Cortical Visual Impairment and other Eye Conditions in Children

with Multiple DisabilitiesBy

Chris MarshallEducation 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

• 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

• 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

• 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/sen/Menu-L.htm