1. Chapter 11 Vision and Visual Impairment
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

2.
Chapter 11 materials in Children with Disabilities, Seventh Edition, Online Course Materials. Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

3. Introduction Impaired vision in childhood
Can have detrimental effect on physical, neurological, cognitive, emotional development
Can occur as isolated disability or associated with other developmental disabilities
Must be identified and treated with effective medical and special education interventions
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

4. Structure and Function of the Eye
Structure problems can result in vision impairment or loss
Visual loss divided into disorders impacting
Transmission of light
Central visual field
Peripheral visual field
Refraction
Combination of issues
Ocular support problems can result in glaucoma
Ocular motility problems can result in strabismus (misalignment of the eyes)
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

5. Ocular Development
Structures that become eyes first appear at 4 weeks’ gestation
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

6. Visual Development Children with disabilities
Causes of developmental disabilities often influence visual system
One half to two thirds of individuals with developmental disability have significant occular disorder
Pediatric ophthalmologist should conduct exam as part of overall assessment for child with developmental disability
Amblyopia
Visual regression in healthy eyes
Must be identified and treated or the visual use is reduced, which can lead to educational disability
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

7. Common Disorders of the Eye in Children with Disabilities
Cataract—a defect in lens clarity, appearing as a white spot in pupil, that can cause amblyopia
Can require surgery
Isolated abnormality or part of syndrome or disease
Optic nerve hypoplasia—an optic nerve transmits impaired information
Decreased vision uncorrectable with glasses
Common cause of visual disability
Often associated with other developmental disabilities
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

8. Common Disorders of the Eye in Children with Disabilities (continued)
Retinopathy of prematurity (ROP)—vascular damage from incomplete blood vessel growth
Can result in vision loss
Screening for premature infants
Treated with laser application, but visual impairments often remain
Other retinal disorders—other disorders that affect the retina
Nonaccidental injury (shaken baby syndrome)
Congenital infections
Inborn errors of metabolism
Retinal tumors
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

9. Disorders of the Visual Cortex
Cortical visual impairment (CVI)
Caused by oxygen deprivation, infections of central nervous system, or traumatic brain injury
One of most common causes of visual impairment in the developed world
Behavior: mildly impaired to absent visual attention
Requires full ophthalmologic exam to rule out treatable causes
Delayed visual maturation (DVM)
Presents like CVI, but visual function improves spontan-eously in infancy as child’s overall development progresses
By 6–12 months, DMV infants often have normal or near-normal visual function
Visual stimulation important
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

10. Strabismus and Ocular Motility Disorders
Strabismus (misalignment of eye)
3%–4% of all children; 15% of former premature infants; 40% of children with cerebral palsy
Two forms: esotropia (cross-eyed) and exotropia (wall-eyed)
Causes amblyopia in children younger than 8 years of age; resulting neurological problems can be treated by surgery
Nystagmus (rapid jiggling back and forth of eyes as result of inability to fixate on objects)
Evaluation can include comprehensive pediatric ophthalmologic exam, electroretinogram, and neurological evaluation
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

11. Strabismus and Ocular Motility Disorders (continued)
Anomalous head postures (tilted or turned head)
Can be caused by strabismus and nystagmus
Should see ophthalmologist as part of evaluation
Strabismus surgery can reposition eyes
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

12. Refractive Errors in Children
Myopia—nearsightedness
The eye is too long or refracting mechanisms are too strong
Severe myopia requires eyeglass correction from infancy to expand vision
Hyperopia—farsightedness
The eye is too short or refracting mechanisms are too weak
Most common refractive error of childhood
Most children require no correction, but hyperopia of more than 4 diopters may require glasses
Astigmatism—eye does not focus on single point and image is blurred because surface of cornea is misshaped
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

13. Vision Assessment
Multidisciplinary vision assessment is critical in determining best interventions 
Parent perception
Clinical examination
Infants and nonverbal children
Blinking to a light
“Eye-popping” reflex
Directed vision
Red reflex testing
Fixating on and following objects
Toddlers and older children
Wall charts and picture cards
Matching games
Vision-testing machine
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

14. Blindness
Different definitions of blindness and low vision, but from functional standpoint:
Acuity or field numbers aren’t all-important
Individuals function differently with vision they retain
Care providers should avoid making judgments based solely on clinical measures
Important to talk to parents and school staff
Critical to understand the extent of limitations from the visual impairment
Causes of blindness
Cortical visual impairment, ROP, optic nerve hypoplasia
Other: traumatic brain injury, severe infections, tumors
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

15. Severe Visual Impairment
Clues:
Inability to visually fixate on parent’s face or brightly colored objects
Abnormalities in eye movements
Lack of blinking or response
Developmental delays appear dependent on amount of residual vision and the presence or absence of associated developmental disabilities
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

16. Interventions
Early interventions include clinical, rehabilitation, and educational aspects that increase skills in other senses, improve body concept and awareness, and promote locomotion and active environmental exploration
Home-based sessions with early childhood educator
School-based preschool programs
Optical aids and devices, braille, computers, audio
Assistive technology: voice recognition software, close circuit television, global positioning system
Genetic advances (e.g., gene-replacement therapy)
Multidisciplinary approach for children with multiple disabilities
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

17. Outcome for Children with Visual Impairment
Visual impairment can be progressive or nonprogressive
Outcome depends on
Amount of residual vision
Presence of associated disabilities
Motivation of child and family
Skills of child’s teacher and therapists
Chapter 11 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.