Cortical visual impairment: An educational perspective

1. Cortical visual impairment:An educational perspective Dr. Jane Erin The University of Arizona

3. Common characteristics of CVI Fluctuating vision Reliance on peripheral vision Attentiveness to movement Preference for red and yellow Preference for familiar rather than novel Difficulty with cluttered backgrounds Glancing away and then toward Potential for improvement over time Visual latency

4. Physical development Strong prognosis for visual improvement within first three years Possibility of some improvement up to 7 years Some children diagnosed with Delayed Visual Maturation regain functional vision Effects of intervention (as compared to maturation) are unknown

5. Cautions in interpreting the literature 1. Never� and �Always� are not appropriate for groups of students with CVI. These students show wide individual variation, and they rarely show all of the common characteristics.

6. 2. Educational programming should not be based on etiology Program decisions should be based on individual assessment, including the functional vision assessment. The diagnosis suggests global characteristics that help determine assessment, not specific interventions.

7. 3. Compensatory approaches may be as important as visual usage. Visual improvement may not result in integrated use of senses. Students may respond more immediately to information received through other senses.

8. Physiological assessmentsGood, W., Jan, J., Burden, S., Sknezenski, A., Rowan, C. (2001) Computed tomography (CT) can show type and location of damage. Magnetic resonance imagery (MRI) is more sensitive than CT scan. Visual evoked response (VEP) maps responses over a wider area and can be combined with an EEG (Electroencephalogram) for diagnosis.

9. Formal assessments can document estimated acuity. Assessments based on gaze shift and visual fixation can provide information about optimal function under controlled conditions.

10. Assessment Scale: The CVI Range Dr. Chris Roman, Marshall University, has developed a rating scale that identifies Characteristics of student Status of characteristics Levels 0-4: Building visual behaviors Levels 4-7: Embedding vision into function Levels 7-10: Resolution

11. Functional Vision Assessments Must be complete over several sessions, in different settings and at different times of day. Videotaping can be used to document initial session and reassess vision at regular intervals. Should involve familiar and unfamiliar objects and settings. Near and distance responses in central and peripheral fields should be noted.

12. Strategies for intervention(Morgan, in Lueck, 2004) Do vision activities at time when best visual function is observed. Simplify the task. Slow the presentation and provide plenty of response time before prompting. Make sure expectations are evident. Provide structure and consistency. Space the target materials to allow visual attention. Reduce background clutter and sensory information.

13. Environmental adaptations (Morgan, in Lueck, 2004) Control for glare Minimize florescent lighting Place student with back toward window Use indirect lighting Reduce irrelevant sensory information (e.g., background noise, odors) Enhance visual targets with color, light highlighting Reduce visual detail

14. Provide multisensory cues and reinforcement, according to child�s preference (Morgan, in Lueck, 2004) Add sound to the visual target. Create visual/tactile boundaries for task. Tap the child�s arm or body on the side of an approaching visual stimulus. Encourage the student to track visual information with a finger. Use verbal cues for the beginning and ending of a routine.

15. Key points Strategies can be useful with most students with multiple disabilities. Educational planning should be based on assessment and observation, not diagnosis. Consistent interventions with gradual generalization will be most successful.