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 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. Congenital glaucoma is usually noticed when a child is only a few months old.

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.

One type of glaucoma, acute angle-closure glaucoma, is a medical emergency. You need treatment right away to save your vision.

Vision loss due to glaucoma cannot be recovered. It is 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 will generally need treatment for the rest of your life, which may include medications, surgeries, or other therapies.

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

Most people have no symptoms of early open-angle glaucoma. Few warning signs are noticed until permanent damage has already occurred. In some cases, open-angle glaucoma may cause:

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

Symptoms of acute angle-closure glaucoma may come and go at first, or steadily become worse. Acute angle-closure glaucoma may cause:

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

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.

Glaucoma is the result of damage to the optic nerve. As this nerve gradually deteriorates, blind spots develop in your visual field. 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 at the angle where the iris and cornea meet. When fluid is overproduced or the drainage system does not work properly, the fluid cannot 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.

To diagnose glaucoma, your doctor will review your medical history and conduct a comprehensive eye examination. This will include a test to check your eye pressure, which is called tonometry. In most examinations, you will be given eye drops to widen (dilate) your pupil. When your pupil is dilated, your eye doctor will look at the inside of your eye and the optic nerve.

You can take several steps to control high eye pressure and promote eye health:

• Eat a healthy diet. Eating a healthy diet can help you maintain your health, but it will not 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.

You cannot entirely prevent glaucoma. Most people have no symptoms, but you can help prevent or slow vision loss if you are at risk for glaucoma or have been diagnosed with the disease.

• A complete eye exam can help find open-angle glaucoma early, when it is easier to treat.
• All adults should have a complete eye exam by the age of 40.
• If you are at risk for glaucoma, you should have a complete eye exam sooner than age 40.
• You should have regular eye exams as recommended by your health care provider.
• If you are at risk for closed-angle glaucoma, your provider may recommend treatment before you have an attack to help prevent eye damage and vision loss.

The damage caused by glaucoma is not reversible, but treatment and regular checkups can help slow or prevent vision loss, especially if the disease is diagnosed in its early stage. The goal of glaucoma treatment is to lower pressure in your eye (intraocular pressure). Depending on your situation, your options may include eyedrops, laser treatment, or surgery.

Glaucoma treatment often starts with prescription eyedrops. These can help decrease eye pressure by improving how fluid drains from your eye or by decreasing the amount of fluid your eye makes.

Prescription eyedrop medications include:

• Prostaglandins, which increase the outflow of the fluid in your eye and reduce pressure in your eye. Examples include latanoprost (Xalatan) and bimatoprost (Lumigan).
• Beta blockers, which reduce the production of fluid in your eye, thereby lowering the pressure in your eye. Examples include timolol (Betimol, Timoptic) and betaxolol (Betoptic).
• Alpha-adrenergic agonists, which reduce the production of aqueous humor and increase outflow of the fluid in your eye. Examples include apraclonidine (Iopidine) and brimonidine (Alphagan).
• Miotic or cholinergic agents, which increase the outflow of fluid from your eye. An example is pilocarpine (Isopto Carpine).

If eyedrops alone do not decrease your eye pressure down to the desired level, your doctor may also prescribe an oral medication, usually a carbonic anhydrase inhibitor such as acetazolamide (Diamox) and methazolamide (Neptazane).

Other treatment options include laser therapy and various surgical procedures. Surgery and other procedures can help fluid escape from the eye and thereby reduce the pressure. However, these options is usually reserved for patients whose pressure cannot be controlled with eyedrops or pills.