The Difference Between Wet and Dry Age-Related Macular Degeneration
There are two types of AMD: dry (atrophic) and wet (neovascular or exudative). Most AMD starts as the dry type and in 10-20% of individuals, it progresses to the wet type. Age-related macular degeneration is always bilateral (i.e., occurs in both eyes), but does not necessarily progress at the same pace in both eyes. It is therefore possible to experience the wet type in one eye and the dry type in the other.
Dry Macular Degeneration
The dry (atrophic) type affects approximately 80-90% of individuals with AMD. Its cause is unknown, it tends to progress more slowly than the wet type, and there is not—as of yet—an approved treatment or cure. In dry age-related macular degeneration, small white or yellowish deposits, called drusen, form on the retina, beneath the macula, causing it to deteriorate or degenerate over time.
Wet Macular Degeneration
The wet/neovascular type affects approximately 10-15% of individuals with age-related macular degeneration, but accounts for approximately 90% of all cases of severe vision loss from the disease.
In wet age-related macular degeneration, abnormal blood vessels under the retina begin to grow toward the macula. Because these new blood vessels are abnormal, they tend to break, bleed, and leak fluid, damaging the macula and causing it to lift up and pull away from its base. This can result in a rapid and severe loss of central vision.
Although its cause is unknown, several new treatments are now available for wet age-related macular degeneration.
You can read more about both types of macular degeneration at Macular Degeneration International, Macular Degeneration Partnership, and Macular Degeneration Support, where you can also view a retinal photograph of dry AMD and drusen and a retinal photograph of wet AMD (also called exudative).