Age-related macular degeneration– also called macular degeneration, AMD or ARMD– is wear and tear of the macula, which is the little main area of the retina of the eye that manages visual skill.
The health of the macula determines our ability to check out, acknowledge faces, drive, view tv, use a computer system, and perform any other visual job that needs us to see fine detail.
Age-Related Macular Degeneration Understanding
Macular degeneration is the leading reason for vision loss amongst older Americans, and due to the aging of the U.S. population, the number of people impacted by AMD is expected to increase considerably in the years ahead.
In 2010, approximately 2.07 million Americans had advanced age-related macular degeneration, which number is expected to grow to 5.44 million in 2050.
AMD is most typical 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 impacted more frequently than blacks, non-white Hispanics and other ethnic groups (2.5 percent vs. 0.9 percent).
Wet And Dry Forms Of Macular Degeneration
Macular degeneration is detected as either dry (non-neovascular) or wet (neovascular). Neovascular describes development of new members vessels in an area, such as the macula, where they are not supposed to be.
The dry kind is more typical than the damp kind, with about 85 to 90 percent of AMD patients diagnosed with dry AMD. The damp type of the disease normally 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, transferring of pigment in the macula or a mix of the two procedures.
Dry macular degeneration is identified when yellowish spots referred to as drusen start to accumulate around the macula. It is thought these spots are deposits or debris from deteriorating tissue.
Gradual main vision loss may accompany dry macular degeneration however generally is not nearly as severe as damp AMD symptoms. Nevertheless, dry AMD through a period of years gradually can advance to late-stage geographic atrophy (GA)– gradual degradation of retinal cells that likewise can cause severe vision loss.
No FDA-approved treatments are available for dry macular degeneration, although a few now are in medical trials.
Two large, five-year scientific trials– the Age-Related Eye Disease Study (AREDS; 2001) and a follow-up study called AREDS2 (2013)– have shown nutritional supplements consisting of antioxidant vitamins and multivitamins that also contain lutein and zeaxanthin can minimize the risk of dry AMD advancing to sight-threatening wet AMD.
However neither the AREDS nor the AREDS2 research study showed any preventive benefit of dietary supplements against the development of dry AMD in healthy eyes.
Currently, it appears the best way to secure your eyes from establishing early (dry) macular degeneration is to eat a healthy diet, workout and wear sunglasses that protect your eyes from the sun’s harmful UV rays and high-energy visible (HEV) radiation.
Wet macular degeneration (neovascular). In about 10 percent of cases, dry AMD advances to the advanced and harmful kind of the eye disease. With wet macular degeneration, new members vessels grow beneath the retina and leak blood and fluid. This leak causes irreversible damage to light-sensitive retinal cells, which die off and develop blind spots in central vision.
Choroidal neovascularization (CNV), the underlying procedure causing wet AMD and unusual blood vessel growth, is the body’s misguided method of trying to produce a brand-new network of capillary to provide more nutrients and oxygen to the eye’s retina. Rather, the procedure produces scarring, causing often severe main vision loss.
Wet macular degeneration falls into two classifications:
- Occult. New blood vessel development beneath the retina is not as noticable, and leakage is less apparent in the occult CNV form of wet macular degeneration, which usually produces less severe vision loss.
- Classic. When blood vessel growth and scarring have extremely clear, defined describes observed underneath the retina, this kind of wet AMD is referred to as classic CNV, generally producing more severe vision loss.
Age-Related Macular Degeneration Symptoms And Signs
Age-related macular degeneration normally produces a slow, pain-free loss of vision. In unusual cases, nevertheless, vision loss can be abrupt. Early signs of vision loss from AMD include shadowy areas in your main vision or uncommonly fuzzy or distorted vision.
Viewing a chart of black lines organized in a chart pattern (Amsler grid) is one method to inform if you are having these vision problems. See how an Amsler grid works by taking a macular degeneration test.
Eye care professionals often spot early signs of macular degeneration before symptoms take place. Typically this is accomplished through a retinal exam. When macular degeneration is presumed, a short test utilizing an Amsler grid that measures your central vision might be carried out.
If your eye doctor finds some defect in your main vision, such as distortion or blurriness, he or she might purchase a fluorescein angiography to examine the retinal capillary surrounding the macula.
What Causes Macular Degeneration?
Though macular degeneration is associated with aging, research recommends there also is a genetic element to the disease. Duke University and other researchers have kept in mind a strong association between development of AMD and presence of a variant of a gene called complement factor H (CFH). This gene deficiency is associated with nearly half of all possibly blinding cases of macular degeneration.
Columbia University Medical Center and other detectives discovered that variations of another gene, complement element B, might be associated with advancement of AMD.
Specific versions of one or both of these genes, which play a role in the body’s immune actions, have been discovered in 74 percent of AMD patients who were studied. Other complement elements also may be connected with an increased risk of macular degeneration.
Other research has shown that oxygen-deprived cells in the retina produce a kind of protein called vascular endothelial growth factor (VEGF), which activates the development of new blood vessels in the retina.
The normal function of VEGF is to develop new members vessels during embryonic development, after an injury or to bypass obstructed blood vessels. However too much VEGF in the eye causes the advancement of unwanted capillary in the retina that easily break open and bleed, damaging the macula and surrounding retina.
Who Gets Age-Related Macular Degeneration?
Besides affecting older populations, AMD occurs in whites and women in particular. The disease also can result as a side effect of some drugs, and it seems to run in households.
New proof strongly suggests cigarette smoking is high on the list of risk factors for macular degeneration. Other risk factors for macular degeneration include having a member of the family with AMD, high blood pressure, lighter eye color and obesity.
Some scientists think that over-exposure to sunshine likewise might be a contributing consider development of macular degeneration, however this theory has not been shown conclusively. High levels of dietary fat also may be a risk element for developing AMD.
Commonly called risk factors for establishing macular degeneration include:
- Aging. Substantial vision loss accompanying advanced forms of AMD increases from fewer than 1 percent among people in their 60s to more than 15 percent amongst individuals in their 90s, according to the Canadian Medical Association Journal (February 2004).
- Weight problems and lack of exercise. Obese patients with macular degeneration had more than double the risk of establishing sophisticated types of macular degeneration compared to people of normal body weight, according to one research study reported in Archives of Ophthalmology (June 2003). In the same study, those who carried out energetic activity at least three times weekly decreased their risk of developing advanced AMD, compared with non-active patients.
- Heredity. As mentioned above, current studies have discovered that particular versions of various genes are present in many people who have macular degeneration. Research studies of fraternal and twins might also demonstrate that heredity is a factor in who establishes AMD and how severe it becomes.
- Hypertension (High blood pressure). Investigative Ophthalmology and Vision Science reported the outcomes of a European research study demonstrating that hypertension might be related to advancement of macular degeneration.
- Smoking. Smoking cigarettes is a significant AMD risk element and was discovered in one British study to be straight associated with about 25 percent of AMD cases causing severe vision loss. The British Journal of Ophthalmology in early 2006 also reported research study findings showing that individuals dealing with a cigarette smoker double their risk of developing AMD.
- Lighter eye color. Because macular degeneration long has been believed to happen more frequently among Caucasian populations, particularly in people with light skin color and eye color, some scientists theorized that the extra pigment found in darker eyes was a protective factor against development of the eye disease during sun exposure. But no conclusive proof as yet has linked excessive sun direct exposure to advancement of AMD.
A little research study reported in the British Journal of Ophthalmology (January 2006) found no connection between the eye disease and sun exposure. In reality, the exact same research study found no relation at all in between lighter eye color, hair color and AMD. That finding is contradicted by a number of earlier studies indicating that lighter skin and eyes are connected with a greater occurrence of AMD.
- Drug side effects. Some cases of macular degeneration can be caused from side effects of hazardous drugs such as Aralen (chloroquine, an anti-malarial drug) or phenothiazine. Phenothiazine is a class of anti-psychotic drugs, consisting of brand names of Thorazine (chlorpromazine, which likewise is used to treat nausea, vomiting and persistent hiccups), Mellaril (thioridazine), Prolixin (fluphenazine), Trilafon (perphenazine) and Stelazine (trifluoperazine).
The American Academy of Ophthalmology notes that findings regarding AMD and risk factors have been inconsistent, depending on the study. The only risk factors regularly found in research studies to be associated with the eye disease are aging and cigarette smoking.
There is yet no outright cure for age-related macular degeneration, but some treatments may delay its progression or perhaps improve vision.
Treatments for macular degeneration depend upon whether the disease is in its early-stage, dry kind or in the more advanced, wet type that can lead to serious vision loss. No FDA-approved treatments exist yet for dry macular degeneration, although nutritional intervention may help avoid its progression to the damp type.
For damp AMD, treatments focused on stopping unusual blood vessel development include FDA-approved drugs called Lucentis, Eylea, Macugen and Visudyne used with Photodynamic Therapy or PDT. Lucentis has actually been shown to improve vision in a substantial number of individuals with macular degeneration. [For more details, read our short article about macular degeneration treatments.]
Nutrition And Macular Degeneration
Numerous organizations and independent scientists are performing studies to identify if dietary modifications can minimize an individual’s risk of macular degeneration and vision loss associated with the condition. And a few of these studies are revealing positive associations in between excellent nutrition and lowered risk of AMD.
For instance, some studies have actually suggested a diet that includes plenty of salmon and other coldwater fish, which consist of high amounts of omega-3 fatty acids, might assist prevent AMD or minimize the risk of its progression.
Other research studies have actually shown that supplements including lutein and zeaxanthin increase the density of pigments in the macula that are associated with safeguarding the eyes from AMD.
See and bookmark our Eye Nutrition News page for the current advancements in nutritional research that might avoid or limit vision issues from AMD, cataracts and other eye conditions.
Evaluating And Low Vision Devices For Age-Related Macular Degeneration Treatment
Although much progress has been made just recently in macular degeneration treatment research, total recovery of vision lost to AMD is unlikely.
Your optometrist might ask you to check your vision frequently with the Amsler grid described above.
Seeing the Amsler grid separately with each eye helps you monitor your vision loss. The Amsler grid is a very sensitive test and it may expose main vision issues before your eye doctor sees AMD-related damage to the macula in a routine eye exam.
For those who have vision loss from macular degeneration, lots of low vision devices are readily available to help with movement and specific visual jobs.