Glaucoma is the name given to the condition that occurs when the pressure within the eyeball gets too high. There are several different causes for glaucoma, but they need to be treated because if left alone, the increased pressure within the eye can lead to problems with the blood supply and cause loss of sight. Untreated glaucoma is one of the leading causes of blindness around the world.

The eye contains lots of fluid. This fluid helps to maintain the shape of the eye. The fluid is constantly being secreted by an area behind the iris – the coloured part of the eye. The fluid then circulates around the eye before being drained away by a series of tiny channels. If there is a disruption in the drainage system, then the amount of fluid keeps going up and the pressure within the eye rises.

There are two main sorts of glaucoma. The first is known as open angle glaucoma, where these tiny channels slowly become blocked. This is a fairly gradual process that is often without symptoms. It may only come to light at a routine eye check or when visual loss is quite advanced. The second type is angle closure glaucoma where the fluid cannot pass through the pupil – the black part of the eye in the middle. This occurs much more swiftly and can be quite painful. The eye may become red with ‘halos’ around lights.

Other causes include infections or inflammation in the eye, or eye injury. Other conditions, such as poorly controlled diabetes can also lead to glaucoma. It is important that if your optician has diagnosed glaucoma that you are seen by an eye specialist in the hospital.

There are several treatments available for glaucoma, usually in the form of eye drops. Very occasionally tablets, laser treatment, or surgery may be needed. All of these methods are designed to reduce the pressure within the eye. Because of the need for rapid pressure reduction, eye drops may not be used as often in acute angle closure glaucoma.