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) that will be discussed later. 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 damage is occurring.
It may be necessary that photographs of each macula be taken to use for
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 atrophy or atrophic macular degeneration and it often
causes a slow and progressive loss of vision.
Although there is no medical or surgical treatment for this form of macular
degeneration, eyesight may be helped somewhat with the use of special low vision
lenses: Magnifying lenses for close-up and telescopic lenses for distance. With
counselling, 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
change into the wet form, it is important for anyone with the dry form to monitor
vision (with the amsler grid, for example) and report any new changes to their
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 macular degeneration.
The wet form, which can be even more severe, occurs in only about 10% of
people with macular degeneration.
Wet Macular Degeneration
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
subretinal neovascularization, or SRNV. The abnormal blood vessels
located under the retina may leak fluid, bleed, and lift up the retina.
When this happens, vision is reduced.
The longer the abnormal blood vessels continue to leak, bleed, and grow,
the more detail vision 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 abnormal blood vessels occur in one eye, there is
about a one in ten chance per year that they will occur in the other
The earlier that abnormal blood vessels are discovered, the more likely
that some or much of the central (detail) vision can be saved. The
later abnormal vessels are discovered, the less likely laser treatment
can be done. In other words, pay close attention to your eyesight and
see your eye doctor promptly if there is any type of change in your
Pigment Epithelial Detachment (PED)
There is a third form of macular degeneration that is called pigment
epithelial detachment (PED). In this form of macular degeneration a
blister (a PED) can form in the macula, causing blurring or distortion of
vision. A PED occurs in less than 5% of people with macular
degeneration. Laser treatment is not usually recommended unless
abnormal blood vessels are also present. If you have a PED, you will
want to have your eyes examined regularly to see that the condition does