Chapter 10 Med Term Review

ambylopia

impaired vision in one or both eyes resulting from a developmental deficiency in early childhood; also known as a "lazy eye"

blepharitis

inflammation of the eyelid, resulting in redness, swelling, and crusting along the eyelid

cataract

clouding of the lens that results in decreased visual acuity; caused by accumulation of protein in the lens

chalazion

a small, hard, cystic mass on the eyelid caused by a blocked oil gland

dacryocystitis

blockage, inflammation, and infection of a nasolacrimal duct and lacrimal sac

diabetic retinopathy

a complication of diabetes marked by damage to the retina that can result in loss of vision

ectropion

eversion of the eyelid, which often leads to redness, pain, and corneal breakdown; generally associated with aging

entropion

inversion of the eyelid, causing the eyelashes to irritate the surface of the eye; can potentially cause corneal abrasion

glaucoma

disease in which intraocular pressure causes damage to the retina and the optical nerve, eventually producing blindness

hordeolum

purulent inflammation of an eyelid gland; commonly known as a sty

macular degeneration

progressive, usually age-related, deterioration of the macula that leads to vision loss

nystagmus

repetitive, usually involuntary movements of one or both eyes that results in limited visual acuity

refractive disorders

any of multiple disorders in which an irregularly shaped cornea or lens does not allow light rays to focus properly on the retina, resulting in blurred vision

astigmatism (As.)

defective curvature of the cornea that produces blurred vision; may be present with nearsightedness or farsightedness

hyperopia (Hy)

condition in which a defect results in light rays focusing behind the retina rather than directly on it; causes images up close to appear blurry; farsightedness

myopia (My)

myopia (My)

presbyopia (Pr)

hyperopia caused by an age-related reduction of elasticity in the lens

retinal detachment

emergency condition in which the retina separates from the layer of blood vessels that supports it

strabismus

misalignment of the eyes caused by weakened eye muscles; also known as crossed eyes

esotropia

form of strabismus in which one or both eyes turn inward

exotropia

form of strabismus in which one or both eyes turn outward

vitreous floaters

common condition in which small specks, squiggly lines, or hair-like strands appear in the field of vision due to shrinkage and detachment of collagen fibers in the vitreous humor

acoustic neuroma

benign tumor arising from the auditory nerve

cholesteatoma

a cyst in the middle ear consisting of skin cells and cerumen (earwax)

deafness

loss of the ability to hear

conductive deafness

hearing impairment resulting from inadequate sound-wave conduction from the outer ear to the ossicles of the middle ear

nerve deafness

deafness resulting from damage to the cochlea or the auditory nerve; also called the sensorineural hearing loss

impacted cerumen

accumulation of cerumen (earwax) inside the ear that can lead to infection or hearing loss

Ménière's disease

chronic disorder of the labyrinth of the inner that causes vertigo, or a sensation of spinning

otalgia

pain in the ear; earache

otitis media

inflammation of the middle ear

otomycosis

a fungal infection of the external auditory canal. "Swimmers ear"

otosclerosis

hardening of the bony tissue of the middle ear

presbycusis

age related hearing loss

tinnitus

sensation of noises in the ears when no sound is present

vertigo

the sensation of dizziness

ageusia

loss of taste (gustatory loss)

anosmia

absence of the sense of smell, also called anosphrasia

dysgeusia

distortion of the sense of taste. A condition in which the gustatory sense is impaired, resulting in one of two responses: an unpleasant taste sensation where previously the taste sensation was pleasant, or the perception of a taste sensation when no stimulus is present

hyperosmia

an abnormally heightened sense of smell

hyposmia

reduced ability to smell

neuropathy

a disease of the nerves that involves pain or loss of sensation, most commonly in the extremities

fluorescein angiography

radiographic imaging of blood vessels (of the eye with fluorescing dye)

Ishihara Color Vision Test

test for color blindness in which a person looks at a number of circular patterns (called plates) made up of dots that vary in size, color, and brightness

ophthalmoscopy

visual examination of the interior of the eye

slit lamp microscopy

examination of anterior ocular structures under microscopic magnification

visual acuity test

part of an eye examination that determines the smallest letters that can be read on a standardized chart (Snellen ) at a distance of 20 feet

visual field test

measurement of the area within which objects are seen when the eyes are fixed, looking straight ahead without movement of the head

audiometry

measurement of hearing

otoscopy

visual examination of the ear

pneumatic otoscopy

procedure that assesses the ability of the tympanic membrane to move in response to a change in air pressure

tuning fork tests

screen for both function of the auditory nerve and ability of ear structures to conduct sound waves to the inner ear

precision nerve exams

A group of neurological exams in which five different kinds of responses are evaluated for abnormalities in the central and/or peripheral nervous system.

extinction

a test that determines a patient's ability to perceive sensation

graphesthesia

test in which the patient is instructed to close the eyes and identify a number or letter written on the hand with a pen

pain and light-touch sensation

test in which the patient lies supine with eyes closed and identifies an object as "sharp" or "dull" when the object is pressed against the skin

position sense

move fingers or toes passively and ask patient to indicate direction

stereognosis

ability to recognize objects by feeling their form, size, and weight while the eyes are closed

antibiotic

drug that fights or prevents bacterial infections

laser therapy

the surgical or therapeutic use of devices that generate concentrated beams of light

laser photocoagulation

procedure in which a laser is used to seal or eradicate retinal tears or leaking blood vessels in the retina

LASIK (laser in situ keratotomy)

procedure in which an ultraviolet laser is used to correct refraction errors such as myopia, hyperopia, and astigmatism

phacoemulsification (phaco)

a type of eye surgery performed to restore vision in cataract patients

surgery

treatment by manual or operative methods

cochlear implant

an electronic device that is surgically implanted in the inner ear to restore the sense of hearing

enucleation

surgical removal of the entire eyeball

keratoplasty

surgical repair of the cornea

myringotomy

Surgical incision in the tympanic membrane of the ear. This is done to insert an ear tube or to culture the ear for pus.

scleral buckle

suture of a silicone band to the sclera over a detached retina

vitrectomy

surgical removal of the vitreous humor

conjunctiva

a clear, colorless mucous membrane that lines the eyelids and covers the anterior portion of the eyeball

sclera

the fibrous outer layer of the eye that maintains the eye's shape and protects the delicate inner layers of tissue; known as the white of the eye

cornea

the transparent anterior portion of the sclera, which protects the iris and pupil and provides most of the optical power of the eye

choroid

the blood-rich enveloping coat of the eyeball

Iris

the pigmented muscular layer that surrounds the pupil

pupil

the black circular opening in the center of the iris that allows light to enter the eye

lens

a clear, curved, flexible structure that focuses images on the retina

ciliary body

encapsulates and holds in place the lens; made up of the ciliary muscle and suspensory ligaments

aqueous humor

a clear, watery fluid that gives the eyeball its shape

vitreous humor

a clear, gel-like substance that helps keep the retina in place

retina

a thin layer of tissue that lines the posterior of the eye internally; contains photoreceptors

photoreceptors

specialized light-sensitive cells that receive images from the environment and convert them into nerve impulses; rods and cones

rods

the eye's black-and-white photoreceptors; allow us to see in dim light; provide peripheral vision

cones

the eye's color receptors; responsible for giving the eye its sensitivity to colors of different hues

macula

an oval-shaped, pigmented area near the retina that contains specialized, high-density cones that are used for high-acuity vision

optic nerve

transmits the impulses from the retina to the brain to be interpreted

optic disc

the area where the optic nerve leaves the eyeball; known as the blind spot

fovea centralis

a tiny pit that contains only cones; this is the area of sharpest vision

lacrimal glands

located above the outer corner of each eye; secrete lacrimal fluid, or tears

ciliary glands

tiny sweat glands in the upper and lower margins of the eyelids; secrete a protective lubricant onto the eyeball

lacrimal canaliculi

the ducts at the inner corner of each eye; collect tears and drain them into the lacrimal sac

lacrimal sac

the enlarged upper portion of the lacrimal duct; stores tears before they are drained via the lacrimal duct

outer ear

made up of the auricle, auditory canal, and ceruminous glands

middle ear

a small, air-filled cavity within the temporal bone

inner ear

consists of the labyrinth, which houses the delicate structures that control balance and equilibrium in the body

auricle

forms the shell-shaped structure of the outer ear; known as the pinna

auditory canal

a short, narrow chamber that leads to the tympanic membrane

ceruminous glands

secrete a waxy, yellow substance called cerumen (earwax)

tympanic membrane

separates the outer and inner structures of the ear and transmits sound waves through vibrations; known as the eardrum

auditory ossicles

the three smallest bones in the body; transmit the vibratory motion of the eardrum to the fluids of the inner ear; malleus, incus, stapes