The middle ear is an airtight box behind your eardrum. It contains the three tiny bones of hearing (the malleus, incus and stapes) and is lined by a layer of cells that produce mucous. The only normal exit for this mucous is via the Eustachian tube, which connects it to the back of the nose (the nasopharynx). This tube also allows air in and out to equalise the pressure in the middle ear.
It is thought that a mixture of infection and blockage of this tube causes the build-up of mucous in the middle ear. This is especially common in children, before the Eustachian tube has grown enough to work properly.
As this mucous can be thick and sticky, it is often termed ‘glue ear’, comparing the fluid to old-fashioned UHU-type glue.
Most children will have glue ear at some stage. It is especially common after colds or ear infections, which tend to occur during the winter months and after your child enters nursery or school — around this time they may be subjected to a lot of infections one after the other. Adults usually get glue ear after a prolonged cold or respiratory infection, but in older patients it is important to rule out blockages around the back of the nose, in the area of the Eustachian tube opening. This can be done in outpatients by examining the nose with an endoscope (flexible nasendoscopy).
When does glue ear need treating?
Glue ear only needs treating if it is persistent and causes problems with hearing, speech development and behaviour in children, or if the glue becomes infected and leads to repeated ear infections.
Glue ear will, however, often resolve itself as the Eustachian tube begins working again, and a period of ‘watchful waiting’ for three months or so is usually best, with you or your child being reassessed and their hearing checked after this time. A prolonged course of low-dose antibiotics, taken once daily at night, may be an option to help this process in children.
During this time (or while awaiting the insertion of grommets) there are some simple strategies to help you or your child:
- Avoid smoking near them, as this has been shown to make glue ear worse.
- Say their name clearly before speaking to them, and make sure they can see your face to aid word recognition.
- Let their teachers and carers know they have a hearing problem; it may help to sit them at the front of the class.
- You may wish to try an ‘Otovent’, available from larger chemists. This is a small nozzle that fits up the nostril and lets your child blow up a balloon through the nose, which is thought to help the Eustachian tube open — although research has failed to show any great objective benefit.
The operation
A grommet is a very small plastic drainage tube which is put into a minute hole made in the eardrum using a microscope. This is done with your child asleep (general anaesthetic) down the ear canal, and does not involve any cuts on the outside of the face or ear. In adults it can be done while you are awake under local anaesthetic, using a numbing cream or a small injection in the ear canal before the procedure.
A grommet creates an alternative ventilation passage to the Eustachian tube for the middle ear. When the grommet is put in, the glue can be removed and air is allowed into the middle ear, restoring its normal function.
If you or your child has problems breathing through the nose — causing a tendency to mouth-breathe, snore at night and have difficulty catching breath while eating — it may be necessary to perform nasal surgery at the same time to ease the blockage. In children it is common to remove the adenoids at the same time if they are enlarged (please see our Adenoidectomy information sheet).
Putting in grommets usually takes about 15 minutes, with removal of the adenoids an additional 15 minutes. Both procedures can be performed as a day case, allowing you to take your child home later that day.
After the operation
Your child (or you) will need 48 hours off work or school after grommets are put in under a general anaesthetic. It is possible to go back to work the same or following day if the procedure is performed while awake.
The ears should not be painful, but simple painkillers such as paracetamol should be sufficient if they are uncomfortable in the first day or so.
Sometimes you will be given a course of antibiotics or antibiotic eardrops to use on discharge from hospital, if the glue was infected when the grommets were put in.
Hearing should improve straight away, and often the outside world is uncomfortably loud for a short time while you or your child adjust to normal hearing.
Once the grommets have ‘bedded in’ after a week or so, it is fine to swim. It is sensible to put earplugs in and/or wear a waterproof headband, but cotton wool smeared with Vaseline jelly is perfectly adequate. This precaution is especially important in the bath or shower and when washing the hair, as soap makes the water more likely to go through the grommet and cause infection in the middle ear. The ears will need this protection for the whole time the grommets are in place. We or your GP can tell you whether they are still in by looking in the ear.
Flying is fine after grommets have been put in — indeed, ascending and descending in an aeroplane should be a much safer and less painful experience with grommets in. Ear infections can still occur, but are usually less severe than before; antibiotics or antibiotic eardrops may be required if the ears start to discharge.
It is important that, six weeks after the operation, the hearing is checked to make sure levels have returned to normal. There will then be periodic review in outpatients until the grommets come out, which they usually do of their own accord after about six to nine months.
After they come out, on average about 80% of children have no further problems, as the grommets seem to ‘kick-start’ the Eustachian tube into action. The remaining 20% may need further grommets if they get recurring problems, sometimes into adult life.
The hole in the eardrum in which the grommet sat usually heals quickly and spontaneously, but in a very small percentage of cases it persists, and may need an operation to close it at a later date. Conversely, sometimes grommets stay in for an excessively long time, and it may be necessary to remove them under a very short general anaesthetic if they cause problems.