Glaucoma is the name for a group of eye diseases that damage the optic nerve.
The optic nerve, which carries information from the eye to the brain, is in the back of the eye. When the nerve is damaged, you can lose your vision.
Your risk for glaucoma rises after age 40 and even more quickly after age 70. Race is also a factor. African Americans are more likely than Caucasians to get the disease. You are also at risk if you have diabetes or if a close family member has had glaucoma.
At first, people with glaucoma lose side (peripheral) vision. But if the disease is not treated, vision loss may get worse. This can lead to total blindness over time.
There are three types of glaucoma.
- Open-angle glaucoma is the most common form in North America. In this type of glaucoma, the optic nerve is damaged bit by bit. This slowly leads to loss of eyesight. One eye may be affected more than the other. Sometimes much of your eyesight may be lost before you notice it.
- Closed-angle glaucoma is less common. About 10% of all glaucoma cases in North America are closed-angle. In this type of glaucoma, the coloured part of the eye (iris) and the lens block movement of fluid between the chambers of your eye. This causes pressure to build up and the iris to press on the drainage system of the eye. A related type is sudden (acute) closed-angle glaucoma. It is often an emergency. If you get this acute form, you will need medical care right away to prevent permanent damage to your eye.
- Congenital glaucoma is a rare form of glaucoma that some infants have at birth. Some children and young adults can also get a type of the disease.
Finding and treating glaucoma early is important to prevent blindness. If you are at high risk for the disease, be sure to get checked by an eye specialist (ophthalmologist) or optometrist even if you have no symptoms.
Damage to the optic nerve is often caused by increased pressure in the eye (intraocular pressure). This can happen when extra fluid builds up in the eye, such as when the eye makes too much fluid or does not drain well.
Some cases of glaucoma aren’t caused by increased pressure. In these cases, the cause may not be found.
You can get glaucoma after an eye injury, after eye surgery, or because of an eye tumour. Some medicines (corticosteroids) that are used to treat other diseases may cause glaucoma.
If you have open-angle glaucoma, the only symptom you are likely to notice is loss of vision. You may not notice this until it is serious. That’s because, at first, the eye that is not affected makes up for the loss. Side vision is often lost before central vision.
Symptoms of closed-angle glaucoma can be mild, with symptoms like blurred vision that last only for a short time. Severe signs of closed-angle glaucoma include longer-lasting episodes of blurred vision or pain in or around the eye. You may also see coloured halos around lights, have red eyes, or feel sick to your stomach and vomit.
In congenital glaucoma, signs can include watery eyes and sensitivity to light. Your baby may rub his or her eyes, squint, or keep the eyes closed much of the time.
See your doctor if you notice blind spots in your vision or if over time you are having more trouble seeing. It’s also a good idea to be checked for the disease if you have a family history of open-angle glaucoma, are over age 70, or have diabetes.
In adults, treatment can’t bring back vision that has been lost, but it can keep your vision from getting worse. Treatment aims to stop more damage to the optic nerve by lowering the pressure in the eyes.
Glaucoma is usually treated with medicine such as eyedrops. Be sure to follow a daily schedule for your eyedrops so that they work the way they should. You will likely need to take medicine for the rest of your life. You may also need laser treatment or surgery.
Learning that you have glaucoma can be hard, since much of your vision may be gone by the time it is detected. With counselling and training, you can find ways to keep your quality of life. You can use vision aids, such as large-print items and special video systems, to help you cope with reduced eyesight. You can also create a support group of people who can help with tough tasks.