Narrow angle glaucoma is an eye disorder that occurs when the eye drainage is blocked. It results in fluid build up behind the iris which increases the pressure inside the eye. Where the pressure builds up over time, it is known as chronic angle-closure glaucoma. When the internal eye pressure increases unexpectedly, it is known as acute angle-closure glaucoma. It is a real eye emergency and must be treated right away.

Narrow angle glaucoma is the less common of the two primary types of glaucoma. The patient’s eye angle may be tight from birth or may decrease with age among other reasons. If the drainage canal of the eye is narrow, fluid flow is reduced. When the eye drainage blocks slowly, fluid builds up over time. An unexpected blockage results in very rapid increase in the intraocular pressure. In this case, the patient must see an eye care professional immediately or suffer severe permanent eye damage.

Also Known As

Angle-closure glaucoma


There are two types of narrow angle glaucoma:

  • Chronic angle-closure glaucoma 
  • Acute angle-closure  glaucoma

Causes and Risk Factors

Some factors that can lead to narrow angle glaucoma include:

  • Severe diabetic eye disease
  • Defective eye structure
  • Eye trauma
  • Iris plateau
  • Blockage of the pupil
  • Hyperopia
  • Tumors 

Narrow angle glaucoma is more common in farsighted people because they have shorter eyes. A shorter eye may mean there is less room to accommodate the eye lens and the iris. 
Other risk factors include:

  • Age
  • Cataracts
  • Gender – Women are at a slightly higher risk.
  • Race – Eskimos and Asians are somewhat at higher risk.

Signs & Symptoms

Narrow angle glaucoma can be utterly asymptomatic unless a person develops acute angle-closure glaucoma. Symptoms include: 

Severe brow ache around the eye or head pain
Blurred or hazy vision
Halos around lights or appearance of rainbows around lights at night

  • Cloudy cornea
  • Dilated pupils 
  • Sudden vision loss
  • Red eye
  • Nausea  
  • Vomiting or stomach upset accompanied by eye pain

Acute angle-closure glaucoma needs urgent medical attention. If one notices any of these signs, they should go to a hospital emergency room or call a doctor immediately.


Narrow angle glaucoma can be detected using a variety of diagnostic tools. These help to measure eye pressure, check the optic nerve, and measure the eye angle to determine normality or abnormality.


Treatment is aimed at reducing the internal eye pressure or intraocular pressure as soon as possible.

Medical Treatment

Medical treatment can be done with systemic medications taken orally or sometimes applied intravenously. Topical eye drops can also be administered to lower the intraocular pressure as quickly as possible.

Surgical Treatment

Conventional or laser surgery can be used to unblock the eye drainage canals. This helps to drain the extra fluid and reduce the intraocular pressure.
Filtration surgery is used where conventional or laser surgery fails to reduce eye pressure long term. This procedure creates a new eye drainage canal to drain the fluid.

Prognosis/Long-term outlook

Narrow angle glaucoma can be a severe condition which appears suddenly. It can damage the optic nerve and cause permanent vision loss if not treated immediately. However, some chronic forms of the disorder progress very slowly and may cause eye damage without any pain or apparent symptoms in early stages.
Though narrow angle glaucoma can be severe, it is quite manageable with proper diagnosis and treatment.

Prevention/Follow Up

Anything that dilates the pupil can trigger acute angle-closure glaucoma. It results in the iris blocking the drainage angle in the eye's front chamber. Therefore, people at risk must be careful about darkness, dim lighting, stress, excitement, over the counter medications, and dilating eye drops.

Regular eye checkups are essential to condition diagnosis and proper eye health. One should begin to receive glaucoma evaluation from the age of 35. People above 60 and those at a higher risk of developing the condition should go for annual eye checks.