Cortical Visual Impairment

1. Cortical Visual Impairment CVI

2. The current leading cause of visual impairment among children is not a disease or condition of the eyes, but cortical visual impairment (CVI)—also known as cerebral visual impairment—in which visual dysfunction is caused by damage or injury to the brain.

3. Medical definition Cortical visual impairment (CVI) may be defined as bilaterally diminished visual acuity caused by damage to the occipital lobes and or to the geniculostriate visual pathway. CVI is almost invariably associated with an inefficient, disturbed visual sense because of the widespread brain damage.

4. Educational definition Cortical visual impairment (CVI) is a neurological disorder, which results in unique visual responses to people, educational materials, and to the environment. When students with these visual/behavioral characteristics are shown to have loss of acuity or judged by their performance to be visually impaired, they are considered to have CVI.

5. During the last several decades, our understanding of vision has markedly improved. It is now realized that vision is not a single sense but a combination of complex senses, involving most of the brain in its process. In different locations of the brain, there are specialized areas for distance vision, recognition of faces, objects, colors, contrast, and movement.

6. Cause CVI is caused by widespread damage to the brain, which affects most of the specialized visual centers, resulting in a damaged, inefficient visual sense.

7. The medical definition of CVI is not well understood by non-medical professionals. While acuity testing is difficult in the young and disabled for physicians, it is even more difficult for teachers. Also, there are many children with visual problems similar to CVI, except they have normal acuity. This visual condition is called "cortical visual dysfunction" (CVD). The educational management of children with CVI and CVD is similar.

8. CVI is suspected by: a normal or close to normal eye examination; a medical history which includes neurological problems; and the presence of unique visual/behavioral characteristics.

9. Unique visual/behavioral characteristics • Normal or minimally abnormal eye exam. • CVI may co-exist with optic nerve atrophy, hypoplasia or dysplasia and ROP. • Difficulty with visual novelty. • Prefers to look at old objects, not new, and lacks visual curiosity. • Visually attends in near space only. • Difficulty with visual complexity/crowding. • Performs best when one sensory input is presented at a time, when the surrounding environment lacks clutter, and the object being presented is simple. • Non-purposeful gaze and/or light gazing behaviors. • Distinct color preference. • Preferences are predominantly red and yellow, but could be any color.

10. Visual field deficits. • Not so much the severity of the field loss, but where the field loss is located. • Visual latency. • Visual responses are slow; often delayed. • Attraction to movement, especially rapid movement. • Absent or atypical visual reflexive responses. • Fails to blink at threatening motions. • Atypical visual motor behaviors. • Look and touch occur as separate functions, e.g., child looks, turns head away from item, then reaches for it. • Inefficient, highly variable vision.

11. Strategies • Slow down.  • Allow time for student to respond. • Simplify the task. • Schedule visual experiences for the time of day when the student demonstrates optimal visual functioning.

12.  5. Be specific about what you want the student to see and to do. 6. Sequence the task. 7. Provide structure and sameness in each presentation.

13. Environment Provide an environment that is free from visual clutter. Be sure that the work surface does not have a pattern.  Be sure that the learning environment has only essential visual information, especially on background surfaces and spaces.

14. Materials  Enhance the visual targets. Keep visual information simple, constant, and predictable. Use real objects in natural sequences to aid in the understanding of the real visual environment.

15. To summarize: CORTICAL VISUAL IMPAIRMENT Cortical Visual Impairment (CVI) is a temporary or permanent visual impairment caused by the disturbance of the posterior visual pathways and/or the occipital lobes of the brain. The degree of vision impairment can range from severe visual impairment to total blindness. The degree of neurological damage and visual impairment depends upon the time of onset, as well as the location and intensity of the insult. It is a condition that indicates that the visual systems of the brain do not consistently understand or interpret what the eyes see. The presence of CVI is not an indicator of the child's cognitive ability.

16. What all should be in a CVI/Functional Vision Evaluation Kit? September 1, 2008 — Created by Diane Sheline, CTVI, CLVT, dianesheline@yahoo.com    updated 09/18/2008 CVI FUNCTIONAL VISION EVALUATION KIT•    Penlight/flashlight with different colored caps/filters•    Flashlight with different colored filters•    Mylar Pompoms…preferably red and yellow•    Cereal and other real or simulated food items…Fruit Loops, red licorice, banana, Cake Decors and Cheerios •    Mylar paper or wrapping paper…preferably red and yellow •    Soap bubbles, for blowing•    Measuring tape•    Slinky…solid colors and plastic •    Hidden pictures or I Spy book•    Variety of different colored balls in a variety of sizes•    A black, light-absorbing background…2 yards of black fabric, Invisiboard, or other similar material/board •    2 yards of white fabric•    Variety of flashing lights…including bikers safety light, snap-on-spoke light clips, etc. •    Supplementary light…such as a clamp on directional light •    Variety of yellow and red toys… such as Elmo, Big Bird, reflective mirror, balls, etc., or “sets of red and/or yellow objects to be sorted into same colored containers •    Black and white toys•    Mirrors

17. MORE MATERIALS: •  Reflective materials – mylar balloons, pom poms, shakers, etc. • Suspended or moving objects (windsock, ball on elastic cord, etc. • Slap bracelets in reflective red and yellow • Blinking “ice cubes” attached to elastic “ring” band…or any blinking lights that can be thoroughly cleaned/washed • Personal “Laser Light Show” fan • Spinning Pinwheel on long stick (yellow or red • Variety of sunglasses…BabyBanz, yellow clip-ons, overglasses sunglasses, etc. • Croakies…adjustable straps to hold glasses in place • Visors or brimmed caps • Items from everyday routines in solid colors…cups, spoons, toothbrushes, etc. • Container of Lysol wipes • Notebook of variety of CVI articles for parents • Rolling suitcase to hold it all in • Extension cord(s) • Extra Batteries (AA and AAA) • Selected equipment and materials from APH including;o    Regular or Mini Light Box with clear and colored overlays and colored acrylic objectso    ToAD: Tools for Assessment and Development of Visual Skillso    Invisiboardo    ISAVE Visual Field/Acuity Grido    Sensory Learning Kit • Make sure to have the parent bring in the child’s favorite toyCreated by Diane Sheline, CTVI, CLVT, dianesheline@yahoo.com    updated 09/18/2008

18. What will cause the use of the vision? “rut” in the snow

19. http://www.aph.org/cvi/advo.html http://www.aph.org/cvi/index.html http://dianesheline.wordpress.com/toolbox/techniques-and-strategies-to-use-with-students-with-cortical-visual-impairment/