What is glaucoma?

Glaucoma refers to a group of eye diseases where there is damage to the tiny fibres in the optic nerve. The optic nerve takes messages about what we see from the eye to the brain. About 2% of Kiwis over the age of 40, and about 10 % of those over 70 years have glaucoma.

Some types of glaucoma have rapid onset with pain and sudden loss of vision. However, most people with early glaucoma notice no discomfort or change in vision. This is because damage to the nerve fibres occurs slowly over many years, and often peripheral vision is damaged first. Our brains are very good at filling in missing patches and combining the pictures from the two eyes. This means a person may not notice vision loss until the disease is advanced, with just a central area of tunnel vision remaining.

The good news about glaucoma is that for many cases, early detection leads to effective treatments, often with daily eye drops, or possibly laser or surgical treatments.

NZ guidelines recommend a glaucoma check up with your optometrist or ophthalmologist at age 45, and, if there are no symptoms or risk factors, the glaucoma eye check should be repeated every five years.

If vision has been lost due to glaucoma, that vison cannot be regained. Often people will have patches of vision missing above, and/or below the horizontal mid line. Central vision can also be damaged in later disease. People with glaucoma often notice that they have poor contrast sensitivity, this means that while they may be able to see black letters on a white background, they cannot pick out an item on a cluttered bench, or safely identify steps and kerbs.

Blind Low Vision NZ can help people to understand which part of their vision is not working well. This is especially helpful when they want to explain to family and friends what is going on. The specialists at Blind Low Vision NZ can help people to come to terms with their vision loss, and to learn to use new techniques or equipment to make the most of their remaining vision, so that they can continue to do the things that are important to them.
For more information, visit the Glaucoma NZ website.