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| Otoscope | |
|---|---|
 An otoscope, with a tube of disposable tips behind | |
| Synonyms | auriscope |
An otoscope or auriscope is a medical device used by healthcare professionals to examine the ear canal and eardrum. [1] [2] [3] This may be done as part of routine physical examinations, or for evaluating specific ear complaints, such as earaches, sense of fullness in the ear, or hearing loss. [2] [3]
An otoscope enables viewing and examination of the ear canal and tympanic membrane (eardrum). [2] As the eardrum is the border between the external ear canal and the middle ear, its characteristics can indicate various diseases of the middle ear space.[ citation needed ] Otoscopic examination can help diagnose conditions such as acute otitis media (infection of the middle ear), otitis externa (infection of the outer ear),[ citation needed ] traumatic perforation of the eardrum, and cholesteatoma. [3]
The presence of cerumen (earwax), shed skin, pus, canal skin edema, foreign bodies, and various ear diseases, can obscure the view of the eardrum and thus compromise the value of otoscopy done with a common otoscope, but can confirm the presence of obstructing symptoms.
Otoscopes can also be used to examine patients' noses (avoiding the need for a separate nasal speculum) and upper throats (by removing the speculum).[ citation needed ]
The most common otoscopes consist of a handle and a head. The head contains a light source and a magnifying lens, typically around 8 diopters (3× magnification),[ citation needed ] to help illuminate and enlarge ear structures. [3] The distal (front) end of the otoscope has an attachment for disposable plastic ear specula.
The examiner first pulls on the pinna (usually the earlobe, side or top) to straighten the ear canal, and then inserts the ear speculum side of the otoscope into the outer ear. It is important to brace the index or little finger of the hand holding the otoscope against the patient's head to avoid injuring the ear canal. The examiner then looks through the lens on the rear of the instrument to see inside the ear canal.
In many models, the examiner can remove the lens and insert instruments like specialized suction tips through the otoscope into the ear canal, such as for removing earwax. Most models also have an insertion point for a bulb that pushes air through the speculum (pneumatic otoscopy) for testing eardrum mobility.
Many otoscopes for doctors' offices are wall-mounted, with an electrical cord providing power from an electric outlet. Portable otoscopes powered by batteries (usually rechargeable) in the handle are also available.
Otoscopes are often sold with ophthalmoscopes as a diagnostic set.
Most otoscopes used in emergency rooms, pediatric offices, general practice, and by internists are monocular devices. These provide a two-dimensional view of the ear canal and its contents, and usually at least a portion of the eardrum.
Another method of performing otoscopy (visualization of the ear) is by using a binocular (two-eyed) microscope in conjunction with a larger plastic or metal ear speculum, which provides a much larger field of view. The microscope is suspended from a stand, which frees up both of the examiner's hands; the patient is placed in a supine position and their head is tilted, which keeps the head stable and enables better lighting. The binocular view enables depth perception, which makes removal of earwax or other obstructing materials easier and less hazardous. The microscope also has up to 40× magnification, allowing more detailed viewing of the entire ear canal, and of the entire eardrum (unless prevented by edema of the canal skin). Subtle changes in the anatomy can also be more easily detected and interpreted.[ citation needed ]
Traditionally, binocular microscopes are only used by otolaryngologists (ear, nose, and throat specialists) and otologists (subspecialty ear doctors). Their widespread adoption in general medicine is hindered by cost and lack of familiarity among pediatric and general medicine professors in physician training programs. Studies have shown that reliance on a monocular otoscope to diagnose ear disease results in a more than 50% chance of misdiagnosis, as compared to binocular microscopic otoscopy.[ citation needed ]
The pneumatic otoscope is used to examine the eardrum for assessing the health of the middle ear. This is done by assessing the eardrum's contour (normal, retracted, full, or bulging), its color (gray, yellow, pink, amber, white, red, or blue), its translucency (translucent, semi-opaque, opaque), and its mobility (normal, increased, decreased, or absent). The pneumatic otoscope is the standard tool used in diagnosing otitis media (infection of the middle ear). [4]
The pneumatic otoscope has a pneumatic (diagnostic) head, which contains a lens, an enclosed light source, and a nipple for attaching a rubber bulb and tubing. By gently squeezing and releasing the bulb in rapid succession, the degree of eardrum mobility in response to positive and negative pressure can be observed. The head is designed so that an airtight chamber is produced when a speculum is attached and fitted snugly into the patient's ear canal. Using a rubber-tipped speculum or adding a small sleeve of rubber tubing at the end of a plastic speculum, can help improve the airtight seal and also help avoid injuring the patient. [4]
By replacing the pneumatic head with a surgical head, the pneumatic otoscope can also be used to clear earwax from the ear canal, and to perform diagnostic tympanocentesis (drainage of fluid from the middle ear) or myringotomy (creation of incision in the eardrum). The surgical head consists of an unenclosed light source and a lens that can swivel over a wide arc. [4]
In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear. Its function is to transmit sound from the air to the ossicles inside the middle ear, and thence to the oval window in the fluid-filled cochlea. The ear thereby converts and amplifies vibration in the air to vibration in cochlear fluid. The malleus bone bridges the gap between the eardrum and the other ossicles.
Otitis media is a group of inflammatory diseases of the middle ear. One of the two main types is acute otitis media (AOM), an infection of rapid onset that usually presents with ear pain. In young children this may result in pulling at the ear, increased crying, and poor sleep. Decreased eating and a fever may also be present. The other main type is otitis media with effusion (OME), typically not associated with symptoms, although occasionally a feeling of fullness is described; it is defined as the presence of non-infectious fluid in the middle ear which may persist for weeks or months often after an episode of acute otitis media. Chronic suppurative otitis media (CSOM) is middle ear inflammation that results in a perforated tympanic membrane with discharge from the ear for more than six weeks. It may be a complication of acute otitis media. Pain is rarely present. All three types of otitis media may be associated with hearing loss. If children with hearing loss due to OME do not learn sign language, it may affect their ability to learn.
Earwax, also known by the medical term cerumen, is a waxy substance secreted in the ear canal of humans and other mammals. Earwax can be many colors, including brown, orange, red, yellowish, and gray. Earwax protects the skin of the human ear canal, assists in cleaning and lubrication, and provides protection against bacteria, fungi, particulate matter, and water.
A hearing test provides an evaluation of the sensitivity of a person's sense of hearing and is most often performed by an audiologist using an audiometer. An audiometer is used to determine a person's hearing sensitivity at different frequencies. There are other hearing tests as well, e.g., Weber test and Rinne test.
An ear is the organ that enables hearing and body balance using the vestibular system. In mammals, the ear is usually described as having three parts: the outer ear, the middle ear and the inner ear. The outer ear consists of the pinna and the ear canal. Since the outer ear is the only visible portion of the ear in most animals, the word "ear" often refers to the external part alone. The middle ear includes the tympanic cavity and the three ossicles. The inner ear sits in the bony labyrinth, and contains structures which are key to several senses: the semicircular canals, which enable balance and eye tracking when moving; the utricle and saccule, which enable balance when stationary; and the cochlea, which enables hearing. The ear canal is cleaned via earwax, which naturally migrates to the auricle. The ears of vertebrates are placed somewhat symmetrically on either side of the head, an arrangement that aids sound localization.
Conductive hearing loss (CHL) occurs when there is a problem transferring sound waves anywhere along the pathway through the outer ear, tympanic membrane (eardrum), or middle ear (ossicles). If a conductive hearing loss occurs in conjunction with a sensorineural hearing loss, it is referred to as a mixed hearing loss. Depending upon the severity and nature of the conductive loss, this type of hearing impairment can often be treated with surgical intervention or pharmaceuticals to partially or, in some cases, fully restore hearing acuity to within normal range. However, cases of permanent or chronic conductive hearing loss may require other treatment modalities such as hearing aid devices to improve detection of sound and speech perception.
Ophthalmoscopy, also called funduscopy, is a test that allows a health professional to see inside the fundus of the eye and other structures using an ophthalmoscope. It is done as part of an eye examination and may be done as part of a routine physical examination. It is crucial in determining the health of the retina, optic disc, and vitreous humor.
The ear canal is a pathway running from the outer ear to the middle ear. The adult human ear canal extends from the auricle to the eardrum and is about 2.5 centimetres (1 in) in length and 0.7 centimetres (0.3 in) in diameter.
Ear pain, also known as earache or otalgia, is pain in the ear. Primary ear pain is pain that originates from the ear. Secondary ear pain is a type of referred pain, meaning that the source of the pain differs from the location where the pain is felt.
Tympanometry is an acoustic evaluation of the condition of the middle ear eardrum and the conduction bones by creating variations of air pressure in the ear canal.
Pupillary distance (PD), more correctly known as interpupillary distance (IPD) is the distance in millimeters between the centers of each pupil.
Ear drops are a form of topical medication for the ears used to treat infection, inflammation, impacted ear wax and local anesthesia. They are commonly used for short-term treatment and can be purchased with or without a prescription. Before using ear drops, refer to the package insert or consult a health professional for the amount of drops to use and the duration of treatment.
A perforated eardrum is a prick in the eardrum. It can be caused by infection, trauma, overpressure, inappropriate ear clearing, and changes in middle ear pressure. An otoscope can be used to view the eardrum to diagnose a perforation. Perforations may heal naturally or require surgery.
Otomycosis is a fungal ear infection, a superficial mycotic infection of the outer ear canal caused by micro-organisms called fungi which are related to yeast and mushrooms. It is more common in tropical or warm countries. The infection may be either subacute or acute and is characterized by itching in the ear, malodorous discharge, inflammation, pruritus, scaling, and severe discomfort or ear pain. The mycosis results in inflammation, superficial epithelial exfoliation, masses of debris containing hyphae, suppuration, and pain. Otomycosis can also cause hearing loss.
A loupe is a simple, small magnification device used to see small details more closely. They generally have higher magnification than a magnifying glass, and are designed to be held or worn close to the eye. A loupe does not have an attached handle, and its focusing lens(es) are contained in an opaque cylinder or cone. On some loupes this cylinder folds into an enclosing housing that protects the lenses when not in use.
The stereo, stereoscopic or dissecting microscope is an optical microscope variant designed for low magnification observation of a sample, typically using light reflected from the surface of an object rather than transmitted through it. The instrument uses two separate optical paths with two objectives and eyepieces to provide slightly different viewing angles to the left and right eyes. This arrangement produces a three-dimensional visualization of the sample being examined. Stereomicroscopy overlaps macrophotography for recording and examining solid samples with complex surface topography, where a three-dimensional view is needed for analyzing the detail.
Ear instillation is the process of introducing otic medication or other liquids into the ear canal. Proper care is needed in delivering such liquids.
Otitis externa, also called swimmer's ear, is inflammation of the ear canal. It often presents with ear pain, swelling of the ear canal, and occasionally decreased hearing. Typically there is pain with movement of the outer ear. A high fever is typically not present except in severe cases.
The cone of light, or light reflex, is a visible phenomenon which occurs upon examination of the tympanic membrane with an otoscope. Shining light on the tympanic membrane causes a cone-shaped reflection of light to appear in the anterior inferior quadrant. This corresponds to the 4 o'clock to 5 o'clock position in the right eardrum and the 7 o'clock to 8 o'clock position in the left eardrum. The apex of the cone is at the most depressed part of the tympanic membrane, known as the umbo.
Middle ear barotrauma (MEBT), also known to underwater divers as ear squeeze and reverse ear squeeze, is an injury caused by a difference in pressure between the external ear canal and the middle ear. It is common in underwater divers and usually occurs when the diver does not equalise sufficiently during descent or, less commonly, on ascent. Failure to equalise may be due to inexperience or eustachian tube dysfunction, which can have many possible causes. Unequalised ambient pressure increase during descent causes a pressure imbalance between the middle ear air space and the external auditory canal over the eardrum, referred to by divers as ear squeeze, causing inward stretching, serous effusion and haemorrhage, and eventual rupture. During ascent internal over-pressure is normally passively released through the eustachian tube, but if this does not happen the volume expansion of middle ear gas will cause outward bulging, stretching and eventual rupture of the eardrum known to divers as reverse ear squeeze. This damage causes local pain and hearing loss. Tympanic rupture during a dive can allow water into the middle ear, which can cause severe vertigo from caloric stimulation. This may cause nausea and vomiting underwater, which has a high risk of aspiration of vomit or water, with possibly fatal consequences.
