About the ear. The ear is made up of three parts - the outer, middle and inner ear. Under normal circumstances, sound waves come into the outer ear and touch the eardrum, causing the eardrum to shake back and forth. Immediately behind the eardrum is the middle ear, which contains three tiny bones (in fact they are the smallest bones in the body!) called the malleus, incus and stapes, collectively known as the ossicles. The vibrations transmit from the eardrum to these tiny bones in the middle ear. The bones then pass the vibration to a structure in the inner ear called the cochlea. The vibrations cause special cells in the cochlea to move, generating 'signals' which are sent down the nerve to the brain, so we 'hear'. Air normally fills the space in the middle ear. The middle ear is connected to the throat by a structure called the auditory tube or the Eustachian tube. The function of Eustachian tube is to normalize or equalize air pressure between the middle ear and the atmosphere. This tube is normally closed, however, from time to time, it opens to allow air to get in and fluid to drain out. Tell me more about glue ear. Glue ear is a condition when the middle ear, which is normally filled with air, becomes filled with fluid. The fluid looks and feels like glue and hence the name of the condition. The correct medical term used to describe glue ear is 'otitis media with effusion' or OME. Commonly, only one ear is affected, however both ears can become affected as well. As the density in the middle ear changes from low to high as air is replaced by fluid, the vibrations made by the sound saves in the eardrum and the bones dampen. As a result of that, the cochlea receives low volume 'signals'. Glue ear commonly affects children, however, adults can be affected as well. What are the causes of glue ear? Researchers are still searching for the cause and mechanism of glue ear. The exact cause is still unclear. However most researchers believe that it is most likely due to the auditory tube not functioning properly. The amount of air and fluid in the middle ear may change if the auditory tube is blocked or narrowed. When the auditory tube is blocked, air get absorbed by the nearby cells in the middle ear, a vacuum develop, causing fluid to seep into the middle ear by the nearby cells. Is glue ear common? Yes, it affects seven in ten children at some stage in their life. Boys are at greater risks than girls. One episode predicts another, children who have one episode are likely to have recurrent glue ears. Other risk factors include: - Lives at home where people smoke. - Have a family history of glue ears (siblings who have glue ears) - Have recurrent cough and cold. - Were bottle fed rather than breast fed. What are the symptoms of glue ear? Dulled hearing. This is by far the commonest symptom. Sometime children who are affected may become completely deaf. Hearing loss can range from mild to severe. If it persists, it will affect the child's normal intellectual development. Pain. This is uncommon, but mild earache may occur from time to time. Affected children may pull at their ears if they have pain. Behavioral problems. Children with glue ear tend to have behavioral problems and slower speech development. These are commonly due to the fact that they cannot hear well. Can it be treated? Yes. However, most glue ears will resolve on their own. If glue ear persists, surgery may be needed to remove the glue-like fluid from the middle ear and to place a 'grommet' (ventilation tube) in the ear drum. The grommet is a tiny device which acts like an auditory tube. It sits across the eardrum connecting the outer and middle ears, hence allowing pressure in the middle ear to normalize or equalize with the atmosphere. |
