Macular Degeneration

Macular Degeneration is most often related to aging (AMD:  Age-Related Macular Degeneration).  There are some unusual types of macular degeneration that start very early in life.  However, most patients with macular degeneration begin to notice problems with eyesight sometime after age 50.  Macular degeneration is probably, in part, hereditary and therefore often runs in families.  If you have age-related macular degeneration, your blood relatives should have a retinal examination every year or two after age 50.

Macular Degeneration usually starts with the appearance of spots in the macula.  These spots are called drusen.  Drusen do not usually change vision very much themselves and only a few people with drusen develop severe macular degeneration with loss of vision. 

  

When macular degeneration does lead to loss of vision, that loss usually starts in just one eye and only later may affect the other eye.  In some, it never affects the vision of the second eye.  When a person loses vision from macular degeneration in one eye, the loss of vision may not even be noticed because the healthy eye can still see detail (such as read, drive, thread a needle, etc.).  It is only when macular degeneration severely affects both eyes that it will become difficult, or perhaps impossible, to do the kind of work that requires central vision, vision that can discern fine detail. 

 

In general, it is important to discover any change in eyesight as early as possible because the chance that treatment will help is greatest in the early stages of any eye problem.  That is why you should test the eyesight in each eye, each day, especially if your doctor has told you that you have drusen or early macular degeneration.

 

A person with severe macular degeneration, who has lost the ability to see detail with each eye, rarely loses peripheral vision and will still be able to get along fairly well.  It is very rare for someone with macular degeneration to lose both macular (detail) and peripheral (side) vision.  Macular degeneration almost never causes total blindness.  Almost all people with severe macular degeneration in each eye can see well enough to take care of themselves and continue those activities that do not require detail vision.

 

People with macular degeneration in each eye usually learn to make use of the areas just outside the macula to see detail better.  This ability to look slightly off center usually improves with time, although eyesight will never be as good as it was before the macula was damaged.  Once the macula has been severely damaged, treatment is usually no longer possible.  For this reason, everyone should test the vision in each eye- separately- each day.

 

One way to test the central vision in order to detect even the smallest changes when they first appear is to use the Amsler grid.  If you note any changes you should see your eye doctor promptly.

Instructions on using the Amsler grid:

1.)  Wear your reading glasses (if applicable)
2.)  Cover one eye
3.)  Look at the center dot and keep your eye focused on it at all times
4.)  While looking directly at the center, and only the center, be sure that all the lines are straight and all the small squares are the same size   
5.)  If you should notice any area on the grid that becomes distorted, blurred, discolored, or otherwise abnormal, please call your eye doctor right away.
6.)  Do this test for each eye separately.

This test should take very little time.
___________________________________________________________

Symptoms of Macular Degeneration

In the earliest stages of macular degeneration, vision may become blurred for distance or for reading, or both.

A very frequent and important symptom is distortion.  Straight lines will not look straight.  A telephone pole or a door frame may seem a little bent, crooked, or irregular, as though seen through heat waves on a highway.  An area of the Amsler grid will appear distorted and the small boxes in that area will vary in shape and size to the aftereffect caused by a flashbulb.  There may be other changes in vision:  you may notice that the size of an object appears different for each eye or that colors don't look the same for each eye.  These changes in eyesight are important symptoms and anyone who has these symptoms should make sure to see their eye doctor promptly.  Do not assume that you simply need a new pair of glasses and wait for an appointment in the future. 

___________________________________________________________

What is the Doctor Looking  For when he examines someone's eyes for macular degeneration?

There are two main forms of macular degeneration:  a dry form and a wet form.  There is another form, which is uncommon, called pigment epithelial detachment (PED).  In order to determine if you have macular degeneration and what form, the doctor will measure your vision and examine your eyes.  By looking at the retina, the doctor will be able to tell if there is an abnormality.  If drusen are found, you will want to schedule regular check-ups to make sure that no further changes occur.  It may be necessary that photographs of each macula be taken to use for comparison with future examinations.

Dry or Atrophic Macular Degeneration

 

 

Drusen are considered to be a dry form of macular degeneration.  When drusen are present for a long time, the macula may thin and stop working.  This is referred to as dry or atrophic macular degeneration and it often causes a slow and progressive loss of vision.  Some people with the dry form of macular degeneration notice blank areas in their central vision.  At this time there is no medical or surgical treatment for this form of macular degeneration; however, if both eyes are affected, eyesight may be helped somewhat with the use of special low vision lenses:  magnifying lenses for close-up and telescopic lenses for distance.  With counseling, people can learn to use some of their peripheral vision to help them see more clearly, and to cope more effectively with the practical tasks of every day life.  Because the dry form of macular degeneration with drusen or atrophy can change into the wet form, it is important for anyone with the dry form to monitor their central vision (with the Amsler grid, for example) and report any new changes to their eye doctor.

Although the dry form of macular degeneration with atrophy can cause a large loss of detail vision, the damage done by atrophy is generally not as great as the damage that can be caused by the wet form.  The dry form occurs in approximately 85 to 90% of people with advanced macular degeneration.  The wet form, which can be even more severe, occurs in only about 10 to 15% of people with advanced macular degeneration.

Wet Macular Degeneration (Choroidal Neovascularization- CNV)

In the wet form of macular degeneration, abnormal blood vessels grow under the retina and lift the retina up, very much like the roots of a tree growing under a sidewalk.  These abnormal blood vessels are called choroidal neovascularization, or CNV, because they grow from the choroid, the blood vessel layer under the retina.  The CNV (abnormal blood vessels) may leak fluid, bleed, and lift up the retina.  When this happens, central vision is reduced and is often distorted. 

The longer the CNV continues to leak, bleed, and grow, the more central vision (for detail) will be lost.  An eye with the wet form of macular degeneration will usually lose its ability to see detail.  In some cases, laser treatment done promptly may stop or minimize loss of vision but laser treatment does not guarantee that vision won't be lost.  In addition, if the CNV occurs in one eye, there is an increased chance that it will occur in the other eye.

The earlier that CNV is discovered, the more likely that some or much of the central (detail) vision can be saved.  The later CNV is discovered, the less likely laser treatment can be done.  Therefore, pay close attention to your eyesight and see your eye doctor immediately if there is any type of change in your vision.

Pigment Epithelial Detachment (PED)

In this uncommon form of macular degeneration a blister, a PED, can form in the macula, causing blurring or distortion of vision.  In a person over 50 years of age, the presence of a PED is considered a form of "wet" macular degeneration.  Laser treatment may be recommended if CNV (abnormal blood vessels) can be identified.  If you have a PED, you will want to have your eyes examined regularly to see if treatable CNV develops.

If you would like to schedule an appointment with Dr. Walt Bogart or if you would like more information regarding Macular Degeneration, please call our office at:  803-794-0000.