Glaucoma is the name for a group of conditions that damage the optic nerve. The optic nerve carries messages from the eye to the brain and so damage to it can lead to a loss of vision.
Your eye requires a certain amount of pressure to keep the eye healthy and in the correct shape. This pressure is controlled by the amount of fluid within the eye. If there is a build-up of fluid in the front part of the eye this can lead to an abnormally high eye pressure. This abnormal high pressure causes damage to the optic nerve. Glaucoma is not always caused by high pressure and sometimes pressure can be apparently normal, but damage can still occur because the optic nerve is weaker and more susceptible to damage from pressure.
Glaucoma can be subdivided in to 2 major types
- Acute: Occurs suddenly and quickly
- Chronic: A gradual, slow progressing condition
The chronic type of glaucoma is more common than the acute type and the most common form of glaucoma is known as Primary Open Angle Glaucoma (POAG).
It is estimated that in the UK about 2% of people older than 40 have chronic open angle glaucoma, and for people older than 75 this rises to 10%, this equates to around half a million people in the UK. Around 60 million people worldwide are currently living with glaucoma, which makes it the second most common cause of blindness in the world. This number is expected to rise further with changes in population demographics.
As chronic glaucoma tends to develop slowly over many years and because it normally affects the peripheral vision first, it often doesn’t cause noticeable symptoms until damage has already occurred.
The less common acute glaucoma does cause symptoms such as a sudden onset of severe eye pain and blurred vision and it is important to act quickly, if you get these symptoms even if the symptoms appear to go away.
Glaucoma damage can be prevented if detected and treated early. However, damage to the optic nerve can’t be reversed and so sight loss is irreversible. If untreated, it can cause blindness. Glaucoma usually affects both eyes, although it may be worse in one eye.