Home Health Topics What Is Macular Degeneration? Symptoms, Causes, Diagnosis, Treatment, and Prevention

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What Is Macular Degeneration? Symptoms, Causes, Diagnosis, Treatment, and Prevention

July 14, 2020

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Signs and Symptoms of Macular Degeneration

Macular degeneration doesn’t cause total blindness because it doesn’t affect peripheral vision. However, it can significantly interfere with daily activities — such as the ability to drive, read, write, cook, do certain chores, or recognize faces or colors.

It's also possible to have macular degeneration in only one eye, or to have a more severe form of the condition in one eye than the other.

The basic symptoms of macular degeneration are:

Reduced or distorted central vision in one or both eyes
Reduced ability to see or differentiate colors
A blind or blurry spot in your field of vision
General haziness in your overall vision

Visit your eye doctor if you notice changes in your central vision, or in your ability to see colors and fine detail — especially if you’re 50 or older.

As macular degeneration progresses, the blurred area near the center of your vision may grow larger, or you may develop blank spots in your central vision.

The initial symptoms of macular degeneration are not painful; and sometimes, when the condition begins in one eye, the stronger eye compensates, so you may not immediately notice changes in vision.

The condition has few symptoms in the early stages, so it’s important to have your eyes examined regularly. An eye doctor might be able to see signs before symptoms appear — one reason why regular eye exams are vital for early diagnosis.

Stages of Macular Degeneration

Although macular degeneration in general, and AMD in particular, progresses more rapidly in some people than in others, there are three general stages:

Early AMD

In this presymptomatic stage, your macula develops medium-sized drusen (about the width of a human hair), but you may not notice any vision loss.

The drusen will be noticeable in a routine eye exam, according to the BrightFocus Foundation.

How to Manage and Monitor Your Macular Degeneration

Intermediate AMD

In this stage, your macula develops larger drusen, and you may have pigment changes in your retina. You may or may not experience some vision loss, but the changes in your retina will be detectable during an eye exam.

Late AMD

In this stage, you develop medium to large drusen in your macula and, as a result, noticeable vision loss.

Types of Macular Degeneration

Age-related macular degeneration comes in two forms: dry (also known as geographic atrophy) and wet (known as neovascular, or abnormal blood vessel growth).

Dry Macular Degeneration

Dry AMD, which accounts for about 90 percent of macular degeneration cases and is most common in people over 60,is a type of late-stage AMD.

In people who have dry AMD, the light-sensitive cells in the macula and the supportive tissue beneath it gradually break down, resulting in vision loss. And while dry AMD typically affects both eyes, if it impacts only one eye, you may not notice any vision changes because your healthy eye may compensate for the affected eye, notes the BrightFocus Foundation.

What Is Dry Macular Degeneration?

Wet Macular Degeneration

Dry AMD can progress to wet macular degeneration, which is less common but often a more severe and rapidly progressing type of late AMD. Of all people with AMD, only about 10 percent have the wet form.

Stargardt Disease

A third form of macular degeneration is known as Stargardt disease, named for the German ophthalmologist Karl Stargardt, who reported the first known case of the disease in 1901. Unlike the first two types, it affects children and teens, and is the most common form of inherited juvenile macular degeneration, with about 30,000 cases in the United States, per the AMDF.

How Is Macular Degeneration Diagnosed?

To confirm a diagnosis of macular degeneration, your eye doctor may perform several tests, including:

A basic eye exam
Amsler grid test
Fluorescein angiography
Optical coherence tomography

Basic Eye Examination

An examination of the back of your eye will most likely come first. After dilating your pupils with eye drops, your doctor will check for damage caused by drusen, or accumulated fluids.

Amsler Grid

To check for defects in the center of your vision, your doctor may use a test called an Amsler grid. If you have macular degeneration, some of the straight lines in the Amsler grid will look faded, broken, or distorted, according to Mayo Clinic.

Fluorescein Angiography

In fluorescein angiography — also called indocyanine green angiography — your doctor will inject a colored dye into a vein in your arm that will travel to the blood vessels in your eye, highlighting them, then use a special camera to take pictures as the dye travels through your blood vessels to check for abnormalities or retinal changes.

Optical Coherence Tomography

Optical coherence tomography (OCT) is a noninvasive test that produces detailed cross-sectional images of your retina, allowing your doctor to spot areas of thinning, thickening, or swelling. This test is also used to help monitor how the retina responds to treatment.

Genetic testing may be used to identify young people at risk for Stargardt disease; eventually, scientists hope that a gene therapy approach might work to replace the defective genes that cause Stargardt or AMD, though this is likely several years into the future.

Prognosis of Macular Degeneration

If you develop early AMD, you may not progress to late AMD. Research shows that people with early AMD in one eye, and no signs of AMD in the other eye, have only a 5 percent chance of progressing to late AMD after 10 years.

If you have early AMD in both eyes, there is a 14 percent chance of developing late AMD in at least one eye after 10 years.

Having late AMD in one eye does put you at increased risk for late AMD in your other eye. Having the condition in both eyes will likely impact your ability to read and perform other activities.

While there is currently no cure for any form of macular degeneration, available treatments may prevent severe vision loss or slow the progression of the condition.

Treatment and Medication Options for Macular Degeneration

Although there’s no cure for macular degeneration, several different approaches may be used to treat the condition and slow its progression.

For intermediate dry macular degeneration, a daily combination of vitamins and nutritional supplements has been shown to slow progression.

AREDS and AREDS2 formulas (like Preservision AREDS2) are nutritional supplements that reduce the risk of a person progressing to advanced age-related macular degeneration. The formulas are based on the National Eye Institute (NEI) funded Age-Related Eye Diseases Studies (where the names AREDS and AREDS2 come from).

Medication for Macular Degeneration

If you have wet macular degeneration, certain medications can stop growth of new, abnormal blood vessels in the macula. These drugs are called anti-vascular endothelial growth factor (anti-VEGF) therapies, and include Avastin (bevacizumab), Lucentis (ranibizumab), and Eylea (aflibercept).

The treatment, which may require repeated, monthly injections, has been shown to restore vision in some people with AMD, and prevent blindness in up to 90 percent of those who receive it.

If the treatment is effective, you may recover some lost vision as the blood vessels shrink and the fluid under the retina is absorbed.

Potential side effects include:

Serious eye infections that may cause eye pain, light sensitivity, and vision changes
Increased intraocular pressure, which can lead to glaucoma
Retinal detachment
Floaters (or shapes that appear in your field of vision)

Medical and Surgical Procedures for Macular Degeneration

A couple of noninvasive procedures may help with some forms of AMD:

Photodynamic therapy uses a special light to activate a drug that can repair leaky blood vessels and prevent further damage to the macula. Multiple treatments may be necessary, because treated blood vessels can reopen, notes Johns Hopkins Medicine.

Laser photocoagulation is an older procedure in which a laser is used to seal off abnormal blood vessels, so that they can regrow.Few people with wet macular degeneration are candidates for this treatment, however, because abnormal blood vessels often develop directly under the center of the macula.

Alternative and Complementary Therapies

The large study by the National Eye Institute called AREDS — the Age-Related Eye Disease Study — found that some people with AMD can reduce their risk for wet AMD and vision loss by taking vitamins C, E, beta-carotene, zinc, and copper supplements.

The second study, AREDS2, showed that substituting lutein and zeaxanthin for beta-carotene can produce similar results in active cigarette smokers for whom beta-carotene could increase the risk of lung cancer.

However, excessive amounts of vitamin A — normally beneficial for visual health — can be toxic in people with Stargardt disease because their eyes can’t metabolize the nutrient.

In addition to diet and nutrition, many people benefit from seeing a healthcare professional who can help find ways to adapt to changing vision, using special eyewear and other assistive devices. A low-vision rehabilitation specialist, occupational therapist, eye doctor, or other healthcare professional trained in this area can direct you to rehabilitation resources and support groups, notes VisionAware.

Learn More About Treatment for Age-Related Macular Degeneration

Prevention of Macular Degeneration

Certain steps can reduce your risk of developing macular degeneration and help manage your condition. This includes getting routine dilated-eye exams.

Make it a priority to quit smoking, since smokers are more likely to develop macular degeneration.

Regular exercise and maintaining a healthy weight is also important, as is a diet rich in antioxidants and nutrients, typically found in vegetables and fruits, along with fish.

In addition, the AREDS-AREDS2 diet may help slow progression of AMD and delay or even reduce vision loss. Eating a diet full of green leafy vegetables, oily fish (containing omega-3 fatty acids), and carrots for carotenoids, as well as a Mediterranean Diet emphasizing vegetables, whole grains, fish, fruit, red wine, olive oil, and some dairy, is linked with lower rates of wet AMD, according to a study published in March 2019 in the journal Ophthalmology.

Avoiding ultraviolet and blue light, which is understood to be harmful to the retina, may also have a protective effect, notes AMDF.

Finally, wearing proper eye protection when outdoors can help you maintain eye health and reduce your risk for AMD.

Research and Statistics: How Many People Have Macular Degeneration?

Approximately 11 million people in the United States are living with macular degeneration, research suggests. That number is expected to double by 2050, due to the aging population.

In addition, an estimated 30,000 young people between 6 and 20 years of age in the United State have been diagnosed with Stargardt disease, an inherited form of macular degeneration that can start in childhood, according to Foundation Fighting Blindness.

Related Conditions of Macular Degeneration

Macular degeneration is the leading cause of vision loss in people ages 50 and older. However, there are other eye conditions to watch out for as you age.

Cataracts

According to the National Eye Institute, more than 50 percent of adults over 80 years of age develop cataracts, which are the most common cause of blindness in the world, per the National Eye Institute.Cataracts involve the clouding of the lens of the eye. Some people develop cataracts as a result of smoking or as a side effect of diabetes.

Cataracts aren't preventable, but they’re treatable with surgery.

Diabetic Retinopathy

Diabetic retinopathy is a chronic condition caused by diabetes as a result of damage to the blood vessels of the light-sensitive area at the back of the eyes. At first the condition causes minor vision problems, such as difficulty seeing at a distance.

However, as diabetes progresses retinopathy does as well, and may eventually lead to blindness. Still, diabetic retinopathy can be managed with laser treatments and some patients may have vitrectomy surgery.

Glaucoma

Glaucoma is a collection of eye conditions that can eventually damage the optic nerve — usually as a result of increased pressure in the eye, or intraocular pressure. Glaucoma can lead to loss of peripheral vision and, over time, cause total blindness if it’s left untreated. It can be prevented by lowering intraocular pressure with topical eye drops or surgery.

Presbyopia

At about age 40, many adults develop a condition called presbyopia, which affects both near and distance vision. The condition can make daily activities — such as reading and working at the computer — challenging but, for most people, eyeglasses or contact lenses designed to address it can help.

Dry Eye

Older adults are also more prone to an eye condition called dry eye, which is caused by low tear production. People with dry eye don’t produce sufficient tears to keep their eyes well lubricated, causing discomfort, including redness, stinging, and burning, all of which may impact vision. There isn't a cure for dry eye, but saline lubricating drops or artificial tears can help to relieve some of the symptoms. Some prescription drugs can also help manage the condition.

In general, older adults with vision problems are 200 percent more likely to be involved in motor vehicle accidents, so it's important to be aware of how aging may affect your vision.

Additional reporting by Deborah Shapiro.

Editorial Sources and Fact-Checking

What Is Macular Degeneration? American Macular Degeneration Foundation.
Boyd K, Turbert D. Eye Anatomy: Parts of the Eye and How We See. American Academy of Ophthalmology. March 9, 2021.
Pennington KL, DeAngelis MM. Epidemiology of Age-Related Macular Degeneration (AMD): Associations With Cardiovascular Disease Phenotypes and Lipid Factors (PDF). Eye and Vision. December 22, 2016
Age-Related Macular Degeneration (AMD) Data and Statistics. National Eye Institute. July 17, 2019.
Dry Macular Degeneration. BrightFocus Foundation.
View How Macular Degeneration May Affect Vision. BrightFocus Foundation. October 29, 2018.
Stargardt Disease Defined. The American Macular Degeneration Foundation.
Stargardt Disease. Foundation Fighting Blindness.
Boyd K. Stargardt Disease Symptoms. American Academy of Ophthalmology. April 23, 2020.
What Is Stargardt Disease? National Eye Institute. July 10, 2019.
García-Layana A, Cabrera-López F, García-Arumí J, et al. Early and Intermediate Age-Related Macular Degeneration: Update and Clinical Review. Clinical Interventions in Aging. October 3, 2017.
Risk Factors for Macular Degeneration. American Macular Degeneration Foundation.
Wet Macular Degeneration — Symptoms and Causes. Mayo Clinic. December 11, 2020.
Wet Macular Degeneration — Diagnosis and Treatment. Mayo Clinic. December 11, 2020.
Age-Related Macular Degeneration (AMD): Overview. InformedHealth.org. May 3, 2018
Boyd K. How Is AMD Diagnosed and Treated? The American Academy of Ophthalmology. February 28, 2020.
Photodynamic Therapy for Age-Related Macular Degeneration. Johns Hopkins Medicine.
Macular Degeneration Treatments. American Macular Degeneration Foundation.
Age-Related Macular Degeneration (AMD). Johns Hopkins Medicine.
Age Related Eye Disease Studies AREDS/AREDS2. National Eye Institute. April 13, 2020.
Duffy MA. What Is Low Vision? VisionAware.
Ultra-Violet and Blue Light Aggravate Macular Degeneration. American Macular Degeneration Foundation.
Cimarolli VR, Casten RJ, Rovner BW, et al. Anxiety and Depression in Patients With Advanced Macular Degeneration: Current Perspectives. Clinical Ophthalmology. December 30, 2015.
Charles Bonnet Syndrome. Macular Society.
Fisher DE, Klein BEK, Wong TY, et al. Incidence of Age-Related Macular Degeneration in a Multi-Ethnic United States Population: The Multi-Ethnic Study of Atherosclerosis. Ophthalmology. February 16, 2016.
Merle BMJ, Colijn JM, Cougnard-Grégoire A, et al. Mediterranean Diet and Incidence of Advanced Age-Related Macular Degeneration. Ophthalmology. March 1, 2019.
Cataracts. National Eye Institute. August 3, 2019.