Authors: Melinda Chang, Christine Roman-Lantzy, Sharon H. O’Neil, Mark W. Reid, and Mark S. Borchert
Publication: BMJ Open Ophthalmology, 2022;7:e001144
Article type: Peer-reviewed study protocol
Important Note:
This article describes how the researchers planned to evaluate the CVI Range-CR. It does not report participant results or establish that the assessment is valid and reliable. Those outcomes were reported after data collection and analysis.
Introduction
Cortical/cerebral visual impairment (CVI) is a leading cause of pediatric visual impairment in developed countries and is becoming increasingly recognized worldwide. CVI occurs when abnormalities or injury affecting the brain’s visual pathways interfere with vision. Children may have reduced acuity or visual fields, but they may also experience difficulties that ordinary eye tests do not adequately measure, including problems recognizing faces and objects, processing movement, managing visual complexity, interpreting novel visual content, or coordinating looking and reaching.
These varied manifestations make it difficult to summarize CVI severity with one conventional test. Measures such as preferential looking acuity tests and assessments of electrical activity like visual evoked potentials can estimate how clearly a child sees, but they do not show how the child interprets and responds to visual information in everyday situations. More comprehensive neuropsychological tests may require communicative or motor responses that are inaccessible to many children with CVI.
The CVI Range, developed by Christine Roman-Lantzy, addresses this gap by combining caregiver interview, observation, and direct assessment to examine ten characteristics associated with CVI. It is widely used in education to understand functional vision and guide individualized intervention. However, clinical research requires assessment procedures that can be administered and scored consistently across participants, examiners, locations, and time points.
The researchers therefore developed the CVI Range for Clinical Research, or CVI Range-CR—a standardized adaptation of The CVI Range intended for use as an outcome measure in clinical trials.
Main Research Question
The proposed study asks:
Can the CVI Range-CR provide a reliable and valid measure of functional vision in children with CVI when administered in a standardized clinical research setting?
The researchers planned to investigate three specific questions:
- Do different trained graders assign similar CVI Range-CR scores to the same child?
- Do CVI Range-CR scores correspond with an ophthalmologist’s rating of the child’s visual behavior?
- Can the assessment detect changes in functional vision over 12 months?
Methodology
The researchers planned a prospective longitudinal cohort study involving 45 children with CVI between 12 months and 8 years of age. Recruiting 45 participants was intended to leave at least 36 completed cases after allowing for as much as 20% attrition.
Participants would need an ophthalmologist-confirmed CVI diagnosis involving reduced acuity or visual-field function that could not be explained by the ocular examination alone. They would also need a known risk factor affecting the brain’s visual pathways, such as hypoxic-ischemic encephalopathy. Children with conditions that could prevent accurate behavioral assessment, including ophthalmoplegia or ocular motor apraxia, would be excluded. The interview was only available in English, so families not fluent in English were also excluded.
Each child would be assessed at baseline and again after 12 months. The evaluation included:
- A complete ophthalmological examination
- The six-level Visual Behaviour Scale (VBS)
- Parent questionnaires concerning medical history and vision services
- The Vineland Adaptive Behaviour Scales, Third Edition
- The CVI Range-CR
The VBS served as the primary comparison measure. It grades behaviors such as fixation and visual following. The Vineland measures broader adaptive functioning in communication, daily living, socialization, and motor development.
Image Description: The room used to conduct the CVI Range-CR during the study has a dark floor and plain walls with dark rectangular boards for isolating objects and printed images. A table and several chairs sit in the middle of the room.
The CVI Range-CR Assessment
The CVI Range-CR retained the ten characteristics of the original CVI Range:
1 Color preference
2 Need for movement
3 Visual latency
4 Visual-field preferences
5 Difficulty with visual complexity
6 Need for light
7 Difficulty with distance viewing
8 Atypical visual reflexes
9 Difficulty with visual novelty
10 Absence of visually guided reach
The researchers refined the CVI Range-CR from the standard CVI Range during a one-year pilot process involving assessment of 11 children with CVI. The final research protocol used a defined assessment room, standardized materials, a 24-question caregiver interview, and structured activities.
Activities examined responses to moving and stationary objects, illuminated targets, electronic images, mirrors, objects at different distances, auditory distraction, and increasingly complex visual arrays. For example, an examiner might first present one small object on a plain black tray and then gradually add more objects or a patterned background. This works somewhat like increasing the difficulty of a visual “Where’s Waldo?” task: the target remains present, but competing visual information makes it harder to locate.
Unlike the original CVI Range, the CVI Range-CR omitted a formal observation period in the child’s natural home or school environment. This decision supported standardization, although the examiner would continue watching the child’s spontaneous responses to objects placed around the assessment room.
Each child was given a score in two separate ratings, each ranging from 0 to 10, with higher scores representing more typical functional vision. The assessment used the two scoring approaches from the original CVI Range:
- Across-CVI Characteristics: The grader examines blocks of behaviors representing progressively more advanced functional vision.
- Within-CVI Characteristics: Each of the ten characteristics receives a domain score, which is added to produce a total.
Taken together, the pair of scores defined a range of visual ability. Scores were grouped into three phases: Phase I from 0–3, Phase II from 3–7, and Phase III from 7–10.
Remote Grading and Planned Analysis
Two iPads positioned at right angles would record each assessment. Videos would be synchronized, edited to emphasize important responses, and reviewed securely by remote graders.
The in-person neuropsychologist and two external graders—teachers of students with visual impairments trained in CVI Range administration—would score the assessments. At baseline, one remote grader would score each recording. At 12 months, both remote graders would score every recording, allowing the researchers to compare in-person and remote scoring and examine whether knowing a child’s previous score influenced later ratings.
The main outcome of the proposed study was to determine inter-rater reliability of the CVI Range-CR, calculated using an intraclass correlation coefficient. In simple terms, this statistic asks whether different judges watching the same performance reach similar conclusions.
To examine validity, the researchers planned to compare CVI Range-CR scores with VBS ratings. They would also consider age, adaptive behavior, and frequency of vision services as possible influences. Baseline and 12-month scores would be compared to determine whether the assessment could measure longitudinal change.
Key Findings
Two iPads positioned at right angles would record each assessment. Videos would be synchronized, edited to emphasize important responses, and reviewed securely by remote graders.
Because this is a protocol paper, it contains no study findings. Its primary contributions are to establish:
- A detailed, replicable version of the CVI Range for research
- Standard materials, activities, room configuration, and interview questions
- A procedure for recording and remotely grading assessments
- A plan for examining agreement among graders
- A plan for comparing functional-vision scores with clinical visual behavior
- A framework for measuring change over time
The article cites earlier research reporting excellent reliability for the original CVI Range. However, that study had limitations, including inconsistent assessment settings, limited masking, and insufficient standardization. The CVI Range-CR protocol was designed to address those concerns.
Significance for CVI
A reliable measure of functional vision is essential for evaluating CVI interventions. An acuity score alone is like measuring whether someone can read the letters on a road sign without asking whether they can find the sign in a crowded landscape. A successful CVI intervention should improve not only what a child detects, but how the child uses vision during learning, communication, mobility, and daily activities.
Standardized video recording could also support centralized grading in multicenter research. Children could be assessed at different locations while trained graders apply consistent criteria. This could reduce variability and make clinical-trial findings more trustworthy.
However, standardization creates tradeoffs. Removing natural-environment observation makes the assessment easier to replicate but may reduce information about how the child functions in familiar routines. The CVI Range-CR should therefore be understood as a research adaptation, not a direct replacement for a comprehensive educational functional vision assessment.
Conclusions
This protocol establishes a systematic plan for evaluating the CVI Range-CR as a research outcome measure. It responds to an important need for assessments that capture the real-world visual effects of CVI and can be administered consistently across sites and time.
The paper itself does not prove reliability or validity. Its importance lies in defining the assessment and creating a rigorous pathway for testing it.
Key Takeaways
- The CVI Range-CR is a standardized research adaptation of the original CVI Range.
- It evaluates ten CVI characteristics through caregiver interview and structured activities.
- It was designed for video recording and centralized remote grading.
- The planned study included 45 children assessed at baseline and 12 months.
- Reliability would be determined by comparing scores from different graders.
- Validity would be explored through comparison with clinical visual-behavior ratings.
- This 2022 article is a study protocol and contains no validation results.
- Findings about the CVI Range-CR should not automatically be generalized to every administration of the original educational CVI Range.
Chang, M., Roman-Lantzy, C., O’Neil, S. H., Reid, M. W., & Borchert, M. S. (2022). Validity and reliability of CVI Range assessment for Clinical Research (CVI Range-CR): a longitudinal cohort study. BMJ Open Ophthalmology, 7(1), e001144. https://doi.org/10.1136/