Geographic atrophy, a late-stage form of age-related macular degeneration (AMD), can be challenging to navigate — whether you have recently been diagnosed or have been living with its effects, such as blind spots, for some time. Doctors and researchers are continually learning about what exactly causes this eye disease. Studies so far have indicated that a faulty immune system and genetics are among the causes to blame.
In this article, we’ll discuss what’s known about the main known causes and risk factors for geographic atrophy. For a deeper understanding of your individual risk factors and how they apply to you, it’s important to have an open discussion with your eye doctor.
Geographic atrophy is the most advanced form of dry age-related macular degeneration (AMD). The condition develops when there’s damage to the macula — the center of the retina. Your retina is the light-sensitive tissue located at the back of your eye. Macular damage from AMD typically leads to central vision loss. You may notice large blind spots or have trouble seeing in low light.
Dry AMD is age-related, which means that it tends to develop as you get older. This is because inflammation and other stressors damage your eyes over time. Specifically, the retinal pigment epithelium (RPE) in your retina becomes damaged. The RPE is made of pigmented cells that protect the retina and provide nutrients.
Over time, inflammation leads to the formation of drusen. These are deposits of fat, protein, and debris that create yellow clumps beneath the retina. People with certain types of drusen are more likely to develop geographic atrophy.
Your immune system works around the clock to protect you from invading viruses, bacteria, and other harmful substances. Sometimes, certain parts of the immune system become too active and begin harming your healthy cells and tissues. Researchers believe the complement system plays a key part in geographic atrophy.
The complement system is made of around 50 different proteins that work together to activate inflammation and destroy foreign invaders. Most of the time, your complement system recognizes only outsiders like bacteria and viruses. However, studies show that this system also attacks the macula.
Uncontrolled inflammation from the complement system likely leads to geographic atrophy. We also know that immune cells in the eyes of people with dry AMD make high levels of substances related to inflammation.
Long-term inflammation kills RPE cells. This creates areas of atrophy (cell death). Your eye doctor can see these lesions when they take a close look at your retina during an eye exam. They can look like continents on a map — which is where the term “geographic atrophy” comes from.
Like other types of AMD, there are many associated risk factors that can make it more likely someone will develop geographic atrophy. However, some people develop the condition without having any known risk factors.
Having a family history of AMD and geographic atrophy puts you at risk of developing the condition yourself. This is because genes are passed down through family members. Other genetic conditions affecting your eyes can also play a role in your geographic atrophy risk.
Your genetics play a role in your risk of diseases. Studies show that people with geographic atrophy can have mutations (variations) in genes in complement proteins. These variations may be one of the underlying causes of geographic atrophy.
Smoking is another major cause of geographic atrophy. Cigarette smoke contains thousands of toxic chemicals that damage the delicate tissues in the eyes. The smoke also contains tar that leads to the formation of drusen. Older studies show that, overall, people who previously smoked are three times as likely to develop geographic atrophy compared to people who have never smoked.
If you’re concerned about your risk of geographic atrophy, talk to your eye doctor. They can recommend healthy lifestyle changes and treatments proven to slow the progress of geographic atrophy.
The organization Prevent Blindness recommends getting regular eye exams to monitor your eye health over time. You can also check your vision at home using an Amsler grid — a picture containing grids of straight lines. If you notice the lines are wavy or broken, it could mean you have geographic atrophy.
Developing healthy habits can also keep your eyes healthy. It’s important to quit smoking to lower your risk of geographic atrophy. Eating a diet high in antioxidants is also key. Try adding more fruits and leafy green vegetables to your meals.
Your eye doctor may recommend taking a supplement formula known as AREDS2. Studies show this mix of vitamins and nutrients may not prevent progression to geographic atrophy. However, AREDS2 reduces the risk of developing wet AMD. This type of AMD occurs when abnormal blood vessels damage the retina.
Unfortunately, there’s no way to reverse vision loss from geographic atrophy once the damage is done. Your eye doctor can prescribe treatments to help slow its progression. The U.S. Food and Drug Administration (FDA) approved two geographic atrophy treatments in 2023:
Both treatments work by blocking complement proteins to reduce inflammation. Together with lifestyle changes, the right treatment plan can help improve your quality of life with geographic atrophy.
Researchers are also looking for new ways to treat eye diseases, including geographic atrophy. The American Academy of Ophthalmology notes there are several clinical trials underway to treat this disease.
On myAMDteam, the social network for people with age-related macular degeneration and their loved ones, members who understand life with age-related macular degeneration come together to share support, advice, and stories from their daily lives.
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