Angle-Closure Glaucoma
What is angle-closure glaucoma?
Glaucoma is an eye disease in which the nerve that connects the eye to the brain (optic nerve) is damaged. Angle-closure glaucoma is one of the 2 main types of glaucoma. The other is called open-angle glaucoma.
The word angle in the term angle-closure refers to the corner between the iris (colored part of the eye) and the cornea (the clear outer layer on the front of the eye). This is where fluid drains from the eye. In angle-closure glaucoma, the iris has come forward towards the cornea, blocking the angle. The blockage prevents fluid from leaving the eye. This can cause a pressure buildup. The high pressure can damage the optic nerve and vision loss. If this happens suddenly (a problem called acute angle closure), it causes severe pain, nausea, and vomiting.
How does it occur?
Normally, fluid in the eye is made by parts of the eye behind the iris called the ciliary processes. The fluid exits the eye through the angle. 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, which is behind the iris, is too big and pushes the iris forward. In both cases, the iris will bow forward and close the angle. Crowding of the lens is most common in people with:
- small, farsighted eyes
- a cataract that is getting bigger
- scarring inside the eye from inflammation.
If you have any of the above problems, 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 the use of some medicines.
What are the symptoms?
If you have a sudden (acute) attack of angle-closure glaucoma, symptoms 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, you may not have any symptoms.
How is it diagnosed?
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 with a mirrored lens.
How is it treated?
An acute closed-angle glaucoma attack is a medical emergency. 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
- a pill called acetazolamide to reduce the pressure in your eye (you cannot take this pill if you are allergic to medicines containing sulfa)
- 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 just 1 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 of an attack. If you have eye pain or see halos around lights, along with nausea and vomiting, tell your healthcare 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.
