Neuro - FA Patho Eye/Ear p520 -531 Flashcards
Most common cause of conjunctivitis?
viral is most common, esp adenovirus
Extra ocular symptom of viral conjunctivitis?
swollen preauricular node
What is astigmatism?
Abnormal curvature of cornea –> different refractive power at different axes. Correct with cylindrical lens.
Why does presbyopia happen?
dec lens elasticity, changes in lens curvature, dec strength of ciliary m
Where is the light focused, in terms of retina, in the case of hyperopia and myopia?
In hyperopia, light focused behind retina, and in myopia light is focused in front of the retina
Presbyopia leads to an issue with ?
accommodation
Bacteria causing conjunctivitis?
H. influ, Chlamydia(follicular type), N gon
Causes of Neonatal conjunctivitis?
N. gonorrhea, HSV-1, Chlamydia - neonatal
Children - Measles ( the 3Cs coryza, conjunct., cough) Reactive arthritis.(Reiter syndrome)
What happens in cataracts
Painless, often bilateral, opacification of lens , often resulting in glare and dec vision, especially at night
long use of what drugs can lead to cataracts
excess alcohol use, or prolong corticosteroid use
Congenital risk factors of cataracts
classic galactosemia, galactokinase deficiency, trisomies (13, 18, 21), ToRCHeS infections (eg, rubella), Marfan syndrome, Alport syndrome, myotonic dystrophy, neurofibromatosis 2.
Optic disc atrophy with cupping?
Glaucoma
How does Diabetes lead to lens opacification?
Inc gluc in the lens –> sorbitol via aldose reductase, and also to fructose. Both fructose and sorbitol will stimulate water influx –> osmotic cell injury, lens becomes opaque
Open angle glaucoma is more common in which patient population?
African American
Cause of secondary closed angle glaucoma?
Hypoxia from retinal disease, like DB or vein occlusion - induces vasoproliferation in iris that contracts angle
halos, rock hard eye, frontal headache are symptoms of what
Glaucoma - acute closure
Chronic closure glaucoma - symptoms?
Mostly asymptomatic, but over time can lead to CN II issues, especially loss of periph vision
which ND is associated with early onset glaucoma?
Sturge Weber
explain the pathophysio behind early onset glaucoma in sturge weber
ipsilateral leptomeningeal angioma & episcleral hemangioma –> inc IOP –> early onset glaucoma
2ndary causes of open angle glaucoma
blocked trabecular meshwork from WBCs (eg, uveitis), RBCs (eg, vitreous hemorrhage), retinal elements (eg, retinal detachment).
Diseases associated with uveitis?
systemic inflammatory disorders - sarcoidosis, rhematoid arthritis, juvenile idiopathic arthritis, PAIR (HLA-B27) arthritides
Collection of pus in the anterior chamber is seen in ?
uveitis
What causes metamorphopsia and loss of central vision?
Age related macular degeneration - distortion and scotomas
In dry macular degeneration, what collects in the eye?
—Deposition of yellowish extracellular material (“Drusen”) in between Bruch membrane and retinal pigment epithelium
What makes wet macular degeneration wet - how to tx?
n due to bleeding 2° to choroidal neovascularization.
Treat with anti-VEGF (vascular endothelial growth factor) injections (eg, bevacizumab, ranibizumab).
What is seen in this picture? what are the arrows pointing to?
DB retinopathy
retinal hemorrhages
What is this a picture of?
What are the arrows pointing to?
HTN retinopathy
macular star = red arrow (exudate)
cotton wool spots = blue arrow
What is this a picture of?
Retinal v occlusion
arrows point to engorged veins and hemorrhage
Two types of DB retinopathy and describe them
Non proliferative - damaged capillaries leak blood –> lipids and fluid seep into retina –> hemorrhages and macular edema
Proliferative - chronic hypoxia result in new blood vessel formation with then traction on the retina
Arrows in this photo point to?
crinkling of retinal tissue seen in retinal detachment
What causes retinal vein occlusion?
compression from nearby arterial atherosclerosis
What are the signs of retinal vein occlusion?
Retinal hemorrhage, venous engorgement, edema in affected areas
Which two layers of the retina separate in retinal detachment?
Seperation of the rods and cones layers (neurosensory layer) from the outer pigmented epithelium
Why the vision loss in retinal detachment?
Due to degeneration of photoreceptors
Retinal breaks are more common in patients with a history of what?
high myopia or history of head trauma
First symptoms that indicate retinal detachment?
“flashes” and “floaters” (from posterior vitreous detachment) and monocular loss of vision - like a “curtain drawn down”
secondary causes of retinal detachment?
retinal breaks, DB traction, inflammatory effusions
This sign is seen in what disease that isn’t congenital?
Central retinal a occlusion
Cherry red spot also seen in Neiman Pick and Tay Sachs
Painless, progressive vision loss beginning with night blindness (rodsaffected first). (Inherited)
Retinitis Pigmentosa
Bone spicule–shaped deposits around macula
Retinitis Pigmentosa
Enlarged blind spot and
elevated optic disc with blurred margins, is due to?
Papilledema, Inc ICP
Loss of red reflex in children due to?
in children include retinoblastoma, congenital cataract, toxocariasis.
What is a Marcus Gunn pupil?
DEC bilateral pupillary constriction when light is shone in affected eye relative to unaffected eye
How does one test for Marcus Gunn pupil?
Swinging flashlight test
Causes of Horner syndrome by neuron?
1st neuron: pontine hemorrhage, lateral medullary syndrome, spinal cord lesion above T1 (eg, Brown-Séquard syndrome, late-stage syringomyelia)
2nd neuron: stellate ganglion compression by Pancoast tumor
3rd neuron: carotid dissection (painful)
To test the left superior oblique and inf oblique musc, which direction should pt look?
Obliques go Opposite (left SO and IO tested with patient looking right)
Causes of CN III damage?
- Ischemia –> pupil sparing (motor fibers affected more than parasympathetic fibers)
- Uncal herniation –> coma
- PCom aneurysm
- Cavernous sinus thrombosis
- Midbrain stroke
Sx of CN III motor damage
ptosis, “down-and-out” gaze.
If PANS is also affected along with motor inn in CN III, what added sx do you see
diminished or absent pupillary light reflex, “blown pupil” ( along with ptosis and down and out gaze)
What disease lead to motor or PANS affected CN III
If just motor - usually vascular disease, if PANS, those fibers are on periphery and affected by compression (PComm, uncal herniation)
Sx of CN VI damage
Pupil is higher in the affected eye, head tilt
Sx of CN VI damage
Affected eye unable to abduct and is displaced medially
Infections associated with retinitis?
CMV (HHV5) (HIV/immunocompromised), Toxoplasmosis (congenital), HSV, VZV
Retinal edema and necrosis leading to a scar?
Retinitis
Cause of retinal occlusion?
Atrial fibrillation
Meyer loop is responsible for what part of retina? and what vision loss?
inferior –> Pie in the sky ( upper quadrantic anopia)
Meyer loop
- which lobe
- what vision defect
- what blood supply
- temporal
- upper quadrantic anopia
- MCA
you lesion the optic tract, what visual defect?
Homnoymous hemianopia
**** optic tract is in frontal lobe is supplied by MCA
What else can cause Homnoymous hemianopia?
LGB complete lesion
Meyer loop loops around?
Inferior horn of lateral ventricle
Sx of cavernous sinus syndrome
—presents with variable ophthalmoplegia, dec corneal sensation, Horner syndrome and occasional decreased maxillary sensation.
Cavernous sinus syndrome caused by?
2° to pituitary tumor mass effect, carotid-cavernous fistula, or cavernous sinus thrombosis related to infection.
Why do you see optic neuritis in MS?
CN II is only nerve myelinated by oligodendrocytes
What eye gets nystagmus in R-MLF lesion in L gaze?
L
Explanation: Abducting eye gets nystagmus (CN VI overfires to stimulate CN III)
When you say this patient has R INO, it means what?
R eye paralyzed
Bilateral INO seen in
MS, stroke
what neurocutaneous dz is associated with optic gliomas?
NF type 1
clinical symptom of lesions in frontal eye fields?
eyes look toward lesion
what area is associated with extraocular movement during REM sleep?
paramedian pontine reticular formation
what are the component of the outer ear
Pinna, auditory canal and eardrum
what conducts and amplify sound from ear drums to inner ear
ossicles
