What is macular degeneration

Macular degeneration or age-related macular degeneration (AMD) affects the macula, the part of the eye that allows you to see fine detail. Age-related macular degeneration causes no pain. An eye affected by macular degeneration will not be able to perceive detail or colors as well as a healthy eye. Progressive deterioration of the macula can lead to loss of central sight. However, it does not lead to complete blindness because the peripheral regions of the retina remain unaffected. Macular degeneration or age-related macular degeneration (AMD), is a leading cause of severe, irreversible vision loss in Americans 60 and older ¹⁾. In 2004, examining a slightly expanded age group, it was estimated that approximately 1.75 million people aged 40 years or older in the United States were estimated to have either neovascular age-related macular degeneration or geographic atrophy in at least one eye, and 7.3 million were considered to have high-risk features, such as large drusen in one or both eyes ²⁾. Overall, age-related macular degeneration is responsible for an estimated 46% of cases of severe visual loss (visual acuity 20/200 or worse) in persons over 40 years of age in the United States ³⁾. While most consider the onset of age-related macular degeneration as occuring in individuals over the age of 50, there are variations in the epidemiologic literature. Cases of advanced age-related macular degeneration that occur between ages 40 and 50 is very low, yet detection of the earlier stages, which are precursors of more advanced age-related macular degeneration, may well occur during this decade. Therefore, the reader must keep in mind that age-related macular degeneration is a disease spectrum with early and later stages. Although an estimated 80% of age-related macular degeneration patients have non-neovascular or atrophic age-related macular degeneration ⁴⁾, the neovascular form is responsible for nearly 90% of the severe visual acuity loss (20/200 or worse) from age-related macular degeneration ⁵⁾.

The region of the retina responsible for sharp, central sight is the macula. In the macula, the nerve cells of the retina are composed mainly of cone cells closely clustered together. Cone cells are highly sensitive to light and make detail vision and the perception of colors possible. The macula is nearly one hundred times more sensitive than the peripheral regions of the eye. The central focus of light is upon the retina is in the region of the macula to provide high resolution vision.

Macular degeneration is a disease that destroys the macula – your sharp, central vision you need for “straight-ahead” activities such as reading, sewing, and driving. You need central vision to see objects clearly and to do tasks such as reading and driving. Age-related macular degeneration (AMD) is a disease that blurs the sharp, central vision.

Age-related macular degeneration (AMD) does not hurt, but it causes cells in the macula to die. In some people, age-related macular degeneration advances so slowly that vision loss does not occur for a long time. In others, the disease progresses faster and may lead to a loss of vision in one or both eyes. As age-related macular degeneration progresses, a blurred area near the center of vision is a common symptom. Over time, the blurred area may grow larger or you may develop blank spots in your central vision. Objects also may not appear to be as bright as they used to be.

Age-related macular degeneration by itself does not lead to complete blindness, with no ability to see. However, the loss of central vision in age-related macular degeneration can interfere with simple everyday activities, such as the ability to see faces, drive, read, write, or do close work, such as cooking or fixing things around the house.

There are two types of age related macular degeneration: wet and dry.

1. Wet age-related macular degeneration happens when abnormal blood vessels grow under the macula. These new blood vessels often leak blood and fluid. This is the most serious kind. Wet age-related macular degeneration damages the macula quickly. Blurred vision is a common early symptom.
2. Dry age-related macular degeneration happens when the light-sensitive cells in the macula slowly break down. It is the most common kind. Your gradually lose your central vision. A common early symptom is that straight lines appear crooked.

Risk Factors for macular degeneration

Macular degeneration tends to have a higher incidence of occurrence when the following risk factors are present:

• Age: Macular degeneration can occur at any age; however, the chance of its occurrence increases nearly five-fold after the age of sixty-five.
• Heredity: Macular degeneration tends to “run in families.” This means that there is a genetic factor that predisposes a person toward developing the condition. Anytime a “bloodline” relative has macular degeneration, you run an increased chance of developing the condition.
• Gender: Women have a slightly higher incidence of developing macular degeneration than men.
• Ethnic Background: Fair-skinned people of northern European ancestry (Scandinavian, English, or German descent) have a higher chance of developing macular degeneration.
• Eye Color: Blue-eyed individuals are more prone to develop the condition than brown-eyed persons.
• Cardiovascular History: A history of heart disease or stroke is associated with a higher incidence of macular degeneration.
• Smoking: Macular degeneration tends to occur more frequently in persons who smoke. Even after treatment, smokers are reported to have a greater chance of having macular problems recur.

Symptoms of macular degeneration

Macular degeneration develops differently in each person. Because it will affect different regions of the macula from person to person, the symptoms tend to vary.

In general, the following symptoms are indicative of macular degeneration:

• The loss of the ability to see objects clearly.
• Vision that is noticeably distorted. Straight lines appear wavy. Objects may appear in wrong shape or size.
• The loss of clear, correct colors.
• A dark, empty area in the center of vision.

At the present time, there is no cure for macular degeneration. Treatment can slow vision loss. It does not restore vision. Depending upon the form of macular degeneration, there are treatments that can help to control the progression of the condition.

For an individual with macular degeneration, it is highly recommended that a regular schedule of eye examinations be maintained before the disease causes vision loss. During these examinations, detailed documentation is made through photographs and fluorescein angiography scans of the health of the retina. With this information, your eye doctor is better able to monitor the condition and note any changes that may occur.

Figure 1. Structure of the human eye

The Macula

The macula is made up of millions of light-sensing cells that provide sharp, central vision. It is the most sensitive part of the retina, which is located at the back of the eye. The retina turns light into electrical signals and then sends these electrical signals through the optic nerve to the brain, where they are translated into the images we see. When the macula is damaged, the center of your field of view may appear blurry, distorted, or dark.

Figure 2. Macula

Figure 3. Normal macula and retina (left eye)

Figure 4. Macular degeneration (right and left eyes)

How To Perform Amsler Grid Test

This test helps detect macular degeneration. If you normally wear glasses for reading, wear them for this test. If you wear bifocals, look through the bottom reading portion.

Do the test with each eye separately, first the right and then the left. Hold the test grid right in front of you, 14 inches (35centimeters) away from your eye. Look at the dot in the center of the grid, not at the grid pattern.

While looking at the dot, you will see the rest of the grid in your peripheral vision. All the lines, both vertical and horizontal, should appear straight and unbroken. They should meet at all the crossing points with no missing areas. If any lines appear distorted or broken, note their location on the grid using a pen or pencil.

Figure 5. Amsler grid

Dry macular degeneration

Dry macular degeneration is a common eye disorder among people over 65. It causes blurred or reduced central vision, due to thinning of the macula. The macula is the part of the retina responsible for clear vision in your direct line of sight.

Dry macular degeneration may first develop in one eye and then affect both. Over time your vision worsens, which may affect your ability to do things such as read, drive and recognize faces. But this doesn’t mean you’ll lose all of your sight.

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

Symptoms of dry macular degeneration

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 work
• Increased difficulty adapting to low light levels, such as when entering a dimly lit restaurant
• Increased blurriness of printed words
• Decreased intensity or brightness of colors
• Difficulty recognizing faces

Dry macular degeneration usually affects both eyes. If only one eye is affected, you may not notice any changes in your vision because your good eye may compensate for the weak eye. And the condition doesn’t affect side (peripheral) vision, so it rarely causes total blindness.

Dry macular degeneration is one of two types of age-related macular degeneration. It can progress to wet (neovascular) macular degeneration, which is characterized by blood vessels that grow under the retina and leak. 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.

Causes of dry macular degeneration

No one knows exactly what causes dry macular degeneration. But research indicates it may be related to a combination of heredity and environmental factors, including smoking and diet.

The condition develops as the eye ages. Dry macular degeneration affects the macula — an area of the retina that’s responsible for clear vision in your direct line of sight. Over time tissue in your macula may thin and break down.

Risk factors for dry macular degeneration

Factors that may increase your risk of macular degeneration include:

• Age. This disease is most common in people over 65.
• Family history and genetics. This disease has a hereditary component. Researchers have identified several genes that are related to developing the condition.
• Race. Macular degeneration is more common in whites than it is in other people.
• Smoking. Smoking cigarettes or being regularly exposed to smoke significantly 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 had diseases that affected your heart and blood vessels, you may be at higher risk of macular degeneration.

Complications of dry macular degeneration

People whose dry macular degeneration has progressed to central vision loss may experience depression or visual hallucinations. And dry macular degeneration may progress to wet macular degeneration, which can cause rapid vision loss if left untreated.

Prevention of dry macular degeneration

The following measures may help reduce your risk of developing dry macular degeneration:

• Have routine eye exams. Ask your eye doctor how often you need to undergo routine eye exams. A dilated eye exam can identify macular degeneration.
• Manage your other medical conditions. For example, if you have cardiovascular disease or high blood pressure, take your medication and follow your doctor’s instructions for controlling the condition.
• Don’t smoke. Smokers are more likely to develop macular degeneration than are nonsmokers. Ask your doctor for help to stop 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. Maintain a healthy weight by exercising regularly and controlling your diet.
• 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 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 of dry macular degeneration

Your doctor may diagnose your condition by reviewing your medical and family history and conducting a complete eye exam. He or she may also do several other tests, including:

• Examination of the back of your eye. Your eye doctor will put drops in your eyes to dilate them and use a special instrument to examine the back of your eye. He or she will look for a mottled appearance that’s caused by drusen — yellow deposits that form under the retina. People with macular degeneration often have many drusen.
• Test for defects in the center of your vision. During an eye examination, your eye doctor may use an Amsler grid to test for defects in the center of your vision. Macular degeneration may cause some of the straight lines in the grid to look faded, broken or distorted.
• Fluorescein angiography. During this test, your doctor injects a colored 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 abnormal blood vessel or retinal changes.
• Indocyanine green angiography. Like fluorescein angiography, this test uses an injected dye. It may be used to confirm the findings of a fluorescein angiography or 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 of retina thinning, thickening or swelling. These can be caused by fluid accumulations from leaking blood vessels in and under your retina.

Treatment of dry macular degeneration

Dry macular degeneration can’t be cured. If your condition is diagnosed early, you can take steps to help slow its progression, such as taking vitamin supplements, eating healthfully and not smoking.

Low vision rehabilitation

Age-related 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 necessary for driving an automobile, reading and recognizing people’s faces. It may be beneficial for you to work with a low vision rehabilitation specialist, 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, 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, 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 doctor for help to quit.
• Choose a healthy diet. The antioxidant vitamins in fruits and vegetables contribute to eye health. Kale, spinach, broccoli, peas and other vegetables have high levels of antioxidants, including lutein and zeaxanthin, which may benefit people with macular degeneration. Foods containing high levels of zinc may also be of particular value in patients 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 fats, such as olive oil. And research studies have shown that a diet high in omega-3 fatty acids, such as found in salmon, tuna and walnuts, may lower the risk for advanced 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 medication and follow your doctor’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. Maintain a healthy weight by exercising regularly and controlling your diet.
• 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 identify if your condition develops into wet macular degeneration, which can be treated with drugs.

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, the American Academy of Ophthalmology says ⁷⁾. Research shows 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)

Furthermore, the use of antioxidant vitamins (e.g., vitamin C, vitamin E), lutein, zeaxanthin, and zinc in an otherwise well-nourished population with intermediate age related macular degeneration has been demonstrated to reduce the progression toward more advanced stages of age related macular degeneration by approximately 25% at 5 years ⁸⁾, ⁹⁾.

However, the evidence doesn’t show benefit in these supplements for people with early-stage dry macular degeneration. In addition, high doses of vitamin E may increase the risk of heart failure and other complications. Ask your doctor if taking supplements is right for you.

Coping and support

These tips may help you cope with your changing vision:

• Ask your eye doctor to check your eyeglasses. If you wear contacts or glasses, be sure your prescription is up to date.
• 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 may also 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 may also add speech-output systems or other technologies to your computer.
• Use electronic reading aids and voice interface. Try large-print books, tablet computers and audio books. Some tablet and smartphone apps are designed to help people with low vision. And many of these devices now come with a voice recognition system, 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 may also 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. Make arrangements to 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.

Wet macular degeneration

Wet macular degeneration is a chronic eye disease that causes blurred vision or a blind spot in your visual field. It’s generally caused by abnormal blood vessels that leak fluid or blood into the macula. The macula is in the part of the retina responsible for central vision.

Wet macular degeneration is one of two types of age-related macular degeneration. The other type — dry macular degeneration — is more common and less severe. The wet type always begins as the dry type.

Early detection and treatment of wet macular degeneration may help reduce vision loss and, in some instances, recover vision.

Symptoms of wet macular degeneration

Wet macular degeneration symptoms usually appear suddenly and worsen rapidly. They may include:

• Visual distortions, such as straight lines seeming bent
• Reduced central vision in one or both eyes
• Decreased intensity or brightness of colors
• A well-defined blurry spot or blind spot in your field of vision
• A general haziness in your overall vision
• Abrupt onset and rapid worsening of symptoms

Macular degeneration doesn’t affect side (peripheral) vision, so it rarely causes total blindness.

Causes of wet macular degeneration

No one knows the exact cause of wet macular degeneration, but it develops in people who have had dry macular degeneration. Of all people with age-related macular degeneration, about 10 percent have the wet form.

Wet macular degeneration can develop in different ways:

• Vision loss caused by abnormal blood vessel growth. Sometimes abnormal new blood vessels grow from the choroid under and into the macula (choroidal neovascularization). The choroid is the layer of blood vessels between the retina and the outer, firm coat of the eye (sclera). These abnormal blood vessels may leak fluid or blood, interfering with the retina’s function.
• Vision loss caused by fluid buildup in the back of the eye. When fluid leaks from the choroid, it can collect between the choroid and a thin cell layer called the retinal pigment epithelium. This may cause a bump in the macula, resulting in vision loss.

Risk factors for wet macular degeneration

Factors that may increase your risk of macular degeneration include:

• Age. This disease is most common in people over 65.
• Family history. This disease has a hereditary component. Researchers have identified several genes related to developing the condition.
• Smoking. Smoking cigarettes or being regularly exposed to smoke significantly increases your risk of macular degeneration.
• Obesity. Research indicates that being obese increases the chance that early or intermediate macular degeneration will progress to a more severe form of the disease.
• Cardiovascular disease. If you have diseases that affect your heart and blood vessels, you may be at higher risk of macular degeneration.

Complications of wet macular degeneration

People whose wet macular degeneration has progressed to central vision loss may experience depression or visual hallucinations (Charles Bonnet syndrome).

Prevention of wet macular degeneration

The following measures may help reduce your risk of developing wet macular degeneration:

• Have routine eye exams. Ask your eye doctor how often you need to undergo routine eye exams. A dilated eye exam can identify macular degeneration. In between checkups, you can do a self-assessment of your vision using an Amsler grid.
• Manage your other medical conditions. For example, if you have cardiovascular disease or high blood pressure, take your medication and follow your doctor’s instructions for controlling the condition.
• Don’t smoke. Smokers are more likely to develop macular degeneration than are nonsmokers. Ask your doctor for help to stop 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. Maintain a healthy weight by exercising regularly and controlling your diet.
• Choose a healthy diet. Include fruits, leafy greens, nuts and fish high in omega-3 fatty acids, such as salmon.
• Take certain nutritional supplements. If you have intermediate or advanced macular degeneration, taking supplements with high levels of vitamins C and E, zinc and copper may reduce the risk of vision loss, the American Academy of Ophthalmology says. Ask your doctor if taking supplements is right for you.

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, the American Academy of Ophthalmology says ¹⁰⁾. Research shows 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)

Furthermore, the use of antioxidant vitamins (e.g., vitamin C, vitamin E), lutein, zeaxanthin, and zinc in an otherwise well-nourished population with intermediate age related macular degeneration has been demonstrated to reduce the progression toward more advanced stages of age related macular degeneration by approximately 25% at 5 years ¹¹⁾, ¹²⁾.

However, the evidence doesn’t show benefit in these supplements for people with early-stage dry macular degeneration. In addition, high doses of vitamin E may increase the risk of heart failure and other complications. Ask your doctor if taking supplements is right for you.

Diagnosis of wet macular degeneration

Your doctor will review your medical and family history and conduct a complete eye exam. To confirm a diagnosis of macular degeneration, he or she may do several other tests, including:

• Examination of the back of your eye. Your eye doctor will put drops in your eyes to dilate them and use a special instrument to examine the back of your eye. He or she will look for fluid or blood or a mottled appearance that’s caused by drusen. People with macular degeneration often have many drusen — yellow deposits that form under the retina.
• Test for defects in the center of your vision. During an eye exam, your eye doctor may use an Amsler grid to test for defects in your central vision. If you have macular degeneration, some of the straight lines in the grid will look faded, broken or distorted.
• Fluorescein angiography. During this test, your doctor injects a colored dye into a vein in your arm. The dye travels to and highlights the blood vessels in your eye. A special camera takes pictures as the dye travels through the blood vessels. The images will show if you have abnormal blood vessels or retinal changes.
• Indocyanine green angiography. Like fluorescein angiography, this test uses an injected dye. It may be used to confirm the findings of a fluorescein angiography or to identify specific types of macular degeneration.
• Optical coherence tomography. This noninvasive imaging test displays detailed cross-sections of the retina. It identifies areas of thinning, thickening or swelling. This test is also used to help monitor how the retina responds to macular degeneration treatments.

Treatment of wet macular degeneration

Treatments are available that may help slow disease progression, preserve existing vision and, if started early enough, recover some lost vision.

Medications to stop growth of abnormal blood vessels

Medications may help stop growth of new blood vessels by blocking the effects of growth signals the body sends to generate new blood vessels. These drugs are considered the first line treatment for all stages of wet macular degeneration.

Medications used to treat wet macular degeneration include:

• Bevacizumab (Avastin)
• Ranibizumab (Lucentis)
• Aflibercept (Eylea)

Your doctor injects these medications into the affected eye. You may need injections every four weeks to maintain the beneficial effect of the medication. In some instances, you may partially recover vision as the blood vessels shrink and the fluid under the retina absorbs, allowing retinal cells to regain some function.

Possible risks of eye injections include conjunctival hemorrhage, eye pain, floaters, increased eye pressure and eye inflammation. Some of these medications may increase the risk of stroke.

Using light to activate an injected medication (photodynamic therapy)

Photodynamic therapy is sometimes used to treat abnormal blood vessels at the center of your macula.

In this procedure, your doctor injects a drug called verteporfin (Visudyne) into a vein in your arm, which travels to blood vessels in your eye. Your doctor shines a focused light from a special laser to the abnormal blood vessels in your eye. This activates the drug, causing the abnormal blood vessels to close, which stops the leakage.

Photodynamic therapy may improve your vision and reduce the rate of vision loss. You may need repeated treatments over time, as the treated blood vessels may reopen.

After photodynamic therapy, you’ll need to avoid direct sunlight and bright lights until the drug has cleared your body, which may take a few days.

Using a laser to destroy abnormal blood vessels (photocoagulation)

During laser therapy, your doctor uses a high-energy laser beam to seal abnormal blood vessels under the macula. The laser causes scarring that can create a blind spot, but the procedure is used to stop the vessels from bleeding with the aim of minimizing further damage to the macula. Even with this treatment, blood vessels may regrow, requiring further treatment.

Few people who have wet macular degeneration are candidates for this treatment. It generally isn’t an option if you have abnormal blood vessels directly under the center of the macula. Also, the more damaged your macula is, the lower the likelihood of success.

Low vision rehabilitation

Age-related 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 necessary for driving, reading and recognizing people’s faces. It may be beneficial for you to work with 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.

Coping and support

Vision loss from macular degeneration can affect your ability to do things such as read, recognize faces and drive. These tips may help you cope with your changing vision:

• Ask your eye doctor to check your eyeglasses. If you wear contacts or glasses, be sure your prescription is up to date.
• 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 may also 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 may also add speech-output systems or other technologies to your computer.
• Use electronic reading aids and voice interface. Try large-print books, tablet computers and audio books. Some tablet and smartphone apps are designed to help people with low vision. And many of these devices now come with a voice recognition feature.
• 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 may also 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 a friend or family member to help, especially with night driving.
• Make arrangements to 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.

What causes macular degeneration

The cause of macular degeneration is not known. But it is more common in people who smoke, who are overweight, who eat an unhealthy diet or who have a condition that affects their blood vessels, like high cholesterol or diabetes.

Risk factors for macular degeneration

The main risk factors for the development of advanced age-related macular degeneration are increasing age, ethnicity, and genetics. Although a number of modifiable risk factors have been investigated, cigarette smoking is the main modifiable risk factor that has been consistently identified in numerous studies ¹³⁾. Importantly, it is essential to recognize that the associations found in observational studies that analyze risk factors should not be interpreted as cause and effect. Such associations may not necessarily translate into treatment recommendations, as there may be multiple confounding variables that are not accounted for in the studies.

Smoking, Hypertension, and Cardiovascular Disease

Smoking significantly increases the risk of age-related macular degeneration, and there appears to be a dose response relationship, because the relative risk increases with an increased number of pack-year exposure ¹⁴⁾. Smoking cessation is associated with a reduced risk of age-related macular degeneration progression; the risk of developing age-related macular degeneration in individuals who have not smoked for more than 20 years is comparable to the risk in nonsmokers ¹⁵⁾. Thus, smoking cessation is strongly recommended when advising patients, as it represents a key and important modifiable risk factor. A number of case-control and population-based studies have examined the relationship between age-related macular degeneration, hypertension, and other cardiovascular diseases. These studies have shown conflicting results ¹⁶⁾, ¹⁷⁾, ¹⁸⁾.

Levels of Antioxidants

Additional risk factors may include low systemic levels of antioxidants. Data from observational studies have been inconsistent in identifying low levels of plasma and dietary antioxidants of vitamins C and E, carotenoids (e.g., lutein, zeaxanthin), and zinc as risk factors for age-related macular degeneration ¹⁹⁾, ²⁰⁾. The original Age-Related Eye Disease Study (AREDS) results demonstrate a beneficial effect for the use of high-dose oral antioxidant vitamins (vitamins C, E, beta-carotene) and zinc supplementation in reducing progression of intermediate age-related macular degeneration or advanced age-related macular degeneration in the fellow eye to advanced age-related macular degeneration by 25% ²¹⁾. However, additional vitamin E supplementation above the AREDS levels should be avoided ²²⁾. Results of Age-Related Eye Disease Study 2 (AREDS2) support the replacement of beta-carotene (from the original AREDS) with lutein/zeaxanthin in the new AREDS2 supplements ²³⁾. Furthermore, elimination of the beta-carotene component may reduce the competitive absorption of the lutein/zeaxanthin. Importantly, removal of beta-carotene may also decrease the observed increased mortality in smokers, who were observed to have a higher incidence of lung cancer associated with the use of supplemental beta-carotene ²⁴⁾. Finally, AREDS2 demonstrated that there was no effect on the progression of age-related macular degeneration by either reducing the zinc dose (from 80 mg to 25 mg) or adding an omega-3 polyunsaturated fatty acid supplement (docosahexaenoic acid [DHA] and eicosapentaenoic acid [EPA]) ²⁵⁾.

Diet

Several studies have also identified an association between dietary fat and advanced age-related macular degeneration. Similar to the reports on risk factors for cardiovascular disease, a number of reports from population-based studies have demonstrated that a reduced risk of age-related macular degeneration is associated with higher dietary intake of foods rich in omega-3 long-chain polyunsaturated fatty acids, such as fish ²⁶⁾, ²⁷⁾, ²⁸⁾. In a nested cohort study from the original AREDS population of 1837 patients who were at moderate risk for progression, participants who reported the highest omega-3 intake (note that this was not in the form of a supplement) were 30% less likely to develop advanced age-related macular degeneration after 12 years ²⁹⁾. An increased risk of age-related macular degeneration was found in individuals who had a higher intake of saturated fats and cholesterol and in those with a higher body mass index ³⁰⁾. Despite this dietary association, AREDS2 failed to demonstrate a benefit from the use of DHA and EPA as oral supplements at the doses tested; both are omega-3 poly-unsaturated fatty acids ³¹⁾.

Aspirin

Recent observational studies have indicated a possible link between aspirin use and age-related macular degeneration. The Beaver Dam Eye Study reported two times the incidence of late macular degeneration in patients who used aspirin at least twice weekly for 10 years compared with those who used no aspirin ³²⁾. Other studies have shown a potential protective effect of aspirin against the development of age-related macular degeneration ³³⁾. In a meta-analysis of 10 studies including over 171,000 patients, the use of aspirin was not associated with an increased risk of age-related macular degeneration ³⁴⁾. In light of all of the available information on the subject of aspirin use and age-related macular degeneration, the current preferred practice is for patients who have been instructed to use aspirin by a physician to continue their aspirin therapy as prescribed.

Genetic Factors

Molecular genetic studies and epidemiologic studies have determined some of the genetic factors in age-related macular degeneration ³⁵⁾. Several studies published in 2005 identified a strong association of the complement factor H (CFH) Y402H polymorphism with a higher risk of age-related macular degeneration ³⁶⁾.

The CFH gene product is involved in regulation of the complement system through binding to factor C3b. This specific complement factor represents a key regulator of the innate immune system (as opposed to the adaptive immune system). An alteration of regulation that occurs as a result of modification at the C3b site leads to a defective regulation of the alternative complement pathway and results in an up-regulation of inflammation to host cells that are mediated by the membrane attack complex. Patients homozygous for the Y402H risk allele of CFH possess a 7.4-fold increased risk of age-related macular degeneration. The CFH gene is located on chromosome 1, in a region linked to age-related macular degeneration in multiple family studies ³⁷⁾. Studies report an association of a CFH variant (homozygous individuals) with other factors for the risk of progression to advanced age-related macular degeneration compared with noncarriers who lack these determinants ³⁸⁾. Other factors associated with abnormal complement variants and age-related macular degeneration progression include an elevated erythrocyte sedimentation rate, an elevated serum C-reactive protein, and smoking. Such findings support the combined pathogenic mechanisms for age-related macular degeneration progression that include an interplay of environmental factors, heredity, and inflammation.

The ARMS2/HtrA1 genes are in close linkage disequilibrium and, together, they are also strongly associated with age-related macular degeneration ³⁹⁾. The exact mechanism that explains this association has not been clearly determined.91 Other proposed genetic variants associated with age-related macular degeneration include a variant in the hepatic lipase (LIPC) gene and the rs3775291 variant in the toll-like receptor 3 (TLR3) gene ⁴⁰⁾. A combination of genes and other risk factors may dispose an individual to varying age-related macular degeneration risks more than any one variant taken in isolation ⁴¹⁾. A recent genome-wide association study has identified 19 loci, seven of which are newly described ⁴²⁾.

Age-related macular degeneration has a complex genetic background with similar phenotypes. Many genetic associations have been identified, some are protective, some are associated with disease progression, and others have been reported yet not confirmed and require further investigation.

In 2013, several authors proposed, based on a post hoc analysis of an AREDS subset, that genetic selection of subjects who would most benefit from nutritional supplementation should be used to guide therapy. Thus, the authors recommend using a personalized genetic testing approach to guide therapy in age-related macular degeneration ⁴³⁾.

An analysis of the AREDS population that included an additional 526 AREDS subjects, concluded that genetic testing does not provide benefits in managing nutritional supplements in this population ⁴⁴⁾.

Statistical experts found that there was bias in the data analysis used to support genetic testing, primarily based on the use of post hoc analysis methodology.102

One or more prospectively designed clinical trials will need to demonstrate the value of genetic testing in age-related macular degeneration. Thus, the routine use of genetic testing is not supported by the existing literature and is not recommended at this time.

Other Risk Factors

Other risk factors include an increase in the waist/hip ratio for men. This ratio has been demonstrated to increase the risk of both early and late age-related macular degeneration in men ⁴⁵⁾. Markers of inflammation, such as C-reactive protein, may be associated with a higher risk of age-related macular degeneration progression ⁴⁶⁾. Other possible factors that have been considered in various studies, with inconclusive findings, include hormonal status ⁴⁷⁾, sunlight exposure ⁴⁸⁾, alcohol use ⁴⁹⁾ and vitamins B and D status ⁵⁰⁾.

Macular degeneration stages and natural progression

Age-related macular degeneration has few symptoms in the early stages, so it is important to have your eyes examined regularly. If you are at risk for age-related macular degeneration because of age, family history, lifestyle, or some combination of these factors, you should not wait to experience changes in vision before getting checked for age-related macular degeneration.

Not everyone with early age-related macular degeneration will develop late age-related macular degeneration (late  or advanced AMD). For people who have early age-related macular degeneration in one eye and no signs of age-related macular degeneration in the other eye, about five percent will develop advanced age-related macular degeneration after 10 years. For people who have early age-related macular degeneration in both eyes, about 14 percent will develop late age-related macular degeneration in at least one eye after 10 years. With prompt detection of age-related macular degeneration, there are steps you can take to further reduce your risk of vision loss from late age-related macular degeneration.

If you have late age-related macular degeneration in one eye only, you may not notice any changes in your overall vision. With the other eye seeing clearly, you may still be able to drive, read, and see fine details. However, having late age-related macular degeneration in one eye means you are at increased risk for late age-related macular degeneration in your other eye. If you notice distortion or blurred vision, even if it doesn’t have much effect on your daily life, consult an eye care professional.

Early age-related macular degeneration

As defined by the Age-Related Eye Disease Study (AREDS), early age-related macular degeneration (category 2) is characterized by small drusen (<63 µm), few medium drusen (63–125 µm), and/or minimally detected or no pigment epithelial abnormalities in the macula. Patients in this category have a low risk of progressing to advanced age-related macular degeneration after 5 years in either eye ⁵¹⁾. More recently, the 10-year follow-up data has been reported from the AREDS study group on approximately 85% of the originally enrolled patients.120 In the group with a combination of small drusen or no drusen at baseline, approximately 15% developed large drusen at 10 years.

Intermediate age-related macular degeneration

Intermediate age-related macular degeneration (category 3) is a more critical distinction clinically because it places the individual at risk for progression to more advanced age-related macular degeneration. It has been defined by the AREDS as having extensive medium drusen (63–124 µm) or one or more large drusen (125 µm in diameter) in one or both eyes. The progression to advanced age-related macular degeneration at 5 years in this group is approximately 18% according to the original AREDS. However, for patients with large drusen in one eye, the rate of development of advanced age-related macular degeneration at 5 years is 6.3%, whereas the rate for patients with multiple bilateral large drusen increases to 26% at 5 years ⁵²⁾. In the 10-year follow-up study of AREDS, 37% of patients developed large drusen when medium drusen were present at baseline in one eye, and 71% developed large drusen when medium drusen were present in both eyes at baseline ⁵³⁾. When medium drusen were present at baseline, 14% progressed to advanced age-related macular degeneration at 10 years.

In 2005, a simplified severity scale was developed for assessing age-related macular degeneration risk progression that is based on two primary ophthalmoscopic features: one or more large drusen (≥125 µm) and the presence of pigmentary changes ⁵⁴⁾. Individuals with two affected eyes could then be given a five-step grading score of 0–4 (based on one point for each factor being present in each eye). The following scores (simplified severity scale) enable the clinician to communicate with the patient about his or her approximate 5-year risk for developing advanced age-related macular degeneration: 4 factors, 45%; 3 factors, 26%; 2 factors 9%; 1 factor 4%; and 0 factors 0.5%. The approximate 10-year risks were 71%, 53%, 28%, 8%, and 1.5%, respectively ⁵⁵⁾.

For patients without large drusen, the presence of intermediate drusen in both eyes is considered to represent one risk factor using this severity scale. Advanced age-related macular degeneration in one eye is counted as two risk factors. Often, such eyes also have large drusen and retinal pigment epithelium (RPE) pigmentary disturbances; they are considered to have four of four risk factors, the highest risk-level for progression of all patients with age-related macular degeneration (50% by 5 years and 71% by 10 years). Interestingly, an online age-related macular degeneration risk calculator that includes phenotype (simplified severity scale score described above) and demographic information (age, smoking, and family history of age-related macular degeneration) had excellent calibration and overall performance, whereas the addition of specific genetic analysis added little to the 9- to 10-year trend for the development of advanced age-related macular degeneration ⁵⁶⁾.

Reticular pseudodrusen (also referred to as subretinal drusenoid deposits) may be under-recognized. They are best imaged using fundus autofluorescence, infrared reflectance, and/or spectral domain optical coherence tomography, and they appear to represent a meaningful risk factor associated with progression to the geographic atrophy ⁵⁷⁾.

Advanced age-related macular degeneration (Late AMD)

Advanced age-related macular degeneration (category 4) as defined in the AREDS refers to either neovascular age-related macular degeneration (also called wet age-related macular degeneration) or geographic atrophy (also called dry age-related macular degeneration) involving the center of the macula. Visual acuity in one eye is affected in all category 4 patients. In the Beaver Dam Eye Study, approximately 22% of the fellow eyes of such patients developed neovascular changes or geographic atrophy involving the fovea over 5 years ⁵⁸⁾. In AREDS, for patients with advanced age-related macular degeneration in one eye, the risk of progression to an advanced stage in the fellow eye ranged from 35% to 50% at 5 years, depending largely on the phenotype in the better eye ⁵⁹⁾. In the Submacular Surgery Trial, these findings were also confirmed and further emphasize the value of the simple risk scale ⁶⁰⁾.

The phenotype of central geographic atrophy, the advanced form of non-neovascular age-related macular degeneration, will have one or more zones of well-demarcated RPE and/or choriocapillaris atrophy. Drusen and other pigmentary abnormalities may surround the atrophic areas. Severe visual acuity loss occurs less commonly and more slowly in patients with geographic atrophy than in patients with neovascular age-related macular degeneration. Nevertheless, geographic atrophy involving the foveal center causes approximately 10% of all age-related macular degeneration-related visual loss of 20/200 or worse ⁶¹⁾. Patients with geographic atrophy not necessarily involving the central fovea may have relatively good distance visual acuity yet manifest a substantially decreased ability to perform near visual tasks such as reading. Doubling of the visual angle in patients with geographic atrophy has been reported to occur in as many as 50% of patients over a 2-year period ⁶²⁾. Choroidal neovascularization also may occur.

Neovascular age-related macular degeneration is characterized angiographically as either classic, occult, predominantly classic, minimally classic, or mixed lesions. Serous and/or hemorrhagic detachment of the neurosensory retina or the RPE, and/or various stages of an elevated, fibrovascular disciform scar, may also occur.

In the Macular Photocoagulation Study, classification of neovascular age-related macular degeneration with choroidal neovascularization was based on fluorescein angiography. Classic choroidal neovascularization (Gass Type 2 membrane) is defined as a well-demarcated hyperfluorescence in the early phase of the angiogram, with progressive leakage of dye into the overlying subneurosensory retinal space during the late phases of the angiogram. Occult choroidal neovascularization (Gass Type 1 membrane) is characterized by either a fibrovascular pigment epithelial detachment (PED) or late leakage of undetermined source. A fibrovascular PED is an irregular elevation of the RPE that has accompanying stippled heterofluorescence or even hypofluorescence early in the angiogram, with progressive late leakage in the later stages of the angiogram. An occult lesion with late leakage of undetermined source is not elevated yet shows a similar pattern of late leakage (usually after 1 minute). Other clinical subtypes or features of neovascular age-related macular degeneration may include the following:

• Retinal pigment epithelial detachment (PED)
• Idiopathic polypoidal choroidal vasculopathy ⁶³⁾, which should be suspected in patients with orange polypoid lesions and especially in patients of African or Asian descent. The lesions are often located in the peripapillary region. An indocyanine green (ICG) angiogram is often useful in confirming the diagnosis.
• Retinal angiomatous proliferation (RAP) ⁶⁴⁾

Macular degeneration symptoms

The main symptom of macular degeneration is that you can’t focus on close objects. Therefore, you might:

• have blurred vision or blind spots
• have trouble reading small print
• need a brighter light to do close work or read
• have problems judging distances
• have difficulty recognizing faces
• think colors seems less bright
• see straight lines as wavy.

Macular degeneration diagnosis

During an eye exam, your ophthalmologist may ask you to look at an Amsler grid. This grid helps you notice any blurry or blank spots in your field of vision. Your ophthalmologist will also look inside your eye through a special lens. He or she can see if there are changes in the retina and macula.

The early and intermediate stages of age related macular degeneration usually start without symptoms. Only a comprehensive dilated eye exam can detect age related macular degeneration.

The eye exam may include the following:

• Visual acuity test. This eye chart measures how well you see at distances.
• Dilated eye exam. Your eye care professional places drops in your eyes to widen or dilate the pupils. This provides a better view of the back of your eye. Using a special magnifying lens, he or she then looks at your retina and optic nerve for signs of AMD and other eye problems.
• Amsler grid. Your eye care professional also may ask you to look at an Amsler grid. Changes in your central vision may cause the lines in the grid to disappear or appear wavy, a sign of AMD.
• Fluorescein angiogram. In this test, which is performed by an ophthalmologist, a fluorescent dye is injected into your arm. Pictures are taken as the dye passes through the blood vessels in your eye. This makes it possible to see leaking blood vessels, which occur in a severe, rapidly progressive type of AMD. In rare cases, complications to the injection can arise, from nausea to more severe allergic reactions.
• Optical coherence tomography. You have probably heard of ultrasound, which uses sound waves to capture images of living tissues. Optical coherence tomography is similar except that it uses light waves, and can achieve very high-resolution images of any tissues that can be penetrated by light—such as the eyes. After your eyes are dilated, you’ll be asked to place your head on a chin rest and hold still for several seconds while the images are obtained. The light beam is painless.

During the exam, your eye care professional will look for drusen, which are yellow deposits beneath the retina. Most people develop some very small drusen as a normal part of aging. The presence of medium-to-large drusen may indicate that you have AMD.

Another sign of age related macular degeneration is the appearance of pigmentary changes under the retina. In addition to the pigmented cells in the iris (the colored part of the eye), there are pigmented cells beneath the retina. As these cells break down and release their pigment, your eye care professional may see dark clumps of released pigment and later, areas that are less pigmented. These changes will not affect your eye color.

Macular degeneration treatment

There is no cure for macular degeneration, so treatment is about preventing further loss of eyesight and maintaining independence for as long as possible. It is important to prevent more damage. Medication, surgery and laser therapy might also help.

Special vitamin supplements are sometimes prescribed for macular degeneration.

Macular degeneration vitamins

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, the American Academy of Ophthalmology says ⁶⁵⁾.

Research based on AREDS ⁶⁶⁾ and AREDS2 ⁶⁷⁾ shows 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)

If you have intermediate or late AMD, you might benefit from taking supplements containing these ingredients. But first, be sure to review and compare the labels. Many supplements have different ingredients, or different doses, from those tested in the Age-Related Eye Disease Study (AREDS) trials ⁶⁸⁾, ⁶⁹⁾. Also, consult your doctor or eye care professional about which supplement, if any, is right for you. For example, if you smoke regularly, or used to, your doctor may recommend that you avoid supplements containing beta-carotene. Remember that the AREDS formulation is not a cure. It does not help people with early AMD, and will not restore vision already lost from AMD. But it may delay the onset of late AMD. It also may help slow vision loss in people who already have late AMD.

Even if you take a daily multivitamin, you should consider taking an AREDS supplement if you are at risk for late AMD. The formulations tested in the AREDS trials contain much higher doses of vitamins and minerals than what is found in multivitamins. Tell your doctor or eye care professional about any multivitamins you are taking when you are discussing possible AREDS formulations.

The original Age-Related Eye Disease Study (AREDS) results demonstrate a beneficial effect for the use of high-dose oral antioxidant vitamins (vitamins C, E, beta-carotene) and zinc supplementation in reducing progression of intermediate age-related macular degeneration or advanced age-related macular degeneration in the fellow eye to advanced age-related macular degeneration by 25% ⁷⁰⁾. However, additional vitamin E supplementation above the AREDS levels should be avoided ⁷¹⁾. Results of Age-Related Eye Disease Study 2 (AREDS2) support the replacement of beta-carotene (from the original AREDS) with lutein/zeaxanthin in the new AREDS2 supplements ⁷²⁾. Furthermore, elimination of the beta-carotene component may reduce the competitive absorption of the lutein/zeaxanthin. Importantly, removal of beta-carotene may also decrease the observed increased mortality in smokers, who were observed to have a higher incidence of lung cancer associated with the use of supplemental beta-carotene ⁷³⁾. Finally, AREDS2 demonstrated that there was no effect on the progression of age-related macular degeneration by either reducing the zinc dose (from 80 mg to 25 mg) or adding an omega-3 polyunsaturated fatty acid supplement (docosahexaenoic acid [DHA] and eicosapentaenoic acid [EPA]) ⁷⁴⁾.

Furthermore, the use of antioxidant vitamins (e.g., vitamin C, vitamin E), lutein, zeaxanthin, and zinc in an otherwise well-nourished population with intermediate age related macular degeneration has been demonstrated to reduce the progression toward more advanced stages of age related macular degeneration by approximately 25% at 5 years ⁷⁵⁾, ⁷⁶⁾.

However, the evidence doesn’t show benefit in these supplements for people with early-stage dry macular degeneration. In addition, high doses of vitamin E may increase the risk of heart failure and other complications. Ask your doctor if taking supplements is right for you.