What is macular degeneration?
Age-related macular degeneration, often called AMD or ARMD, is the leading cause of vision loss and blindness among Americans who are age 65 and older. Because people in this group are an increasingly larger percentage of the general population, vision loss from macular degeneration is a growing problem.
AMD is degeneration of the macula, which is the part of the retina responsible for the sharp, central vision needed to read or drive. Because the macula primarily is affected in AMD, central vision loss may occur.
Wet and Dry Forms of Macular Degeneration
Macular degeneration is diagnosed as either dry (non-neovascular) or wet (neovascular). Neovascular refers to growth of new blood vessels in an area, such as the macula, where they are not supposed to be.
Macular degeneration mainly affects central vision, causing “blind spots” directly ahead.
The dry form is more common than the wet form, with about 85 to 90 percent of AMD patients diagnosed with dry AMD. The wet form of the disease usually leads to more serious vision loss.
Dry Macular Degeneration (non-neovascular). Dry AMD is an early stage of the disease and may result from the aging and thinning of macular tissues, depositing of pigment in the macula or a combination of the two processes.
Dry macular degeneration is diagnosed when yellowish spots known as drusenbegin to accumulate in and around the macula.
Gradual central vision loss may occur with dry macular degeneration but usually is not nearly as severe as wet AMD symptoms.
Wet Macular Degeneration (neovascular). In about 10 percent of cases, dry AMD progresses to the more advanced and damaging form of the eye disease. With wet macular degeneration, new blood vessels grow beneath the retina and leak blood and fluid. This leakage causes permanent damage to light-sensitive retinal cells, which die off and create blind spots in central vision.
Age-Related Macular Degeneration Symptoms and Signs
Age-related macular degeneration usually produces a slow, painless loss of vision. In rare cases, however, vision loss can be sudden. Early signs of vision loss from AMD include shadowy areas in the central vision or unusually fuzzy or distorted vision.
An Amsler grid consists of straight lines, with a reference dot in the center. Someone with macular degeneration may see some of the lines as wavy or blurred, with some dark areas at the center.
A macular degeneration diagnosis is made through regular ophthalmic eye and special sophisticated exams which include:
• Fluorescein angiography,
• Indocyanine green (ICG) angiography
• Optical coherence tomography (OCT) uses special rays of light to scan your retina and produce an image of it. This can provide your ophthalmologist with detailed information about your macula such as if the macula is thickened or if is abnormal in any way, and whether any fluid has leaked into the retina
How Macular Degeneration Is Treated
For wet AMD, treatments aimed at stopping abnormal blood vessel growth include FDA-approved drugs called Lucentis, Eylea and Visudyne used with Photodynamic Therapy or PDT.