ch 15 Jarvis Physical Examination & Health Assessment

eye anatomy

cornea: transparent, curved membrane on the front of the eye.

sclera: white out layer protective covering of eye.

aqueous humor: fills the cavity between the cornea and the lens.

iris: colored part of the eye, which covers the lens. Functions as a diaphragm, changing pupil size.

pupil: hole in center of iris that lets light through to fall on the lens. The iris opens and closes the pupil depending on the intensity of light.

lens: focuses light. Under muscle control (ciliary body), it can move forward and backward, and also get thinner or fatter to change its focal length.

retina: surface of the inside of the eye, which is covered with light-sensitive receptor cells.

fovea: had highest density of photoreceptors can be found in the fovea; the fovea is the center of your visual field. Located at the center of the macula on the ocular fundus

accommodation

adaptation of the eye for near vision by increasing the curvature of the lens.

anisocoria

unequal pupil size

arcus senilis

gray-white arc or circle around the limbus of the iris that is common with aging

Argyll Robertson pupil

pupil does not react to light; does constrict with accommodation

astigmatism

refractive error of vision due to differences in curvature in refractive surfaces of the eye (cornea and lens)

A-V crossing

crossing paths of an artery and vein in the ocular fundus

bitemporal hemianopsia

loss of both temporal visual fields

blepharitis

inflammation of the glands and eyelash follicles along the margin of the eyelids

cataract

opacity of the lens of the eye that develops slowly with aging and gradually obstructs vision

chalazion

infection or retention cyst of a meibomian gland, showing as a beady nodule on the eyelid

conjunctivitis

inflammation of the conjunctiva (pink eye)

cotton wool area

abnormal soft exudates visible as gray-white areas on the ocular fundus

cup-to-disk ratio

ratio of the width of the physiologic cup to the width of the optic disc, normally half or less

diopter

unit of strength of the lens settings on the ophthalmoscope that changes focus on the eye structures

diplopia

double vision

drusen

benign deposits on the ocular fundus that show as round yellow dots and occur commonly with aging

ectropion

lower eyelid loose and rolling outward

entropoin

lower eyelid rolling inward

exophthalmos

protrusion of the eyeball

fixation

very rapid movements to put the target eye is "fixed" on back on the fovea when head is turning.

fovea

area of keenest vision at the center of the macula on the ocular fundus

consensual

both sides of the body respond equally to the stimulus (ex. both pupils dilate the same)

Glaucoma

a group of eye diseases characterized by increased intraocular pressure

hordeolum (stye)

red, painful pustule that is a localized infection of hair follicle at eyelid margin

lid lag

abnormal white rim of sclera visible between the upper eyelid and the iris when a person moves the eyes downward

macula

round darker area of the ocular fundus that mediates vision only from the central visual field

microaneurysm

abnormal finding of round red dots on the ocular fundus that are localized dilations of small vessels

miosis

constricted pupils

mydriasis

dilated pupils

myopia

nearsightedness, refractive error in which near vision is better than far vision

nystagmus

involuntary, rapid, rhythmic movement of the eyeball

optic atrophy

pallor of the optic disc due to partial or complete death of optic nerve

optic disk

area of ocular fundus in which blood vessels exit and enter

papilledema

stasis of blood flow out of the ocular fundus; sign of increased intracranial pressure

presbyopia

decrease in power of accommodation that occurs with aging

pterygium

triangular opaque tissue on the nasal side of the conjunctiva that grows toward the center of the cornea

ptosis

drooping of upper eyelid over the iris and possibly covering the pupil

red reflex

red glow that appears to fill the person's pupil when first visualized through the ophthalmoscope

strabismus

crossed eyes

xanthelasma

soft, raised yellow plaques occurring on the skin at the inner corners of the eyes

opthalmoscope

instrument used to examine the interior of the eye

PERRLA (CN II, CN III)

P - Pupils should be clear

E - Equal in size and between 3 to 5 cm

R - Round in shape

R - Reactive

L - to Light both directly and consensually when a light is directed into one pupil and then the other

A - Accommodation of the pupils when they dilate to look at an object far away and then CONVERGE and CONSTRICT to FOCUS on a near object.

*cannot check accommodation on unconscious patient

Snellen chart

used to measure visual acuity. (patient usually stand 20ft away from chart)

20/20 is normal

20/30-you can read at 20 ft what the normal eye can see at 30 ft

confrontation test

gross measure of peripheral vision. It compares the person's peripheral vision with your own (one eye covered, wiggling fingers)

Corneal Light Reflex (Hirschberg Test)

reflection of the light on the corneas, should be in the exactly same spot on each eye

assymetry indicates deviation in alignment from eye muscle weakness or paralysis

diagnostic positions test (CN III, CN IV, CN VI)

6 cardinal gazes: normal response is parallel tracking of the object with both eyes

when eye movement is not parallel: indicates weakness of an EOM or dysfunction of cranial nerve innervating it (CN III, IV, VI)

papillary light reflex (CN II, CN III)

dark room, patient looks into distance while light is shined from side of eye. Both pupils should constrict at same time (consensual)

accommodation test

patient looks at distant object (pupils dilate) patient looks at close object (pupils constrict)

lacramal apparatus

provides constant irrigation to keep the conjunctiva and cornea moist and lubricated.

lacrimal gland

gland located in the upper outer region above the eyeball that secretes tears

inner canthus

The corner of the eye where the upper and lower eyelids meet, tears drain into