Dry macular degeneration

Overview

Dry macular degeneration is a common eye disorder among people over 50. It causes blurred or reduced central vision due to the breaking down of the inner layers of the macula (MAK-u-luh). The macula is the part of the retina that gives the eye clear vision in the direct line of sight.

Dry macular degeneration may start in one eye before developing in the other eye. It also may develop in both eyes at the same time. Over time, vision may worsen and affect the ability to do things, such as read, drive and recognize faces. But having dry macular degeneration doesn't mean you'll lose all your sight. Vision loss is typically central, and people retain their peripheral vision. Some people have only mild central vision loss. In others, it can be more severe.

Early detection and self-care measures may delay vision loss due to dry macular degeneration.

Symptoms

Dry macular degeneration symptoms usually develop gradually and without pain. They may include:

• Visual distortions, such as straight lines seeming bent.
• Reduced central vision in one or both eyes.
• The need for brighter light when reading or doing close-up work.
• Increased difficulty adapting to low light levels, such as when entering a dimly lit restaurant or theater.
• Increased blurriness of printed words.
• Difficulty recognizing faces.
• A well-defined blurry spot or blind spot in the field of vision.

Dry macular degeneration can affect one or both eyes. If only one eye is affected, you may not notice any changes in your vision. This is because your good eye may compensate for the affected eye. And the condition doesn't affect the side vision, so it does not cause total blindness.

Dry macular degeneration is one of two types of age-related macular degeneration. It can progress to wet macular degeneration, which is when blood vessels grow and leak under the retina. The dry type is more common, but it usually progresses slowly over years. The wet type is more likely to cause a relatively sudden change in vision resulting in serious vision loss.

When to see a doctor

See your eye doctor if:

• You notice changes, such as distortion or blind spots, in your central vision.
• You lose the ability to see fine detail.

These changes may be the first sign of macular degeneration, particularly if you're over age 60.

Causes

No one knows exactly what causes dry macular degeneration. Research indicates that it may be a combination of family genes and environmental factors, including smoking, obesity and diet.

The condition develops as the eye ages. Dry macular degeneration affects the macula. The macula is the area of the retina that's responsible for clear vision in the direct line of sight. Over time, tissue in the macula may thin and lose cells responsible for vision.

Risk factors

Factors that may increase your risk of macular degeneration include:

• Age. This disease is most common in people over 60.
• Family history and genetics. This disease has a hereditary component. Researchers have identified several genes linked to the condition.
• Race. Macular degeneration is more common in white people.
• Smoking. Smoking cigarettes or being regularly exposed to tobacco smoke greatly increases your risk of macular degeneration.
• Obesity. Research indicates that being obese may increase your chance that early or intermediate macular degeneration will progress to the more severe form of the disease.
• Cardiovascular disease. If you have heart or blood vessel disease, you may be at higher risk of macular degeneration.

Complications

People whose dry macular degeneration has progressed to central vision loss have a higher risk of depression and social isolation. With profound loss of vision, people may see visual hallucinations. This condition is called Charles Bonnet syndrome. Dry macular degeneration may progress to wet macular degeneration, which can quickly cause vision loss if left untreated.

Prevention

It's important to have routine eye exams to identify early signs of macular degeneration. The following measures may help reduce your risk of developing dry macular degeneration:

• Manage all medical conditions. For example, if you have cardiovascular disease or high blood pressure, take your medicine and follow your health care provider's instructions for controlling the condition.
• Don't smoke. Smokers are more likely to develop macular degeneration than are nonsmokers. Ask your provider for help stopping smoking.
• Maintain a healthy weight and exercise regularly. If you need to lose weight, reduce the number of calories you eat and increase the amount of exercise you get each day.
• Choose a diet rich in fruits and vegetables. These foods contain antioxidant vitamins that reduce your risk of developing macular degeneration.
• Include fish in your diet. Omega-3 fatty acids, which are found in fish, may reduce the risk of macular degeneration. Nuts such as walnuts also contain omega-3 fatty acids.

Diagnosis

Your eye doctor may diagnose your condition by reviewing your medical and family history and conducting a complete eye exam. Other tests may be performed, including:

• Examination of the back of your eye. Your eye doctor puts drops in your eyes to dilate them and uses a special instrument to examine the back of your eye. The eye doctor looks for a mottled appearance that's caused by yellow deposits that form under the retina, called drusen. People with macular degeneration often have many drusen.
• A test for changes in the center of your vision. During an eye examination, your eye doctor may use an Amsler grid to test for changes in the center of your vision. If you have macular degeneration, some of the straight lines in the grid may look faded, broken or distorted.
• Fluorescein angiography. During this test, your eye doctor injects a dye into a vein in your arm. The dye travels to and highlights the blood vessels in your eye. A special camera takes several pictures as the dye travels through the blood vessels. The images will show if you have retinal or blood vessel changes, which are a sign of wet macular degeneration.
• Indocyanine green angiography. Like fluorescein angiography, this test uses an injected dye. It may be used alongside a fluorescein angiogram to identify specific types of macular degeneration.
• Optical coherence tomography. This noninvasive imaging test displays detailed cross-sectional images of the retina. It identifies areas where the retina may be thinning, thickening or swelling. These can be caused by fluid buildup from leaking blood vessels in and under your retina.

Treatment

For now, there's no way to reverse damage from dry macular degeneration. However, there are many clinical trials in progress. If your condition is diagnosed early, you can take steps to help slow its progression, such as taking vitamin supplements, eating healthy and not smoking.

Vitamin supplements

For people with intermediate or advanced disease, taking a high-dose formulation of antioxidant vitamins and minerals may help reduce the risk of vision loss. Research from the Age-Related Eye Disease Study 2 (AREDS2) has shown benefit in a formulation that includes:

• 500 milligrams (mg) of vitamin C.
• 400 international units (IU) of vitamin E.
• 10 mg of lutein.
• 2 mg of zeaxanthin.
• 80 mg of zinc (as zinc oxide).
• 2 mg of copper (as cupric oxide).

The evidence doesn't show benefit in taking these supplements for people with early-stage dry macular degeneration. Ask your eye doctor if taking supplements is right for you.

Low vision rehabilitation

Age-related macular degeneration doesn't affect your side vision and usually doesn't cause total blindness. But it can reduce or eliminate your central vision. Central vision is necessary for reading, driving and recognizing people's faces. It may help for you to get care from a low vision rehabilitation specialist, an occupational therapist, your eye doctor and others trained in low vision rehabilitation. They can help you find ways to adapt to your changing vision.

Surgery to implant a telescopic lens

For selected people with advanced dry macular degeneration in both eyes, an 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, but it has a very narrow field of view. It can be particularly useful in an urban environment to aid in identifying street signs.

Lifestyle and home remedies

Even after receiving a diagnosis of dry macular degeneration, you can take steps that may help slow vision loss.

• Don't smoke. If you smoke, ask your health care provider for help quitting.

• Choose a healthy diet. The antioxidant vitamins in fruits and vegetables contribute to eye health. Kale, spinach, broccoli, squash and other vegetables have high levels of antioxidants, including lutein and zeaxanthin, which may benefit people with macular degeneration. Eating foods containing high levels of zinc also may be helpful for people with macular degeneration. These include high-protein foods, such as beef, pork and lamb. Nonmeat sources include milk, cheese, yogurt, whole-grain cereals and whole-wheat bread.

  Another good choice is healthy unsaturated fat, such as in olive oil. And research studies have shown that a diet high in omega-3 fatty acids, such as in salmon, tuna and walnuts, may lower the risk of advanced age-related macular degeneration (AMD). But the same benefit is not shown from taking omega-3 supplements, such as fish oil pills.

• Manage your other medical conditions. If you have cardiovascular disease or high blood pressure, for example, take your medicine and follow your provider's instructions for controlling the condition.
• Maintain a healthy weight and exercise regularly. If you need to lose weight, reduce the number of calories you eat and increase the amount of exercise you get each day.
• Have routine eye exams. Ask your eye doctor about the recommended schedule for follow-up exams. In between checkups, you can do a self-assessment of your vision using an Amsler grid. These steps will help tell you if your condition develops into wet macular degeneration, which can be treated with medicines.

Coping and support

These tips may help you cope with your changing vision:

• Ask your eye doctor to check your eyeglass prescription. If you wear contacts or glasses, be sure your prescription is up to date. If new glasses don't help, ask for a referral to a low vision specialist.

• Use magnifiers. A variety of magnifying devices can help you with reading and other close-up work, such as sewing. Such devices include hand-held magnifying lenses or magnifying lenses you wear like glasses.

  You also may use a closed-circuit television system that uses a video camera to magnify reading material and project it on a video screen.

• Change your computer display and add audio systems. Adjust the font size in your computer's settings. And adjust your monitor to show more contrast. You also may add speech-output systems or other technologies to your computer.
• Use electronic reading aids and voice interfaces. Try large-print books, tablet computers and audiobooks. Some tablet and smartphone apps are designed to help people with low vision. And many of these devices now come with voice recognition systems, which can be a helpful low vision aid.
• Select special appliances made for low vision. Some clocks, radios, telephones and other appliances have extra-large numbers. You may find it easier to watch a television with a larger high-definition screen, or you may want to sit closer to the screen.
• Use brighter lights in your home. Better lighting helps with reading and other daily activities, and it also may reduce the risk of falling.
• Consider your transportation options. If you drive, check with your doctor to see if it's safe to continue doing so. Be extra cautious in certain situations, such as driving at night, in heavy traffic or in bad weather. Use public transportation or ask family members to help, especially with night driving. Or use local van or shuttle services, volunteer driving networks, or rideshares.
• Get support. Having macular degeneration can be difficult, and you may need to make changes in your life. You may go through many emotions as you adjust. Consider talking to a counselor or joining a support group. Spend time with supportive family members and friends.

Preparing for an appointment

You will likely need a dilated eye exam to check for macular degeneration. Make an appointment for a complete eye exam with a doctor who specializes in eye care — an optometrist or an ophthalmologist.

What you can do

Before your appointment:

• When you make the appointment, ask if you need to do anything to prepare.
• List any symptoms you're experiencing, including those that seem unrelated to your vision problem.
• List all medications, vitamins and supplements you take, including the doses.
• Ask a family member or friend to go with you. Having your pupils dilated for the eye exam will affect your vision for a time afterward, so you may need someone to drive or be with you after your appointment.
• List questions to ask your doctor.

For macular degeneration, questions to ask your eye doctor include:

• Do I have dry or wet macular degeneration?
• How advanced is my macular degeneration?
• Is it safe for me to drive?
• Will I experience further vision loss?
• Can my condition be treated?
• I have other health conditions. How can I best manage these conditions together?
• 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 changes in my symptoms warrant calling you?
• What low vision aids might be helpful to me?
• What lifestyle changes can I make to protect my vision?

What to expect from your doctor

Your eye doctor is likely to ask you a few questions, such as:

• When did you first notice your vision problem?
• Does the condition affect one or both eyes?
• Do you have trouble seeing things near to you, at a distance or both?
• Do you smoke or did you used to smoke? If so, how much?
• What types of foods do you eat?
• Do you have other medical problems, such as high cholesterol, high blood pressure or diabetes?
• Do you have a family history of macular degeneration?