Download Visual Consequences following a Concussion

Dr. Jennifer Kungle
Neuro-Optometrist
The Center for Vision Development
Coup Contra-Coup Injury
The Visual Pathway
Key Visual Signs/Symptoms
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Headache
Blurry vision
Photophobia
Double vision
Reading problems
Decreased processing speed
Dizziness/motion sickness
Peripheral vision defects
 Nearly 30% of concussed athletes report visual problems
during the first week after the injury
Baseline Testing
1. Cognitive Baselines
Standardized Assessment of Concussion (SAC)
ImPACT Testing
Sports Concussion Assessment Tool, SCAT-2
2. Balance Baseline
Computerized
Timed Tandem Gate Test
3. Visual Baseline/Remove from Play
King Devick Saccadic Test
VOMS
RightEye Neuro Vision
ImPACT
 Immediate Post-Concussion Assessment and Cognitive
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Testing, developed by UPMC
Neuro-cognitive test that evaluates multiple aspects of
memory, attention, brain processing speed, reaction
time, and post-concussion symptoms.
Designed for children above 8 years of age.
Baselines should be repeated every two years for >13 yo
Baselines mandated by NFL, NHL and many collegiate
and high school teams.
 Impacttest.com to find providers
King Devick Saccadic Test
King Devick Saccadic Test
 The K-D Test has been widely used through the years
as a measure of saccade function primarily as related
to reading.
 Measures rapid eye movement, visual tracking and
related cognitive responses; is a reliable indicator of
cognitive problems.
 If an injured athlete reads the numbers more slowly
after a head impact as compared to baseline testing,
he or she is considered to have sustained a
concussion.
September 10, 2015, in Concussion
 1419 athletes; 86% specificity detecting
concussion
 King-Devick times 4.8 seconds slower for
concussed athletes vs. 1.9 seconds faster for nonconcussed
 Physical exertion sharpens visual processing,
often causing non-concussed athletes to
perform better than their baseline
Critique: does not evaluate other areas of ocular motor function
such as pursuits, convergence, or accommodation
Vestibular Ocular Motor Screening
VOMS – developed at UPMC
Assessments in the following five domains:
1) smooth pursuits
2) horizontal and vertical saccades
3) convergence
4) horizontal and vertical vestibular ocular reflex (VOR)
5) visual motion sensitivity (VMS)
Following each VOMS assessment, patients rate on a scale of 0 (none)
to 10 (severe) symptoms of: headache, dizziness, nausea and fogginess
Takes 5-10 mins to administer.
Eye Tracking Technology
 Circular smooth pursuit
 Horizontal smooth pursuit
 Vertical smooth pursuit
 Horizontal volitional saccades
 Vertical volitional saccades
 Sample_Neuro_Report_Feb_2017.pdf
The Duality of the Visual System
Focal Vision System
What/How Pathway
Ambient Vision System
Where Pathway
 Concentration
 “Peripheral Vision System”
 Localizes our bodies in space
 Balance, Movement,
Coordination, Posture
 Gravity-Specific
 Detail-oriented
 Pre-Conscious
 High-resolution, central
vision = identification of
objects
 Attention
 Conscious
 Anticipatory
 Reactive
 Stimulated by motion
Ambient Processing
In the midbrain visual inputs combine and organize
sensory information with information from
 Vestibular (VIII)
 Proprioceptive
 Tactile
 Kinesthetic
After acquiring additional sensory input, nerves travel
in a feed-forward mechanistic process to the visual
cortex.
Sensorimotor Connection
All sensory systems are integrated neurologically.
While initially separate, they all join together to
integrate sensorimotor information in the brain.
 Some patients note that when they take off their
glasses they have difficulty hearing
 Not only sensory system share information – also
the motor process (efferent pathway) is critical in
providing a background for the sensory system.
ex. Balancing on one foot – much more difficult
when eyes are closed.
Ambient Processing
The ambient system is responsible for grounding our
spatial world through sensorimotor matching.
When this system is damaged by injury, grounding is
affected and there is a shift towards focalization.
= Focal Binding
This causes the person to project movement onto stationary
objects which are fixated, and they perceive objects to be
moving.
i.e. print on the page may appear to move
Ambient Processing
When in busy, visually stimulating environments, this
over focalization and isolation on detail will be
overstimulating – causing confusion and spatial
distortion.
What happens with TBI?
 In a neurological event such as a TBI, MS, cerebral palsy,
autism, CVA, etc., the balance between the ambient and
focal visual processes is often affected.
 M-cells have larger diameter axons and are more
susceptible to damage. Damage can come from
ischemia, space occupying lesions, etc.
 mTBI – concussion – diffuse shearing of axons leads to
release of neurotoxins – creates hyper excitability –
throws off the ambient system
AMBIENT PROCESSING BECOMES DECOUPLED FROM
FOCAL PROCESSING = focal binding
unable to process peripheral information
 Exophoria/exotropia
 Diplopia
 Reduced depth perception/localization
 Unable to match visual to proprioceptive, kinesthetic,
vestibular information
 Balance, coordination and movement are compromised
 Are unable to suppress second image
Post Traumatic Vision Syndrome
Characteristics:
1. Exotropia/High Exophoria
2. Convergence Insufficiency
3. Accommodative Deficiencies
4. Visual Spatial Distortions
5. Oculomotor Deficits
Unstable AMBIENT system
Post Traumatic Vision Syndrome
Symptoms
1. Diplopia, possible
2. Objects appear to move
3. Reduced concentration and attention
4. Poor visual memory
5. Glare sensitivity (photophobia)
6. Problems with
 Balance
 Coordination
 Posture
Vision Rehabilitative Therapy
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Binocular Integration
Oculomotor control, speed, accuracy
Accommodative flexibility, stamina and endurance
Smooth and easy convergence/divergence
Peripheral Awareness
Visual Motor Coordination
Visual Perceptual Spatial Knowledge
Multi-Matrix Game
Neuro-Optometric Treatment Options
1. Lenses
 Avoid Multifocals
 Always consider two pairs of glasses
 May require additional computer Rx or sun
Rx
 Polarized/Transition Lenses
 Tints
Neuro-Optometric Treatment Options
2. Compensatory Prisms
 Fresnel Press-On Prisms (temporary)
 Can be ground into standard lenses
Fresnel Prism
3. Therapeutic Prism
 Base In yoked prism helpful
in decreasing visual stress;
aids divergence; decreases
photophobia and eyestrain
 Yoked prism can be used
to realign a patient’s center
of gravity and improve
overall balance
4. Patches
 Cling Patches (Bangerter Occlusion Foils)
can vary from opaque (light perception) to
varying degrees of translucency
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Provide varying acuities, i.e. 20/50, 20/200,
light perception
Occlusion Options
 Partial or spot patches can be used as immediate
treatment for double vision.
 Partial patches will allow the patient to maintain
peripheral awareness and facilitates their overall
coordination and balance.
 Occlusion Therapy without an assessment is NOT
recommended.
Superior Occlusion
Spot Occlusion
Binasal Occluders
THANK YOU!
marylandvisiontherapy.com
[email protected]
Nora.cc
COVD.org
Oepf.org
Neuro-Optometric Rehabilitation Association
College of Optometrists in Vision Development
Optometric Education Foundation
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