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Glaucoma.

Overview

What Is It?

Often called the "sneak thief of sight," glaucoma refers to a group of eye diseases that damage the nerves carrying images from the eye to the brain.

Often called the "sneak thief of sight," glaucoma refers to a group of eye diseases that damage the nerves carrying images from the eye to the brain. It is a leading cause of blindness in the United States, accounting for 9 to 12 percent of all blindness, according to the Glaucoma Research Foundation. The organization estimates that over four million Americans have the disease, but half don't know it. Glaucoma usually produces no symptoms until the disease has progressed to the point of robbing a person's sight.

Although glaucoma has no cure, it can be controlled and vision maintained if it is caught early. That's why comprehensive eye examinations are recommended at least every two years for those at increased risk for the disease. Although anyone can get glaucoma, the risk is higher for those over age 60, those who have a family history of the condition, and African Americans. The National Eye Institute reports that African Americans are five times more likely than Caucasians to develop glaucoma. The risk of blindness from glaucoma is four times greater in African Americans than Caucasians overall, and 15 times greater in African Americans age 45 to 65 than in Caucasians of the same age, according to the institute.

Additional risk factors include:

* diabetes

* nearsightedness, called myopia

* regular, long-term steroid or cortisone use, particularly if they have been in the form of eyedrops

* previous eye injury

Another risk factor for glaucoma is high pressure within the eye. Pressure in the eye is known as intraocular pressure. It's a common misconception that having high intraocular pressure means you're a victim of glaucoma. In fact, you can have high intraocular pressure, known as ocular hypertension, and not have glaucoma. Whether you develop glaucoma depends on how much pressure your optic nerve-the bundle of 1.2 million nerve fibers that transmits images from the eye to the brain-can take without being damaged.

The first step in understanding glaucoma and its relationship to intraocular pressure is learning how the eye works. The outer protective layer of eye includes clear tissue through which light enters the eye, known as the cornea. The iris is the colored part of the eye that contains muscles that make the pupil (the dark-colored area in the center of the eye that lets light into the eye) open and close. Located behind the iris is the lens, a transparent structure with an outward curve on both sides that focuses light onto the retina at the back of the eye. The retina is made of light-sensitive tissue that sends visual messages via nerve impulses to the brain through the optic nerve. The brain then processes the nerve signals into the images you see.

The anterior chamber is a space in the eye bordered by the cornea, iris, pupil and lens. Flowing through this chamber is a liquid, called the aqueous humor, which supplies oxygen and nutrients to the cornea and lens and helps maintain the shape of the eyeball. A tiny gland, called the ciliary body, is located behind the iris and produces the fluid. The fluid travels from the gland through the pupil into the anterior chamber, exiting at an angle where the cornea and the iris meet. At the angle is a spongy mesh of tissue that works like a drain, called the trabecular meshwork.

There are several forms of glaucoma, including the following:

* Open-angle. In this most common form of glaucoma, the angle where the cornea and the iris meet is open, but the aqueous humor fluid passes too slowly through the meshwork drain. As a result, the pressure in the eye gradually increases, compressing cells in the optic nerve. If left untreated, the compression eventually will cause the optic nerve cells to die, producing blindness.

According to the Glaucoma Research Foundation, more than three million Americans have open-angle glaucoma. This type of glaucoma is the leading cause of blindness among African Americans, accounting for 19 percent of blindness in African Americans, compared to only 6 percent in Caucasians. Early detection is essential to managing open-angle glaucoma and minimizing vision loss. Treatments include medications in the form of eyedrops and pills to reduce the amount of aqueous humor in the eye or improve its drainage, both of which help reduce intraocular pressure. Surgery, either by using a laser or by conventional means, also may be recommended.

* Angle-closure. Angle-closure glaucoma occurs in two forms: acute and chronic. The acute version can be a sudden, painful attack requiring emergency treatment. The chronic version occurs over time, producing no recognizable symptoms before vision is lost.

People with angle-closure glaucoma tend to have a smaller-than-average anterior chamber, and the angle between the iris and the cornea where the aqueous humor drains is also smaller. When the lens naturally grows larger with advancing age, the aqueous humor has difficulty flowing in the tight space, causing the fluid to build up behind the iris, narrowing the angle even more. When the pupil dilates, such as when entering a dark room, or when experiencing anxiety or stress, the angle narrows even further, and the iris is forced against the trabecular meshwork, stopping drainage. Without drainage, pressure in the eye squeezes and damages the optic nerve.

In acute angle-closure glaucoma, intraocular pressure rises suddenly, producing pain. The eye turns red, the cornea swells and clouds, vision may be blurred and lights may appear as if they have halos. Treatment with eyedrops that help reduce the eye's production of aqueous humor and constrict the pupil may stop an acute attack. Surgery to improve the flow of the aqueous humor is usually recommended.

In chronic angle-closure glaucoma, the iris gradually closes over the drain, causing no recognizable symptoms. As this occurs, scars form between the iris and the drain, eventually blocking it and driving up intraocular pressure. Treatment may include eyedrops and surgery.

Although rare in women, a problem called pigment dispersion syndrome can cause angle-closure glaucoma. The syndrome occurs when grains of pigment on the back of the iris flake off into the aqueous humor, eventually clogging the drainage meshwork and raising eye pressure. The syndrome produces no noticeable symptoms, but can be detected and monitored in routine eye examinations. About 30 percent of patients with pigment dispersion syndrome develop pigmentary glaucoma, a type of open-angle glaucoma, according to the Glaucoma Research Foundation.

* Normal-tension. Some people with normal eye pressure develop glaucoma, a disease known as low-tension or normal-tension glaucoma (NTG). In this form of the disease, eye pressures are within the normal range, but the optic nerve progressively deteriorates. The progression of the disease is faster in those who have the specific risk factors for progression, namely, Japanese ancestry, cardiovascular disease, family history of any kind of glaucoma and female gender. Research is continuing on this form of glaucoma, which is thought to be related to poor blood flow to the optic nerve.

Diagnosis

No single test is 100 percent effective in determining whether you have glaucoma. To diagnose the disease, your health care professional will ask you questions about your medical history and conduct a comprehensive eye examination, which may include any of the following painless tests:

* Visual acuity. This test measures the ability of your central vision to distinguish details and shapes. You will be asked to cover an eye and read a chart to measure how well you see at various distances.

* Perimetry. This test, also called a visual field test, measures your side or peripheral vision. Today, it is often done with computerized equipment. You place your chin on a stand in front of a computerized screen. You are asked to focus on a spot on the screen and push a button or indicate when you see a flash of light. This gives your health care professional a "map" of your field of vision.

* Tonometry. This is a test to measure your intraocular pressure. It can be performed in a variety of ways. In applanation tonometry, you are given drops to numb your eye, and a pressure-sensitive tip is placed against the eye to measure its pressure. The eye is also numbed with drops in Schiotz tonometry, where a plunger-like device is applied to the eye, determining pressure by how far the device indents the eye. No instrument touches the eye in noncontact, or "air puff" tonometry, in which air is blown at the eye and pressure assessed by the eye's resistance to it.

* Ophthalmoscopy. In this test, your health care professional places drops in your eyes to widen, or dilate, your pupils, and looks through the pupil at the optic nerve using a special instrument for viewing the back of the eye called an ophthalmoscope. Your close vision may be blurred for several hours after this examination until the dilating drops wear off.

* Gonioscopy. In this test, a special lens containing a mirror is placed lightly on the front of the eye so the health care professional can visually examine the angle between the cornea and the iris inside the eye.

Treatment

Glaucoma treatments generally focus on reducing intraocular pressure to a level your health care professional believes will not cause further damage to the optic nerve. This level is often called the "target pressure," and it differs from person to person and may change over the course of treatment. Eye pressure is measured in millimeters of mercury (mm Hg) and it varies, even throughout the day. Generally, eye pressure readings between 10 and 20 mm Hg are considered normal, although a person may have glaucoma even with pressures in this range.

Most newly diagnosed cases of glaucomaare treated with medications, which come in topical and oral form. Topical medications may be eyedrops, inserts of thin wafers you place under your eyelid or in the corner of your eye, or eye ointments and gels. Oral glaucoma medications come in pill and tablet form.

The most common topical medications are eyedrops, and some of them must be taken several times a day. Most topical medications reduce eye pressure by either increasing the flow of the aqueous humor out of the eye or reducing the amount of the fluid produced in the eye. The following are types of topical glaucoma medications:

* Miotics. These drugs increase the rate at which the aqueous humor flows out of the eye. Pilocarpine is the most common and oldest miotic used to treat glaucoma. It comes in drop, gel and insert form. Dosage for the drops is typically one drop, one to four times a day. The gel formis usually taken once a day at bedtime. The insert is taken once every several days. Common brands of pilocarpine include Isopto Carpine, Ocusert, Pilocarpine and Pilopine. [If you have asthma or other kinds of eye diseases, tell your health care professional before taking this medicine, as it may aggravate those conditions.

Pilocarpine usually contracts the pupil, which lets less light into the eye, resulting in darkened or dim vision and reduced night vision. Blurred vision also may occur for several hours after taking the drug. Eye irritation and headache may occur, but they are less common side effects and may disappear over time.

Carbachol is another miotic that is prescribed as drops and helps open the eye's drain and increase the rate of fluid flowing out of the eye.

* Epinephrine compounds. These medications also increase the rate of aqueous humor flow out of the eye. Epinephrine (Epifrin, Eppy-N) and dipivefrin (Propine), drops may be prescribed in combination with pilocarpine or other glaucoma drugs. The average dose is one drop once or twice a day for epinephrine, and one drop every 12 hours for dipivefrin. Also, talk to your health care professional about taking epinephrine eye medicines before, during, and after dental surgery. Epinephrine in topical and injectable forms is often used in dental surgery, and use of the eye medication may increase side effects.

Common side effects of epinephrine may include headache; stinging, burning, redness or other eye irritation; and watery eyes. Eye pain is less common. These side effects may go away as your body adjusts to the drug.

You should alert your health care professional if you have eye diseases or problems in addition to glaucoma when taking dipivefrin because the drug can aggravate them. Side effects of this drug may include blurred vision, burning or stinging of the eye, headache, increased light sensitivity, and large pupils. They also may disappear over time.

* Beta blockers. These drugs reduce the amount of aqueous fluid produced in the eye. Although the oral form of this drug commonly is used to treat hypertension and angina and may lower intraocular pressure, it is the eyedrop form that is used to treat glaucoma patients. The antiglaucoma beta blockers include betaxolol (Betoptic), carteolol (Ocupress), levobetaxolol (Betaxon), levobunolol (Betagan), metipranolol (Optipranolol) and timolol (Betimol, Timoptic, Istalol). Common dosages are one drop, two times a day (although Istalol is a once-a-day drop). Levobunolol and timolol may be prescribed one drop, one or two times a day.

Be sure to tell your health care professional if you have any of the following conditions before taking beta blockers for glaucoma:

* Asthma, chronic bronchitis, emphysema or lung disease. Severe breathing difficulties, including death from bronchial tube spasms, have been reported with carteolol, levobunolol, metipranolol and timolol. The possibility of wheezing exists with betaxolol and levobetaxolol, but it is unusual.

* Diabetes, or low blood sugar. Antiglaucoma beta blockers may change blood sugar levels and may mask some signs and symptoms of these conditions, such as fast heart beat and trembling.

* Heart or blood vessel disease. Beta blockers for glaucoma may reduce the pulse rate and decrease heart activity.

* Overactive thyroid. Signs and symptoms of hyperthyroidism can be masked by beta blockers for glaucoma. Additionally, suddenly stopping the drugs can cause a dangerous increase in overactive thyroid symptoms.

* History of severe allergic reactions. Beta blockers for glaucoma may reduce the effectiveness of medicines used to treat severe allergies.

Before having any kind of surgery, dental procedures or emergency treatment, tell your attending health care professional that you are taking beta blockers for glaucoma because side effects of the drug may be increased.

Your eye may be more sensitive to light while taking betaxolol, carteolol and metipranolol. Wearing sunglasses and avoiding sun exposure and bright light can ease this discomfort.

Common side effects include decreased night vision and stinging of the eye upon application of the medication. Temporary blurred vision may occur with levobetaxolol and the gel-forming solution of timolol. It usually lasts from 30 seconds to five minutes. Less common side effects that may eventually disappear are acid or sour stomach, belching, brow ache, constipation, crusting of eyelashes, eye dryness, dry skin, indigestion, eye irritation, pain, redness and warmth or swelling of muscles.

* Carbonic anhydrase inhibitors. For many years these drugs were only available in pill form, but are now available as eyedrops. They reduce the amount of aqueous humor the eye produces. Brinzolamide (Azopt) and dorzolamide (Trusopt) are used for glaucoma and hypertension of the eye. A combination of Trusopt and Timoptic called Cosopt is commonly used. They are generally taken as one drop, three times a day. If you have severe kidney disease or liver diseases, talk to your health care professional before taking these drugs as their side effects can increase because of slower removal from your system.

Common side effects of brinzolamide that may disappear over time include temporary blurred vision after application and bitter sour or unusual taste in the mouth. Less common are burning or stinging of the eye upon application, dry eye and runny nose.

If you wear soft contact lenses and use brinzolamide, take your contacts out before taking the medication and wait 15 minutes before reinserting them. The preservative in the eyedrops can be absorbed by soft contact lenses and irritate your eyes.

If you are taking any eye preparations that contain silver nitrate, tell your health care professional before using dorzolamide drops because an adverse chemical reaction can occur. Also, notify your health care professional if you have kidney stones, since dorzolamide may worsen that condition.

Common side effects of dorzolamide include bitter taste in the mouth; burning or stinging when drop are applied; and a feeling of something in the eye. Less common are skin rashes, headache, nausea and unusual tiredness or weakness. These effects may disappear over time.

* Alpha-adrenergic agonists. These drops also reduce the amount of aqueous humor the eye produces and are used to treat glaucoma and hypertension of the eye. They are chemically related to drugs used to treat high blood pressure. Apraclonidine (Iopidine) often is prescribed when other glaucoma medications fail to sufficiently lower intraocular pressure. A higher concentration of this drug also is used after some kinds of glaucoma laser surgery to prevent or control a rise in eye pressure that is common after the procedure. Other drugs in this class are brimonidine (Alphagan) and Combigan (Alphagan and Timolol combined).

The typical prescription dose of apraclonidine for glaucoma control is one to two drops in the eye three times a day. Brimonidine is often taken as one drop, three times a day. Side effects that may or may not persist with both drugs include oral conjunctivitis, dizziness, dryness of mouth, eye discomfort and sensitivity of the eyes to light. As with other eyedrops that cause light sensitivity, wearing sunglasses and avoiding sun and bright light exposure can minimize this discomfort.

Before taking brimonidine, tell your health care professional if you have heart or blood vessel diseases, low blood pressure, kidney or liver disease or depression. The drug can increase blood pressure and aggravate depression. Side effects of the drug may increase if you have kidney or liver disease. Additionally, brimonidine should not be taken while taking, or within two weeks of taking, certain kinds of antidepressant drugs called monoamine oxidase (MAO) inhibitors.

Brimonidine drops contain preservatives that can be absorbed by soft contact lenses and irritate the eyes. If you wear soft contacts, remove them before putting drops in your eyes and wait 15 minutes before reinserting the lenses.

* Prostaglandin analogs. This class of drugs works near the drainage area of the eye to stimulate outflow of aqueous humor through pathways in the eye other than through the trabecular meshwork. Latanoprost (Xalatan), travoprost (Travatan Z) and bimatoprost (Lumigan) are new medications in this class used for glaucoma and hypertension of the eye. Typical dosage is one drop, once a day in the evening. Although this drug tends to be well tolerated by patients, it has some unusual side effects. The iris may turn browner in color after use over several months. Eyelid skin color also may darken. Eyelashes may become longer, thicker and darker. These changes occur only in the eye receiving the drops and may be permanent. Other possible side effects that may or may not persist include eye burning, itching, stinging, dryness of the eye and the feeling that something is in the eye.

Latanoprost, travoprost and bimatoprost may worsen other eye diseases such as iritis or uveitis. In eyes that have an intraocular lens replacement, which is common among patients who have been treated for cataracts, the drugs also may create a buildup of fluid in a part of the retina that allows the sight of fine details (called macular edema). As a result, reading and close work is difficult. If you have other eye or lens implants, tell your health care professional before taking these drugs. Additionally, notify your health care professional if you have kidney or liver diseases, as the drugs' side effects may increase from higher concentrations remaining in your system.

Like other kinds of glaucoma eyedrops, the prostaglandin analogs may make the eye more sensitive to light, and wearing sunglasses and avoiding exposure to bright light is advised. Additionally, contact lenses should be removed before using this drug and reinserted 15 minutes after drop application to avoid eye irritation.

A study by Alcon, the company that makes Travatan, indicates that Travatan may work best for African Americans with glaucoma. However, at this time, it is not known whether this difference was due to race or to heavily pigmented irises.

The oral medications for glaucoma are carbonic anhydrase inhibitors aimed at slowing production of aqueous humor in the eye. These include acetazolamide (Diamox), dichlorphenamide (Daranide) and methazolamide (Neptazane). Dosages of these pills vary. Side effects tend to be more common in the pill form of these drugs than the eyedrop form. They can include drowsiness, dizziness, lightheadedness and fatigue. They also can cause loss of potassium. Your health care professional may recommend you eat foods high in potassium, such as oranges or citrus fruit juices, or take a potassium supplement. However, you should not change your diet on your own, as the extra potassium may not be necessary and can be harmful.

In diabetics, the oral carbonic anhydrase inhibitors may raise blood and urine sugar levels. They also may produce shortness of breath and breathing problems in patients with emphysema or lung disease. They also may worsen kidney disease, kidney stones and liver diseases. If you have any of these conditions, make sure you discuss them with your health care professional before taking the drug. Your health care professional may recommend you drink more fluids while taking these medications to prevent development of kidney stones. Don't increase your fluid intake on your own without consulting your health care professional.

Other side effects that may stop over time include an increase in the frequency of urination; tingling or burning sensations in fingers and toes; diarrhea; a general feeling of illness; loss of appetite; metallic taste in the mouth; and nausea or vomiting. Your health care professional may also recommend taking the medication with meals to lessen the chance of stomach upset.

The most important thing to remember when taking glaucoma medications is to take them as directed by your health care professional. For the drugs to work effectively, they must be taken regularly and continuously, and you will need to take them as long as they control your eye pressure. If you forget to take your medication, contact your health care professional.

Surgery

If medications fail to lower your eye pressure, your health care professional may recommend surgery, either by laser or by conventional operative techniques. Sometimes, however, surgery is recommended as the first-line treatment.

Laser surgery uses a concentrated beam of light to open clogged drainage canals. Most laser surgeries can be done on an outpatient basis. First, the eye is numbed with drops that last throughout the procedure. Sometimes, an injection of a local anesthetic also is used to numb the eye. Then, health care professional holds a special lens to the eye, and the laser beam is aimed at the lens and reflected onto its target. The patient sees a bright light, similar to a camera flash, and usually feels little or no discomfort. After treatment, the eye may be irritated and vision may be blurred. Drops for soreness and sweeping inside the eye may be prescribed. Normal activities usually can be resumed after the procedure. Follow-up visits with your health care professional will be required to monitor intraocular pressure.

The following are types of laser surgeries:

* Trabeculoplasty. For patients with open-angle glaucoma, a laser is used to open the trabecular meshwork drainage area in the eye, which allows the aqueous humor fluid to move more freely and reduces intraocular pressure. In this procedure, the laser makes tiny burns in the meshwork that stretches and opens the drainage holes. Intraocular pressure is checked after the procedure, and patients usually are given drops to take a home for soreness or swelling inside the eye. Depending on the patient and the extent of the disease, only half of the meshwork may be treated in one surgery, and the remainder is treated in a later laser surgical session. If you have glaucoma in both eyes, only one eye will be treated at a time. The multisession approach prevents overcorrecting the problem.

Research shows that laser trabeculoplasty is very good at lowering intraocular pressure in some patients; however, its effects can wear off over time. Your doctor may suggest further treatment. Recently, another form of trabeculoplasty called "selective laser trabeculoplasty" has been introduced. It treats specific cells "selectively" and leaves the untreated portions of the trabecular meshwork intact. For this reason, SLT may be repeated several times and may also be an option for people with glaucoma who have not had success with traditional laser surgery or pressure-lowering drops.

* Iridotomy. For patients with angle-closure glaucoma, this surgery uses the laser beam to make a tiny hole in the iris to improve the flow of the aqueous humor to the drainage meshwork.

* Cyclophotocoagulation. Used most often in advanced or severe cases of glaucoma, this procedure uses the laser beam to destroy parts of the ciliary body that produces the aqueous humor fluid. With less fluid flowing through the eye, the intraocular pressure is reduced.

Conventional, incisional surgery often is recommended after medications and laser surgery have failed to control intraocular pressure. The surgery, called filtering microsurgery, creates a new opening for the intraocular fluid to leave the eye and is performed in a hospital or clinic with local anesthesia and sometimes with sedation. Patients cannot see with the eye undergoing the surgery, but they may hear noises from the instruments as the surgeon works.

The procedure involves removing a small piece of the white, outer shell of the eye, called the sclera, creating a channel through which the aqueous humor can flow. The sclera is covered by a thin clear layer of tissue called the conjunctiva. When the channel is created, the aqueous humor flows through it and under the conjunctiva, reducing pressure in the eye. According to the National Eye Institute, conventional surgery is 60 to 80 percent effective at lowering intraocular pressure.

After the procedure, patients are given eyedrops to ward off infection and swelling, and may be given pain medications for any postoperative discomfort. A patch also may be placed over the eye to protect it. Recovery takes about a week. Several follow-up visits with your health care professional will be required for the first few weeks after surgery to check eye pressure and functioning of the new channel. In some cases, a tiny wick-like drainage device is implanted to help lower pressure within the eye.

Like any form of surgery, both laser and conventional surgeries for glaucoma do carry risks. Although unusual, the complications that can occur include:

* infection

* bleeding

* swelling of blood vessels behind the eye

* undesirable changes in intraocular pressure

* loss of vision

* development of cataracts

Another approach to filtering surgery is the use of drainage devices such as Ahmed glaucoma shunt, Molteno implant, Baerveld implant, Express shunt. Their use has increased in recent years.

Prevention

Vision loss from glaucoma can be prevented if the disease is caught and treated in time. Because glaucoma rarely produces symptoms until it has progressed, regular eye examinations are the key to early detection and treatment. For those with no risk factors, the Glaucoma Research Foundation recommends a dilated eye exam be conducted at age 35 and age 40. It recommends such an exam should be done every two to four years after age 40, and after age 60, every one to two years. A dilated eye exam is necessary to check the optic nerve and should be conducted in addition to measuring your intraocular pressure.

You're at risk of developing glaucoma if you are older than age 60, are African American, have a family member who has glaucoma, are very nearsighted, are diabetic, had an eye injury in the past or have been taking steroid or cortisone medications. In such cases, you should have an eye exam including tests for glaucoma every one to two years.

If you are African American, your risk of developing the open-angle type of glaucoma is higher than for Caucasian people, according to the Glaucoma Research Foundation. Open-angle glaucoma accounts for 19 percent of all blindness among African-Americans, compared to only 6 percent in Caucasians.

Although there is no known way to prevent glaucoma, maintaining a healthy lifestyle may help you generally avoid diseases. Eating a balanced diet is the best way to ensure your body receives the proper nutrients it needs to function. Some of the vitamins and minerals that contribute to overall eye health include antioxidant vitamins A, C and E, and minerals zinc, copper and selenium. If you're concerned about your diet, talk with your health care professional about whether you should take nutritional supplements or make dietary changes.

Getting regular exercise also is a component of maintaining good overall health, and there is some evidence in the medical literature that regular aerobic exercise may help reduce eye pressure. In fact, some studies indicate that glaucoma patients who exercise at least three times a week can reduce their intraocular eye pressure an average of 20 percent, according to the Glaucoma Foundation. Before starting any exercise program, make sure you discuss possible effects on your intraocular pressure with your health care professional. The Glaucoma Research Foundation reports that some forms of glaucoma, such as angle- closure, are unresponsive to exercise, or run the risk of increasing eye pressure, such as in glaucoma patients with pigment dispersion syndrome. Additionally, exercises or yoga movements that place the head upside down hold the potential for increasing eye pressure and generally are discouraged for all glaucoma patients.

If you are diagnosed with glaucoma, it doesn't mean you will become blind. To control your disease and protect the sight you have, adhere to the prescription drug regimen recommended by your health care professional and have regular eye examinations to monitor the disease.

Facts to Know

* Glaucoma is a group of eye diseases that, when left untreated, damage the optic nerve and can lead to blindness.

* Often called the "sneak thief of sight," glaucoma usually produces no early warning signs and no symptoms until it has progressed to the point of stealing sight.

* More than four million Americans have glaucoma, but half don't know it, according to the Glaucoma Research Foundation.

* The risk of blindness from glaucoma is four times greater in African Americans than in Caucasians overall, and 15 times greater in African Americans age 45 to 65 than in Caucasians of the same age, according to the National Eye Institute.

* You are at risk for developing glaucoma if you are African American, are over age 60, have family members with glaucoma, are diabetic or are very nearsighted.

* Open-angle glaucoma is the most common form of glaucoma, occurring in more than three million Americans, according to the Glaucoma Foundation.

* Glaucoma can occur in children as well as adults. About one out of every 10,000 babies in the United States is born with glaucoma.

* Glaucoma has no cure, but it can be controlled. Treatment may include medications and surgery.

* Although treatment for glaucoma focuses on reducing pressure in the eye, it is possible to have higher than normal eye pressure and not have glaucoma.

* There is no way to prevent glaucoma, but getting regular, comprehensive eye examinations is the best way to identify disease before it affects vision.

Questions to Ask

Review the following Questions to Ask about glaucoma so you're prepared to discuss this important health issue with your health care professional.

* What are the risk factors for glaucoma and do I have any?

* How often should I have comprehensive eye examinations?

* What is my current intraocular pressure, and what is my target pressure?

* What kind of glaucoma do I have?

* What is the best treatment option for my glaucoma and why?

* Am I a candidate for glaucoma surgery, and if so, what kind?

* How should I take my glaucoma medication?

* What should I do if I miss a dose of my glaucoma medication?

* What side effects should I expect from my glaucoma medications, and how can I manage them?

* What kinds of side effects can result from taking glaucoma medications? When should I seek medical attention for those side effects?

Key Q&A

* Does glaucoma always lead to blindness?

No. Although glaucoma is a leading cause of blindness in the United States, it can be controlled and vision maintained if it is caught early. Because the disease usually produces no symptoms until it has begun to steal a person's sight, many of those who have it don't know it. In fact, the Glaucoma Research Foundation estimates that over four million Americans have glaucoma and half of them don't know it. That's why comprehensive eye examinations are recommended at least every two years for those at increased risk for the disease.

* What are the risk factors for glaucoma?

You are at risk of developing glaucoma if you are older than age 60, African American, have a family member who has glaucoma, are very nearsighted, are diabetic, had an eye injury in the past, or have been taking steroid or cortisone medications. In such cases, you should have an eye exam including tests for glaucoma every one to two years. If you are African American, your risk is especially great. The National Eye Institute reports that African Americans are five times more likely than Caucasians to develop glaucoma.

* What's the difference between high eye pressure and glaucoma?

Glaucoma is a group of eye diseases that damages the nerves carrying images from the eye to the brain. When the fluid inside the eye that nourishes the cornea and the lens can't flow properly through the eye, pressure in the eye builds. The pressure compresses the optic nerve and can damage it. Whether you develop glaucoma depends on how much pressure your optic nerve can take without being damaged.

* My eye pressure is 22 mm Hg. Does that mean I have glaucoma?

Not necessarily. Eye pressure is measured in millimeters of mercury (mm Hg), and it varies, even throughout the day. Generally, eye pressure readings between 10 and 20 mm Hg are considered normal, although a person may have glaucoma even with pressures in this range. It's a common misconception that having high intraocular pressure means you're a victim of glaucoma. In fact, you can have high intraocular pressure, known as ocular hypertension, and not have glaucoma. In some people, the optic nerve can tolerate pressures higher than the range considered normal. The only way to determine whether you have glaucoma is to have a comprehensive eye examination.

* What is the most common type of glaucoma?

Open-angle glaucoma is the most common form of the disease, occurring in more than three million Americans, according to the Glaucoma Foundation. In open- angle glaucoma, the angle where the cornea and the iris meet in the eye is open, but the aqueous humor fluid passes too slowly through the meshwork drain. As a result, the pressure in the eye gradually increases, compressing cells in the optic nerve. If left untreated, the compression eventually will cause the optic nerve cells to die, producing blindness.

* What is the most common treatment for glaucoma?

Glaucoma is most commonly treated with prescription medications in the form of eyedrops, and many of the prescriptions must be taken several times a day. Glaucoma medications, which can come in topical or oral form, are designed to lower pressure in the eye. Other topical medications may be inserts of thin wafers you place in the corner of the eye, or eye ointments and gels. Most topical medications reduce eye pressure by either increasing the flow of the aqueous humor fluid out of the eye or reducing the amount of the fluid produced in the eye. Oral glaucoma medications come in pill and tablet form and are aimed at slowing production of fluid in the eye.

* Can surgery help my open-angle glaucoma?

Possibly. If medications fail to lower your eye pressure, your health care professional may recommend surgery, either by laser or by conventional operative techniques. Sometimes, however, surgery is recommended as the first-line treatment. In a procedure called laser trabeculoplasty, a beam of concentrated light is used to open the drainage area in the eye, which allows the fluid in the eye to move more freely and reduces intraocular pressure. The effects of this treatment may wear off over time. Once the entire drainage area has been treated with the laser, further treatments may be ineffective. Conventional surgery for glaucoma, also called filtering microsurgery, creates a new opening for the intraocular fluid to leave the eye. It often is recommended after medications and/or laser surgery have failed to control intraocular pressure. The surgery involves removing a small piece of the white, outer shell of the eye, to create a channel through which the aqueous humor fluid can flow. This incisional surgery has been between 60 percent and 80 percent effective in lowering pressure, according to the National Eye Institute.

* What can I do to prevent glaucoma?

There is no known way to prevent glaucoma. But, vision loss from glaucoma can be prevented if the disease is caught and treated in time. Because glaucoma rarely produces symptoms until it has progressed, regular eye examinations are the key to early detection and treatment. For those with no risk factors, the Glaucoma Research Foundation recommends a dilated eye exam be conducted at age 35 and age 40. After age 40, it recommends such an exam should be done every two to four years, and after age 60, every one to two years. If you are at risk for glaucoma, you should have an eye exam every one to two years.

* I've heard people with glaucoma should take special vitamin supplements. What should I be taking and in what dose?

Although glaucoma can't be prevented, maintaining a healthy lifestyle and eating nutritious foods may help you generally avoid diseases. Eating a balanced diet is the best way to ensure your body receives the proper nutrients it needs to function. Some of the vitamins and minerals that may contribute to overall eye health include antioxidant vitamins A, C and E, and minerals zinc, copper and selenium. If you're concerned about your diet, talk with your health care professional about whether you should take nutritional supplements or make dietary changes.

* Can exercise help my glaucoma?

Getting regular exercise also is a component of maintaining good overall health, and there is some evidence in the medical literature that regular aerobic exercise may help reduce eye pressure. Before starting any exercise program, make sure you discuss possible effects on your intraocular pressure with your health care professional. Some forms of glaucoma, such as angle-closure, are unresponsive to exercise or run the risk of increasing eye pressure, such as in glaucoma patients with pigment dispersion syndrome. Additionally, exercises or yoga movements that place the head upside down hold the potential for increasing eye pressure and generally are discouraged for all glaucoma patients. Talk with your health care professional about what kind of exercise is best for you.

* Is there any special way I should take my glaucoma eye drops?

The most important thing to remember when taking glaucoma medications is to take them as directed by your health care professional. Make sure you understand how and when to take your medications and how to properly store them. For the drugs to work effectively, they must be taken regularly and continuously, and you will need to take them as long as they control your eye pressure.

Organizations and Support

For information and support on coping with Glaucoma, please see the recommended organizations, books and Spanish-language resources listed below.

Organizations

American Academy of Ophthalmology

Website: http://www.aao.org

Address: P.O. Box 7424

San Francisco, CA 94120

Phone: 415-561-8500

Email: customer_service@aao.org

American Council of the Blind

Website: http://www.acb.org

Address: 1155 15th St., NW, Suite 1004

Washington, DC 20005

Hotline: 1-800-424-8666

Phone: 202-467-5081

American Health Assistance Foundation

Website: http://www.ahaf.org

Address: 22512 Gateway Center Drive

Clarksburg, MD 20871

Hotline: 1-800-437-AHAF (2423)

Glaucoma Foundation

Website: http://www.glaucomafoundation.org

Address: 80 Maiden Lane, Suite 700

New York, NY 10038

Phone: 212-285-0080

Email: info@glaucomafoundation.org

Glaucoma Research Foundation

Website: http://www.glaucoma.org

Address: 251 Post Street, Suite 600

San Francisco, CA 94108

Phone: 415-986-3162

National Eye Health Education Program

Website: http://www.nei.nih.gov/nehep

Address: National Eye Institute Information Office

31 Center Drive MSC 2510

Bethesda, MD 20892

Phone: 301-496-5248

Email: 2020@nei.nih.gov

Prevent Blindness America

Website: http://www.preventblindness.org

Address: 211 West Wacker Drive, Suite 1700

Chicago, IL 60606

Hotline: 1-800-331-2020

Schepens Eye Research Institute

Website: http://www.schepens.harvard.edu

Address: 20 Staniford Street

Boston, MA 02114

Phone: 617-912-2569

Books

Coping with Glaucoma

by Edith Marks, Rita Mountauredes

Glaucoma: A Patient's Guide to the Disease

by Graham E. Trope

Spanish-language Resources

Medline Plus: Glaucoma

Website: http://www.nlm.nih.gov/medlineplus/spanish/ency/article/001620.htm

Address: Customer Service

8600 Rockville Pike

Bethesda, MD 20894

Email: custserv@nlm.nih.gov

American Academy of Ophthalmology

Website: http://www.aao.org/eyesmart/diseases-es/glaucoma.cfm

American Academy of Ophthalmology

Phone: 415-447-0213

Email: eyesmart@aao.org

Glaucoma Research Foundation

Website: http://www.glaucoma.org/learn/aqu_es_el_glauc.php

Address: 251 Post Street, Suite 600

San Francisco, CA 94108

Hotline: 1-800-826-6693

Phone: 415-986-3162

Email: question@glaucoma.org

National Eye Institute

Website: http://www.nei.nih.gov/health/espanol/glaucoma_paciente.asp

Address: Information Office

31 Center Drive MSC 2510

Bethesda, MD 20892

Phone: 301-496-5248

Email: 2020@nei.nih.gov

"Protecting your vision against glaucoma." The National Eye Institute. 2008. http://www.nei.nih.gov. Accessed October 2008.

"Are you at risk for glaucoma?" The Glaucoma Research Foundation. 2008. http://www.glaucoma.org. Accessed October 2008.

"Glaucoma facts and stats." The Glaucoma Research Foundation. April 2008. http://www.glaucoma.org. Accessed October 2008.

"What is normal tension glaucoma?" The Glaucoma Research Foundation. http://www.glaucoma.org. Accessed October 2008.

"Glaucoma medications." The Glaucoma Research Foundation. http://www.glaucoma.org. Accessed October 2008.

"Glaucoma." The National Eye Institute. March 2008. http://www.nei.nih.gov. Accessed October 2008.

"Iopidine eye." RxList. http://www.rxlist.com. Accessed October 2008.

"Travatan." CenterWatch Clinical Trials Listing Service. June 2008, http://www.centerwatch.com. Accessed October 2008.

"Does extended wear of a tight necktie caused raised intraocular pressure?" J Glaucoma. 2005 Dec;14(6):508-10. http://www.ncbi.nlm.nih.gov. Accessed October 2008.

"Selective laser trabeculoplasty (SLT)." The Glaucoma Research Foundation. September 2008. http://www.glaucoma.org. Accessed October 2008.

"Hispanic Americans at increased risk for glaucoma." The Glaucoma Research Foundation. January 2008. http://www.glaucoma.org. Accessed October 2008.

"Don't Lose Sight of Glaucoma." National Eye Institute. April 2000. http://www.nei.nih.gov. Accessed September 2003.

Glaucoma Research Foundation. Updated Aug. 2003. http://www.glaucoma.org. Accessed September 2003.

MEDLINEplus Health Information, National Library of Medicine. Updated March 2003. http://www.nlm.nih.gov. Accessed September 2003.

The Glaucoma Foundation. Copyright 2003. http://www.glaucomafoundation.org. Accessed September 2003.

"Eye Health/Glaucoma" American Academy of Ophthalmology. Medem Medical Library. Copyright 2002-2003. http://www.medem.com. Accessed September 2003.

"Frequently Asked Questions About Glaucoma." Prevent Blindness America. Updated May 2003. http://www.preventblindness.org. Accessed September 2003.

"Tight Neckties May Increase Eye Pressure." The American Health Assistance Foundation. July 2003. http://www.ahaf.org. Accessed September 2003.
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