Glaucoma is the name for a group of eye diseases that damage the optic nerve. This nerve carries information from the eye to the brain. When the nerve is damaged, you can lose your vision.
Glaucoma is one of the most common causes of legal blindness in the world. At first, people with glaucoma lose side (peripheral) vision. But if the disease isn't treated, vision loss may get worse. This can lead to total blindness over time.
There are three types of glaucoma.
The exact cause isn't known. Experts think that increased pressure in the eye (intraocular pressure) may cause the nerve damage in many cases. But some people who have glaucoma have normal eye pressure.
Some people get glaucoma after an eye injury or after eye surgery. Some medicines (corticosteroids) that are used to treat other diseases may also cause glaucoma.
If you have OAG, the only symptom you are likely to notice is loss of vision. You may not notice this until it is serious. That's because the eye that is less affected makes up for the loss at first. Side vision is often lost before central vision.
Symptoms of CAG can be mild, with symptoms like blurred vision that last only for a short time. Severe signs of CAG include longer-lasting episodes of blurred vision or pain in or around the eye. You may also see coloured halos around lights, have red eyes, or feel sick to your stomach and vomit.
In congenital glaucoma, signs can include watery eyes and sensitivity to light. Your baby may rub his or her eyes, squint, or keep the eyes closed much of the time.
Glaucoma can be diagnosed:
An optometrist can screen you for glaucoma but will have to consult an ophthalmologist to confirm the diagnosis.
Glaucoma can't be cured. But there are things you can do to help stop more damage to the optic nerve. To help keep your vision from getting worse, you'll probably need to use medicine (most likely eyedrops) every day. You may also need laser treatment or surgery. You'll also need regular checkups with your eye doctor.
If you have vision loss, you can keep your quality of life. You can use vision aids, such as large-print items and special video systems, to help you cope with reduced eyesight. Support groups and Counselling can also help you deal with vision loss.
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The exact cause of glaucoma isn't known. Experts think that increased pressure in the eye (intraocular pressure) may cause the nerve damage in many cases. But some people who have glaucoma have normal eye pressure.
Get more information on eye anatomy and function.
In open-angle glaucoma (OAG), fluid in the eye (aqueous humour) doesn't drain well. When this happens, the fluid builds up. This buildup increases the intraocular pressure (IOP) and may damage the optic nerve.
Up to half of the people with OAG don't have higher-than-normal IOP. This is called normal- or low-tension glaucoma.
In closed-angle glaucoma (CAG), fluid can't drain because the drainage angle is blocked. This may occur when:
Glaucoma that is present at birth (congenital glaucoma) or that develops in the first few years of life (infantile glaucoma) is often caused by certain birth defects. A birth defect may occur because of an infection in the mother during pregnancy, such as rubella, or because of an inherited condition such as neurofibromatosis.
Some people get glaucoma after an eye injury or after eye surgery. A cataract and some medicines (corticosteroids) that are used to treat other diseases may also cause glaucoma. Glaucoma caused in these ways is called secondary glaucoma.
Symptoms of glaucoma vary according to the type of glaucoma you have.
Most people with OAG have no symptoms when they are diagnosed. You may have some side vision loss, but you may not notice it until the vision loss becomes severe. This is because the less affected eye makes up for your vision loss. The loss of sharpness of vision (visual acuity) may not become apparent until late in the disease. By that time, significant vision loss has occurred.
may cause no symptoms. Or symptoms may range from mild to severe. They usually affect only one eye at a time.
Severe symptoms may include:
You may have short episodes of symptoms that usually occur in the evening and are over by morning. This is called subacute closed-angle glaucoma. CAG can also happen suddenly and require medical attention right away.
Symptoms of glaucoma present at birth (congenital glaucoma) and glaucoma that develops in the first few years of life (infantile glaucoma) may include:
Your baby may rub his or her eyes, squint, or keep the eyes closed much of the time.
Glaucoma usually affects side (peripheral) vision first. If glaucoma isn't treated, vision loss will continue, causing total blindness over time. If glaucoma is found early and treatment starts right away, good eyesight can usually be maintained.
Treatment for any type of glaucoma may delay or prevent further vision loss. But treatment can't reverse vision loss that has already occurred. In a few rare cases of congenital glaucoma, treatment has reversed some damage to the optic nerve.
How much your life will be affected depends on your lifestyle and on how bad your vision loss is. Normal use of your eyes (such as for reading or watching TV) won't speed up vision loss or make the condition worse. For information on how to live with low vision, see Home Treatment.
OAG usually affects both eyes at the same time. But one eye may be affected more than the other.
Vision changes so slowly that much of your eyesight may be affected before you notice the condition. Blind spots from each side of the field of vision gradually meet, increasing the area of blindness. Central vision, used for reading and seeing details, is affected last.
CAG usually affects only one eye at a time. It can happen suddenly (acute) or be a long-term problem. If it's acute, it's an emergency. Severe and permanent vision loss can develop within hours or days after symptoms start.
You may have short episodes of CAG. Without treatment, these episodes will keep coming back. They can become an emergency situation (acute closed-angle glaucoma) or a long-term problem (chronic closed-angle glaucoma).
may be present at birth or develop within the first few years of life. Treatment needs to start right away to help avoid further vision loss and blindness. In certain children, some of the optic nerve damage caused by the disease can be reversed with treatment.
Risk factors for OAG include:
Risk factors for CAG include:
Risk factors for congenital glaucoma include:
or other emergency services immediately if you have:
Call your doctor if you:
Your family doctor or general practitioner can refer you to an ophthalmologist who can diagnose glaucoma.
An optometrist can screen for glaucoma but will refer you to an ophthalmologist to diagnose and treat the disease.
An optician cannot diagnose or treat glaucoma.
Early detection and treatment of glaucoma are important for controlling the condition and preventing blindness.
A doctor evaluating possible glaucoma will take a medical history and do a physical examination. If your doctor suspects glaucoma, he or she will refer you to an eye specialist (ophthalmologist).
The eye specialist will check your eyes to help find out if you have the disease and how severe it is. He or she will look for certain signs of damage in the eye by checking things like:
After glaucoma is diagnosed, eye examinations are done on a regular basis to monitor the disease.
Your doctor may also do a low-vision evaluation to help find ways you can make the most of your remaining vision and maintain your quality of life.
If you are younger than 40 and have no known risk factors for glaucoma, the Canadian Ophthalmological Society (COS) recommends that you have a complete eye examination every 10 years. This includes tests that check for glaucoma.footnote 2 The COS suggests more frequent routine eye examinations as you age, even if you aren't at increased risk for glaucoma.
The COS also suggests that people who are at risk for glaucoma have complete eye examinations according to the schedule below:
After reviewing all of the research, the Canadian Task Force on the Periodic Health Examination (CTFPHE) has not recommended for or against routine glaucoma screening for all adults.
Most treatment for glaucoma is aimed at lowering the pressure in the eyes (intraocular pressure, or IOP). This helps save your eyesight by slowing the damage to the optic nerve. In adults, treatment can't restore eyesight that has already been lost as a result of glaucoma. But in certain children, some of the damage caused by congenital glaucoma can be reversed.
Treatment options include medicines and surgery, including laser surgery. The risks and benefits of these options differ depending on the type of glaucoma and other factors.
It is important to understand that treatment for glaucoma will most likely continue for the rest of your life. You will need regular eye examinations by an eye doctor. Ask your doctor about the best treatment for your particular condition.
Though glaucoma can lead to a significant loss of vision, your doctor can refer you to counsellors who specialize in helping people adjust to living with low vision.
The eye doctor sets a target eye pressure for each eye and will check it regularly. If the pressure is high enough, or if the doctor sees signs of damage caused by glaucoma, the doctor may advise that you start taking medicine, change the medicine you take, or think about having surgery.
Treatment for OAG usually starts with medicines (most likely eyedrops) to lower the pressure inside the eye. If medicines don't work, your doctor may use laser treatment or surgery. In some cases, laser treatment or surgery will be tried before medicine.
Initial treatment for CAG is usually a procedure called laser iridotomy. You may also need medicine (usually eyedrops) to help you stay at your target eye pressure.
If the pressure in your eye stays high or if damage to the optic nerve gets worse despite treatment, your doctor will adjust your treatment. In some cases, your doctor may need to adjust your medicines. Or, if you haven't had the laser procedure, you may need this or another surgery.
Acute closed-angle glaucoma
CAG can be an emergency situation (acute closed-angle glaucoma). Blockage of fluid in the eye causes a sudden increase in pressure, causing rapid damage to the optic nerve.
Acute closed-angle glaucoma usually causes significant pain. Laser treatment is needed right away for this problem.
If you have had a case of acute closed-angle glaucoma, your ophthalmologist may talk with you about having cataract surgery. It may be discussed even if you don't have a cataract that's bothering you right now. You can talk with your doctor about the pros and cons of each option to lower your risk of future problems with closed-angle glaucoma.
almost always requires surgery to lower eye pressure. Medicine may sometimes be used, but it usually doesn't work as well.
Because glaucoma can't be cured and treatment doesn't always prevent further loss of vision, people may try alternative unproven treatment methods, such as acupuncture or marijuana. But most of these alternative treatments either haven't been studied or haven't been proved to work for glaucoma. Such treatments may be expensive. And some can be hazardous to your health.
To learn more, see Home Treatment, Medications, and Surgery.
Most of the risk factors (such as age, race, and family history) for glaucoma are beyond your control. Whether or not you are at increased risk for glaucoma, it's best to get routine eye examinations and tests as your eye doctor suggests. Finding and treating glaucoma early is important to help prevent blindness.
If you have high pressure in your eyes but you don't have glaucoma, your eye doctor may suggest treatment that helps lower your eye pressure. This may help delay or prevent the onset of glaucoma.
Glaucoma can affect your life. How much you are affected depends on how bad your vision loss is, what kinds of activities you do, and your lifestyle. You can work with your doctor to find ways to make the best use of your remaining vision. You can:
It's common to feel sad or angry when you learn that you have glaucoma. Try building a support group of family and friends. Your doctor can also refer you to counsellors who specialize in helping people adjust to living with low vision.
Medicine is a large part of your treatment. Be sure to:
Prescription medicines to lower the pressure inside the eye (intraocular pressure, or IOP) are used to treat all types of glaucoma. They work either by reducing the amount of fluid (aqueous humour) that is produced by the eye or by increasing the amount of fluid that drains out of the eye. These medicines may be given as eyedrops, as pills, in liquid form by mouth, or through a vein (in emergency situations). In most cases, eyedrops are used first.
In congenital glaucoma, medicines may be used to decrease the pressure in the eyes and reduce the cloudiness of the clear front surface (cornea) of the child's eye. Medicines are usually only used until surgery can be done.
When glaucoma has already caused vision loss, further vision loss may occur even after the pressure in the eye is lowered to the normal range with medicine. Talk to your doctor about the goals of treatment, how long the medicine will be tried, and the possible side effects. Eye medicines can cause symptoms throughout the body.
You will need follow-up visits with your doctor to find out whether your medicine is working as well as it should. You can also discuss any side effects or medicine schedule problems.
In most cases, medicines used to treat glaucoma must be continued daily for the rest of your life.
Medicines that decrease the amount of fluid produced by the eye include:
Medicines thatincrease the amount of fluid that drains out of the eye include:
Some medicines have two different medicines mixed into one bottle.
Surgery reduces the pressure in the eyes by opening blocked drainage angles or creating a new opening that fluid can flow through to leave the eye. In some cases surgery may be done to relieve pain caused by glaucoma.
Doctors can use either a surgical cutting tool or a very focused beam of light, called a laser, to do surgery for glaucoma. Laser surgery is usually the first type of surgery tried. If laser surgery doesn't help, your doctor may try conventional surgery.
It is not unusual for some people to have both open- and closed-angle glaucoma. They may need more than one kind of procedure.
There are three basic types of surgery for glaucoma in adults.
Surgery to increase drainage of fluid from the eye
This type of surgery involves making a trapdoor that allows fluid to drain from the eye. Examples of this type of surgery include the following:
Surgery to prevent closure of the drainage angle
These procedures involve making a new opening in the coloured part of the eye (iris) that allows fluid to flow through the eye. They are used to treat sudden (acute) and long-term closed-angle glaucoma. The procedures also will prevent closed-angle glaucoma in people who have narrow drainage angles.
Laser iridotomy can usually be done instead of surgical iridectomy. But some people with complicated or severe glaucoma may need to have surgical iridectomy.
Surgery to decrease the amount of fluid produced in the eye
When other surgery fails to improve the flow of fluid from the eye, procedures to destroy the part of the eye that produces fluid (ciliary body) can be done. These procedures are also used when scar tissue has formed after a previous surgery.
For congenital glaucoma, there are two slightly different procedures that both attempt to open the drainage angle directly. They are equally successful in children, but they are not used for adults. If these procedures fail in a child, then trabeculectomy or tube-shunt surgery may be tried.
Deciding whether to have surgery is difficult because:
As with any other surgery, you and your doctor should make the decision to operate based on the risks and benefits of having the surgery. One thing to consider is which eye should be operated on first. There may be other questions about glaucoma surgery that you should discuss with your doctor before making a decision.
Cataracts may occur in people who also have glaucoma. This commonly occurs in older people. Surgery to remove the cataract may be done at the same time as surgery for glaucoma. If surgeries for glaucoma and a cataract are done at the same time, you may notice improved eyesight after surgery.
American Academy of Ophthalmology (2010). Primary Angle Closure (Preferred Practice Pattern). San Francisco: American Academy of Ophthalmology. Also available online: http://aao.org/ppp.
Canadian Ophthalmological Society (2007). Canadian Ophthalmological Society evidence-based clinical practice guidelines for the periodic eye examination in adults in Canada. Canadian Journal of Ophthalmology, 42: 39–45. Also available online: http://www.eyesite.ca/resources/CPGs/COSVisionScreeningCPGEng_Feb07.pdf.
Other Works Consulted
American Academy of Ophthalmology (2007). Vision Rehabilitation for Adults (Preferred Practice Pattern). San Francisco: American Academy of Ophthalmology. Available online: http://one.aao.org/CE/PracticeGuidelines/PPP.aspx.
Salmon JF (2011). Glaucoma. In P Riordan-Eva, ET Cunningham, eds., Vaughan and Asbury's General Ophthalmology, 18th ed., pp. 222–237. New York: McGraw-Hill.
Trobe JD (2006). The red eye. Physician's Guide to Eye Care, 3rd ed., chap. 4, pp. 47–51. San Francisco: American Academy of Ophthalmology.
Vass C, et al. (2007). Medical interventions for primary open angle glaucoma and ocular hypertension. Cochrane Database of Systematic Reviews (4).
ByHealthwise StaffPrimary Medical ReviewerAdam Husney, MD - Family MedicineE. Gregory Thompson, MD - Internal MedicineChristopher Joseph Rudnisky, MD, MPH, FRCSC - Ophthalmology
Current as ofDecember 3, 2017
Current as of: December 3, 2017
Adam Husney, MD - Family Medicine
& E. Gregory Thompson, MD - Internal Medicine & Christopher Joseph Rudnisky, MD, MPH, FRCSC - Ophthalmology
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