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Visual Fields – An Interactive Approach: COURSE OUTLINE
Kelly H. Thomann, OD, FAAO
Nancy Wong, OD, Ph D, FAAO
I.
Overview of visual field & defect quantifiers
1. Monocular
a. Superior, inferior, temporal, nasal
2. Binocular
a. Shape
b. Dimensions
3. Classification of visual field defects
a. Density, size, position, shape, location, laterality, equality
II.
Perimetric devices
A. Kinetic
1. Tangent screen, Goldmann, Humphrey with kinetic testing,
Octopus kinetic
B. Static
1. Humphrey, Dicon, Octopus
III.
Visual field testing indices, paradigms, strategies
A. Reliability indices
1. Fixation loss
2. False positives
3. False negatives
4. Test duration
B. Test paradigms and strategies
1. Full threshold
2. SITA
1. Standard
2. Fast
3. SWAP
C. Automated static perimetric plots
1. Grey scale
2. Decibel sensitivity plot
3. Total deviation numerical plot & total deviation probability
plot
4. Pattern deviation numerical plot & pattern deviation
probability plot
IV.
Classification of visual field defects
A. Density
1. Absolute – no sensitivity
2. Relative – depressed sensitivity
B. Size / Extent
1. Partial
2. Total
C. Shape
1. Hemianopia
D.
E.
F.
G.
V.
2. Quadranopia
3. Altitudinal
4. Sectorial vs. Non-Sectorial Scotoma
Position
1. Superior vs. Inferior
2. Right vs. Left
Location
1. Central (<30 degree radius from fixation)
2. Para- or Peri-central
3. Peripheral (>30 degree radius from fixation)
Laterality
1. Unilateral
2. Binocular (Homonymous vs. Heteronymous)
Equality
1. Congruous
2. Incongruous
Visual pathways and territories
A. Retina
1. Topography
1. Papillomacular bundle – Ganglion cells arising from the
fovea represent the central 2 degrees of the visual
field
2. Arcuate
bundle
–
Fibers
arising
from
the
superotemporal and inferotemporal retina and exiting
at the poles of the optic nerve
3. Nasal radial bundle – Fibers nasal to the optic nerve
head
2. Field defects based upon retinal topography:
1. Sharp borders
2. Respect horizontal meridian
B. Optic Nerve
1. Pre-chiasmal
a) Orbital section extends from the globe to the optic
foramen
b) Intra-canalicular portion extends through the optic canal
c) Intra-cranial section extends from the posterior optic
canal to the anterior chiasm
2. Field defects based upon optic nerve anatomy
C. Chiasm
1. Optic nerves converge over the sella turcica to form the
chiasm
2. Left and right visual worlds become separated here
3. Nasal retinal fibers decussate at the chiasm
4. Temporal retinal fibers remain ipsilateral
5. The pituitary gland is located beneath the chiasm
6. Chiasmal VF defects are dependent upon anatomy
a) Post-fixed chiasm
b) Fixed chiasm
c) Pre-fixed chiasm
D. Optic tract
1. Field
defect
characteristics:
Hemianopsia,
incongruous
2. Pupil fibers: Relative afferent pupil defect
3. Optic disc pallor; “bow-tie atrophy”
typically
E. Lateral geniculate nucleus
1. Defect types:
1. Incongruous/congruous hemi or quadrantanopsia
2. Sectorial hemianopsia
3. Sectorial hemianopsia with midline sparing
F. Temporal Lobe
1. Meyer’s loop
2. Field defect characteristics:
1. Superior, homonymous
2. Denser above horizontal meridian
3. Functional overview
1. Hearing, memory, meaning, language
2. Emotion, learning
3. Interpret and process auditory stimuli
4. Visual perception
5. Motor, sensory
4. Dominant vs. Non-dominant hemisphere functions
1. Dominant:
a. Language/speech perception
b. Verbal and visual memory
2. Non-dominant:
a. Neglect
b. Visual memory
c. Tonal sequences, musical abilities
d. Speech
G. Parietal Lobe
1. Pathway and corresponding visual field defects
a. Fibers from the inferior retina merge with fibers from
the superior retina
b. Hemianopic field defects which are denser inferiorly
2. Functional overview
a. Integration of sensory function (cognition)
b. Construct of spatial coordinate system
3. Dominant vs. Non-dominant hemisphere functions
a. Dominant:
1. Right-left orientation
2. Verbal reception
3. Perception of tactile stimuli
4. Ability to calculate
5. Gerstmann’s syndrome
b. Non-dominant – visual spatial function
1. Possible deficits:
a. Contralateral neglect
b. Constructional apraxia
c. Anosagnosia
d. Impaired drawing ability
4. Optokinetic nystagmus
H. Occipital Lobe and Visual Cortex
1. Pathway:
1. Macular fibers are strongly represented in the
posterior pole of the visual cortex
2. Peripheral field fibers project to the anterior portions
of the occipital cortex:
a) Inferior retinal fibers project to the cortex lying
superior to the calcarine fissure
b) Superior retinal fibers project to the striate cortex
which lies inferior to the calcarine fissure
2. Functional overview:
1. Processing of visual information
2. Responsible for visual reception and visual association
3. Signs of dysfunction:
1. Achromotopsia
2. Visual agnosia
3. Associative agnosia
4. Visual form agnosia
5. Prosopagnosia
VI.
Neuro-imaging Studies
A. Reference Planes
1. Reading imaging studies
B. Imaging planes
1. Axial (Transverse)
2. Coronal
3. Sagittal
C. Imaging Types
1. Computed Tomography (CT)
2. Magnetic Resonance Imaging (MRI)
1. T1 Weighted
2. T2 Weighted
3. Inversion Recovery
a. Fat suppression
b. Fluid Attenuated Inversion Recovery (FLAIR)
D. Indications for CT scan:
1. Orbital disorders
2. Sinus disorders
3. Lacrimal disorders
4. Acute brain hemorrhage
5. Contraindication to MRI
E. Indications for MRI
F. Imaging the visual pathway, key locations:
1. Orbit
2. Cavernous sinus
1. Key anatomic points
2. Best imaging type, section, view
3. Chiasm
1. Key anatomic points
2. Best imaging type, section, view
4. Visual pathway
5. Retrogeniculate pathway
6. Cortex
VII.
Visual field case presentation and analysis
A. 15 Cases with corresponding visual fields will be presented
1. Based on the presented defects, participants localize the
lesion along the visual field pathway on topographical
worksheets
2. Participants will be asked to characterize each defect
3. Participants will be asked to provide possible anatomic
locations for the lesion
VIII. Comparison of participant lesion localization vs. transparency
answer templates
A. Discussions for each case presented will follow and include:
1. Diagnosis
2. Visual field analysis
3. Pertinent ancillary tests utilized
4. Neurologic signs / symptoms and other clinical correlates
5. Pertinent reviews regarding each visual field lesion’s
anatomical pathway and territories
6. Clinical pearl
IX.
Conclusion: Key points and pearls when interpretating visual
field defects:
A. Patient history
B. Patient responses
C. Clinician interpretation
D. Retina fiber pathway
E. Optic nerve anatomy
F. Visual tract & brain anatomy