Glaucoma

Your eye needs a certain amount of pressure to keep the eye healthy and in the right shape. But if the pressure is too high, it can cause your optic nerve to become damaged at the point where it leaves your eye. This damage is called glaucoma. Your optic nerve is important for sight because it carries the signals from your eye to your brain to allow you to “see” the world around you.

It's also possible to develop glaucoma even when eye pressure is within the normal range. This can be because the optic nerve is more fragile or sensitive than usual.

This page contains a summary of our information on glaucoma. To read our full information, download our understanding glaucoma booklet, which is accredited by the Royal College of Ophthalmologists:

If there is damage to your optic nerve, blind spots can begin to form in your vision. Sight loss usually affects your side (peripheral) vision first. Often there are no symptoms unless the condition is advanced.

Without treatment, glaucoma can cause:

• Difficulty seeing contrast. It may be harder to see objects that are similar in colour to their background.
• Poor night vision. You might find it difficult to see or get around in dim light.
• Reduced side vision. You may miss things in your side vision.
• Finally, if left untreated, your central vision may be affected too, causing blind spots to appear when you look straight ahead.

If glaucoma is not treated or is poorly controlled, it can eventually lead to complete loss of sight (blindness). However, with treatment, most people with glaucoma keep good vision for life.

Once sight loss occurs, it can’t be reversed. There are currently no treatments which can repair the damaged nerve. This means that it’s vital to detect and treat glaucoma early to prevent optic nerve damage in the first place and to avoid sight loss.

Primary glaucoma

Primary of glaucoma occurs on its own, without a known cause and isn't caused by any other eye condition.

• Primary open angle glaucoma where damage to the optic nerve occurs slowly over a long period of time due to your eye pressure increasing to more than 21mmHg. This is the most common type of glaucoma.
• Normal tension glaucoma when an eye pressure of less than 21mmHg still causes damage to the optic nerve.
• Primary closed angle glaucoma is when the angle, where the aqueous fluid drains from the eye, narrows or closes. It can be chronic (gradual onset) or acute (where the eye pressure rises to a very high level, very suddenly). You can read more about closed angle glaucoma by downloading our booklet.

Secondary glaucoma

Secondary glaucoma because of another eye condition, an eye injury, or medication.

Childhood glaucoma

Glaucoma which affects babies and children is rare. It can happen when the aqueous drainage system hasn’t developed properly before birth, or because of another eye condition or problem with eye development.

Primary open angle glaucoma is the most common type of glaucoma in the UK. It’s also known as chronic open angle glaucoma which means the damage to your optic nerve and changes to your sight happen very slowly over time.

What are the symptoms of open angle glaucoma?

You can’t ‘feel’ primary open angle glaucoma. It doesn’t cause any symptoms and the eye pressure doesn’t cause any pain. You may not notice any changes to your vision because glaucoma affects your peripheral vision (side vision) first. Your peripheral vision is less sensitive than your central vision, making it harder to notice early changes. As a result, your vision can be gradually damaged without you being aware of it.

Because you may not notice a problem until your glaucoma is more advanced, it’s important to have regular eye examinations as this is the only way to know if you have it. Your optometrist will let you know how often you need to have an eye test based on your age, family history and other risk factors. The earlier your glaucoma is picked up and treated, the more your sight can be protected.

Primary open angle glaucoma usually affects both eyes, but one eye may be affected more than the other.

What is the treatment for primary open angle glaucoma?

Because you may not notice a problem until your glaucoma is more advanced, it’s important to have regular eye examinations as this is the only way to know if you have it. Your optometrist will let you know how often you need to have an eye test based on your age, family history and other risk factors. The earlier your glaucoma is picked up and treated, the more your sight can be protected.

Damage to the optic nerve can occur at different eye pressures among different people. Even if your eye pressure is at a normal level to begin with, treatment will still be aimed at lowering this pressure to a level which is safe for you – this may be called your ‘target eye pressure’.

Your eyecare professional will explain your treatment options. If you need help deciding about treatment for open angle glaucoma, the NHS provides a decision support tool.

You can read more about these treatments by downloading our booklet.

Eye drops

Eye drops are the most common treatment for glaucoma. For many people with glaucoma, this is all the treatment they will ever need. But these drops will need to be used long term or for life.

There are different types of eye drops for glaucoma. They all reduce the amount of aqueous fluid in the eye. This lowers eye pressure and so reduces damage to the optic nerve. The eye drops work by either reducing the amount of aqueous fluid that your eye makes, or by helping the aqueous fluid drain away better.

The type of eye drops that you’ll be prescribed will depend on your individual medical history. Your eye pressure will be monitored at regular check-ups to make sure the drops are working.

It may take time to find the right drop or combination of drops to control your eye pressure. If you’ve just started using eye drops, or if you have recently changed your type of eye drops, your eye pressure would normally be checked within a few months of starting the new drops to find out how well they’re working.

Taking the drops will not cause any change in your sight, so it can be difficult to understand why you need to put them in every day. Your drops are preventing any future damage to your sight so it’s very important to keep using them. If you don’t use your drops then your eye pressure will remain too high and damage your optic nerve, which will cause you to lose your sight.

SLT laser treatment

When you are first diagnosed with primary open angle glaucoma, laser treatment is now usually offered as the first treatment option. You may be given eye drops to use short term to control your eye pressure while waiting for the procedure.

Laser treatment may also be recommended if you have been using eye drops for some time, but your eye pressure is still not well controlled.

SLT may lower your eye pressure enough by itself, or you may need eye drops as well. If you need eye drops, you may need fewer than you’d have needed without SLT, or you may not need them as soon.

You may need to have SLT repeated if it works well to start with, but the effect wears off over time.

If you choose not to have SLT, or if you’re told SLT is not suitable for you, you’ll be prescribed eye drops to control your eye pressure.

Surgery

Most people with glaucoma will not need surgery. It is usually considered in a small number of people, where eye drops or laser treatments have not worked in controlling the eye pressure, or when glaucoma is advanced.

If surgery is recommended, your ophthalmologist will explain the surgery options that are suitable for you and the risks and benefits of surgery. Ask them any questions or concerns you have about surgery.

This type of glaucoma occurs when your eye pressure is within normal range but causes damage to your optic nerve.

It’s not entirely known why some people’s optic nerve becomes damaged even though their eye pressure is at a normal level. It’s thought that perhaps some people’s optic nerve may just be weaker or have a more fragile blood supply and be unable to cope with an eye pressure within the normal range.

Normal tension glaucoma is treated in the same way as open angle glaucoma – by lowering your eye pressure to a level which is right for you, to protect your sight. You can read about these treatments by downloading our booklet.

Some people naturally have eye pressure above the normal range, but this pressure doesn’t cause any damage to their optic nerve. This is described as ocular hypertension rather than glaucoma.

Different people can have different optic nerve strengths, and some people’s optic nerves stay healthy at higher than normal eye pressures.

If you have ocular hypertension, it can increase your risk of developing glaucoma, so this needs to be monitored. Sometimes you may be prescribed eye drops or offered laser treatment to help reduce your eye pressure and reduce your risk of developing glaucoma. If this is the case, you’ll be followed up at the eye clinic regularly to monitor your eye pressure. You may be discharged from the eye clinic if you don’t require eye drops and tests show that there is no sign of glaucoma. However, it’s important for you to visit your optometrist (optician) regularly for your eyes to be checked so that any future changes can be picked up.

Most people with glaucoma will retain good vision with the right treatment if it is detected early. Having glaucoma may mean you need to make a few changes to your everyday life to prevent sight loss. For many people, this includes using eye drops daily and for most people having to attend regular eye clinic visits.

Keeping to your treatment

The most important thing you can do to protect your sight is to keep to the treatment that has been recommended for you. For many people with glaucoma, this involves putting in eye drops daily for life. It’s important to remember to use your drops regularly as prescribed, to prevent glaucoma from getting worse and causing damage to your sight.

When you’re first prescribed eye drops, you should be given instructions on:

• how to put them in correctly
• how many times a day you need to use them and when
• how to store them
• what aids are available which may make putting the drops in easier
• if you are prescribed more than one drop, how long to leave in between each type of drop.

There are different techniques that you can use to instil your drops. Some helpful guides:

• Easy read: Putting in your eye drops | Glaucoma UKglaucoma.uk/product/booklet-easy-read-putting-in-your-eye-drops/
• How to use your eye drops - Moorfields Eye Hospital www.moorfields.nhs.uk/for-patients/information-hub/how-to-use-your-eye-drops

After putting in your eye drops, gently close your eye. With a finger, press lightly on the corner of your eye near your nose for a couple of minutes. This blocks your tear duct and helps keep the eye drop in your eye where it’s needed. If you’re not sure whether the drop has gone into your eye, it’s ok to put another one in. If you use more than one type of glaucoma drop, you’ll usually be advised to leave around 5 minutes between each one. If you use glaucoma drops and dry eye drops, wait around 15 minutes between each one.

Contact your eye clinic as soon as you can if your eye drops are causing you any problems. Side effects can include eye irritation, change in iris colour, or redness, and some drops aren’t suitable for people with certain underlying health conditions. Preservative-free drops may be an option if you’re sensitive to any of the preservatives added to the drops. You can also ask about using lubricating eye drops, ointments or gels to keep your eyes feeling comfortable. The risk of side effects is very small compared to the risk of losing your sight if you don’t use the drops. You should keep using your eye drops unless told to stop by your eyecare professional.

Dry eye is very common in people taking glaucoma drops. More information about managing dry eye can be found in our booklet Understanding Dry eye.

If you struggle to squeeze the bottle or aim the drops accurately, there are lots of aids that can help. Some aids help to hold the bottle steady above your eye; others can help make squeezing the bottle easier. Speak to a healthcare professional such as an ophthalmologist, GP, nurse, pharmacist or optometrist about which aids suit your prescribed bottle.

You can use the Patient Eye Drop Assessment form to record how you use your drops and note any concerns. Take it to your appointment so your eyecare professional can answer your questions.

Attending your appointments

It’s very important to attend all your appointments to make sure your eye pressure stays stable. Changes in eye pressure have no symptoms, so regular checks are the only way to confirm your treatment is working. It also gives you a good opportunity to ask your eyecare professional any questions you may have about your glaucoma treatment.

Depending on where you live and how stable your glaucoma is, you may be seen at a hospital eye clinic or by a specialist eyecare professional in the community.

How often you need to be seen depends on how well your treatment is working. At your appointment, ask your eyecare professional when they recommend your next check-up should be. The timing can vary. For example, if you’ve just started new eye drops, they may want to see you sooner to check how well they’re working. If your glaucoma is stable, your appointments might be further apart. Note the suggested timeframe and if you don’t get an appointment within it, contact your eye clinic to follow up.

At your regular follow up appointments, you will usually repeat many of the tests that were done when you were first diagnosed. These tests help check if your glaucoma has changed since your last visit. Tests may be carried out by a specialist optometrist, ophthalmic technician or an ophthalmologist. The results will then be reviewed by the ophthalmologist or eyecare professional who will discuss them with you, either in person or remotely and let you know if any changes to your treatment are needed.

Making things easier to see

If you do have some sight loss, there are lots of things you can do to make the most of your sight. This may mean making things bigger, using brighter lighting, or using colour to make things easier to see. Ask your eye clinic or optometrist about having a low vision assessment. You can also find out tips for making the most of your sight by downloading our booklet:

Connecting with others and support for your eye condition

Sometimes, it can help to connect to people with the same eye condition.

Glaucoma UK provides help, information and support to anyone affected by glaucoma including a helpline, support groups and a buddy scheme. Find out more about the many ways they can support you at every stage of your glaucoma journey.