The otoscope is a medical device that examines the inside of the ears, but also the nose or throat. It is one of the doctor’s basic medical instruments, just like the stethoscope or blood pressure monitor.

The otoscope is used to perform an otoscopy, that is to say the examination of the external auditory canal of the ear and the eardrum of which it provides a clear and precise vision. Using a light source and a magnifying lens, the doctor can accurately detect the existence of redness, swelling, a sore or the presence of a foreign body in the ear.

Composition

Otoscopes are made up of several elements:

• a handle, which contains the power source;
• a head, in which the light source is usually located;
• a light source, which may be a halogen, LED, xenon or XHL (xenon halogen) bulb, or optical fibers;
• a x3 or x4 magnifying lens, which can be rotated in some models;
• a suitable ear speculum, plastic (disposable) or stainless steel (reusable).

Some otoscopes are coupled to computers which allow the observations to be read directly on the monitor screen and the images to be recorded for preservation. The very high resolution of the images and the possibility of zooming give them twice the magnification of the otoscope.

The otoscope is used to perform otoscopies, a basic examination of the ear in ENT. Otoscopies are used to diagnose common conditions such as otitis externa, acute otitis media, or other infections or inflammations.

Perform an otoscopy

The patient should be comfortably installed. The doctor examines both ears, starting with the presumed healthy ear, and compares them. The examination follows a certain protocol which makes it possible to observe:

• the pavilion: its color, texture, configuration;
• the external auditory canal: its walls, direction, diameter, content;
• the eardrum: its color, appearance, position, mobility, integrity.

Ear pathologies

The result of the otoscopy can diagnose different ear conditions:

• obstruction by a plug of earwax or a foreign body that the practitioner will extract;
• otitis externa;
• acute otitis media;
• tympanosclerosis (loss of elasticity of the eardrum).

Who uses an otoscope?

Otoscopies are performed by general practitioners, ENTs, pediatricians, emergency physicians, hearing aid specialists. These common examinations are performed in the hospital, in an office or during a home visit.

When to use an otoscope?

The doctor performs an otoscopy in certain situations:

• in babies or young children with fever to check if it is related to an ear infection;
• in case of inflammation;
• in case of hearing loss;
• in the event of a blocked ear sensation;
• to carry out local treatment;
• to monitor the course of chronic otitis;
• to perform a paracentesis (incision of the eardrum performed under anesthesia in certain difficult cases of infections).

Precautions to take

• a speculum must be chosen that is well suited to the otoscope model and especially to the patient (infant, child, adult);
• care must be taken to ensure that the battery of the otoscope is fully charged. The light intensity of some models gradually decreases when the battery is discharged to alert the need for recharging.
• stainless steel specula should be thoroughly cleaned and disinfected after each use. Plastic specula are disposable.

The different parameters

The choice of an otoscope is based on two essential parameters: the power source and the lighting.

Diet

It is supplied by three possible power sources, located in the handle:

• a rechargeable battery with an autonomy of approximately 10 hours, in the majority of models;
• batteries (2 AA batteries most often);
• a connection to the sector.

Rechargeable or battery-powered otoscopes have the advantage of greater maneuverability and can be used for home visits.

The light source

The choice of the light source is decisive for the quality of the observation. Most otoscopes have bulbs located in the head of the instrument. The downside of the bulb is that it hides part of the field of vision. Four types of bulbs exist:

• the halogen bulb, which provides warm light of low intensity and homogeneous lighting respecting colors and contrasts;
• an LED bulb, which gives cold light of very high intensity, homogeneous lighting, well-rendered colors and contrasts, and minimal energy consumption;
• the xenon bulb, which gives a cold, dazzling light, with weakly rendered colors and contrasts;
• XHL bulbs (allogeneic xenon), which offer a good compromise and allow for low intensity lighting, concentrated and homogeneous light, and good rendering of colors and contrasts.

Fiber optic otoscopes have their light source located in the handle, which allows for a wider field of view and illuminates the less accessible areas of the ear canal.

Other instruments for performing an otoscopy

• The binocular microscope equipped with an intense light source and an ear speculum also makes it possible to perform otoscopies and perform fine manipulations;
• The otendoscope equipped with a light and a camera connected to a computer makes it possible to follow the exploration of the auditory canal directly on the screen.

The first otoscope

The first otoscope was invented in 1834 by Jean-Pierre Bonnafont. The auditory canal was then illuminated by light reflected by a mirror in the direction of the ear.