Open-Angle Glaucoma

What is open-angle glaucoma?

Open-angle glaucoma is the more common of the 2 main types of glaucoma in the US. Glaucoma is an eye disease in which the nerve that connects the eye to the brain (optic nerve) is damaged. Usually, high pressure inside the eye causes the damage. Sometimes, you can have glaucoma even though your eye pressure is normal.

Eye pressure builds up when fluid that normally flows out of the eye flows out too slowly. In open-angle glaucoma, the pressure increases slowly even though the drainage channel for the fluid is open. Without treatment, the eye pressure can damage the optic nerve and cause vision loss or blindness.

How does it occur?

Normally, the fluid in the front of the eye (called the aqueous humor) flows from a back chamber to a front chamber and then drains out. This fluid nourishes your eye and helps to keep its shape. It is not known what causes the fluid to drain out too slowly.

Open-angle glaucoma:

• occurs most often after age 55 but sometimes occurs in children
• tends to run in families
• is more common among black people than white people.

One type of open-angle glaucoma is caused by injury to the eye. It may show up months or years after the injury. This type of glaucoma may not respond to some common glaucoma medicines, and surgery may be needed.

Occasionally, nerve damage occurs without high pressure in the eye.

Using your eyes for close work or in poor light does not increase your chances of having glaucoma.

Open-angle glaucoma gets worse gradually if not treated. Usually it affects both eyes but sometimes only one eye is affected. You may not notice early vision loss caused by glaucoma. Blind spots occur first in side vision. Later, central vision may be affected. Vision loss is permanent because the damaged nerve cells cannot return to normal. However, treatment can prevent more damage and loss of vision.

What are the symptoms?

Open-angle glaucoma often causes no symptoms in the early stages. In later stages, you will begin to notice a loss of vision. Side vision is usually affected first.

How is it diagnosed?

Diagnosis is usually made during a routine eye exam.

• Your eye doctor can measure the pressure inside your eye with a quick and painless test.
• Your doctor checks the inside of your eye to see if there are changes in the optic nerve.
• Your doctor checks your side vision.

How is it treated?

The goal of treatment is to prevent more damage to the optic nerve by reducing pressure in the eye. This may be done with eyedrops, pills, laser surgery, or other surgery. Some of these treatments reduce the amount of fluid your eyes make. Other treatments increase the amount of fluid that leaves your eye or change the way the fluid flows.

For open-angle glaucoma, eyedrops may be the only treatment you need. Your eye doctor may want to check your eyes often to see if the medicine is working. The medicine may cause eye irritation, a rash, heart problems, or other side effects. Call your doctor if you have any side effects. Be sure to let all of your doctors know what eye drops you are using.

Laser treatments are common and often can lower pressure in the eyes. However, the procedure may need to be repeated.

You may need a surgical procedure called a trabeculectomy or another type of surgery called a tube shunt. In these procedures the eye surgeon creates a new pathway to drain fluid from the eye. These treatments are also called filtering surgery.

How can I help prevent open-angle glaucoma?

Open-angle glaucoma cannot be prevented. However, blindness can be prevented if you get treatment before pressure in the eye severely damages the optic nerve.

You may be able to help prevent open-angle glaucoma from becoming severe if you:

• Have regular, complete eye exams, according to your doctor's recommendation.
• Learn about your family history. Open-angle glaucoma often runs in families. Let your family members know if you have been diagnosed with glaucoma so that they may be checked.
• Take your eye drops as recommended. If it is hard for you to follow a recommended schedule, let your doctor know. Other treatments may be available.
• See your eye doctor right away if you notice any changes in your vision.