Macular Degeneration
Macular degeneration also called age-related macular degeneration (ARMD or AMD), is an age-related condition in which the most sensitive part of the retina, the macula, begins to break down and lose its ability to create clear visual images. The macula is responsible for our central vision. The part of our sight we use to read, drive, and recognize faces.
ARMD is the leading cause of vision loss and blindness in Americans of ages 65 and older. It is estimated that more than 1.75 million U.S. residents currently have significant vision loss from ARMD, and the number is expected to grow to almost 3 million by 2020.
Forms of Macular Degeneration
There are two forms of macular degeneration, dry (non-neovascular) or wet (neovascular). The term neovascular refers to the growth of new blood vessels.
Dry AMD (non-neovascular)
Dry AMD is the most common form of the disease, making up about 85%-90% of all cases of AMD. It is characterized by blurred central vision or blind spots, as the macula begins to deteriorate. Dry AMD is an early stage of the disease and is less severe than the wet form.
Dry AMD occurs when the aging tissues of the macula begin to thin out and break down. Tiny pieces of white or yellowish protein called drusen begin to appear, which are thought to be deposits from the macular tissue as it deteriorates. The appearance of these drusen are often what leads to a diagnosis of AMD during an eye exam.
With dry AMD vision loss happens gradually, however, the dry form can progress to wet AMD rapidly. There is currently no cure for dry AMD, however there is research that shows that some people can benefit from supplemental vitamin therapy including antioxidants, lutein and zeaxanthin.
Wet AMD (neovascular)
Wet AMD is less common occurring in only about 10 percent of those with AMD. AMD is classified as Wet AMD when abnormal blood vessels begin to grow under the retina and leak fluid and blood into the macula, resulting in blind spots and a loss of central vision. Wet AMD can cause more damage to vision and permanent scarring if not treated quickly, so any sudden blur in vision should be assessed immediately, especially if one is aware that they have AMD. Usually vision loss happens faster and is more noticeable than in dry AMD so the quicker it is treated, the more vision you can preserve.
Symptoms & Risk Factors of Macular Degeneration
Macular Degeneration can cause low vision and debilitating vision loss, even blindness if not diagnosed and treated in the early stages. Because the disease often has no obvious symptoms early on, it is critical to have regular comprehensive eye exams, particularly if you are at risk.
Symptoms of AMD
Macular degeneration is a disease in which the macula slowly breaks down, resulting in a gradual progressive vision loss, at least in its’ early stages. Frequently there are no symptoms and the disease is only diagnosed when a doctor detects signs such as a thinning macula or the presence of drusen in a comprehensive eye examination. Early vision loss can include blurry, cloudy or distorted central vision or dark spots in your central field of view. With advanced stages, vision loss can be severe and sudden with larger blind spots and total loss of central vision.
Risk Factors for Macular Degeneration
Age is the most prominent risk factor for AMD, as the disease is most common in individuals over the age of 60 (although it can happen in younger individuals as well). Other risk factors can increase your chances of developing the disease such as:
• Smoking: Cigarette smoking can double your likelihood of developing AMD.
• Lifestyle: Research shows that UV exposure, poor nutrition, high blood pressure, obesity and a sedentary lifestyle can also be contributing factors.
• Gender: Females have a higher incidence of AMD than males.
• Medications: Certain medications may increase the chances of developing AMD.
• Genetics and Family History: Research shows that there are actually almost 20 genes that have been linked to AMD, and they suspect that there are many more genetic factors to be discovered. Family history greatly increases your chances of developing AMD.
• Race: Caucasians are more likely to get AMD than Hispanics or African-Americans.
How is Macular Degeneration Treated?
There is as yet no outright cure for age-related macular degeneration, but some treatments may delay its progression or even improve vision.
Treatments for macular degeneration depend on whether the disease is in its early-stage, dry form or in the more advanced, wet form that can lead to serious vision loss. No FDA-approved treatments exist yet for dry macular degeneration, although nutritional intervention may help prevent its progression to the wet form.
For wet AMD, treatments aimed at stopping abnormal blood vessel growth include injections of FDA-approved drugs called Lucentis, Eylea, Macugen and Visudyne used with Photodynamic Therapy or PDT. Lucentis has been shown to improve vision in a significant number of people with macular degeneration.