Glaucoma is an eye disease that causes damage to the optic nerve in your eye (the nerve that connects the eye to the brain). Pressure from fluid in your eye (intraocular pressure) can build up and this is what damages the optic nerve.
Image credit: Depositphotos
It’s sometimes called the ‘silent thief of sight’ because you can slowly lose your vision without being aware of it. That’s why it’s important to have regular eye health examinations by an eye health professional – an optometrist or ophthalmologist.
Glaucoma is one of the most common causes of preventable blindness in Aotearoa New Zealand and some types can be inherited (run in families). Glaucoma can’t be cured, but if it’s found early, treatment can stop it progressing and stop you from losing your sight.
There are different types. The most common type of glaucoma is chronic open-angle glaucoma. Acute angle closure glaucoma is an emergency as vision loss and blindness can occur quickly.
In the video below, glaucoma specialist Dr Divya Perumal talks about how glaucoma is diagnosed and managed.
Video: An introduction to glaucoma
(Glaucoma New Zealand, NZ, 2019)
How does glaucoma cause vision loss?
Fluid is produced in the front of your eye and this fluid produces pressure in your eye. Anything that slows or blocks the flow of this fluid will cause the pressure in the eye to increase and this pressure can eventually lead to optic nerve damage. The optic nerve is the ‘cable’ that connects your eye to your brain. It’s the nerve that sends images from your eye to your brain, so damage to this nerve causes loss of vision.
The damage to the optic nerve can’t be reversed so glaucoma must be found early to stop the damage getting worse.
For some people, damage to the optic nerve can occur when the eye pressure is in the normal range (normal tension glaucoma). In these cases, the damage is thought to be due to pressure sensitivity.