Flashcards in Clinical- 7 Deck (56):
Review the eye anatomy
on yer own ya filthy animal
What is diplopia?
What causes diplopia?
misalignment of the eyes
What is opthalmoplegia?
When the extraocular muscle fxn is disrupted
How is the derp in opthalmoplegia?
You derp to the opposite direction because of unopposed action of the other muscles
What is ptosis?
What are the 2 causes for ptosis?
damage to either III (LPS) or symapathetics (sup tarsal)
Quick fire eye lesions/conditions/Sx: I will say a Sx and you tell me where the lesion is. Ready?
Total blindness of L eye
L optic n lesion
pituitary tumor/ optic chiasm lesion
L nasal hemianopia
calcified internal carotid
optic or retrobulbar neuritis
L homonymous hemianopia (2)
R optic tract lesion OR complete lesoion of the R optic radiation
L homonymous hemianopia + macular sparing
R PCA occlusion
L homonymous inferior quadrantanopia
R parietal lobe lesion
L homonymous supeiror quadrantanopia
R temporal lobe lesion
What is papilledema?
optic disk swelling due to increased intracranial pressure
What are the clinical features of papilledema?
almost always bilateral, typically doenst impair vision, no eye pain, assocaited w/just ↑ ICP Sx.
What happens in early papilledema?
retinal veins engorged; spontaneous venous pulsations absent; disk hyperemic (increased blood flow); linear hemorrhages at the disk borders; disk margins blurred
What happens in fully developed papilledema?
optic disk is elevated above the plane of the retina; blood vessels crossing the border of the disk are obscured
• Intracranial mass (urgent evaluation!)
• Venous sinus thrombosis, subarachnoid hemorrhage
• Polycythemia, endocrinopathy, hypervitaminosis A
• Pseudotumor cerebri (idiopathic intracranial hypertension)
• Congenital cyanotic heart disease
• Spinal cord tumor
What is the pathway for the pupillary light response?
light --> II --> optic tracts --> pretectal N. --> stimualtion of BOTH EWN --> PANS to ciliary gang --> ciliary m contraction
What are the 4 things to cause nonreactive pupils?
o local disease of the iris (trauma, iritis, glaucoma)
o oculomotor nerve compression (tumor, aneurysm)
o administration of a mydriatic agent
o optic nerve disorders (neuritis, M.S.)
What is light-near dissociation?
impaired reactivity to light but accomodation is fine.
What causes light-near dissociation?
neurosyphilis, diabetes, optic n disorders, tumors compressing the tectum
bilateral, small pupils and irregular and unequal
pupils will accomodate but wont react to light. no change with pilocarpine.
neurosyphilis, diabetes, pineal region tumors, MS
unilateral or bilateral, tonic pupil is larger
sluggish to react, reacts with pilocarpine, accommodation is less affected
holmes-adies (benign, often familial disorder, women more affected), ocular trauma, ANS neuropathy, degeneration of the ciliary gang
unilateral small pupil, ptosis
normal reponse to lgiht
Relative Afferent/Marcus Gunn- reactivity
1 pupil constricts less in response to direct illumination (kinda like IL optic n dmg)
What are the common etiologies of III palsy?
vasculopathy > aneurysm > trauma > neoplasm
What are the common eitologies for IV palsy?
trauma > vasculopathy > neoplasm > aneurysm
What are common etiologies for VI palsy?
neoplasm > vasculopathy > trauma > aneurysm
Where is the lesion to cause internuclear opthalmoplegia (INO)?
a lesion of the MLF
What happens if you lesion the MLF?
Since it connects III and IV, a lesion causes the uncoupleig movements where IV tell cant tell III to contract the MR muscle to move both eyes to 1 side
True or false: INO can be oveercome by caloric stimulation
What is the most common cause of INO in young adults, where its usually bilateral?
What is the most common cause of INO in the elderly, where it's usually unilatereal involvement?
Amaurosis fugax- clinical presentaiton
unilateral transient loss of vision over 1-5 mins
Amaurosis fugax- etiology
emboli from atherosclerotic lesion of the carotid bifurcation
Amaurosis fugax- complications
risk for subsequent hemispheric infarction
Amaurosis fugax- prognosis
endarterectomy+ ASA is the bestestest
Optic neuritis- Sx
unilateral impairment of visual acuity over hours-days. eye tenderness/pain. central scotoma. disk swelling. impaired constriction
Optic neuritis- etiology
demyelination. viral infection maybe. toxins maybe
Optic neuritis- associated problems
hyperintense lesions are seen in the brain in 50-70% of pts. many develop MS
Optic neuritis- prognosis
in acute demyelinating optic neuritis, visual acuity improves by 2-3 weeks with return to normal or near-normal vision
Anterior Ischemic Optic Neuropathy (AION)- Sx
sudden, painless, monocular vision loss. altitudinal visual defect common. disk swelling. have peripapillary hemorrhages.
atherosclerotic in origin, will have a smaller than normal disk
in 25% of pts, the other eye is affected in 2-4 years. Tx is UNsuccessful after the swelling resolves. usually optic atrophy.
Giant cell arteritis (GCA)- sx
artritic infarction is the most devatating complication, sudden and total vision loss, disk is pale and swollen, increased ESR and CRP, accompanied by feer, malaise, night sweats, weight loss and headahce.
GCA- age group
bilateral temporal artery biopsy, icnrease in ESR