Glaucoma
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. READ MORE
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. Primary open angle glaucoma (POAG) is a leading cause of blindness in the United States, according to the National Eye Institute. A study published in the journal Archives of Ophthalmology estimates that 2.2 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 damaging a person's sight.
Although glaucoma has no cure, it can be controlled and vision can be maintained if it is detected early. That's why comprehensive eye examinations are recommended at least every two years after age 35 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. Older Hispanics/Latinos are also at elevated risk, the highest prevalence being among those of Mexican descent.
Other risk factors include:
Another risk factor for glaucoma is high pressure within the eye. Pressure in the eye is known as intraocular pressure. However, it is a common misconception that having high intraocular pressure means you have 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, known as the cornea. The iris is the colored part of the eye containing muscles that make the pupil open and close. The pupil is the black area in the center of the eye where light enters. Located inside the eye, behind the iris, is the lens. The lens is 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 optic nerve's signals into the images that 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:
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. You should receive a comprehensive eye examination, which may include any of the following painless tests:
Glaucoma treatments generally focus on reducing intraocular pressure to a level the 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). It varies, even throughout a single day. Generally, eye pressure readings between 10 and 21 mm Hg are considered normal, although a person may have glaucoma even with pressures in this range.
Most newly diagnosed cases of glaucoma are treated with medications, which come in topical and oral form. Topical medications may be eyedrops or eye ointments. Oral glaucoma medications come in pill and tablet form.
The most common topical medications are eyedrops, and some of them must be taken once or 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:
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 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. Then a 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 person 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 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:
Vision loss from glaucoma can be prevented if the disease is detected 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 American Academy of Ophthalmology recommends a complete eye exam once in your 20s and twice in your 30s. You should have a baseline comprehensive eye exam at age 40, and your eye doctor will recommend follow-up exams based on your family history and the results of the baseline exam. After age 65, it's important to have a complete eye exam every year or two.
You're at risk of developing glaucoma if you are older than age 60; are African American, an older Latino, especially of Mexican descent; have a family member who has glaucoma; are very nearsighted; are diabetic; have had an eye injury in the past; or have been taking steroid or cortisone medications regularly. In such cases, you should have an eye exam including tests for glaucoma every one to two years after age 35.
If you are African American, your risk of developing the open-angle type of glaucoma is higher than for Caucasian people, according to the National Eye Institute. Open-angle glaucoma accounts for 19 percent of all blindness among African-Americans, compared to only 6 percent in Caucasians. Older Hispanics/Latinos are also at elevated risk, with the highest prevalence for glaucoma being among those of Mexican descent. Individuals who are far-sighted (hyperopic), with narrow angles and of Asian descent are at risk for acute or chronic angle glaucoma.
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 exercise that raises the pulse rate by just 20 percent to 25 percent (for example, a brisk walk) for 20 minutes, at least four times a week, can help reduce intraocular pressure, 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. Some forms of glaucoma, such as angle-closure, are unresponsive to exercise or run the risk of increasing eye pressure. Additionally, exercises or yoga movements that hold the head upside down have the potential for increasing eye pressure and generally are discouraged for everyone with glaucoma.
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.
Review the following Questions to Ask about glaucoma so you're prepared to discuss this important health issue with your health care professional.
You are at risk of developing glaucoma if you are older than age 60, African American, Latino (especially of Mexican descent), have a family member who has glaucoma, are very nearsighted, are diabetic, have had an eye injury in the past or have been taking steroid or cortisone medications for a length of time. In such cases, you should have an eye exam including tests for glaucoma every one to two years after age 35. If you are African American, your risk is especially great. The National Eye Institute reports that African Americans are six to eight times more likely than Caucasians to develop 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.
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 have 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.
Open-angle glaucoma is the most common form of the disease. 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.
Glaucoma is most commonly treated with prescription medications in the form of eyedrops. Many of the prescriptions must be taken once to several times a day. Glaucoma medications, which can come in topical or oral form, are designed to lower pressure in the eye. Other glaucoma medications come in the form of a gel. 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.
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 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. This allows the fluid in the eye to move more freely and reduces intraocular pressure. The effects of laser 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.
There is no known way to prevent glaucoma. However, vision loss from glaucoma can be prevented if the disease is detected 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 American Academy of Ophthalmology recommends a complete eye exam once in your 20s and twice in your 30s. You should have a baseline comprehensive eye exam at age 40, and your eye doctor will recommend follow-up exams based on your family history and the results of the baseline exam. After age 65, it's important to have a complete eye exam every year or two.
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.
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. Exercise can increase the pressure in pigmentary glaucoma. Additionally, exercises or yoga movements that hold the head upside down have the potential for increasing eye pressure and generally are discouraged for everyone with glaucoma. Talk with your health care professional about what kind of exercise is best for you.
The most important thing to remember when taking glaucoma medications is to take them exactly 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 without interruption. You will need to take them as long as they control your eye pressure.
For information and support on coping with Glaucoma, please see the recommended organizations, books and Spanish-language resources listed below.
American Academy of Ophthalmology
Website: https://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: https://www.acb.org
Address: 1155 15th St., NW, Suite 1004
Washington, DC 20005
Hotline: 1-800-424-8666
Phone: 202-467-5081
BrightFocus Foundation
Website: https://www.brightfocus.org/
Address: 22512 Gateway Center Drive
Clarksburg, MD 20871
Hotline: 1-800-437-2423
Glaucoma Foundation
Website: https://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: https://www.glaucoma.org
Address: 251 Post Street, Suite 600
San Francisco, CA 94108
Phone: 415-986-3162
National Eye Health Education Program
Website: https://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: https://preventblindness.org/
Address: 211 West Wacker Drive, Suite 1700
Chicago, IL 60606
Hotline: 1-800-331-2020
Schepens Eye Research Institute
Website: https://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: https://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: https://www.aao.org/salud-ocular/enfermedades/que-es-la-glaucoma
American Academy of Ophthalmology
Phone: 415-447-0213
Email: eyesmart@aao.org
Glaucoma Research Foundation
Website: https://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





Support Our Mission