ch.5 book notes eyes

asthenopia

eyestrain (asthenia = weak condition)

blepharospasm

involuntary contraction of the muscles surrounding the eye causing uncontrolled blinking and lid squeezing

diplopia

double vision

exophthalmus

abnormal protrusion of one or both eyeballs; also spelled exophthalmus

exophthalmos

abnormal protrusion of one or both eyeballs; also spelled exophthalmos

lacrimation

secretion of tears

nystagmus

involuntary, rapid, oscillating movement of the eyeball (nystagmos = a nodding)

photophobia

extreme sensitivity to, and discomfort from, light

scotoma

blind spot in vision (skotos = darkness)

refractive errors

defects in the bending of light as it enters the eye, causing an improper focus on the retina

astigmatism

distorted vision caused by an oblong or cylindrical curvature of the lens or cornea that prevents light rays from coming to a single focus on the retina (stigma = point)

hyperopia

farsightedness; difficulty seeing close objects when light rays are focused on a point behind the retina

presbyopia

impaired vision caused by old age or loss of accommodation

accommodation

ability of the eye to adjust focus on near objects

amblyopia

decreased vision in early life because of a functional defect that can occur as a result of strabismus, refractive errors (when one eye is more nearsighted, farsighted, or astigmatic than the other), or trauma

aphakia

absence of the lens, usually after cataract extraction

blepharitis

inflammation of the eyelid

blepharochalasis

baggy eyelid; overabundance and loss of skin elasticity on the upper eyelid causing a fold of skin to hang down over the edge of the eyelid when the eyes are open (chalasis = a slackening)

blepharoptosis

drooping of the superior eyelid; usually caused by paralysis; also called ptosis

chalazion

chronic nodular inflammation of a tarsal gland, usually the result of a blocked duct; commonly presents as a swelling on the upper or lower eyelid (chalaza = hailstone)

cataract

opaque clouding of the lens causing decreased vision

conjunctivitis

inflammation of the conjunctiva; also called pinkeye

dacryoadenitis/dacryocystitis

inflammation of the lacrimal gland

diabetic retinopathy

disease of the retina in people with diabetes characterized by capillary leakage, bleeding, and new vessel formation (neovascularization) leading to scarring and loss of vision

ectropion

outward turning of the rim of the eyelid (tropo = turning)

entropion

inward turning of the rim of the eyelid

epiphora

abnormal overflow of tears caused by blockage of the lacrimal duct (epi = upon; phero = to bear)

glaucoma

group of diseases of the eye characterized by increased intraocular pressure that results in damage to the optic nerve, producing defects in vision

hordeolum

an acute infection of a sebaceous gland of the eyelid; also called a sty (hordeum = barley)

iritis

inflammation of the iris

keratitis

inflammation of the cornea

macular degeneration

breakdown or thinning of the tissues in the macula lutea, resulting in partial or complete loss of central vision

pseudophakia

an eye in which the natural lens is replaced with an artificial lens implant (pseudo = false)

pterygium

fibrous, wing-shaped growth of conjunctival tissue that extends onto the cornea, developing most commonly from prolonged exposure to ultraviolet light

retinal detachment

separation of the retina from the underlying epithelium, disrupting vision and resulting in blindness if not repaired surgically

retinitis

inflammation of the retina

strabismus

a condition of eye misalignment caused by intraocular muscle imbalance (strabismus = a squinting; hetero = other); also called heterotropia or crossed eyes

esotropia

right or left eye deviates inward, toward nose (eso = inward; tropo = turning)

exotropia

right or left eye deviates outward, away from nose (exo = out; tropo = turning)

scleritis

inflammation of the sclera

trichiasis

misdirected eyelashes that rub on the conjunctiva or cornea

distance visual acuity

measure of the ability to see the details and shape of identifiable objects from a specified distance, usually from 20 ft (6 m) using a Snellen eye chart; normal distance visual acuity is 20/20 (6/6)

fluorescein angiography

visualization and photography of retinal and intraocular vessels made as fluorescein dye, which is injected into a vein, circulates through the eye

slit lamp biomicroscopy

combination of a microscope and a narrow beam of light used to examine the eye, especially the cornea, lens, fluids, and membranes

sonography

use of high-frequency sound waves to detect pathology within the eye (e.g., foreign bodies and detached retina)

tonometry

use of a tonometer to measure intraocular pressure, which is elevated in glaucoma

blepharoplasty

surgical repair of an eyelid

cataract extraction

excision of a cloudy lens from the eye

cryoretinopexy

use of intense cold to seal a hole or tear in the retina; used to treat retinal detachment; also called cryopexy

dacryocystectomy

excision of a lacrimal sac

enucleation

excision of an eyeball

iridectomy

excision of a portion of iris tissue

iridotomy

incision into the iris (usually with a laser) to allow drainage of aqueous humor from the posterior to anterior chamber; used to treat a type of glaucoma

keratoplasty

corneal transplantation; replacement of a diseased or scarred cornea with a healthy one from a matched donor

laser surgery

use of a laser to make incisions or destroy tissues; used to create fluid passages or to obliterate tumors or aneurysms

laser-assisted in situ keratomileusis (LASIK)

a technique using the excimer laser to reshape the surface of the cornea to correct refractive error (e.g., myopia, hyperopia, and astigmatism) (smileusis = carving)

intraocular lens (IOL) implant

implantation of an artificial lens to replace a defective natural lens (e.g., after cataract extraction)

phacoemulsification

use of ultrasound to shatter and break up a cataract, with aspiration and removal

scleral buckling

urgery to treat retinal detachment by placing a band of silicone around the sclera to cinch it toward the middle of the eye and relieve pull on the retina

contact lens

small, plastic, curved disc with optical correction that fits over the cornea; used to correct refractive errors

eye instillation

introduction of a medicated solution in the eye, usually administered by a drop (gt) or drops (gtt) in the affected eye or eyes

eye irrigation

washing of the eye with water or other fluid (e.g., saline)

antibiotic ophthalmic solution

antimicrobial agent in solution; used to treat bacterial infections (e.g., conjunctivitis) and corneal ulcers

cycloplegic

agent that paralyzes the ciliary muscle and the powers of accommodation; commonly used in pediatric eye examinations

mydriatic

agent that causes dilation of the pupil; used for certain eye examinations

miotic

agent that causes the pupil to contract (mio = less)