Macular Degeneration – Causes, Symptoms and Treatments of Wet and Dry AMD Age-Related Macular Degeneration (AMD) usually affects older adults and results in a loss of vision in the center of the visual field (the macula) because of damage to the retina. It occurs in “dry” and “wet” forms. A major cause of blindness and visual impairment in older adults, AMD can make it difficult or impossible to read or recognize faces, although enough peripheral vision remains to allow other activities of daily life.
01 Eye Works-The Macula
The macula is a small specialized area of the retina responsible for straight-ahead reading and driving vision. The retina reacts to light through a chemical process which then sends nerve impulses directly to the brain where the “picture” is processed.
02 Dry AMD – Age-Related Macular Degeneration
The “dry” form of macular degeneration is characterized by the presence of yellow deposits, called drusen, in the macula. A few small drusen may not cause changes in vision; however, as they grow in size and increase in number, they may lead to a dimming or distortion of vision that people find most noticeable when they read.
03 Amsler Grid
The Amsler grid is a tool that eye doctors use to detect vision problems resulting from damage to the macula (the central part of the retina) or the optic nerve.
04 Wet AMD – Age-Related Macular Degeneration
The “wet” form of macular degeneration is characterized by the growth of abnormal blood vessels from the choroid underneath the macula. This is called choroidal neovascularization.
05 Standard Laser Therapy
Retinal laser photocoagulation is a type of laser surgery that uses an intense beam of light to burn small areas of the retina and the abnormal blood vessels beneath the macula. The burns form scar tissue that seals the blood vessels, keeping them from leaking under the macula.
06 PDT – Photodynamic Therapy for Age-Related Macular Degeneration
Photodynamic therapy (PDT) is a treatment for wet age-related macular degeneration (wet AMD). It is not used to treat dry AMD.
In photodynamic therapy, a light-sensitive medicine called verteporfin (Visudyne) is injected into the bloodstream. The medicine collects in the abnormal blood vessels under the macula. Laser light is then shone into the eye, which activates the medicine and causes it to create blood clots that block the abnormal blood vessels.
Animation credit: American Academy of Ophthalmology