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An otoscope is a medical device that is used to examine the ears. Providers use otoscopes to detect diseases during regular check-ups and to check for ear symptoms. The device potentially provides a view of the ear canal and eardrum. Since this membrane is the boundary separating the external auditory meatus from the middle ear, its characteristics may indicate various diseases. The presence of cerumen (ear wax), sebum, pus, canal edema, foreign body, and various ear diseases can obscure the view of the eardrum and thus seriously undermine the value of a procedure done with a general otoscope.
Using an otoscope
The most commonly used otoscopes consist of a handle and a head. The head contains a light source and a simple low power magnifying lens, typically around 8 diopters. The distal (front) end of the otoscope has a device for disposable plastic ears.
The doctor first straightens the ear canal by pulling on the pin, and then inserts the ear mirror side of the otoscope into the outer ear.
It is important to strengthen the hand while holding the otoscope on the patient’s head so as not to damage the ear canal by placing the index finger or little finger on the head. The doctor can then examine the lens on the back of the instrument and see the inside of the ear canal.
In many models, the lens can be removed, as this allows the doctor to insert instruments through the otoscope into the ear canal, for example, to remove wax. Most models also have an insertion point for a lamp capable of pushing air through a mirror called a pneumatic otoscope. This layer allows the doctor to check the mobility of the eardrum.
Many otoscopes used in doctors’ offices are wall-mounted, while others are portable. The wall-mounted units attach with a flexible power cord to the base and serve to hold the otoscope when not in use, as well as being a source of electrical power connected to a wall outlet.
Portable models are powered by a battery in the handle. They are usually rechargeable and can be powered by the base unit. Otoscopes are often sold with ophthalmoscopes as a diagnostic kit.
When should an otoscope be used?
An otoscope helps to determine:
- otitis media;
- external otitis;
- general condition of the ears;
- nose condition.
Conditions that can be diagnosed with an otoscope include otitis media and appearance, infection of the middle and outer ear. Otoscopes are also often used to view a patient’s nose (avoiding the need for a separate nasal speculum).
An ear examination is usually performed by a specialist or nurse as part of a complete physical examination. The ears may be examined when an ear infection is suspected due to fever, severe ear pain, or partial hearing loss. Patients are often asked to tilt their head slightly towards the shoulder opposite the ear being examined (the ear to be examined is directed upwards). The doctor or nurse holds the earlobe while the speculum is inserted into the ear and adjusts the position of the otoscope to get a clear view of the ear canal and eardrum.
Both parts are usually examined, even if the problem is only in one ear. The ear canal is usually covered in tiny hairs, and it is normal to have yellowish-brown earwax. The membrane is thin, shiny and pearly white to light grey.
The tiny bones of the middle ear can be seen by pressing against the membrane of the tympanic membrane, the light from the otoscope reflecting off the surface.
In the case of an ear infection, the eardrum looks red and swollen. If it is torn, there may be a liquid consistency flowing from the middle ear. The doctor may see scarring, retraction, or bulging of the eardrum.
Types of otoscopes
The most commonly used otoscopes are those used in emergency departments, childcare, and general practitioners. They are monocular devices and provide a two-dimensional view of the ear canal, its contents, and typically at least a portion of the tympanic membrane, depending on what is in the ear canal. Another method for performing otoscopy (visualization from the ear) is to use a binocular microscope in combination with a large metal ear speculum.
The benefits are as follows:
- better view of the ear;
- accurate determination of the cause of ear pain;
- ease of use;
- the ability to immediately clean the ears;
- greater magnification.
During examination, the patient lies on his back and has his head tilted, as this provides a much better view, better lighting, and, most importantly, depth perception. A binocular view is required to examine the ear. If wax or other material obstructs the view of the canal and view of the entire tympanic membrane, it can be easily and confidently removed with special suction tips or other microscopic hearing aids. In contrast, the lack of depth perception with a monocular instrument makes manipulation more time consuming and dangerous.
Another important advantage of a binocular microscope is that both hands of the doctor are free, as the device is suspended from the stand. The microscope has a 40-fold increase in power, and this allows you to view the entire ear canal and tympanic membrane in more detail if there is no canal edema.
Subtle changes in anatomy are much easier to detect and interpret than with a monocular view otoscope. Traditionally, only ENT specialists (otolaryngologists) and otologists (auxiliary ear doctors) acquire binocular microscopes and the necessary skills and training to use them.
Ear examination and test efficiency
No precautions are required during the examination of the ears. However, if an ear infection is present, examining the ears can cause some discomfort or pain. When there is an object in the ear canal, pressing on the otoscope can push it further into the ear and damage the eardrum. There is no preparation required before examining the ear with this device. The ear mirror, which is inserted into the canal, is cleaned and disinfected.
If there is excessive wax buildup, a specialist or nurse will remove some of it so that the eardrum can be seen more clearly.
If there is an infection, the patient may need to be treated with antibiotics, and if there is wax buildup in the ear canal, it can be rinsed or cleaned during the procedure.
This type of auditory exam is simple and harmless, but the process can irritate the infected external auditory canal, leading to rupture of the eardrum if performed incorrectly. When an object in the ear causes discomfort, pressing the otoscope without checking may cause the foreign body to be pressed inwards (damage to the eardrum or further irritation of the ear canal).
Checking the ears depends not only on the specialist himself, but also on the patient – it is necessary to report your pain in time, if any.
Studies have shown that reliance on a monocular apparatus for diagnosing ear disease results in more than a 50% chance of misdiagnosis compared to binocular microscopic otoscopy.
The cost of acquiring a binocular microscope is only one obstacle to its wider adoption in general medicine. The low level of awareness of binocular otoscopy among paediatricians and physicians in training programs is probably the more difficult hurdle to overcome.
Thus, general otologic diagnosis and ear care are largely left to the obsolete monocular otoscope.