What Is Angle Closure Glaucoma?

Published July 7, 2020

Angle closure glaucoma is a rare, but serious form of glaucoma that requires immediate medical attention.  

Closed angle glaucoma develops as a result of a sudden build up of eye pressure (intraocular pressure, IOP)— rising to a dangerous level in just a few hours.

  • Glaucoma affects up to 5% of adults ages 70 and above, and increases to over 9% for those 80 and older.
  • Angle closure glaucoma accounts for less than 20% of all glaucoma cases.
  • About 1 in 1,000 people develop angle closure glaucoma in their lifetime.
  • Angle closure glaucoma typically affects people over the age of 40, and most frequently occurs around age 60-70 years.

Symptoms of angle closure glaucoma

If you experience any of the following symptoms, seek immediate medical attention. 

  • Blurred vision
  • Seeing halos around lights
  • Eye pain
  • Headaches
  • Nausea
  • Vomiting

Why is it called ‘closed angle’ glaucoma?

Closed angle glaucoma occurs when your iris and cornea move toward each other, closing the anterior angle between them. When the angle is closed, it blocks the entire fluid drainage system, namely the uveoscleral drains and trabecular meshwork— blocking the outflow of ocular fluid completely.

This sudden halt of fluid drainage, causes a sudden increase in IOP to 30, 40, or even 50+ mm Hg, and damages the optic nerve.

It is important to seek immediate medical attention, to receive treatment as soon as possible— this is a medical emergency that can cause permanent blindness in a matter of hours. 

Who is at risk of angle closure glaucoma?

Closed angle glaucoma can occur when your pupils dilate too wide, or too quickly. The following factors may put you at a higher risk of angle closure glaucoma.

  • Age, over 55
  • Family history of glaucoma
  • Narrow anterior angle
  • Asian or Inuit descent
  • Gender, female
  • Diabetic retinopathy
  • Cataracts
  • Moderate to high farsightedness (hyperopia)
  • Ocular tumors
  • Ectopic lens, when lens moves within the eye
  • Ocular ischemia, narrowed blood vessels in the eye
  • Uveitis, or ocular inflammation
  • Certain drugs such as antihistamines, cold medications, and antidepressants
  • Medications such as sulfonamides, topiramate, or phenothiazines

      How is angle closure glaucoma treated?

      Angle closure glaucoma is generally treated with anti-glaucoma eye drops or surgery.

      Different types of eye drops or surgeries aimed at reducing IOP levels may be recommended, depending on the stage of glaucoma.

      Anti-glaucoma eye drops

      Anti-glaucoma eye drops are often the first plan of action, as most cases of glaucoma can be controlled with eye drops.

      Types of eye drops:

      • Prostaglandins relax the muscles in the eyes to allow better fluid drainage, reducing build-up of IOP.
      • Beta-blockers are used in a variety of glaucoma eye drops. They decrease the amount of ocular fluid production and are often prescribed in combination with prostaglandins.
      • Alpha-adrenergic agonists decrease the rate of fluid production. They can be used alone or in combination with other anti-glaucoma eye drops.
      • Carbonic anhydrase inhibitors decrease the rate of fluid production, and are used in combination with other anti-glaucoma eye drops
      • Parasympathomimetics are very often used to control IOP in narrow-angle glaucoma. They work to increase ocular fluid drainage by opening the narrow angle where drainage occurs.
      • Epinephrine decreases the rate of ocular fluid production, and increases its outflow from the eye.
      • Hyperosmotic agents are used in emergencies, for patients with a severely high IOP that must be reduced immediately before permanent damage occurs. They reduce IOP by lowering ocular fluid volume.
      • Combination glaucoma drugs include two different anti-glaucoma medicines. Many times, patients with glaucoma require more than one type of medication to control IOP.

      Iridotomy 

      Iridotomy is a laser procedure in which a tiny hole is created in the iris to release fluid build-up, and improve fluid drainage through the anterior angle.

      Trabeculectomy

      Trabeculectomy is a non-laser procedure that is performed in cases of advanced glaucoma, where severe IOP levels have caused optic nerve damage. During this procedure, the surgeon creates an artificial opening in the eye for ocular fluid to effectively drain through.

      Suprachoroidal shunts

      Suprachoroidal shunts successfully lower IOP levels, and can be effective in treating moderate to severe glaucoma. During this procedure, tiny tubes or shunts, are inserted into the eye to improve fluid drainage from the anterior angle.

      When to see your eye doctor

      Closed angle glaucoma is an acute condition that occurs suddenly, and requires immediate medical attention.

      If you are concerned about your vision and ocular health, or you may be at risk of developing angle closure glaucoma, schedule a comprehensive eye exam as soon as possible.

      Your eye doctor can detect signs of increased eye pressure before damage occurs, and prescribe an effective treatment to help prevent vision loss.