Abstract of Research Article
by Erin Blanchette of Boston College
Cortical Visual Impairment is the leading cause of visual impairment in young children in the United States and in the Western World. The area of CVI research is relatively new to both researchers and doctors alike. Few studies have been done to determine the implications of environmental modifications on the visual behaviors of children with CVI.
This research study looked at the visual behaviors (localize, fixate, and track) of 3 children with CVI secondary to brain malformations Lissencephaly and Pachygyria. This study also hopes to show a possible relationship between seizures and short-range visual outcomes for students.
Dr. Christine Roman-Lantzy’s CVI Range Rating Scale, Resolution Chart, Scoring Guide, and Parent Interview Form were used to administer pre and post assessments. Modifications were made to the students’ immediate environment, which included presentation and color of materials, lighting, and level of background distractions. Data was taken on the modifications and whether or not they helped students localize, fixate, and track a stimulus for a period of 2 months.
All 3 of the children in the study improved their ability to localize, fixate, and track a stimulus for a period of time, however this was not consistent. What is important to note is that these children all demonstrated different visual abilities during pre and post-test evaluations. They all have different educational experiences and needs (1 student- 3 half-days, 1 student- 5 full days, and 1 student- 3 hrs. home-schooling per week).
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Interventions selected for students with CVI will be most effective if they are the result of careful assessment of functional vision. Interventions strategies selected should be based on the unique visual and behavioral characteristics associated with CVI (Jan & Groenveld, 1993). These characteristics include: color preference, visual field preferences, difficulties with visual novelty, attraction to movement, difficulties with visual complexity, non-purposeful gaze, attraction to light, visual latency, difficulties with distance viewing, and the inability to coordinate the visual motor action of looking while reaching (Jan & Groenveld,1993, Roman, 2004). The activities and adaptations ought to be designed to embrace any of the CVI characteristics that are interfering with the student's ability to use vision purposefully. The following suggestions highlight some guiding principles for the family and educational team in planning interventions for students who have CVI.
Suggestions for Intervention
Zip-lock freezer bags can be used on the lightbox to enhance looking behavior and to encourage visual motor progress. Consider double-bagging to avoid leakage. Only use lightbox and waterbags when lightbox is unplugged.
- Fill the bag with clear hair gel then add several drops of food coloring. The color gets mixed as the child presses on the gel surface. The color, light and movement properties will attract the child's visual attention. Begin with a single color only.
- Fill the bag with warm water and release transparent, colored beads into the water. The slightest touch will create movement without auditory competition. Again, color,light and movement properties should attract the child's visual attention. Even the slightest touch will create movement of the beads facilitating independent interaction with the materials. Begin with single color beads.
- Fill the bag with water and add drops of food coloring.
- Fill the bag with water or gel and add bright, single color (later, two colors) shapes cut from acetate sheets. Shape punches from craft stores work very well.
- Look for colored transparent objects that can be used in the zip lock bags from dollar stores. Select objects that have rounded edges. Bingo chips and small plastic balls work well.
Additional Lightbox Activities
- Transparent containers used with transparent, colored objects can be used on the lightbox for visual-motor, placing, and sorting activities. For sorting, cover the lid of the container with black paper, leaving only the shape opening uncovered. The light from the lightbox will shine through the opening creating a high contrast target for placement of the shape.
- A black grid and colored pegs (APH Product #1-08665-00) can facilitate visual motor, placement and sorting/matching activities. Remember to consider visual field function when presenting the activity and match color to the child's color preference.
- APH Familiar Object Pictures (APH #1-08666-00) are very helpful for recognition of two-dimensional information. These colored translucent pairs of pictures depict 15 common household objects that are very similar in form and color.
- APH Plexiglass Spinner and Patterns (APH #1-08664-00) can be placed on the lightbox and can be easily activated by touch and it does not have potentially distracting auditory input. Color may be added to the spinners to make them more CVI appropriate.
- Beginning puzzles can be made from black foam board and translucent color shapes (APH #1-08663-00). Start with single shape puzzles, favorite color shapes.
- Include other translucent, single color, non-auditory objects for lightbox play(Slinky©...)
Materials with reflective properties can be useful in stimulating peripheral vision and therefore, the desire to direct visual attention toward the moving target. THe following materials may be useful in motivating and individual to look.
- Any single color mylar pompom as long as the pompom matches the child's preferred color. Gold sometimes works for individuals who prefer the color yellow.
- Mylar balloons with little or no added picture or pattern. Patterns should be restricted to favorite color and should have no more than one to two colors. Balloons that are tied to a floor weight also provide an opportunity for the individual to reach/bat at the object.
- Shakers or rattles that have little or no auditory input. Sound in these objects may be acceptable if your instructional goal is for the individual to look and reach, not to continuously regard the object in hand. Dollar stores are filled with these items.
- Reflective "cuffs" can be slipped onto utensils to encourage the individual to visually attend to the spook/fork throughout mealtime. Again, match the color and/or the pattern to the individual's favorite.
- Other movement materials (non-reflective) include: color pompoms, wind socks, lava lamps, fish tanks, specially selected videos.
Two Dimensional Materials
Moving from objects to pictures requires careful planning. The following suggestions provide a framework for this progression.
- match familiar objects to same pictures and present in pairs.
- Simple color, translucent pictures, like the APH Familiar Object Pictures (APH #1-08666-00), presented on the lightbox can teach picture discrimination, picture recognition, and picture identification.
- Create simple picture books with only one picture per double page presented. Images should be selected based on color preference, familiarity of subject, and simplicity.
- Create or select books that have pictures based on a theme, for example, "foods I eat", "things I wear", "toys I like". Avoid pictures with internal detail and do not use photographs.
- Commercial books that are very simple are available. Maizie books, Bugs in a Box books are two examples.
- When photographs are presented, begin with faces, and only later present pictures of familiar people against backgrounds.
- Additional photo books can be designed with themes in mind, for example, photos of balls, or, photos of shoes...
- Recognition of self in photographs generally occurs around the same time that an individual is able to recognize themselves in a mirror image.