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What’s the Difference Between Wet and Dry AMD?

Learn about the two different types of age-related macular degeneration.

What’s the Difference Between Wet and Dry AMD?

Age-related macular degeneration—commonly abbreviated as AMD—is the leading cause of vision loss and blindness for elderly people in the United States and many other places in the world.

The type of vision loss that occurs with AMD is called central vision loss. People experiencing this type of vision loss will have a blurred area at the center of their vision that can make it difficult to read, drive, and perform tasks that require attention to visual details. While AMD does not cause complete blindness, symptoms worsen with time, and vision can become severely impaired, resulting in legal blindness.

To understand AMD, it helps to understand two specific parts of the eye—the retina and the macula.

Retina and macula
The retina is a thin layer of tissues located at the back of the eye, near the optic nerve. Light that is focused by the lens of the eye is directed at the retina, which converts light into neural signals, which are then sent to the brain. The macula is the most sensitive part of the retina, located at its center, made up of millions of light-sensitive cells. As a person ages, the retina and macula can become damaged and deteriorate. The exact reason for this is unclear, but AMD is associated with the formation of drusen, fatty deposits of cell waste that accumulate in and around the retina.

In the early and intermediate stages of AMD, this deterioration may not cause vision loss or noticeable symptoms. When vision loss begins to occur, it is considered late AMD. There are two types of late AMD. One is called dry AMD, and the other called wet AMD.

Dry AMD versus wet AMD
Dry age-related macular degeneration is the more common of the two types, accounting for roughly 80 to 90 percent of cases. It typically affects both eyes at the same time.

Wet age-related macular degeneration is the less common of the two types, occurring in 10 to 20 percent of cases. Nearly all cases of wet AMD begin as dry AMD. With wet AMD, abnormal blood vessels form beneath the retina. These blood vessels can leak blood and fluid into the eye, which damages the cells of the retina. They can also scar, causing permanent vision loss. The progression of vision loss is often much quicker with wet AMD, occurring over days or weeks. Wet AMD can affect both eyes, but it is more common to have wet AMD in just one eye.

Taking care of your eyes
Regular eye exams can identify AMD early, and it is important to see an eye doctor regularly. If you or a loved one has symptoms of AMD, it is crucial to work with an eye doctor who can assess what is causing the vision loss, explain what treatment options are available, and refer you to specialists that can help you learn ways of coping with vision loss.

Medically reviewed in September 2019.

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