Using Otoscopes in Ear Examinations

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The Ear

Since symptoms of ear disease are relatively few in number and frequently nonspecific, a clinical examination of the ear is important in the management of ear disorders.

When a patient complains of ear pain, examination of the ear is indicated to differentiate whether the patient’s disorder is an ear infection or a disorder originating in adjacent structures, such as the tempomandibular joint, the teeth or the tonsils. As the only window into the middle ear, the appearance and behavior of the tympanic membrane offer valuable information about possible disease within the middle ear.

Fortunately, the ear provides easy access for examining and diagnosing disorders of the complex and interrelated ear, nose and throat system. The otoscope, when used correctly, is the single most important diagnostic tool available to the practitioner for determining whether the ear is the source of the patient’s complaint.

Otoscopy is one of the primary methods a practitioner uses for diagnosing patient complaints for the entire ear-nose-throat complex. Use of a well-designed otoscope which provides illumination, magnification and air pressure capability for checking tympanic membrane mobility is, therefore, essential, allowing the practitioner to view the ear canal and, in particular, the tympanic membrane with clarity.

How to Conduct an Otoscopic Examination

1. Carefully inspect the pinna and postauricular skin. Gently palpate the pinna to determine if any tenderness exists.

2. Inspect the entrance to the ear canal for debris or pus, which might interfere with further examination.

3. Choose the largest speculum that can comfortably be inserted into the ear canal. Straightening the outer ear canal makes insertion of the speculum easier. For adults, this is accomplished by retracting the pinna upwards and backwards. For children, this is accomplished by retracting the pinna horizontally backwards.

4. When using a MacroView otoscope, set the focusing wheel of the otoscope to the default position by aligning the green line on the focusing wheel with the corresponding green dot on the side of the instrument. You will feel the focusing wheel settle into the default setting. The majority of the exams can be completed at the default focusing position.

5. There are two common ways to hold the otoscope. The first way is to hold the otoscope like a hammer by gripping the top of the power handle between your thumb and forefinger, close to the light source. You can conveniently hold the bulb of the pneumatic attachment between the palm of the same hand and the power handle. It is recommended that you extend the middle and ring finger outward so they come into contact with the person’s cheek. This way, any sudden flinch by the patient will not cause the otoscope to be jammed into the ear canal. The otoscope can also be held like a pencil, between the thumb and the forefinger, with the ulnar aspect of the hand resting firmly but gently against the patient’s cheek. You can hold the bulb of the pneumatic attachment in the palm of the same hand. If the patient turns or moves, the otoscope will move in unison with the patient’s head. This will avoid possible injury to the ear canal or even the tympanic membrane. It is very important that the otoscope be held correctly, particularly when examining children. A sudden movement by the patient could cause the skin on the inside of the ear canal to be pierced by the end of the speculum.

6. It may be necessary to adjust the line of sight and the position of the speculum to get a complete view of the entire ear canal and all areas of the tympanic membrane. This yields a composite view of the external canal and the tympanic membrane.

7. If the tympanic membrane or desired area in view is not in focus, the practitioner has the option to adjust the focal length of the optics system of the MacroView otoscope. To adjust the focal length, place a finger on either side of the focusing wheel or on the back eyepiece of the otoscope. To shorten the focal length or zoom in, rotate the focusing wheel towards the smaller dashes on the side of the otoscope. To increase the focal length or zoom out, rotate the focusing wheel towards the longer dashes.

8. After the examination is complete, the used specula should be removed from the otoscope.

Pneumatic Otoscopy

Pneumatic otoscopy provides practitioners with a simple method for determining tympanic mobility and helps then recognize many middle ear disorders.

It is the pneumatic capability and insufflator attachment of the otoscope which enable the examiner to assess the mobility of the intact tympanic membrane. This first requires that you use a speculum sufficiently large to fit snugly into the ear canal in order to establish an airtight chamber between the canal and the interior of the otoscope head.

Gently squeezing the insufflator attachment produces small changes in the air pressure of the canal. By observing the relative movements of the tympanic membrane in response to the induced changes in pressure, the practitioner can obtain valuable diagnostic information about the mobility of the tympanic membrane. When fluid is present in the middle ear, for example, movement of the tympanic membrane is generally diminished or absent. The pneumatic otoscope may also be useful in distinguishing between a thin atrophic intact tympanic membrane adherent to the medial wall of the middle ear, which can be made to move, and a large perforation, which will not move. This procedure provides a simple method for determining tympanic membrane mobility and is of value in the recognition of many middle ear disorders.

Common Pathologies of the Ear

Normal Tympanic Membrane

The normal tympanic membrane (TM) is a pale, gray, ovoid semitransparent membrane situated obliquely at the end of the bony external auditory canal. The handle of the malleus is seen extending downwards and backwards, ending at the apex of the triangular “cone of reflected light.” The long process of the incus and its articulation with the head of the stapes may frequently be seen through the postero-superior quadrant of a thin tympanic membrane. The mobility of an intact TM can readily be assessed by using the pneumatic attachment to the otoscope.

Red Reflex (Right Ear)

The introduction of a speculum into the external auditory canal may cause a reflex dilatation of the circumferential and manubrial blood vessels supplying the tympanic membrane.

Following a prolonged examination of the ear or in a crying child, this vasodilatation may produce an appearance mimicking that of an early acute otitis media.

Exostosis (Left Ear)

Exostoses appear as discreet, hard, round or oval outcroppings which are sometimes pedunculated. Exostoses in the ear canal are more often multiple than single and are usually bilateral. They are usually asymptomatic, extremely slow growing and seldom enlarge sufficiently to occlude the meatus. Multiple exostoses appear to result from the prolonged stimulation of the bony external canal with cold water and are consequently seen more commonly in persons who swim frequently.

Foreign Body

A varied selection of foreign bodies has been discovered in the ear canals of children. In this case, a large piece of sponge rubber was removed. In adults, a forgotten piece of cotton wool is frequently found. The foreign body or an unsuccessful attempt to remove it can both product secondary otitis externa or damage to the tympanic membrane and ossicles. In young children, it is sometimes safer to administer a short, general anesthetic.

Otomycosis

Otoscopic examination in cases of otomycosis reveals a white or cream colored, thickish debris which may have a fluffy appearance due to the presence of tiny mycelia. When the infection is caused by Aspergillus niger, it may be possible to identify the tiny grayish-black conidiophores. The underlying external canal skin is often inflamed and granular from invasion by fungal mycelia. Otomycosis may follow the use of topical antibiotic ear drops.

Acute Otitis Externa (Left Ear)

Trauma and moisture are the most common factors responsible for the development of acute diffuse otitis externa. The skin of the ear canal is painful, infected and swollen, and it may be impossible to visualize the tympanic membrane. There is often a considerable amount of keratin debris in the canal which must be removed if local treatment is to be effective. Gram negative and anaerobic bacteria are the most common pathogens; however, a culture of material should be a clinical consideration.

Acute Otitis Media

This acute infection of the middle ear cleft frequently intensifies upper respiratory tract infections and occurs more commonly in children. In the early stages, the tympanic membrane varies according to the stage of the disease. The tympanic membrane is retracted and pink with dilatation of the manubrial and circumferential vessels. Later, as the disease progresses, the tympanic membrane bulges, becoming fiery red in color and may eventually perforate, releasing pus into the external auditory canal.

Keratosis Obturans

In this condition of unknown etiology, the bony meatus is totally occluded by a stony, hard plug of whitish keratin debris. Keratosis obturans is more frequently seen in patients with bronchiectasis and chronic sinusitis. Removal of this material is extremely difficult because of its consistency and its frequent adherence to the underlying canal skin; a general anesthetic may be required in some patients.

Serous Otitis Media (Right Ear)

In serous otitis media the tympanic membrane is retracted and shows decreased mobility with pneumatic otoscopy. The handle of the malleus is usually foreshortened, chalky-white in color, and the lateral process is prominent. The presence of a thin, serous effusion within the middle ear gives the tympanic membrane a yellowish or even bluish appearance, and in cases of incomplete eustachian tube obstruction, air bubbles or an air fluid level may be seen.

Tympanostomy Tube (Right Ear)

A tympanostomy tube is often inserted into the tympanic membrane to ventilate the middle ear in cases of chronic serous otitis media. These tubes come in a variety of sizes, shapes and materials. The tympanostomy tube should be seen to be in place in the tympanic membrane with its lumen patent and free of any exudate or debris.

Chronic Suppurative Otitis Media (Left Ear)

Chronic suppurative otitis media is characterized by recurrent painless otorrhea. The discharge may vary from mucoid to frankly purulent. Pseudomonas, Proteus, and Coliforms are the three most commonly isolated bacteria; however, fungal organisms can also coexist.

Central Perforation of the Tympanic Membrane (Left Ear)

Perforations of the pars tensa of the tympanic membrane can result from infection or trauma. In this case the large central perforation resulted from repeated middle ear infections.

Tympanosclerosis (Right Ear)

Tympanosclerotic plaques of varying sizes are seen as chalky white deposits in the tympanic membrane. They occur as a result of a postinflammatory deposition of thickened hyalinized collagen fibrils in the middle fibrous layer of the tympanic membrane and indicate that the patient has had a previous significant ear infection.

Healed Central Perforation (Right Ear)

When a large perforation heals, the middle fibrous layer of the tympanic membrane remains deficient so that a thin semitransparent pseudomembrane resembling an open perforation may be seen. Gentle use of the pneumatic otoscope will, however, demonstrate that the drum is intact. This thinned segment of a healed tympanic membrane lacks the strength of a normal drum and forceful syringing may result in reperforation.

Tympanosclerosis Involving the Ossicles (Left Ear)

Tympanosclerotic plaques may also occur within the middle ear cavity. This photograph shows tympanosclerotic deposits enveloping the incudostapedial joint. A few plaques are also present on the promontory. Partial or total fixation of the ossicular chain by tympanosclerosis is responsible for some cases of acquired conductive hearing loss.

Adhesive (Atrophic) Otitis Media (Left Ear)

Following long-standing eustachian tube obstruction, the tympanic membrane may become atrophic and retracted onto the medial wall of the middle ear and ossicles. In this case, a thin atrophic tympanic membrane is draped over the head of the stapes and the tip of the long process of the incus has been eroded. It can sometimes be difficult to differentiate an atrophic, immobile, retracted tympanic membrane from a large central perforation. In this circumstance, pneumatic otoscopy is often of value.

Traumatic Perforation (Left Ear)

These perforations result from a variety of causes, including a blow to the ear, blast injury, or the insertion of a cotton tipped swab or bobby pin, but rarely follow forceful syringing. While traumatic perforations may be of any shape or size, they are usually small with clean-cut edges. Fresh blood may be seen in the deep meatus. Most traumatic perforations heal spontaneously, provided the ear canal is kept clean and dry to prevent secondary infection.

Cholesteatoma (Right Ear)

A cholesteatoma is a slowly expanding and eroding cyst lined with stratified squamous keratinizing epithelium which invades the middle ear cleft. The presence of whitish keratin debris within a postero-superior perforation indicates the presence of an underlying epidermoid cholesteatoma. Serious intracranial complications may result from the expansion and erosion of the cholesteatoma sac.