module 8 eyes Flashcards
CN II
optic nerve
transmits visual signals to the brain
visual acuity
CN III
oculomotor nerve
superior, medial, and inferior rectus, and inferior oblique muscles
- up and out, down and out, up and in
CN IV
trochlear nerve
superior oblique muscle
- down and in
CN VI
abducens nerve
lateral recuts muscle
- lateral gaze
CN V
trigeminal nerve
sensory, corneal reflex
CN VII
facial nerve
motor: blink
corneal reflex
nerves in charge of small eye movement
III
IV
VI
lacrimal gland
lateral upper portion of eyelid, under brow.
- produces tears
lagophthalmos
eyes do not close completely
ptosis
eyelid drooping
- covers upper portion of iris or pupil
corneal arcus
lipid deposit around iris
anisocoria
pupils different sizes
miosis
pupillary constriction
- iridocyclitis
- miotic eye drops
- opioid abuse
mydriasis
pupillary dilation
- iridocyclitis
- mydratic or cycloplegic drops
- midbrain lesions or hypoxia
- oculomotor (CN III) damage
- acute-angle glaucoma
- stimulant use; cocaine, amphetamines
failure to respond with light stimulus
- iridocyclitis
- retinal degeneration
- CN II destruction
- midbrain synapses or CN III
- impairment of efferent fibers (PSNS), sphincter pupillae muscle
- mydriatics
- brain herniation
argyll robertson pupil
bilateral, miotic, irregularly shaped pupils that fail to constrict with light, but retain constriction with convergence
- may or may not be equal in size
- neurosyphilis
- lesions in midbrain
Anisocoria
unequal pupil size
- congenital: 20%
- local eye meds
- unilateral SNS or PSNS pathway destruction
Iritis constrictive response
acute uveitis, commonly unilateral
- constriction of pupil accompanied by pain and reddened eye, especially adjacent to iris
oculomotor nerve damage CNIII
pupil dilated and fixed
- eye deviated laterally and downward
- ptosis
Adie pupil (tonic pupil)
affected pupil dilated and reacts slowly or fails to react to light, responds to convergence
- impairment of postganglionic PSNS innervation of sphincter pupillae muscle
- ciliary malfunction
- often accompanied by diminished tendon reflexes
exophthalmos patho
bulging of eye anteriorly out of orbit
- inc. in volume of orbital contents
- Graves disease: abnml CT deposition in orbit and extraocular muscles
- when unilateral consider retro-orbital tumor
exophthalmos subjective
change in eye position or valsalva maneuver
exophthalmos objective
apparent eye protrusion, lids do not reach pupil
episcleritis patho
inflammation of the superficial layers of the sclera anterior to the insertion of the rectus muscles
- Simple: intermittent episodes of moderate to severe inflammation. 1-3 month intervals, lasting 7-10 days, and resolving after 2-3 weeks
- Nodular: prolonged attacks of inflammation, typically more painful than simple
episcleritis subjective
acute onset of mild to moderate discomfort or photophobia
- painless injection (redness) and/or watery discharge without crusting
episcleritis objective
diffuse or localized redness of the bulbar conjunctiva
purplish elevation of a few mm.
watery discharge
band keratopathy patho
deposition of calcium in the superficial cornea
- most common in pt with chronic corneal disease
band keratopathy subjective
dec. in vision as deposition progresses
foreign body sensation and irritation
band keratopathy objective
line just below the pupil, passes over the cornea rather than around the iris as with arcus senilis
- horizontal grayish bands interspersed with dark areas that look like holes
corneal ulcer patho
disruption of the corneal epithelium and stroma
- CT disease or systemic vasculitic disorder
- infection: viral or bacterial
- extreme dryness
corneal ulcer subjective
pain photophobia hx of wearing contacts blurry vision feeling that something is in the eye
corneal ulcer objective
visual acuity affected variably, depending on location
inflammation and erythema of the lids and conjunctiva
purulent exudates
ulcer often round or oval and the border sharply demarcated, base appearing ragged and gray
strabismus patho
both eyes do not focus on an object simultaneously but can focus with either eye
strabismus subjective
poor vision
may have sudden onset of double vision
report of eye deviation
strabismus objective
extraocular muscle impairment: eye will not move in the direction controlled by that muscle
detected by the cover-uncover test
horner syndrome patho
interruption of SNS to the eye
- congenital, acquired, or hereditary
- lesion of primary neuron, stroke, trauma
Horner syndrome triad
ipsilateral miosis
mild ptosis
loss of hemifacial sweating
Horner syndrome subjective
s/s depend on underlying cause
horner syndrom objective
ptosis is subtle: note amount of iris seen superiorly
pupil on affected side round and constricted
Aniscoria (size difference) greated in darkness
affected pupil dilates more slowly than nml pupil
dry skin on same side of face as affected pupil
cataract patho
opacity in lens
- denaturation of lens protein caused by aging
- peripheral: hypoparathyroidism
- Meds: steroids
- Congenital: maternal infections, fetal insult during 1st trimester.
cataract subective
cloudy or blurry vision faded colors headlights, lamps, or sunlight appear too bright halo around lights poor night vision or double vision frequent Rx changes
cataract objective
cloudiness of the lens
diabetic retinopathy (nonproliferative) patho
dot hemorrhages or microaneurysms and the presence of hard and soft exudates
- hard: lipid transudation through incompetent capillaries
- soft: infarction of the nerve layer
diabetic retinopathy nonproliferative subjective
asymptomatic in initial stages
blurred vision, distortion, or visual acuity loss in more advanced stages
diabetic retinopathy nonproliferative objective
on ophthalmoscopic examination
- blood vessels with balloon-like sacs
blots of hemorrhages on the retina itself
tiny yellow patches of hard exudates
diabetic retinopathy proliferative patho
development of new vessels as result of anoxic stimulation
- vessels grow out of retina toward vitreous humor
diabetic retinopathy proliferative subjective
generally asymptomatic
floaters
blurred vision
progressive visual acuity loss in advanced stages
diabetic retinopathy proliferative objective
visualization of these vessels may require change in the lens setting
- vitreous hemorrhage may also be seen, can obstruct view of retina
glaucoma patho
disease of the optic nerve where the nerve cells die
- usually due to high intraocular pressure
- Acute angle: occur acutely with dramatically elevated pressure if iris blocks exit of aqueous humor from anterior chamber
- Open angle: caused by dec. aqueous humor absorption
- > inc. resistance and painless buildup of pressure in the eye
glaucoma subjective
open-angle:
- gradual loss of peripheral vision over a period of years
Acute:
- intense ocular pain, blurred vision, halos around lights, red eye, dilated pupil
Occasionally: abd. pain, N/V
glaucoma objective
optic nerve damage can clearly be seen during dilated eye exam and produces a characteristic appearance of the optic nerve ( increased cupping)
- visual field test may show los of peripheral vision
