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Angle-closure Glaucoma

(Acute Angle-closure Glaucoma; Single Angle-closure Glaucoma)


Glaucoma is an eye disease that leads to damage of the eye nerve. Damage to the nerve can lead to poor or no vision. Angle-closure glaucoma (ACG) is one type of glaucoma. It may be:

  • Acute—sudden and severe rise in pressure
  • Chronic—gradual increase of pressure over time


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There are spaces between structures in the front of the eye. Fluid can drain out of the eye through these spaces. In ACG, these spaces shrink. Fluid can not pass out of the eye well. The extra fluid in the eye causes pressure in the eye to increase. Acute ACG may happen when structures of the eye slip and block these spaces. Chronic ACG may be caused by changes in the eye that happen slowly over time.

It is not clear why these changes happen. Some factors that play a role include:

  • Blood flow problems to the eye
  • Injury to the eye
  • Conditions that cause thickening of the lens of the eye

Areas of the eye can rub against each other with chronic glaucoma. This can cause damage to the drain. It will make it harder for fluid to drain well.

Medicine that may play a role include:

  • Adrenergics
  • Anticholinergics
  • Botulism injections around the eye
  • Sulfa-based drugs
  • Phenothiazines and monoamine oxidase inhibitors
  • Medicine to treat Parkinson disease

Risk Factors

ACG is more common in older adults. Other factors that may increase your chance of developing angle-closure glaucoma include:

  • Farsightedness
  • Family history of narrow angle glaucoma
  • Injury to the eye
  • Actions that cause sudden and fast widening of iris such as:
    • Eye drops used to dilate the eyes
    • Walking into dark room


There are few or no symptoms with chronic ACG. Acute ACG, also known as crisis may lead to:

  • Severe pain in the eye
  • Sudden vision loss
  • Blurred or cloudy vision
  • Halo around lights
  • Headache
  • Redness and swelling of the eye
  • Nausea
  • Vomiting

Acute ACG often happens in one eye at a time.

Chronic ACG may have had brief episodes of the symptoms above. The loss of space may happen in both eyes.


You will be asked about your symptoms and past health. A physical exam will be done. You will be referred to an eye specialist.

Tests may include:

  • Eye exam
  • Tonometry—to measure pressure in the eye
  • Slit-lamp examination—to check structures in the front of the eye
  • Gonioscopy—to check fluid channels of the eyes


Acute ACG will need immediate care. The pressure will need to be decreased to prevent nerve damage. Fast treatment can help to save vision.

Medicine can help to decrease pressure in the eye. It may be given as eye drops, pills, or through an IV.

Surgery can help to increase space in front of the eye. It is an option for chronic ACG or acute ACG once pressure is under control. Options include:

  • Laser peripheral iridotomy (LPI)—a hole is made in outer edge of the iris. It will increase open space for fluid to go.
  • Lens extraction—the lens of the eye is removed. It will increase space for fluid. However, it may only be used for people who also have cataracts.


ACG cannot be prevented.


The Glaucoma Foundation

Glaucoma Research Foundation


Glaucoma Research Society of Canada

The Canadian Ophthalmological Society


Angle-closure glaucoma. EBSCO DynaMed Plus website. Available at: Updated Ocotber 24, 2016. Accessed February 12, 2019.

Angle-Closure glaucoma. American Academy of Ophthalmology website. Available at: Updated December 18, 2013. Accessed February 12, 2019.

Angle-closure glaucoma. Glaucoma Research Foundation website. Available at: Updated January 14, 2015. Accessed February 12, 2019.

What is glaucoma? American Academy of Ophthalmology website. Available at: Updated April 15, 2018. Accessed February 12, 2019.

Last reviewed February 2019 by Daniel A. Ostrovsky, MD  Last Updated: 2/12/2019