SPECIAL SENSES: EYES & EARS

By: Arneshia McConnell

Both Ears (AU)

The ear is subdivided into three areas: External ear Middle ear Inner Ear

The study of the ear is known as otology.

The study of ear disorders is known as audiology.

Diagram of Ear Section

Otitis Media (OM)

Otitis Media is inflammation of the middle ear. The inflammation can occur as a result of an

infection extending up the eustachian tube. This tube may become blocked by a bacterial or viral

infection or by enlarged adenoids. Fluid produced by the inflammation cannot drain off

through the tube and instead collects in the middle ear Four main causes:

Allergy Infection Blockage of the eustachian tube Nutritional deficiency

Otitis Media (OM) – Cont’d

Treatments include: Antibiotics

Surgery (if antibiotics fail) Myringotomy (involves insertion of PE tube

through small incision in the eardrum) Adenoidectomy (surgical removal of

adenoids) This is usually a last resort.

Pressure Equalizing Tube (PE tube)

Small tube surgically placed in a child’s eardrum to assist in drainage of trapped fluid and to equalize pressure between the middle ear cavity and the atmosphere.

Tiny, hollow tube made of soft material Known by other names:

Tympanostomy tubes Ventilating tubes

Doesn’t cause hearing loss or long term damage to the ear drum.

Bone Conduction (BC)

Bone conduction is the conduction of sound through the bones of the skull.

Two types: Compressional: high-pitched sounds cause

the segments of the skull to vibrate individually.

Inertial: low-pitched sounds vibrate the entire skull, causing it to move while the suspended sensory parts of the inner ear remain at rest.

Eye, Ear, Nose, and Throat (EENT)

Patient services include diagnostics, medical treatment, and surgical services for eye, ear, nose, and throat.

A patient experiencing allergy symptoms would see an EENT specialist.

Diagram of Eye, ENT diagram

Left Eye (OS)

The study of the eye is known as ophthalmology.

The eyeball is the organ of sight that transmits an external image by way of the nervous system – the optic nerve – to the brain.

In addition to the eyeball, several external structures play a role in vision: Eye muscles Eyelids Conjunctiva Lacrimal apparatus

Extraocular Movement (EOM)

Refers to eye movements There are the six extraocular muscles, which

act to turn or rotate an eye about its vertical, horizontal, and antero-posterior axes: medial rectus (MR), lateral rectus (LR), superior rectus (SR), inferior rectus (IR), superior oblique (SO), and inferior oblique (IO).

Left Eye Diagram of Extraocular Muscles

Visual Acuity (VA)

Refers to the measurement of the sharpness of a patient’s vision.

Usually, a Snellen chart is used for this test A patient identifies letters on a chart

from a distance of 20 feet.

Snellen Chart

Emmetropia (EM)

Emmetropia is referred to as state of normal vision.

A person with emmetropia (perfect vision) doesn’t need eyeglasses or contacts.

The reason for this is that the light that enters a person’s eye bends correctly

Exotropia (XT)

Refers to outward turning of the eye (also called wall-eyed)

Form of strabismus (muscle weakness of the eye) Symptoms:

Decreased vision Misaligned eyes Sensitivity to light

Treatment: Although glasses, exercises or prisms may reduce or

help control the outward turning eye in some children, surgery is often needed to correct exotropia, obtain 3-dimensional vision, and prevent permanent vision loss.

Examples of Exotropia

Sources

http://www.cincinnatichildrens.org/health/info/ent/procedure/pe-tube.htm

http://www.eyedesignbook.com/ch6/eyech6-a.html

http://www.contmediausa.com/shop/app/products/Human3D/human3dhumanear.html

http://www.bangkokpattayahospital.com/en/ent_center.php

http://www.britannica.com/EBchecked/topic/72920/bone-conduction

Sources (Cont’d)

http://www.healthscout.com/ency/68/611/main.html

http://www.wisegeek.com/what-is-emmetropia.htm

http://www.kellogg.umich.edu/patientcare/conditions/exotropia.html

http://www.pedseye.com/Exotropia.htm http://www.yorku.ca/eye/muscle.htm http://

www.disabled-world.com/artman/publish/eye-chart.shtml