Transcript handout 1 - Association for Education and Rehabilitation of the Blind

Vision Rehabilitation Techniques for TBI
Carl Garbus, O.D., FAAO
Neuro Vision Rehabilitation Institute
Valencia, CA
Learning Objectives
Describe the incidence and prevalence of brain injury
Distinguish between acquired brain injury and
traumatic brain injury
Identify basic brain structures and functions
Describe 2 main visual processes in the brain
Describe visual consequences of brain injury
Discuss assessments and interventions
Goals for the Presentation
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Create awareness of what to look for in patients
who have had traumatic brain injury
Stress the importance of having a neuro vision
evaluation for patients with traumatic brain injury
and stroke
Know that neuro vision rehabilitation exists for
patients with these conditions
Definitions
Traumatic brain injury (TBI)
•
An insult to the brain, not of a degenerative or
congenital nature but caused by an external
physical force,

That may produce a diminished or altered state
of consciousness.

Causes of TBI:
Motor vehicle accidents - whiplash
Falls
Gunshot wounds
Work place injuries
Shaken baby syndrome
Child abuse
Sports injuries
Military actions
Different ways
brain can be
damaged
Neck Trauma
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Whiplash:
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A simple whiplash can cause shearing of nerve
fibers in the brain stem
This can occur from being rear ended by a car
driving moving at 15 miles an hour
Disruption of fibers in the brainstem affects
oculomotor and binocular functions.
Basic brain structures
and functions
Lobes
" The eyes see only what the
mind is ready to comprehend"
Henri Bergson
Brain and vision:
the connection
Every lobe of the brain is involved in processing
visual information.
To date, researchers have identified over 300 intracortical
pathways linking 32 different cortical areas involved in vision
function.
More than half of our gray matter and multiple subcortical
areas are involved in processing vision.
There is more area of the brain dedicated to vision than to all
the other senses combined.
The Visual Brain
Vision is a Bimodal System
There are 2 main pathways that carry visual
information from the eye to the brain.
Focal - the "what" system
Ambient - the "where system"
Designed to simultaneously process
different types of visual information
Neither works in isolation of the other;
both reinforce one another
Focal and Ambient Systems
 Need
to work in harmony
 They
are not isolated systems
A
disconnect in the ambient
system will cause problems
with spatial orientation

Symptoms include: balance problems,
bumping into things, difficulty navigating
Five Pillars of Function
Visual
Physical / Vestibular
Somatosensory
Cognition
Psychosocial
Why is vision rehabilitation so
important following brain injury?
Vision is our dominant sense; we are visual beings.
Vision is pervasive throughout our brain.
Vision is represented all over our body.
Vision influences and influenced by anything and everything - the
way we think, say, or do.
Visual problems are among the most common consequences of
TBI and or CVA but frequently not dealt within rehab model.
Visual Consequences of TBI:
Post Trauma Vision Syndrome (PTVS)
A constellation of symptoms that evolves as secondary injury in
TBI.
This syndrome is caused by a dysfunction of the ambient visual
system and has the characteristics listed below:
Binocular coordination dysfunctions - double vision
Inability to perceive spatial relationships between
objects
Difficulty fixating on object and following when it moves
Abnormal posture
Dizziness and balance problems
Poor visual memory
Visual consequences of TBI:
Post Trauma Vision Syndrome (PTVS)
Poor concentration and visual attention
Difficulty with visually guided movements
(bumping/tripping, knocking things over)
Light sensitivity / photophobia
Visual midline shift syndrome
Visual spatial difficulties
Sense of balance
Bump into things
Difficulty with eating
Slow reading
What are the functional implications?
Binocular Dysfunction
Difficulty judging
distance or depth
Tendency to knock
things over
Bump or trip over
obstacles
Difficulty playing
sports
What are the functional implications?
Visual information processing
Avoidance of
crowded or busy
places
Short memory
Forget familiar route
Slow to process
Visual Midline Shift
Mismatch
between the perceived egocentric
visual midline and the actual physical midline
Causes an expansion on one side
Causes a contraction on the opposite side
Visual Midline Shift Syndrome
Signs and Symptoms
Floor
may appear tilted
Walls
and/or floor may appear to
shift and move
Veering
during mobility
Person
leans away from the
affected side
Feelings
of imbalance or
disorientation similar to vertigo
Cranial Nerve VIII –
Auditory and Vestibular Nerve

Nerve that
transmits
information for
hearing and
balance
Vestibular Function
The
visual system links up very closely with the
vestibular system in the brainstem and midbrain
–Ocular Reflex (VOR) is activated
when there is a head movement, body
movements or if the individual leans to one side
Vestibular
Vestibulo-Ocular Reflex
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Maintenance of fixation of the eyes with
head movements
It is activated with horizontal and vertical
head movements
This intricate system links the vestibular
system to the oculomotor system
Interventions
Patient education
Explain brain and vision relationship
Review individual's specific diagnosed eye
condition in plain language
Why and how vision may be interfering or
limiting daily functions.
Always include family members whenever
possible
Interventions
Strategies
Relieve visual discomfort from eye strain and
fatigue often leading to headaches.
Take care of those dry eyes!
Reduce glare and light sensitivity - very
important!
Take frequent breaks from visually demanding
tasks - 20/20/20 rule
Interventions
Limit use of computer and mobile devices
Recognize and avoid non visually- friendly
reading materials
Use color filter overlays to reduce strobbing
effect of black on white paper
Utilize adaptive tools to assist with visual
stamina (magnifiers, Kindle, long cane)
Glasses need to be up to date
Lens is designed for the task
Interventions
Therapy
Safety first! O&M training to
improve viewing posture,
balance, and stability, spatial
awareness and relationships
for interaction with
environment with better
accuracy. Long white cane
training if field loss.
Strategies for Double Vision Techniques
 Consult with an optometrist or ophthalmologist who
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has experience with brain injury
Provide a translucent patch (not dark opaque patch)
Spot patch
Sector patch
Binasals
Active therapy prescribed by the eye care
practitioner can improve binocular function- Eye
Stretches, Tactile Control, Spatial Localization, Brock
String
Interventions
 Prisms: bends light towards the base, which causes
the image to move in the opposite direction---- has
implications to change spatial orientation and eye
alignment
 Lenses: optical correction of refractive conditions
helps to locate objects in space and helps with visual
comfort
 Filters: blocks specific light frequencies that cause
visual discomfort which can improve visual
performance
Strategies for Light Sensitivity
 Turn off or avoid fluorescent lighting
 Increase exposure to natural lighting
 Wear prescription sunglasses with Polaroid lenses
 Consider side shields
 Wrap around frames
Strategies for Light Sensitivity
 Blue-tec lens filter (indoor)
 Green-blue filter for use in areas where fluorescent
lighting is unavoidable
 Binasal occlusion
 Light therapy program
Strategies for Disorientation and
Dizziness
 Grounding techniques
 Thumb and forefinger stimulation
 Proprioceptive input
 Breathing technique
Strategies for Improving Mobility
 Special prescription glasses specially designed to
enhance mobility
 Consult with an optometrist/ophthalmologist who has
experience with brain injury and vision rehabilitation
 Yoked prism lenses maybe useful in therapy or as a
full time prescription
 Binasals can provide grounding and reduce visual
confusion
 Referral source is NORA
Yoked Prism Glasses
 Special prism lenses prescribed by a rehabilitation
eye doctor
 Prisms bend light in a specific direction towards the
base of the prism
 Prisms can alter the patients visual spatial
orientation and posture
 Navigation can be improved over uneven or
challenging surfaces
Yoked Prism Glasses
 Demonstration
 The Effect of Prisms for Mobility and
Navigation
Strategies for Improving Mobility
 During mobility training observe posture, arm swing,
body alignment, balance, head position and turns
 Observe visual balance
 When balance is a problem use the technique of
eyes leading the way before making turns
 Obstacle Course procedures
Obstacle Course
 Place 3 chairs approximately 3 feet apart
 The patient is shown how to navigate around the
chairs
 Changing visual conditions for navigation
 Adding visual stimulus to the sides
 Adding auditory stimulus
 Demonstration
Strategies for Visual Field Loss
 Identify where the losses are located with visual field
 Does it affect ambulation?
 Does it affect reading?
 -------------------------------------------------------------- Trial Peli Prisms for hemianopsia
 Trial yoked prisms
 Improve scanning skills
 Need single vision Rx glasses (distance and near)
 Progressives limit peripheral visual field function
Strategies to Enhance Visual
and Vestibular Integration
Specific Procedures
 Head Rotations With Central Fixation
 Chair Rotations
 Body Rotations
 Four Corner HART Charts
 Side To Side HART Chart Rotations
 GOALS: better coordination of these systems can
be accomplished by using vision to support
vestibular
Summary
 Consult with an vision rehabilitation
doctor to collaborate about
functional treatments
 Consider visual conditions that can
be treated such as light sensitivity,
visual balance, visual midline shift
and post trauma vision syndrome
 Brainstem damage will have visual
and vestibular consequences
 Double vision is common problem
that needs to be dealt with early
Summary
 Good referral source is the Neuro
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Optometric Rehabilitation
Association
Avoid crowded environments
Inquire about yoked prisms and
binasal occlusion
Use the grounding techniques
described in this course
Don’t give up there are many
solutions to improve the quality of
life after a traumatic brain injury
Neuro Optometric
Rehabilitation Conference
 24th Annual Multi-disciplinary Conference
 Renaissance Hotel
 May 14-17, 2015
 Denver, CO
 Website www.nora.cc
 Email: [email protected]