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Functional Visual Assessment & Beyond

Functional Vision Assessment and Beyond: An Overview of Key Steps for Teachers in the Educational Assessment of Students With CVI

by Amanda Lueck, Ph.D.

This introduction to functional visual assessment has been written by Dr Amanda Lueck for you to use and share at no cost. Whilst reasonably short, there are many links to 'dive-deeper', all leading to the published sources. This was first published in the Summer 2021 CTEBVI Journal (California Transcribers & Educators for the Blind & Visually Impaired) which holds the copyright but has given us permission to share it with you, for you to use and utilise in your local area. Different countries and regions have different resources, so you can use it as a template or structure, or as it is. Many thanks to Dr Lueck for this generous gift to the CVI community.

INTRODUCTION

Understanding students who have CVI can be complicated since observed behaviors can be associated with a variety of conditions. In addition, manifestations of CVI can be wide-ranging, affecting many areas of visual and overall performance. Careful assessment involving multiple methods is the key to unlocking the learning needs of these students. This paper presents a brief overview of steps that guide the identification of behavioral outcomes related to CVI that help to determine appropriate intervention practices. For those who wish to take a deeper dive into specific topics, references are provided along with highlighted links to online information.

For students with CVI, educational assessment is a process that characterizes how a student performs, i.e., what a student can and cannot do, leading to interventions created to foster learning and growth. Furthermore, systematic assessment practices may reveal CVI-related behaviors that provide insights that de-mystify why a student operates in a certain way. In addition, by ruling out behavioral outcomes associated with CVI that are not relevant for a particular student (e.g., some students with dorsal stream dysfunction may have difficulty with eye-hand coordination, while others may not) the parameters of a student's CVI are more clearly defined so that more effective intervention strategies can be devised.

For an example, see Dr. Amanda Lueck's Guest Blog.

While this paper has a strong focus on tying the contents of a comprehensive Functional Vision Assessment (FVA) by qualified educators to appropriate interventions, it is also imperative to recognize that CVI affects more than a person's vision. It can affect the attainment of milestones in all developmental domains for young children now and in the future (Lueck, Chen, & Hartmann, in press) as well as access to learning, social interactions, curricular competence, feelings of well-being, self-determination, and quality of life for all students. The ways in which CVI influences these factors varies for each student, requiring thoughtful and thorough knowledge about how students function in their home, school, and community, and how they and those around them understand their CVI.

More detailed information is provided in an extensive foundational course on CVI developed and presented online through the Pennsylvania Training and Technical Assistance Network. The descriptions and links to these PaTTAN webinars can be found on this website: PaTTAN's CVI Course

STEPS IN THE EVALUATION PROCESS

STEP 1: Review of Medical and Educational Records: Understanding the Root-Causes of Observed Behaviors

Medical and educational records provide critical information about visual performance and learning challenges. Understanding the root-cause of a student's brain-based visual impairment leads to interventions that have maximum impact because they provide information that leads to interventions that take into account the underlying bases for documented behaviors. Root-causes may be organic (e.g., underdevelopment white matter in the ventricles of the brain) or they may be revealed from reported patterns of behaviors that have led to other verified diagnoses (e.g., autism spectrum disorder, central auditory processing disorder).

Step 1a: Review of records to discover underlying physical conditions and other medical and educational diagnoses in order to understand the root-causes of observed behaviors

Here it is important to identify behaviors that may be related to CVI vs. other diagnostic alternatives in order to pinpoint appropriate methods of instruction. Knowing 'what to look for' is the key. Sometimes outcomes related to CVI may be overlooked and attributed to other underlying conditions. When this happens, proposed interventions may not address a student's underlying needs.

The information below, for example, provides suggestions of 'what to look for' when medical records provide results of brain MRI scans. As the evaluation progresses, it often becomes clear which underlying physical and learning factors come into play and where it might be necessary to rethink previous educational diagnoses.

Visual Features of CVI to Consider Looking for in Relation to Damage in Speciufic Brain Locations Reported on a Brain MRI Scan

Area of the Brain Seen on MRI Scan (in bold)
Visual Features to Look Out For (under)

Damage to the Occipital Lobes

Left occipital lobe
Lack of visual field on the right side for both eyes

Right occipital lobe
Lack of visual field on the left side for both eyes

Both occipital lobes
Impaired central visual functions of acuity, contrast, and color
Lack of visual field on both sides (often manifesting as visual field constriction)
Severe damage causes profound visual impairment

Damage to the Posterior Parietal Lobes

Left posterior parietal lobe
A tendency to miss people and events on the right side
Intermittent lack of attention on the right side
A tendency to bump into people and objects on the right side, especially when upset or tired
Reduced accuracy of visual guidance of movement of the right side of the body
A tendency to be left-handed (because this becomes the dominant hand)
Weakness of the right side of the body (as a result of damage further forward in the brain)
Difficulties with spoken or written language (because the left parietal lobe serves language)
When drawing, the right side of the picture can be distorted

Right posterior parietal lobe
People and events on the left side are frequently missed
Significant lack of attention on the left side and intermittent lack of attention on the right side
People and objects on the left side are frequently bumped in to
A tendency to be right-handed
Weakness of the left side of the body

Extensive Damage to Both Posterior Parietal Lobes
Inability to see and give attention to more than one or two items in a visual scene at once (simultanagnosia), despite the requisite visual field
Inability to use vision to guide movement, accurately despite sometimes having clear three-dimensional vision (stereopsis), in rare cases, resulting in colliding with walls and obstacles, bumping into people and objects, and not being aware of drop-offs
Noise or conversation can make the child lose visual attention
Inability to move the eyes from one target to another at will, despite ability to move the eyes
Profound lack of ability to see moving targets is common
Lack of lower visual field below the horizontal midline
Impaired movement of all four limbs as a result of quadriplegic cerebral palsy is common

Limited damage to the white matter of both parietal lobes
Lack of ability to see moving targets is occasionally observed
Lack of the peripheral lower visual field means that the feet cannot be seen while walking
Impaired ability to move feet over floor boundaries, or walking round patterns despite looking at them, suggests optic ataxia of the lower limbs
Reaching for patterns on plates as if they are three-dimensional is observed in some young children
Difficulty finding toys in a toy box, or an item of clothes in a pile of clothes
Difficulty finding a relative or a friend in a group of people
Easily gets lost in crowded places
Reading is made easier by increased spacing

Damage to the Temporal Lobes
The patterns described for damage to one side apply to acquired damage but can be variable. Damage from birth tends to affect all forms of recognition.

Left temporal lobe
Impaired shape recognition (shape agnosia)
Impaired object recognition; (object agnosia) color recognition may be used to compensate
Impaired recognition of the shape of letters

Right Temporal lobe
Impaired face recognition (prosopagnosia)
Impaired ability to see meaning in facial expressions
Difficulty being orientated (may be profound) and navigating known environments (topographic agnosia)

Both temporal lobes
Combination of the impaired abilities described for the left and right temporal lobes (integrative agnosia)
Difficulty knowing the length and orientation of lines, or size of objects
Impaired visual memory (often with reliance on auditory memory and language ability)

Adapted for CVI Scotland website, from Dutton, G. N. (2015). Disorders of the brain and how they can affect vision. In A. H. Lueck & G. N. Dutton (Eds.), Vision & the brain: Understanding cerebral visual impairment in children (p. 78-79). NY: APH Press.

Step 1b: Review medical and educational records of visual performance to understand basic visual functions as well as behaviors related to visual perception

It is critical to have information about a student's:

  • visual acuity
  • visual field
  • contrast sensitivity
  • illumination sensitivity
  • color identification
  • oculomotor functioning
  • refractive error ("What is the refractive error?" and "If the student is wearing prescribed corrective lenses?")
  • accommodation insufficiency

With this information, it is possible to tease out behaviors that may be associated with basic visual functions (which can be present for both ocular and brain-based visual impairments) from behaviors resulting from visual perceptual or other causes.

Often information associated with more complex visual perceptual functions related to brain-based visual impairments may not be available in medical and educational records, and must be gathered during the educational Functional Vision Assessment (FVA) and Learning Media Assessment (LMA), the next steps in the process.

It is important to consider behavioral outcomes due to basic visual functions as well as those due to visual perceptual concerns in order to design appropriate interventions. Moreover, a combination of these issues may be involved. For example, when a child cannot see a parent in a crowd, it could be due to such things as:

  • reduced visual acuity (inability to see details at a distance),
  • reduced contrast sensitivity (features may blend together due to inability to see differences in the brightness of adjacent surfaces),
  • visual field impairment (limited field of view so that parent's position relative to the crowd may not be noted),
  • oculomotor concerns (e.g., may affect ability to scan parts of the field of view),
  • visual neglect (inattention to specific portions of the visual field),
  • inability to see more than a few objects at a time (i.e., simultanagnosia).

Collecting information on all these potential influences helps to identify more precisely those that impact the student's performance and thus lead to insightful interventions to assist the student.

STEP 2: Complete a Comprehensive Functional Vision Assessment (FVA) and Learning Media Assessment (LMA)

Step 2a: Collate Findings from Multiple Methods of Assessment to Develop a Profile Unique to Each Student

Although this step comes after all information has been gathered, it is mentioned here first in order to emphasize the importance of assembling and organizing data from all records and all assessment sources in order to paint a comprehensive and accurate profile of a student who has CVI. Every assessment, observation, or interview has something to add to the profile through the addition, corroboration and coordination of findings

Educational Functional Vision Assessment (FVA): A full FVA for a student with CVI includes conducting a typical functional vision assessment of basic visual functions as well as one that targets visual perception and other issues for students who have CVI. The Educational FVA complements evaluations completed during clinical eye examinations as well as any assessments completed by other specialists such as occupational therapists, neuropsychologists, speech-language therapists, physical therapists, and orientation and mobility specialists.

Learning Media Assessment (LMA): The LMA provides a way to discover how a student applies vision to learning tasks and/or daily routines and can provide insights into ways to offer various curricular options to increase accessibility and maximize learning at a student's grade or developmental level.

For example, here is a link to a summary form, presented as a Literacy Profile, based on findings that incorporate a range of results. It can be used to design optimal literacy programs for students who have CVI and is found at the TEACHCVI website: TEACHCVI Teaching Materials; Literacy Profile.

IMPORTANT NOTE ON DISPARATE FINDINGS: When evaluations show different results in the non-clinical vs. the clinical setting, one can examine possible contributing factors such as:

  • environmental differences (e.g., lighting, visual clutter, noise level; See Tietjen, 2019),
  • differences in content and presentation format of assessment tools used, as well as their administration methods and response modes
  • student's comfort level with people or places
  • student's physical state (e.g., hungry, tired, ill, discomfort due to pain, physical positioning)

Any noted differences can be discussed with the eye care provider as necessary. Critically, differences that lead to stronger performance results during different evaluations can be infused into the design of optimal instructional programs

Dorsal and Ventral Streams: Researchers have examined how visual signals flow from the eyes to the brain. The signals that reach the occipital lobe at the back of the brain (and even earlier) are thought to travel through neural networks or pathways to other parts of the brain that help organize and make sense of incoming signals. One explanation that described how these networks function involves what have been called the dorsal and ventral streams.

For a quick review of the dorsal and ventral stream processing considerations, please see: CVI Now. Higher-order visual pathways and the CVI brain. Perkins School for the Blind.

If a dorsal or ventral stream concern is uncovered during a student's evaluation, looking for other indicators associated with dorsal or ventral stream processing may reveal additional behavioral consequences of CVI that have might otherwise been overlooked. Diagrams 1 and 2 serve as quick guides to identify potential dorsal or ventral stream dysfunctions to consider for observation and evaluation.

Diagram 1: Patterns of Behavior Associated Perceptual Visual Disorders Related to Dorsal Stream Dysfunction

Vision & the brain: Understanding cerebral visual impairment in children. Louisville, KY: APH Press. All rights reserved. (p. 234)

This figure refers to focal pathology, affecting elements of the dorsal stream. (Many children identified with CVI show some features of dorsal stream dysfunction, but other features may be masked by ones that are more severe.)

These features can occur in any number, combination, or degree, but when one is identified all the others need to be sought. Affected individuals have no awareness of these dysfunctions, unless specifically taught about them. Since these disordered functions are unconscious ones, they cannot be aware of a lack or loss of what they never knew they had (anosagnosia).

Reprinted from Lueck, A. H. & Dutton, G.N. (Eds.) (2015). Vision & the brain: Understanding cerebral visual impairment in children. Louisville, KY: APH Press. All rights reserved. (p. 234).

Diagram 2: Patterns of Behavior Associated with Perceptual Visual Disorders Related to Ventral Stream Dysfunction

Vision & the brain: Understanding cerebral visual impairment in children. Louisville, KY: APH Press. All rights reserved. (p. 235).

This figure refers to ostensibly isolated ventral stream damage due to focal pathology affecting ventral stream functions. Total ventral stream pathology is usually associated with low visual acuities due to concomitant damage to the occipital lobes. Innate orientation can be spared or impaired to a variable degree, leading to easily getting lost even in well-known environments. The features listed in the rectangular boxes highlight the nature of complete (or total lack of function) and incomplete or partial lack of function.

Reprinted from Lueck, A. H. & Dutton, G.N. (Eds.) (2015). Vision & the brain: Understanding cerebral visual impairment in children. Louisville, KY: APH Press. All rights reserved. (p. 235).

Manifestations of CVI: As researchers, practitioners, caregivers, and those with CVI have learned more about the condition and its effects, a wide array of CVI possible manifestations have been identified. The list below has 16 principal categories of potential manifestations of CVI.

Manifestations of CVI: CVI Profile

CVI Profile Categories

  • Clarity of Vision
  • Area of Vision
  • Color
  • Following People or Objects Visually Due to Eye Movement Limitations or Visual Field Restrictions
  • Depth Perception
  • Locating People or Objects Visually/Visual Search Capabilities
  • Illumination
  • Response to Faces
  • Response to Sounds
  • Recognition of Objects or Symbols
  • Response to Environment
  • Response to Movement
  • Effects of Visual Novelty
  • Accuracy of Visual Motor Planning & Control
  • Response Time
  • Imitating & Copying

Adapted from Lueck, A., Chen, D., Hartmann, E. (in press) CVI Companion Guide to the Developmental Guidelines for Infants with Visual Impairments. Louisville, KY: APH Press © All rights reserved.

A more complete description of over 50 consequences of CVI that go beyond vision performance to include auditory and social interaction concerns can be found in the PaTTAN webcast, Students with CVI: The CVI Profile (see below):

Video: Students with CVI: The CVI Profile. Click 'Watch on YouTube' (above) and this video will open in a new window on your device.Video Link: https://www.youtu.be/KNJ7qHz09KE

Step 2b: Formal/Informal Assessment

There are a number of accepted methods to assess basic visual functions commonly used by teachers of students who have visual impairments (e.g., Erin & Corn, 2010). These can and should be applied to students who have CVI. Results can be interpreted in light of additional factors that are consequences of a student's CVI. For example, if a student has difficulty with visual clutter, results from assessment tools that require viewing crowded material must be interpreted with that in mind. It should be stressed that changing any presentation formats of standardized tests (e.g., skipping items, covering portions of the text, asking for verbal responses only), negate the validity of any comparison scores unless these adaptions were included in the standardization process by the test developers.

Assessment tools addressing visual perceptual concerns for students with CVI are increasing. It is recommended that a variety of assessment methods be used to examine the behavioral consequences of CVI since no single tool currently covers all possible CVI manifestations, and new assessment techniques are coming out all the time (see examples of tools in use in Lueck, Dutton, & Chokron, 2019).

For more information about educational assessments tools for students who have CVI and interpreting assessments findings from non-CVI assessment tools, see the PaTTAN webcast, More on Assessment for Children with CVI (see below):

Video: More on Assessment for Children with CVIVideo Link: https://www.youtu.be/Xs4wW3B_tfk

For a helpful review of current evidence-based assessment tools for students who have CVI see: Bauer, 2019. CVI Session 3. Click on to Fundamentals of CVI (3)

Step 2c: Observation and Interviews/History-Taking

Insightful observation and interviews can be used to gather information about students who have CVI. Interview and history-taking guides are available from a variety of sources (see Lueck, Dutton, Chokron, 2019). Interviews provide information from caregivers who know the student well and can also include information provided by the students themselves when possible.

Coupled with interviews, observations can provide important information about a student's performance. Observations can be conducted in conjunction with assessments specific to CVI, but also within the context of other assessment protocols, during instruction time, or during daily routines in the home, school, and community. Behaviors that are 'missed' during the administration of assessment tools and interviews can come to the fore during careful observations. This includes observations for students who are in academic, pre-academic and functional academic programs as well as young children in early intervention programs. A parent or teacher with keen observation skills can be on the lookout for examples of behaviors associated with CVI. In addition, parents and teachers may find behaviors that do not conform to what they expect. Rather than discarding these findings, it is important to re-examine them to see if they indeed might be an expression of a student's form of CVI. They might hold the key to unlocking the reasons underlying a student's behavior.

Examples of history-taking can be found in the PaTTAN webinar: More on Assessment of Children with CVI (see below)

Video: More on Assessment of Children with CVIVideo Link: https://www.youtu.be/Xs4wW3B_tfk

STEP 3: Develop Individualized Education Program (IEP) or Individualized Family Service Plan (IFSP) Goals

Determining educational goals for school-age students or early intervention goals for infants and toddlers is the next step in the process. Interventions to achieve targeted goals (i.e., accommodations and/or direct instruction) are best integrated into core curriculum requirements and expanded core curriculum priorities for school-age students or within targeted activities during daily routines for younger children that reflect family priorities (Lueck, Chen, & Hartmann, in press). As such, the design of a multidimensional intervention program for a student with CVI is a team process combining assessment data and experiences from all who interact with the student and whenever possible the student's expressed needs.

How the goals are addressed with respect to a student's CVI are unique to each student's abilities, and curricular demands. For younger children, they are based on developmental levels and family priorities. Although there are interventions that address specific needs of students with CVI, such as the reduction of visual clutter or the need to speak more slowly for those who have auditory processing issues, many interventions developed for students who have ocular visual impairment can be implemented with students who have CVI. These may include the use of large print, use of magnification devices, use of line markers when reading, simplification of workbooks, highlighting crucial visual cues, training in eye-hand or eye-foot coordination, instruction in visual scanning techniques, use of orientation and mobility devices and techniques, and more. Intervention methods must be matched to the identified needs of each student along with their skills and abilities. The underlying reasons for implementing particular intervention strategies, however, will depend upon the root-causes of a student's condition. Most importantly, educators and caregivers must understand what interventions will help and what interventions might actually interfere with learning since not all intervention approaches discussed as relevant for students with CVI may be pertinent for a particular student.

To consider the unique needs of each student with CVI is key. This is illustrated in this blog by an older student with CVI, found on this website: Yellowstone's Blog (1)

STEP 4: Monitor Progress and Diagnostic Teaching

Monitoring progress toward intervention goals is critical. Goals and methods may need to be adjusted if the chosen intervention methods are not effective or if students' skills and/or curricular demands or priorities change. A large number of intervention methods specific to students who have CVI are either available or under development, but the evidence-base for many interventions is limited. Until more evidence exists about successful intervention techniques and the types of students with CVI they can assist, it is incumbent upon teachers to devise their own methods to evaluate instruction to determine what works, what doesn't work, and what needs to be modified to promote optimal development and learning.

The use of Diagnostic Teaching methods is one systematic way to monitor the effects of instruction. Because each student with CVI is so unique, this method lends itself to individualized evaluation of highly specific goals and methods adapted to the unique needs of each student. Diagnostic Teaching was first mentioned in the field of visual impairments by Koenig & Holbrook (1993) in their work on learning media assessment. According to these authors, 'Diagnostic Teaching simply guides a teacher's instructional practices as though each interaction with a student, whether instructional or not, is an opportunity to engage in integrated assessment. p.15'. Assessment and instruction inform one another. Here teachers develop initial hypotheses for teaching practices and monitor them for possible adjustments. Once a teaching hypothesis is formulated (e.g., Maria, a 7-year-old girl in 2nd grade, will read more fluidly and accurately when the reading material is placed to the left of midline since she does not attend to material to her right due to visual neglect.). Observations are made to maximize the learning environment for Maria, instructional methods are systematized, and quantitative or qualitative outcome data are collected regularly. Based on this, interventions are continuously reviewed and refined as needed.

More examples of Diagnostic Teaching for students with CVI can be found in the following PaTTAN webinar, Multidimensional Intervention Approaches for Students who have CVI (see below):

Video: Multidimensional Intervention Approaches for Students who have CVIVideo Link: https://www.youtu.be/wWYBKCxZULI

CONCLUSION

Assessment of students with CVI requires a system that provides evidence about how a student behaves and learns gathered from a variety of assessment methods and specialists. It requires multiple methods of assessment and sensitive interpretation of assessment findings that culminates in a cohesive and complete picture of the student with CVI. This carefully-crafted holistic picture leads to the development of effective instructional programs and a more robust understanding of a student's CVI by all providers, caregivers, peers, the student themselves.

REFERENCES

  • Bauer, C. (2019). Fundamentals CVI Session 3, Tests of Functional Vision in CVI: Evidence Based Approaches, Western Region Early Intervention Conference
  • http://www.wreic.org/cvi-brain-development.html (retrieved June 13, 2021).
  • Erin, J.N., & Corn, A.L., (2010). Foundations of low vision: Clinical & functional perspectives. Second edition. Louisville, KY: APH Press.
  • Koenig, A., Holbrook, M.C. (1993). Learning media assessment. Austin, TX: Texas School for the Blind and Visually Impaired.
  • Lueck, A.H., Chen, D., & Hartmann, E. (in press). CVI Companion Guide to the Developmental guidelines for infants with visual impairments: A manual for early intervention. Louisville, KY. APH Press.
  • Lueck, A.H., Dutton, G.N., Chokron, S. (2019). Understanding children with cerebral visual impairment using multiple methods of assessment. Seminars in Pediatric Neurology, 31, 5-14. DOI: 10.1016/j.spen.2019.05.003
  • Tietjen, M. (2019). The "What's the Complexity?" Framework. In Roman-Lantzy, Christine. (2019) Cortical Visual Impairment: Advanced Principles (pp. 92-150). Louisville, KY: APH Press

Dr Amanda Lueck is a USA expert in the education of children with CVI, and has a distinguished career as both a researcher and professor.Dr Amanda Lueck is a USA expert in the education of children with CVI, and has a distinguished career as both a researcher and professor.

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At CVI Scotland we are devoted to helping people understand cerebral visual impairments, and together working towards developing the understanding of this complex condition.