Macular Degeneration

What is macular degeneration?
Macular degeneration is a condition that can cause loss of sight centrally.  This is the area of the eye that helps with detail vision and color vision. Macular degeneration almost never causes total blindness, however it is the major cause of loss of vision in people over fifty in our country. It is often referred to as age-related macular degeneration (AMD or ARMD). There are different forms of macular degeneration such as the dry form, the wet form and there are also some juvenile forms of macular degeneration as well although, they are much less common.  In order to understand more about macular degeneration, you must first understand how the eye works.

The macula allows us to see tiny detail, to read
fine print, recognize faces,thread a needle,
read the time, see street signs, etc.

The eye is like a camera. When you take a picture the lenses in the front of the camera allow light through and focus that light on the film that covers the back inside wall of the camera. When the light hits the film, a picture is taken.  The eye works much the same way.  The front parts of the eye (the cornea, the pupil, and the lens) are clear and allow light through.  The cornea and lens focus that light on the back inside wall of the eye.  A thin layer of tissue called the retina covers the back inside wall of the eye.  The retina is like the film in a camera. It is the seeing tissue. When the focused light hits the retina, a picture is taken. Messages about this picture are sent to the brain through the optic nerve.  The brain then interprets these messages and this is how we see.  The choroid is the blood vessel layer under the retina. The retina receives some of its nutrition and oxygen from the choroid. The retina has two parts: the peripheral retina and the macula. If you imagine the retina as a circle with a bull’s eye at the center, the macular is like the bull’s-eye: it is very small. It is located near the optic nerve.  The large area of the retina that surrounds the macula and makes up 95% of the retina is called the peripheral retina.  The peripheral retina gives us vision to the side, this is called peripheral vision. This is what we refer to when we say, “I saw something out of the corner of my eye.”  Because the peripheral retina cannot see detail clearly, we cannot use peripheral vision to read, thread a needle, drive, or even recognize a face. If I see someone off to my side, “out of the corner of my eye”, I may be able to tell who the person is by his or her general shape, but I won’t be able to see the expression on that person’s face.

Who develops macular degeneration?
Macular degeneration is most often related to aging. There are some unusual types that start very early in life. Most patients with macular degeneration begin to notice problems with eyesight sometime after the age of fifty. There are some studies that indicate there is a higher incidence of macular degeneration in fairer individuals with blue eyes. This is thought to be related to less protective dark pigment in lighter colored eyes. There is a higher incidence of macular degeneration in females than males. Macular degeneration is often hereditary and therefore can run in families. If you have macular degeneration, your blood relatives should have an eye exam every year or two after age fifty.

Are there other risk factors for developing macular degeneration besides the hereditary link?
It has been shown that besides aging, smoking, hypertension, lighter eye color, a poor diet and or obesity can contribute to macular degeneration.

Normal


Abnormal

How do I know if my central vision is distorted?
There is a test that is called the amsler grid. An example of an amsler grid is shown below. You may also go to our eyebrary section on this website and click on graph like paper under the first definition which is amsler grid in the a-h category. This will allow you to open up a full page amsler grid. You can print this grid for yourself or a family member. If you have a history of macular degeneration, test your eyes once or twice a week to see if there are any new changes on the grid. This is a quick way for a patient to monitor their central visual acuity by covering one eye at a time and checking their vision. This test is done up close, one eye at a time and is done with your glasses on if you normally wear them for your near vision.  The lines should appear nice and linear (not wavy) with no gray, brown or blurry spots covering part of the grid. Another example of an abnormal amsler grid can be found at this link: www.allaboutvision.com/conditions/amd.htm.

If a patient develops a new distortion in their central vision such as a new area of wavy lines, blurred out or dark area on the grid as though a portion of the grid is missing centrally, they should be checked right away.

Wet macular degeneration	Scarring after wet macular degeneration

How may I get my other questions answered about macular degeneration such as treatment options, vitamin or nutrition therapy and the many different forms of macular degeneration?
Because there is a wealth of information on the internet now, there are many foundations and medical sites that have much information.  These sites will explain large studies done such as the AREDS (Age Related Eye Disease Study) which looked at vitamins and daily nutrition and this impacts macular degeneration. These sites also review the difference between dry and wet macular degeneration and the rare forms of macular degeneration such as the juvenile forms of macular degeneration. They list latest trials or medical therapies that are being investigated currently as well as treatments that are already FDA approved. We have provided the names of these sites below so that if you would like to have additional information on macular degeneration, you may research further.

These sites are:
www.nei.nih.gov/health/maculardegen/armd_facts.asp
www.eyecarefoundation.org/research.htm
www.macular-degeneration.org
/www.ahaf.org/macular/
www.blindness.org
www.amd.org
www.amd.org/site/PageServer?pagename=Focus_090199
www.asb.org

Am I a candidate for low vision services? Patients that have macular degeneration are frequently good candidates for low vision as they may need to use another area of their retina to look around their central visual defect. 
They also may need some type of low vision device to help with contrast. Specialty devices such as magnifiers, special T.V. devices, computer devices, may indeed enhance their life allowing them to participate in visual activities that without these devices would not be possible.  Eye Associates does offer low vision evaluations with Dr. Micah Brienen. A special appointment is required for this evaluation to specifically try certain devices.  A recent eye exam is also required to make sure the eye is evaluated for other problems prior to this service. A patient may be referred to Dr. Brienen for this service and may have their last eye exam notes forwarded to Eye Associates of Tallahassee.