Transcript the PowerPoint

Vision Impairment from an
Acquired Brain Injury
Presenter:
Xenia Holland, OTR/L
Occupational Therapist
November 6th, 2016
Brain- lobes and functions
Vision as a process
Visual
Pathway
Vision
• Takes us farthest and fastest into the
environment
• Provides speed for decision making- can convey a
lot of info in seconds
• Allows us to anticipate and plan for situations
• Allows us to adapt to dynamic environments
• Helps to elicit and guide movement
• Early warning system- helps us maintain postural
control
Common visual problems in ABI
• Visual acuity deficits
• Oculomotor (eye movement) deficits
• Visual field loss
Leads to:
Difficulty completing vision-dependent activities
Visual acuity deficits associated with
acquired brain injury
• Blurred vision –
corneal scarring, trauma induced cataract,
vitreous hemorrhage
• Focusing difficulties –
“accommodation” changes after stroke
• Damage to retina –
“stroke” of eye, trauma related detachment
Quality of image sent to brain for processing is
damaged to varying degrees
If oculomotor system is working
normally…
• Six pairs of muscles that
attach to the eye ball
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Medial rectus
Lateral rectus
Superior rectus
Inferior rectus
Superior oblique
Inferior oblique
• Work together to move the
eye through the 9 cardinal
points of gaze
• Binocular function
• Innervated by 3 cranial
nerves
– Oculomotor Nerve (CN III)
– Trochlear Nerve (CN IV)
– Abducens Nerve (CN VI)
If not working normally, double vision
can occur
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The Oculomotor (eye movement) system works to
keep the target on the fovea to ensure that it is
clearly seen
Eye movements are under a complex combination of
cortical, brainstem and cerebellar control
All control is exerted via the 3 cranial nerves that
control the extraocular muscles that move the eyes
If system is affected, 2 images may occur leading to
double vision
Oculomotor deficits associated with
acquired brain injuryLesions of cranial nerve 3, 4 or 6
• Complete lesions result in “tropia”- eye turned in/out
• Incomplete lesions result in “phoria”- tendency of eye
to turn in/out
• 3rd and 6th cranial nerve lesions cause lateral double
vision (images split side by side)
• 4th cranial nerve lesion causes vertical double vision
(images split up and down)
• Functional complaints often involve reading, eye hand
coordination and mobility
• Most CN lesions resolve within 6 months of injury
Examples of CN 3 (Oculomotor)Lesion
Client is looking straight ahead
at target; left eye is deviated
outward in exotropic position; pupil is
dilated compared to the right.
Ptosis: drooping eyelid on left side
• Decreased up/down eye
movements
• Horizontal double vision for
near/distance
• Exotropic eye- in outward
position
• Drooping eyelid
• Fixed, dilated pupil*
• Decreased accommodation
• Difficulty near tasks, reading
Example of CN 4 (Trochlear) Lesion
• Impaired down and out eye
movement
• Vertical double vision for
near/distance*
• Hypertropic (elevated) eye
position
• One sided lesion: may observe
a head tilt to opposite side
• Two sided lesion: may observe
downward head tilt
• Most vulnerable cranial nerve
to injury
– Difficulty reading
– Difficulty going
down stairslacking down and
out eye
movement
needed to
monitor support
surface
Unilateral CN 4 Lesion:
Head is tilted slightly towards
shoulder on non involved left
side to avoid diplopia
Head is tilted towards deficit right side
causing right eye to assume
hypertropic position
Bilateral CN 4 Lesion: Assumes a head down
position to avoid diplopia
Example of CN 6 (Abducens)Lesion
• Unable to move eye
outwards
• Esotropia or Esophoria
– Cross-eyed
• Complains of lateral
(side) double vision for
distance
• Limitations in
– Driving
– Ambulation
– Activities completed at
a distance
• Image From
http://www.aapos.org/term
s/conditions/100
The Visual Field
• Area of visual world that
can be seen when
looking straight ahead
• About 180 degrees
horizontally
• About 135 degrees
vertically
• Pathway traverses the
entire length of the brain
from the retina to the
calcarine fissure of the
occipital lobe
• Most deficits results from
damage along this
pathway
Visual field deficits (VFD) associated
with acquired brain injury
• VFD in Adults are due to
– Stroke- infarction (63%)
– TBI (12%)
– Hemorrhage (11%)
Most commonly leads to:
• Hemianopia-homonymous hemianopia,
binasal, bitemporal
• Quadrantanopia- superior, inferior
Visual Field Deficits
* 75% result in homonymous hemianopia
* 70% with complete hemifield impairment
* 30% macular sparing
PCA Lesion
PCA Lesion
Visual field deficits
Effect of Visual Impairment on
functional performance
• 1. Change in speed of information processing
• 2. Change in decision making
• 3. Change in response to the environment.
The changes in these various areas may affect all
aspects of daily living and mobility from
performance of the simplest self-care task to the
ability to resume driving and return to work.
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Functional Implications of visual field
loss
1. Frequently bumps into objects like door-frames or people
2. Difficulty and uneasiness in moving about in crowded areas.
3. Unsure of footing while walking and may trip or stumble.
4. Often startled by moving objects or people appearing suddenly.
5. May have bruises on shoulder or arm from colliding with door-frames.
6. Frequently loses place in reading.
7. Struggles to find or misjudges the start or end of a line of print in
reading.
8. Frequently spills drinks when eating.
9. Unsteady balance in walking and may report dizziness.
10. Problems in finding things on desks, counter tops, cabinets or closets.
11. Fear or anxiety in walking through unfamiliar areas.
12. Uneasiness or even panic attacks in crowded area.
13. Withdrawal from going to stores or other crowded areas.
14. Gets around well at home, but avoids outside activities.
Changes in Behavior
• Anxiousness and uncertainty in
responding to the environment
• Decreased confidence in ability to
complete activities
• Increased passiveness in decision
making
Changes in Orientation
• Insufficient visual input to accurately map space
on involved side
– May result in perceptual completion
– Inability to scan fast enough to comprehend scene as
a whole
• Tendency to get lost
– Very uncomfortable navigating alone
– Avoids independent travel
Changes in Mobility
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Hesitant, uncomfortable, anxious
Stiff, uncertain gait
Shoe gazing
Coming very close to obstacles
Uncertain on subtle features
Stopping to search
Pre-intervention plan
• Check eyeglasses
• Referrals to OD/MD, other disciplines as
needed
• If prisms/occlusion/lenses prescribed, then
know why, when, how to use
• Review any eye reports and medical history
Intervention:
Visual Acuity & Oculomotor
• Modify environment to increase visibility
– Increase contrast
– Optimal illumination
– Reduce pattern
• Reduce demands on vision
– Organize environment and tasks
– Eliminate steps in task that depend on vision
• Create predictable environments
– Maximize organization and structure
Ways to reduce visual demands..
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Take frequent breaks when doing near tasks
Use magnification
Increase contrast
Avoid bothersome light sources
Reduce glare
Avoid visual overload
Use organization tools- “a place for everything
and everything in it’s place”
• Use alternative sources such as audio devices,
screen readers, phone apps etc
Intervention in visual field lossImprove search strategies
• Focus on developing efficient search strategies
to compensate for field deficit
• Work in contextual situations
• Specifically increasing
– Width, efficiency, accuracy of head turn
– Visual anticipation/attention towards side of visual
loss
• Goal is that client automatically employs search
strategies without explicitly thinking about them
– Search strategies become second nature
• Requires over practicing visual skills
Intervention in visual field lossimprove navigation/mobility
Problem
• Does not accurately assess dynamic environment in timely
manner resulting in
• Collisions
• Disorientation
• Dangerous maneuvers
Desired behaviors
– Wider head turn
– Increased head movement indicating increase in
anticipatory behavior
– Organized, efficient search pattern
– Before entering an environment, scan thoroughly to locate
potential hazards
– Increased attention to visual details
Consideration of hemi-neglect and
hemi-inattention
• Hemi-neglect is a perceptual deficit not a visual one
• Person cannot attend to or process the visual information received
• Can be coupled with a hemianopia, the person can not or does not
readily/spontaneously scan into the area of the hemianopia.
• No awareness that a hemi field loss exists
• Says doesn't see out of the eye (on the side of the neglect)
• Bumps into things on side of the hemianopia but doesn't learn to
compensate for the problem
• Misses parts of words on the side of the neglect when reading
• Misses parts of eye chart line on the side of the neglect
• Tendency to orient head or body turned away from the neglect, and
the patient may ambulate/drift in direction away from the neglect.
Hemi-neglect leads to limitations in …
• Locating items
• Completing tasks
• Multi-tasking
• Rapidly and accurately assessing situations
Affecting…
Participation in driving, sports, work and many
activities of daily living
Interventions for:
Hemi-Neglect
• Scanning exercises to side of neglect.
• “Closed eye” throwing movement.
• Encourage awareness of the "feel" of their eyes when gazing
as far toward the neglect as possible.
• Walk in direction toward the neglected side.
• Flashlight aimed at each side while moving around.
• “Real” board games or cards, they engage tactile sense.
• Use a "beeper-timer" wristwatch as reminder to scan
• Facilitate sustained attention- reduce distractions, use familiar
tasks and places
• Select emotionally meaningful activities- increases motivation
• Create attention supporting environments and activities!!!
Take Home Messages
Visual impairments due to ABI:
• can vary from mild to severe and can affect
one or many areas along visual pathway.
• they alter quality and amount of visual input
to brain and alter the way brain uses that
information.
• Increasing knowledge of how and why they
occur can help in developing an intervention.
Intervention Resources
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www.eyecanlearn.com
www.hemianopsia.net
www.positscience.com
www.lumosity.com
www.sharpbrains.com
www.cogmed.com
Slide references
*****Slides 5-20, 20,22,23,24,26,28,29, 30,31 & 33 Received permission from Mary Warren to use the
material/information included in these slides:
Mary Warren PhD, OTR/L, SCLV, FAOTA
Associate Professor, Occupational Therapy
Director, Graduate Certificate in Low Vision Rehabilitation
Co-Director, UAB Center for Low Vision Rehabilitation
University of Alabama at Birmingham
External websites and links:
• http://www.cdc.gov/traumaticbraininjury/pdf/BlueBook_factsheet-a.pdf
• http://braininjurysociety.com/information/acquired-brain-injury/understanding-the-brain/
• http://www.lowvision.org/traumatic_brain_injury.htm
• https://aapos.org/terms/conditions
• https://www.youtube.com/watch?v=hDbWV0EZCAU
• http://www.braininjuries.org/hemianopsia_field_loss.html
• http://www.braininjuries.org/brain_injury_double_vision.html
• http://www.braininjuries.org/traumatic_brain_injury.html
• http://www.hemianopsia.net/symptomschecklist/
Clinical References
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“Introduction to Vision and Brain Injury” by Thomas Politzer, OD. https://nora.cc/for-patientsmainmenu-34/vision-a-brain-injury-mainmenu-64.html
Neuro-Optometric Rehabilitation Association website: www.nora.cc
“Loss of Visual Field due to Brain Injury Hemianopsia and Neglect” by Dr. Errol Rummel,
FAAO, FCOVD, FNORA. http://www.braininjuries.org/hemianopsia_field_loss.html
Spatial Rehabilitation Using Field Enhancement Prism Systems by NORA Webmaster, 2008
https://nora.cc/visual-field-loss-rehabilitation-mainmenu-78/spatial-rehabilitationmainmenu-182.html
Rehabilitation: Bitemporal hemianopsia: https://nora.cc/content/view/125/183/
https://nora.cc/content/view/122/180/
Books:
• Zoltan, Barbara. Vision, Perception and Cognition: A manual for the Evaluation and Treatment
of the Neurologically Impaired Adult. 3rd Edition. Slack Incorporated, New Jersey, 1996
• OphthoBook: An Introduction to the Eye. 2010 Edition.
Special thank you to Mary Warren for her kind
permission to use her information and resources.
Mary Warren PhD, OTR/L, SCLV, FAOTA
Associate Professor, Occupational Therapy
Director, Graduate Certificate in Low Vision Rehabilitation
Co-Director, UAB Center for Low Vision Rehabilitation
University of Alabama at Birmingham