Can vitamin supplements help treat dry age-related macular degeneration? [ 11/04/14 ]
Once dry age-related macular degeneration reaches the advanced stage, there is no form of treatment at present to prevent further vision loss. However, there is an intervention measure that could delay and possibly prevent intermediate age-related macular degeneration from progressing to the advanced stage in which vision loss occurs.
The National Eye Institute’s Age-Related Eye Disease Study (AREDS) found that taking nutritional supplements with a specific high-dose formulation of antioxidants (vitamins C and E and beta-carotene), zinc, and copper delayed or prevented the progression of age-related macular degeneration from the intermediate to the advanced stage.
A follow-up trial, called AREDS2, was completed in May 2013. In that study, researchers found that the addition of omega-3 fatty acids to the supplements did not improve the formula’s success. The antioxidants lutein and zeaxanthin proved safer than beta-carotene, which increases the risk of lung cancer for smokers or ex-smokers. Thus, the AREDS2 recommendation for the supplement formula is 500 milligrams of vitamin C, 400 international units of vitamin E, 10 milligrams of lutein, 2 milligrams of zeaxanthin, 80 milligrams of zinc, and 2 milligrams of copper.
What is an Amsler grid? [ 11/04/14 ]
To discover any changes to your vision as early as possible, your eye care professional will probably have you test your own vision on a regular schedule using a small, hand-held Amsler grid. He or she may also do this at the office. At home, you will hold the chart at reading distance in good light, cover one eye, and focus on a black dot in the middle of the grid, then repeat with the other eye. If the lines of the grid appear dim, irregular, wavy, or fuzzy, you should schedule an eye exam immediately.
You can download an Amsler grid at www.brightfocus.org/amsler.
How is age-related macular degeneration (AMD) diagnosed? [ 11/04/14 ]
To help diagnose AMD, an eye care professional will perform a dilated eye exam to view the retina and optic nerve for damage, a visual acuity test to measure sight from various distances and a fundoscopy to examine the back of the eye. If wet AMD is suspected, fluorescein angiography, in which dye is used to detect leaking blood vessels, may also be performed. The patient might be asked to look at Amsler grid; if the straight lines on the grid appear wavy or distorted, AMD may be developing.
Is age-related macular degeneration (AMD) hereditary? [ 11/04/14 ]
Age-related macular degeneration (AMD) typically affects individuals over 50 years old. Scientific evidence shows that genes may play a role in the development of nearly three out of four cases of this devastating eye disease.
Several genes are believed to be strongly associated with the risk of developing AMD:
- Factor H and Factor B genes are responsible for proteins that help regulate inflammation in the part of the immune system that attacks diseased and damaged cells. According to study results published in 2006 by Columbia University, 74 percent of AMD patients carry certain variants in one or both of these genes, and these may significantly increase their risk of developing it.
- PLEKHA1 – a gene located on chromosome 10; researchers believe it may increase the risk of developing AMD. Like Factors H and B, PLEKHA1 appears to be involved in the cellular processes related to inflammation.
- LOC387715 – A certain variation of this gene appears to increase the risk of developing AMD. This risk is further heightened if a person with this gene variation also smokes.
- HTRA1 – Scientists have identified a link between a mutation in this gene and the development of AMD. Specifically, the HTRA1 mutation is thought to be associated with the formation of drusen (yellow deposits of waste products under the retina that are often a sign of dry AMD), and may also promote the growth of fragile new blood vessels typical of wet AMD.
- Complement C3 – Researchers have found that a variant in this gene increases the risk of developing the wet and dry forms of AMD. This gene plays an important role in the immune system, leading scientists to believe that inflammation is a vital part of the AMD disease process.
Other gene candidates are being studied to determine their role in AMD. While there is definitely a strong genetic component to this disease, it is highly likely that its development is due to a combination of multiple factors including gene mutations or variations and environmental factors such as sunlight exposure, diet and smoking.
Can you get age-related macular degeneration (AMD) in only one eye or does it usually occur in both? [ 11/04/14 ]
It is possible to develop AMD in only one eye. However, as the disease progresses both eyes may become affected. If an individual has macular degeneration in one eye, he or she is more likely to develop it in the other eye than someone who does not.
What is age-related macular degeneration (AMD)? [ 11/04/14 ]
AMD is a common eye disease associated with aging that gradually destroys sharp, central vision. The retina is the very thin tissue that lines the back of the eye and contains the light-sensing cells that send visual signals to the brain. Sharp, clear, 'straight ahead' vision is processed by the macula, which is the central part of the retina. When the macula is damaged, many daily activities such as driving, reading and recognizing faces become increasingly difficult.
Do people with macular degeneration ever have visual hallucinations? [ 11/04/14 ]
Yes, some people with macular degeneration also develop Charles Bonnet Syndrome (CBS) and hallucinate. Some eye diseases prevent normal nerve impulses from reaching the brain, and it is believed that spontaneous, brain-generated nerve activity may cause visual hallucinations. CBS appears to be more common in women than men and is more likely to occur if both eyes are affected by disease. The hallucinations are normally complex and can include detailed patterns or fully formed images such as animals, people, faces or scenery. Patients know that the hallucinations are not real. These images are not associated with any other sensory (e.g., sound or odor) hallucinations, nor are they delusions. The hallucinations may last for seconds or for most of the day. They tend to disappear when people close their eyes. CBS may last for days or even years, but can be managed by educating the patient and reassuring him or her that the images are a result of eye disease, not a mental disorder.
Do wet and dry age-related macular degeneration (AMD) have early, intermediate and advanced stages? [ 11/04/14 ]
All wet AMD is considered advanced; however, the dry form of AMD has three stages:
- Early AMD - patients have several small drusen or a few medium-sized drusen. There is no vision loss or symptoms at this stage.
- Intermediate AMD - patients have many medium-sized drusen or one or more large drusen. Some people may need more light for tasks such as reading. A blurry spot may appear in the center of the visual field.
- Advanced AMD - patients exhibit a large number of drusen deposits and a breakdown of RPE and photoreceptor (light sensitive) cells and supporting tissue in the retina. A large blurry spot occurs in the center of the visual field and can become larger and darker, eventually causing a complete loss of central vision.