CN 1,2,3,4,6 Examinations Flashcards
Normal disc to cup ratio
2:1
Normal retina color? Physiological cup color?
Macula?
Red/orange
Pale
Dark
Arterial to venous ratio in eye
2:3
When might you find an elevated disc with blurred margins?
Optic neuritis/papillitis
What would the Disc, retina, vessel findings be in papilledema (due to increased ICP)?
Disc: elevated, blurred disc margins and vessels engorged
Retina: flame retinal hemorrhage close to disc
Vessels: engorged and tortuous
BILATERALLY except F-K
What two conditions have elevated and blurred disc
Papilledema and optic neuritis
How would you differentiate papilledema vs optic neuritis?
In papilledema: NO VISUAL complaint/loss
Optic neuritis: inflammation of nerve causes visual complaint/loss
-early and quick!
Ophthalmoscopic exam findings of disc, retina, vessels seen in optic atrophy?
Disc: sharp clear margins with an overall pale white color
Retina: normal
Vessels: A: attenuated V: normal
Is vision affected with optic atrophy?
Yes
Ophthalmoscopic findings in tay-Sachs?
Dark cherry red spot in place of the macula lutea
Ophthalmoscopic findings for disc, retina, vessels in glaucoma?
Recall: intraOCULAR pressure increase
Disc: large cup to disc ratio (norm 1:2), vessels discplaced peripherally, pale white, pigment surrounding disc
Retina: normal
Vessels: normal
Ophthalmoscopic findings in retinal detachment. Disc, retina, vessels
Disc: normal
Retina: gray elevation with folds in detached section
Vessels: tortuous and elevated over detached retina
S/s of retinal detachment
Flashes/floaters or veil/shadow/curtain across vision
Ophthalmoscopic exam findings in non-proliferative diabetic retinopathy: disc, retina, vessels
Disc: Normal
Retina: many scattered exudates/retinal hemorrhages
Vessels: mild dilation of retinal veins
Ophthalmoscopic exam findings in proliferative diabetic retinopathy: disc, retina, vessels
Disc: new vessels growing on disc
Retina: numerous hemorrhages, new vessels at superior disc margins
Vessels: dilation of veins
Ophthalmoscopic exam findings for hypertensive retinopathy; disc, retina, vessels
Disc: clear outline
Retina: exudates and flame hemorrhage
Vessels: narrowed, increased tortuosity, copper wiring, AV nicking
CN 3,4,6 exam process
- inspection
- accommodation (3)
- corneal light reflex (3,4,6)
- pupillary light reflex (2,3)
- 6 cardinal fields of gaze (3,4,6)
MC causes of unilateral and bilateral ptosis
Unilateral: horners syndrome, pancos tumor, stroke, Bell’s palsy, TIA, stroke, cluster HA/migrane
Bilateral: MG
What CN does accommodation test
3
What 3 things should occur during accommodation test
Convergence (medial recti) Pupilloconstruction (parasympathetic fibers) Lens thickening (ciliary muscle-unnoticeable—allows focus)
CN tested during corneal light reflex
3,4,6
Process in corneal light reflex test
Patient focus on distant object and shine lights t nasal bridge (12 inches)
Eye should reflect symmetrically
CN tested with pupillary light reflex
CN 2,3
CN tested with cardinal fields of gaze
3,4,6
Explain each muscle tested in each eye during cardinal fields of gaze
See picture on slide 68
CN 3 abnormals
Ptosis
Mydriasis (pupil dilation)
Eye deviated down and out
MC cause of CN 3 abnormals
Ischemia and aneurysm
What CN is affected during: ptosis
CN 3
What CN is affected during: mydriasis
CN3
What CN is affected during: eye deviation down and out
CN3
Abnormals with CN 4
- difficulty looking down and in
- patient commonly tilts head to opposite shoulder (minimize diplopia)
MC cause of damage to CN 4
Head trauma
What CN is affected during: difficulty looking down and in
CN4
What CN is affected during: when patient tilts head to R shoulder
L CN4
Abnormals with CN 6
- eye deviates medically
- difficult looking laterally
CN6 damage usually caused by
Neoplasms
Trauma
Microvascular neuropathy
MC etiologies
What CN is affected during: deviation of eye medically
6
What CN is affected during: issues looking laterally
6
Nystagmus
Involuntary eye oscillations
-may occur side/side, up/down, or circular
Nystagmus that is fast and represents saccadic movement. Lobe?
Frontal
Nystagmus slow represents following movement. Lobe?
Occipital
Where is nystagmus common that is not pathological
“End point”
