What is a Narrow or Occludable Angle?

A narrow or occludable angle, also known as primary angle closure suspect (PACS), is a condition where the iris's positioning narrows or closes the eye's angle. This situation affects the flow of aqueous humor - a fluid produced by the ciliary body within the eye. Normally, this fluid circulates from the posterior chamber, passing through a gap between the iris and lens, to the anterior chamber. It then drains out via the trabecular meshwork, a tiny drainage system at the eye's angle, eventually being absorbed into the veins. Genetic factors and certain ethnic backgrounds, particularly in Asian populations, can influence the likelihood of developing this condition.


In many cases, narrow or occludable angles don't present immediate symptoms and are often first identified during an eye examination. However, it's crucial to be aware of any changes in vision or eye comfort.

Common Causes of Narrow or Occludable Angle

  • Age (typically over 40)
  • Family history of eye conditions
  • Higher prevalence in females
  • Non-age-related long-sightedness
  • Higher occurrence in certain ethnic groups, including Asians and Eskimos

Potential Complications

Individuals with this condition may experience acute angle closure glaucoma, characterized by sudden, high eye pressure leading to intense pain, redness, blurred vision, halos around lights, and even nausea or vomiting. Chronic angle closure glaucoma is another possible complication, where gradual pressure increase damages the optic nerve, often without early-stage symptoms.

Examination and Diagnosis

Ophthalmologists conduct a thorough examination of the anterior chamber and the angle between the cornea and iris using specialized lenses and equipment. This process is essential for accurate diagnosis and treatment planning and is a safe, non-invasive procedure.

Effective Treatments for Narrow or Occludable Angle

Treatment typically involves laser peripheral iridotomy, especially if the angle closure exceeds 180 degrees. This procedure is recommended even in asymptomatic cases to prevent the onset of primary angle closure glaucoma.

Preventive Measures

Regular check-ups with an ophthalmologist are crucial for early detection and prevention of primary angle closure glaucoma, particularly for those at higher risk due to age, family history, or ethnic background.