Macular degeneration refers to aging of the retinal tissue which comprises the macula. The macula is the area of the retina that provides us with our central vision. When the cells of the macula degenerate it causes blurriness or darkness in our central vision. This is very different from other disease processes, such as glaucoma, which causes visual damage mainly in the periphery. Fortunately, macular degeneration does not tend to affect the side or peripheral vision. Macular degeneration only rarely causes total blindness since it tends to preserve the valuable side vision which allows people to take care of themselves in most cases
Causes of macular degeneration.
Macular degeneration may be secondary to a lifelong exposure to the sun’s ultraviolet rays or to other hereditary or dietary factors. It is much more common in patients with northern European ancestry. It is less common in African Americans and Hispanics. In most cases macular degeneration is considered an aging process and is sometimes referred to as “age related macular degeneration” or ARMD. The two most common types of ARMD are “dry” (atrophic) and “wet” (exudative):
“Dry” macular degeneration (atrophic)
This is the most common type of macular degeneration and does not involve any bleeding behind the retina. Vision loss is usually very gradual and occurs over many years.
“Wet” macular degeneration (exudative)
“Wet” macular degeneration accounts for about 10% of all cases. It results when abnormal blood vessels form in the macula and bleed into the retinal tissues. It is the bleeding and scarring process that can then result in visual loss. Wet macular degeneration can cause vision to decline much more rapidly than the dry type. The loss of vision with wet macular degeneration is usually more severe than with the dry type.
What are the symptoms of macular degeneration?
The symptoms differ widely. In some cases the central vision becomes markedly worse and patients may no longer be able to see the central part of their reading material. In other cases one may note wavy or distorted vision around straight lines. Often, if only one eye is affected, one may not notice that anything is wrong at all.
How is macular degeneration diagnosed?
Regular eye exams are crucial in detecting and treating macular degeneration since most patients do not realize that they may have a problem. The eye exam will usually include a dilation of the pupil and careful ophthalmoscopy to check the macula. In some cases special photographs or angiograms may be taken. In addition, various scans may be done if needed to check for vessels or swelling behind the retina.
How is macular degeneration treated?
Currently, there is no cure yet for “dry” macular degeneration. Many in the field believe that nutritional supplements may slow macular degeneration and these are now routinely prescribed. Treatment of this condition focuses on helping a person find ways to cope with visual impairment.
In its early stages “wet” macular degeneration can be treated with laser surgery or injections into the eye. Both the laser and the injections attempt to stop the abnormal blood vessels from bleeding and proliferating. Over the last few years remarkable progress has been made in treating “wet” macular degeneration and many patients can now retain functional vision. However, regular eye exams are crucial in detecting new bleeding. As previously mentioned, nutritional supplements are also used in all cases. ,
Because side vision is usually not affected, a person’s remaining sight can be very useful. Often, people can continue with many of their favorite activities by using low vision optical devices such as magnifying devices, closed circuit television, large print reading materials, and talking or computerized devices. Low vision centers are available that can assist patients with the wide variety of devices available.
Testing your vision with the Amsler Grid
It is extremely important to supplement your visits to the doctor with a daily self testing routine. This is usually accomplished by using a small grid card called the Amsler grid. This test is composed of a perfect grid with straight lines and small squares. The grid should be placed in a location in which you are reminded to check it on a daily basis eg:. your refrigerator door, medicine cabinet etc. Checking the grid on a routine basis can alert you to problems that may signal worsening macular degeneration or new areas of abnormal bleeding. Be aware of how the grid looks like on a daily basis contact your doctor immediately if you notice any change.
Click HERE to download an Amsler grid:
Using the Grid:
1. Wear your reading glasses and look at the grid in good lighting.
2. Cover one eye. Look at the center with the uncovered eye.
3. When looking directly at the center dot, note whether the lines and squares of the grid are straight or if any areas are distorted, wavy, blurred or dark.
4. Now repeat this procedure with the other eye.
5. Call your eye doctor is there is any change in the appearance of the grid