What is glaucoma?
Glaucoma is the name of an eye condition in which the optic nerve is damaged at the point where it leaves the eye. The eye needs a certain amount of pressure to keep its shape so that it can work properly. In some people, the damage is caused by raised eye pressure. Others may have an eye pressure within normal limits but damage occurs because of a weakness in the optic nerve.
The most common form of glaucoma is chronic glaucoma where eye pressure rises very slowly but there is no pain to show there is a problem. If untreated, over a period of time, the field of vision gradually becomes impaired. Chronic glaucoma is more common with increasing age. It is uncommon below the age of 40, affecting 1% of people over this age and 5% over 65. If you have a close relative who has chronic glaucoma, then you should have regular eye tests. This is especially important if you are age over 40 when an annual test is recommended and funded by the NHS.
Acute glaucoma is much less common. This happens when there is a sudden rise in eye pressure. It can be quite painful and will cause permanent damage to your sight if not treated properly.
How is glaucoma detected?
Tests for chronic glaucoma are carried out as part of a regular eye test. Viewing the optic nerve by shining a light from an instrument into your eye, measuring the eye pressure using a special instrument called a tonometer and/or testing your fields of vision with a field screener which shows a flicker of light on a white background and meausures you ability/sensitivity to detect the flicker comparing it to an age matched sample of the population.
A sudden increase in eye pressure can be very painful. The affected eye becomes red and sight deteriorates. Vision may seem misty with coloured rings around white lights. There may even be nausea and vomiting.
How is glaucoma treated?
The main treatment for chronic glaucoma aims to reduce the eye pressure. It is usually achieved with eye drops but sometimes can involve a small operation to reduce the pressure. Immediate hospital treatment may be required with acute glaucoma.
Can glaucoma be cured?
Although damage already done cannot be repaired, with early diagnosis and treatment, damage can usually be kept to a minimum.
With thanks to the Royal College of Ophthalmologists and the IGA.