Glaucoma is caused by a build up of pressure in the eye when it fails to maintain a balance between the amount of internal fluid that is produced and the amount that drains away. The eyeball needs the appropriate amount of pressure to maintain its shape but when this pressure increases to a dangerously high level it causes glaucoma.
The eye is unable to relieve this pressure and it keeps building and pushing against the optic nerve until nerve fibres are permanently damaged and vision is lost. There are different types of glaucoma including:
Open angle glaucoma; the most common form and it is typically seen in adults over the age of 40. The optic nerve is damaged to a gradual build up of pressure.
Low tension glaucoma; low pressure in the eye can cause optic nerve damage.
Angle closure glaucoma; a sudden increase in pressure inside the eye. Symptoms include redness of the eye, blurred vision, severe pain and nausea.
Congenital glaucoma; it is extremely rare but children can be born with glaucoma. A defect in the angle of the eye slows fluid drainage which results in increase of pressure. Surgery has a high success rate.
Secondary glaucoma; can be caused by complications from other medical conditions such as eye injuries, advanced cataracts, eye tumours and diabetes.