Traditionally, 2 types of age-related macular degeneration have been differentiated: the "dry" and "wet" form.
The "dry form " may progress for many years with few or no symptoms. A percentage of these patients but will transfer to the "wet form" of the disease with rapid deterioration and severe symptoms.
The early stages of age-related macular are characterized by the appearance of yellowish deposits of proteins and lipids ("drusen") in the macula,with the patient usually being asymptomatic. Then these deposits increase in number and expand, causing the first symptoms and the central vision. In the final stages of "dry" age-related deterioration, the retina presents clear demarcated areas of atrophy, in relation to "atrophic age-related degeneration", which is often referred to as "geographic atrophy" due to the macula taking the shape of a geographical map.
The appearance of choroidal neovascularization (ie, pathological, particularly fragile vessels that invade the retina externally from the choroid) marks the transition to the "wet" age-related macular degeneration, which occurs in approximately 15% of patients with the dry form. The rupture of these new vessels leads to the exit of the fluid (which causes swelling in the macula) and blood, with a direct impact on vision.
If the disease is left without proper treatment, it will eventually lead to the creation of fibrous tissue (scar) and complete loss of central vision.