What Is Geographic Atrophy?
Geographic atrophy (GA) is a chronic eye condition in which the cells in the retina slowly break down and die. This results in poor retinal function and affects a person’s vision.1
GA mainly occurs in people over the age of 60 who have age-related macular degeneration (AMD). GA is also known as dry age-related macular degeneration or dry AMD. Dry AMD accounts for roughly 85 to 90 percent of AMD cases worldwide. According to a 2014 study, dry AMD is more common among those with European ancestry.2,3 Of those who completed Macular Degeneration In America survey, 5% of the maculardegeneration.net community in 2020 was diagnosed with geographic atrophy.
GA can affect just 1 eye or both eyes. However, if a person has GA in 1 eye, they are more likely to develop it in the other. Because it is more common as a person ages, the longer people live, the more likely they will develop GA.1
Geographic atrophy symptoms result in blind spots in a person’s central field of vision, meaning directly in front of them. For example, a person might be reading a book and notice certain letters in a word are missing. Or, when looking directly at an object, part of the object is blurry.1
Once GA occurs, it slowly spreads to other regions of the retina and gets worse over time. While GA affects a person’s central field of vision, it usually does not impact a person’s peripheral vision.1
The rate of progression is different for each person. Some people with GA might experience partial vision loss, while others may develop total vision loss over time.4,5
How is it diagnosed?
An ophthalmologist diagnoses GA by performing a dilated eye exam. During this kind of eye exam, eye drops are used to dilate the eye. This allows the ophthalmologist to see the back of the eye, including the entire retina.4
A telltale sign of GA is if a large amount of drusen, or yellow deposits, is found beneath the retina. To a person performing the eye exam, it will look as if part of the retina is missing its dark melanin pigment.1
Retinal imaging is another way to detect GA. Different imaging tests can be used, including:4
- Retinal color photographs, which captures 30- to 50-degree views of the retina and optic nerve
- Optical coherence tomography (OCT), an imaging method that takes cross-section pictures of the back of the eye
- Autofluorescence photographs, which use a fluorescent blue light to view the layers of the retina.
Are there risk factors?
Age is the main risk factor for developing dry AMD. Smoking is the second most common risk factor. Genetics and family history also play a part.5
Studies have shown that GA is also more common in white people than in people of color. Other risk factors like gender and chronic light exposure are being studied.5
What are the treatment options?
While there is no cure for GA, there are ways to help manage this type of gradual vision loss. For example, increased lighting, magnification, and low vision devices that can help with reading are some eye care therapies that can offer support.1
Lifestyle habits may also help to slow down the progression of GA. Along with stopping smoking, doctors recommend:5
- Vitamin supplements
- A nutritious diet rich in antioxidants
- Regular exercise
- Reducing alcohol
- Lowering cholesterol and blood pressure
Current research for GA
Several clinical trials are in progress to study GA and find a cure. Some, like stem cell treatments to regenerate damaged cells, are showing positive results. Other gene therapies are being explored and provide hope for people living with GA.4,5
If you are interested in learning more about clinical trials for GA, talk to your doctor or search for GA trials on the ClinicalTrials.gov website.
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