Transcript CVI - OIT News and Announcements | SFASU

CVI
Cortical
Visual
Impairment
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The current leading cause of visual
impairment among children is not a
disease or condition of the eyes, but
cortical visual impairment (CVI)—also
known as cerebral visual impairment—in
which visual dysfunction is caused by
damage or injury to the brain.
Medical definition
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Cortical visual impairment (CVI) may be
defined as bilaterally diminished visual
acuity caused by damage to the
occipital lobes and or to the
geniculostriate visual pathway.
CVI is almost invariably associated
with an inefficient, disturbed visual
sense because of the widespread brain
damage.
Educational definition
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Cortical visual impairment (CVI) is a
neurological disorder, which results in
unique visual responses to people,
educational materials, and to the
environment.
When students with these
visual/behavioral characteristics are
shown to have loss of acuity or judged
by their performance to be visually
impaired, they are considered to have
CVI.
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During the last several decades, our
understanding of vision has markedly
improved. It is now realized that vision
is not a single sense but a combination
of complex senses, involving most of
the brain in its process.
In different locations of the brain,
there are specialized areas for
distance vision, recognition of faces,
objects, colors, contrast, and
movement.
Cause
 CVI
is caused by
widespread damage to the
brain, which affects most of
the specialized visual
centers, resulting in a
damaged, inefficient visual
sense.
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The medical definition of CVI is not well
understood by non-medical professionals.
While acuity testing is difficult in the young
and disabled for physicians, it is even more
difficult for teachers.
Also, there are many children with visual
problems similar to CVI, except they have
normal acuity.
This visual condition is called "cortical visual
dysfunction" (CVD).
The educational management of children
with CVI and CVD is similar.
CVI is suspected by:
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a normal or close to normal eye
examination;
a medical history which includes
neurological problems; and
the presence of unique
visual/behavioral characteristics.
Unique visual/behavioral
characteristics
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Normal or minimally abnormal eye exam.
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Difficulty with visual novelty.
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Prefers to look at old objects, not new, and lacks
visual curiosity.
Visually attends in near space only.
Difficulty with visual complexity/crowding.
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CVI may co-exist with optic nerve atrophy, hypoplasia
or dysplasia and ROP.
Performs best when one sensory input is presented
at a time, when the surrounding environment lacks
clutter, and the object being presented is simple.
Non-purposeful gaze and/or light gazing behaviors.
Distinct color preference.
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Preferences are predominantly red and yellow, but
could be any color.
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Visual field deficits.
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Visual latency.
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Visual responses are slow; often delayed.
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Fails to blink at threatening motions.
Attraction to movement, especially rapid
movement.
Absent or atypical visual reflexive responses.
Atypical visual motor behaviors.
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Not so much the severity of the field loss, but
where the field loss is located.
Look and touch occur as separate functions, e.g.,
child looks, turns head away from item, then
reaches for it.
Inefficient, highly variable vision.
Strategies
1. Slow down.
2.Allow time for student to
respond.
3.Simplify the task.
4.Schedule visual experiences for
the time of day when the
student demonstrates optimal
visual functioning.
5. Be specific about what you want the
student to see and to do.
6. Sequence the task.
7. Provide structure and sameness in
each presentation.
Environment
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Provide an environment that is free
from visual clutter.
Be sure that the work surface does
not have a pattern.
Be sure that the learning environment
has only essential visual information,
especially on background surfaces and
spaces.
Materials
1.
Enhance the visual targets.
2.
Keep visual information simple,
constant, and predictable.
3.
Use real objects in natural sequences
to aid in the understanding of the
real visual environment.
To summarize:
CORTICAL VISUAL IMPAIRMENT
Cortical Visual Impairment (CVI) is a temporary
or permanent visual impairment caused by the
disturbance of the posterior visual pathways
and/or the occipital lobes of the brain. The
degree of vision impairment can range from
severe visual impairment to total blindness. The
degree of neurological damage and visual
impairment depends upon the time of onset, as
well as the location and intensity of the insult. It
is a condition that indicates that the visual
systems of the brain do not consistently
understand or interpret what the eyes see. The
presence of CVI is not an indicator of the child's
cognitive ability.
What all should be in a CVI/Functional Vision Evaluation Kit?
 September 1, 2008 — Created by Diane Sheline, CTVI, CLVT,
[email protected]
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updated 09/18/2008
CVI FUNCTIONAL VISION EVALUATION KIT
• Penlight/flashlight with different colored caps/filters
• Flashlight with different colored filters
• Mylar Pompoms…preferably red and yellow
• Cereal and other real or simulated food items…Fruit Loops, red licorice,
banana, Cake Decors and Cheerios
• Mylar paper or wrapping paper…preferably red and yellow
• Soap bubbles, for blowing
• Measuring tape
• Slinky…solid colors and plastic
• Hidden pictures or I Spy book
• Variety of different colored balls in a variety of sizes
• A black, light-absorbing background…2 yards of black fabric,
Invisiboard, or other similar material/board
• 2 yards of white fabric
• Variety of flashing lights…including bikers safety light, snap-on-spoke
light clips, etc.
• Supplementary light…such as a clamp on directional light
• Variety of yellow and red toys… such as Elmo, Big Bird, reflective
mirror, balls, etc., or “sets of red and/or yellow objects to be sorted
into same colored containers
• Black and white toys
• Mirrors
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MORE MATERIALS:
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Reflective materials – mylar balloons, pom poms, shakers, etc.
Suspended or moving objects (windsock, ball on elastic cord, etc.
Slap bracelets in reflective red and yellow
Blinking “ice cubes” attached to elastic “ring” band…or any blinking lights that can be
thoroughly cleaned/washed
Personal “Laser Light Show” fan
Spinning Pinwheel on long stick (yellow or red
Variety of sunglasses…BabyBanz, yellow clip-ons, overglasses sunglasses, etc.
Croakies…adjustable straps to hold glasses in place
Visors or brimmed caps
Items from everyday routines in solid colors…cups, spoons, toothbrushes, etc.
Container of Lysol wipes
Notebook of variety of CVI articles for parents
Rolling suitcase to hold it all in
Extension cord(s)
Extra Batteries (AA and AAA)
Selected equipment and materials from APH including;
o Regular or Mini Light Box with clear and colored overlays and colored acrylic objects
o ToAD: Tools for Assessment and Development of Visual Skills
o Invisiboard
o ISAVE Visual Field/Acuity Grid
o Sensory Learning Kit
Make sure to have the parent bring in the child’s favorite toy
Created by Diane Sheline, CTVI, CLVT, [email protected] updated 09/18/2008
 What
will cause the use of
the vision?
“rut” in the snow
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http://www.aph.org/cvi/advo.html
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http://www.aph.org/cvi/index.html
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http://dianesheline.wordpress.com/toolb
ox/techniques-and-strategies-to-usewith-students-with-cortical-visualimpairment/