The US National Institutes of Health (NIH) is due to announce the results of a nationwide study during 2013. The study aimed to determine if a modified combination of vitamins, minerals, and fish oil can slow the progression of vision loss from AMD, the leading cause of vision loss in the United States for people over age 60.
This study, called the Age-Related Eye Disease Study 2 (AREDS2), builds upon results from an earlier Age-Related Eye Disease Study (AREDS).
The original study found that high-dose antioxidant vitamins and minerals (vitamins C and E, beta-carotene, zinc, and copper), taken by mouth, reduced the risk of progression to advanced AMD by 25 percent, and the risk of moderate vision loss by 19 percent. AREDS2 will refine the findings of the original study by adding lutein and zeaxanthin (plant-derived yellow pigments that accumulate in the macula, the small area responsible for central vision near the centre of the retina) and the omega-3 fatty acids DHA and EPA (derived from fish oils) to the study formulation. The main study objective is to determine if these nutrients will decrease a person's risk of progression to advanced AMD, which often leads to vision loss. Previous observational studies have suggested these nutrients may protect vision.
Lutein and zeaxanthin are found naturally in foods such as eggs, kale, spinach, romaine lettuce, broccoli, sweet corn, garden peas and Brussels sprouts. To maximise the availability of the carotenoids the foods should be eaten raw or lightly steamed. However nutritional supplements will provide higher doses more readily.
Some optometrists also recommend using yellow tinted ‘gaming’ sunglasses when using a computer for extended periods of time.
Increasingly optometrists are investing in equipment, such as the Macular Pigment Screener (MPSII), that can measure the thickness of the macular pigment. This can indicate who is most at risk of developing AMD and therefore would benefit from nutritional supplements.
There are a number of factors that increase the risk of developing AMD as follows:
If you have one or more of the above factors are relevant to you, then screening for AMD is recommended.
The macular is a small and very sensitive region of the retina responsible for clear central vision. Damage to this area over time is known as 'age-related macular degeneration' (AMD) and is characterised by a loss of central vision.
As the disease progresses, it blurs the patient's central vision – creating the illusion of a ‘hole’. This may mean that when the patient looks directly at someone, they are able to see the person's hair and clothes but not their face. Although the precise cause remains unknown, it is thought that exposure to 'blue light' - a type of high-energy visible light emitted by the sun - is an important factor.
The role of the macula is to filter out harmful blue light before it hits the sensitive cells (known as the rods and cones) of the retina. As a person gets older, the risk of AMD increases, particularly when coupled with poor diet, smoking and drinking which can accelerate the onset of the disease.
AMD can take two forms, wet and dry. Wet AMD is caused by the abnormal growth of blood vessels under the macula, this leads to rapid loss of central vision. Wet AMD is considered to be advanced AMD and is more severe than the dry form. Dry AMD, the more common form, occurs when the light-sensitive cells in the macula slowly break down over time. Untreated dry AMD can progress into wet AMD.
According to the National Eye Institute (NEI) at the US National Institutes of Health (NIH), nearly two million Americans have vision loss from advanced AMD, and another seven million with AMD are at substantial risk for vision loss. It is thought that the AREDS vitamin and mineral formulation could save more than 300,000 people from vision loss over the next five years.
For more information, visit the NEI Website.