Age-Related Macular Degeneration

 

Age-related Macular Degeneration

Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the top cause of vision loss in people over 50. Dry AMD can lead to gradual visual impairment, while wet AMD tends to cause rapid vision loss. People with AMD lose their central vision and can’t see things directly in front of them. AMD doesn’t cause total blindness, but it can greatly affect everyday life.

OVERVIEW

What is age-related macular degeneration?

Age-related macular degeneration (AMD) is an eye disease that affects central vision. People with AMD can’t see people or things directly in front of them. This common age-related eye problem occurs in people over the age of 50. AMD affects the macula, the back part of the retina that controls central vision. People with AMD aren’t completely blind. Their peripheral vision (ability to see things off to the sides) is fine.

Does age-related macular degeneration affect both eyes?

AMD may develop in one eye or both eyes.

How common is age-related macular degeneration?

More than 10 million Americans have macular degeneration. It’s the leading cause of vision loss. The disease affects more people than cataracts and glaucoma combined.

Who might get age-related macular degeneration?

As the name implies, age-related macular degeneration is more likely to occur as you get older. Other risk factors include:

• Family history of AMD.
• Being overweight.
• Smoking.
• High blood pressure (hypertension).
• A diet high in saturated fats.
• Being of European descent.

What are the types of age-related macular degeneration?

There are two types of AMD:

• Dry (atrophic): Up to 90% of people with macular degeneration have the dry form. It develops when tiny yellow protein deposits called drusen form under the macula. The built-up deposits dry and thin the macula. Vision loss with the dry form tends to occur gradually. Most people don’t completely lose central vision. Rarely, the dry form leads to the wet form.
• Wet (exudative): This condition occurs when abnormal blood vessels develop under the retina and macula. The blood vessels leak blood and fluid (a condition called choroidal neovascularization, or CNV). Because of fluid buildup, a bulge forms in the macula. You may see dark spots in your center of vision. About 15% of people with macular degeneration have the wet form. This type is more severe. It can quickly lead to total loss of central vision.

What are the stages of age-related macular degeneration?

AMD occurs in three stages. Often, symptoms like vision loss aren’t evident until the late stage.

• Early: The macula changes, but vision isn’t affected.
• Intermediate: Vision may get blurry or wavy.
• Late (advanced): Central vision fails completely.

SYMPTOMS AND CAUSES

What causes age-related macular degeneration?

AMD is a type of inherited eye disease. However, the disease also develops in people with no family history of the disease. AMD occurs when the macula at the back of the eye starts to deteriorate for unknown reasons.

What are the symptoms of age-related macular degeneration?

The macula helps send images from the eye’s optic nerve to the brain. If you have a damaged macula, your brain can’t understand or read the images that your eyes see.

Many people with age-related macular degeneration don’t have symptoms until the disease progresses. You may experience:

• Blurred (low) vision.
• Blank or dark spots in your field of vision.
• The appearance of waves or curves in straight lines.

DIAGNOSIS AND TESTS

How is age-related macular degeneration diagnosed?

Because AMD rarely causes symptoms in its early stages, annual eye examinations are key to detecting the disease and starting treatments when they’re most effective. During an eye exam, your eye healthcare provider checks for changes to the retina and macula. You may get one or more of these tests:

• Visual field test: An Amsler grid has a grid of straight lines with a large dot in the center. Your healthcare provider may ask you to identify lines or sections on the grid that look blurry, wavy or broken. A lot of distortion may indicate that you have AMD or the disease is worsening. You can use this visual field test at home to monitor your vision.
• Dilated eye exam: Eye drops dilate, or widen, your pupils. Once your eyes are dilated, your healthcare provider uses a special lens to look inside your eyes.
• Fluorescein angiography: Your healthcare provider injects a yellow dye called fluorescein into a vein in your arm. A special camera tracks the dye as it travels through blood vessels in the eye. The photos can reveal any leakage under the macula.
• Optical coherence tomography (OCT): This imaging machine takes detailed images of the back of the eye, including the retina and macula. Optical coherence tomography isn’t invasive or painful. You simply look into a lens while the machine takes pictures.
• Optical coherence tomography angiography (OCTA): This diagnostic tool uses laser light reflection (instead of fluorescein dye) and the OCT scanning device. It takes just a few moments and produces 3D images of blood flow through the eye.

MANAGEMENT AND TREATMENT

How is age-related macular degeneration managed or treated?

AMD isn’t curable. Starting treatments early can slow disease progression and reduce the severity of symptoms. Even with successful treatments, AMD symptoms often return. Depending on the disease type, treatments include:

• Nutritional supplements: The Age-Related Eye Disease Study (AREDS) found that a combination of vitamins and minerals may slow the progression of dry AMD. AREDS supplements include vitamin C, vitamin E, lutein, zinc, copper, zeaxanthin and beta carotene. (Smokers shouldn’t take beta carotene because it raises the risk of lung cancer.)
• Antivascular endothelial growth factor (anti-VEGF): This treatment for wet AMD blocks the production of VEGF, a protein that produces new blood vessels. Your eye healthcare provider injects anti-VEGF into a numbed eye. The drug slows or stops blood vessel development. This treatment sometimes improves vision.
• Photodynamic therapy (PDT): During photodynamic therapy, your eye healthcare provider uses a combination of an injectable light-sensitive drug and a laser to destroy extra blood vessels in the eye. Your provider may combine PDT with anti-VEGF.

What are age-related macular degeneration treatment side effects or risks?

Treatments for wet AMD carry some risk of complications including:

• Eye infection.
• Retinal detachment.
• Structural eye damage.
• Faster onset of cataracts.
• Severe vision loss.

What are the complications of age-related macular degeneration?

Losing your central vision can make it challenging to do certain tasks. Depending on the extent of vision impairment, you may not be able to read well, recognize faces, drive, cook or do home repairs. If AMD is severe, you may be considered legally blind. These changes can lead to depression and anxiety. Some people with AMD experience Charles Bonnet syndrome, a condition that causes visual hallucinations.

PREVENTION

How can I prevent age-related macular degeneration?

You can take these steps to lower your risk of AMD:

• Quit smoking.
• Lose weight.
• Stay physically active.
• Maintain healthy blood pressure and cholesterol levels.
• Eat a healthy diet.

OUTLOOK / PROGNOSIS

What is the prognosis (outlook) for people with age-related macular degeneration?

Not everyone who has AMD experiences significant vision loss. With dry AMD, vision loss can happen slowly and take a long time to occur. Because the condition can affect just one eye, you may not notice any change in vision. Sometimes, vision loss is so severe that you’re considered legally blind. To see better, you might:

• Wear eyeglasses or contact lenses.
• Use brighter lights at home or work.
• Read with a magnifying device.

LIVING WITH

When should I call my healthcare provider?

You should call your healthcare provider if you have age-related macular degeneration and experience:

• Painful eye inflammation (iritis or uveitis) and sensitivity to light (photophobia).
• Eye pressure.
• Eye floaters or flashers.

What questions should I ask my healthcare provider?

If you have age-related macular degeneration, you may want to ask your healthcare provider:

• Why did I get AMD?
• What type of AMD do I have?
• What is the best treatment for the type of AMD I have?
• What lifestyle changes can I make to protect my vision?
• Are there any treatment risks or side effects?
• Is my family at risk for developing AMD? If so, what steps can they take to protect their vision?
• Should I watch for signs of complications?