Transcript Slide 1

Cortical Visual Impairment and
other Eye Conditions in Children
with Multiple Disabilities
By
Chris Marshall
Education Consultant for Visual Impairment
REACH
Content
• Eye conditions common in children with multiple
impairments
• The visual system, how it works - WOW
• What is CVI
• Assessment
• Multi sensory learning
• Assistive technology for MDVI
• Team approach
Multiple disabilities with a visual
impairment. Associated Eye
Conditions
• Cerebral Palsy – Hyperopia / Myopia,
Esotropia, nystagmus,
• Down syndrome – Hyperopia / Myopia
• Other conditions include Optic nerve
atrophy, cataract, microphthalmos,
colobomas, ROP,
• CVI or Cortical Visual Impairment
The Visual System – How it works.
Just think about it
• The lens in the front of
the eye focuses the light
• An upside down and back
to front picture is formed
on the retina
• The retina is made up of
millions of cells called
rods and cones – the
cones for detecting light
and color and the rods for
seeing in the dark.
• Light is converted into electrical impulses
• The electrical signal is split into two systems – motion
and detail
• Information runs through fine threads to optic nerve
• The two nerves combine together then cross in such a
way as the picture seen on right side by both eyes is
processed by left brain WOW
What is CVI – In simple terms
• Some estimates suggest that up to 60% of
the brain is devoted to vision
• CVI is a neurological disorder
• It results in an inefficient visual sense
caused by widespread brain disturbance
• Every child with CVI is different
The seeing brain
• Damage to Dorsal
stream make it
difficult to get around
- use Stairs – step
onto sidewalks –
reach forward and
grab a drink
• Damage to Ventral
stream makes it
difficult to recognize
faces, objects and
places
CVI Characteristics
• Effects vary depending on which part of
the vision brain is damaged.
• Reduced visual acuity – poor fixation and
ability to follow and maintain gaze
• Ocular health may be normal
• Stabismus and refractive error common
• May light gaze or be photophobic
Assessment tools
• In order to support a student we need to
gather information on what they can see
• The Christine Roman assessment is a
good tool – looks at specific characteristics
• Other methods include interviews with
parents, teachers and staff - observations
and more formal tests
The Ten Christine Roman
Characteristics
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Color preference
Need for movement
Visual latency
Visual field preferences
Difficulties with visual complexity
Light-gazing / non purposeful gaze
Difficulty with distance viewing
Atypical visual reflexes
Difficulty with visual novelty
Absence of visually guided reach
Multi Sensory Learning
• 75% of all learning comes from the visual
sense. Many VI children have delayed
speech and mobility
• To help with sensory integration combine
hearing, taste, smell, touch and movement
such as vestibular and proprioceptive
senses.
• Consider use of objects of reference
sound cues and object calendars
Practical Ideas
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Tac Pac
Light box
Sensory studio
Visual stimulation
Fluorescent materials and
black light
Drama games
Body awareness
Digital camera
Computer work
Music
Sensory room / Light box
• A sensory room is a
great resource to
develop visual
response and to work
on individual goals
such as tracking,
fixation, color as well
as body awareness,
language and cause
and effect
The Light Box Kit
• Comes in three levels with materials and a complete
teacher guide
• Can be used to develop individual programs
Low tech and simple
• Routines are great – especially with
participation for the student
• Get down to eye level and close
• Consider the environment and positioning
• Use songs and music for fun and to help
with transitions
• Use your name and the name of the child
Orientation and Mobility
• Remember to make
contact with child in
wheelchair and let
them know where
they are going!!!
• Point out landmarks and sensory cues along
way
• Use directional language
• Make trip purposeful – job or reward at
destination
Water and textures
Experiencing sand or other
materials
Assistive Technology
• AT is a tool that can deliver instructional
solutions and enhance a student’s active
participation in tasks and activities
• AT can include – switches, Augmentative
communication, mounting devices, power
link switch box, battery interrupters,
computer software, touch screens
Adapted Computer
• Black boarder around
screen
• Intellikeys with tactile
overlay
• Music as a motivator
• Touch screen
• Speech recognition
• Screen readers and
magnification
Collaboration
• Learning team to include parents, class
teacher, vision teacher, OT, speech, O & M
specialist, physical therapist and TA’s
• Multi disciplinary assessment – evaluation
of child’s strengths and disabilities
• Develop a meaningful and effective
program
• Looking at the whole child to include social
and emotional development
Useful Websites
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http://www.pisp.ca/
http://www.vision.alberta.ca/
http://www.viscotland.org.uk/
http://www.prcvi.org/
http://www.setbc.org/
http://www.northerngrid.org/ngflwebsite/se
n/Menu-L.htm