Refraction and motor functions Orientation and lenght of lines Motion perception and VField Picture...

Refraction and motor functions

Orientation and lenght of lines

Motion perception and VField

Picture perception&recognition

&

OUR GOAL

to understand each child’s

visual functioning

Children with CVI

OUR GOAL: to understand - the quality of the image - the use of information in higher visual

functions

- the role of vision in development and education

The effect of visual impairment varies in different tasks. Visual disability is task dependent.

Visual Impairment

affects four main areas:• Communication

• Orientation & movement

• ADL, daily living skills

• Sustained near vision tasks

Four-leafed clover ofVISION

Visual Impairment

Basic questions:How does vision affect this function?

How is vision going to affect development of this function?

Does the child have compensatory techniques? How do I teach them?

Visual Impairment

Basic questions:How does vision affect this function?How is vision loss going to affect

development of this function?Does the child have compensatory

techniques? How do I teach them?How do I help the child to develop compensatory techniques?

Refraction and motor functions

Orientation and lenght of lines

Motion perception and VField

Picture perception&recognition

Visual cortex V1 & V2

Visual cortex V1 & V2

Visual cortices

posterior parietal

inferotemporal

frontal eye-hand coordination

spatial awareness

recognition

CVI Often a part of larger brain damage >>

thus

Cerebral visual impairmentor

Brain damage related

visual impairment

Brain damage related VI

Caused by:

- lesions in visual pathways

- cortical lesions, visual and other

- subcortical lesions

- leads to uneven profile of visual functions, some good, some poor

important in assessment of children with intellectual disabilities

CVI - Behaviours

- VARIATION in visual behaviour

- effect of basic disorder

- effect of medication, wakefulness

- misunderstanding the functions

easy to us, difficult to the child

CVI - Behaviours

- VARIATION in visual behaviour

- speech as compensatory function

CVI - Behaviours

- VARIATION in visual behaviour

- speech as compensatory function

- plays with adults, not with children

CVI - Behaviours

- VARIATION in visual behaviour

- speech as compensatory function

- plays with adults, not with children

- clings to parents in crowded places

CVI - Behaviours

- VARIATION in visual behaviour

- speech as compensatory function

- plays with adults, not with children

- clings to parents in crowded places

- uses colours for recognition

CVI - Behaviours

- VARIATION in visual behaviour

- speech as compensatory function

- plays with adults, not with children

- clings to parents in crowded places

- uses colours for recognition

- may learn letters early, only short words

CVI - Behaviours

- VARIATION in visual behaviour

- speech as compensatory function

- plays with adults, not with children

- clings to parents in crowded places

- uses colours for recognition

- may learn letters early, only short words

- starts drawing late or never

CVI – Behaviours 2

- stops at thresholds and shadows

- depth perception

- perception of surface qualities

CVI – Behaviours 2

- stops at thresholds and shadows

- does not look at, ”avoids eye-contact”

CVI – Behaviours 2

- stops at thresholds and shadows

- does not look at, ”avoids eye-contact”

- peripheral vision better, central scotoma

CVI – Behaviours 2

- stops at thresholds and shadows

- does not look at, ”avoids eye-contact”

- peripheral vision better, central scotoma

- gets lost in familiar places

CVI – Behaviours 2

- stops at thresholds and shadows - does not look at, ”avoids eye-contact” - peripheral vision better, central scotoma - gets lost in familiar places - gets angry if objects are moved

CVI – Behaviours 2

- stops at thresholds and shadows - does not look at, ”avoids eye-contact” - peripheral vision better, central scotoma - gets lost in familiar places - gets angry if objects are moved

- uses siblings and adults for help

CVI

A list

of

typical behaviours

does NOT

help us to understand a child.

When a child has an unusual behaviour,

describing it is not enough.

When a child has an unusual behaviour,

describing it is not enough.

Try to find out WHY the child has that behaviour.

Consider other impairments.

Consider the situation.

Fixation & accommodation

Length & parallel lines

Angle & cross

Pen and spasticity

Parallel v. crossing lines

Eye-hand coordination

Cognitive visual functions Discrimination of orientation of lines

Discrimination of size/length of lines

Detection & discrimination of movement

Perception of texture, surface qualities

Object / background, Depth

Recognition of faces, expressions

Recognition of geometric forms

Perception of pictures

Spatial awareness, eye-hand coordination

CVI

Diagnose and therapy: - team, transdisciplinary - tests are used by everyone - observation - structured play situations - repeated assessment

Transdisciplinary Diagnose

In the assessment of children withbrain damage related vision loss: - ophtalmologist: anatomy, refraction

- teacher, therapist: observations, testing

- neurologist: dg, neurologic impairements

- neuropsychologist: cognitive vision video documentation

Assessment of functional vision

- basic information from the eye hospital

structure of the pathways, refraction,

glasses (under- or overcorrection?)

VA, VF, CS, CV, VAd, motor functions

Assessment of functional vision

- basic information from the eye hospital structure of the pathways, refraction, glasses (under- or overcorrection?) VA, VF, CS, CV, VAd, motor functions - testing of all visual functions in play and teaching situations, effect of other impairments and disorders

Transdisciplinary assessment

School assistant

Assessment of functional vision

- basic information from the eye hospital structure of the pathways, refraction, glasses (under- or overcorrection?) VA, VF, CS, CV, motor functions - testing of all visual functions in play and teaching situations, other impairments

- effect of posture and facilitation in children with severe motor problems

Influencing factors

Four children

• Prematurely born girl with problems in recognition of faces + other impairments

• Boy with severe CP, poor head control and poor oculomotor functions, good VA, CS,VF

• Girl with extreme hypotonia, insufficient accommodation, slow hand movements

• Boy with deletion syndrome, central scotoma, hearing problems, delayed development

Recognition of faces

Re-cognition:

- the facial features are seen

- a template is formed in memory

- the face is seen again

- template is found and matched

Periventricular leukomalasiaNext to ventricle loss of white matter

PVL

Matching pictures

Recognising pictures of faces

Photophobiadue to optic atrophy

Glasses are tested both outside and inside

Photographic memory

Severe hypotoniano functions without good support

Spatial conceptseye-hand coordination good when supported

Correction of reading distanceaccommodation insufficiency

Early developmental level

Strabismus

Testing in play situations

Findings• A rare deletion in chromosome 2• MRI not yet possible, anesthesia dangerous• Optic discs greyish; hearing =? CAI?• Good orientation in space, explores• Reaches for and grasps• Notices grey on grey• Strabismus LE, does not seem to alternate• Seems to fixate at hair line > central scotoma• RE –3.0, LE –5.0 - -6.0 without cycloplegia• Vision for communication in lecture V.

Four children

• Prematurely born girl with problems in recognition of faces + other impairments

• Boy with severe CP, poor head control and poor oculomotor functions, good VA, CS,VF

• Girl with extreme hypotonia, insufficient accommodation, slow hand movements

• Boy with deletion syndrome, central scotoma, hearing problems, delayed development

Severe multihandicap

• Highly individual• Difficult to assess, formal tests may not function

- detection tests do not measure form perception

• Pleasure of seeing may be lacking- no drive to look, learning through vision does not occur

• Directing attention; comprehension; memory• No prior confirmation with mouth and hands• The child may be blind; hearing/ tactile/ haptic

- Try with very high contrast visuo-tactile toys, not too long.

”Levels” of CVI

• There are no general ”levels” of CVI• Each cognitive visual function needs to be

assessed individually

”Levels” of CVI

• Each cognitive visual function needs to be assessed individually

• We do not assess all functions during the first examination, repeated assessments needed

”Levels” of CVI

• Each cognitive visual function needs to be assessed individually

• We do not assess all functions during the first examination, repeated assessments needed

• Accept variation in results in CVI, try to find out the causes of variation

”Levels” of CVI

• Each cognitive visual function needs to be assessed individually

• We do not assess all functions during the first examination, repeated assessments needed

• Accept variation in results in CVI, try to find out the causes of variation

• Train to improve weak functions, find compensatory strategies, build on strong functions.

”Levels” of CVI• Each cognitive visual function needs to be assessed

individually• Do not believe that you have assessed all functions during

the first examination• Accept variation in results as a norm in CVI, try to find the

causes of variation• Train to improve weak functions, find compensatory

strategies, build on strong functions

• Never generalise, children with CVI are highly individual in their functions and experiences. Consider other impairments.

• Consider techniques of blind people.

CVI

• Impaired cognitive vision is most often part of brain damage related visual impairment that involves also motor functions and/or hearing.

• When CVI occurs without other neurologic problems, it is often wrongly diagnosed as ”autistic features” or the child is said to see ”when (s)he wants to see”.

OUR GOAL

to understand each child’s

visual functioning

Four-leafed clover ofVISION

Visual Impairment

Basic questions:How does vision affect this function?How is vision going to affect

development of this function?Does the child have compensatory

techniques? How do I teach them?How do I help the child to develop compensatory techniques?

Vision for Special Education

- consider ALL areas of functioning at preschool and school age

not only

- vision for academic subjects

Vision

is

a learned function

Learning to see

Hands (to midline and into mouth)

Mouth (a reliable source of information)

Tactile information, tasting, smell Vision (confirmed by other modalties)

Multimodal memory Recognition

Finding hands

Because

vision

is

a learned function

start early intervention early!

CVICerebral visual impairment

Brain damage related visual impairment