Retraction of the tympanic membrane is a common condition that in severe cases may require treatment.
For our ears to work, the ear drum needs to be able to vibrate when sound waves hit it. In order for the ear drum to vibrate freely, it needs to have air at the same pressure on either side of the ear drum. See image below:
For our ears to work, the ear drum needs to be able to vibrate when sound waves hit it. In order for the ear drum to vibrate freely, it needs to have air at the same pressure on either side of the ear drum. See image below:
Air can easily get to the outside part of the ear, but the inner part of the ear (called the middle ear) gets air from a tube from the back of the nose. This is called the Eustachian tube. The tube is small, and can easily become blocked.
When the Eustachian tube is blocked, the moist lining of the middle part of the ear absorbs the air in the ear, and the pressure in the middle ear reduces. This can causes the ear to fill up with a sticky fluid we call glue (glue ear) or it can suck the ear drum into the middle ear - see diagram:
The following images show what an eardrum looks like normally (the first image), and what it looks like then it becomes retracted (the second image). In this case the back of the ear drum is particularly retracted, and it has worn away part of one of the hearing bones.
Sometimes, even when the Eustachian tube is working, and pressure in the ear is normal, the ear drum can remain retracted. This is because the retracted ear drum can become stuck, and scar tissue from infections can attach to the ear drum, and pull it further into the ear.
The majority of cases of retraction will get better with no treatment. However, it is still important to monitor the situation, as the retractions can get worse and cause damage to the structures in the middle ear. Specifically, they can cause the hearing bones in the ear to be worn away causing a permanent hearing loss.
The first image below shows a tympanic membrane that is very retracted, and has worn away almost all of the hearing bones, so the ear drum is stuck onto the inner aspect of the ear - the hearing organ (cochlea). The second image below shows a more common picture, with a retraction over the hearing bones, but the hearing bones still being present. The third image shows a more severe retraction, with erosion of the second hearing bone (and the edge of the ear canal - an 'autoatticotomy'), and the last image shows the stage at which the retraction has resolved, but the second hearing bone is missing.
The majority of cases of retraction will get better with no treatment. However, it is still important to monitor the situation, as the retractions can get worse and cause damage to the structures in the middle ear. Specifically, they can cause the hearing bones in the ear to be worn away causing a permanent hearing loss.
The first image below shows a tympanic membrane that is very retracted, and has worn away almost all of the hearing bones, so the ear drum is stuck onto the inner aspect of the ear - the hearing organ (cochlea). The second image below shows a more common picture, with a retraction over the hearing bones, but the hearing bones still being present. The third image shows a more severe retraction, with erosion of the second hearing bone (and the edge of the ear canal - an 'autoatticotomy'), and the last image shows the stage at which the retraction has resolved, but the second hearing bone is missing.
Retraction can also lead on to cholesteatoma. This is particularly concerning when dead skin collects in the retracted area causing infections. The earlier cholesteatoma is detected, the more straightforward it is to treat.
In most cases, retractions do not require any treatment (1). Sometimes, particularly in younger children and when there is glue ear as well as retraction, making a hole in the ear drum and putting a plastic tube to let air into the ear may be helpful. This is a grommet operation (see glue ear). In older children and adults, there is a question whether to do an operation to remove the retracted part of the eardrum, and rebuild a stronger eardrum that will not be sucked into the ear again. This is called ‘reinforcement tympanoplasty’, and is sometimes done at the same time as repair of the hearing bones (‘ossiculoplasty’) (2). Deciding when to do this depends on factors like whether the ear over a period of time is improving or worsening, looking for damage to the hearing bones, and seeing if there has been infections.
References:
1. The Natural Course of Tympanic Membrane Retractions in the Posterosuperior Quadrant of Pars Tensa: A Watchful Waiting Policy.
Bayoumy AB, Veugen CCAFM, Rijssen LB, Yung M, Bok JM. Otol Neurotol. 2020 Sep 3.
2. Cartilage tympanoplasty for posterosuperior retraction pockets of the pars tensa in children. Couloigner V, Molony N, Viala P, Contencin P, Narcy P, Van Den Abbeele T. Otol Neurotol. 2003 Mar;24(2):264-9.