Once detected, glaucoma can be treated to prevent or delay further vision damage.

What is glaucoma?

Glaucoma is the name of a group of conditions that damage the optic nerve that links the eye to the brain. Doctors don’t clearly understand why glaucoma happens.

The direct physical cause is that the optic nerve becomes damaged. This nerve carries signals from the back of your eye to the brain and allows you to see. Nerve damage often has something to do with the fluid in the eye.

Sometimes, the pressure of the fluid inside the eye rises, and the fluid presses hard on the optic nerve, damaging it. But glaucoma can also occur even when the fluid pressure in the eye is normal.

You are more likely to develop glaucoma as you get older. And you are slightly more likely to have glaucoma if a close relative has it. It is also more common in people of African or Asian descent than others.

Types of glaucoma

There are different types of glaucoma.

In primary open angle glaucoma, there is no obvious problem, but the fluid pressure builds up.

In angle closure glaucoma, the fluid stops circulating and the fluid pressure builds up quickly, causing pain in the eye and fairly sudden loss of vision.

Some people get normal pressure glaucoma, where the eye pressure hasn’t changed, but the optic nerve is still damaged.

Glaucoma may also arise after inflammation, injury or surgery to the eye. This is called secondary glaucoma.

Symptoms of glaucoma

People with angle closure glaucoma can get blurred vision, pain and a red eye, and might see haloes around bright lights. They can also feel nauseous, with headaches and vomiting.

Most people with glaucoma have few to no symptoms until their eyesight is damaged.

Prevention and diagnosis of glaucoma

Unfortunately, glaucoma can’t be prevented. But an optometrist or ophthalmologist can detect it early on if you have regular eye examinations every 2 to 3 years. They will look at the nerve fibres and the structure of the eye drainage network, test the field of vision and measure the eye pressure. This examination will take 20 to 45 minutes.

If you are of African or Asian descent, these regular examinations should start at age 40. Otherwise, you should start them at age 50.

You should be particularly careful about glaucoma if you:

• are short-sighted
• use cortisone (steroid) medications for long periods
• have diabetes
• have high or low blood pressure
• have migraine headaches.

Treatment of glaucoma

Nerve cells damaged by glaucoma can’t be repaired. Treatment is designed to prevent or slow further damage, mainly by reducing the pressure in the eye. This involves:

• eye drops or medicine
• laser surgery or other surgery to open or create a new drainage channel.

Glaucoma surgery is usually a day or outpatient procedure. You might have a local anaesthetic (such as eye drops) or a general anaesthetic. Your surgeon will explain to you the preferred type of surgery and anaesthetic for your condition.