QUESTION: I have AMD. What’s my chance of having vision loss?
This information is ONLY for AMD, it doesn’t apply to any other form of macular degeneration.
I don’t want to give people false hope, but I want to make sure that the risk for those with early or intermediate AMD is accurate. The large number of posts about wet AMD in our Facebook group does NOT mean that everyone will progress to it eventually.
Also, just because it’s called Advanced Dry AMD (which is Geographic Atrophy) does NOT mean that everyone will go from early to intermediate to advanced dry AMD.
Advanced dry AMD/Geographic Atrophy or Wet AMD are NOT inevitable!
What does vision loss mean?
Vision loss means that photoreceptors are dead.
There are cells that ‘take care of’ photoreceptors that are called called RPEs (Retinal Pigment Epithelium). One job of the RPEs is to remove waste material called drusen from the photoreceptors. When this drusen piles up under the RPEs, it blocks the photoreceptors from getting the ‘food’ they need to keep working. When the RPEs fail, vision impairment can occur.
Photoreceptor death and vision loss can occur in the advanced stages of AMD: wet and geographic atrophy/advanced dry.
Photoreceptor death causes vision loss in the other forms of macular degeneration, but the causes are different from those of AMD.
What’s my risk of vision loss if I have early or intermediate AMD?
Early AMD is diagnosed by the presence of medium-sized drusen which are about the width of an average human hair. People with early AMD typically do not have vision loss. For those with early dry AMD, there’s a 10% risk of progressing to wet AMD in 10 years. Not sure of % risk of progressing to advanced dry AMD/geographic atrophy (GA), but it is similar.
People with intermediate AMD typically have large drusen, pigment changes in the retina, or both. Intermediate AMD may cause some vision loss, but most people will not experience any symptoms. Many people will have vision impairment. For intermediate AMD, the risk is a little higher than that of early AMD: 14-15% to wet AMD. Not sure of % risk of progressing to advanced dry AMD/geographic atrophy (GA) but it is similar.
What’s my risk of vision loss if I have advanced dry or wet AMD?
Geographic atrophy is vision loss caused by dead photoreceptors that when looked at by an eye specialist resembles a pattern of islands of damage. Vision loss results in one or more blind spots.
Wet AMD is also called neovascular AMD (“Neovascular” literally means “new vessels.”). 90% of all vision loss is from wet AMD – most of the time it occurs when it is not detected early and not treated with anti-VEGF injections. Abnormal blood vessels grow underneath the retina. These vessels can leak fluid and blood, which may lead to swelling and damage of the macula. The damage may be rapid and severe, unlike the more gradual course of geographic atrophy. It is possible to have both geographic atrophy and neovascular AMD in the same eye, and either condition can appear first.
References
Treatments for dry age-related macular degeneration and Stargardt disease: a systematic review.
What is AMD? from the National Institute of Health (NIH) National Eye Institute (NEI)
Excellent source of information including videos, illustrations & brochures: The Angiogenesis Foundation