Dry AMD: The More Common Form
Dry AMD, also known as atrophic AMD, accounts for about 80 to 90 percent of all AMD cases, making it by far the more common form of the disease. The term 'dry' refers to the fact that no fluid leaks under the retina in this form - in contrast to wet AMD, where this is the case.
In dry AMD, there is a slow, progressive breakdown of cells in the macula. This process typically begins with the formation of drusen - small yellowish deposits that accumulate between the retinal pigment epithelium and the underlying Bruch'''s membrane. Drusen are visible during an ophthalmological examination and are considered an early sign of AMD.
Wet AMD: Rarer, but More Aggressive
Wet AMD, also known as exudative or neovascular AMD, accounts for about 10 to 20 percent of all AMD cases. Although it is rarer, it is responsible for a large proportion of severe visual impairments caused by AMD, as it progresses more quickly and can lead to rapid vision loss if left untreated.
The characteristic feature of wet AMD is the growth of abnormal blood vessels under the retina. These vessels, which grow from the choroid towards the retina, are unstable and leaky. They can secrete fluid and blood, leading to swelling and detachment of the retina.
Overview of the Key Differences
| Feature | Dry AMD | Wet AMD |
|---|---|---|
| Frequency | 80-90% of AMD cases | 10-20% of AMD cases |
| Progression | Slow, over years to decades | Fast, weeks to months |
| Main Feature | Drusen, geographic atrophy | Abnormal vessels, fluid, bleeding |
| Typical Symptoms | Gradual vision loss, difficulty reading | Sudden distortions, dark spot |
| Treatment | AREDS2 supplements, lifestyle, PBM | Anti-VEGF injections |
| Prognosis | Variable, often stable for years | Usually stabilizable with treatment |
Frequency
Progression
Main Feature
Typical Symptoms
Treatment
Prognosis
The Connection Between Both Forms
An important aspect that those affected should know: Dry AMD can transition to the wet form. This happens in about 10 to 15 percent of patients with dry AMD. It is therefore crucial for patients with dry AMD to remain vigilant and attend regular check-ups.
The Amsler grid test is a simple tool for detecting changes early. If straight lines suddenly appear wavy or distorted, this can be an indication of the transition to wet AMD. In this case, you should see an ophthalmologist immediately, as prompt treatment is crucial to preserve vision.
Important to Know
In case of sudden changes in vision, especially with new distortions or a dark spot in the field of view, you should consult an ophthalmologist immediately. These symptoms may indicate a transition to wet AMD, which requires immediate treatment.
Different Treatment Approaches
The treatment options differ fundamentally between the two forms of AMD. For wet AMD, effective medications have been available since about 2006: the so-called anti-VEGF drugs. VEGF (Vascular Endothelial Growth Factor) is a growth factor that stimulates the formation of new blood vessels. The drugs block this factor and can thus inhibit abnormal vessel growth.
For a long time, there were no approved treatments for dry AMD. The AREDS2 study has shown that certain dietary supplements can slow the progression in patients with intermediate to advanced AMD. Learn more about all treatment options for dry AMD. Newer approaches such as Photobiomodulation (PBM) are currently being intensively researched and are showing promising results.