Development of a New Assessment for Cerebral or Cortical Visual Impairment: The Perkins CVI Protocol

Cerebral or cortical visual impairment (CVI) is a brain-based visual impairment caused by damage to the visual pathways or visual processing centers of the brain. CVI is the leading cause of childhood blindness in developed countries (Chang & Borchert, 2020). Despite this fact, “substantial barriers remain for evaluation, diagnosis, treatment, and education of this growing population of children and adults” (Lueck et al., 2023, p. 1).

CVI affects how visual information is processed and interpreted; it affects an individual's ability to look at and recognize their materials, environment, and the world around them. There are many known conditions that are associated with CVI, such as cerebral palsy, Down syndrome, and a range of genetic syndromes (Pehere et al., 2018; Wilton et al., 2021). One of the primary issues related to educational assessment of students with CVI is a lack of assessment tools (Lueck et al., 2023). Assessment is a key component of educational programs and can have multiple goals that range from initial screening to in-depth examination, as well as gathering of functional information about performance in order to make optimal decisions about students (Lueck et al., 2019). A quality assessment goes beyond examination of the use of vision; it also includes consideration for compensatory adaptations needed within the daily routine at times when the visual sense is not the primary mode for accessing information (Merabet et al., 2017; Roman-Lantzy & Lantzy, 2010).

The mission of the CVI Center at Perkins School for the Blind is to address the needs of children with CVI and the professionals who serve them. The approach of The CVI Center is research-based and whole-child-focused. In 2018, Perkins engaged Demosophia, a consulting agency whose mission is to “partner with organizations to help them address their most complex, messy, wicked problems using Structured Democratic Dialogue” (Christakis & Bausch, 2006) as one of their primary tools. Structured Democratic Dialogue (SDD) is a participatory design methodology that seeks to bring together diverse stakeholders to collectively address complex socio-technical problems (Christakis & Bausch, 2006). Each participant is invited to answer a triggering question to promote creative thinking and problem solving, and all responses are recorded. Ideas are clustered into categories and participants vote on the responses that resonate with them the most. Ultimately, through this process, the top issues become clear.

In 2018, Perkins convened a Co-Lab facilitated by Demosophia and brought together 25 international experts from the field of CVI including researchers, medical providers, educators, and parents to discuss how best to support people with CVI. These experts were purposely chosen for the disparate views each had related to CVI. The Co-Lab identified a variety of high-priority concrete needs, which included the need for more comprehensive CVI assessment tools. As a result of the Co-Lab process, Perkins decided to invest time and expertise into developing a new assessment tool, The Perkins CVI Protocol, which is hoped to meet the standards of validity and reliability over time. This paper will describe The Perkins CVI Protocol, an educational assessment that was developed based on current research and science. The path leading up to the development of the protocol will be described in this paper, as well as the components of the protocol process. In addition, a case study is provided to demonstrate how the Perkins CVI Protocol can be used for assessment and lead to individualized instructional planning.

The Perkins CVI Protocol

Given the charge to develop a more comprehensive assessment tool and drawing on the collective wisdom of leading experts in the field of CVI, the CVI Center identified 16 visual behaviors to describe CVI and the many ways an individual might be affected (Dutton & Lueck, 2015; Fazzi et al., 2007; Philip & Dutton, 2014; Roman-Lantzy, 2018; Zihl & Dutton, 2015). These behaviors serve as the foundation of understanding CVI, and it is through this lens that evaluation and support for individuals with CVI can be determined. As shown in Figure 1, the 16 visual behaviors are the foundation of the CVI assessment tool called the Perkins CVI Protocol. Each of the visual behaviors and compensatory strategies are ingrained in every section of the tool.

OPEN IN VIEWER

Figure 1.

CVI Visual Behaviors.

The Perkins CVI Protocol is designed to guide a teacher of students with visual impairments (TVI) by evaluating how a student is affected by CVI and what types of accommodations and supports would benefit the student. It is a new CVI assessment tool that is available for TVIs and can be used as a primary CVI assessment tool for a student's vision evaluation. A CVI assessment should be considered one component of the student's overall vision evaluation, which should also include a functional vision assessment (FVA) and a learning media assessment (LMA). The protocol assessment will be helpful in completing the FVA and LMA, since it will provide all the necessary insights that are particular to CVI. It should not, however, replace an FVA or LMA, since the protocol may not address all vision-based components. Instead, it will strengthen a student's overall vision evaluation.

The protocol consists of 10 sections. First, it includes overview information on each of the 16 visual behaviors and compensatory strategies. The purpose of this overview is to ensure that the TVI understands CVI and has a clear understanding about what is being assessed. Figure 2, entitled “The Perkins CVI Protocol Workflow,” shows the protocol assessment process. The Perkins CVI Protocol workflow shows the process from file review and student portrait to parent and team interviews, then observations followed by direct assessment. Information from each of those assessment steps is then included in the CVI evaluation report with recommendations, and there is also an optional step of the doctor letter.

OPEN IN VIEWER

Figure 2.

The Perkins CVI Protocol Workflow.

The Perkins CVI Protocol Workflow

The protocol is designed to guide the TVI through gathering background educational information and medical information from the student's parents or guardians, the educational team at school, as well as conducting a thorough file review.

Student Portrait

As part of this workflow, the TVI also provides the student's parents or guardians a “student portrait” to complete. The student portrait asks for information on the student's strengths and interests, medical and ocular history, communication skills, motoric skills, visual and compensatory skills, and parent concerns. The overview that a completed student portrait provides helps the TVI to build a whole-child understanding of the student.

During the development process, the student portrait was shared for review with eight medical providers and researchers from across the United States and two CVI educational experts. Feedback from the reviewers led to edits and additional questions that were added to the student portrait. The student portrait questions are primarily aimed at providing the TVI with the background information they need to begin the assessment.

Interviews

The next step in the process is for the TVI to complete a parent interview. Each question in the interview is supported by current research in the field of CVI and addresses one or multiple of the visual behaviors that are common in children with CVI. The parent interview is completed by the TVI, and it is designed to help teachers gain a better understanding of how the student is using their vision at home and in the community; as well as an understanding of the factors that affect access to visual information, such as clutter, presentation, and familiarity.

The protocol then asks the teacher to repeat the interview process with the student's educational team members in order to provide the TVI a better understanding of how the student is using their vision in school. Again, each question is rooted in one or more of the CVI visual behaviors. The questions can be asked to one or multiple team members who know the student well, such as the student's classroom teacher and their related service providers. The questions include asking for information on the types of materials the student is currently using at school and how the student is able to use their vision to access their materials, to navigate, and to interact with others.

Observations

Observations are the crucial next step in the protocol assessment process. They are meant to help the TVI more clearly determine how CVI is affecting the student across different activities, at different times of day, and in different environments. The information provided by observations will help the TVI to prioritize and plan the direct assessment. The protocol includes suggestions of what to look for when conducting formal observations, determined by each of the 16 visual behaviors. Observations help the TVI to discover if a student's use of vision is stronger at certain times of day; dependent on the activity itself; or if it fluctuates, depending on the amount of noise, motion, and clutter in the environment.

Direct Assessment

After observations, the protocol guides the user on creating a thorough and concrete plan for direct assessment based on the information the TVI has gathered during the assessment process. Similar to the observation section, the protocol includes a list of suggestions for activities to do during a direct assessment. The TVI can use that information to create the plan for the assessment. The protocol includes a sample assessment plan to further guide the TVI through the process.

CVI Evaluation Report and Recommendations

After the direct assessment, the TVI is guided through synthesizing the information from the direct assessment, as well as all the other components of the CVI evaluation, to help write a robust CVI evaluation report. This report creates a thorough picture of the student that can be shared with the student's parents and school team. Additionally, the report informs the development of the student's Individualized Education Program (IEP). The protocol includes a CVI evaluation report template to guide the TVI through the process.

The protocol includes three forms of recommendations that are consistent with what Perkins currently uses in their CVI evaluation reports. The recommendations are based on current research and recommendations of team members who have years of experience serving and assessing students with CVI. They are also inclusive of strategies that support the student based on each of the 16 visual behaviors and compensatory skills and have been curated by The CVI Center team. The last step of the protocol is to help guide the TVI to share the findings with the student's educational team at school, as well as parents and guardians. The protocol provides a sample summary document that the TVI may use to summarize the findings. Findings typically are categorized into four main areas: learning materials, social skills, navigation, and environment. The categories help to summarize how CVI affects the student's ability to access each of these areas and, most importantly, what strategies benefit the student.

A Practice Perspective

At Perkins, the Perkins CVI Protocol is being used to assess students who have been diagnosed with, or are suspected of having, CVI. Evaluators will look over the medical files of the students on campus to ensure that no student who should have a CVI assessment is being overlooked.

Based on a file review of a student at Perkins, the evaluator proceeded with a CVI evaluation, even though at the time the student was not suspected of having CVI by medical professionals or the student's educational team. The student has CHARGE syndrome, bilateral chorioretinal colobomas, and a visual acuity of 20/125. However, his ocular impairments did not seem to fully describe his functional vision. The protocol was used to thoroughly assess this student.

Through the assessment, the student displayed many visual behaviors that could be attributed to CVI. He demonstrated difficulties with visual recognition, especially for items and images that were slightly less familiar or a bit more abstract. The student also struggled with complexity and did best when presented with only two choices at a time. He showed difficulty visually following and perceiving an item or person in motion. Throughout the assessment, the evaluator noted that the student benefited from extra time to process, and he was greatly impacted by visual fatigue (e.g., about 20 min into the assessment, it started to take him a lot longer to look at the items that were presented to him).

This assessment helped to provide a thorough report with a list of appropriate recommendations for the student. This report was also shared with his medical providers; subsequently, the student was diagnosed with CVI. Most importantly, the report was shared with his parents who previously had not heard of CVI, but who expressed that, amidst the student's diagnoses, “the biggest challenge for us has been understanding his vision.” The CVI evaluation report created by following the steps in the Perkins CVI Protocol provided the student's parents, school team, and medical providers with clarity around the student's functional vision and the strategies that work best for him.

Summary and Conclusion

The Perkins CVI Protocol is an educational CVI assessment tool that guides a TVI through every step of conducting a thorough CVI evaluation. Seven trials have been conducted on the overall content, useability, and flow of the protocol. These evaluations or trials have led to numerous changes in the format and design of the protocol. A Perkins course has also been created to help guide users through the process. As of this writing, both the course and the protocol were set to be released simultaneously in September 2024.