Diseases of Visual Pathways/Dysfunction

Question 1

What is anisocoria & it is present in what percent of the population?

Answer 1

(unequal pupil size) variant of normal

20%

Question 2

What are the components of an eye exam?

Answer 2

• V. A. testing
• V. F. testing
  
  • confrontation
  • amsler grid
• color perception & saturation
• pseudochromatic plates
• red cap test

Question 3

Describe the pathway of the pupilary reflex

Answer 3

• affarent (optic nerve taking info of light source to midbrain)
  
  • synapse in pretectal nucleus
  • following neuron synapses in CN III nucles
    
    • only one nucleus - shared btw eyes, which is why we get consensual pupilary response
  • CN III exits anterior brains stem with parasympathetic fibers
    
    • synapse in ciliary ganglion
    • final neruron innervates the pupil

Question 4

How do we assess ocular motility?

Answer 4

cardinal fields of gaze

Question 5

What is the term for misalignment of the eyes?

Answer 5

strabismus

Question 6

What is the term for limitation of movement in one eye?

Answer 6

duction

Question 7

What is the term for limitation of conjugate gaze?

Answer 7

version

Question 8

Describe the sympathetic innervation of the eye & face

Answer 8

• (origination sympathetic innervation eye & face) - hypothalamus
• descend to midbrain & pons - terminate C8-T2 & synapses in iteromediolateral cells of spinal cord
• exits central nervous system T1(still preganglionic) & move through sympathetic chain to synapse at superior cervical ganglion (C3/C4)
  
  • these postganglionic fibers are pseudomotor & vasomotor fibers
    
    • follow external carotids (innervate sweat glands & vessels of the face)
    • follow internal carotids (cavernous sinus; join CN VI into orbit & exit as long ciliary nerves)

Question 9

What is the difference between true diplopia & monocular diplopia?

Answer 9

• true diplopia
  
  • two separate images, one of which disappears when either eye is closed
• monocular diplopia
  
  • not eliminated by closing the fellow eye
  • refractive problem, dry eye, or cataract

Question 10

Vertical diplopia is associated with palsy of what CN?

Answer 10

CN IV

Question 11

Horizontal diplopia is associated with palsy of what CN?

Answer 11

CN VI

Question 12

What should you do if a patient comes in complaining of double vision?

Answer 12

thorough neurologic history & physical

Question 13

What type of ptosis is seen with a CN III palsy?

Answer 13

complete ptosis

Question 14

An eye cannot move in which direction in a CN III Palsy?

Answer 14

cannot adduct or look superior

Question 15

An eye cannot move in which direction in a CN IV Palsy?

Answer 15

cannot depress

Question 16

An eye cannot move in which direction in a CN VI Palsy?

Answer 16

cannot abduct

Question 17

What is the term for optic disc elevation is both eyes?

Answer 17

pipilledema

Question 18

What is the differential diagnosis of papilledema?

Answer 18

brain tumor / space occupying lesions

idiopathic intracranial hypertension (PTC)

cerebral trauma or hemorrhage

meningitis/encephalitis

dural sinus thombosis

Question 19

What does papilledema look like ona fundoscopic exam?

Answer 19

the nerve fiber starts to cover the vein on the side

& the disc appear larger than it should

(looks like an innertube)

Question 20

What arethe optic nerve disorders that are localized to the globe?

Answer 20

• Papillitis
• optic neuritis
• ischemic optic neuropathy
  
  • nonarteritic
  • arteritic ion
• amaurosis fugax (transient monocular blindness)
• optic atrophy

Question 21

What bacterial agent can cause papilitis?

Answer 21

• Cat Scratch Disease (bartonell henslae)
• Toxoplasmosis
• Treponema Pallidum

Question 22

What is the term for any visual field defect?

Answer 22

scotoma

Question 23

What is the term for los sof half the visual field?

Answer 23

hemianopia

Question 24

What is the term for similar right or left visual field loss?

Answer 24

homonymous hemianopia

Question 25

What is the term for loss of temporal visual field in both eyes?

Answer 25

bitemporal (heteronymous) hemianopia

Question 26

What is a common cause of bitemporal heteronymous hemianopia?

Answer 26

pituitary lesion

Question 27

Identify where the lesion is occurring for locations 1-8 & the resulting visual impairment

Answer 27

1. Optic nerve lesion 1. complete loss of visual field of one eye 2. Optic nerve lesion close to chiasm 1. Superior temporal cut in oposite eye 3. Lesionis optic chiasm 1. true bitemporal visual field defect 4. Lesion in optic tract 1. homonomous hemianopsia (loss of same field) 5. Temporal defect 1. "pie in the sky" 6. lesion in lateral geniculate nucleus 1. homonomous hemianopais (same as 4) 7. Parietal defect 1. inferior field defect 8. Occipital defect 1. usually some sparing of macular visual field d/t multiple bood supplies

Question 28

What is Charles Bonnet Syndrome?

Answer 28

Visual release hallucinations people who have very good vision for most of their lives & then lost it (macular degeneration or trauma etc.) the see things

Question 29

In what situations do patients with normal vision develop visula hallucinations?

Answer 29

dementia

Question 30

What is cognitive visual loss? This can be a symptom of what condition?

Answer 30

not seeing well in spite of normal eye exam difficulty with object recognition or inability to concentrate on more than one visual stimulus at the same time Think dementia / Alzheimers

Question 31

How do you test for visual dementia?

Answer 31

clock drawing test