Perforations of the Eardrum
A perforated eardrum is a hole or rupture in the eardrum, a thin membrane which separates the ear canal and the middle ear. The medical term for the ear drum is the tympanic membrane. The middle ear is connected to the nose by the eustachian tube, which equalizes pressure in the middle ear. A perforated eardrum is often accompanied by decreased hearing and occasional discharge. Pain is usually not present.
NORMAL ANATOMY OF THE EAR DRUM
This image shows a normal eardrum. Note that the eardrum is partially translucent and that some of the structures behind it (and therefore in the middle ear) can be seen. The straight white structure running at an angle from the center of the eardrum to the upper right is the malleus, the first of the three bones of the middle ear. The faint white structure just to the left of the malleus is the joint between the second and third bones of the middle ear, called the incus and the malleus.
CAUSES OF EARDRUM PERFORATION
The causes of perforated eardrum are usually from trauma or infection. Some examples of situations which can cause perforated ear drums are:
- if the ear is struck squarely with an open hand.
- with a skull fracture.
- after a sudden explosion.
- if an object such as a bobby pin or Q-tip is pushed too far into the ear canal.
- as a result of hot slag from welding or acid entering the ear canal.
Middle ear infections may cause pain, hearing loss and spontaneous rupture (tear) of the eardrum, resulting in a perforation. In this circumstance, there may be infected or bloody drainage from the ear. In medical terms, this is called otitis media with perforation. On rare occasions a small hole may remain in the eardrum after a previously placed pressure equalization tube either falls out or is removed by the physician.
This image shows a small perforation in the eardrum. The drum itself is bloody and less translucent than the normal case. There are no signs of infection, so this perforation most likely occurred due to trauma to the eardrum.
NATURAL COURSE OF EARDRUM PERFORATIONS
Most eardrum perforations heal spontaneously within weeks after rupture, although some may take up to several months. During the healing process the ear must be protected from water and trauma. Those eardrum perforations which do not heal on their own may require surgery.
EFFECTS OF HEARING FROM PERFORATED EARDRUMS
Usually, the larger the perforation, the greater the loss of hearing. The location of the hole (perforation) in the eardrum also affects the degree of hearing loss. If severe trauma (e.g. skull fracture) disrupts the bones in the middle ear which transmit sound or causes injury to the inner ear structures, the hearing loss may be quite severe.
If the perforated eardrum is due to a sudden traumatic or explosive event, the loss of hearing can be great and ringing in the ear (tinnitus) may be severe. In this case the hearing usually returns partially, and the ringing diminishes in a few days. Chronic infection as a result of the perforation can cause major hearing loss.
TREATMENT OF THE PERFORATED EARDRUM
Before attempting any correction of the perforation, a hearing test should be performed. The benefits of closing a perforation include prevention of water entering the ear while showering, bathing or swimming (which could cause ear infection), improved hearing, and diminished tinnitus. It also may prevent the development of cholesteatoma (skin cyst in the middle ear), which can cause chronic infection and destruction of ear structures.
If the perforation is very small, otolaryngologists may choose to observe the perforation over time to see if it will close spontaneously. They also might try to patch a cooperative patient's eardrum in the office. Working with a microscope, your doctor may touch the edges of the eardrum with a chemical to stimulate growth and then place a thin paper patch on the eardrum. Usually with closure of the tympanic membrane improvement in hearing is noted. Several applications of a patch (up to three or four) may be required before the perforation closes completely.
If your physician feels that a paper patch will not provide prompt or adequate closure of the hole in the eardrum, or if attempts with paper patching are not successful, surgery is considered. There are a variety of surgical techniques, but all basically place tissue from another part of body across the perforation to promote healing. Popular type of tissue to use include the heavy covering of muscle called fascia and thinned cartilage from the ear. The name of this procedure is tympanoplasty. Surgery is typically quite successful in closing the perforation permanently and improving hearing. It is usually done on an out-patient basis.
Your doctor will advise you regarding the proper management of a perforated eardrum.
(information adapted from the American Academy of Otolaryngology-Head and Neck Surgery, Alexandria, VA.)