Visual Fields

Question 1

! Rule out VF defect
! Document VF defect
! Localize pathology in visual pathway ! Monitor disease process over time

Answer 1

Reasons for performing perimetry

Question 2

superior 60
inferior 75
temporal 100
nasal 60

Answer 2

normal limits of vf

Question 3

!  Corresponds to the optic nerve 
!  15 ̊ temporal to point of fixation
!  1.5 ̊ below horizontal meridian
!  Diameter:
      !  5 ̊ horizontal 
      !  7 ̊ vertical


Answer 3

physiologic blind spot

Question 4

VF examination strategies

Answer 4

kinetic perimetry

Question 5

! Tests differential light sensitivities of specific retinal locations
on a fixed grid pattern
! Spacing between points varies on type of examination area

Answer 5

static perimetry

Question 6

! Grey scale
! Decibel sensitivity plot
! Total deviation numerical & probability plot
! Numerical plot in decibels
! Compares sensitivity at each point to normal population of similar age
! Pattern deviation numerical & probability plot
! Adjusts for generalized depression or elevation of VF

Answer 6

automated static perimetric plots

Question 7

! Fixation losses
! False positives
! False negatives

Answer 7

reliability indices

Question 8

!  30-2
!  24-2
!  10-2
!  Macular
!  Nasal step: additional 12 locations up to 50 degrees nasal

Answer 8

humphrey vfa

Question 9

! Generalized reduction in retinal sensitivity

Answer 9

vf defect depression

Question 10

! Focal area of reduced sensitivity surrounded by an area of
normal sensitivity
! Absolute : defect persists when maximum stimulus is used (ie. blind spot)
! Relative: defect present to weaker stimulus, but disappears with brighter stimulus

Answer 10

scotoma vf defect

Question 11

where are the axons in the optic nerve

Answer 11

behind the orbit and

near the chiasm

Question 12

! Containscrossed(nasal)anduncrossed (temporal) fibers
! Typically situated directly above sella turcica
! Superior: hypothalamus and floor of third ventricle
! Inferior:pituitarygland
! Lateral: IC A and cavernous sinus

Answer 12

chiasmal anatomy

Question 13

! Pituitarytumorinvolves

chiasm first

Answer 13

central: directly over sella

Question 14

! Pituitarytumorinvolves

chiasm first

Answer 14

prefixed: anterior to sella

Question 15

! Pituitary tumor damages optic nerve(s) first

Answer 15

post fixed: posterior to sella

Question 16

! Extend from chiasm to LGB
! Fibers from temporal half of ipsilateral eye and nasal half
of contralateral eye
! Visual fields will produce homonymous hemianopia ! Typically incongruous

Answer 16

optic tracts

Question 17

!  Relaynucleus
!  Positionedalonglateralaspectof
midbrain
!  Further organization of fibers
!  VF lesions will be hemianopic (congruous or incongruous)

Answer 17

lateral geniculate body

Question 18

! SuperiorVF
! MeyersLoop:temporallobe
! Temporal lobe lesions: “pie in thesky”

Answer 18

inferior fibers (optic radiations)

Question 19

! InferiorVF
! Loopposteriorlythrough parietal lobe
! Parietallobelesions:“pieonthe floor”

Answer 19

superior fibers

Question 20

! Medial aspect of occipital lobe ! Significant input from macula
! Central 30 degrees occupy 83% of the striate cortex

Answer 20

visual cortex

Question 21

blood supply of optic chiasm

Answer 21

circle of willis

Question 22

blood supply of visual cortex

Answer 22

! Posterior cerebral artery

! Middle cerebral artery

Question 23

!  Unilateral
!  Invades vertical hemianopic line
!  May respect horizontal line d/t separation of fiber bundles !  Complete/partial vision loss
!  Color vision defect
!  RAPD

Answer 23

lesions of optic nerve clinical findings

Question 24

!  Optic neuritis
!  Trauma
!  Space occupying lesion (adenoma, glioma, meningioma) !  Ischemic optic atrophy (NAION, AION)
!  Papilledema
!  Nutritional/toxic insult
!  Glaucoma

Answer 24

causes of lesions of optic nerve

Question 25

!  Vision loss
!  Typically painless
!  Progressive
!  Bilateral asymmetric
!  Headache possible
!  Stretching of diaphragma sella

Answer 25

chiasmal disease

Question 26

!  Signs
!  +/- VA loss
!  VF defect
!  Optic atrophy
!  APD
!  Dyschromatopsia
!  +/- endocrine dysfunction
!  Diplopia: if adjacent cavernous sinus is involved

Answer 26

chiasmal disease signs

Question 27

!  Pituitary adenoma
!  Suprasellar meningioma !  ICA aneurysm
!  Optic nerve glioma
!  Uncommon: !  Trauma
!  Inflammation

Answer 27

chiasmal disease: etiology

Question 28

!  Causes: compressive disease
!  Aka junctional scotoma due to
compression of Von Willebrand’s Knee
!  Due to post-fixed chiasm
!  Clinical findings
!  Ipsilateral RAPD
!  +/-diplopia
!  Ipsilateralcentralscotoma
!  Contralateralsuperiortemporaldefec

Answer 28

anterior chiasmal syndrome

Question 29

! Pre-fixed chiasm
! Macular fibers cross posteriorly in chiasm
! Tumor impinges on posterior chiasm and optic tracts
! Clinical findings
! Central bitemporal hemianopic defects (nasal macular fibers) ! Homonymous hemianopia due to optic tract compression

Answer 29

posterior chiasmal syndrome

Question 30

! Causes
! Suprasellar aneurysm
! Pituitary gland tumors
! Suprasellar meningioma and glioma
! Third ventricular dilation due to obstructive hydrocephalus
! Clinical presentation ! Bitemporal hemianopia ! Bilateral optic atrophy

Answer 30

middle chiasmal syndrome

Question 31

! Causes
! Distention of 3rd ventricle causing pressure on each side of
chiasma
! ICA aneurysm
! Clinical findings
! Binasal hemianopia ! Partial optic atrophy

Answer 31

lateral chiasmal lesions

Question 32

! Acromegaly: prominent brows/nose/chins
! Cushing Syndrome: moon face, truncal obesity, buffalo hump ! Galactorrhea
! Amenorrhea
! Decreased libido, infertility

Answer 32

endocrine dysfunction

Question 33

! Band pallor: common
! Diffuse pallor
! APD
! Dyschromatopsia

Answer 33

optic atrophy

Question 34

! MRI with contrast
! Neurosurgical referral ! Endocrine workup
! Monitor visual fields
! Every 4-6 months until stabilization, then annually

Answer 34

chiasmal disease manaement

Question 35

! Homonymous: nasal VF of one eye and temporal VF of fellow eye
! Congruous: nasal and temporal defects closely resemble each other
! Fibers posterior to chiasm become more segregated in terms of what part of the VF they represent
! Decreased VA not common unless lesion also involves optic nerve or occipital lobes
! Usually due to cardiovascular disease

Answer 35

post chiasmal disease

Question 36

!  Causes:
!  Tumors
!  Ischemic stroke
!  Aneurysms of superior cerebellar or PCA
!  Clinical findings:
!  +/- congruous hemianopia

Answer 36

optic tract lesions

Question 37

!  Causes:
!  Vascular occlusions
!  Primary & secondary tumors 
!  Trauma
!  Clinical findings:
!  Incomplete incongruous quandranopsias 
!  Neurologic deficits predominate


Answer 37

lesions of optic radiations

Question 38

!  Incongruous “pie in the sky”
!  Affects Meyer’s Loop: inferior retinal fibers
!  Neurologic symptoms !  Seizures
!  Hemiparesis
!  Hemisensory loss
!  Aphasia

Answer 38

temporal lobe lesions

Question 39

!  Incongruous “pie on the floor”
!  Affects superior retinal fibers
!  Neurologic symptoms !  Hemiplegia
!  Hemisensory loss
!  Visual neglect
!  Aphasia

Answer 39

parietal lobe lesion

Question 40

! Congruous homonymous hemianopia with macular sparing

Answer 40

middle cerebral artery infarct

Question 41

! Congruous homonymous macular defect

Answer 41

posterior cerebral artery infarct

Question 42

! Incongruous homonymous hemianopia
! Fibers segregated into R & L side of visual pathway
! Contralateral APD because temporal VF is 40% larger than nasal VF
! Band optic atrophy

Answer 42

optic tracts

Question 43

! Congruous

! Very small lesion and very difficult to isolate

Answer 43

LGN post chiasmal vf defects

Question 44

! Incongruous
! Pie-shaped superior homonymous hemianopia ! Seizures and hallucinations common
! Neurologic symptoms predominate

Answer 44

temporal lobe post chiasmal vf defect

Question 45

! Congruous, complete or incomplete

! Neurologic symptoms predominate

Answer 45

parietal lobe post chiasmal vf defect

Question 46

! Absolute congruity
! Superior and inferior fibers completely separated ! Extreme respect for vertical and horizontal midline
! Homonymous central or macula-sparing defects ! Absence of neurologic symptoms

Answer 46

occipital lobe post chiasmal vf defect