Age-related macular degeneration (AMD) is the most frequent cause of vision loss among people 50 years and older in developed countries. If only one eye is affected, patients may not even be aware that they have AMD. Other people may fail to report vision loss because they believe it to be an inevitable consequence of aging. Early diagnosis and treatment is very important to the outcome of macular degeneration. A significant delay can reduce the likelihood of any improvement in visual function. AMD can be classified as either dry or wet. Dry AMD is characterized by the build up of drusen, which are small yellow deposits underneath the retina. Dry AMD often does not cause severe vision loss unless the retina and underlying layers begin to atrophy and die. It is important to monitor patients with dry AMD because it may progress to wet AMD, which can be treated. The wet form accounts for approximately 90% of severe vision loss in patients with AMD. Wet AMD is characterized by the presence of choroidal neovascularization, which is a term that describes abnormal new blood growth underneath the retina. The main symptoms of wet AMD are deterioration in central vision, blind spots, and distorted vision. Definitive diagnosis and classification of choroidal neovascularization requires fluorescein angiography, ocular coherence tomography, and color fundus photography of the retina. The location of neovascular lesions is an important factor in determining the risk of vision loss. Eyes with subfoveal lesions (those that extend under the center of the retina) are at the greatest risk of vision loss.