Guiding Principles for Orientation and Mobility Instruction with Students Who Have Cortical Visual Impairment Presented by MDE-LIO Cortical Visual Impairment.

Guiding Principles for Orientation and Mobility Instruction with Students Who

Have Cortical Visual Impairment

Presented by

MDE-LIO

Cortical Visual Impairment Team

April 24, 2015

Characteristics of CVI• Color Preference

• Need for Movement

• Visual Latency

• Visual Field Preferences

• Difficulties with Visual Complexity

• Light-Gazing and Nonpurposeful Gaze

• Difficulty with Distance Viewing

• Atypical Visual Reflexes

• Difficulty with Visual Novelty

• Absence of Visually Guided Reach

(Roman-Lantzy, 2007)

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Color Preference

Red or yellow most common but any color could be a favorite.

Color “anchors” visual attention.

Color may help sustain visual attention.

O&M Examples:

• Wear the student’s preferred color.

• An Exit sign is backlit and the lettering is red.

• The student’s locker, marked with his/her preferred color, will

assist with locker identification.

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Need for Movement

Students with CVI are attracted to targets that have the physical properties of movement or have shinny or reflective surfaces.

O&M Examples:

• Use shinny moving target on chair or door knob so student can orient to it, or use as a directional cue.

• COMS can use movement features of environment to facilitate orientation or even mobility.

• Student may see a moving car but not a parked car.

• Movement can also be a source of distraction and a danger.

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Visual Latency

Refers to a delay between the time a target is presented and the time the student visually responds to it. The delay can be seconds, or in some cases, minutes long. You may observe the student glance at the target, fixate on the target, quiet, or smile.

Students must be provided “wait time” or they may appear inattentive.

Providing targets that are of the preferred color, moving, in the preferred visual field, against a simple background, at near, and familiar, may reduce visual latency.

O&M Examples:

• Hold the target in the same position until it hurts!

• Allow student to handle items.

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Visual Field Preferences

There is generally a preference for using the peripheral fields over the central fields.

Lower field losses are the most common and last to resolve.

O&M Examples:

• Due to problems with visual fields, a student may demonstrate safety concerns as they move through their environment. They may not perceive drop offs, unexpected obstacles, or moving targets.

• The use of the long cane or an adaptive mobility device (AMD) may be required.

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Difficulties with Visual Complexity

When objects or symbols are presented with competing objects, symbols, or even sensory information, the individual may have difficulty locating the target.

There are three ways complexity may interfere with visual functioning.

1. Complexity of the Target

2. Complexity of the Visual Array

3. Complexity of the Sensory Environment

O&M Examples:

• Familiarize a student to a new school/classroom prior to beginning of new school year and before a teacher begins decorating.

• Preview targets along route using pictures taken on an iPad, cell phone camera.

• Use a telescope or binoculars to reduce visual complexity.

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Light Gazing and Nonpurposeful Gaze

Students may be attentive to lights and demonstrate difficulty attending to other visual targets.

O&M Examples:

• Light may be a distractor, may need to avoid window light, reflection of water.

• A baseball cap may occlude overhead lights when worn on lessons.

• Students may require the use of an AMD if light gazing interferes with travel.

• Light may be used to motivate student’s mobility.

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Difficulty with Distance Viewing

When viewing at distance, student may demonstrate difficulties due to the complexity of the environment. Reducing the distance between the student and the target can reduce complexity by “filling” the visual field. This reduces the amount of information the student has to sort, making the target the most visually accessible.

O&M Examples:

• Present distance information at near for initial instruction and repeat over numerous sessions.

• Evaluate distance vision often as the complexity of the environment will impact on student’s ability to visually detect targets.

• Pair other characteristics of CVI with target, such as movement.

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Atypical Visual Reflexes

Two visual reflexes that may be atypical in students who have CVI even with a normal eye exam:

1. Visual blink reflex

2. Visual threat reflex

O&M Implications –

• Student may not be able to protect themselves from objects moving quickly towards their face, i.e. a ball, a swing.

Two visual reflexes that may be atypical in students who have CVI even with a normal eye exam:

Visual blink reflex

Visual threat reflex

• O&M Implications –

• Student may not be able to protect themselves from objects moving quickly towards their face, i.e. a ball, a swing.

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Difficulty with Visual Novelty

Students with CVI generally have a counterintuitive response to visual novelty. Objects preferred are those that are familiar and meet the other characteristics of CVI, i.e. preferred color, reduced complexity, and movement.

O&M Examples:

• Select landmarks that are familiar or that share characteristics of CVI, i.e., color, complexity.

• Routes will need to be repeated numerous times, beginning in home/school setting and gradually moving into the community.

• It is critical to assess students with CVI in unfamiliar areas.

• A student who has difficulty with visual novelty may experience a great deal of difficulty traveling in an unfamiliar area and may require supervision for greater lengths of time.

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Absence of Visually Guided Reach

Refers to the specific “look, look away” reach pattern associated with students who have CVI.

O&M Examples:

• Student may visually locate a target, but look away as their hand moves in the direction of the target.

• Allow time for tactile exploration.

• Match your voice to the target.

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Suggestions

1. Complete the CVI Range Assessment with another member of the team. Place results on the CVI Orientation and Mobility Resolution Chart. Interventions may move forward and backward from where student is visually functioning.

2. Utilize additional assessments to obtain skill level.

3. Plan lessons using the same scope and sequence you would utilize for a student with an ocular impairment. Incorporate the 10 characteristics of CVI per the needs of the student. The CVI Orientation and Mobility Resolution Chart will assist you in your planning.

4. Repeat lessons numerous times to build familiarity of the visual materials and familiarity of the route.

5. Provide intermittent breaks during lessons. It will be more challenging for the student to combine both visual and physical tasks.

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Suggestions Continued

6. Begin lessons with a “visual warm-up”.

7. When marking landmarks with student’s preferred color, movement, etc., be sure to use landmarks that are permanent/naturally occurring, and the student can learn to recognize, i.e. a water fountain, a turn, a room number.

8. Simple to complex. Familiar to unfamiliar.

9. Cane or pre-cane device may need to be considered.

10. Consistency is important! Communicate with other team members and family regularly.

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Community Based Instruction

1. Begin with small, simple trips.

2. Due to difficulties with distance vision, may need to utilize “human guide” techniques to navigate surface level changes, ascending/descending stairs.

3. Keep verbal descriptions simple. Pause and provide time for student to respond.

4. Practice activity/route numerous times over several sessions.

5. Use pictures (simple) of visual targets that are associated with task to assist with identification, and building familiarity.

6. Use the adaptive mobility device or long cane for certain aspects of the route.

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References:

Pogrund, Rona (et al.).(2012).Teaching age-appropriate purposeful skills: an orientation and mobility curriculum for students with a visual impairment (TAPS), 3rd edition. Austin, TX. (pp. 45-54)

Roman-Lantzy, C. A. (2007). Cortical Visual Impairment, An Approach to Assessment and Intervention. New York: AFB Press.

Santamoor, Gregory. Teaching Purposeful Mobility Skills to Students with Cortical Visual Impairments. PowerPoint Presentation, May 29, 2012.

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References continued.

Wiener, W. R. , Welsh, R. L., and Blasch, B. B. (Eds.). (2010). Foundations of Orientation and Mobility, Third Edition: Volume 2, Instructional Strategies and Practical Applications. New York: AFB Press. (pp. 667-711).

West Virginia Department of Education, CVI and O&M (online video) Presented by Christine Roman. http://wvde.state.wv.us/player.php?m=m4&vid=osp/cvi/orientation-and-mobility

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Presenters:

Cynthia Barker, [email protected]

Susan Bradley, [email protected]

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