Macular Degeneration – AMD
What is the Macula?
In the back of the eye is the retina which is analogous to the film of a camera. One small area of the retina, called the macula, is devoid of visible blood vessels and has the highest concentration of photo-receptors (light capturing cells). This is the area of the retina that accounts for visual acuity. The center of the macula is called the fovea. This small area of the retina is used when you look straight ahead. It is the area used to drive a car, read a book, and watch television.
What is Macular Degeneration?
Unfortunately, this very biologically active tissue is prone to damage with age. The disease is a degeneration process. It occurs more commonly in people that: are fair skinned, have high blood pressure, exposed to sunlight, smoke, and those without cataracts. There are two types of Age Related Macular Degeneration (ARMD): dry and wet. Dry is a slow insidious disturbance of the macular area with accompanying loss of vision. The dry type occurs most of the time (most common 90% of the time). The vision usually does not get very bad. The wet type is due to leakage of fluids and blood under and within the macula. The effect is often devastating. The wet type if caught early enough can be treated with a laser to seal the leaky areas.
The first sign of wet macular degeneration is a sudden distortion or wavy vision in one eye. If this occurs, there is a small window of time in which fluid is beginning to leak and a laser can stop the leakage with a minimum of damage. Laser at best is not a cure but a method of stabilizing vision. In most cases laser results in an initial decrease of vision, but compared to the devastating, long term effects of wet macular degeneration this is a benefit. Though, the dry form may also cause distortion the distortion is less severe and more insidious in its development.
How is the Diagnosis Made?
The diagnosis of Age Related Macular Degeneration (ARMD) can only be made with special instruments to examine the back of the eye known as the retina. Either dry macular degeneration or significant wet macular degeneration may be diagnosed by visual observation of the back of your eye during the dilation portion of your eye examination. However, subtle wet macular degeneration needs more sophisticated tests such as fluorescein angiography. Fluorescein angiography is performed by injecting a dye into the arm and photographing the passage of the dye through the arteries, capillaries and veins of the eye. If there is any leakage of fluid by the blood vessels, the dye will leak out of the vessels and be seen on the photographs taken during testing.
How Common is ARMD (Age Related Macular Degeneration)?
There are many types of ARMD with variable visual out comes. It effects 20% of those between 65-75 and 35% of patients older. There is no cure for ARMD, but there is help. Most cases are very mild with patients not even being aware of the problem.
I Have the Dry Type Will I Get the Wet Type?
Most patients with dry ARMD remain that way for years. However, patients with dry ARMD have a greater chance of developing the wet variety. That is why we suggest that you check your vision in each eye with the grid every day.
One of My Parents Has ARMD will I Get It?
There is a genetic predisposition to ARMD, thus, if your parents have it you have a better chance of getting it. However, if your parents have it, it doesn’t mean you will get it. We have not identified the gene for ARMD and do not know the mode of transmission.
Will I Go Blind From Macular Degeneration?
Fortunately, the visual loss though devastating does not cause complete blindness. Peripheral vision is intact and mobility is maintained. However, ARMD makes it difficult or impossible to drive, read, or watch TV. Patients with ARMD should evaluated for appropriate visual aids to improve the quality of life. Special glasses (magnifiers and telescopes) may be prescribed to magnify the print. Computers can be designed to enlarge print. Special viewing devices can enlarge print. Large print magazines and newspapers are available. Obviously, these devices are not a cure, but they sure help. The patient must be motivated to use them.
Do Vitamins Really Help?
Yes. Patients prone to ARMD should take vitamins such as Macular Protect Complete which contains zinc; Lutein , a naturally occurring carotenoid; and Beta Carotene. Lutein is an anti-oxidant which is believed to block the effects of UV light. These vitamins have been designed to slow the progression of ARMD especially in the dry type. Macular Protect Complete is available at all of our offices.
The National Eye Institute, a division of the National Institute of Health, released the results of an eight year study (JAMA Oct 2001). The study was performed on close to 3500 particiapants between the ages of 55 and 80. The subjects were divided in four groups: no ARMD, early ARMD, intermediate, and advanced ARMD. Subjects who were classified as having either intermediate or advanced ARMD and used high potency anti-oxidants with zinc and copper showed a small but real decrease in the progression of ARMD. There was no real effect with those patients who were in the no ARMD and early ARMD groups. If you are a smoker you should not take beta carotene, take zinc with copper only. Lutein was not available at the time of the study. Thus, we believe that the judicious use of vitamins is more likely to be beneficial than not.
Also, UV filters should be put in to all glasses used outside. These glasses should be used even on a cloudy day, since UV light passes through the clouds. Wearing a brimmed hat decreases further exposure to UV light. If you smoke you should stop and control your blood pressure (the silent killer) and cholesterol level.
What Should I Eat?
A diet beneficial for cardiovascular health is also good for the eyes – low in saturated fats, high in fruits and vegetables. Exercise is also important, since a healthy heart sends more nutrients and oxygen to the eyes. There is also evidence that dark leafy vegetables such as spinach, kale, and collard greens are helpful. A glass of red wine seems to be helpful. Stop smoking!
I Can’t Read With my Current Glasses, Can You Help?
Maybe yes, maybe no. We can only tell with an evaluation. Patients with reduced vision can often benefit from special glasses which magnify the print. This does not make it clearer but enlarges the print enough to see. These special glasses include: stronger lenses, telescopes, and/or microscopes. Strong hand held or table magnifiers may also be beneficial. Computer screens can be adjusted to change the font. Large print magazines and newspapers are available. Special closed circuit TV systems have been designed to enlarge print. In summary, there is help for the motivated patient.
How Should I Monitor My Vision?
Print out this grid pattern by clicking here to open this PDF document: Amsler Grid. Put it on the refrigerator or medicine cabinet. Look at it each day (16 inches from your eyes) one eye at a time. If the lines become distorted then come in immediately for an eye examination.
Instructions for using the grid
§ Use adequate lighting.
§ Wear your reading glasses or look through the reading portion of your glasses.
§ Hold the grid at reading distance (about 16 inches).
§ Cover one eye at a time.
§ Stare at the center dot of the chart at all times.
Ask yourself the following questions as you check each eye separately:
- Are any of the lines crooked or bent?
- Are any of the boxes different in size or shape from the others?
- Are any of the lines wavy, missing, blurry, or discolored?
If the answer to any of these questions is “yes”, you should contact this office immediately and schedule an examination. Sometimes these changes may mean that there is leakage or bleeding in the back of the eye causing swelling of the retina. Immediate laser treatment, when indicated, may prevent further devastating effects