Angle-Closure Glaucoma

What is closed-angle glaucoma?

Angle-closure glaucoma is one of the two main types of glaucoma. Glaucoma is an eye disease in which the optic nerve is damaged. Sometimes this is because of high pressure inside the eye.

The "angle" refers to the corner between the iris (colored part of the eye) and the cornea (clear dome in front of the iris). It is in this angle where fluid drains from the eye. In angle-closure glaucoma, the iris comes forward towards the cornea and blocks the angle, not allowing fluid to go out of the eye. This can cause a pressure build up, which in turn can damage the optic nerve and vision loss. If this happens suddenly (acute angle closure), you will have severe pain, nausea, and vomiting.

How does it occur?

Normally, fluid in the eye is made by structures behind the iris called the ciliary processes. The fluid flows through the pupil and exits the eye through the angle. The lens sits behind the iris and the fluid must flow between the iris and the lens. When the angle is blocked or narrowed, fluid can't flow through very well. This can happen if the pupil is dilated too much causing the iris to "bunch up" or if the lens is too big and blocks the pupil. This is most common in people with:

• small, farsighted eyes
• a cataract that is expanding
• scarring inside the eye from inflammation.

In these susceptible eyes, dilation of the pupil can set off an attack. Your pupils can become dilated:

• in dim light
• after use of eyedrops given during an eye exam
• with use of some prescription medicines (some pills or shots) as well as some over-the-counter medicines.

What are the symptoms?

Symptoms of a sudden acute angle-closure attack may include:

• severe pain in and above your eye
• hazy or foggy vision
• halos around lights
• headache
• redness and watering of the eye
• nausea and vomiting.

When angle-closure glaucoma happens gradually there may not be any symptoms.

How is it diagnosed?

If the angle is suddenly and completely blocked, it is called an acute glaucoma attack and is a medical emergency.

Your doctor may look for:

• high eye pressure
• an iris that is pushed closer to the cornea
• a narrow or closed angle.

Your eye doctor may use the following tests:

• tonometry, a painless procedure used to measure the pressure in your eyes
• gonioscopy, which is a method of examining the drainage network in the angle between the iris and the cornea.

How is it treated?

If you are having an attack, your doctor may give you any of several medicines right away, such as:

• a mixture of glycerin and water to drink
• eyedrops that reduce the pressure in your eye quickly
• eyedrops that reduce the size of your pupil if it is dilated
• in severe cases, intravenous (IV) medicines to reduce the pressure in your eye.

Usually you will need laser treatment or surgery later to prevent more attacks. These procedures allow fluids to drain out of the eye. They may cure the problem permanently. Your doctor may recommend that you have both eyes treated if they both have narrow or closed angles, even though you may have had an attack in only one eye.

If you have never had an attack but appear to be at high risk, your doctor may recommend treatment to prevent an attack.

How can I take care of myself?

Make sure you have routine eye exams, especially after age 40.

If a routine eye exam shows that you have narrow angles, watch for symptoms such as eye pain, halos around lights, and nausea and vomiting. If you have these symptoms, tell your health care provider right away. The nausea and vomiting may lead your provider to suspect a problem in your digestive system. Be sure to tell your provider that you also have severe eye or forehead pain.