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

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Presentation on theme: "Refraction and motor functions Orientation and lenght of lines Motion perception and VField Picture perception&recognition &"— Presentation transcript:

1 Refraction and motor functions Orientation and lenght of lines Motion perception and VField Picture perception&recognition &

2 OUR GOAL to understand each child’s visual functioning

3 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

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

6 Visual Impairment affects four main areas: Communication Orientation & movement ADL, daily living skills Sustained near vision tasks

7 Four-leafed clover of VISION

8 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?

9 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?

10 Refraction and motor functions Orientation and lenght of lines Motion perception and VField Picture perception&recognition

11 Visual cortex V1 & V2

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13 Visual cortices posterior parietal inferotemporal frontal eye-hand coordination spatial awareness recognition

14 CVI Often a part of larger brain damage >> thus Cerebral visual impairment or Brain damage related visual impairment

15 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

16 CVI - Behaviours - VARIATION in visual behaviour - effect of basic disorder - effect of medication, wakefulness - misunderstanding the functions easy to us, difficult to the child

17 CVI - Behaviours - VARIATION in visual behaviour - speech as compensatory function

18 CVI - Behaviours - VARIATION in visual behaviour - speech as compensatory function - plays with adults, not with children

19 CVI - Behaviours - VARIATION in visual behaviour - speech as compensatory function - plays with adults, not with children - clings to parents in crowded places

20 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

21 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

22 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

23 CVI – Behaviours 2 - stops at thresholds and shadows - depth perception - perception of surface qualities

24 CVI – Behaviours 2 - stops at thresholds and shadows - does not look at, ”avoids eye-contact”

25 CVI – Behaviours 2 - stops at thresholds and shadows - does not look at, ”avoids eye-contact” - peripheral vision better, central scotoma

26 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

27 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

28 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

29 CVI A list of typical behaviours does NOT help us to understand a child.

30 When a child has an unusual behaviour, describing it is not enough.

31 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.

32 Fixation & accommodation

33 Length & parallel lines

34 Angle & cross Pen and spasticity

35 Parallel v. crossing lines

36 Eye-hand coordination

37 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

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

39 Transdisciplinary Diagnose In the assessment of children with brain damage related vision loss: - ophtalmologist: anatomy, refraction - teacher, therapist: observations, testing - neurologist: dg, neurologic impairements - neuropsychologist: cognitive vision video documentation

40 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

41 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

42 Transdisciplinary assessment

43 School assistant

44 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

45 Influencing factors

46 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

47 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

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49 Periventricular leukomalasia Next to ventricle loss of white matter PVL

50 Matching pictures

51 Recognising pictures of faces

52 Photophobia due to optic atrophy Glasses are tested both outside and inside

53 Photographic memory

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55 Severe hypotonia no functions without good support

56 Spatial concepts eye-hand coordination good when supported

57 Correction of reading distance accommodation insufficiency

58 Early developmental level

59 Strabismus

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61 Testing in play situations

62 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 – without cycloplegia Vision for communication in lecture V.

63 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

64 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.

65 ”Levels” of CVI There are no general ”levels” of CVI Each cognitive visual function needs to be assessed individually

66 ”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

67 ”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

68 ”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.

69 ”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.

70 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”.

71 OUR GOAL to understand each child’s visual functioning

72 Four-leafed clover of VISION

73 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?

74 Vision for Special Education - consider ALL areas of functioning at preschool and school age not only - vision for academic subjects

75 Vision is a learned function

76 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

77 Finding hands

78 Because vision is a learned function start early intervention early!

79 CVI Cerebral visual impairment Brain damage related visual impairment


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