Download Cortical Visual Impairment

Characteristics of
CVI
Function of vision

No one place in brain is responsible

Organized in different places of the brain
FUNCTIONAL USE OF VISION: Using
vision to complete an activity within
daily life

Not based on
visual acuity

Based on visual,
individual and
environmental
characteristics.
What is CVI?

CVI is a condition in which the eye works but
the part of the brain which interprets the
signals provided by the eye does not. This
will cause the child to have difficulty using
visual input he/she is receiving.

CVI is not an indication of the child’s
cognitive ability.
Differences between Ocular
and Cortical Visual Impairment
CVI: child may see accurate visual image, but
can’t interpret it accurately
 Ocular: child has difficulty obtaining good
visual image, but can process and interpret
image accurately when enough information is
present
 Some children have both

(Levack, 1991)
Let’s talk about CVI

Child has difficulty using visual input
he/she is receiving.

CVI gets better or it gets worse. It can
seem to vary from day to day.

CVI is suspected when:
Normal eye exam
Brain injury
Unique characteristics present
Presence of the unique CVI
characteristics
Characteristics of CVI
Early Resolution
 Light Gazing
 Visual Reflex Response
(touch)
Mid Resolution
 Color
 Latency
 Visual Novelty
 Visual Reflex Response
(threat)
 Movement
Later Resolution
 Visual Field Preference
 Visual Motor
 Complexity




Target
Array
Complexity
Distance Viewing
Light Gazing




Staring at lights or light
sources is often observed;
may also be attentive to
ceiling fans.
May be difficult to redirect
child’s attention away from
a light source.
Sources of light should be
positioned behind child.
When lighted toys or
objects are used the light
should be used to
accentuate or highlight the
item. Toys which have
light and music should not
be used with children in
this phase.
“Light Gazing/Non Purposeful
Gaze” Across Ranges
Range
1-2
May localize
briefly but no
prolonged
fixations on
objects or
faces.
Overly
attentive to
lights or
possibly
ceiling fans
Range
3-4
Range
5-6
Less
attracted
to lights –
can be
redirected
to other
targets
Light is
no longer
a
distractor
Range
7-8
Range
9-10
Color:



Items typically need to be a single color.
May need to use child’s preferred or favorite color.
Once child is looking at a variety of single color items may
need to use favorite, or preferred color, to initiate looking
when child is tired or engaged in activities which may
challenge other areas (i.e.: motor) at the same time.
“Color” Across Ranges
Range
1-2
Objects
viewed
are
generally
single
color
Range
3-4
Has a
“favorite”
color
Range
5-6
Range
7-8
Objects
More
may have colors,
2-3 colors familiar
patterns
regarded
Range
9-10
No color or
pattern
preference
Latency




In Phase I it may take the child extended
periods of time to demonstrate a visual
response.
Child may demonstrate a delay in using vision
to “look at” a target most of the time when a
new item is presented or a new activity starts.
Allow the child multiple opportunities and
extended periods of time to demonstrate a
visual response.
Latency may decrease as the child uses
his/her vision more.
“Latency” Across Ranges
Range
1-2
Range
3-4
Range
5-6
Prolonged
periods of
visual
latency
Latency
slightly
decreases
after
periods of
consistent
viewing
Latency
present
only when
student is
tired,
stressed,
or over
stimulated
Range
7-8
Range
9-10
Latency Latency
rarely
resolved
present
VISUAL NOVELTY



Children prefer familiar
items over novel items.
May ignore something
that is novel.
Very different from ocular
impairments, in which
something new will attract
attention.
“Visual Novelty” Across
Ranges
Range
1-2
Only
favorite or
known
objects
solicit
visual
attention
Range
3-4
May
tolerate
novel
objects if
they share
characteris
tics of
familiar
ones
Range
5-6
Use of
“known”
objects to
initiate
looking
sequence
Range
7-8
Selection
of objects
less
restricted,
requires 12 sessions
of “warm
up” time
Range
9-10
Selection of
objects not
restricted
Visual Reflexive Responses


Visual Reflexive
Response
Response to Visual
Threat
Visual Reflexive Responses
Range
1-2
Range
3-4
No blink in
response
to touch
and/or
visual
threat
Blinks in
response
to touch
but
response
may be
latent
Range
5-6
Blink
response to
touch
consistently
present.
Visual threat
response
intermittently
present
Range
7-8
Visual
threat
response
consistently
present
(both near
90%
resolved)
Range
9-10
Visual
reflexes
always
present,
resolved
MOVEMENT

Objects viewed
have movement
or reflective
property

Way to jumpstart visual
system
Movement
Movement may be needed to initiate
and sustain visual attention,
regardless of how brief.
 Objects which provide the appearance
of movement can be used to initiate or
sustain “looking” (i.e.: toys which
have shiny or reflective properties
such as mylar).

“Movement” Across Ranges
Range
1-2
Range
3-4
Range
5-6
Range
7-8
Range
9-10
Objects
viewed
generally
have
movement or
reflective
properties
More
consistent
localization,
brief
fixations on
movement &
reflective
materials
Movement
continues
to be an
important
factor to
initiate
visual
attention
Moveme
nt not
required
for
attention
at near
Typical
responses
to moving
targets
Visual Fields Preference
Child generally shows a field
dependency or preference.
They have a place where there
“best use of vision” is noted.
 Child will typically use
peripheral vision. May briefly
try to use his/her central vision.
 Child often appears to be
“looking through” people or
objects.

“Visual Fields” Across
Ranges
Range
1-2
Range
3-4
Range
5-6
Distinct field Shows
Field
dependency visual field preferences
preference decreasing
with familiar
inputs
Range
7-8
Range
9-10
Visual fields
May
alternate unrestricted
use of
right and
left visual
fields
Visual Motor
Visual targets need to be simple, noncomplex, because it is probably too
difficult at this point to use his/her
vision and demonstrate a motor
response (i.e.: reaching) in Phase I of
resolution.
 In Phase I child typically does not use
a visually guided reach.

“Visual Motor” Across
Ranges
Range
1-2
Range
3-4
Range
5-6
Look &
touch
occur as
separate
functions.
Large
and/or
moving
targets
Look &
touch on
smaller
objects
that are
familiar,
lighted,
or
reflective
Visually
guided
reach
with
familiar
objects
or
“favorite”
color
Range
7-8
Range
9-10
Look and Look and
touch
touch
occur in
consistently
rapid
sequence
but not
always
together
Complexity



Remember that visual complexity not only
includes what the child is looking at (visual
clutter), but any form of sensory input which
is occurring.
In phase I items need to be presented
against a solid black background.
When working on a child’s vision in phase I
the child needs a quiet environment to work
and play in.
COMPLEXITY

Complexity of
target/object

Complexity of array

Complexity of
sensory
environment
Complexity of Target/Object
Complexity of Array
Complexity of Sensory
Environment
“My Mother in Three Rivers
Stadium” (Chris Roman)
“Complexity” Across Ranges
Range
1-2
Responds only in strictly controlled
environments.
Range
3-4
Visually fixates when environment is controlled.
Range
5-6
Student tolerates low levels of familiar
background noise.
Regards familiar faces when voice does not
compete.
“Complexity” (cont.)
Range
7-8
Competing auditory stimuli tolerated during
periods of viewing - student may now maintain
visual attention on music toys.
Views simple books/symbols.
Smiles at/regards familiar and new faces.
Range
9-10
Only the most complex visual environments
affect visual response.
Views books or other 2-dimensional materials.
Typical visual-social responses.
DISTANCE VIEWING



Often problematic for
children in early phases
In Phase I child typically
only responds within 1824 inches of his/her
face.
May be result of
increased complexity of
visual array
“Distance Viewing” Across
Ranges
Range
1-2
Range
3-4
Visually
attends in
near space
only
Occasional
visual
attention on
familiar,
moving or
large
targets at 23 feet
Range
5-6
Visual
attention
extends
beyond
near
space, up
to 4-6 feet
Range
7-8
Visual
attention
extends to
10 feet with
targets that
produce
movement
Range
9-10
Visual
attention
extends
beyond 20
feet
Demonstrates
memory of
visual
events
Progression of Resolution

Early Resolution
Light gazing, blink reflex

Mid Resolution
color, latency, novelty, visual threat, movement

Later Resolution
Field, visual motor, complexity, distance
viewing
Assessment Framework
 Interview
 Observation
 Direct
Evaluation/Interaction
with Child
CVI Range
CVI can be severe, moderate, or mild
 Phases (I, II & III) describe broad
functioning levels
 Number ranges (0-10 scale used in
assessment) describe specific levels
of functioning
 Phases guide intervention strategy to
support best visual functioning

Ranges
0
to 10 scale
0 = no functional vision
10 = typical visual functioning
 Correlation with phases is approximate
Phase 1
0 to 3.5 score
Phase 2
3.5 to 7.5 score
Phase 3
7.5 to 10 score
Interventions
“Environmental engineering”
 Based on individual child/student
characteristics
 Support the best vision where the child is
functioning NOW
 Learning to use vision
 Remove, decrease supports to environment
as progresses through to “resolution” of CVI
characteristics

Phases

Phase 1 : building stable visual function

Phase 2: integrating vision with function

Phase 3: resolution of CVI characteristics
Phase I
Students generally require:

1.
2.
3.
4.
5.
Single color objects
Objects of preferred color
Objects that produce movement or
are shiny
Objects presented against a simple
background
Objects that are familiar
-Roman-Lantzy,
Phase 2

Students generally require:
1. Reduction of information when presented in 2
dimension
 Use occluders or window cards to eliminate
excess detail
 Highlight or outline critical features of symbols or
pictures
**Students should be at least a ‘7’ on the CVI Range
before asking them to discriminate 2-D objects**
-Roman-Lantzy, 2005
Phase 3
Students generally require:
 For complexity visual field considerations in highly
novel and/or over-stimulating environments
-Orientation (verbal & physical) to the setting
-Assistance from an adult or peer
-Possible use of a cane
 In the classroom help the student think about their
thinking
 Focus on problem solving rather than specific
strategies
-Roman-Lantzy, 2005
CVI in Infancy
First three years are most critical for
permanent changes
 Early identification provides best opportunity
to take advantage of brain plasticity
 Don’t wait for medical diagnosis!
 Parents are best reporters about their
children
 Expect improvements

Impact of Sensory Loss
on Child Development
Always remember to watch for
signs of stress and fatigue!!
Facial grimaces
 Hand and/or finger extension,
opening, and tension
 Light gazing and avoiding looking at
anything
 Yawning and/or “falling asleep”
 Hiccupping
 High pitched vocalizations

Contact Information
Annette Carey, Project Director
(304) 558-2696, [email protected]
 Ruth Ann King, Project Coordinator
(304) 558-2696, [email protected]

Mentors
 Tammy Belt
Cell: (304) 646-1697, [email protected]
 Jamie McBride
Cell: (540) 533-8303, [email protected]
Contact Information
Continued
Mentors continued:
 Bridget Bailey
Cell (304) 419-3187, [email protected]
 Kathy Quesenberry
Cell (304) 952-1099, [email protected]
Partners:
 Jennifer Cook
Cell (304)517-8767,[email protected]
 Tina Foster
Cell (304)517-4079, [email protected]
Contact Information
Continued
Partners Continued:
Kyle Heeter
Cell 1-304-573-4775,[email protected]
 Anita Nesland
Cell 1-304-614-3490, [email protected]
 Amie Cook Smith
Cell 1-304-784-6873, [email protected]
