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Characteristics of CVI

Characteristics of CVI. Function of vision. No one place in brain is responsible Organized in different places of the brain. FUNCTIONAL USE OF VISION: Using vision to complete an activity within daily life. Not based on visual acuity

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Characteristics of CVI

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  1. Characteristics of CVI

  2. Function of vision • No one place in brain is responsible • Organized in different places of the brain

  3. FUNCTIONAL USE OF VISION: Using vision tocomplete an activity within daily life • Not based on visual acuity • Based on visual, individual and environmental characteristics.

  4. What is CVI? • CVI is a condition in which the eye works but the part of the brain which interprets the signals provided by the eye does not. This will cause the child to have difficulty using visual input he/she is receiving. • CVI is not an indication of the child’s cognitive ability.

  5. Differences between Ocular and Cortical Visual Impairment • CVI: child may see accurate visual image, but can’t interpret it accurately • Ocular: child has difficulty obtaining good visual image, but can process and interpret image accurately when enough information is present • Some children have both (Levack, 1991)

  6. Let’s talk about CVI • Child has difficulty using visual input he/she is receiving. • CVI gets better or it gets worse. It can seem to vary from day to day. • CVI is suspected when: Normal eye exam Brain injury Unique characteristics present

  7. Presence of the unique CVI characteristics

  8. Early Resolution Light Gazing Visual Reflex Response (touch) Mid Resolution Color Latency Visual Novelty Visual Reflex Response (threat) Movement Later Resolution Visual Field Preference Visual Motor Complexity Target Array Complexity Distance Viewing Characteristics of CVI

  9. Light Gazing • Staring at lights or light sources is often observed; may also be attentive to ceiling fans. • May be difficult to redirect child’s attention away from a light source. • Sources of light should be positioned behind child. • When lighted toys or objects are used the light should be used to accentuate or highlight the item. Toys which have light and music should not be used with children in this phase.

  10. “Light Gazing/Non Purposeful Gaze” Across Ranges

  11. Color: • Items typically need to be a single color. • May need to use child’s preferred or favorite color. • Once child is looking at a variety of single color items may need to use favorite, or preferred color, to initiate looking when child is tired or engaged in activities which may challenge other areas (i.e.: motor) at the same time.

  12. “Color” Across Ranges

  13. Latency • In Phase I it may take the child extended periods of time to demonstrate a visual response. • Child may demonstrate a delay in using vision to “look at” a target most of the time when a new item is presented or a new activity starts. • Allow the child multiple opportunities and extended periods of time to demonstrate a visual response. • Latency may decrease as the child uses his/her vision more.

  14. “Latency” Across Ranges

  15. VISUAL NOVELTY • Children prefer familiar items over novel items. • May ignore something that is novel. • Very different from ocular impairments, in which something new will attract attention.

  16. “Visual Novelty” Across Ranges

  17. Visual Reflexive Responses • Visual Reflexive Response • Response to Visual Threat

  18. Visual Reflexive Responses

  19. MOVEMENT • Objects viewed have movement or reflective property • Way to jump-start visual system

  20. Movement • Movement may be needed to initiate and sustain visual attention, regardless of how brief. • Objects which provide the appearance of movement can be used to initiate or sustain “looking” (i.e.: toys which have shiny or reflective properties such as mylar).

  21. “Movement” Across Ranges

  22. Visual Fields Preference • Child generally shows a field dependency or preference. They have a place where there “best use of vision” is noted. • Child will typically use peripheral vision. May briefly try to use his/her central vision. • Child often appears to be “looking through” people or objects.

  23. “Visual Fields” Across Ranges

  24. Visual Motor • Visual targets need to be simple, non-complex, because it is probably too difficult at this point to use his/her vision and demonstrate a motor response (i.e.: reaching) in Phase I of resolution. • In Phase I child typically does not use a visually guided reach.

  25. “Visual Motor” Across Ranges

  26. Complexity • Remember that visual complexity not only includes what the child is looking at (visual clutter), but any form of sensory input which is occurring. • In phase I items need to be presented against a solid black background. • When working on a child’s vision in phase I the child needs a quiet environment to work and play in.

  27. COMPLEXITY • Complexity of target/object • Complexity of array • Complexity of sensory environment

  28. Complexity of Target/Object

  29. Complexity of Array

  30. Complexity of Sensory Environment

  31. “My Mother in Three Rivers Stadium” (Chris Roman)

  32. “Complexity” Across Ranges

  33. “Complexity” (cont.)

  34. DISTANCEVIEWING • Often problematic for children in early phases • In Phase I child typically only responds within 18-24 inches of his/her face. • May be result of increased complexity of visual array

  35. “Distance Viewing” Across Ranges

  36. Progression of Resolution • Early Resolution Light gazing, blink reflex • Mid Resolution color, latency, novelty, visual threat, movement • Later Resolution Field, visual motor, complexity, distance viewing

  37. Assessment Framework • Interview • Observation • Direct Evaluation/Interaction with Child

  38. CVI Range • CVI can be severe, moderate, or mild • Phases (I, II & III) describe broad functioning levels • Number ranges (0-10 scale used in assessment) describe specific levels of functioning • Phases guide intervention strategy to support best visual functioning

  39. Ranges • 0 to 10 scale 0 = no functional vision 10 = typical visual functioning • Correlation with phases is approximate Phase 1 0 to 3.5 score Phase 2 3.5 to 7.5 score Phase 3 7.5 to 10 score

  40. Interventions • “Environmental engineering” • Based on individual child/student characteristics • Support the best vision where the child is functioning NOW • Learning to use vision • Remove, decrease supports to environment as progresses through to “resolution” of CVI characteristics

  41. Phases • Phase 1 : building stable visual function • Phase 2: integrating vision with function • Phase 3: resolution of CVI characteristics

  42. Phase I • Students generally require: • Single color objects • Objects of preferred color • Objects that produce movement or are shiny • Objects presented against a simple background • Objects that are familiar -Roman-Lantzy, 2005

  43. Phase 2 • Students generally require: • Reduction of information when presented in 2 dimension • Use occluders or window cards to eliminate excess detail • Highlight or outline critical features of symbols or pictures **Students should be at least a ‘7’ on the CVI Range before asking them to discriminate 2-D objects** -Roman-Lantzy, 2005

  44. Phase 3 Students generally require: • For complexity visual field considerations in highly novel and/or over-stimulating environments -Orientation (verbal & physical) to the setting -Assistance from an adult or peer -Possible use of a cane • In the classroom help the student think about their thinking • Focus on problem solving rather than specific strategies -Roman-Lantzy, 2005

  45. CVI in Infancy • First three years are most critical for permanent changes • Early identification provides best opportunity to take advantage of brain plasticity • Don’t wait for medical diagnosis! • Parents are best reporters about their children • Expect improvements

  46. Impact of Sensory Loss on Child Development

  47. Always remember to watch for signs of stress and fatigue!! • Facial grimaces • Hand and/or finger extension, opening, and tension • Light gazing and avoiding looking at anything • Yawning and/or “falling asleep” • Hiccupping • High pitched vocalizations

  48. Contact Information • Annette Carey, Project Director (304) 558-2696, acarey@access.k12.wv.us • Ruth Ann King, Project Coordinator (304) 558-2696, raking@access.k12.wv.us Mentors • Tammy Belt Cell: (304) 646-1697, tbelt@hotmail.com • Jamie McBride Cell: (540) 533-8303, jmcbd27@hotmail.com

  49. Contact Information Continued Mentors continued: • Bridget Bailey Cell (304) 419-3187, Baboo6@aol.com • Kathy Quesenberry Cell (304) 952-1099, ques@citlink.net Partners: • Jennifer Cook Cell (304)517-8767,jfostercook@aol.com • Tina Foster Cell (304)517-4079, tfoster@access.k12.wv.us

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