Trabeculectomy Surgery

Patient Experience

  • Reference Number: HEY-416/2021
  • Departments: Ophthalmology Department
  • Last Updated: 16 September 2021


This leaflet has been produced to give you general information about your trabeculectomy surgery for glaucoma.  Most of your questions should be answered by this leaflet.  It is not intended to replace the discussion between you and the healthcare team, but may act as a starting point for discussion.   If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team.

What is a Trabeculectomy?

A trabeculectomy is an operation for glaucoma. The operation is normally done under local anaesthetic (an injection beside the eye). The operation is done to the white of the eye under the eyelid. We make a small trapdoor flap in the white of the eye, under which we cut a little hole to allow fluid to drain out of the eye.  This trapdoor flap is then sewn up with some loose stitches.  This should allow the fluid to continue to drain out slowly, so that the eye pressure is reduced.  Some more stitches are then put on the conjunctiva (the thin ‘skin’ covering the eyeball) and the operation is finished.

When the eye heals after the operation, the drainage hole can sometimes become blocked by scar tissue.  If this happens, the eye pressure can go up again.  We often use a special chemical during the operation, to try to stop this excessive healing from happening.

Sometimes we perform a cataract operation at the same time as this glaucoma operation. This will be discussed with you at the time your name is placed on the waiting list for the operation.

Why do I need a Trabeculectomy?

Glaucoma can slowly damage the eyesight.  If you lose part of your eyesight because of glaucoma this damage is permanent and nothing can bring the sight back.  In Glaucoma, there is usually a problem with the pressure in the eye (the intraocular pressure).  The higher the pressure the greater is the chance of losing vision.

In the eye clinic, we monitor the eye pressure, your optic nerve and the field of vision, so we can tell if there is a danger of noticeable sight loss.  If eye-drops fail to keep the pressure low enough, surgery may be recommended as an alternative treatment.  The operation for Glaucoma cannot make the eyesight better, but may reduce the chance of it getting worse by reducing eye pressure

Can there be any complications or risks?

This operation has a success rate of about 80%. This means that for 8 out of 10 people who have the operation, the eye pressure is reduced. If the operation does not work adequately, you may need to restart using eye-drops to help control the eye pressure. The operation may be done again or you may need a special laser treatment to reduce the amount of fluid being made inside the eye.

On rare occasions the eyesight might end up a lot worse than before the operation.  However, if you do not have the operation done, there is the risk of slowly losing the vision because of the glaucoma.

This type of surgery has similar risks to other types of eye surgery such as:

  • Infection in the eye, called endophthalmitis, which is very rare but can give rise to serious loss of sight.
  • Bleeding inside the eye.
  • Inflammation inside the eye.
  • Bruising to the eyelids and eye – this settles after a few weeks.
  • Allergy to the medication used.

If you experience any of the following problems after you have gone home following your operation, you should contact the ward immediately.

  • Excessive pain.
  • Loss of vision.
  • Increasing redness of the eye.
  • Sticky discharge from the eye.

How do I prepare for the operation?

Please read the information leaflet.  Share the information it contains with your partner and family (if you wish) so that they can be of help and support.  There may be information they need to know, especially if they are taking care of you following this examination.

Pre-operative Assessment

Before the surgery you will need to attend a pre-operative assessment.  At this visit you will be asked questions about your general health and blood tests and a recording of your heartbeat (sometimes referred to as an Electrocardiogram – ECG) are performed. These tests are to ensure that you are in good general health and well enough to undergo the surgery.  Measurements will also be taken of your eyes.  We will need to know what tablets and medicines you are currently taking and also if you are sensitive to anything else such as Elastoplast. It may be useful to write these down to bring to your assessment.

At this visit, you will be advised on what pre-operative preparations you need to make, such as altering medications. Do not stop taking your regular medication without having discussed this with your doctor or nurse first. Information about this assessment clinic is contained in a separate leaflet called ‘Assessment Prior to Eye Surgery’

What will happen?

Upon arrival

The operation is usually carried out as an overnight stay and you will need to be at the Eye Hospital for 7.30am on the morning of surgery or 1.00pm if your operation is for the afternoon. You will be advised about what time to arrive separately.  You need to report to the reception desk and you will then be directed to the Eye Ward.

  • Due to space restrictions, if you want to bring anyone with you we request only one person accompanies you. They will be requested to come back to collect you the next day.
  • Please bring a clean dressing gown and pair of slippers with you, with overnight clothing and toiletries.
  • If you use a hearing aid bring it with you.
  • Take your usual medications unless you have been advised to stop them prior to surgery.
  • Also bring any medications that you may need to take whilst you are in hospital, including inhalers, sprays.
  • Please use your normal eye drops (except those you have been told to stop) on the day of your operation
  • Do not wear any make up, nail varnish or jewellery other than a wedding ring, as you will need to remove it before your operation.
  • It is advisable not to bring valuables or money to the hospital; the Trust will not accept responsibility for loss or theft.
  • Eat and drink normally before coming into hospital unless you have been advised not to do so.
  • On arrival to the ward, a nurse will meet you and confirm the information that you gave at your pre-assessment visit.
  • You will be asked to get changed into a hospital gown and your dressing gown and slippers.
  • Patients are offered drinks and light snacks free of charge.
  • Visitors are asked to use the dining facilities in the main hospital or Women and Children’s hospital. A drinks machine is available on the ground floor.
  • During your stay, several checks are made to ensure the correct patient receives the correct procedure on the correct eye. These may seem tedious but are in the interests of your safety.

What happens afterwards?

  • The dressing will be removed the following day and the doctor will examine the eye. We will check the pressure and the stitches.
  • Most patients are allowed home the day after the operation.
  • The eye will feel a bit scratchy, because of the wound and its stitches.
  • The sight will probably be blurred for a few days or even a few weeks, but it should settle down to a similar level to that before the operation was done. You may need to change your glasses prescription, but it is best to wait 3 months before doing this.
  • After the operation, you will need to change the eye-drops that you use in the operated eye. In the operated eye you will need to stop using your glaucoma drops and start using steroid eye-drops, antibiotic eye-drops and dilating eye-drops. In the other eye, you should continue to use any glaucoma drops that you were using previously.

You will be given three sorts of eye-drop for the operated eye:

Cyclopentolate 1% dilating eye-drops

Use 2 times a day for 2 weeks

Chloramphenicol antibiotic eye-drops

Use 4 times a day for 6 weeks

Predforte 1% steroid eye-drops

Week 1 – Use 8 times a day

Week 2 and 3 – Use six times a day

Week 4 and 5 – Use four times a day

Week 6 and 7 – Use three times a day

Week 8 and 9 – Use twice a day

Week 10 and 11 – Use once a day

These instructions are a guide and will vary according to the individual patient. Please bring your list of eye-drops every time you visit the eye doctor. It is important to use these new drops as instructed, as they help the eye to heal properly after the operation.  It is important that you do not run out of eye drops.  If you need more drops between visits, ask your doctor.

Your glaucoma consultant runs a special post-operative glaucoma clinic. You will need to come to the clinic every week for the first few weeks. In this clinic, we may need to adjust the stitches, or give injections close to the operation site, to help the eye to settle down. If we do need to do any of these things, we will use some anaesthetic drops to numb the eye first.  Most patients do not find this any more uncomfortable than having their eye pressures checked. If you need more extensive treatment you may have to go back for further surgery.

This may be:

  • If the trabeculectomy is over-draining and the eye pressure is too low, then more sutures may be needed in the trapdoor flap. If the conjunctival wounds are leaking, then more sutures may be needed.
  • If the trabeculectomy is under-draining and the eye pressure does not come down, then the trapdoor flap may need to be revised or opened up more.

Please wear comfortable clothes in case you need to get changed into theatre gowns if we take you to the operating theatre.

In most patients, at some point after the operation, the doctor will need to do some form of ‘bleb manipulation’ in the clinic – e.g. stitch adjustment or removal, eye massage to open up the trapdoor flap, injection of anti-scarring drugs, etc. This does not mean that the operation has failed. It simply means that the flow of fluid out of the eye needs help. When a manipulation is done in clinic, you may need to stay in the clinic for most of the morning.

Should you require further advice on the issues contained in this leaflet, please do not hesitate to contact the Ophthalmology Department (01482) 816658 or (01482) 608788 (08:30am – 17:00pm Monday-Friday) or Out-of-Hours (01482) 604346 (Please listen to full voice message on how to access emergency out of hours service) 

How long does it take to recover after surgery?

It takes a few days for the discomfort to settle. Sutures are buried under the conjunctival surface; however, they may loosen and cause some degree of minor irritation. Your vision may be blurred for several days to weeks after surgery. If you are working, you will need to be aware that you will need a significant amount of time off work, i.e. at least two weeks. Generally, patients are seen every week for the first four weeks after surgery.

Important points to remember
  • Try to rest and do not do any strenuous activities.
  • Do not lift heavy items after surgery, until you are advised that this is OK.
  • Try to keep your head above the level of your heart at all times (i.e. no bending, stooping or lifting heavy objects).
  • Avoid smoky or dusty atmospheres.
  • Do not get water in the eye (back wash your hair for the first couple of weeks and avoid irritants such as soap near the eye).
  • No swimming for at least a month.
  • You will need to wear a shield over the operated eye at night for a few weeks. Try to avoid sleeping with the operated eye on the pillow.
  • Never rub your eye during the first 3 months after glaucoma surgery (unless instructed to do so).
Is it safe to drive after surgery?

It is your responsibility to ensure that you are safe and legal to drive. If you are not sure, then contact the DVLA and ask for advice. You may also wish to contact your insurance company to ensure that you are covered during the period after your surgery. In any case, it may be sensible to wait until you are no longer using the eye drops before driving as they can blur your vision.  Your depth perception may also be impaired making it more difficult for you to judge distances. The International Glaucoma Association (IGA) can give good advice with regard to glaucoma and driving. Contact details are on their website.

Your eye drop record

This table shows your current eye drop medication prescription. Please do not alter it yourself. Bring it to every appointment, so that your eye doctor can record any changes to your drops.

General Advice and Consent

Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.

Consent to treatment

Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.

The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:

  • you must be able to give your consent
  • you must be given enough information to enable you to make a decision
  • you must be acting under your own free will and not under the strong influence of another person

Information about you

We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.

We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.

Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.

If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.

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