Glue ear, grommets (ventilation tubes) and adenoids

Mr James W Fairley BSc MBBS FRCS MS
Consultant ENT Surgeon

---

© 1993 - 2010 JW Fairley   Last updated 20 Dec 2009

---

What is glue ear?

Glue Ear is a build-up of fluid behind the eardrum, in the middle ear.

• The fluid may be thick and sticky, or thin and watery.
• Either way it stops the ear drum and ossicles vibrating easily, so quieter sounds are not heard.
• Glue ear is the commonest cause of deafness in children.
• Adults can also be affected.
• Other names for glue ear are middle ear effusion and chronic secretory otitis media.

Glue ear is a middle ear disease, associated with poor Eustachian tube function.

The normal ear and hearing

The human ear is divided into three parts:

• outer ear
• middle ear
• inner ear

Outer ear

The outer ear consists of the pinna and the ear canal. The outer ear funnels sound waves in air to the eardrum.

Eardrum (tympanic membrane)

The eardrum is a paper-thin membrane, shaped like a miniature satellite dish, 8-10 mm diameter. The tympanic membrane forms the boundary between outer and middle ear.

Middle ear

The eardrum vibrates when sounds arrive through the external ear canal. The vibrations are transmitted to the inner ear via three small bones (ossicles) suspended in the middle ear.

Ossicles

The three little bones (oss-i-culls) are

• malleus (mal-ee-us) shaped like a hammer
• incus (ink-us) shaped like an anvil
• stapes (stay-peas) shaped like a stirrup

Their job is to concentrate the sound energy, collected by the relatively large area of the eardrum, onto the tiny footplate of the stapes.

The outer and middle ear work like an old mechanical gramophone in reverse. The gramophone needle picks up vibrations from the grooves in the record, passes them to a vibrating membrane, then into the large horn, and so to the outside world. The outer and middle ear collect sound from the outside world and concentrate it down to the stapes footplate. The footplate moves like a piston in the oval window, the opening of the inner ear.

Inner ear

The inner ear has two parts, the cochlea and the vestibular labyrinth.

Cochlea

The cochlea is the hearing part of the inner ear. It is a biological microphone. Sound vibrations are turned into electrical signals and sent to the brain in the nerve of hearing.

Vestibular labyrinth

The vestibular labyrinth of the inner ear is concerned with balance. Disturbance of the balance organ of the inner ear can cause vertigo.

Eustachian tube

The Eustachian tube connects the middle ear with the back of the nose. To hear normally, the eardrum and ossicles must be able to move easily. For this to occur, the middle ear must contain air at the same atmospheric pressure as the outer ear. Air in the middle ear comes from the back of the nose, via the Eustachian tube. The job of the Eustachian tube is to ventilate the middle ear, keeping the pressure in the middle ear the same as in the outer ear. Most middle ear diseases, including glue ear, are associated with poor Eustachian tube function. The health of the middle ear depends on the Eustachian tube working properly.

top of page

What causes glue ear?

Glue ear is usually caused by a problem with the Eustachian tube.

Temporary glue ear (less than 3 months)

• Most children get glue ear at some stage in their lives.
• It often follows after a cold or ear infection. Biofilms may form in some cases.
• The Eustachian tube is small and blocks easily.
• It then fails to ventilate the middle ear.
• Sticky secretions can't drain away, so fluid builds up in the middle ear.
• Movement of the eardrum and ossicles is impaired, causing partial deafness.

Most cases get better quickly after the cold resolves. A minority persist for months or years.

• Occasionally glue ear is caused by flying with a cold - the Eustachian tube is unable to equalise pressure during descent
• Diving with a cold is very likely to cause glue ear, or worse damage. All divers are taught not to dive with a cold.

Persistent glue ear (longer than 3 months)

Common reasons for persistent glue ear in children are

• Large adenoids at the back of the nose
• passive smoking

Sometimes glue ear runs in families, though it is not strictly speaking hereditary.

Less common reasons for persistent glue ear include

• Cleft palate
• Down's syndrome

Rarely, glue ear in an adult is caused by a tumour at the back of the nose.

Often, no particular cause is found.

top of page

What are adenoids?

Adenoids are cauliflower-like swellings of the immune tissue at the back of the nose.

• Normal adenoids probably help fight off infections.
• If they get too big, they cause blockage of the nose and Eustachian tube and cause more trouble than they are worth.
• In severe cases they can cause obstruction of breathing at night.

If the adenoids are very big, the tonsils are usually big too.

top of page

What are the symptoms of glue ear?

• Deafness of mild to moderate degree.
• Hearing loss often varies from week to week, being worse after a cold.
• Speech may be delayed, especially if deafness occurs early in childhood.
• Unclear speech and constant shouting are common.
• Later, education may be affected.
• Sometimes deafness is not suspected, but the child is thought to be inattentive, slow or lazy.
• Concentration may be poor.
• The child often seems to be "in a world of his own".
• Some sufferers get frequent earaches, usually worse at night.
• Repeated ear infections, with high temperature in some cases leading to fits.
• Poor balance and clumsiness may feature.
• Older children and adults often complain of noises in the ears - tinnitus.

top of page

How is glue ear diagnosed?

Diagnosis is based on history, examination and special investigations.

• The specialist may be able to see signs of fluid behind the eardrum with the otoscope (ear torch).
• This is not always possible, wax or discharge may block the view.
• Some children may not be sufficiently cooperative for examination.
• A tympanogram is a test carried out by the audiologist to check on how easily the eardrum moves. It takes about a minute. It is not a test of hearing ability, but a physical test on the movement of the eardrum. A flat trace on the tympanogram usually means glue ear.
• An audiogram (hearing test) is carried out on children old enough to cooperate with the test. This will help assess the degree of hearing loss.
• Sometimes, the only way to make the diagnosis is under general anaesthetic on the operating table.

top of page

What is the treatment?

Watchful waiting

The fluid frequently goes away by itself, so a policy of watchful waiting is usually advised. Around the age of 8, many children grow out of it, though this is only the average. Some will carry on having trouble into their teens.

• Blowing up balloons or an Otovent® device, to try and force air up the Eustachian tube, may help but the published results are very short term and not many children will persist with this treatment.
• Any exacerbating factors should be eliminated especially passive smoking.
• Antibiotics and painkillers e.g. Calpol® can be used for associated ear infections.
• Decongestants e.g. Sudafed® are often prescribed but have never been proven effective.
• Other medical treatments including
  • antihistamines
  • steroids
  • medicines to try and thin sticky mucus
  have all been used, but in trials none have been proven to be of any benefit.
• Dietary modification - cutting down on dairy products - is often advocated but again is of no proven benefit, and does carry risks in children who need their calcium

Better in summer, worse in winter

Glue ear can be seasonal, worse in the winter and better in the summer.

• An operation may be deferred if the child is seen in the spring.
• An operation is more likely to be recommended in the autumn.

Persistent glue ear (longer than 3 months)

• If deafness persists for longer than 3 months, an operation is usually needed.
• The decision to operate is always individual, based on all the factors in that particular case.
• For immediate relief, myringotomy and grommets insertion is highly effective.
• Removal of the adenoids may be recommended if the adenoids are enlarged, and where glue ear recurs after initial grommet insertion.

top of page

What about alternative treatments?

None of the following are of any proven help:

• Homeopathic medicines
• Chinese / Hopie ear candles
• Acupuncture
• Cranial osteopathy

Although many parents have seen improvements in their child following the use of various treatments, this is almost certainly because of the natural tendency for glue ear to improve. If half the children are going to get better anyway, we would expect a 50% success rate from a treatment with no real benefit, so long as it didn't make things worse. This is known as the placebo effect. We would also expect a 50% improvement on no treatment at all.

Hearing aids

A few ENT specialists recommend the use of hearing aids for children with persistent glue ear, hoping that the fluid will eventually clear without recourse to grommets. Sometimes, if glue ear has persisted a long time, the eardrum may become permanently damaged and will not hold a grommet. In such cases, a hearing aid may be the only way of restoring hearing.

top of page

What is a grommet / ventilation tube - how does it work?

A grommet is a tiny plastic tube, shaped like a miniature cotton reel, about 2mm diameter.

• It is fitted through a small cut in the eardrum (myringotomy).
• The tension of the eardrum grips the grommet around its waist.
• The cotton-reel shape stops it falling in or out, like a shirt stud in a button hole.
• The grommet allows air from the outer ear directly into the middle ear.
• Provided the grommet remains in position and is not blocked, the hearing returns to normal almost immediately.
• The grommet does not drain fluid out, it lets air into the middle ear.
• Another name for a grommet is a ventilation tube, sometimes abbreviated to tube or vt.
• The standard Shah grommet is designed to stay in position for about 9 months.
• Then the opening in the eardrum heals over and the grommet is pushed out.
• Longer term ventilation tubes are sometimes fitted.
• It is important to understand that a grommet does not cure the underlying cause of glue ear.
• A grommet does provide highly effective and immediate relief of deafness and earaches, while it is in position and working.
• This buys time, and allows normal education.
• Meanwhile the child has a chance to grow out of it.
• If adverse factors, such as passive smoking, are not dealt with, there is an increased risk that the glue ear will come back once the grommets come out.

top of page

How is the operation done?

Grommets insertion is normally a quick and simple day-case procedure.

• It is very delicate and normally done under general anaesthetic (patient fully asleep)
• The anaesthetic is usually given by injection into a vein in the back of the hand, or by gas.
• To prevent the needle from hurting, a local anaesthetic cream is applied about an hour beforehand.
• No external cut is needed.
• A microscope provides a magnified view of the eardrum.
• A small cut (myringotomy) is made in the eardrum, and the fluid in the middle ear is sucked out. The cut is like a tiny button hole in the eardrum. Sometimes, if the glue is very thick and sticky, like treacle, a second cut is needed. The second opening allows air in to the middle ear while the glue is sucked out. Sometimes ear drops have to be pumped in to thin the glue in order to suck it out.
• The grommet is fitted. It is held in position by the tension of the eardrum gripping it around the waist. The grommet's shape stops it falling in or out, like a shirt stud in a button hole. If the eardrum is badly thinned, stretched and damaged, it might not have the strength to hold a standard grommet in place. A bigger grommet (long term ventilation tube) might be used in such a case.
• Some eardrops are ususally applied at the end of the procedure.

If the adenoids are to be removed, this is normally done under the same anaesthetic. The adenoids are removed via the mouth. No external cut is needed.

top of page

What happens after the operation?

Children recover very rapidly from grommets insertion and should be able to return to school after a day or two.

• The hearing normally improves immediately, but don't worry if there is still some difficulty in the first weeks as it can take time in some cases.
• There may be a very slight earache, treated easily with Calpol, or paracetamol for older children.
• There may be slight bleeding from the ear in the first few days. This is normal and nothing to worry about.
• After adenoidectomy, the child should stay off school for 10 days and avoid contact with anyone who has a cold or other infection.
• There is a small risk of heavy bleeding from the nose.
• If this occurs you should telephone the hospital and/or attend your nearest Accident & Emergency department.

top of page

What about swimming and grommets?

• No swimming for the first two weeks.
• After that, surface swimming is allowed without earplugs.
• If your child wishes to dive or use water chutes, some well fitting silicone rubber earplugs such as Kapiseal® or Ear Putty® should be worn, preferably with a neoprene headband such as the Ear Band-it® to stop them from falling out.
• Bath water is much worse than swimming pool water, because it contains germs from the rest of the body and irritant soap.
• Bath water should not be allowed in the ears. The head should not be submerged in the bath.
• For hairwashing, either use earplugs, or a piece of cotton wool dipped in Vaseline® to provide a waterproof seal.

top of page

Does fluid discharge from the ear?

• In the first few days after operation there may be a slight discharge or bleeding from the ear. This is normal and nothing to worry about.
• After that there should be no discharge.
• If the ear runs persistently, and especially if the discharge is smelly, that means an ear infection.
• The infection is usually in the middle ear. The discharge comes out through the grommet. In severe cases it will not be possible to see the grommet because the discharge fills the ear canal (see photo).
• Infection may be caused by dirty water in the ear, or a cold.

top of page

How to treat ear infection in the presence of a grommet

• The infection is best treated with antibiotic/steroid eardrops such as Sofradex® or Gentisone HC®.
• The manufacturers of these drugs do not recommend using them in the presence of a perforated eardrum, because of the risk that the aminoglycoside antibiotic in the drops could cause damage to the inner ear and deafness.
• Despite these reservations, most ENT specialists agree that the risk of deafness from the infection is greater than the risk of using the drops, and that these combined antibiotic steroid drops are the most reliable way of treating ear infection in the presence of a grommet.
• In 2007, ENT-UK published recommendations on treating patients discharging ears in the presence of a perforated eardrum or grommet. Aminoglycoside ear drops should only be used to treat obvious infection, and for no longer than 2 weeks. Whenever possible and practical, a hearing test should be done before treatment.
• Another type of antibiotic drops, containing a quinolone which is does not carry any risk of damaging the inner ear, is Ciprofloxacin. At present, this is only available in the UK as Ciloxan® eye drops, and not as a combined product with steroids. Combined quinolone and steroid ear drops such as Ciproxin HC® are in use in other countries, and avoid the tiny risk of damaging the ear from the aminoglycoside. Since the ENT specialists preference for quinolones over aminoglycoside ear drops was clearly expressed in a British Medical Journal editorial in 2000, it is not clear why there has been such a delay in getting this combination licensed for use in the UK. Similar delays occurred in Australia until recently.
• In persistent infection and especially tube granuloma where bacteria become attached to the surface of the grommet as biofilm, causing a foreign body reaction and bleeding from surrounding eardrum, the grommet may have to be removed.

How to use ear drops

• Ear drops must be inserted correctly, otherwise they may not work.
• Eardrops should be applied at body temperature.
• To get the drops to body temperature, put the bottle in your pocket for 15 - 20 minutes before use
• The patient should lie on his side with the affected ear uppermost.
• Any discharge should be mopped gently away with a cotton bud.
• Pull the ear gently backwards to funnel the drops into the ear canal.
• You then massage the tragus (the piece of skin that sticks out just in front of the ear canal like an open trapdoor) to force the drops through the grommet into the middle ear.
• It is rather like plunging a blocked sink.
• The infection should clear up within a few days.
• Antibiotics taken by mouth are not very good in treating ear infections where there is a grommet present.

top of page

How will you know if you have an ear infection with a grommet? Is the temperature raised?

• Discharge (fluid running from the ear) is the main sign of infection with a grommet.
• The discharge may be any colour. Pale green, creamy yellow and orange brown are common. It may be bloody.
• Sometimes it will be painful, but often there is little or no pain.
• Temperature is usually normal, unlike an acute otitis media when the temperature will be raised.

What happens after the grommet comes out?

The grommet only helps while it is in the eardrum and open. The eardrum normally heals up and pushes the grommet out after six to twelve months. The time can taken varies from a few weeks to several years. Once the grommet has come out of the eardrum, it is no longer working.

• In 2 out of 3 cases, the hearing remains normal, there is no further build-up of fluid, and the condition is cured.
• If the Eustachian tube is still blocked, the glue ear can recur, and it may be necessary to operate again in 1 in 3 cases.
• Of patients who have a second set of grommets, about 1 in 3 will require a third, (1 in 9 overall) of those 1 in 3 will require a fourth set (1 in 27 overall) and so on.
• If the hole in the eardrum does not heal up, it may be necessary to repair it at a later date.

How do you know when the grommet is out?

Often, you won't know. If the grommet comes out, the eardrum heals up, and the glue ear doesn't come back, there may be no symptoms at all. That is why we recommend periodic check-ups, so we can tell you what is happening.

• Most patients don't notice anything when the grommet comes out.
• There may be a slight pain or discomfort.
• Occasionally, the grommet comes out with an ear infection, in which case there may be discharge or bleeding from the ear.

When we say the grommet has come out, we mean out of the ear drum. A grommet can sit in the ear canal, having come out of the ear drum. Sometimes it can be hard to tell, even for a specialist, whether a grommet is still in the right place. Wax, layers of skin, dried discharge, or a sharp bend in the ear canal, can all prevent a proper view.

• When a grommet is just sitting in the ear canal, it is not working.
• It is no longer doing any good.
• Mostly, it is not doing any harm either, and we just wait for it to come right out by itself.

Being very small, you won't always see a grommet when it comes out. They can easily get lost in the bedding. This doesn't matter. You don't need to keep a lookout for grommets. You should, however, pay attention to any recurrence of

• hearing problems
• earaches
• discharge
• bleeding from the ear

Any of these could indicate a problem needing further treatment. What happens to the grommet isn't too important. It's what happens to the ear that matters.

Will the ear bleed when the grommet comes out?

Not normally.

• Bleeding from the ear is most often caused by a tube granuloma.
• It is a sign of infection.
• Usually, if caught early, it can be treated successfully with ear drops.

top of page

Do grommets scar the eardrum?

Yes. But the scar doesn't have any noticeable effect on hearing. It is less of a problem than the scarring caused by repeated ear infections.

top of page

What are the complications of grommets?

Most grommet operations are straighforward and it is unlikely anything will go wrong. But all surgical procedures have risks. Apart from the general risk of having an anaesthetic in hospital, the particular complications of grommets are

• Infection. Normally shows as a discharge from the ear. Best treated with eardrops, they must be correctly applied in order to work properly.
• Persistent infection tube granuloma, often with bleeding from the ear. Probably due to bacteria becoming attached to the surface of the grommet as a biofilm and causing a reaction in the surrounding eardrum. If caught early, will usually respond to treatment with eardrops. Otherwise, the grommet may have to be removed to settle this infection.
• Perforated eardrum. The hole where the grommet was put does not always heal up. This may require further surgery to repair the perforated eardrum at a later stage. A grommet that stays in a long time (years) is more likely to leave a perforation. This does not necessarily mean the grommet should be removed. An eardrum which does not have very active healing will not push the grommet out. A grommet which stays in too long is probably the result, rather than the cause, of the perforation.
• Cholesteatoma. A ball of skin erodes the middle ear structures. Said to be a rare complication of grommet insertion. More likely that a small cholesteatoma (which may co-exist with glue ear) is not noticed at the first operation to fit a grommet. The cholesteatoma then grows and becomes obvious later.

top of page

I've heard that grommet operations are unnecessary

Insertion of grommets is the commonest operation performed on children in the UK and there has been controversy over how many of these operations are really necessary. In most cases, glue ear is a temporary self-limiting condition. Although grommets give immediate improvement in hearing, it is not sensible to subject a child to surgery if they are about to get better on their own. The difficulty lies in predicting who is going to get better without surgery and who is not. No-one has a completely accurate crystal ball for this, but experience allows us to have a fair idea. Factors that make us recommend grommets are:

• Length of history - the longer fluid has persisted, the less likely it is to clear up on its own. We would normally wait at least three months before deciding on grommets.
• Age of the child - the younger the child, the less likely the glue ear will clear up. The normal age for "growing out of" glue ear is eight or nine.
• Severity of the hearing loss - the more severe the loss of hearing, the more likely grommets will be recommended.
• The time of year - glue ear tends to get better in the spring and summer, worse in the autumn and winter. If we see a child with glue ear at the end of the summer, the chances are it will get worse not better, so an operation is more likely to be needed.
• Previous and family history - a child who has had glue ear before, or comes from a family where glue ear is common, is more likely to need grommets.
• Observing progressive damage to the eardrum - if the eardrum appears to be sucked in and thinned, or develops a retraction pocket, surgery is more likely to be recommended to try and prevent permanent damage. Sometimes the damage will progress anyway, even if grommets are fitted and adenoids removed.
• Earaches and infections - a child subject to frequent earaches and infections will get more benefit from grommets.

We may monitor the condition for months, or occasionally even years, before operating.

• We only operate on patients who have had a reasonable chance to get better on their own, yet show no signs of improvement.
• We do not carry out any unecessary operations.
• The pros and cons of surgery, and any possible alternatives, are always fully discussed before a decision is made.
• That decision is made solely in the best interests of the patient, following the principle of how we would like a member of our own family treated.

top of page

Further reading / links

www.ndcs.org.uk	National Deaf Children's Society - parent-friendly guide to glue ear
NHS Direct	NHS Direct information sheet on glue ear
www.deafnessresearch.org.uk	Latest research on causes of glue ear
www.nice.org.uk/CG060	NICE Clinical Guideline on Surgical management of otitis media with effusion in children - issued February 2008. Detailed, technical, written for healthcare professionals.
Use and abuse of Evidence Based Medicine	Grommets, doctors and spin doctors. by JW Fairley and IDB Hore.

Disclaimer

top of page

All information and advice on this website is of a general nature and may not apply to you. There is no substitute for an individual consultation. We recommend that you see your General Practitioner if you would like to be referred.

---