Title: Cortical Visual Impairment Diagnostic and Therapeutic Considerations
1 Cortical Visual Impairment Diagnostic and
Therapeutic Considerations
2Monets Garden
- The Japanese Foot Bridge
- My bad sight means I see everything through a
mist, Even so it is beautiful, and thats what I
would like to show.
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41899
51900
61923
7Pediatric Blindness
- 1.5 million children blind
- Every year ½ million children become blind
- Often blind children have other disabilities such
as intellectual delays, seizure disorders,
hearing and speech impairment - Children with disabilities may have up to 50
visual system pathology
8Pediatric BlindnessWorldwide
- CVI (Brain)
- ROP
- Cataract
- Glaucoma
- Trauma
- Inherited disease
- Infection
9Pediatric Blindness Worldwide
- Global Corneal scarring
- Poor countries Corneal scarring from vitamin A
deficiency, measles, ophthalmia neonatorum - Middle income Retinal conditions, Inherited
retinal dystrophies, ROP - High income CNS associated, Retinal dz
10Pediatric BlindnessWhat can we do?
- Prevention
- Treatment of existing disease
- Correct Refractive errors
- Rehabilitation trans-disciplinary
- ½ of all blind children can have vision improved
to read normal size print improved by optical
means
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12Chetana FoundationIndiaI-Count
- 109 with VI and CP
- 42 ONA
- 24 CVI
- 12 DVM
- 12 Myopia
- ONA Optic Nerve atrophy
- CVI Cortical Visual Impairment
- DVM Delayed visual impairment
- VI Visual Impairment
- MR Mental Retardation
- 125 with VI and MR
- 88 ONA
- 23 CVI
- 14 DVM
- 11 Myopia
13American Printing HouseBabies Count (
preliminary)
- 2155 surveyed
- CVI 24
- ROP 17
- ONH 10
- 50 with additional disabilities
14Chetana FoundationIndiaI-Count
- Seizure Disorders
- 39 ONA
- 30 CVI
- 12 DVM
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16Why is Vision Important?
- Contributions to Learning
- Vision 83
- Hearing 11
- Smell 3.5
- Touch 1.5
- Taste 1.0
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18VIISA1.1.Ch15.T11
19How do you learn to smile?
20Cortical Visual Impairment
- We are moving from ocular blindness to brain
blindness. - Creig Hoyt MD
21clarity
- Myopia
- Astigmatism
- Cataracts
- www.chetana.in.org
- N Jacob PhD
22completeness
- Optic atrophy
- Colobomas
- www.chetana.in.org
- N Jacob PhD
23comprehension
- CVI
- DVM
- www.chetana.in.org
- N Jacob PhD
24Compensating accommodationDr. Lea Havaringen
25Motor Skills Visual Impairment
- Almost all children with significant reductions
in visual acuity will have motor delays - Vision drives motor skills
- Low tone
- Poor coordination
- Ref. Carey Matsuba MD Vancouver
26Cognitive Skills
- Skills are highly dependent on vision
- In the presence of visual acuity that is poor,
children will have difficulty - With low vision states, it is dependent upon
cause - Ref. Carey Matsuba MD Vancouver
27Hearing Loss
- More common in the presence of genetic disease
- CHARGE, Norries, Ushers
- Children with visual impairment have a higher
association - Dual sensory loss will affects programming
- Ref. Carey Matsuba MD Vancouver
28Cortical Visual Impairment
-
- Epidemic of multi-handicapped, blind children due
to improvements in medical technology - Has to be a different teaching strategy.
- 4-8X more costly to educate than those with only
visual impairment or blindness. This will be a
huge cost to families, communities, and society.
These children are less likely to live
independently and financially support
29- Visual disability resulting from either an insult
to the brain or how the brain organization became
configured during prenatal development. - If affects how one understands the visual
information received by the eyes. - It is now the leading cause of vision impairment
in young children. - Vision loss varies from mild to severe, depending
on when, where, and the intensity of insult to
the brain. White-matter lesions are worse than
gray-matter lesions. - For those who show some visual responses during
infancy, prognosis for increased functional use
of vision is good. Progress depends on
neurological stability of the brain and
environmental support. - Many may use vision as their primary information
gathering sensory modality when they are older. - A range of visual functions may be affected.
VIISA1.1.Ch15.T7a
30- 8. Damage to thalamus affects childs ability
to focus easily overloaded by sensory
information. - 9. It does not get worse. It stays the same,
but more often gets better because damage is
usually incomplete and because of the plasticity
of the young brain. - 10. May occur with optical visual impairments
(e.g., ONA, ONH, ROP). - 11. Children with CVI span the intellectual
range. - 12. Intervention should begin early while brain
has plasticity and visual functioning can be
enhanced. - 13. Causes Complications of prematurity (brain
bleeds in ventricles), trauma, infections,
maternal substance abuse, oxygen deprivation,
seizures, hydrocephalus, brain tumors and
cysts. - 14. Other disabilities that occur with CVI may
be seizures (50), CP (53), ROP (20),
neurological disorders (75). - 15. Other vision problems (nystagmus,
strabismus, PVL).
VIISA1.1.Ch15.T7b
31Diagnosis of CVI
Dr. Christine Roman
- Child has a normal eye examChild has a medical
history of neurological problemChild exhibits
many of the key characteristics of CVIParent
interview
VIISA1.1.Ch15.T10
32Diagnosis of CVI
Dr. Lea Hyvarinen
- Functional Visual Evaluation
- Refraction, motor function, motion perception,
visual field assessment, picture perception and
recognition - Are the oculomotor functions sufficient to
allow undisturbed use of vision? What is
the quality of the image that the child has?
Which cognitive visual functions are there and
which are not at an appropriate age level? If
the child has behaviors typical to CVI, what is
the possibility that they are caused by problems
in other than visual functions?
VIISA1.1.Ch15.T10
33Diagnosis of CVI
Dr. Lea Hyvarinen
- Functional Visual Evaluation
- DIAGNOSIS AND ASSESSMENT BY TRANSDISCIPLANARY
TEAM OF CHILDS OPHTHALMOLOGIST, TEACHERS,
PT,OT,NEUROLOGIST, PSYCHOLOGIST
VIISA1.1.Ch15.T10
34Diagnosis of CVI
Dr. William Good
- VEP with variable lighting using either grating
or vemier acuity stimulus - MRI helps give information of prognosis and where
damage is - Rec exam by neurologist and EEG
VIISA1.1.Ch15.T10
35Diagnosis of CVI
Dr. Gordon Dutton
- Use of structured clinical history taking with
the family (www.nature.com/eye 2003)
VIISA1.1.Ch15.T10
36Processing disabilitywith or without motor
disabilitywith or without auditory
disabilityvarying intellectual functions
37VIISA1.1.Ch15.T1
38Corpus callosumDr. Lea Hyvarinen
39Corpus callosumDr. Lea Hyvarinen
40Brain Ventricles
Ventricles
Lateral Ventricle
3rd Ventricle
4th Ventricle
Optic Radiations
VIISA1.1.Ch15.T8
41Optic radiationDr. Lea Hyvarinen
LGN
42Ventral dorsal streaminferotemporal parietal
stream(ref Lea Hyvarinen MD)
dorsal
frontal
retinocalcarine
tectal
ventral
43Ventral Dorsal StreamDr. Lea Hyvarinen
44Processing disability
- Primary visual cortex ( V5)
- - coding direction and length of lines,
color, motion - Ventral stream functions
- - recognition face, landmarks, objects,
form - - facial expressions, body language,
pictures, - object background, surface qualities,
textures - Dorsal stream functions
- - orientation in space, eye-hand
coordination - Since the posterior parietal and
inferotemporal areas are far apart, some visual
functions may be lost in one of the main visual
associative area without loss of visual functions
in the other. - Dr. Lea Hyvarinen
45What is Cortical Visual Impairment
- Brain blindness
- Damage to brain dealing with processing and
integrating visual function - Temporary or permanent
- Severe VI to blindness
- Neurological impairment
46Etiologies of CVI
- Perinatal Hypoxia
- Cerebral vascular accident
- Meningitis
- encephalitis
- Acquired hypoxia
- Hydrocephalus
- Prematurity
- Intracranial cyst
- head trauma
- seizures
- In-utero drug exposure
- 9.4 no etiology
47VIISA1.1.Ch15.T2
48Understanding CVI
- the fact that there are parallel visual pathways
makes it possible for some parts of the brain to
receive visual information when other parts are
damaged - the brain cortex has more than 30 specialized
areas that handle specific parts of visual
information. - LeaCVIpositionpaper
49Pathways for VisualInformation in the Brain
Parietal Lobe
Frontal Lobe
Optic Tract
LateralGeniculate Nucleus
Dorsal Stream
Calcarine Path
Chiasm
Optic Nerve
Optic Radiations
Parvocellular
Tectal Path
Ventral Stream
Magnocellular
Temporal Lobe
Pulvinar
Superior Colliculus
Dr. Lea HyvarinenHelsinki, Finland, 2004
VIISA1.1.Ch15.T3
50Prognosis
- V1 injury pie-shaped injury to primary visual
area - full term infants with hypoxic events, near
drowning - Child looks blind, often use peripheral vision
- Support by isolating objects visually giving
incentive to use vision - Good possibility of visual recovery
- Hoyt, 1999
51Prognosis
- Congenital CVI
- Especially when caused by hypoxia ischemia,
poor prognosis - Acquired CVI
- 60 70 recovery when caused by hypoxia/ anoxia
- Post meningitis, lower level of recovery
- Visual recovery can occur without associative
cortex improvement
52Prognosis
- V2 injury involvement of optic radiations due to
PVL, can progress to involve V3 - Very premature or low birth weight infants
- Child may have motion perception may have
nystagmus and ocular-motor issues often have
motoric involvement or CP - Use movement to elicit maintain visual
attention - Limited possibility of visual recovery
- Hoyt, 1999
53Prognosis
- V3 injury posterior diffuse cerebral injury
- Prematurity hypoxic injuries that result in
atrophy in large parts of the cortex. Motor
sensory issues present. Good cognition often
present - V4 injury diffuse cerebral impairment
- Affects colour vision
- Hoyt, 1999
54Neonatal Brain Injuries
- PremiesHypoxia
- Mature oligodendtires and subplate neurons
resistant to hypoxia - Subplate neurons are the transmitters between
thalamus and visual cortex - Periventricular leukomalacia
- Decrease volume of periventricular white matter
- Ventriculomegaly with irregular outlining of body
and trigone of lateral ventricles - Deep, prominent sulci
- Increase in periventricular signal
- Corpus callosum thinning
-
- Full Term Hypoxia
- Neurons deep in gray nuclei
- Nitric oxide synthase resistant
- Wedge shape in visual cortex
- Enlarged ventricles because of decrease in brain
tissue
55Cortical Visual Impairment
- PVL (Premies)
- 50 Nystagmus, strabismus
- 20-40 Optic Nerve abnormalities with spastic
diplegia - Visual recovery less than term infant
- Transynaptic degeneration leads to increase in
optic nerve cupping
- Cortex injury (full term)
- Nystagmus, strabismus unusual
- Optic atrophy 10-20
- Spastic quadriplegia
- Better visual recovery
56Visual Perceptual Impairment in Brain Injuries
- Leukomalacia (Premies)
- Inability to walk, diminished peritrigonal white
matter, high degree of gliosis, cortical damage
associated with poorer visuo-perceptual skills - Enlarged ventricles associated with both
cognitive, perceptual, and motor problems
reflecting the considerable extent of brain
damage - Children with leukomalacia at considerable risk
of visual perceptual impairment
- Parenchymal hemorrhages
- Right sided hemorrhages at risk although function
much better due to better motor and cognitive
skills - Children with perinatally acquired parenchymal
hemorrhages have better visual perceptual skills
than those with leukomalacia. - Brain Dev. 2004 Jun26(4)251-61
57Cortical Visual ImpairmentAssociated Disabilities
- 65.3 at least one anterior pathway deficit
- Esotropia, exotropia, gaze palsy, nystagmus,
optic nerve atrophy, refractive error(gt3.00 or lt
-3.00), retinal disease
- 75 at least one neurological defect
- 52.9 seizures
- 58.2 Cerebral Palsy
58VIISA1.1.Ch15.T9
59Cerebral visual impairment in periventricular
leukomalacia MR correlation
- American Journal of Neuroradiology, Vol 17, Issue
5 979-985
C Uggetti, MG et alServizio di
Neuroradiologia, IRCCS Instituto Neurologico
Fondazione C. Mondino, Pavia, Italia.
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68How do we intervene
- Do not delay intervention for diagnosis
- Similar interventions for infants with CVI,
autism spectum disorder (ASD), mental retardation
early - Early multi-disciplinary intervention
69How do we intervene
- Future
- Look at our statistics
- Monitor outcome
- International database
- Multi-disciplinary training course
70Functional Vision
- Monets story shows us that eyesight and
functional vision may differ - Our role as health care providers is to offer
each child, each person the chance for developing
to best potential
71Functional Vision
- Each child sees in a unique way despite the
pathology that exists - Recovery of visual functioning is never as if
it had developed typically - The childs ability to compensate for
neurological deficits in unknown
72Functional Vision
- The child and family will remember every word you
say for the rest of their life, how you speak to
them, how you touch the child
73Functional Vision
- Each child deserves the right to safe, happy,
productive life
74Trans-disciplinary Team
- Just do it!
- Learn how to play with the child in your
assessment, make it fun - Watch what you say, your words will have an
impact on this child for a lifetime - Dont be afraid to refer to others on your team
- Communicate in a common language
- Remember how you learn to smile
75References
- Carey Matsuba, MD, Vancouver
- Lighthouse International, New York, Pediatric Low
Vision Course - Vision 2020 website
- American Academy of Ophthalmology
- Preferred Practice Patterns and teaching
slides
76References
- Werner, David Disabled Village Children
- available on-line at www.healthwrights.org
- Zinkin, Pam and McConachie,H Disabled Children
and Developing Countries - www.blindbabies.org
- www.chetana.org.in
- www.orbis.org e-resources, Pediatric Low Vision
- http//www.lea-test
- http//www.solobambini.com
- Journal of Community Eye Health
- Lea Hyvarinen CVI Policy Paper
77Additional centers collecting data
- Centro Anne Sullivan Del Peru-CASP
- Centro Anne Sullivan Du Brasil-CASB
- Rio de Janiero and Ribieron Preto
- New Hope School, Santa Maria de Jesus,
Guatemala -
- Salina Regional Health Center, Salina
- Kansas USA Early Childhood
- Intervention Program (0-3)
- Kansas State School for the Blind, USA
Eye-See - Hope for the Blind, Zaria, Nigeria
78Acknowledgments for information and slides
- Carey Matsuba,MD Univ of British Columbia
- Dr. Anne Nielsen, Kansas State School for the
Blind - Creig Hoyt MD Lecture, Dec. 2005 Pediatric
Conference, Kingdom of Bahrain - VIISA Training Course, SKI-HI Institute,Utah
- www.blindbabies.org
- www.chetana.org.in
- www.lea_test
- www.orbis.org e-resources, Pediatric Low Vision
79THANK YOU
- Chetana Foundation and Dr Namita Jacob
- Ophthalmology Society of Nigeria
- Monet and his story of perseverance
80Thank you
- All the children and families who have been my
greatest teachers in compassion and patience - Hope for the Blind
- Liliane Fonds
- Dr. Anne Nielsen