Glaucoma

Glaucoma is a group of eye conditions that damage the optic nerve, which is vital to good vision. This damage is often caused by an abnormally high pressure in your eye.

Glaucoma is one of the leading causes of blindness in the U.S. It can occur at any age but is more common in older adults.

The most common form of glaucoma has no warning signs. The effect is so gradual that you may not notice a change in vision until the condition is at an advanced stage.

Vision loss due to glaucoma can't be recovered. So it's important to have regular eye exams that include measurements of your eye pressure. If glaucoma is recognized early, vision loss can be slowed or prevented. If you have the condition, you'll generally need treatment for the rest of your life.

Symptoms of glaucoma

The signs and symptoms of glaucoma vary depending on the type and stage of your condition:

Open-angle glaucoma:

• Patchy blind spots in your side (peripheral) or central vision, frequently in both eyes
• Tunnel vision in the advanced stages

Acute angle-closure glaucoma:

• Severe headache
• Eye pain
• Nausea and vomiting
• Blurred vision
• Halos around lights
• Eye redness

If left untreated, glaucoma will eventually cause blindness. Even with treatment, about 15% of people with glaucoma become blind in at least one eye within 20 years.

Promptly go to an emergency room or an eye doctor's (ophthalmologist's) office if you experience some of the symptoms of acute angle-closure glaucoma, such as severe headache, eye pain and blurred vision.

Causes of glaucoma

Glaucoma is the result of damage to the optic nerve. As this nerve gradually deteriorates, blind spots develop in your visual field. For reasons that doctors don't fully understand, this nerve damage is usually related to increased pressure in the eye.

Elevated eye pressure is due to a buildup of a fluid (aqueous humor) that flows throughout your eye. This fluid normally drains into the front of the eye (anterior chamber) through tissue (trabecular meshwork) at the angle where the iris and cornea meet. When fluid is overproduced or the drainage system doesn't work properly, the fluid can't flow out at its normal rate and pressure builds up.

Glaucoma tends to run in families. In some people, scientists have identified genes related to high eye pressure and optic nerve damage.

Risk factors for glaucoma

Because chronic forms of glaucoma can destroy vision before any signs or symptoms are apparent, be aware of these risk factors:

• Having high internal eye pressure (intraocular pressure)
• Being over age 60
• Being black or Hispanic
• Having a family history of the condition
• Having certain medical conditions, such as diabetes, heart disease, high blood pressure and sickle cell anemia
• Having certain eye conditions, such as nearsightedness
• Having had an eye injury or certain types of eye surgery
• Early estrogen deficiency, such as can occur after removal of both ovaries (bilateral oophorectomy) before age 43
• Taking corticosteroid medications, especially eyedrops, for a long time

Prevention of glaucoma

You may not be able to prevent glaucoma. But these self-care steps can help you detect it early, limit vision loss or slow its progress:

• Get regular eye care.
  Regular comprehensive eye exams can help detect glaucoma in its early stages before irreversible damage occurs. As a general rule, have comprehensive eye exams every four years beginning at age 40 and every two years from age 65. You may need more frequent screening if you're at high risk of glaucoma. Ask your doctor to recommend the right screening schedule for you.
• Know your family's eye health history.
  Glaucoma tends to run in families. If you're at increased risk, you may need more frequent screening.
• Exercise safely.
  Regular, moderate exercise may help prevent glaucoma by reducing eye pressure. Talk with your doctor about an appropriate exercise program.
• Take prescribed eyedrops regularly.
  Glaucoma eyedrops can significantly reduce the risk that high eye pressure will progress to glaucoma. To be effective, eyedrops prescribed by your doctor need to be used regularly even if you have no symptoms.
• Wear eye protection.
  Serious eye injuries can lead to glaucoma. Wear eye protection when using power tools or playing high-speed racket sports on enclosed courts.