Geographic Atrophy and Wet AMD are two significant forms of macular degeneration impacting vision. Understanding these conditions is crucial for effective management and treatment.
Geographic atrophy (GA) and wet age-related macular degeneration (wet AMD) affect the central portion of the retina and can have profound impacts on daily living. These conditions represent different facets of advanced macular degeneration, each with unique characteristics and challenges. Our eye doctors are here to help you understand these conditions, their risk factors, and what they mean for your vision.
Understanding the difference between geographic atrophy and wet AMD begins with a clear picture of the eye’s anatomy. The macula, a small but vital part of the retina, is responsible for our sharp central vision, which helps us read, drive, and recognize faces. In both geographic atrophy and wet AMD, damage to this critical area leads to visual impairment, though they do so in different ways.
Geographic atrophy is an advanced form of dry age-related macular degeneration. It is marked by a gradual, yet irreversible, loss of retinal cells, affecting the retinal pigment epithelium (RPE), overlying photoreceptors, and the choriocapillaris underneath. This deterioration typically begins in the area surrounding the central fovea and eventually spreads to involve it, resulting in notable blind spots called central scotomas and a loss of visual acuity.
Clinically, geographic atrophy is observed as sharply demarcated areas on clinical examinations, where the normal color and thickness of the retina have been lost. As these atrophic areas expand, patients may notice a progressive decline in their ability to read, see faces clearly, or perform tasks that require fine details. Even if visual acuity remains nearly normal in the earlier stage because the fovea may be spared for some time, issues like reduced contrast sensitivity and difficulties with color discrimination are common.
Wet AMD, in contrast, is characterized by the rapid growth of abnormal blood vessels beneath the retina. These new vessels are fragile and can leak fluid or bleed, leading to swift and significant damage to the macula. Although wet AMD is less common than its dry counterpart, it accounts for the majority of legal blindness related to macular degeneration.
The hallmark of wet AMD is the presence of choroidal neovascularization. On clinical examination and imaging studies, our eye doctors can observe these abnormal vessels and any resulting fluid accumulation. The onset of wet AMD is often sudden, which makes prompt diagnosis and treatment critical to preserve vision.
Several risk factors are associated with the development of both geographic atrophy and wet AMD. Being informed about these factors can empower you to have meaningful discussions with our eye doctors regarding your eye health and lifestyle adjustments that may help reduce risks.
For wet AMD, additional factors include the presence of lipid disorders like hypercholesterolemia, previous visual acuity levels, and pre-existing retinal changes. The intensity of these risk factors may vary between individuals, and regular checkups are important to monitor any progression of the disease.
Schedule your appointment today to discuss your vision health and find a top optometrist or ophthalmologist near you.
The natural history of macular degeneration starts with early changes which may include the development of drusen—yellow deposits located between the retinal pigment epithelium and Bruch’s membrane. Over time, these deposits may lead to further complications. While both conditions share these early signs, their progression diverges in the later stages.
In geographic atrophy, the mechanism involves chronic degeneration in which localized areas of the retina lose the support of the RPE. This results in sharply demarcated areas where the retinal tissue has atrophied, revealing the underlying choroidal vessels. In many instances, the condition is bilateral and its expansion gradually diminishes central vision.
Wet AMD, on the other hand, is driven by abnormal blood vessel growth. The process of neovascularization means that fragile vessels form and begin to leak. This leakage causes rapid retinal damage, often leading to quicker and more severe vision loss if not treated in time.
Although each condition affects the macula, the signs and symptoms can vary, often influencing how and when patients seek treatment. Here’s a closer look at what you might notice if you are developing geographic atrophy or wet AMD:
These signs do not always occur simultaneously, and some patients might notice only subtle changes initially. This gradual decline in functional vision highlights the importance of regular eye examinations.
The sudden onset of these symptoms in wet AMD makes early detection critical. If you experience any such symptoms, it’s essential to consult with our eye doctors as soon as possible.
Schedule your appointment today to discuss your vision health and find a top optometrist or ophthalmologist near you.
Explore the differences between Geographic Atrophy and Wet AMD, their symptoms and treatment options, to better manage your vision health.
