Geographic Atrophy

Geographic Atrophy Care in Chattanooga, Knoxville, and the Tri-Cities Region

Geographic atrophy is a retinal condition occurring in the final stages of dry age-related macular degeneration (AMD). An incurable, degenerative disorder, it involves the development of lesions impacting the retinal pigment epithelium (RPE), a vital tissue layer responsible for the retina’s nourishment and metabolic processes. The retina specialists at Southeastern Retina Associates are experienced in diagnosing and treating this global health threat, employing state-of-the-art treatments, to delay or stop its progression and preserve your existing vision.

What is Geographic Atrophy?

With dry AMD, the macula gradually deteriorates. With geographic atrophy, this tissue deterioration leads to the formation of lesions – small areas of atrophy, or cell death. Initially, this occurs along the edge of the outer retina, but as the lesions expand, they begin to overlap, growing into and impacting the center of the macula, known as the fovea.

Containing the highest concentration of cone photoreceptor cells in the macula, the fovea is responsible for central vision, allowing you to perform various activities, like driving, reading, or anything requiring visual acuity. As such, the cell death that happens with geographic atrophy can have a dramatic impact on your quality of life. It’s not clear as to what causes geographic atrophy, although researchers suspect that the immune system, specifically a part called the complement cascade, is involved. Genetic and environmental factors may also be involved.

Symptoms of Geographic Atrophy

Common symptoms of geographic atrophy include:

-Gradual Central Vision Loss: Individuals may experience a slow but progressive loss of central vision over time.

• Blurred Vision: Vision may become increasingly blurred, affecting the ability to see fine details.
• Difficulty Reading or Recognizing Faces: Geographic atrophy can impact tasks that require clear central vision, such as reading or recognizing faces.
• Distorted Vision: Some individuals may perceive straight lines as wavy or distorted.
• Decreased Color Vision: A reduction in the ability to perceive and distinguish colors may occur.
• Visual Disturbances in Low Light: Vision problems may be more pronounced in low-light conditions.

Geographic Atrophy Risk Factors

The main risk factor of geographic atrophy is age, as it primarily affects people over the age of 50. Other factors can also have an impact, including:

• A family history of AMD and geographic atrophy
• Having light-colored irises (the colored eye part surrounding the pupil that regulates incoming light levels)
• Obesity
• Underlying conditions, such as diabetes, hypertension, and high cholesterol
• Smoking (all types)
• A low-nutrient diet
• Having previously had cataract surgery

Another important risk factor is having poor visual acuity. It’s been shown that patients with visual acuity at or worse than 20/200 had almost a 3-fold greater risk of developing GA compared to those with a baseline of 20/25-20/40.

Diagnosing Geographic Atrophy

If living with AMD, regular retinal exams are essential, especially if you have other risk factors for geographic atrophy. This exam typically consists of the following diagnostic testing measures:

• Visual acuity test, to measure how well you can see at various distances
• Dilated eye exam, in which the pupils are widened using special drops to allow a more detailed examination of the retina
• Fundus autoflfuorescence
• Optical coherence tomography (OCT)
• Fluorescein angiography

These regular visits provide an effective method for dry AMD and geographic atrophy patients to regularly monitor their vision. It’s also strongly recommended that you monitor your vision at home with the daily use of an Amsler grid.

Treatment for Geographic Atrophy

While geographic atrophy was previously untreatable, this changed in 2023 with the U.S. Food and Drug Administration (FDA) approving the drug Syfovre (pegcetacoplan injection). The first and only treatment, Syfovre has been found to effectively delay its lesion formation, while also allowing for flexible dosing. It’s injected directly into the vitreous of the eye. Syfovre works by inhibiting a unique protein in a part of the immune system (the complement cascade).

Lifestyle Modifications to Manage and Prevent Geographic Atrophy

As with AMD, adopting certain lifestyle changes and other preventive measures may help to slow its progression, allowing you to keep your existing central vision. Those methods that can be modified include:

Ensuring the proper management of any underlying conditions, like obesity, diabetes, and high blood pressure and cholesterol
Getting consistent daily physical activity
Avoiding smoking
Protecting your eyes from harmful UV ray exposure

If living with this condition, you may find it helpful to use visual rehabilitation services and assistive devices, such as prescription eyewear or magnifying glasses.

Geographic Atrophy FAQ

• What is the prevalence of geographic trophy?

  Geographic atrophy affects about 1 million people in the United States, and an estimated 8 million worldwide. A leading cause of legal blindness, it comprises roughly 20% of all cases related to AMD. Research shows that 30% of dry AMD patients can expect to develop geographic atrophy. As for wet AMD, up to 37% may develop geographic atrophy within 2 years, with risks growing over time. By 7.3 years, 98% of wet AMD patients develop geographic atrophy.

• Can patients develop both wet AMD and geographic atrophy?

  While both are advanced forms of AMD, they are different disorders. Geographic atrophy may develop at the same time as wet AMD. However, it can also occur once wet AMD has formed, even after anti-VEGF injections have been administered as treatment. These disorders can also coexist in the same eye.

• What is the general prognosis for geographic atrophy?

  As there has previously been no treatment for geographic atrophy, and it can progress differently among patients, this condition’s outlook has not been positive. However, the FDA approval of Syfovre has now dramatically improved its prognosis. Even if vision loss does occur, geographic atrophy typically doesn’t affect life expectancy, with many people living full lives.