Characteristics of CVI. Function of vision No one place in brain is responsible Organized in different places of the brain.

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 examBrain injuryUnique 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

Range

3-4

Range

5-6

Range

7-8

Range

9-10May localize briefly but no prolonged fixations on objects or faces.

Overly attentive to lights or possibly ceiling fans

Less attracted to lights – can be redirected to other targets

Light is no longer a distractor

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

Range3-4

Range5-6

Range 7-8

Range9-10

Objects viewed are generally single color

Has a “favorite” color

Objects may have 2-3 colors

More colors, familiar patterns regarded

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

Range

7-8

Range

9-10Prolonged periods of visual latency

Latency slightly decreases after periods of consistent viewing

Latency present only when student is tired, stressed, or over stimulated

Latency rarely present

Latency resolved

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

Range3-4

Range5-6

Range 7-8

Range9-10

Only favorite or known objects solicit visual attention

May tolerate novel objects if they share characteristics of familiar ones

Use of “known” objects to initiate looking sequence

Selection of objects less restricted, requires 1-2 sessions of “warm up” time

Selection of objects not restricted

Visual Reflexive Responses

Visual Reflexive Response

Response to Visual Threat

Visual Reflexive Responses

Range 1-2

Range3-4

Range5-6

Range 7-8

Range9-10

No blink in response to touch and/or visual threat

Blinks in response to touch but response may be latent

Blink response to touch consistently present.

Visual threat response

intermittently present

Visual threat response consistently present (both near 90% resolved)

Visual reflexes always present, resolved

MOVEMENT

Objects viewed have movement or reflective property

Way to jump-

start 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

Movement 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

Range

7-8

Range

9-10

Distinct field dependency

Shows visual field preference

Field preferences decreasing with familiar inputs

May alternate use of right and left visual fields

Visual fields unrestricted

Visual Motor

Visual targets need to be simple, non-complex, 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

Range

7-8

Range

9-10Look & 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

Look and touch occur in rapid sequence but not always together

Look and touch consistently

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.

Range5-6

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.

Range9-10

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 18-24 inches of his/her face.

May be result of increased complexity of visual array

“Distance Viewing” Across Ranges

Range

1-2

Range

3-4

Range

5-6

Range

7-8

Range

9-10

Visually attends in near space only

Occasional visual attention on familiar, moving or large targets at 2-3 feet

Visual attention extends beyond near space, up to 4-6 feet

Visual attention extends to 10 feet with targets that produce movement

Visual attention extends beyond 20 feet

Demon-strates memory of visual events

Progression of Resolution

Early ResolutionLight gazing, blink reflex

Mid Resolutioncolor, latency, novelty, visual threat, movement

Later ResolutionField, 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. Single color objects

2. Objects of preferred color

3. Objects that produce movement or are shiny

4. Objects presented against a simple background

5. Objects that are familiar

-Roman-Lantzy, 2005

Phase 2

Students generally require:1. Reduction of information when presented in 2

dimensionUse occluders or window cards to eliminate

excess detailHighlight 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 BeltCell: (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]