Transcript Cortical Visual Impairment and the Evaluation of

CVI Symposium
Ellen Cadigan Mazel M.Ed., CTVI
Perkins School for the Blind
May 2015
Today’s Goals
• Discuss CVI
• Discuss the evaluation of CVI
• Discuss theories and assessment: Dr. Roman
Lantzy and Dr. Gordon Dutton
Today’s Goals
CVI assessment and strategies for older
students.
• Considerations with increased age?
• Improvements expectations with increased
age?
CVI: All in the Brain
• Damage to the visual cortex
• Damage to the visual pathways
• Both
CVI
• Child can not process or understand
visual information.
• Cortical visual impairment is the leading
cause of visual impairment in children.
Rethinking
• Consider assessment and strategies
for ocular impairment to be
inappropriate for dealing with a
child with cortical visual
impairment.
Dorsal Stream
Where is the target?
• Tells us about the object’s
orientation in space.
• Responsible for eye hand
coordination.
• Give us perception of movement.
Ventral Stream
What is the target?
Recognizes:
• Faces and facial expressions
• Colors
• Shapes
• Writing
• Objects
Statement on CVI
August 2008
• APH advisory group: provide guidance to
develop products for CVI.
• Dr. Christine Roman-Lantzy and Dr. Gordon N.
Dutton and 9 others.
Agreement
• Definition: Brain based visual impairment of
visual cortex and/or visual pathways.
• All children with CVI should be considered
visually impaired.
Agreement
• All children regardless of severity of CVI
or severity of multiple disabilities
deserve vision services.
Criteria for CVI
• Eye exam does not explain the level of
functional vision.
• There is a history of neurological problems.
• There are distinct behavioral characteristics
for people with CVI.
Low Vision and Legal Blindness
CVI defined:
• Visual acuity: traditional acuity measures
don’t work for CVI
• Visual fields
• Visual abilities compared to peers
Agreement
• CVI functioning ranges from severe to mild.
• Screen for ocular problems.
• Screen for CVI: FVA must be grounded in the
characteristics.
Agreement: Characteristics
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Lightgazing
Poor visual attention
Color preference
Restricted fields
Difficulties with visual complexity
Difficulties with distance
Better visual skills with known objects
Agreement: Characteristics
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Attention to moving objects
Looking away when reaching
Visual latency
Atypical blink reflex
Looking does not mean understanding.
Nearly all children improve but rarely lose the
CVI diagnosis.
Disagreement
Cortical Visual Impairment
vs.
Cerebral Visual Impairment.
Roman: Cortical Visual Impairment
• CVI and the Evaluation of
Functional Vision
• Definition and Causes
• Developed an Assessment: CVI
Range
Roman: Cortical Visual Impairment
• Strategies and environmental supports
• Discusses dorsal and ventral stream: building
from dorsal to ventral.
Ten Characteristics
1. Color
2. Movement
3. Latency
4. Visual Field
5. Complexity
6. Light Gazing
7. Distance
8. Visual Reflexive Response
9. Visual Novelty
10. Visual Motor
Ten Characteristics of CVI
1. Color: Does the child attend to certain
colors?
2. Movement: Does the child attend to moving
materials?
3. Latency: Does the child need a long time to
look?
4. Visual Field: Does the child see in one visual
field better than in other visual fields?
Ten Characteristics
5. Complexity:
• Visual Complexity
• Auditory Complexity
• Positional Complexity
Ten Characteristics
6. Light Gazing/Non-purposeful Gaze: Does the
child always look towards light/seem not to
look?
7. Distance: At what distance does the child
see?
8. Visual Reflexive Response: Does the child
blink to touch and visual threat?
Ten Characteristics
9. Visual Novelty: Does the child like familiar
things and seem to ignore new things?
10.Visual Motor: Does the child reach? Do they
reach while looking? Do they play while
looking?
Characteristics on the CVI Range
Assessment
• Remember each characteristic is on a
continuum.
0 1 2 3 4 5 6 7 8 9 10
• When a child improves with one
characteristic, you expect to see
improvement in other characteristics.
Levels of Severity: Phases of CVI
Phase I: 0-3 on CVI Range
Phase II: 3-7 on the CVI Range
Phase III: 7-10 on the CVI Range
Goals in each Phase
• Phase I: Looking
• Phase II: Vision plus function
• Phase III: Resolving characteristics
Phase I
Case Study
Phase II
Case Study
Phase III
Case Study
Fluctuating Vision
What is “fluctuating vision”?
• Consider the environment.
• Consider the child.
Expecting Improvement
Planning Using Assessment Results
• Base goals on the CVI Phases.
• Create learning supports around Characteristics.
• Create strategies and adaptations matched
functional vision.
• Environmental changes support child’s needs.
• There is no “Therapy”
• You want an approach throughout the day.
• You want strategies to support and build
vision use. (after assessment).
Dutton: Cerebral Visual
Impairment
• Definition and Causes
• Strategies for current functioning
• Discusses dorsal and ventral
streams.
Dutton
• No mention of strategies for
improvement.
• Created Dutton Survey
Dutton Survey
52 questions
• No mention of Color, Movement, Latency,
Light Gazing, Visual Reflexes characteristics.
• Most concerned with visual field (8) and
complexity (33).
CVI Across the Ages
Consider Brain Science
• Plasticity
• Critical periods
Potential for resolution with increasing age?
Brain Plasticity
• Using the brain is important: early and often.
• The brain is most plastic in infancy but studies
show some plasticity continues into adulthood
and old age.
• The most plasticity is in the younger years
Critical Periods
• There may be critical periods for certain types
of learning.
The Mystery of the Brain
• Assess all students regardless of age.
• Place learning supports and envronmental in
place.
• Expect improvement.
Ten Characteristics
1. Color
2. Movement
3. Latency
4. Visual Field
5. Complexity
6. Light Gazing
7. Distance
8. Visual Reflexive Response
9. Visual Novelty
10. Visual Motor
Allie: 19 Years Old
Resources Brain Development
• What’s Going on in There?
• The Brain That Changes Itself
All kinds of kids
Ocular Impairment with CVI
• Any child can have both types of
visual impairment.
• Be aware of both
• Assess for both
• Create strategies for both
What Can You Do?
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Learn and share
TVIs: Understands the assessment
Get an assessment of visual skills: CVI Range
Create strategies and environments
Expect improvements
Assess continually to measure improvements
Change strategies based on the new
assessment.
To Read More:
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Christine Roman-Lantzy,Ph.D.
Jim Jan, M.D.
Gordon Dutton, M.D.
Lea Hyvarinen, M.D.
Mary Morse, Ph.D
Resources
• Cortical Visual Impairment: An Approach to
Assessment and Intervention by Christine
Roman-Lantzy
• CVI Perspectives available on quota from APH
• Dutton CVI Survey
Resources
• American Printing House website:
CVI
• Texas School for the Blind website
• Perkins Webcasts: Teaching
Resources
• cviteacher.wordpress.com
Resources
• The American Foundation for the Blind:
eLearning Center: CVI Focus Webinar 5 sessions
$179
http://www.afb.org/store/Pages/ShoppingCart/Pro
ductDetails.aspx?ProductId=eCVIfocusSERIES&rulin
g=No
• CVI: UMASS Boston Vision Studies Program:
3 graduate credits. Online
CVI Resources
• West Virginia Department of Education:
Cortical Visual Impairment
http://wvde.state.wv.us/osp/vi/cvi/
CVI Symposium
The End
Ellen Cadigan Mazel M.Ed., CTVI
Perkins School for the Blind
May 2015
Typical Visual Development
• Vision develops in an organized developmental way
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Attention then understanding
Lights then objects then people
Fixation then shifting then tracking
Near then far
Peripheral then central
Familiar then unfamiliar
Parts then whole
Simple then complex
Large then small