Angle-closure Glaucoma

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


Glaucoma is an eye disease that leads to damage of the eye nerve. This nerve is needed for vision. Damage can lead to poor or no vision.

Angle-closure glaucoma (ACG) is one type of glaucoma. It is the loss of space between the iris (color disc) and front, clear part of the eye. There is an area between these two that lets fluid drain out of the eye. When the space shrinks, it becomes harder for fluid to drain. This can lead to increased pressure in the eye and damage to the nerve. ACG may be:

  • Acute—sudden, severe blockage that cause rapid rise in pressure (iris slips down over drains)
  • Chronic—area shrinks slowly over time and leads to gradual increase of pressure


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Causes    TOP

It is not clear why this occurs. Some, factors that play a role include:

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

The iris and drains 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    TOP

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

Symptoms    TOP

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

Chronic ACG may have had brief episodes of symptoms above. The loss of space may happen in both eyes. However, a crisis often happens in one eye at a time.

Diagnosis    TOP

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 examine the front of the eye
  • Gonioscopy—to view channels of the eye

Treatment    TOP

Acute ACG will need immediate care. Pressure will need to be decreased to stop damage to the nerve. A severe loss of vision can occur if the pressure is not relieved.

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

Surgery can help to increase space in front of the iris. 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 to increase open space
  • Lens extraction—may be used for some people who also have cataract

Prevention    TOP

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: http://www.dynamed.... Updated Ocotber 24, 2016. Accessed August 31, 2018.
Angle-Closure glaucoma. American Academy of Ophthalmology website. Available at: Updated December 18, 2013. Accessed August 31, 2018.
Angle-closure glaucoma. Glaucoma Research Foundation website. Available at:
...(Click grey area to select URL)
Updated January 14, 2015. Accessed August 31, 2018.
What is glaucoma? American Academy of Ophthalmology website. Available at:
...(Click grey area to select URL)
Updated April 15, 2018. Accessed August 31, 2018.
Last reviewed June 2017 by Michael Woods, MD
Last Updated: 8/31/2018

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