Are you seeing a fuzzy view of the world when it comes to the center of your vision? It may be because of age-related macular degeneration or AMD for short. It can start out as a small area of focus directly in front of you and slowly grow over the years or it can happen very fast, making it very difficult, if not impossible, to do normal things like read or cook. The blurred areas can eventually turn into blank spots.
Blue light
There are two wavelengths of light that can harm your eye. UV, or ultraviolet, can affect the front of your eye causing cataracts. Blue affects the back of the eye, or the macula. There are two kinds of blue light emitted: blue-violet and blue-turquoise.
The shorter wavelength blue violet light comes from more than just the sun. It can come from light emitting diodes (LEDs) or compact fluorescent lamps (CFLs). 25% percent of the CFL light is the damaging blue light while LEDs are more in the range of 35%. To make it worse, the ‘cooler’ the LED light you use, the higher the content of the blue light. With LEDs replacing more and more of our indoor lighting, the exposure will continue to increase. Keep in mind that LEDs also can include your televisions, tablets, cell phones and computer screens.
The longer wavelength blue-turquoise is actually very helpful. It helps establish our sleep cycles
The Macula
The macula is in the back of your eye near the retina. Consider it to be the movie screen and your lens the movie projector. Your central vision comes from this area of your eye. The macula consists of millions of cells that turn the light shone on them into electrical signals that are sent to the brain. From there, the brain translates those signals into an image that you can ‘see’. If something happens to the macula, your central vision will become blurred. Blue-violet light can damage the cells of the macula.
What are the other risks that make us more susceptible?
Age is the major risk. Most people develop AMD at the age of 50 or later, though it can appear earlier.
Smoking is the one risk we can do something about. If you smoke, you at least double your chances of getting AMD. Some reports say up to ten times more likely.
Two other factors exist before we are born. One is our DNA. If your parents or grandparents had AMD, your chance of developing the condition just increased. The other factor is race. Caucasians are diagnosed with AMD more often than those of African, Hispanic or Latino genetics. If you are susceptible, you can ask your doctor for genetic testing.
What kind of tests for AMD are there?
There are several. The first one you might experience is the eye chart. It helps the doctor understand how you are able to see from distances.
Another test is to have your eyes dilated. This relaxes your iris allowing the doctor easier access to see the back area, or macular, part of your eye.
The Amsler Grid is a test where you gaze at a grid of lines. If the center of the grid is wavy or out of focus, it may be because of macular degeneration.
The Fluorescein angiogram injects dye into your body and an ophthalmologist will take pictures as the fluorescent dye passes through your eye’s blood vessels.
Optical coherence tomography (OCT) uses light the way ultrasound uses sound to map the eye.
Drusen
Drusen may be the first sign of AMD for your doctor to see. Drusen is a small deposit in a layer under the retina called the Bruch’s membrane. It can be hard or soft. Hard appears as calcified deposits. Soft can appear amorphous and are larger. Further tests can confirm if it is AMD and what stage the disease is in.
Stages
Early AMD does not affect the vision yet but it is the first stage of the disease. There is no cure at this time but there are steps you can take to slow the progress. If you smoke, stop. It is that simple. Talk to your doctor about healthy exercise. Studies show that fit patients develop at a slower rate. Also, eat nutritiously. Leafy vegetables and fish are especially helpful.
If your doctor finds that you have Intermediate AMD or late AMD in just one eye, there are further steps on which he can advise you. Tests have shown that a certain mixture of doses of the following can be helpful in slowing down the degeneration: vitamin C, vitamin E, zinc oxide, cupric oxide and beta-carotene. Some of these you can find naturally in leafy green vegetables and fish. Check with your doctor to see what combinations will work best for you and which ones to avoid.
Advanced neo-vascular AMD can bring on severe vision loss. There is still no cure at this stage and the best you can hope for is to slow down the progress so you can enjoy your vision for a longer period of time. At this stage, your doctor may have you take injections in your eye. A protein called vascular endothelial growth factor (VEGF) increases in your eye and your doctor wants to limit its presence. If your doctor puts you on this treatment, it is very important to follow his instructions on any prescribed antibiotic drops.
Another step for this late stage could be photo-dynamic therapy. Part of the degeneration comes from the growth of new abnormal blood vessels in your eye. With this procedure, the doctor injects a drug called Verteporfin into your blood stream. Your doctor will watch the drug course to the eye. He will then aim a ‘cool’ laser at selected abnormal blood vessels and target the drug in those vessels. This action will inhibit the growth of those abnormal vessels and you will likely have your vision for a longer period of time.
Laser surgery is another important treatment in late stage AMD. This will take a ‘hot’ laser and target the abnormal vessels in your eye. Instead of slowing their growth, the laser destroys the abnormal vessel. This can work if the abnormal vessels are easily targeted. Use of this technique can destroy surrounding tissue and may make your vision worse than before the surgery but, it can also stop more severe vision loss down the road.
None of these procedures will cure AMD. The best you can hope for is to slow down the degeneration. The best step anyone can take is one of prevention. With the added factor of blue light mentioned before, there are now glasses using a filter that blocks most of the harmful blue-violet and allows the beneficial blue-turquoise into your eyes. Essilor and the Paris Vision Institute have developed the lens. Traditional blue blockers will also block the harmful violet blue rays but they also block the good blue-turquoise rays. It is hopeful that with this new discovery, more potential AMD sufferers will get help.
Information from The Review of Optometry and the National Eye Institute were very helpful in constructing this article.
