CORTICAL VISUAL IMPAIRMENT-WHAT WE LEARNED AT THE …



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Texas School for the Blind

& Visually Impaired

Outreach Program

tsbvi.edu

512-454-8631

Superintendent William Daugherty

Outreach Director Cyral Miller

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O&M For Students with CVI (Cortical Visual Impairment)

Date: February 3,2010

Time: 1:30-3:30 PM

Location: TETN Network Broadcast #35070

Presented by

Ruth Ann Marsh, O&M Consultant, TSBVI Outreach

ruthannmarsh@tsbvi.edu

Lisa Calaci, O&M Instructor, TSBVI

lisacalaci@tsbvi.edu

Lynne McAlister, Lead Teacher, TSBVI

lynnemcalister@tsbvi.edu

Developed by

Texas School for the Blind & Visually Impaired

Outreach Program

O&M for Students with CVI

Lisa Calaci, COMS® @ TSBVI

Ruth Ann Marsh, COMS®, Consultant, TSBVI Outreach Programs

Lynne McAlister, TSBVI lead teacher

Cortical (Cerebral) Visual Impairment

(AKA Neurological Visual Impairment)

CVI is a “neurological disorder resulting from brain damage, which results in abnormal or unique visual responses to people, objects and the environment.” (Shaman, 2009)

The visual impairment is not due to damage to the eye itself but to the visual pathway, i.e. optic nerve and/or the parts of the brain that process and interpret the visual information received from the eyes – visual cortex, parietal lobe and temporal lobe.

The Human Brain

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Figure 1 Image of the human brain.

The Plasticity of the Brain

40-80% of brain is involved with visual processing.

Research suggests that the brain can rewire itself to dedicate itself to different functions.

How are children with CVI identified?

CVI is not a purely medical diagnosis but rather the presence of a pattern of visual characteristics paired with a medical diagnosis of brain damage.

An impairment of the eye itself is not the cause of these visual characteristics, although CVI can occur in conjunction with an impairment to the eyes.

Prevalence of CVI

CVI is often under diagnosed.

CVI was not recognized as a cause of visual impairment until the mid 1980s.

CVI is the fastest growing cause of visual impairment in developed countries, possibly because more children with brain damage are surviving the trauma and living longer.

Problems with Medical Diagnosis

Eye report frequently doesn’t list CVI

MRI’s may be normal

Eye exam may be normal

CVI may be occur with the presence of other eye conditions, such as glaucoma

Look for ‘red flags’

Causes of CVI - Red Flags

(This is not an all inclusive list.)

Asphyxia (drowning, SIDS, choking, birth trauma)

Stroke

Periventricular Leukomalacia (PVL)

Cranial infection (TORCH, toxoplasmosis, rubella, cytomegalovirus virus, herpes/HIV, meningitis)

Brain tumor

Traumatic Brain Injury (TBI)

Brain hemorrhage

Visual Characteristics Indicative of CVI

Color Preference:

The visual response to one color may be noticeably present. The preferred color is often red or yellow, but other color preferences are possible. Color acts as a visual magnet or anchor.

Attraction to Movement:

Movement of either the item to be viewed or movement of self in order to see an item helps activate the visual response. Reflective items have movement characteristics

Visual Field Preferences:

Especially to the periphery where movement may be noted.

Visual Latency:

A delay in the time a target object is presented and the time when it is first seen. The delay is two-fold:

1. delay in directing vision towards the target, and

2. delay in correctly identifying the target item.

Visual Motor:

Look and touch may happen as two separate events. This may occur because of a miscommunication between two different areas of the brain:

1. The temporal lobe perceives & sees/interprets the object, and

2. The parietal lobe instructs the body to act on the object.

Visual Complexities:

Too many objects in the visual field cause overload which may lead to visual shut-down or

May create difficulties with distant viewing.

May occur:

Within the object itself (faces, busy patterns, many features/colors)

As a result of what is behind the object (referred to as ‘array’). May particularly have an adverse effect on distant viewing.

Visual Novelty:

Fluctuations in vision may be perceived. Reasons for differences in visual use may be:

Systemic: due to fatigue.

Environmental: Novel items are less easily seen. Complexity of item or visual array may be a factor

Visual Reflexive Responses, i.e. the absence of or delayed response to:

Blink to threat

Blink to touch

Non-Purposeful Gaze:

Seems to be looking through you.

Abnormal responses to light:

Light Gazing: staring at light sources for extended periods of time.

Photophobia: sensitivity to light (eye responds correctly to light but the brain reacts abnormally to light)

Difficulty with attending to more than one sensory channel at a time, (i.e. complexity of environment)

Looking, listening and tactile exploration may need to occur separately in order for processing of information to occur.

What is the vision world of a person with CVI like?

Imagine:

Looking for one person in a crowded sports stadium

Looking at a piece of modern art with lots of shapes and colors but no understanding of what the artist was trying to represent

Looking at a partially finished jigsaw puzzle but not having the picture of what it is supposed to look like.

What is this?

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Figure 2 Image of an optical illusion black and white photo of a cow

INTERVENTION

It is important to remember that resolving CVI does not follow the accepted methods of teaching. Instead of focusing on the next step of vision resolution, you should find out where the student is currently functioning, and with repeated opportunities for them to use their vision,

… the brain forms new pathways and the student himself achieves the next level of resolution.

Need for constant on-going assessment.

Three Important Educational Beliefs Re: CVI

1. Children with CVI have the capacity to see more effectively and become more active and fulfilled participants in their school environments. (For O&M instruction, add “home and community”.)

2. Improved vision and school participation is dependent on a carefully designed educational program consisting of enjoyable and simplified activities embedded in familiar routines and specific to each child’s unique visual and learning needs.

3. Effective learning requires that well trained team members work collaboratively in order to improve vision and learning for children with CVI. (Adapted from Edelman, et al, 2006)

•4. An Additional Educational Factor to Consider and Remember

The presence of CVI does NOT always mean that a cognitive impairment is present.

Just as an eye-based vision loss can affect the rate of learning, CVI often slows down the rate of learning.

But the potential for learning may not be adversely affected and cannot be predetermined.

The Resolution Factor/Impact

The presence of CVI is a dynamic condition, i.e. that the degree to which the CVI characteristics occur can (and usually does) change over time.

Use of vision and information gathered visually can increase over time.

Interventions can be designed to increase the use of vision as well as the interpretation of visual information.

The role of VI professionals is to organize experiences to help the child with CVI increase visual ability and make sense of his/her vision.

The Resolution Process

Can be charted using Christine Roman-Lantzy’s CVI Resolution Chart, which has ten ranges that are grouped under three phases.

The charting is done by the IFSP/IEP team, is usually led by the TVI and should include input from the O&M specialist.

Suggestions for O&M Instruction: General

Approach the child’s education with a holistic and functional perspective, and as a member of a team that has a common goal – fostering the development of the child’s vision and the ability to use it successfully in a variety of environments.

Ask a TVI to participate in the Functional Vision Evaluation and LMA of a student with CVI and the completion of a Resolution Chart in order to learn more about CVI and how changes occur.

Read pages 142-146 in Cortical Visual Impairment: An Approach to Assessment and Intervention by Christine Roman-Lantzky and become familiar with the O&M Resolution Chart. (See handout.)

The heightened importance of old standby considerations:

Realize that the mantra of VI professionals --that each child is an individual with unique needs and skills -- is even more applicable for students with CVI.

Extended WAIT TIME is critical to allow for processing visual information.

Bring the world to the child;

Bring the child to the world.

Consider each of the CVI Characteristics and how they might impact O&M instruction.

Color Preference

Wear the student’s favorite color. A smock or vest may be an easy way to do this.

Mark key locations with the student’s favorite color. Ex.- a colored frame around a wall sign may draw his/her attention to it.

AmbuTech has red and orange ball and roller tips. The colored tips may motivate the student to use a cane and promote attention to the path ahead.

Use tape in a student’s favorite color to mark the placement of hands (or the lower bar) on a pre-cane device.)

Point out the red lines to either side of the aisles in Target and Walmart stores. The overhead signs designating departments are also often in red.

Incorporate preferred color when making maps for the student’s use.

Attraction to Movement:

Mark key points on a route with helium filled balloons (in the student’s favorite color) tied to a weight.

Use Mylar pompoms to mark key destinations such as a student’s chair.

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Figure 4 The top of a desk chair wrapped in Mylar pompom tinsel

Use hand motions to direct a student’s attention or provide a directional cue.

Visual Complexity

Avoid wearing overly busy clothes.

Expect that a student will have difficulty recognizing faces. Provide verbal prompts in social settings so that he/she is not embarrassed. Provide opportunities to practice recognizing faces by using photos of key people seen regularly.

Spend ample time familiarizing a CVI student to a new classroom/school prior to the beginning of the school year and before the teachers begin decorating. Schedule at least one lesson after the teachers have returned and provide ample practice the first few days of the school year after students return.

Try to limit visual complexity when choosing a training site, especially when teaching a new skill.

Use of a telescope, binoculars, digital camera or cell phone may help control for visual clutter (as well as be a motivator).

The use of a cane or pre-cane device may help the student focus on what is ahead which also helps cut down on visual clutter by decreasing the array. Additionally, the movement of a cane may attract the student with CVI and promote use of vision, but distract him/her from awareness of other key visual information such as changes in elevation.

Visual & Environmental Complexity

Because children with CVI have difficulty attending to more than one source of sensory input at a time, try to limit auditory prompts, as they tend to interfere with vision.

Use physical prompts, especially those that involve movement.

Visual Novelty

Use a sequence of photos with increasing complexity to introduce/familiarize a student to a new landmark. (Also visual complexity)

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Figure 5-8 Series of photos showing restaurant sign from far-, mid-, and near-distance

Give the student pictures of desired items when teaching shopping or of a landmark on a new route.

When introducing a new route, make a picture book with the student of key points on the route. Use the preferred color for the background. Keep it visually simple so put only one picture to a double page. Use the picture book to review a route before practicing it again.

On any new route, allow time for exploration, perhaps while traveling with a guide, so that the student can become familiar with the new surroundings and you can point out key areas.

Expect the student’s cane skills to temporarily decline when working in a new area until the environment becomes more familiar.

Provide repetition, repetition, repetition until the student seems comfortable in a new environment or route.

Introduce new cane skills in a familiar environment to help avoid visual distractions.

Generalizing from one environment to another may be very difficult for some students with CVI.

Watch for evidence of visual and/or physical fatigue. When this occurs, the student is not capable of using his/her vision efficiently. Possible options are to provide a rest period, return to a more familiar setting/topic or discontinue the lesson. (Also part of Visual Complexity)

Visual Motor

Because of the ‘look, look away, touch’ sequence, allow time for tactile exploration of items in order to promote concept development. As vision resolves, the tactile and visual exploration will occur more simultaneously, but only when the child is ready.

Visual Latency

Another reason to increase wait time – to allow for the delay between first seeing and then acting upon a visual target.

Moving a target item may decrease the delay.

Allowing physical handling may facilitate

The identification process.

Visual Field Preferences

Know the student’s visual field preferences.

Use movement in the preferred visual fields to draw the student’s vision to a desired object or provide a visual prompt.

Repeated use of the preferred visual fields can promote expansion of vision by slowly moving items into less preferred fields.

Lighting considerations:

While photophobia is common, it is not the classic photophobia.

Be aware that the presence of shadows creates complexity. Teach the student how to recognize shadows and what causes shadows to change. Or avoid times of day when shadows are present.

Be aware that reflections from windows, standing water or shiny surfaces may be distracting and may be the cause of changes in performance.

Attraction to reflective surfaces can be utilized to mark a landmark or promote visual field expansion. (Ex.- Mylar pompoms)

Environments with ceiling fans may be very distracting as the fans can make the lights flicker – creating both movement and light distortions.

Visual reflexive response

Consider having the student wear protective lenses when traveling outdoors because of the lack of blink response.

Think of these suggestions as a menu from which you can choose – ideas to try but not a prescription. They are offered as part of a dynamic document, to which I hope people will regularly add, so that the ideas to choose from become many and varied – just as our students with CVI are a varied group of individuals with unique needs and abilities.

Send your ideas for instructional strategies for the student with CVI to RuthAnnMarsh@tsbvi.edu.

Excerpts from: Cortical Visual Impairment: An Approach to Assessment and Intervention, by Christine Roman-Lantzy, AFB Press, 2007, pages 142-146

CONSIDERATIONS FOR ORIENTATION AND MOBILITY

All children who have a visual impairment, including those with CVI, need to be evaluated for their requirements for orientation and mobility instruction by a certified O&M specialist. This principle holds true whether the child is able to ambulate independently or is learning to operate a power wheelchair. However, as with other aspects of the behavior of students with CVI, their behavior when moving around is open to misinterpretation, as illustrated in following case study.

Charles is an 8-year old student who spends half of his school day in a typical third-grade class and half in a special education class. Charles has CVI associated with a rare syndrome. He is ambulatory but moves throughout the school using a random, inefficient pattern; he prefers to touch the arm or back of another student rather than walk independently. Charles is especially tentative on staircases and on occasion, he has stumbled and has even fallen down several steps. In the classroom Charles tends to have trouble staying seated. He avoids seat-work and is frequently moving away from his desk to other areas in the classroom. Charles appears to be fascinated by the decorations suspended from the ceiling. The school psychologist has talked to Charles’ parents about possible attention deficit disorder (ADD).

This scenario represents one example of how the behavior of students with CVI may be misinterpreted. The difficulties Charles displays with moving independently may be a result of the CVI-related characteristics of difficulty with complexity in the environments, visual field preferences, and difficulty with distance viewing. His apparent inattentiveness in the classroom may be attributable to difficulty he may be experiencing with complexity, a tendency toward light-gazing, or an attraction to movement. Until Charles is carefully evaluated, it is impossible to know whether his behavior is being influenced by the presence of CVI or whether he has attention-related problems for some other reason. But, no matter what the cause, Charles is mot moving efficiently and may not be safe in his school environment.

The CVI Range can be used by O&M specialists to determine the extent to which CVI-related characteristics are affecting a student. Results of the assessment can then be plotted on a CVI Resolution Chart that specifically focuses on considerations for O&M.

The CVI Orientation and Mobility Resolution Chart (see figure 6.5) is constructed in accordance with the same principles as the CVI Resolution Chart. The chart integrates information about CVI-related characteristics, the degree of effect of the characteristics, the CVI phase, and the level of environmental adaptations in a single document. Unlike the CVI Range Across- and Within- CVI Characteristics assessment forms, which are used to evaluate the presence of CVI, this form is used to track and monitor progress and to support daily program planning. The O&M Resolution Chart uses information obtained from the CVI Range, but specifically interpreted for use by an O&M instructor: implications of the presence of CVI for safe and independent travel are the focus of the form.

Marking the O&M Resolution Chart involves the same procedures used with the CVI Resolution Chart:

Mark an X through boxes that represent resolved visual behaviors.

Highlight boxes that represent current visual behaviors.

Mark an O inside boxes describing visual behavior that may never resolve because of co-existing ocular conditions.

CVI Resolution Chart

Figure 6.5 CVI O&M Resolution Chart

From Cortical Visual Impairment: An Approach to Assessment and Intervention, by Christine Roman-Lantzy, copyright © 2007, AFB Press, New York. All rights reserved. This page may be reproduced for educational use only.

|Phase I: |Phase II: |Phase III: |

|Building Visual Behavior |Integrating Vision with Function |Resolution of CVI Characteristics |

|Level I Environmental Considerations |Level II Environmental Considerations |Level II Environmental Considerations |

|CVI Characteristics |Range 1-2 (0) |Range 3-4 (.25) |Range 5-6 (.50) |Range 7-8 (.75) |Range 9-10 (1) |

|Color Preferences |Single color environmental |Strong single-color preference |Objects or environmental features |More colors and high-contrast |Safe travel is not dependent on |

| |features may be attended to in |persists |that have 2-3 colors may now be |areas may elicit visual attention|color cues |

| |near space | |attended to within 4-6 feet | | |

|Need for movement |Targets viewed have movement |Movement in the environment may |Movement may be needed to |Movement not required for |Movement is not necessary for |

| |and/or reflective properties |distract from primary target |establish attention on target / |attention within 3-4 feet; may be|near or distant visual attention |

| |May be attentive to ceiling fans | |destination |necessary beyond | |

|Visual latency |Prolonged Periods of visual |Latency slightly decreases after |Latency present only when student |Latency rarely present |Latency resolved |

| |latency |periods of consistent viewing |is tired, stressed or | | |

| | | |over-stimulated | | |

|Visual field preferences |Distinct field preferences; may |May be able to use both right and|Visual field preferences persist |Increasing use of right and left |Visual fields unrestricted |

| |use one eye for peripheral |left peripheral fields but will | |fields nor near and distance | |

| |vision, the other eye for central|continue to show strong | |activities | |

| |vision |preference for original | | | |

| | |peripheral field | | | |

|Difficulties with visual complexity |Visually attends only in strictly|Visually attends to or fixates on|May be able to tolerate low level |Competing auditory stimuli |Only the most complex |

| |controlled environments---those |simple targets at near (within 3 |of familiar background noise while|tolerated during periods of |environments affect independent |

| |without sensory distractions |feet), with environment |maintaining visual attention on |viewing |travel |

| |Engages in rote, assisted travel |controlled for sensory |familiar targets |May travel familiar routes using |Environmental or traffic signs |

| | |distracters |Engages in rote or route travel |naturally occurring, simple |may now be useful of independent |

| | | |with adapted visual canes |landmarks or cues |travel |

|Light-gazing and non-purposeful gaze |Is overly attentive to lights |Is less attracted to lights; can |Light is no longer a distracter | | |

| |Room light may have to be reduced|be redirected to other targets | | | |

|Difficulty with distance viewing |Visually attends in near space |Occasional visual attention to |Visual attention extends beyond |Visual attention extends to 10 |Visual attention extends beyond |

| |only |familiar, moving, or large |near space, up to 4-6 feet |feet with targets that produce |20 feet |

| | |targets in simple or familiar |Complexity in the environment may |movement |Demonstrates memory of routes, |

| | |settings up to 3 to 4 feet |reduce this distance |Color cues, movement, and size of|cues, or landmarks and may not be|

| | | | |target may be factors in visual |able to travel independently |

| | | | |attention | |

|Atypical visual reflexes |No blink in response to touch |Blinks in response to touch, but |Blink response to touch |Blink response to visual threat | |

| |and/or visual threat |response may be latent |consistently present |consistently present | |

| | | |Visual threat response |May now anticipate approaching | |

| | | |intermittently present |obstacles | |

|Difficulty with visual novelty |Responds only to familiar objects|May visually attend to objects or|Visually attends to landmarks or |Selection of objects or |Selection of objects, |

| | |environmental features if they |cures that are highlighted with |environmental or route cues |environments not restricted or |

| | |share characteristics with the |familiar color or pattern |remembered after several sessions|specially adapted |

| | |familiar objects | |of familiarization | |

|Absence of visually guided reach |Reach, touch, and look occur as |Occasional visually guided reach,|Visually guided reach is used with|Look and reach occur in sequence,|Look and reach occur as a single |

| |separate functions |possibly with a single, preferred|familiar materials, simple |but not always together |action |

| | |object |configurations, and “favorite” | | |

| | | |color | | |

Key:

• Draw an X though boxes that represent resolved visual behaviors

• Use highlighter to outline boxes describing current visual functioning

• Draw an O in boxes describing visual skills that may never resolve because of coexisting ocular conditions.

In planning O&M instruction for students who have CVI, as with any other interventions, a number of guiding principles should be followed. (See color insert Photo 24a-c.) The environmental adaptations and specialized instruction should be designed in consideration of the identified CVI characteristics demonstrated by the student. In addition, the intervention is not a stand-alone intervention; it is an approach or overlay used in conjunction with the best practices in O&M instruction. That is, the CVI interventions should be adaptations to activities designed to teach orientation in space or safe, efficient travel. For example, if a map is being used to facilitate orientation skills, the instructors should consider adapting the map to include the student’s preferred color and lower levels of visual complexity.

CVI adaptations need to be paired with naturally occurring landmarks or cues. For example, if a student who is learning to visually identify his or her own classroom while traveling in the hallway displays the CVI characteristics of color preference (yellow), a need for movement to stimulate visual attention, and difficulty with complexity, the O&M instructor may place a yellow, reflective target on the water fountain next to the entrance to the classroom. The water fountain in a permanent landmark that will continue to exist in the same location even after the CVI adaptation is no longer necessary. If the same yellow indicator were to be placed on the wall, it might be far more difficult for the student to learn the distinct environmental feature that will help him or her identify the specific destination independently. (See color insert Photo 25.)

Even when many of the characteristics associated with CVI have become resolved, a student may not be able to travel safely in unfamiliar, highly novel, or complex environments. The characteristics of difficulty with distance viewing, visual field preferences, and difficulties with complexity generally continue to have an effect on the individual into Phase III. At this point, the student may be independent in a variety of activities that require vision and it is likely that the remaining effects of CVI will be subtle and not easily recognized. The O&M instructor has a responsibility to continue to provide instruction and to educate others regarding the student’s abilities and needs as long as the student requires O&M instruction or until the CVI completely resolves.

Regardless of the level of additional disabilities, children with CVI have the same right to services from a certified O&M specialist as their counterparts with ocular visual impairments. Independence must be a goal for all visually impaired students. The model for service delivery must, of course, include a great degree of consultation with a child’s primary caregivers and instructors, but eh O&M goals and objectives need to be determined by an educational team that includes an O&M instructor.

Charles has been receiving O&M instruction for two years, since his parents disagreed with the school psychologist’s impression about the presence of ADD. The O&M specialist assessed Charles and implemented a program to help him learn familiar indoor routes and to begin using simple maps to orient himself to unfamiliar areas in the school. Color adaptations helped Charles learn to look for important features of his indoor school environment, and now he moves through the hallways without the shiny yellow prompts. In his classroom, Charles is seated with his back to primary sources of light and he uses a slant board to help block out some of the visual information in the background. Charles continues to need adult assistance when the class goes on field trips, but as he becomes more skilled with his cane he seems to be willing to try to walk independently more often.

Texas School for the Blind & Visually Impaired

Outreach Program

tsbvi.edu

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Figure 7 U.S. Department of Education, Office of Special Education (OSEP) logo

"This project is supported by the U.S. Department of Education, Office of Special Education Programs (OSEP). Opinions expressed herein are those of the authors and do not necessarily represent the position of the U.S. Department of Education."

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Figure 3 Travel cane hangs on wall hook surrounded by a red frame

Figure 6 TSBVI Outreach Programs logo

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