Glaucoma 

What You Should Know 

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES 

National Institutes of Health 

National Eye Institute 
B

The National Eye Institute (NEI) conducts and supports 

research that leads to sight-saving treatments and plays a 

key role in reducing visual impairment and blindness. NEI is 

part of the National Institutes of Health, an agency of the 

U.S. Department of Health and Human Services. 

For more information, contact— 

National Eye Institute 

National Institutes of Health 

2020 Vision Place 

Bethesda, MD 20892–3655 

Telephone: 301–496–5248 

E-mail: 2020@nei.nih.gov 

Website: www.nei.nih.gov
Contents

What You Should Know About 

Glaucoma 1–4 

Glaucoma Symptoms 4–6 

Glaucoma Treatments 7–13 

What You Can Do 13–16 

Loss of Vision 16 

Where Can I Get More Information? 17–19 

How Should I Use My Glaucoma Eyedrops? 21 

 

 

 

 

 

What You Should Know About Glaucoma
 

What You Should Know About Glaucoma

This booklet is for people with glaucoma and their families 

and friends. It provides information about open-angle 

glaucoma, the most common form of glaucoma. This booklet 

answers questions about the causes and symptoms of this 

disease and discusses diagnosis and types of treatment. 

What is glaucoma?

Glaucoma is a group of diseases that damage the eye’s 

optic nerve and can result in vision loss and blindness. 

However, with early detection and treatment, you can 

often protect your eyes against serious vision loss. 

The optic nerve 

The optic nerve is a bundle of more than 1 million 

nerve fibers. It connects the retina to the brain. 

(See diagram above.) The retina is the light-sensitive 

tissue at the back of the eye. A healthy optic nerve is 

necessary for good vision. 

Cornea

Pupil 

Lens

Retina

Vitreous  gel

Optic 

nerve

Macula

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How does the optic nerve get damaged by openangle glaucoma?

Several large studies have shown that eye pressure is a 

major risk factor for optic nerve damage. In the front of 

the eye is a space called the anterior chamber. A clear fluid 

flows continuously in and out of the chamber and nourishes 

nearby tissues. The fluid leaves the chamber at the open 

angle where the cornea and iris meet. (See diagram below.) 

When the fluid reaches the angle, it flows through a spongy 

meshwork, like a drain, and leaves the eye. 

Fluid pathway is shown in teal.
	

In open-angle glaucoma, even though the drainage angle is 

“open,” the fluid passes too slowly through the meshwork 

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What You Should Know About Glaucoma

drain. Since the fluid builds up, the pressure inside the eye 

rises to a level that may damage the optic nerve. When 

the optic nerve is damaged from increased pressure, openangle glaucoma—and vision loss—may result. That’s why 

controlling pressure inside the eye is important. 

Another risk factor for optic nerve damage relates to blood 

pressure. Thus, it is important to also make sure that your 

blood pressure is at a proper level for your body by working 

with your medical doctor. 

Can I develop glaucoma if I have increased eye 

pressure?

Not necessarily. Not every person with increased eye 

pressure will develop glaucoma. Some people can tolerate 

higher levels of eye pressure better than others. Also, a 

certain level of eye pressure may be high for one person but 

normal for another. 

Whether you develop glaucoma depends on the level 

of pressure your optic nerve can tolerate without being 

damaged. This level is different for each person. That’s why 

a comprehensive dilated eye exam is very important. It can 

help your eye care professional determine what level of eye 

pressure is normal for you. 
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Can I develop glaucoma without an increase in my 

eye pressure?

Yes. Glaucoma can develop without increased eye pressure. 

This form of glaucoma is called low-tension or normaltension glaucoma. It is a type of open-angle glaucoma. 

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Who is at risk for open-angle 

glaucoma? 

Anyone can develop glaucoma. Some people, listed 

below, are at higher risk than others: 

African Americans over age 40 

Everyone over age 60, especially Mexican 

Americans 

People with a family history of glaucoma 

A comprehensive dilated eye exam can reveal more 

risk factors, such as high eye pressure, thinness of the 

cornea, and abnormal optic nerve anatomy. In some 

people with certain combinations of these high-risk 

factors, medicines in the form of eyedrops reduce the 

risk of developing glaucoma by about half. 

Glaucoma Symptoms

At first, open-angle glaucoma has no symptoms. It causes 

no pain. Vision stays normal. Glaucoma can develop in one 

or both eyes. 

Without treatment, people with glaucoma will slowly 

lose their peripheral (side) vision. As glaucoma remains 
Glaucoma Symptoms
 

untreated, people may miss objects to the side and out of 

the corner of their eye. They seem to be looking through 

a tunnel. Over time, straight-ahead (central) vision may 

decrease until no vision remains. 

Normal vision
 

The same scene as viewed 

by a person with glaucoma
 

How is glaucoma detected?

Glaucoma is detected through a comprehensive dilated eye 

exam that includes the following: 

Visual acuity test. This eye chart test measures how well you 

see at various distances. 

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Visual field test. This test measures your peripheral (side 

vision). It helps your eye care professional tell if you have 

lost peripheral vision, a sign of glaucoma. 

Dilated eye exam. In this exam, drops are placed in 

your eyes to widen, or dilate, the pupils. Your eye care 

professional uses a special magnifying lens to examine your 

retina and optic nerve for signs of damage and other eye 

problems. After the exam, your close-up vision may remain 

blurred for several hours. 

Tonometry is the 

measurement of pressure 

inside the eye by using an 

instrument (right) called a 

tonometer. Numbing drops 

may be applied to your eye 

for this test. A tonometer measures pressure 

inside the eye to detect glaucoma. 

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Pachymetry is the measurement of the thickness of your 

cornea. Your eye care professional applies a numbing drop 

to your eye and uses an ultrasonic wave instrument to 

measure the thickness of your cornea. 

Can glaucoma be cured?

No. There is no cure for glaucoma. Vision lost from the 

disease cannot be restored. 
 

 

 

 

Glaucoma Treatments
 

Glaucoma Treatments

Immediate treatment for early-stage, open-angle glaucoma 

can delay progression of the disease. That’s why early 

diagnosis is very important. 

Glaucoma treatments include medicines, laser trabeculoplasty, 

conventional surgery, or a combination of any of these. 

While these treatments may save remaining vision, they do 

not improve sight already lost from glaucoma. 

Medicines. Medicines, in the form 

of eyedrops or pills, are the most 

common early treatment for 

glaucoma. Taken regularly, these 

eyedrops lower eye pressure. Some 

medicines cause the eye to make 

less fluid. Others lower pressure by 

helping fluid drain from the eye. 

Before you begin glaucoma treatment, tell your eye care 

professional about other medicines and supplements that 

you are taking. Sometimes the drops can interfere with the 

way other medicines work. 

Glaucoma medicines need to be taken regularly as directed 

by your eye care professional. Most people have no 

problems. However, some medicines can cause headaches or 7
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other side effects. For example, drops may cause stinging, 

burning, and redness in the eyes. 

Many medicines are available to treat glaucoma. If you have 

problems with one medicine, tell your eye care professional. 

Treatment with a different dose or a new medicine may be 

possible. 

Because glaucoma often has no symptoms, people may 

be tempted to stop taking, or may forget to take, their 

medicine. You need to use the drops or pills as long as they 

help control your eye pressure. Regular use is very important. 

Make sure your eye care professional shows you how to put 

the drops into your eye. For tips on using your glaucoma 

eyedrops, see the inside back cover of this booklet. 

Laser trabeculoplasty. Laser trabeculoplasty helps fluid 

drain out of the eye. Your doctor may suggest this step 

at any time. In many cases, you will need to keep taking 

glaucoma medicines after this procedure. 

Laser trabeculoplasty is performed in your doctor’s office or eye 

clinic. Before the surgery, numbing drops are applied to your 

eye. As you sit facing the laser machine, your doctor holds a 

special lens to your eye. A high-intensity beam of light is aimed 

through the lens and reflected onto the meshwork inside your 

eye. You may see flashes of bright green or red light. The laser 

makes several evenly spaced burns that stretch the drainage 

holes in the meshwork. This allows the fluid to drain better. 

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Glaucoma Treatments
 

Like any surgery, laser surgery can cause side effects, such 

as inflammation. Your doctor may give you some drops to 

take home for any soreness or inflammation inside the eye. 

You will need to make several follow-up visits to have your 

eye pressure and eye monitored. 

If you have glaucoma in both eyes, usually only one eye will 

be treated at a time. Laser treatments for each eye will be 

scheduled several days to several weeks apart. 

Studies show that laser surgery can be very good at reducing 

the pressure in some patients. However, its effects can wear 

off over time. Your doctor may suggest further treatment. 

Conventional surgery. Conventional surgery makes a new 

opening for the fluid to leave the eye. (See diagram on the 

next page.) Your doctor may suggest this treatment at any 

time. Conventional surgery often is done after medicines 

and laser surgery have failed to control pressure. 

Conventional surgery, called 

trabeculectomy, is performed in an 

operating room. Before the surgery, 

you are given medicine to help 

you relax. Your doctor makes small 

injections around the eye to numb 

it. A small piece of tissue is removed 

to create a new channel for the fluid 9
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to drain from the eye. This fluid will drain between the eye 

tissue layers and create a blister-like “filtration bleb.” 

For several weeks after the surgery, you must put drops in the 

eye to fight infection and inflammation. These drops will be 

different from those you may have been using before surgery. 

Conventional surgery is performed on one eye at a time. 

Usually the operations are four to six weeks apart. 

Conventional surgery is about 60 to 80 percent effective 

at lowering eye pressure. If the new drainage opening 

narrows, a second operation may be needed. Conventional 

surgery works best if you have not had previous eye 

surgery, such as a cataract operation. 

Conventional surgery makes a new opening 

for the fluid to leave the eye. 10
 

 

 

 

 

 

 

Glaucoma Treatments
 

Sometimes after conventional surgery, your vision may not be 

as good as it was before conventional surgery. Conventional 

surgery can cause side effects, including cataract, problems 

with the cornea, inflammation, infection inside the eye, or low 

eye pressure problems. If you have any of these problems, tell 

your doctor so a treatment plan can be developed. 

What are some other forms of glaucoma?

Open-angle glaucoma is the most common form. Some 

people have other types of the disease. 

In low-tension or normal-tension glaucoma, optic nerve 

damage and narrowed side vision occur in people with 

normal eye pressure. Lowering eye pressure at least 30 

percent through medicines slows the disease in some people. 

Glaucoma may worsen in others despite low pressures. 

A comprehensive medical history is important to identify 

other potential risk factors, such as low blood pressure, that 

contribute to low-tension glaucoma. If no risk factors are 

identified, the treatment options for low-tension glaucoma 

are the same as for open-angle glaucoma. 

In angle-closure glaucoma, the fluid at the front of the 

eye cannot drain through the angle and leave the eye. 

The angle gets blocked by part of the iris. People with 

this type of glaucoma may have a sudden increase in eye 

pressure. Symptoms include severe pain and nausea, as well 11
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as redness of the eye and blurred vision. If you have these 

symptoms, you need to seek treatment immediately. This 

is a medical emergency. If your doctor is unavailable, go to 

the nearest hospital or clinic. Without treatment to restore 

the flow of fluid, the eye can become blind. Usually, prompt 

laser surgery and medicines can clear the blockage, lower 

eye pressure, and protect vision. 

In congenital glaucoma, children are born with a defect in 

the angle of the eye that slows the normal drainage of fluid. 

These children usually have obvious symptoms, such as cloudy 

eyes, sensitivity to light, and excessive tearing. Conventional 

surgery typically is the suggested treatment, because 

medicines are not effective and can cause more serious side 

effects in infants and be difficult to administer. Surgery is 

safe and effective. If surgery is done promptly, these children 

usually have an excellent chance of having good vision. 

Secondary glaucomas can develop as complications of other 

medical conditions. For example, a severe form of glaucoma 

is called neovascular glaucoma, and can be a result from 

poorly controlled diabetes or high blood pressure. Other 

types of glaucoma sometimes occur with cataract, certain eye 

tumors, or when the eye is inflamed or irritated by a condition 

called uveitis. Sometimes glaucoma develops after other eye 

surgeries or serious eye injuries. Steroid drugs used to treat eye 

inflammations and other diseases can trigger glaucoma in some 

people. There are two eye conditions known to cause secondary 

forms of glaucoma. Pigmentary glaucoma occurs when pigment 

from the iris sheds off and blocks the meshwork, slowing fluid 

drainage. Pseudoexfoliation glaucoma occurs when extra 

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What You Can Do
 

material is produced and shed off internal eye structures and 

blocks the meshwork, again slowing fluid drainage. 

Depending on the cause of these secondary glaucomas, 

treatment includes medicines, laser surgery, or conventional 

or other glaucoma surgery. 

What research is being done?

Through studies in the laboratory and with patients, NEI is 

seeking better ways to detect, treat, and prevent vision loss 

in people with glaucoma. For example, researchers have 

discovered genes that could help explain how glaucoma 

damages the eye. 

NEI also is supporting studies to learn more about who is 

likely to get glaucoma, when to treat people who have 

increased eye pressure, and which treatment to use first. 

What You Can Do

If you are being treated for glaucoma, be sure to take 

your glaucoma medicine every day. See your eye care 

professional regularly. 

You also can help protect the vision of family members 

and friends who may be at high risk for glaucoma—African 

Americans over age 40; everyone over age 60, especially 

Mexican Americans; and people with a family history of the 

disease. Encourage them to have a comprehensive dilated 13
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eye exam at least once every two years. Remember that 

lowering eye pressure in the early stages of glaucoma slows 

progression of the disease and helps save vision. 

Medicare covers an annual comprehensive dilated eye exam 

for some people at high risk for glaucoma. These people 

include those with diabetes, those with a family history of 

glaucoma, and African Americans age 50 and older. 

What should I ask my eye care professional?
 

You can protect yourself against vision loss by working in 

partnership with your eye care professional. Ask questions 

and get the information you need to take care of yourself 

and your family. 

What are some questions to ask?

About my eye disease or disorder... 

• What is my diagnosis? 

• What caused my condition? 

• Can my condition be treated? 

• How will this condition affect my vision now and in the future? 

• Should I watch for any particular symptoms and notify 

you if they occur? 

• Should I make any lifestyle changes? 

About my treatment... 

• What is the treatment for my condition? 

• When will the treatment start and how long will it last? 14
 

 

 

 

 

What You Can Do
 

• What are the benefits of this treatment and how 

successful is it? 

• What are the risks and side effects associated with this 

treatment? 

• Are there foods, medicines, or activities I should avoid 

while I’m on this treatment? 

• If my treatment includes taking medicine, what should I 

do if I miss a dose? 

• Are other treatments available? 

About my tests... 

• What kinds of tests will I have? 

• What can I expect to find out from these tests? 

• When will I know the results? 

• Do I have to do anything special to prepare for any of 

the tests? 

• Do these tests have any side effects or risks? 

• Will I need more tests later? 

Other suggestions 

• If you don’t understand your eye care professional’s 

responses, ask questions until you do understand. 

• Take notes or get a friend or family member to take notes 

for you. Or, bring a tape recorder to help you remember 

the discussion. 

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• Ask your eye care professional to write down his or her 

instructions to you. 

• Ask your eye care professional for printed material about 

your condition. 

• If you still have trouble understanding your eye care 

professional’s answers, ask where you can go for more 

information. 

• Other members of your healthcare team, such as nurses and 

pharmacists, can be good sources of information. Talk to 

them, too. 

Today, patients take an active role in their health care. Be 

an active patient about your eye care. 

Loss of Vision

If you have lost some sight from glaucoma, ask your eye 

care professional about low vision services and devices that 

may help you make the most of your remaining vision. Ask 

for a referral to a specialist in low vision. Many community 

organizations and agencies offer information about low 

vision counseling, training, and other special services for 

people with visual impairments. 

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Where Can I Get More Information?

Where Can I Get More Information?

For more information about glaucoma, contact the 

following organizations: 

American Academy of Ophthalmology* 

P.O. Box 7424 

San Francisco, CA 94120–7424 

415–561–8500 

1–800–391–3937 (Eye Care America Glaucoma Project) 

www.aao.org 

American Optometric Association* 

243 North Lindbergh Boulevard 

St. Louis, MO 63141–7851 

314–991–4100 

www.aoa.org 

The Glaucoma Foundation 

80 Maiden Lane, Suite 1206 

New York, NY 10038 

212–285–0080 

E-mail: info@glaucomafoundation.org 

www.glaucoma-foundation.org/ 

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Glaucoma Research Foundation 

251 Post Street, Suite 600 

San Francisco, CA 94108 

1–800–826–6693 

415–986–3162 

www.glaucoma.org 

National Eye Institute* 

National Institutes of Health 

2020 Vision Place 

Bethesda, MD 20892–3655 

301–496–5248 

E-mail: 2020@nei.nih.gov 

www.nei.nih.gov 

Prevent Blindness America 

211 West Wacker Drive, Suite 1700 

Chicago, IL 60606 

1–800–331–2020 

312–363–6001 

E-mail: info@preventblindness.org 

www.preventblindness.org 

*These organizations also provide information on low vision. 

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Where Can I Get More Information?

For more information about low vision services and 

programs, contact the following organizations: 

American Foundation for the Blind 

2 Penn Plaza, Suite 1102 

New York, NY 10121 

1–800–232–5463 

212–502–7600 

E-mail: afbinfo@afb.net 

www.afb.org 

Council of Citizens with Low Vision International 

1–800–733–2258 

Lighthouse International 

111 East 59th Street 

New York, NY 10022–1202 

1–800–334–5497 

1–800–829–0500 

212–821–9200 

212–821–9713 (TDD) 

E-mail: info@lighthouse.org 

www.lighthouse.org 

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How should I use my glaucoma 

eyedrops? 

How Should I Use My Glaucoma Eyedrops?

If eyedrops have been prescribed for treating 

your glaucoma, you need to use them properly, as 

instructed by your eye care professional. Proper use of 

your glaucoma medication can improve the medicine’s 

effectiveness and reduce your risk of side effects. 

To properly apply your eyedrops, follow these steps: 

Wash your hands. 

Hold the bottle upside down. 

Tilt your head back. 

Hold the bottle in one hand and place it as 

close as possible to the eye. 

With the other hand, pull down your lower 

eyelid. This forms a pocket. 

Place the prescribed number of drops into the 

lower eyelid pocket. If you are using more than 

one eyedrop, be sure to wait at least 5 minutes 

before applying the second eyedrop. 

Close your eye OR press the lower lid lightly 

with your finger for at least 1 minute. Either of 

these steps keeps the drops in the eye and helps 

prevent the drops from draining into the tear 

duct, which can increase your risk of side effects. 
U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES 

National Institutes of Health 

National Eye Institute 

NIH Publication No: 10–651 

Revised 06/11