What is geographic atrophy?
Geographic atrophy (GA) is a chronic progressive degeneration of the macula, which occurs as part of late-stage age-related macular degeneration (AMD). This is a subset of the “dry” form of macular degeneration. Macular degeneration is an eye condition that affects the macula; the small central part of your retina responsible for your central vision. If you have geographic atrophy, you’ll have blind spots, also called scotomas, in your central vision, and you may lose some sharpness of vision. An estimated 1 million people in the United States have geographic atrophy.
What are the symptoms of geographic atrophy?
Geographic atrophy is a late stage form of macular degeneration. You might not notice symptoms in early stages, or while the condition is in one eye only. When they do occur, geographic atrophy symptoms include:
- Loss of visual acuity (sharpness of vision)
- Difficulty reading, driving, or any other activity that relies on central vision
- A dark or blind spot, in your central vision
- Difficulty seeing in dim light
- Colors becoming muted or less vibrant
What causes geographic atrophy?
Geographic atrophy is the last stage of dry age-related macular degeneration. Researchers and physicians don’t know the actual cause of geographic atrophy, but they think your immune system plays a role. Genetic and environmental factors also might play a part.
What are the risk factors for geographic atrophy?
There are risk factors for geographic atrophy, which make it more likely that a person will develop the condition. Risk factors for geographic atrophy include:
- Being age 60 or older
- Being caucasian
- Having eyes that are light in color
- Family history of macular degeneration or other retinal conditions
- Having a history of an unhealthy diet
- Having a history of spending a lot of time in the sun
- Chronic health conditions such as obesity, high blood pressure, high cholesterol, diabetes, or heart disease
How is geographic atrophy diagnosed?
An ophthalmologist or optometrist will diagnose geographic atrophy through a combination of a comprehensive dilated eye exam and diagnostic imaging tests. They’ll also check your visual acuity and ask you about your symptoms, medical history and family medical history.
What tests will be done to diagnose geographic atrophy?
To diagnose geographic atrophy, your eye provider may order diagnostic imaging tests called Fundus Autofluorescence (FAF) or Optical Coherence Tomography (OCT).
Fundus autofluorescence imaging is used to record fluorescence that may occur naturally in ocular structures or as a byproduct of a disease process. This technique allows the topographic mapping of lipofuscin distribution in the pigmented layer of the retina. In areas with geographic atrophy, the Fundus Autofluorescence (FAF) will appear dark due to loss (i.e. death) of retinal pigment epithelial cells that contain lipofuscin.
Optical coherence tomography (OCT) imaging uses reflected light to create a cross-sectional view of the retina, which can detect thinning and deterioration of retinal cells.
How is geographic atrophy treated?
Up until recently, there were no treatments for GA secondary to dry AMD. The U.S. Food and Drug Administration (FDA) recently approved the first medication to treat geographic atrophy. Syfovre™ (Pegcetacoplan), is an intraocular injection that may slow the progression of the disease. Other ways of managing geographic atrophy include:
- Low vision rehabilitation: This features a variety of services that include prescription eyewear, obtaining visual aids like magnifying glasses and learning to manage activities of daily living.
- AREDS2 vitamin supplements: The Age-Related Eye Disease Study tested these antioxidant-containing supplements. Some eye physicians use these to help manage dry age-related macular disease.
- Implantable miniature telescope (IMT): Your retinal surgeon replaces your lens with an IMT. The device magnifies things in your central vision and focuses them on other areas of your retina that are still working.
How can I lower my risk of developing geographic atrophy?
Unfortunately, geographic atrophy cannot be prevented. However, you may be able to lower your risk of developing geographic atrophy by addressing modifiable risk factors. Modifiable risk factors are things you can change, unlike age or ethnicity.
You may lower your risk by:
- Not smoking
- Managing chronic conditions like diabetes, high blood pressure, obesity and high cholesterol
- Wearing protective eyewear, such as yellow-tinted sunglasses to protect the macula in each of your eyes or safety glasses when you’re working
- Eating a healthy diet that includes dark leafy greens and fatty fish and limiting packaged foods and artificial fats
- Getting regular physical activity
What can I expect if I have geographic atrophy?
The disease progresses differently for each person. Generally speaking, GA can cause the development of blind spots and decreased sharpness in vision over time. The outlook may be getting better, however, as new treatment options are on the horizon for treating geographic atrophy. With the help of visual aides, vitamin supplementation, and the advent of new GA treatment options, many people live full lives even with decreased vision due to GA.