The examination of the drum membrane is of great significance in clinic. Attention should be paid to the observation of the whole drum membrane especially the flaccid part. The following points should be paid attention to in the case of examination.
1. The colour of the drum membrane
The normal colour of the drum membrane is grayish white with luster. The surrounding area is whiter and there is a reflection cone of light on the anteroinferior part.. In the case of acute or chronic myringitis, the normal luster of the drum membrane and reflection cone of light may vanish, with accompanying pathological changes such as comgertion and pachynsis of various degrees, calcareous deposit, perforation or scar.
2. The position of the drum membrane
In the case of pathological changers, the position of the drum membrane changes and consequently the normal signs disappear. too. In the case of acute myringitis, the handle of malleus, the shout process of malleus, anterior and posterior plicae of malleus cannot be clearle seen because of the congestion of the drum membrane. In the pears umbonate. In the case of hydrops in the drum memrane, the membrane appears umbonate. In the case of obstruction of Eustachian btube, the air pressure of the tympanic cavity drops, the drum membrane invaginates and the handle of malleus moves backwards in a horizontal position. Therefore, the short process of malleus and anterior and posterior plicae of malleus become more obvious, with incomplete cone of light.
3. The perforation of the drum membrane
Pay attention to the position, size and pathological changes of the perforation. In the case of traumatic perforation, it mostly appears irregular with the fissured shape and acute; in the case of the small central perforation with throb, this shows acute suppurative inflammation of the middle ear and inadequate drainage; in the case of the small central perforation seen in the patients with chronic auricular pyorrhea, this indicates a mild pathological changes. The phenomena indicate more serious pathological changes of large central perforation of the drum membrane, vanishment of most of the drum membrane, pus in the perforation, granulation tissue, putrefactive auditory ossicles, etc. Serious pathological changes exist in the crypts when marginal perforation occurs in the drum membrane, especially in the flaccid region, together with odour of pus and cholesteatoma in the flaccid region, together with odour of pus and cholesteatoma in the perforation.
The application of an electric otoscope (with the light source and a magnifier) in examination is convenient for the observation of subtle pathological changes.
A pneumatic otoscope is used to determine the mobility of the drum membrane. One end of the otoscope may be attached to the otoscope of a different size while the other end is enclosed by a magnifier. There is a small tube beside the ososcope which can be attached to a balloon. The drum membrane can be observed by applying a frontal mirror to reflect the light onto the magnifier. When the balloon is squeezed, the drum membrane will move inwards and when the balloon is relaxed, the drum membrane will move outwards. In the case of myringeal adhesion, the drum membrane does not move when the balloon is squeezed.