Age-related macular degeneration (AMD) is a leading cause of vision loss in older adults, affecting the macula—the part of the eye responsible for sharp, central vision. Among the two types of AMD, dry and wet, dry AMD is the more common form and often progresses gradually. A subset of dry AMD, called geographic atrophy (GA), is a more advanced and severe stage of the disease. Understanding the differences between AMD and GA can help patients better navigate their eye health journey and explore treatment options.

What is Age-Related Macular Degeneration (AMD)?

AMD is a progressive eye condition that affects individuals typically over the age of 50. The deterioration of the macula characterizes it, the central part of the retina that provides clear, detailed vision needed for activities like reading, driving, and recognizing faces.

Types of AMD:
 

• Dry AMD (non-exudative): The most common form, accounting for about 85-90% of AMD cases, results from the thinning of the macula and the accumulation of drusen (yellow deposits) beneath the retina.
   

• Wet AMD (exudative): A less common but more severe form, caused by abnormal blood vessel growth under the retina, leading to fluid or blood leakage and rapid vision loss.

What is Geographic Atrophy (GA)?

Geographic atrophy is an advanced form of dry AMD and a significant cause of severe vision loss. GA occurs when the cells in the macula die off in distinct patches, creating "geographic" areas of atrophy where vision is completely lost. While it typically develops over time, GA can lead to significant central vision impairment, making everyday activities challenging.

Key Differences Between AMD and Geographic Atrophy

AMD encompasses both dry and wet forms, with dry AMD typically progressing slowly over time and wet AMD leading to more rapid vision loss due to abnormal blood vessel growth. Geographic atrophy (GA), a subset of advanced dry AMD, progresses more gradually but results in severe vision loss due to the death of retinal cells in specific areas of the macula.

While AMD often begins with mild symptoms like blurry vision and difficulty seeing in dim light, GA presents with more pronounced issues, including blind spots in the central vision and difficulty recognizing faces. Over time, GA significantly impacts daily activities that rely on sharp central vision.

Dry AMD is marked by the accumulation of drusen (yellow deposits) and thinning of the macula. In contrast, GA involves the complete degeneration of retinal cells in distinct "geographic" patches, leading to permanent vision loss in affected areas.

For AMD, treatments range from lifestyle changes and AREDS2 supplements for dry AMD to anti-VEGF injections for wet AMD. Unfortunately, there is no cure for GA, but emerging treatments aim to slow its progression and preserve remaining vision.

Diagnosing AMD and GA

Routine eye exams are crucial for detecting these conditions early, even before noticeable symptoms develop. Early detection can slow disease progression and preserve vision through timely intervention and management strategies. If you’re over 50 or have a family history of AMD, regular comprehensive eye exams should be a priority.

Diagnosing AMD and geographic atrophy typically involves several advanced tools and tests:
 

• Dilated Eye Exam: This allows your eye doctor to check for drusen (yellow deposits) or other abnormalities in the retina, which are early indicators of AMD.
   

• Optical Coherence Tomography (OCT): A non-invasive imaging test that produces detailed cross-sectional images of the retina, helping to identify thinning or cell loss in the macula.
   

• Fundus Photography: High-resolution images of the back of the eye are captured for documentation and to monitor changes over time.
   

• Amsler Grid Test: A simple test used to identify vision distortions, such as wavy or missing lines, that could signal macular damage.

Schedule Your Next Eye Exam Today

Detecting AMD or GA early can make a significant difference in preserving your vision and maintaining your quality of life. At Clarity Vision, our experienced team uses advanced diagnostic tools to identify and monitor macular conditions. 

If you have concerns about AMD or geographic atrophy, schedule an eye exam with Clarity Vision for expert care. Visit our office in Holly Springs, North Carolina, or call (919) 646-2900 to book an appointment today.