Glaucoma: Causes, Symptoms, Who Is at Risk and Treatment

What glaucoma is

Glaucoma is a group of diseases that can damage the optic nerve of one or both eyes, which can lead to vision loss. The most common type is open-angle glaucoma; less common types include angle-closure glaucoma and congenital glaucoma.

You may have no symptoms. Regular eye exams by an eye care provider can find glaucoma and other eye problems and help protect your vision. Treatment that lowers eye pressure helps slow the disease; without treatment, glaucoma can eventually cause blindness.

What causes it

Experts are not sure what causes glaucoma. The most common types usually happen when fluid pressure inside the eye slowly rises and damages the optic nerve. Other types can be caused by medical conditions, and a baby can be born with glaucoma.

High eye pressure does not always mean glaucoma, and some people get glaucoma with normal eye pressure: how much pressure an optic nerve can take differs from person to person. Regular dilated eye exams help your provider work out what level of pressure is normal for you.

Symptoms

Often there are none at first, or they come on so slowly you may not notice. Without treatment you slowly lose side (peripheral) vision, so it can feel like looking through a tunnel. Over time, straight-ahead vision may fade until no vision remains.

Go to your eye care provider or an emergency room right away if you suddenly have intense eye pain, blurry vision, red eyes or nausea. These can be signs of angle-closure glaucoma, a less common type in which fluid builds up quickly in the eye.

Diagnosis

A comprehensive eye exam can show whether you have glaucoma. It includes:

• A dilated eye exam. Drops widen your pupils to let in more light, and your provider looks through a special magnifying lens at the tissues at the back of your eye. Your vision may be blurry and sensitive to light for a few hours, so you will need someone to take you home.
• Visual field testing, which checks how well you see things off to the side without moving your eyes.
• Tonometry, which measures the pressure inside your eye.

Who is at higher risk

If you are at higher risk, get a comprehensive eye exam every one to two years. You are at higher risk if you:

• are Black or African American and over 40;
• are over 60, especially if you are Hispanic or Latino;
• have a family history of glaucoma.

If you have high blood pressure or diabetes, you are also at higher risk and should have a dilated eye exam at least once a year. Ask your provider how often you should have your eyes checked.

Treatment

There is no cure, but glaucoma can usually be controlled, and early treatment helps protect against vision loss.

• Prescription eye drops are the most common treatment, lowering eye pressure to protect the optic nerve.
• Other options are oral medicines, laser treatment and surgery.
• A combination may be used to lower pressure and help fluid drain from the eye.

Prevention

There is no way to prevent glaucoma. Eye exams can find it before it affects your vision, and if you have it, keep up your treatment so your vision does not get worse.

Sources

Based on "Glaucoma," MedlinePlus, National Library of Medicine, with its summary from the National Eye Institute, National Institutes of Health; a work of the United States government in the public domain.