AMD or ARMD is deterioration of the macula, which is the small central area of the retina of the eye that controls . AMD is a chronic degenerative or dystrophic disease. The health of the macula determines our ability to read, recognize faces, drive, watch television, use a computer, and perform any other visual task that requires us to see fine detail.
Macular degeneration is the leading cause of vision loss among older Americans, and due to the aging of the U.S. population, the number of people affected by AMD is expected to increase significantly in the years ahead. AMD is the commonest cause of legal blindless in the USA and UK.
AMD is that in many cases is familial and inherited as an autosomal- dominanat triat. Although the average age of patients when they lose central vision in the first eye is 65 years of age, some patients develop evidence of the disease in the fourth and fifth decades of life. AMD is most common among the older white population, affecting more than 14 percent of white Americans age 80 and older. Among Americans age 50 and older, advanced macular degeneration affects 2.1 percent of this group overall, with whites being affected more frequently than blacks, non-white Hispanics and other ethnic groups.
Wet And Dry Forms Of Macular Degeneration
Macular degeneration is diagnosed as either dry (non-neovascular) or wet (neovascular).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 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 begin to accumulate in and around the macula. It is believed these spots are deposits or debris from deteriorating tissue. Gradual central vision loss may occur with dry macular degeneration but usually is not nearly as severe as wet AMD symptoms. However, dry AMD through a period of years slowly can progress to late-stage geographic atrophy (GA) — gradual degradation of that also can cause severe vision loss. Two large, five-year clinical trials — the Age-Related Eye Disease Study (AREDS; 2001) and a follow-up study called AREDS2 (2013) — have shown nutritional supplements containing vitamins and multivitamins that also contain and can reduce the risk of dry AMD progressing to sight-threatening wet AMD. Currently, it appears the best way to protect your eyes from developing early (dry) macular degeneration is to eat a healthy diet, exercise and that protect your eyes from the sun’s and .
Wet macular degeneration (neovascular). In about 10 percent of cases, dry AMD progresses to the more advanced and damaging form of the . 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. (CNV), the underlying process causing wet AMD and abnormal blood vessel growth, is the body’s misguided way of attempting to create a new network of blood vessels to supply more nutrients and oxygen to the eye’s retina. Instead, the process creates scarring, leading to sometimes severe central vision loss.
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 your central vision or unusually fuzzy or distorted vision. Viewing a chart of black lines arranged in a graph pattern () is one way to tell if you are having these vision problems. See how an Amsler grid works by taking a . often detect early signs of macular degeneration before symptoms occur. Usually this is accomplished through a retinal exam. When macular degeneration is suspected, a brief test using an Amsler grid that measures your central vision may be performed.
If your eye doctor detects some defect in your central vision, such as distortion or blurriness, he or she may order a to examine the retinal blood vessels surrounding the macula.
Who Gets Age-Related Macular Degeneration?
Besides affecting older populations, AMD occurs in whites and females in particular. The disease also can result as a side effect of some drugs, and it seems to run in families. New evidence strongly suggests is high on the list of risk factors for macular degeneration. Other risk factors for macular degeneration include having a family member with AMD, high blood pressure, lighter and obesity. Some researchers believe that over-exposure to sunlight also may be a contributing factor in development of macular degeneration, but this theory has not been proven conclusively. High levels of dietary fat also may be a risk factor for developing AMD.
How Macular Degeneration Is 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 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. [For more details, read our article about .]
Nutrition And Macular Degeneration
Many organizations and independent researchers are conducting studies to determine if dietary modifications can reduce a person’s risk of macular degeneration and vision loss associated with the condition. And some of these studies are revealing positive associations between good nutrition and reduced risk of AMD. For example, some studies have suggested a diet that includes plenty of salmon and other coldwater fish, which contain high amounts of , may help prevent AMD or reduce the risk of its progression .
Other studies have shown that supplements containing lutein and zeaxanthin increase the density of pigments in the macula that are associated with protecting the eyes from AMD .