| Glaucoma |
|
|
| What
is glaucoma? |
Glaucoma
is the name for a group of eye conditions
at which the optic nerve is damaged at the
point where it leaves the eye. The nerve carries
information from the light sensitive layer
in your eye, the retina, to the brain where
it is perceived as a picture.Your eye needs
a certain amount of pressure to keep the eyeball
in shape so it can work properly. In some
people, the damage is caused by raised eye
pressure.
Others may have an eye pressure with in normal
limits but the damage occurs because there
is a weakness in the optic nerve. In most
cases both factors are involved but to a varying
extent. Eye pressure is largely independent
on blood pressure. |
| |
| Why
can increased eye pressure be serious? |
If
the optic nerve comes under too much pressure
then it can be injured, How much damage there
is will depend on how much pressure there
is and how long it has lasted. A really high
pressure will damage the optic nerve immediately.
A lower level of pressure can cause damage
more slowly, and then you would gradually
lose your sight if it were not treated. |
top
 |
| Are
there different types of glaucoma? |
There
are two main types.
Chronic glaucoma
The most common is chronic glaucoma (chronic
= slow) in which eye pressure rises very
slowly and there is no pain to show there
is a problem, but the field of vision gradually
becomes impaired.
Acute glaucoma
Acute glaucoma (acute = sudden) is much
less common in western countries. This happens
when there is a sudden rise in eye pressure.
This can be quite painful and will cause
permanent damage to your sight if not treated
promptly. |
| top
|
|
How common is glaucoma? |
| In
the UK some form of glaucoma affects about
2 in 100 people over 40. |
| top
|
| Are
some people particularly at risk of chronic
glaucoma? |
Yes,
there are several factors, which increase
the risk:
AGE: Chronic
glaucoma becomes much more common with increasing
age. It is uncommon below the age of 40 but
affects one percent of people over this age
and five percent of people over 65.
RACE: If you are of African
origin you are more at risk of chronic glaucoma
and it may come on somewhat earlier and more
severe.
FAMILY:
If you have a close relative that has chronic
glaucoma then you should have an eye test
every year. You should advise other members
of your family to do the same.
This is especially important if they aged
over 40. Please note: People over the age
of 40 years and with a family history of glaucoma-such
as parents, children, or siblings of people
diagnosed with glaucoma- are entitled to a
free sight test every two years under the
NHS. |
| |
|
How can chronic glaucoma
be serious risk to sight? |
| The early loss
in the field of vision is usually in the shape
of an arc a little above and/or below the
centre when looking ‘straight ahead’.
This blank area, if the glaucoma is untreated,
spreads both outwards and inwards. The centre
of the field is last affected so that eventually
it becomes like looking through a long tube,
so called ‘tunnel vision’. In
time even the sight would be lost. |
|
|
| How
is chronic glaucoma detected? |
- Viewing your optic nerve by shining
a light from a special electric torch
into your eye.
- Measuring the pressure in the eye using
a special instrument.
- Being shown a sequence of spots of
light on a screen and asked to say which
ones you can see. (Field of vision test)
All of these tests are straight forward
and are done as a matter of routine at
Opticare opticians.
|
|
|
|
How
is chronic glaucoma treated? |
The main treatment
for chronic glaucoma aims to reduce the pressure
in the eye. You will need to go to hospital
for treatment and have regular check-ups afterwards.
Treatment to lower pressure is usually started
with eye drops. If this does not help, your
specialist may suggest either laser treatment
or an operation called trabeculectomy to improve
the drainage of fluids from your eye. |
|
|
|
What
is acute glaucoma? |
In acute glaucoma
the pressure in the eye rises rapidly. This
is sometimes called closed angle glaucoma.
The sudden increase in eye pressure can be
very painful.
The affected eye becomes red,the sight deteriorates
and may even black out. There may also be
nausea and vomiting. In the early stages you
may see misty rainbow coloured rings around
white lights. Sometimes people have a serious
of mild attacks, often in the evening. Vision
may seem ‘misty’ with coloured
rings seen around white lights and there may
be some discomfort in the eye. |
|
|
|
Useful
What is the treatment? |
If you have an
acute attack you will need to go into hospital
immediately so that the pain and the pressure
in the eye can be relieved. Drugs will be
given to reduce the pressure.
When the pain and inflammation have gone down,
your surgeon will advise making a small hole
in the outer border of the iris to relieve
the obstruction, allowing the fluid to drain
away.
This is usually done by laser treatment or
by a small operation. Usually the surgeon
will also advise you to have the same treatment
on the other eye, because there is a high
risk that it will develop the same problem.
This treatment is not painful. |
|
|
|
Will
I be able to drive? |
| Most people can
still drive if the loss of visual field is
not to advances. To assess possible damage
to your peripheral vision you will a special
test to see whether your sight meets the standards
of the driver and Vehicle Licensing Authority.
This is available at Opticare Opticians (Newark
branch) |
|
|
|
What
if my sight cannot be fully restored? |
Early detection
and treatment will usually prevent or retard
further damage by glaucoma. Much can be done
to help you use your remaining vision as fully
as possible.
Ask us about low vision aids and whether you
are eligible to register as partially sighted
or blind. Registration opens the door to expert
help and sometimes to financial benefits.
|
|
|
