Angle-Closure Glaucoma

Angle-closure glaucoma happens because your enlarged iris blocks fluid from draining properly in your eye. This causes your intraocular pressure to rise. Acute (sudden-onset) angle-closure glaucoma causes eye pain, red eye and nausea. You need help immediately for this medical emergency.


Angle-closure glaucoma is when the iris and lens press together and cause pressure inside the eye to increase.
Angle-closure glaucoma is an emergency condition that happens when trapped fluid inside your eye causes pressure to build up.

What is angle-closure glaucoma?

Angle-closure glaucoma is one of two main types of glaucoma, a condition that’s defined by high pressure within your eye. The name for this pressure is intraocular pressure (IOP).

High IOP happens because fluid called aqueous humor can’t flow freely in your eye. In angle-closure glaucoma, a bulging or swollen iris (the colored part of your eye) blocks the drainage system. The condition may happen quickly or over time.

Other names for angle-closure glaucoma are closed-angle glaucoma and narrow-angle glaucoma.

Types of angle-closure glaucoma

There are different types of angle-closure glaucoma, including primary and secondary forms.

Primary angle-closure glaucoma

  • Acute angle-closure glaucoma comes on quickly and is a medical emergency because permanent vision damage can happen very quickly. Symptoms include severe eye pain, blurred vision, halos, nausea, vomiting and red eye.
  • Intermittent angle-closure glaucoma refers to cases where the drainage system changes from open to closed. You may or may not have symptoms.
  • Chronic angle-closure glaucoma may not cause symptoms at the beginning. But gradually, symptoms develop over time. Later, it might result in an episode of acute angle-closure glaucoma or a gradual increase of pressure with possible damage to your optic nerve.

Secondary angle-closure glaucoma

This form happens along with another condition. These include:

How common is it?

Angle-closure glaucoma will happen to about 1 in 1,000 people. It’s most likely to happen after the age of 40.

One estimate is that 17.14 million people throughout the world who are over 40 have primary angle-closure glaucoma, with a majority (12.3 million people) in Asia.


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Symptoms and Causes

What are the symptoms of angle-closure glaucoma?

Acute angle-closure glaucoma symptoms may include:

When they’re present, which doesn’t always happen, symptoms of chronic angle-closure glaucoma and other forms of non-acute angle-closure glaucoma may include:

What causes angle-closure glaucoma?

Angle-closure glaucoma happens because aqueous humor in your eye can’t flow in and out as it normally should. Your body constantly makes new fluid to replace the existing fluid.

When the old fluid can’t leave your eye, it backs up and causes pressure. The pressure causes damage to your optic nerve.

There are many reasons that you can get glaucoma. With angle-closure glaucoma, the reason is that your natural lens thickens over time and pushes against your iris, blocking the drainage passages.

Is it genetic/hereditary?

Research indicates that angle-closure glaucoma has an association with family history and certain genes.

What are the risk factors for angle-closure glaucoma?

Risk factors for developing angle-closure glaucoma include:

  • Age: The risk rises with age as IOP increases and your eye changes.
  • Sex: The risk is higher for women and people assigned female at birth (AFAB).
  • Ethnicity: The risk is higher for people of Asian descent.


What are the complications?

Like other forms of glaucoma, angle-closure glaucoma can damage your optic nerve and cause permanent loss of vision.

Diagnosis and Tests

How is angle-closure glaucoma diagnosed?

Any medical examination begins with your provider asking you questions about your symptoms and medical history, including information on your biological family’s history.

Your eye care provider will give you a thorough eye exam.

What tests will be done to diagnose this condition?

Your provider will diagnose angle-closure glaucoma using:

If your provider thinks you have angle-closure glaucoma, they’ll avoid using drugs that dilate your pupils because those medications could make drainage worse.


Management and Treatment

How is angle-closure glaucoma treated?

There’s no cure for angle-closure glaucoma, but there are treatments.

Treatments for acute angle-closure glaucoma

Treatment for acute angle-closure glaucoma must happen quickly to avoid vision loss.

Your provider will offer treatments that may include:

  • Medications. These include timolol, pilocarpine and brimonidine eye drops and oral acetazolamide.
  • Laser iridotomy. This is a procedure that makes a hole in your iris to allow fluid to flow freely. If you have an episode of acute angle-closure glaucoma in one eye, your provider will do an iridotomy on both eyes. Otherwise, you’re at risk of having an episode in your other eye.

Treatment for non-acute angle-closure glaucoma

Your provider is likely to treat non-acute forms of angle-closure glaucoma with laser iridotomy.

Your provider may also suggest cataract removal, which should make the progression of chronic angle-closure glaucoma go more slowly.

Complications/side effects of the treatments for angle-closure glaucoma

Complications may include blurred vision and sensitivity to light for a few days. You may also experience a streak of light from the site of the laser treatment. You typically need a driver to take you home after the procedure, but you may start normal activities the next day.


Can angle closure glaucoma be prevented?

No, you can’t prevent angle-closure glaucoma. But screening eye exams with an eye care provider will help you know if you have risks for angle closure glaucoma. They’ll then suggest treatment and medications to avoid if you’re at risk. It’s also very important to manage your blood sugar if you have diabetes.

Outlook / Prognosis

What can I expect if I have angle-closure glaucoma?

If you have treatment for angle-closure glaucoma, your outlook should be good. If you have acute angle-closure glaucoma, you need immediate treatment to preserve your vision.

You should listen to your provider’s suggestions on when and how often to return for eye exams.

Living With

When should I see my healthcare provider?

You should always see an eye care provider if you have changes in your vision. Follow the appointment schedule they suggest for you.

When should I go to an emergency room?

Times when you should get emergency medical help, like calling your eye care provider or going to an ER, include these events:

  • Symptoms that start up suddenly, like vision loss.
  • Severe eye pain.
  • A combination of symptoms, like red eye or nausea and eye pain.
  • An eye injury.
  • Symptoms that develop after any type of eye surgery.

What questions should I ask my doctor or eye care provider?

You may want to ask your healthcare team these questions:

  • What type of glaucoma do I have?
  • What treatment do you recommend?
  • Is the type of glaucoma I have hereditary?
  • What are the side effects of treatment?
  • What’s the outlook for my condition in the short term and the long term?
  • Are there activities that I should avoid?
  • How often should I schedule appointments?
  • Am I eligible to participate in a clinical trial?
  • Do you know of any support groups I could join?

It can help to take notes during your appointments. You may also want to bring a family member or friend to help you remember questions and answers.

A note from Cleveland Clinic

Glaucoma is common, and there are many types. Angle-closure glaucoma is one of these types. If you have an episode of acute angle-closure glaucoma, treat it as a medical emergency.

If you have eye pain, headaches, redness and you feel sick to your stomach, contact your provider or go to an emergency room. You may need immediate medical treatment to save your vision. Other types of angle-closure glaucoma also need treatment. It’s best to find out what you have and how to treat it early on in any condition.

Medically Reviewed

Last reviewed on 09/17/2023.

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