Glaucoma: Angle-Closure

What is angle-closure glaucoma?

Glaucoma is an eye disease that damages the nerve that carries visual messages to the brain (optic nerve). This is usually caused by high pressure inside the eye. Damage to the optic nerve can cause a permanent loss of vision. Glaucoma needs to be diagnosed and treated early to prevent blindness.

Normally, the fluid in the front of the eye is constantly flowing from where it is formed (the ciliary body) to the front of the eye. This fluid nourishes your eye and helps to keep its shape. The area between the iris (colored part of the eye) and the cornea (the clear outer layer on the front of the eye) is called the angle. Fluid drains out through the angle, into drainage channels, and is then reabsorbed by the body. When fluid flows out too slowly, eye pressure builds up.

In angle-closure glaucoma, the angle between the iris and the cornea is blocked or narrowed. When this happens, fluid is not able to drain from the eye. This can cause a pressure buildup. This can either happen slowly or suddenly. When it happens suddenly, it is called acute angle-closure glaucoma and is a medical emergency.

Angle-closure glaucoma is the second most common type of glaucoma.

What is the cause?

The angle between the iris and the cornea may be blocked or narrowed if the pupil is dilated too much, causing the iris to bunch up, or if the lens crowds the iris and causes it to bend forward and close the angle.

Your pupils can become dilated:

  • In dim light, such as a movie theater
  • After use of eyedrops given during an eye exam
  • With some medicines you take by mouth

Crowding of the lens is most common in people with:

  • Farsightedness (you see distant objects clearly, but close objects are blurry)
  • Diabetes
  • A cataract that is getting bigger
  • Scarring inside the eye from inflammation

If you have any of these problems, dilation of the pupil can make the problem worse, causing an acute angle-closure glaucoma attack.

What are the symptoms?

If you have a sudden (acute) attack of angle-closure glaucoma, symptoms may include:

  • Severe pain in and above your eye
  • Hazy or foggy vision
  • Halos around lights
  • Headache
  • Redness and watering of the eye
  • Nausea and vomiting

When angle-closure glaucoma happens gradually, you may not have any symptoms.

How is it diagnosed?

Your eye care provider may:

  • Measure the pressure in your eyes and the thickness of your cornea
  • Check for changes in your side vision caused by damage to the optic nerve
  • Look at the optic nerve inside your eye
  • Examine the drainage channels with a special mirrored lens
  • Look for an iris that is pushed closer to the cornea
  • Look for a narrow or closed angle

How is it treated?

An acute closed-angle glaucoma attack is a medical emergency. If you are having an attack, your provider may give you medicines to reduce eye pressure.

Usually, you will need laser treatment or surgery to treat the attack or to prevent more attacks. Laser treatment or surgery redirects fluid flow in the eye. Treatment helps prevent further vision loss. It does not make your vision better. If you also have cataracts, removing the cataracts may lower the pressure in your eyes. A cataract is a cloudy area in the lens of the eye. The lens is located inside your eye behind the iris.

The type of surgery you have depends on the type and severity of your glaucoma and other health problems you may have. You may need to have both eyes treated if they both have narrow or closed angles, even though you may have had an attack in just one eye.

If you have never had an attack but appear to be at high risk, your provider may recommend treatment to prevent an attack.

How can I take care of myself?

Make sure you have routine eye exams, especially after age 40.

If a routine eye exam shows that you have narrow angles, know the symptoms of an attack. If you have eye pain or see halos around lights, along with nausea and vomiting, tell your healthcare provider right away. Be sure to tell your provider if you have severe eye or forehead pain.

How can I help prevent glaucoma?

Glaucoma cannot be prevented. However, blindness can be prevented if glaucoma is treated before pressure in the eye has damaged the optic nerve too much.

You may be able to help prevent glaucoma from becoming severe if you:

  • Have regular eye exams that include measuring the pressure in your eye and examining your optic nerve and visual field. How often you need to see the eye care provider will depend on how severely your optic nerve is damaged.
  • Learn about your family history. Chronic open-angle glaucoma often runs in families.
  • See your healthcare provider right away if you see halos around lights or notice any changes in your vision.

Reviewed for medical accuracy by faculty at the Wilmer Eye Institute at Johns Hopkins. Web site:

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