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AGE RELATED
MACULAR DEGENERATION
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The Macula
Your eye is like a camera with a lens and an aperture (opening) at the front,
which both adjust to bring objects into focus on the retina at the back of your
eye. The retina is made up of a delicate tissue, sensitive to light - like film
in a camera. The very important is found at the centre of the retina and is
responsible for
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what we see straight in front of us
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the vision needed for such things as writing and
reading • our ability to appreciate colour
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WHAT IS MACULAR DEGENERATION?
Sometimes the delicate cells of the macula become damaged and stop working. It
is not known why, but it tends to happen as people get older - this is called
macular degeneration (MD). Because it is related to age, it usually
involves both eyes, but not necessarily at the same time. With many people, the
visual cells simply cease to work and colours fade as in old photos - this is
"dry" degeneration. Sometimes leaking blood vessels scar the macula - this is "disciform
maculopathy".
There is also an inherited form of macular degeneration called "macular
dystrophy". Possibly several members of a family will suffer from this and, if
your family is affected by this, regular eye checks are very important.
THE 'GOOD' NEWS
MD is not painful and never leads to total blindness because it is only the
central vision that is affected and it never affects the vision at the outer
edges of the eye, so almost everyone with MD will have enough side vision to get
around and keep their independence. It is the most common cause of poor
sight in the over 60s.
THE SYMPTOMS
Early signs, which can develop quickly or over several months, may be blurring
or distortion, with things seeming an unusual size or shape. There may also be
sensitivity to lights or actually seeing lights which are not there. This may
cause occasional discomfort. The macula allows you to see fine detail and, when
the condition is advanced, people may notice a blank patch or dark spot in the
centre of their sight - which makes reading, writing and recognising small
objects or faces very difficult.
WHAT SHOULD I DO IF I THINK I HAVE MD?
If you suspect you may have MD, you should see your doctor or optometrist
(optician) who will refer you to an eye specialist. If you have acute symptoms,
you should consult your doctor or local casualty department immediately. If you
already have MD in one eye and your other eye is getting acute symptoms, then
you should go to your usual hospital or local casualty department as soon as
possible.
WHAT DOES THE EXAMINATION INVOLVE?
Firstly, both your eyes will be assessed for vision. Then, to enable the
specialist to look into your eye, you will be given drops, which - while they
take about 20 minutes to take effect - blurring and sensitivity to light may
last for several hours, but is nothing to worry about.
WHAT IS "FLUORESCEIN ANGIOGRARHY”?
Sometimes, the specialist may decided that a "fluorescein angiogram" will also
be needed. A series of colour photographs of your retina, with bright flashes of
light, will be taken. These give an accurate map of the changes occurring in the
macula and enable the best treatment to be decided for you.
You will be given a small injection of special dye - in your arm - which works
its way to the eye. It is not painful, but you may feel a little sick. A series
of rapid pictures are then taken with a blue light. There are few side effects,
but people may find that they are dazzled for a while afterwards and may be left
with a faint yellow tinge from the dye, but this soon goes as urine is passed.
CAN I BE HELPED TO SEE BETTER?
With "disciform degeneration", laser treatment can help some people if it is
diagnosed early enough. There are also a variety of optical aids, such as
brighter reading lights, simple magnifying glass and more sophisticated
equipment, which make use of the parts of the retina which are not affected. Ask
to be referred to the hospital's low vision clinic.
WHAT DOES LASER TREATMENT INVOLVE?
Certain abnormalities with "disciform degeneration" can sometimes be treated by
laser. Treatment, which is not painful, but can cause some discomfort, is
usually carried in the outpatient department. You will be seated at a slit lamp
and a special contact lens is put into the eye to help focus the laser onto the
macula.
With most people, the areas of degeneration are in the middle of the macula - at
its focal point. In these cases, treatment canNOT be given as the scars produced
by the laser would make central vision worse rather than better.
Laser treatment is useful for about 10% of people with "disciform degeneration"
and this is always where early symptoms have been reported. If successful, it
can prevent things getting worse and sometimes bring back sight that is already
lost. "Dry" degeneration cannot be treated by laser.
TO FIND OUT MORE – contact:-
The
Macular Disease Society, P.O. Box 247, Haywards Heath, West
Sussex RH17 5FF
Produced by -
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INFORMATION ON EYE DISEASES LEAFLET #1.
(12/1999)
       
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