Glaucoma is a group of eye conditions that damage the optic nerve,
the health of which is vital for good vision. This damage is often
caused by an abnormally high pressure in your eye.
Glaucoma is one of the leading causes of blindness for people over
the age of 60. It can occur at any age but is more common in older
adults.
Many forms of glaucoma have no warning signs. The effect is so
gradual that you may not notice a change in vision until the condition
is at an advanced stage.
Because vision loss due to glaucoma can't be recovered, it's
important to have regular eye exams that include measurements of your
eye pressure so a diagnosis can be made in its early stages and treated
appropriately. If glaucoma is recognized early, vision loss can be
slowed or prevented. If you have the condition, you'll generally need
treatment for the rest of your life.
Glaucoma is the result of damage to the optic nerve. As this nerve
gradually deteriorates, blind spots develop in your visual field. For
reasons that doctors don't fully understand, this nerve damage is
usually related to increased pressure in the eye.
Elevated eye pressure is due to a buildup of a fluid (aqueous humor)
that flows throughout the inside of your eye.
This internal fluid
normally drains out through a tissue called the trabecular meshwork at
the angle where the iris and cornea meet. When fluid is overproduced or
the drainage system doesn't work properly, the fluid can't flow out at
its normal rate and eye pressure increases.
Glaucoma tends to run in families. In some people, scientists have
identified genes related to high eye pressure and optic nerve damage
.
Types of glaucoma include:
Open-angle glaucoma
Open-angle glaucoma is the most common
form of the disease. The drainage angle formed by the cornea and iris
remains open, but the trabecular meshwork is partially blocked. This
causes pressure in the eye to gradually increase. This pressure damages
the optic nerve. It happens so slowly that you may lose vision before
you're even aware of a problem.
Angle-closure glaucoma
Angle-closure glaucoma,
also called closed-angle glaucoma, occurs when the iris bulges forward
to narrow or block the drainage angle formed by the cornea and iris. As a
result, fluid can't circulate through the eye and pressure increases.
Some people have narrow drainage angles, putting them at increased risk
of angle-closure glaucoma.
Angle-closure glaucoma may occur suddenly (acute angle-closure
glaucoma) or gradually (chronic angle-closure glaucoma). Acute
angle-closure glaucoma is a medical emergency.
Normal-tension glaucoma
In normal-tension
glaucoma, your optic nerve becomes damaged even though your eye pressure
is within the normal range. No one knows the exact reason for this. You
may have a sensitive optic nerve, or you may have less blood being
supplied to your optic nerve. This limited blood flow could be caused by
atherosclerosis — the buildup of fatty deposits (plaque) in the
arteries — or other conditions that impair circulation.
Glaucoma in children
It's possible for infants
and children to have glaucoma. It may be present from birth or develop
in the first few years of life. The optic nerve damage may be caused by
drainage blockages or an underlying medical condition.
Pigmentary glaucoma
In pigmentary glaucoma,
pigment granules from your iris build up in the drainage channels,
slowing or blocking fluid exiting your eye. Activities such as jogging
sometimes stir up the pigment granules, depositing them on the
trabecular meshwork and causing intermittent pressure elevations.
Various anaesthetic techniques are possible, including a general anaesthetic or a local anaesthetic that is injected around your eye to numb it.
The operation usually takes 45 to 75 minutes.
Your surgeon will make a small draining hole in the lining of the
white of your eye. The fluid will drain out into a space in the outer
lining of your eye and collect just under your eyelid
.
General complications of any operation:
Specific early complications:
Specific late complications:
You should be able to go home after a few hours.
Your surgeon will need to check your eye the day after the operation.
They will see you several times in clinic during the first few weeks
and may perform minor adjustments.
Most people will need about 2 weeks off work.
Do not swim, lift anything heavy or bend so your head is below your waist until you have checked with your surgeon.
Regular exercise should help you to return to normal activities as
soon as possible. Before you start exercising, ask the healthcare team
or your GP for advice.
Most people make a good recovery from the operation, with their glaucoma under better control.