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What You Need to Know About Macular Degeneration

The leading cause of severe and permanent vision loss among Americans aged 50 and older.

Your eyes work closely with your brain to help you see, and any interruptions in the circuit could spell trouble for your vision.

At the most basic level, the retina, a layer of tissue in the back of the eye, is responsible for capturing the light we see and sending it through the optic nerve to the brain, where the images we see are processed. But what happens when a portion of the retina—more specifically, the macula—doesn’t work as it should? This is known as macular degeneration, and is the leading cause of irreversible impairment of close-up vision—responsible for reading—among people 65 and older. 

Macular degeneration affects the center of a person’s vision—typically the area of sharpest vision—and destroys the ability to see objects clearly. Peripheral vision is not affected by macular degeneration. In early cases, vision may become blurred, and can progress to complete loss of sharp vision in those with advanced cases. Those with severe macular degeneration are considered legally blind.  

Types of Macular Degeneration

Macular degeneration develops in two forms: wet and dry. A majority of cases—between 85 and 90 percent—are dry. Dry macular degeneration is categorized by the breakdown of the macula and the supportive tissue. Dry macular degeneration may begin in one eye before affecting both, and, over time, may affect a person’s ability to read and recognize faces. Other symptoms include hazy vision and the need for bright lights to see clearly. Dry macular degeneration doesn’t always lead to complete loss of vision, however.  

Although less common, wet macular degeneration affects between 10 and 15 percent of those with the condition. This form of the disease begins like dry macular degeneration. In later stages, abnormal blood vessels behind the retina leak blood or fluid into the macula. This form of macular degeneration happens more suddenly, and can be more severe. Symptoms of wet macular degeneration include distorted vision, dark spots in your vision and the inability to view colors as brightly.   

Stages of the Disease

Macular degeneration progresses over time. There are three stages: early, intermediate and late. These stages are categorized by the size and number of drusen, fatty, yellow deposits beneath the retina. Although drusen don’t cause macular degeneration, the presence of these deposits ups your risk for the condition.   

Early: Vision loss is unlikely during the early stage of macular degeneration, a period where drusen are about the width of a human hair. Drusen are detected and measured during an eye exam, making regular examinations important.    

Intermediate: By this point, drusen are large and there may be changes in the pigment of the retina. The occurrence of both are possible. These changes cannot be detected with the naked eye—an exam is necessary. Although vision loss during the intermediate stage is possible, it may not even be noticeable.  

Late: During the later stages of macular degeneration, vision loss becomes apparent. This loss of sight is caused in one of two ways: the deterioration the macula and surrounding tissue (dry) or leakage of abnormal blood vessels into the macula (wet).

Causes and Risk Factors

There is no definitive cause of macular degeneration, but experts believe a combination of environmental and genetic factors are to blame. Macular degeneration is more common among older adults and is more common among Caucasians than members of the Hispanic or African American population. In 2010, Caucasians comprised nearly 90 percent of macular degeneration cases. A family history of the condition also ups your risk.

Your genes aren’t entirely to blame, however. Smoking, obesity and cardiovascular disease have also been linked to a higher risk of macular degeneration.     

Diagnostic Process

Macular degeneration is diagnosed with an eye exam. Your doctor will likely identify any changes to the retina or macula, including the appearance of drusen and changes in pigmentation. Through a series of procedures, your ophthalmologist will also look for the presence of abnormal blood vessels beneath the retina. The presence of these abnormalities may warrant a diagnosis of macular degeneration.  

Treatment and Prevention Options

There is no cure for macular degeneration, and vision loss can’t be restored with treatment. Lifestyle changes, vitamins, injections and surgery may be possible treatment options, depending on the severity of the condition.

Certain lifestyle changes, like enjoying a nutritious diet rich in leafy greens and fatty fish, kicking your smoking habit and getting more exercise may prevent macular degeneration and could help slow the progression of the disease.

The Age-Related Eye Disease Studies (AREDS) found certain vitamin supplements—including vitamins C and E, zinc and copper—may slow the progression of the condition in those with intermediate and late stage macular degeneration. But don’t go running to the pharmacy before speaking with your doctor.

There are other treatment options for wet macular degeneration, such as injections and laser surgery or therapy. Although these treatment options won’t cure the condition, they may prevent further vision loss, by stopping the leakage from abnormal blood vessels.

Drugs that prevent the growth of abnormal blood vessels may be injected directly into the eye over the course of several months. Varying types of lasers may also be used to close the openings of abnormal blood vessels to prevent further leakage into the retina. Laser treatments are less common than other treatment options, and may result in some permanent damage to healthy tissue.

Not all treatment options are safe for everyone, but low vision rehabilitation may be beneficial to many. Macular degeneration generally doesn’t cause total blindness, but it can diminish your ability to do things like drive and read. Your eye doctor, rehabilitation specialist and occupational therapist can help you find ways to live with your changing vision. 

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