Overview

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 United States. 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.

Source: http://www.mayoclinic.com

Symptoms

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

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 percent of people with glaucoma become blind in at least one eye within 20 years.

When to see a doctor

Seek immediate medical care

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.

Schedule eye exams

Open-angle glaucoma gives few warning signs until permanent damage has already occurred. Regular eye exams are the key to detecting glaucoma early enough to successfully slow or prevent vision loss.

The American Academy of Ophthalmology recommends glaucoma screening:

• Every four years beginning at age 40 if you don't have any glaucoma risk factors
• Every two years if you're at high risk or over 65

Source: http://www.mayoclinic.com

Causes

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.

The types of glaucoma include the following:

Open-angle glaucoma

Open-angle glaucoma is the most common form of the disease. The drainage angle formed by the cornea and iris remains open, but the trabecular meshwork is partially blocked. This causes pressure in the eye to gradually increase. This pressure damages the optic nerve. It happens so slowly that you may lose vision before you're even aware of a problem.

Angle-closure glaucoma

Angle-closure glaucoma, also called closed-angle glaucoma, occurs when the iris bulges forward to narrow or block the drainage angle formed by the cornea and iris. As a result, fluid can't circulate through the eye and pressure increases. Some people have narrow drainage angles, putting them at increased risk of angle-closure glaucoma.

Angle-closure glaucoma may occur suddenly (acute angle-closure glaucoma) or gradually (chronic angle-closure glaucoma). Acute angle glaucoma is a medical emergency. It can be triggered by sudden dilation of your pupils.

Normal-tension glaucoma

In normal-tension glaucoma, your optic nerve becomes damaged even though your eye pressure is within the normal range. No one knows the exact reason for this. You may have a sensitive optic nerve, or you may have less blood being supplied to your optic nerve. This limited blood flow could be caused by atherosclerosis — the buildup of fatty deposits (plaques) in the arteries — or other conditions that impair circulation.

Glaucoma in children

It's possible for infants and children to have glaucoma. It may be present from birth or developed in the first few years of life. The optic nerve damage may be caused by drainage blockages or an underlying medical condition.

Pigmentary glaucoma

In pigmentary glaucoma, pigment granules from your iris build up in the drainage channels, slowing or blocking fluid exiting your eye. Activities such as jogging sometimes stir up the pigment granules, depositing them on the trabecular meshwork and causing intermittent pressure elevations.

Source: http://www.mayoclinic.com

Diagnosis

Your doctor will review your medical history and conduct a comprehensive eye examination. He or she may perform several tests, including:

• Measuring intraocular pressure (tonometry)
• Testing for optic nerve damage
• Checking for areas of vision loss (visual field test)
• Measuring corneal thickness (pachymetry)
• Inspecting the drainage angle (gonioscopy)

Source: http://www.mayoclinic.com

Prevention

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.

Alternative medicine

Some alternative medicine approaches may help your overall health but none are effective glaucoma remedies. Talk with your doctor about their possible benefits and risks.

• Herbal remedies. A number of herbal supplements, such as bilberry and ginkgo, have been advertised as glaucoma remedies. But further study is needed to prove their effectiveness. Don't use herbal supplements in place of proven therapies.
• Relaxation techniques. Stress may trigger an attack of acute angle-closure glaucoma. If you're at risk of this condition, find healthy ways to cope with stress. Meditation and other techniques may help.
• Marijuana. Research shows that marijuana lowers eye pressure in people with glaucoma, but only for three to four hours. Other, standard treatments are more effective. The American Academy of Ophthalmology doesn't recommend marijuana for treating glaucoma.

Source: http://www.mayoclinic.com

Lifestyle and home remedies

These tips may help you control high eye pressure or promote eye health.

• Eat a healthy diet. Eating a healthy diet can help you maintain your health, but it won't prevent glaucoma from worsening. Several vitamins and nutrients are important to eye health, including those found in dark, leafy greens and fish high in omega-3 fatty acids.
• Exercise safely. Regular exercise may reduce eye pressure in open-angle glaucoma. Talk to your doctor about an appropriate exercise program.
• Limit your caffeine. Drinking beverages with large amounts of caffeine may increase your eye pressure.
• Sip fluids frequently. Drink only moderate amounts of fluids at any given time during the course of a day. Drinking a quart or more of any liquid within a short time may temporarily increase eye pressure.
• Sleep with your head elevated. Using a wedge pillow that keeps your head slightly raised, about 20 degrees, has been shown to reduce intraocular eye pressure while you sleep.

• Take prescribed medicine. Using your eyedrops or other medications as prescribed can help you get the best possible result from your treatment. Be sure to use the drops exactly as prescribed. Otherwise, your optic nerve damage could get even worse.

  Because some of the eyedrops are absorbed into your bloodstream, you may experience some side effects unrelated to your eyes. To minimize this absorption, close your eyes for one to two minutes after putting the drops in. Or press lightly at the corner of your eye near your nose to close the tear duct for one or two minutes. Wipe off any unused drops from your eyelid.

Source: http://www.mayoclinic.com

Coping and support

When you receive a diagnosis of glaucoma, you're facing lifelong treatment, regular checkups and the possibility of progressive vision loss.

Meeting and talking with other people with glaucoma can be very helpful, and many support groups exist. Check with hospitals and eye care centers in your area to find local groups and meeting times. Several online resources, including support groups, are available.

Source: http://www.mayoclinic.com

Risk factors

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

Source: http://www.mayoclinic.com