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This factsheet is for people who have glaucoma, or who would like information about it.

Glaucoma is the name for a group of eye conditions where your optic nerve is damaged and vision deteriorates.

If you have glaucoma, your optic nerve (the nerve that connects your eye to your brain) is damaged at the point where it leaves your eye.

Sometimes this can be the result of an increase in pressure in your eye, which usually happens when fluid (the aqueous humour) in the front part of your eye (the anterior chamber) doesn't drain away properly. Usually the amount of fluid produced in your eye is balanced by the amount draining away, so the pressure in the front part of your eye remains controlled. If you have glaucoma, the pressure within your eye can be so high that your optic nerve is damaged and you may begin to lose your sight.

Glaucoma can also result from a weakness in your optic nerve, which can lead to damage even when the pressure in your eye appears to be normal. In most people, glaucoma is caused by both high pressure and a weakness in the optic nerve to varying extents.

Glaucoma can affect both of your eyes, but one eye may be affected more than the other. If you get treatment early, it can prevent further sight loss.

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Image showing a side view of the different parts of the eye


  • Types Types of glaucoma

    Chronic open angle glaucoma

    Chronic open angle glaucoma (also called primary open angle glaucoma) is the most common type. It develops very slowly and damage to your nerve and eyesight happens gradually.

    You can get chronic glaucoma if the drainage channels (through which fluid in your eye flows) become blocked as this can slowly raise the pressure within your eye.

    Normal tension glaucoma

    A form of chronic glaucoma called normal tension glaucoma can occur even if the pressure in your eye is within the normal range, which is usually less than 22 millimetre of mercury (mm Hg). It's thought that the optic nerve may have a poor blood supply or a weakness.

    Acute angle-closure glaucoma

    This type of glaucoma happens when the pressure in your eye rises very quickly. The drainage angle that lies between the cornea (the clear window at the front of your eye) and the iris (the part that gives your eye its colour) narrows suddenly. This prevents fluid in your eye from flowing out of your eye.

    Acute glaucoma can be very painful and you must seek urgent medical attention. It can cause permanent blindness unless treated quickly.

    Secondary glaucoma

    If you have other eye conditions, such as an injury to your eye or repeated inflammation, you can get secondary glaucoma. If you have diabetes, you may be at risk of developing a type of secondary glaucoma called rubeotic glaucoma.

    Congenital glaucoma

    This is a very rare condition where a baby is born with glaucoma. The tissues at the angle of the anterior chamber don’t develop properly and this slows the flow of the fluid out of the eye.

  • Symptoms Symptoms of glaucoma

    If you have chronic open angle or secondary glaucoma, you probably won't notice any symptoms until your sight has deteriorated considerably. This is because the first part of your sight to be affected is the outer or peripheral field of vision. Your central vision, which you use to focus on objects, isn't usually affected until much later.

    Acute glaucoma tends to come on very quickly and symptoms include:

    • loss of sight
    • pain in your eye
    • a headache
    • blurred vision or a halo around lights
    • feeling sick or vomiting
    • redness in the white of your eye

    If you think you're having an attack of acute glaucoma, you must seek urgent medical attention.

    It can be difficult to recognise symptoms of congenital glaucoma but if your baby has watering eyes, is very sensitive to light or has cloudy, white, enlarged eyes, make an appointment to see your GP.

  • Diagnosis Diagnosis of glaucoma

    You may not have any symptoms until you start to lose your sight. Therefore, screening tests are important to detect glaucoma. An optometrist – a registered health professional who examines eyes, tests sight and dispenses glasses and contact lenses – can do these during a routine eye test.

    As glaucoma is more common if you're over 40, it's important to have an eye test at least every two years from this age onwards. It's also important to be tested regularly if you're at risk of developing glaucoma, for example if a family member has it or you have diabetes.

    An eye test usually takes about 30 minutes and includes a number of tests for glaucoma. Your optometrist may:

    • look at your optic nerve by shining a light from a torch instrument into your eye
    • look at the thickness of your cornea
    • measure the pressure in your eye using a tonometry test – a small amount of pressure is applied to your eye using a tiny tool or a warm puff of air
    • measure your field of vision in a perimetry test by showing you a sequence of spots of light on a screen and asking you which ones you can see

    If your optometrist thinks you may have glaucoma, he or she will refer you to an ophthalmologist (a doctor who specialises in eye health, including eye surgery) for more tests. These may include a test to examine the area in your eye where the fluid drains out.

  • Treatment Treatment of glaucoma

    Treatment for glaucoma aims to lower the pressure inside your eye to reduce your risk of losing your sight or prevent any further loss of sight. Treatment can't reverse any existing optic nerve damage, so it won't improve your sight if it has already deteriorated.


    Eye drops to treat glaucoma include:

    • prostaglandin analogues that help your eye's internal fluid drain out more quickly
    • beta-blockers that reduce the pressure in your eye – they slow down the build-up of fluid by reducing the production of it
    • carbonic anhydrase inhibitors that lower pressure in your eye by reducing fluid build-up
    • sympathomimetics that reduce pressure in your eye and help the fluid build-up to drain away

    Several other types of medicine are available as alternatives or in addition to prostaglandins or beta-blockers. It's important that you follow your ophthalmologist’s advice and use the medicines as he or she advises to ensure the treatment is effective. If you don't, the pressure in your eye will rise again.

    If you think your medicine is causing a side-effect, speak to your ophthalmologist as soon as possible. He or she can advise you and if necessary, prescribe alternative eye drops or consider other treatments.

    Always ask your doctor for advice and read the patient information leaflet that comes with your medicine.


    There are a range of operations to treat glaucoma. The operation you have will depend on the type of glaucoma you have and how severe it is – ask your ophthalmologist which is best for you.

    Laser treatment

    Laser treatment uses a laser to open the holes in the draining system in your eye to help fluid drain out or to stop your eye producing as much fluid. Laser treatment may also be used to make a small hole in your iris if you are at increased risk of or have acute angle closure glaucoma. This allows fluid in your eye to circulate and may open the angle to reduce the risk of it closing.

    Laser treatment is usually quick and causes little discomfort. It can be done under local anaesthesia and you will be able to go home the same day. The success of this type of treatment varies from person to person, and you may need to continue using eye drops after treatment.

    Trabeculectomy surgery

    You may need surgery if medicines and/or laser treatment haven't lowered the pressure in your eye.

    There are a range of operations; the most commonly performed is trabeculectomy. In this operation a tiny opening is created in your eye wall to allow fluid to escape under the thin lining of the white of your eye (the conjunctiva) and be absorbed back into your bloodstream. You may have the operation under local or general anaesthesia – ask your surgeon for advice.

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  • Causes Causes of glaucoma

    Glaucoma is caused by an increase in pressure within your eye or a weakness in the optic nerve, or both.

    You're more likely to get glaucoma later in life. For example, chronic open angle glaucoma is uncommon in people under 40, but it affects one in a 100 people aged over 40 and around five in a 100 people over 65.

    Other factors that can increase your chances of getting glaucoma include:

    • ethnicity – if you're of African or black Caribbean origin, you're more at risk of getting chronic open angle glaucoma and it may affect you earlier in life and be more severe, while if you’re of Asian descent, you’re more likely to get acute angle-closure glaucoma
    • a family history of glaucoma
    • being very short-sighted
    • diabetes
  • Prevention Prevention of glaucoma

    If you're over 40, it's important to have an eye test every two years to check for the early signs of glaucoma. If one of your parents, children, brother or sister has glaucoma, have an eye test every year.

  • FAQs FAQs

    Can I drive if I have glaucoma?


    You should still be able to drive if your glaucoma is still in the early stages, but you’re required by law to report a condition that might affect your eyesight.


    If you’re diagnosed with glaucoma in both eyes you will need to report it to the Driver and Vehicle Licensing Authority (DVLA). However, if glaucoma affects only one of your eyes you don’t need to tell the DVLA, provided you don’t have any other medical condition in your other eye.

    When you inform the DVLA that you have glaucoma you will be asked to fill out a detailed medical questionnaire to provide specific details about your condition. You will also be asked to give your consent for a DVLA medical adviser to request medical information from your ophthalmologist or optometrist. The DVLA may contact him or her or arrange for you to be examined by a locally appointed specialist or to have an eyesight test.

    The DVLA will ask you to have regular tests to assess if it’s safe for you to drive – in particular you will be tested on your peripheral vision. If you fail to meet the DVLA’s standards you will not be able to drive again.

    Ask your optometrist or ophthalmologist for advice about if you can drive and any tests you may need to have.

    If I have glaucoma, does it help to follow a particular diet?


    No, there is no evidence that following a particular diet helps to treat or prevent glaucoma.


    Many claims have been made about following different diets and taking various supplements to treat glaucoma. However, there is little, if any, scientific evidence to back up these claims.

    In the main, we should all aim to eat a balanced diet that's low in saturated fat, sugar and salt, and high in fibre, vegetables (including dark leafy greens like spinach and kale) and fruit.

    What if I forget to put in my eye drops for glaucoma?


    If you forget a dose, put in your eye drops as soon as you remember.


    It isn't a problem if you forget to use your eye drops on the odd occasion. However, it's important to get into a routine of using your eye drops at around the same time every day to help you remember.

    Try using a chart with tick boxes to keep a check on whether you have taken your eye drops every day. You could also set a timer to ring at a particular time to remind you when you need to put them in.

    Using your drops regularly, as advised by your doctor, offers the best protection against glaucoma and will prevent it getting worse. Although you will not notice any difference to your vision from using the eye drops, they will prevent you losing your sight.

    Why should I register as blind or partially sighted if I have glaucoma?


    If you have glaucoma, you may be eligible to register as being blind or partially sighted, which can make it easier to get practical help. There may also be financial benefits.


    If your glaucoma has reached a stage where your vision has been severely affected, you may be eligible to register with your local council as blind or partially sighted. You don't have to register but doing so can help you to get any support you need.

    It's important to realise that being registered doesn't mean you have lost or will lose your sight completely. It just records that your level of vision is such that you may require assistance in certain areas and will allow you to access these facilities more readily.

    To find out whether you're eligible for registration, you will need to see an ophthalmologist, a doctor who specialises in eye health (including eye surgery). He or she will assess you by carrying out some eye tests, and if necessary, give you a certificate of vision impairment. With your agreement, this will be sent to your local social services department.

    Your social services department will then contact you to find out what help you may need. They may be able to offer you services such as:

    • practical help in your home, for example, cleaning and cooking
    • help with developing skills to remain independent
    • modifications to your home
    • transport services

    The amount of support that is available varies so ask your local council for more information.

    Will I know if my glaucoma treatment is working as I don’t have symptoms?


    Your ophthalmologist or optometrist will closely monitor your condition to check if your treatment is working and for any further damage to your eyesight.


    If you use eye drops to treat glaucoma, it's important that you follow your ophthalmologist’s advice and use your medicine as he or she advises to ensure the treatment is effective. If you don't, the pressure in your eyes will rise again.

    When you’re diagnosed with glaucoma you may need to visit your ophthalmologist frequently to start with (about every one to four months) so he or she can check if your treatment is working and your eye pressure is stable. If your treatment works and your eye pressure remains stable – and you don’t have any major side-effects from your treatment – you will be asked to have check-ups less often, about every six to 24 months, depending on your condition.

    As you don’t have symptoms of glaucoma, it’s important to attend these appointments to check your treatment is working. If it isn’t effective, the pressure in your eye may rise and you could permanently lose more of your sight.

    When you visit your optometrist or ophthalmologist, he or she will measure the inner pressure of your eyes in a tonometry test using a tool called a tonometer. This involves applying a small amount of pressure to your eye using a tiny tool or a warm puff of air.

    He or she will also test your visual field in a perimetry test. You will be asked to look straight ahead and then indicate when a moving light passes your peripheral (or side) vision.

    Your optometrist or ophthalmologist will also examine the back of your eye. He or she will use drops to dilate your pupil when doing this – these can affect your eyesight so you will need to arrange for someone to drive you home.

    The tests to monitor your glaucoma are more detailed than those used in a routine eye test by an optometrist. Ask your optometrist or ophthalmologist for more information about the tests and for advice on how often you should be monitored.

  • Resources Resources

    Further information


    • Sena DF, Ramchand K, Lindsley K. Neuroprotection for treatment of glaucoma in adults. Cochrane Database of Systematic Reviews 2010, Issue 2. doi:10.1002/14651858.CD006539.
    • Glaucoma. Royal National Institute of Blind People., published 8 June 2011
    • Glaucoma: diagnosis and management of chronic open angle glaucoma and ocular hypertension. National Institute for Health and Clinical Excellence (NICE), April 2009.
    • Facts about glaucoma. National Eye Institute., published September 2009
    • Glaucoma and ocular hypertension. Prodigy., published September 2010
    • Primary open-angle glaucoma. eMedicine., published 20 May 2011
    • Five common glaucoma tests. Glaucoma Research Foundation., published 16 May 2011
    • Acute angle-closure glaucoma. eMedicine., published 10 November 2010
    • Neovascular glaucoma. eMedicine., published 9 March 2011
    • Visiting an optician. Royal National Institute of Blind People., published 21 October 2010
    • Joint Formulary Committee. British National Formulary. 62nd ed. London: British Medical Association and Royal Pharmaceutical Society of Great Britain; 2011
    • Gray TA, Orton LC, Henson D, et al. Interventions for improving adherence to ocular hypotensive therapy. Cochrane Database of Systematic Reviews 2009, Issue 2. doi:10.1002/14651858.CD006132.pub2
    • Registering your sight loss. Royal National Institute of Blind People., published 13 January 2011
    • Special diets for ocular hypertension (OHT) and chronic open angle glaucoma (COAG). NHS Evidence., published 23 February 2011
    • A feast for your eyes. The College of Optometrists., published 12 July 2011
    • Glaucoma and driving. Direct.Gov., accessed 14 July 2011
    • What happens after you have told DVLA about your health condition. Driver and Vehicle Licensing Agency., accessed 14 July 2011
    • For medical practitioners: At a glance guide to the current medical standards of fitness to drive. Driver and Vehicle Licensing Agency, February 2011.
  • Related information Related information

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    Produced by Kerry McKeagney, Bupa's Health Information Team, February 2012.

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