Macular degeneration, dry

Definition

Dry macular degeneration is a chronic eye disease that causes vision loss in the center of your field of vision. Dry macular degeneration is marked by deterioration of the macula (MAK-u-luh), which is in the center of the retina — the layer of tissue on the inside back wall of your eyeball.

Dry macular degeneration is one of two types of age-related macular degeneration. The other type — wet macular degeneration — is characterized by swelling caused by leaky blood vessels in the back of the eye. Dry macular degeneration isn't associated with swelling and is the more-common form of the disease.

Dry macular degeneration doesn't cause total blindness, but it worsens your quality of life by blurring or causing a blind spot in your central vision. Clear central vision is necessary for reading, driving and recognizing faces.

Symptoms

Dry macular degeneration symptoms usually develop gradually. You may notice these vision changes:

  • The need for increasingly bright light when reading or doing close work
  • Increasing difficulty adapting to low light levels, such as when entering a dimly lit restaurant
  • Increasing blurriness of printed words
  • A decrease in the intensity or brightness of colors
  • Difficulty recognizing faces
  • A gradual increase in the haziness of your overall vision
  • A blurred or blind spot in the center of your field of vision
  • Hallucinations of geometric shapes or people, in cases of advanced macular degeneration

Dry macular degeneration may affect one eye or both eyes. If only one eye is affected, you may not notice any or much change in your vision because your good eye compensates for the weak one.

When to see a doctor
See your eye doctor if:

  • You notice changes in your central vision
  • Your ability to see colors and fine detail becomes impaired

These changes may be the first indication of macular degeneration, particularly if you are older than 50.

Causes

The exact cause of dry macular degeneration is unknown, but the condition develops as the eye ages. Dry macular degeneration affects the macula — a small area at the center of your retina that is responsible for clear vision, particularly in your direct line of sight. Over time the cells that make up your macula break down.

Risk factors

Factors that may increase your risk of macular degeneration include:

  • Increasing age. Your risk of macular degeneration increases as you age. Macular degeneration is most common in people over age 60.
  • Having a family history of macular degeneration. If someone in your family had macular degeneration, your odds of developing macular degeneration are higher.
  • Being white. Macular degeneration is more common in whites than it is in other races, especially after age 75.
  • Being female. Women are more likely than are men to develop macular degeneration.
  • Smoking cigarettes. Smoking cigarettes increases your risk of macular degeneration.
  • Being obese. Being severely overweight increases the chance that early or intermediate macular degeneration will progress to the more severe form of the disease.
  • Eating few fruits and vegetables. A diet that includes few fruits and vegetables may increase the risk of macular degeneration.
  • Having high blood pressure. Diseases that affect the circulatory system, such as high blood pressure, may increase the risk of macular degeneration.
  • Having high cholesterol. An elevated cholesterol level in your blood is associated with an increased risk of macular degeneration.

Complications

Progression to wet macular degeneration
At any time, dry macular degeneration can progress to a more severe form of the disease called wet macular degeneration, which causes rapid vision loss. There's no accurate way to predict who will eventually develop wet macular degeneration and who won't.

Preparing for your appointment

To check for macular degeneration, a dilated eye exam is generally necessary. Make an appointment with a doctor who specializes in eye care — an optometrist or an ophthalmologist — who can evaluate your condition and perform a complete eye exam.

What you can do
Appointments can be brief. Make the best use of the limited time by preparing beforehand. For instance:

  • Be aware of any pre-appointment restrictions. When you make the appointment, ask if there's anything you need to do in advance.
  • Write down any symptoms you're experiencing, including any that may seem unrelated to your vision problem.
  • Make a list of all medications, vitamins or supplements that you're taking.
  • Ask a family member or friend to accompany you. Having your pupils dilated for the eye exam may compromise your vision for a time afterward. You may need someone to drive or accompany you home from your appointment.

Questions to ask your eye doctor

  • What kind of macular degeneration do I have?
  • What is the visual acuity in my central vision?
  • How advanced is my macular degeneration?
  • Is it safe for me to drive?
  • Will I experience further vision loss?
  • Will taking a vitamin or mineral supplement help prevent further vision loss?
  • What's the best way to monitor my vision for any changes?
  • What low vision aids or adaptive devices might be helpful to me?

Questions your eye doctor may ask

  • When did you first notice your vision problem?
  • Does the condition affect one or both eyes?
  • Do you have trouble seeing things near you, at a distance or both?
  • Do you smoke?
  • Do you take any vitamins or supplements?
  • What medications do you take?
  • What foods does your diet include?
  • Do you have a family history of macular degeneration?

Tests and diagnosis

Diagnosing dry macular degeneration
Diagnostic tests for dry macular degeneration may include:

  • Testing for defects in your central vision. During a complete eye exam, your eye doctor may use a test called the Amsler grid to test for defects in the center of your vision. If you have macular degeneration, when you look at the grid some of the straight lines may seem faded, broken or distorted.
  • Examining the back of your eye. Your eye doctor will examine the back of your eye to look for a mottled appearance that's caused by drusen — yellow deposits that form in people with macular degeneration. To examine the back of your eye, your eye doctor will dilate your eyes using eyedrops and then use a special magnifying lens.
  • Creating images of the blood vessels in your eye (angiogram).During an angiogram of your eye, a colored dye is injected into a vein in your arm. The dye travels to the blood vessels in your eye. A special camera is used to take pictures of your eye. The pictures show the dye highlighting the blood vessels in your eye. Your eye doctor uses the information from the angiogram images to determine whether the back of your eye shows blood vessel or retinal abnormalities, such as those that might be associated with wet macular degeneration.
  • Optical coherence tomography. This noninvasive imaging test helps identify and display areas of retinal thickening or thinning. Such changes are associated with macular degeneration. It's often used to help monitor the response of the retina to macular degeneration treatments.

Determining the stage of your dry macular degeneration
Dry macular degeneration is categorized in three stages based on the progression of damage in your eye:

  • Early stage. Several small drusen or a few medium-sized drusen are detected on the macula in one or both eyes. Generally, there's no vision loss in the earliest stage.
  • Intermediate stage. Many medium-sized drusen or one or more large drusen are detected in one or both eyes. At this stage, your central vision may start to blur and you may need extra light for reading or doing detail work.
  • Advanced stage. Several large drusen, as well as extensive breakdown of light-sensitive cells in the macula, are detected. This causes a well-defined spot of blurring in your central vision. The blurred area may become larger and more opaque over time.

Treatment and drugs

There's no treatment available to reverse dry macular degeneration. But this doesn't mean you'll eventually lose all of your sight. Dry macular degeneration usually progresses slowly, and many people with the condition are able to live relatively normal, productive lives, especially if only one eye is affected. Your doctor may recommend annual eye exams to see if your condition is progressing.

Increased vitamin intake
Taking a high-dose formulation of antioxidant vitamins and zinc may reduce the progression of dry macular degeneration to vision loss, according to research by the National Eye Institute (NEI). In its research, the NEI used a formulation that included:

  • 500 milligrams (mg) of vitamin C
  • 400 international units (IU) of vitamin E
  • 15 mg of beta carotene (often as vitamin A — up to 25,000 IU)
  • 80 mg of zinc (as zinc oxide)
  • 2 mg of copper (as cupric oxide)

Ask your doctor whether this formulation may help you reduce your risk of vision loss. Studies found this specific combination of vitamins can't cure severe vision loss, but it may reduce the risk of vision loss in people with intermediate macular degeneration. If you have advanced stage macular degeneration in one eye, this combination of vitamins may reduce the risk that you'll develop vision loss in your other eye. But for people with early-stage dry macular degeneration, there's no evidence that these vitamins provide a benefit.

Tell your doctor if you smoke, since beta carotene supplements have been linked to an increased risk of lung cancer in smokers. Your doctor may recommend an alternative formulation of vitamins for you.

Your doctor may also recommend lifestyle changes to incorporate more of the fruits and vegetables that contain these vitamins into your diet, along with other foods, such as fish, that contain nutrients believed to contribute to eye health. Some people may prefer to make lifestyle changes, rather than take supplements. Others may wish to combine supplements with lifestyle changes. Discuss your options with your doctor.

Surgery to implant a telescopic lens in one eye
For people with advanced macular degeneration in both eyes, one option to improve vision may be surgery to implant a telescopic lens in one eye. The telescopic lens, which looks like a tiny plastic tube, is equipped with lenses that magnify your field of vision. The telescopic lens implant may improve both distance and close-up vision.

Lifestyle and home remedies

Changing your diet to include more fruits and vegetables and other healthy foods may help you prevent vision loss if you've been diagnosed with macular degeneration. Try to:

  • Include a variety of colorful fruits and vegetables in your diet.The antioxidant vitamins in the fruits and vegetables contribute to eye health. Eating a variety of colors ensures that you're getting a variety of vitamins.
  • Choose healthy fats. Healthy unsaturated fats, such as the fats found in olive oil, may help protect your vision. Choose these healthy fats over saturated fats, such as butter, and trans fats, such as partially hydrogenated oils found in packaged foods.
  • Choose whole grains over refined grains. Choose whole grains, such as whole-wheat bread, over refined grains, such as white bread.
  • Add fish to your diet. Fish contain omega-3 fatty acids that may help reduce the risk of vision loss related to macular degeneration. Fish that contain high levels of omega-3 fatty acids include salmon, sardines and tuna. Omega-3 fatty acids can also be found in supplements and nuts, such as walnuts.

Coping and support

Macular degeneration doesn't affect your side (peripheral) vision and usually doesn't cause total blindness. But it can reduce or eliminate your central vision — which is important for driving, reading and recognizing people's faces. It may help to work with a low vision rehabilitation specialist or occupational therapist who can help devise ways to help you adapt to your changing vision.

Ways to cope with your changing vision might include:

  • Ask your eye doctor to check your eyeglasses. Optimize the vision you have by getting the most appropriate prescription lenses for your eye glasses. Bifocal lenses may be helpful.
  • Use magnifiers. A variety of magnifying devices can help you with reading and other close-up work, such as sewing. Traditional hand-held magnifying lenses are one option. Others, such as special magnifying lenses you wear just like glasses, may be available from your eye doctor, at specialty stores or from a vision rehabilitation specialist. Another option may be a closed-circuit television system that uses a video camera to magnify reading material and project it on a video screen.
  • Change the display on your computer. Adjust the font size in your computer's settings. Adjust your monitor to show more contrast.
  • Select special appliances made for low vision. Some clocks, radios, telephones and other appliances have extra-large numbers. Other gadgets can talk to tell you the time or other important information. You may find it easier to watch television on a television with a larger screen.
  • Use brighter lights in your home. This will help with reading and other activities.
  • Use caution when driving. First, check with your doctor to see if driving is still safe based on your current visual acuity. When you do drive, there are certain situations that require extra caution, such as driving at night, in heavy traffic or in bad weather.
  • Consider other travel options. Use public transportation or ask family members to help, especially with night driving. Make arrangements to use local van or shuttle services, volunteer driving networks or ride shares.

Prevention

The following measures may help you avoid macular degeneration:

  • Have routine eye exams. Ask your eye doctor how often you should undergo routine eye exams. A dilated eye exam can identify macular degeneration.
  • 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.
  • Stop smoking. Smokers are more likely to develop macular degeneration than are nonsmokers. Ask your doctor for help to stop smoking.
  • Maintain a healthy weight. If you need to lose weight, reduce the number of calories you eat and increase the amount of exercise you get each day. If you have a healthy weight, work to maintain your weight by exercising most days of the week.
  • Choose a diet rich in fruits and vegetables. Choose a healthy diet that's full of a variety of fruits and vegetables. These foods contain antioxidant vitamins that reduce your risk of developing dry macular degeneration.
  • Include fish in your diet. Omega-3 fatty acids, which are found in fish, may reduce the risk of dry macular degeneration. Nuts, such as walnuts, also contain omega-3 fatty acids.

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