Perforated Ear Drums
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:
a. if the ear is struck squarely with an open hand.
b. with a skull fracture.
c. after a sudden explosion.
d. if an object such as a bobby pin or Q-tip is pushed too far into the
ear canal.
e. as a result of hot slag from welding or acid entering the ear canal.
A small perforation (right) and a large subtotal one
(left) following otitis media.
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 occured 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
obvserve the perforation over time to see if it will close
spontaneously. They also might try to patch a cooperative patients'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.