Cone of light is directed to the right for the right ear
and to the left for the left ear.
The handle of malleus is directed to the left for the right ear
and to the right for the left ear.
Pars flaccida less obvious.
Thinner eardrum with barely visible cone of light.
A generally thicker eardrum
with no obvious cone of light visible.
High definition endoscopic image of normal left tympanic membrane.
1- anterosuperior, 2- anteroinferior, 3- posteroinferior, 4- posterosuperior
Superior vascular strip region tapering towards handle of malleus and umbo.
Similar vascular pattern seen as above.
The radial pattern of eardrum capillaries. Middle ear effusion present.
Figures show epithelial migration in centrifugal pattern from the umbo.
Established and completed epithelial migration of a patient's ear canal.
"Ripples" of epithelial migration along the external auditory meatus.
(Epithelial migration figures are courtesy of Dr G Revadi)
Eardrum can be very thin and transparent. However, one's should be able to differentiate an intact eardrum based on history and its otoscopic appearance. Healed eardrum perforation lacks of middle fibrous layer.
Watch video of atrophic and atelectatic tympanic membrane @ YouTube
This should not be mistaken as the actual eardrum. In some patient,
a similar layer aliken to normal eardrum can occur. There is an air-filled
space in between these structures.
This image shows a thin layer before the actual eardrum due to
dried secretion in the ear canal close to the tympanic membrane.
Tympanic annulus (arrows) clearly seen at the periphery of the eardrum in a patient with previous history of keratosis obturans. It is the thickened edges of the eardrum which forms a fibrocartilaginous ring and reside in tympanic sulcus.
Visible postero-superior segment of tympanic ring (arrows). Otitis media with effusion present with mild retraction of pars flaccida.
Small island of keratin collection adhered on medial surface of pars flaccida (arrow).
Attempts should be made to preserve this nerve during tympanoplasty.
These figures show the course or the chorda tympani nerve along the
postero-superior aspect of the tympanic annulus (arrow).
Chorda tympani nerve blends with tympanic annulus posteriorly and appears white (top left) and more obviously seen beyond transparent atrophic membrane (top right).
Retracted pars tensa and atrophic pars flaccida with obvious ossicular chain seen. (1 - handle of malleus, 2 - long process of incus, 3 - body of incus, 4 - tympanic membrane, arrow - incudomalleolar joint)
Watch video of chorda tympani nerve course in relation to the eardrum @ YouTube