Chapter 13: Special Senses

Rebecca Ray

• EARS– PE tube

– EENT

– BC

– AU

– OM

• EYES– EM

– XT

– OS

– EOM

– VA

Let’s look at ten abbreviations often used in treating the eyes and ears of patients.

PE: Pressure Equalizing TubePE tubes are used frequently, especially in small children, to help equalize the pressure on both sides of the eardrum.The tube is small and plastic and usually falls out by itself over time.Speaking from personal experience, my third pair of PE tubes never fell out and they had to be removed. Then I needed a skin graft to repair my tympanic membrane. They took a small amount of the thin skin from behind my ear to graft.

EENT

EENT stands for Eyes, Ears, Nose, and Throat, adding an extra specialty to the usual ENT (otolaryngology).At left there is a chart depicting the various stages of ear infections.

BC: Bone Conduction

Bone conduction is an important part of hearing. Not only do we hear by the mechanical movement of sound waves through the ear itself, but also by the sound waves conduction by the bones in our skull.Some modern hearing aids use this principle to amplify sound without the need for a device placed in the ear.SCUBA divers also can use a similar device to be able to hear others underwater.

AU: Both Ears & OS: Left Eye

While AS for “auris sinistra” and AD for “auris dextra” made sense to me as abbreviations, I had to dig out my Latin dictionary to decode AU. There is a word “utraque” that means “both.”

This word is also used in the medical abbreviations for OS, OD, and OU, all referring to the eyes (oculus sinister, dexter, and utraque).

OM: Otitis Media

Middle ear infections involve an accumulation of fluid and perhaps also air behind the eardrum.Infections can be bacterial, viral, or even fungal. Often the culprit is Haemophilus influenzae, but any number of microbes may be to blame.Ear infections are extremely common in children, but less so in adults. Consider the difference between the Eustachian tubes (at left). Children have a horizontally placed tube while adults have one that slants more and drains more efficiently.

EM: EmmetropiaFrom the Greek meaning “well-measured vision,” emmetropia is the natural state of vision: looking forward into the middle distance.

Eyes that are not “well-measured” may exhibit myopia or hyperopia, or nearsightedness and farsightedness.

The image at right is a clever take on the Snellen eye charts used to check vision.

XT: Exotropia

Exotropia means “turning outward” in Greek and it is used to describe one type of strabismus. See the four types depicted at left.

Strabismus occurs due to weakened eye muscles. The eyes have four rectus and two oblique muscles each.

EOM: Extraocular MovementExtraocular muscles control movement of the eyes. See the diagram indicating the six muscles that control the movement of each eye.

VA: Visual AcuityVisual acuity is measured using a Snellen eye chart at a distance of 20 feet.

20/20 vision is considered optimal visual acuity, while someone with 20/40 vision would need corrective lenses and someone with 20/10 vision can be considered to have excellent vision.

The metric equivalent is 6/6 (6 meters=20 feet).

Snellen-type charts that use pictures instead of letters can be used for small children and patients who are unable to read.