What is Glaucoma?

Glaucoma is a group of conditions affecting the optical nerve, which links the eye to the brain and is vital for processing vision.

Glaucoma is caused by high pressure in the eye and weakness in the optical nerve. High pressure in the eye is unrelated to high blood pressure.

Pressure in the eye is usually balanced and plays an important part in the functioning of the eye.  This pressure is created when a fluid (known as aqueous) produced by cells behind the iris, passes through the pupil to be drained away by drainage tunnels in the angle of the eye (gap between the cornea and the iris). Pressure increases if the angle becomes blocked and the aqueous cannot drain away fast enough, or if too much aqueous is produced.


What types of Glaucoma are there?

There are two main types of glaucoma, chronic and acute; chronic means “slow onset” and acute means “sudden onset”.

Chronic glaucoma, also known as primary open angle glaucoma, is more common in Western countries than acute glaucoma and is easier to treat.  Chronic glaucoma causes no pain, and your eyesight feels normal, despite the damage being done to your optic nerve.

Many people who have had chronic glaucoma for a long time before diagnosis complain of one eye’s vision being worse than the others, or a loss of field vision in the shape of an arc above or below the centre of their vision.  If left untreated, it can result in “tunnel-vision”, and in time, this too is lost.

Acute glaucoma, also known as acute angle closure glaucoma, is characterised by sudden pain in the eye, as well as the appearance of misty rainbow coloured circles surrounding white lights. This may be followed by complete loss of sight and nausea and vomiting.

Usually, people experience a series of mild attacks in the evenings, and with routine inspection at the hospital or GP’s surgery, acute glaucoma is diagnosed.


How common is Glaucoma?

It is more common in people over the age of 40, and it affects 5% of the population over the age of 65.

It is most common in those aged above 70 but can affect people of all ages.

Those of African, Caribbean or Asian origin are more susceptible to glaucoma.

If a member of your family has had glaucoma, you are more likely to get it.


How can Glaucoma be treated?

Treatment includes eye drops (to reduce the amount of aqueous you produce, and to unblock the drainage tunnels) and laser surgery, to improve drainage.

Acute Glaucoma is initially treated with drops to reduce the amount of aqueous produced, followed by a small surgery. A small hole is made in the iris to remove the blockage in the angle of the eye.

It is recommended that this is done to both eyes, as if you suffer with acute glaucoma in one eye, it is highly likely that you will contract it in the other.

It is important to attend your optician appointments, because even if you feel as though your eyesight is fine, there may be damage to your optic nerve, which will reduce your quality of vision in the long run.

Many do not realise they have chronic glaucoma, and it is often picked up during a routine eye test.