Closed Angle Glaucoma
Closed-angle glaucoma is a condition in which the pressure inside your eye becomes too high. There are a number of diseases that fall under the heading of glaucoma, with open-angle glaucoma being the most common; it accounts for around 90 percent of all cases. Closed-angle glaucoma is much less common. If they are not treated, all types of glaucoma have the potential to cause damage to your optic nerve, which is the nerve that transmits visual information to your brain.
If you have closed-angle glaucoma, pressure builds because fluid is not flowing out of your eye as it should. Fluid is produced in the rear chamber of your eye, behind the colored part, or iris. Normally, this fluid flows through your pupil, which is the black center of your eye, into the front chamber of the eyeball. From there, it goes through a series of channels called the trabecular meshwork and into the veins of the sclera (the white of your eye).
In closed-angle glaucoma, the trabecular network is obstructed or damaged and flow through this drainage pathway is reduced or blocked. The fluid backup then increases pressure within your eyeball.
Closed-angle glaucoma can be divided into two main types.
Primary Closed-Angle Glaucoma
In some people, the structure of the eye makes it more likely that the iris will become pressed against the trabecular meshwork. This could be because:
- The angle between the iris and cornea is very narrow.
- The eyeball is relatively short as measured from front to back.
- The lens inside the eye is thick.
- The iris is thin.
Secondary Closed-Angle Glaucoma
In this type of closed-angle glaucoma, an underlying condition causes changes in your eye that force the iris against the trabecular meshwork. These conditions may include:
- eye injury
- advanced cataract (clouding of the eye’s lens)
Whether it is primary or secondary, closed-angle glaucoma can also be described as acute or chronic. Acute cases are more common and occur suddenly. Chronic closed-angle glaucoma develops gradually, making the symptoms harder to spot.
Your risk for closed-angle glaucoma is greater if you:
- are older than 40 years of age, especially if you are between 60 and 70 years old
- are long-sighted
- are female
- have a brother, sister, or parent with the disease
- are of Southeast Asian or Eskimo origin
If you have the acute form of the condition, you will likely experience an “attack” or sudden onset of one or more of the following symptoms:
- severe eye pain that comes on suddenly
- blurred vision
- bright halos appearing around objects
- eye redness, tenderness, and hardness
- feeling nauseated and vomiting
The attack may occur when your pupils are moderately dilated—for example, when you are in a darkened room, when you are under stress, or after taking certain drugs.
If you do experience any of these symptoms, you should call your doctor right away, as acute closed-angle glaucoma is an emergency.
Symptoms of chronic closed-angle glaucoma are subtler. You may not notice any changes, or, if the condition progresses, you may realize that your sight is deteriorating and that you are losing the edges of your field of vision. Occasionally, some people experience eye pain and redness but not as severely as in acute closed-angle glaucoma.
Your doctor will ask questions about your condition, examine your eye, and measure your eye pressure. No special tests are needed. If treated urgently, your eye can recover. Acute cases of closed-angle glaucoma are emergencies, and your doctor will ensure that you are taken to the hospital as quickly as possible. When treatment is delayed, you could lose your sight.
Medication and surgery are used to treat closed-angle glaucoma.
You may need a number of different drugs including:
- acetazolamide, which reduces the fluid in your eye
- beta blockers, which lower the amount of fluid your eye produces
- steroids, which reduce inflammation
- drugs to treat nausea and vomiting
- pilocarpine, which opens the angle between your iris and cornea
Once the pressure in your eye has decreased, you will require further treatment to prevent it from rising again. There are two surgeries used to address closed-angle glaucoma:
This is a laser treatment that creates two tiny drainage holes in your iris. It is used to treat both acute and chronic closed-angle glaucoma.
In this less-common treatment, a surgeon makes a small triangular opening in your iris.
If you have a family history of glaucoma, you should have your eyes checked regularly. If you are at an especially high risk for closed-angle glaucoma, your doctor may recommend peripheral iridotomies to prevent an attack.
Written by: Helen Colledge and Marijane Leonard
Medically reviewed by George Krucik, MD