Geographic Atrophy Overview
Geographic atrophy (GA) is a severe, progressive, and chronic condition that is a major cause of central vision loss. GA is an advanced form of age-related macular degeneration (AMD). It affects over a million people in the USA and is most common in people 65 years and older who have been diagnosed with AMD.
GA damages the macula, the central part of the eye used to see colors and details.
What Research Says About Geographic Atrophy
There are many causes of geographic atrophy, making the disease complex to study. Research suggests that a combination of genetics, the immune system, and environmental factors may be involved.
One area of active research focuses on the role of vitamin A. This is because vitamin A is the “light switch” of the eye and is essential for vision. As eyes age, they may not easily transport molecules, including vitamin A, in and out of the eye. This results in vitamin A forming clumps (called “vitamin A dimers”), which are toxic to the eye and may be responsible for the development and progression of vision loss in geographic atrophy and AMD.
Researchers believe that many risk factors contribute to the development or progression of geographic atrophy. Risk factors thought to be important include increasing age, having AMD (wet or dry), smoking, white ethnicity and genetics.
An eye doctor (ophthalmologist or optometrist) looks into the back of a patient’s eye with a microscope and takes a few photographs to confirm the diagnosis. These images commonly include color fundus photographs, fundus autofluorescence and optical coherence tomography.
This image shows what doctors might see in the eye of a patient with geographic atrophy
Symptoms of Geographic Atrophy
Symptoms or disease progression vary by individual. Although the most frequent symptom is reduced visual acuity, some people retain good vision for years. Visual acuity is the ability of seeing sharp details in the center of vision. Common symptoms of geographic atrophy include:
- Blurry central vision
- Blind spots in vision
- Distorted vision
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