• What is glaucoma?
• What are the symptoms?
• What causes it?
• Can it be treated?
• How can I avoid losing vision to glaucoma?
• Where can I get more help or information?

What is glaucoma?

Glaucoma is a group of eye diseases, which cause pressure to build up inside your eye and result in damage to the optic nerve.

The most common form of glaucoma is called open angle glaucoma. Normally, the area in front of the eye, called the anterior chamber, is filled with a fluid called aqueous. This fluid is made by a part of the eye called the ciliary body, and nourishes the inside of the eye before exiting through the eye’s drainage canals.

With glaucoma, the exit canals can become blocked over time, resulting in the aqueous being unable to drain from the eye. This causes a build-up of pressure, called intra-ocular pressure, in the eye. A good way to think of it is thinking of your eye as being like a balloon. If a balloon is filled with too much air or fluid, it will eventually pop, but the eye is too strong to pop. Instead, the eye swells, placing pressure on the optic nerve, which carries the information from the eye to the brain. This pressure on the tiny nerve endings in the optic nerve can eventually cause them to die, resulting in permanent loss of vision.

Another less common form of glaucoma is closed angle or acute glaucoma. This is where the drainage angle is too narrow and becomes blocked completely, like a clog in a sink. This form of glaucoma can cause severe and very sudden loss of vision.

What are the symptoms?

Glaucoma is called ‘the sneak thief of sight’ for very good reason. Most people with open angle glaucoma have no symptoms until they have already lost a significant amount of vision.

What causes it?

Glaucoma runs in families, so if someone in your family has had glaucoma, it is very important to get your eyes checked regularly.

Age is also a factor, and the risk of getting glaucoma increases as you get older. This risk is even higher if you have a family history of glaucoma.

Can it be treated?

Glaucoma can be treated with medication, either in the form of eye drops or pills, which lower the pressure inside the eye and help it to drain more efficiently.

Sometimes, eye surgery is performed either as well as or instead of medication, to widen the angle through which the aqueous fluid passes in order to help the eye to drain itself.

Vision loss caused by glaucoma, however, cannot be reversed, which is why regular eye tests for early detection are so important.

How can I avoid losing vision to glaucoma?

Get your eyes tested regularly, particularly if you:

• Are over 40
• Have a family history of glaucoma
• Have diabetes – people who have diabetes are almost twice as likely to develop glaucoma as non-diabetics

Where can I get more help or information?

You can find more information about glaucoma by visiting www.glaucoma.org.nz

The Royal New Zealand Foundation of the Blind can be contacted on 0800 24 33 33 or email general