Otoscopy

Otoscopy is the direct visualization of the external auditory canal and the tympanic membrane through an otoscope. It's a basic part of physical examination of the ear and should be performed before other auditory or vestibular tests. Otoscopy indirectly provides information about the eustachian tube and the middle ear cavity.

Purpose

• To detect foreign bodies, cerumen, or stenosis in the external canal
• To detect external or middle ear pathology, such as infection or tympanic membrane perforation

Patient preparation

• Describe the procedure to the patient, and explain that this test permits visualization of the ear canal and eardrum.
• Reassure him that the examination is usually painless and takes less than 5 minutes to perform.
• Tell him that his ear will be pulled upward and backward to straighten the canal, to facilitate insertion of the otoscope.

Procedure and posttest care

• When assembling the otoscope, test the lamp and be sure to attach the largest speculum that fits comfortably into the patient's ear.
• With the patient seated, tilt his head slightly away from you so that the ear to be examined is pointed upward.
• Pull the auricle up and back (pull downward if the patient is under age 3); insert the otoscope gently into the ear canal with a downward and forward motion. If insertion is difficult replace the speculum with a smaller one.
• Look through the lens, and gently advance the speculum until you see the tympanic membrane. Obtain as full a view as possible, and note redness, swelling, lesions, discharge, foreign bodies, and scaling in the canal. Check the tympanic membrane for color, scarring, contours, and perforation.
• Locate the malleus, partially visible through the translucent tympanic membrane. Examine the membrane itself and the surrounding fibrous rim (annulus).

Precautions

• The otoscope should be advanced slowly and gently through the medial portion of the ear canal to avoid irritation of the canal lining, especially if an infection is suspected.
• Continuing to insert an otoscope against resistance may cause perforation of the tympanic membrane.

Normal findings

The normal tympanic membrane is thin, translucent, shiny, and slightly concave. It appears as a pearl gray or pale pink disk that reflects light in its inferior portion. The short process, manubrium mallei, and umbo should be visible but not prominent.

Abnormal findings

Scarring, discoloration, or retraction or bulging of the tympanic membrane indicates a pathologic condition. Movement of the tympanic membrane in tandem with respiration suggests abnormal patency of the eustachian tube.

Interfering factors

• Obstruction of the ear canal by cerumen or foreign matter
• Recumbent position during otoscopy (possible masking of serous otitis media)