Cortical Visual Impairment

1. Cortical Visual Impairment Sandy Newcomb, PhD Connections Beyond Sight and Sound University of Maryland

2. Based on work of: Roman-Lantzy, Christine. (2007). Cortical visual impairment: An approach to assessment and intervention. New York: AFB Press.

3. Overview of presentation • Introduction to CVI • Characteristics of children with CVI • Assessment - functional vision assessment

4. What is Cortical Visual Impairment? • Vision loss due to damage or malformation in the brain that interferes with the child’s ability to understand vision information coming from the eyes • Leading cause of VI in young children

5. CVI is suspected when: • Normal eye exam or eye condition cannot explain level of visual impairment • History of brain injury or malformation • Presence of unique visual characteristics

6. Medical history significant for CVI • Asphyxia/Hypoxic-ischemic encephalopathy (HIE) • CVA/stroke • Intraventricular hemorrhage (IVH) • Periventricular leukomalacia (PVL) • Infection • Structural anomalies • Trauma • Prematurity • Metabolic disorders

7. Color Movement Latency Visual fields Complexity - array, sensory environment, object Light gazing Distance Reflexes Novelty Visual motor Unique visual characteristics

8. Severity of CVI • Children with CVI can function from almost no vision to almost typical vision • The 10 characteristics interfere with visual functioning to varying degrees depending on the severity of CVI

9. COLOR • Color vision is usually preserved in children with CVI • Children often have a favorite color or will only look at certain colors • Children with typical vision or ocular problems will look at any color

10. MOVEMENT • Movement attracts visual attention • Children with CVI may only look at something that moves or has movement quality (shiny) • Often helps children with CVI with mobility

11. Latency • Latency is the length of time between when a visual stimulus is presented and when a child looks at or orients towards the stimulus

12. Visual fields • Children often have field losses or field preferences

13. COMPLEXITY

14. Light gazingnon-purposeful gaze • 60 % of children with CVI often compulsively gaze at lights • Most have periods of non-purposeful gaze when they are not looking at anything in particular

15. Distance viewing • Children with CVI can often only look at things close to them • Distance is a function of complexity

16. Visual reflexes • Reflexes often absent, or inconsistent • Blink to touch between eye brows • Blink to threat

17. Visual novelty • Children with CVI often look at familiar things better than novel • Novel environments can be challenging • Familiarity is easier because CVI is about learning. The child has learned to look at what is familiar.

18. Visual motor • Children with CVI often have trouble using eyes and hands together • Often look, look away and reach • Some children cannot look at what they are holding • Some children need to touch something to look at it

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

20. Severity of CVI • CVI can be severe, moderate, or mild • Severity of CVI is described in three phases

21. Major goal of each phase • Phase 1 : building stable visual function • Phase 2: integrating vision with function • Phase 3: visual curiosity, visual learning