Validity and Reliability of the CVI Range for Clinical Research: Baseline and One-Year Results
Authors: Melinda Y. Chang, Mark W. Reid, Christine Roman-Lantzy, Dilshad Contractor, Katherine Granger, Sharon H. O’Neil, Francesca Crozier-Fitzgerald, Martha Veto, and Mark S. Borchert.
Introduction
Cerebral/Cortical Visual Impairment (CVI) is one of the leading causes of visual impairment in children. Unlike many vision disorders that begin in the eyes, CVI results from differences in how the brain processes visual information. Because of this, a child may perform better on a traditional eye examination than expected based on how they function in everyday environments.
These real-world visual abilities are referred to as functional vision. For example, a child may be able to see a toy sitting alone on a table but have difficulty finding the same toy in a crowded toy box. Traditional vision tests often do not capture these challenges, making specialized functional vision assessments especially important for children with CVI.
For many years, educators and vision specialists have used the CVI Range, developed by Dr. Christine Roman-Lantzy, to evaluate functional vision and guide interventions. However, because it was often adapted to meet individual educational needs, it was difficult to use consistently in research studies. To address this need, researchers developed the CVI Range for Clinical Research (CVI Range-CR), a standardized version designed specifically for clinical studies and future treatment trials.
This study examined whether the CVI Range-CR is a dependable and meaningful tool for measuring functional vision in children with CVI.
Main Research Question
The researchers wanted to determine whether the CVI Range-CR could serve as a trustworthy outcome measure for future CVI research. Specifically, they asked:
1 Does the assessment produce consistent results when used by the same evaluator over time?
2 Do different evaluators generally reach similar conclusions?
3 Does the assessment accurately measure functional vision?
4 Can it detect meaningful changes in a child's functional vision over time?
Answering these questions is essential before using the tool in clinical trials that evaluate new therapies or interventions.
Methodology
To evaluate the CVI Range-CR, researchers followed 40 children with CVI between the ages of 12 months and 10 years. Each child participated in an assessment at the beginning of the study and again one year later.
During each visit, a trained neuropsychologist completed the CVI Range-CR, a structured functional vision assessment that combined a parent interview with observation and direct assessment of the child's visual behaviors. Children participated in a series of activities designed to evaluate ten characteristics of CVI, including:
- Color preference
- Need for movement
- Visual latency (slow visual responses)
- Visual field preferences
- Difficulty with visual complexity
- Need for light
- Difficulty viewing objects at a distance
- Atypical visual reflexes
- Difficulty with novel visual information
- Visually guided reaching
The assessment generated two overall scores:
- Rating 1 (Across-CVI Characteristics): A measure of functional vision across groups of CVI characteristics.
- Rating 2 (Within-CVI Characteristics): This score is calculated based on performance across the ten individual CVI characteristics.
Every assessment was video recorded. One trained examiner scored the assessment live, while expert remote graders independently scored the recordings. This allowed researchers to compare scores across different evaluators and determine how consistently the examiners scored.
The researchers also compared CVI Range-CR scores with other measures, including a Visual Behavior Scale (VBS) and the Vineland Adaptive Behavior Scales (VABS-III). The VBS score was assigned by a masked pediatric neuro-ophthalmologist based on the child’s ability to track objects of various sizes at various distances; it was considered a measure of visual acuity. The VABS-III is a parent questionnaire that assess adaptive function across multiple domains, including Socialization, Communication, Daily Living Skills, and Motor Skills. It also provides an overall adaptive behavior score.
Image Description: A young girl with a dark ponytail and glasses reaches for a yellow ball on a black floor mat.
Key Findings/Results
1 The CVI Range-CR Produced Consistent Results
One of the most important findings was that the CVI Range-CR was highly reliable, especially when the same examiner was used.
When a single examiner scored the same assessment at different times, the results were remarkably consistent (high intra-rater reliability). Different evaluators also generally reached similar conclusions when scoring the same child (inter-rater reliability). Small differences existed among graders, but overall agreement was strong. Notably, the differences in scores between graders was larger than the change in scores over one year.
2 The Assessment Measured a Coherent Concept
The ten CVI characteristics included in the assessment worked together effectively to measure functional vision.
Based on statistical analysis (McDonald’s ω, a measure of internal consistency), the researchers found strong evidence that the ten characteristics collectively measured a single underlying concept: functional vision.
3 Strong Evidence That the Assessment Measures What It Intends to Measure
The CVI Range-CR showed a strong relationship with clinical measures of visual behavior.
Children who demonstrated higher scores on the Visual Behavior Scale generally earned higher CVI Range-CR scores. This suggests that the assessment is capturing meaningful aspects of visual functioning rather than unrelated behaviors.
The assessment also correlated with adaptive skills measured by the Vineland Adaptive Behavior Scales (VABS-III), including communication, daily living skills, social interactions, and motor abilities.
These findings are important because they suggest that functional vision is related to functioning many areas of a child's everyday life.
4 The CVI Range-CR Detected Change Over Time
Over the course of one year, children showed small but measurable improvements in their CVI Range-CR scores.
Although the improvements were modest, the ability to detect change is critical for future intervention studies. Researchers need tools that can show whether a therapy, educational strategy, or medical treatment is helping children make progress.
Significance for CVI
This study addresses a major challenge in CVI research: measuring outcomes that truly matter in daily life.
Traditional vision assessments often focus on visual acuity—how clearly a child sees an object. While acuity is important, it represents only one aspect of vision. Many children with CVI struggle with visual processing challenges that affect learning, mobility, social participation, and independence.
A child may show little change on a standard eye chart yet become much better at recognizing faces, locating classroom materials, navigating crowded hallways, participating in play, or finding objects at home. These improvements can have a profound impact on quality of life, but they may not be captured by traditional eye examinations.
The CVI Range-CR was designed specifically to measure these functional abilities. By focusing on how children use vision in real-world situations, it provides a more meaningful picture of their everyday experiences.
Another important finding is that assessments can be recorded and scored remotely. This opens the door to centralized scoring systems for future clinical trials, helping ensure greater consistency across research sites.
For families, educators, and clinicians, this means that future CVI research may be better equipped to determine whether interventions truly improve a child's ability to function at home, in school, and in the community.
Conclusions
The study found that the CVI Range-CR is a reliable and valid measure of functional vision in children with CVI.
The assessment produced consistent results, correlated strongly with other measures of visual functioning, and was sensitive enough to detect changes over time. These findings support its use in future research studies and clinical trials.
The researchers also found that scores were most consistent when the same evaluator scored assessments over time. For this reason, future longitudinal studies may benefit from using the same grader or a centralized remote scoring system whenever possible.
Key Takeaways
- CVI affects how the brain processes visual information, not just how clearly the eyes see.
- Functional vision—the ability to use vision during everyday activities—is a critical outcome for children with CVI.
- The CVI Range-CR provides a standardized way to measure functional vision in research settings.
- The assessment demonstrated strong reliability and validity.
- Scores were closely related to other measures of visual functioning and adaptive behavior.
- The tool detected meaningful changes over a one-year period.
- Remote video scoring appears feasible and may improve consistency in future studies.
Chang, M. Y., Reid, M. W., Roman-Lantzy, C., Contractor, D., Granger, K., O'Neil, S. H., Crozier-Fitzgerald, F., Veto, M., & Borchert, M. S. (2026). Validity and Reliability of the CVI Range for Clinical Research: Baseline and One-Year Results. Ophthalmology science, 6(7), 101233. https://doi.org/10.1016/j.xops.2026.101233