Occupational Therapy Assessments of Cortical or Cerebral Visual Impairment: A Systematic Review
Authors
Orli Weisser-Pike, Anita Witt Mitchell, Leah Cordova
Main Research Question: CVI Assessment Tools in Occupational Therapy
This study investigates the measurement properties and clinical usefulness of various assessment tools for cortical or cerebral visual impairment (CVI) to determine their applicability in occupational therapy (OT) practice. Specifically, it seeks to identify the evidence supporting these tools and assess their strengths and weaknesses for evaluating children with CVI.
Key Findings
The systematic review identified 12 CVI assessment tools, evaluated across 15 studies. None of the tools demonstrated high-quality evidence for fundamental measurement properties like content validity, structural validity, or test-retest reliability.
- Three tools showed adequate construct validity (i.e., they measured what they were intended to measure).
- It is not certain if the items in most tools consistently measure the same thing. This is because researchers didn't use a specific method (confirmatory factor analysis) to test if the items fit together as expected.
- Some of these tools were developed for screening purposes, not assessment.
Responsiveness, which measures an instrument's ability to detect change over time, was not adequately examined in any of the studies. Furthermore, cross-cultural validity, which ensures applicability across diverse populations, remains unexplored. As a result, these limitations restrict the tools' reliability and practical utility for occupational therapy practitioners. Nonetheless, all 12 tools have potential, but further research is required to establish their robustness and clinical relevance.
Methodology
The review adhered to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidelines for systematic reviews of health measurement tools. Data came from MEDLINE via PubMed, Scopus, and Web of Science. The search spanned the databases’ inception to October 2020, focusing on studies involving pediatric participants and CVI assessments relevant to occupational therapy.
Researchers screened articles based on inclusion criteria, such as original research published in English, pediatric focus, and evaluation of CVI tools within the occupational therapy scope. They excluded studies if they reported prevalence data, focused on brain or visual functions beyond occupational therapy practice, or lacked measurement property evaluations.
Each study was appraised for methodological quality using the COSMIN Risk of Bias checklist (i.e., carefully reviewed to find what was done well and what could be improved in how the study was conducted). The quality of evidence for measurement properties was rated as "high," "moderate," "low," or "very low" following the COSMIN grading criteria, based on risk of bias, inconsistency, imprecision, and indirectness.
Significance of the Study
CVI is a leading cause of visual dysfunction in children worldwide, resulting in delayed development in motor skills, mobility, and social interactions. These delays significantly affect occupational participation in daily activities such as play, education, and socialization. The increasing survival rates of premature births and traumatic birth events, which are risk factors for CVI, have amplified the demand for effective assessment tools in clinical practice.
While various assessment tools have been developed, none are firmly rooted in occupational therapy frameworks. This systematic review emphasizes the importance of evidence-based tools tailored to the needs of children with CVI. Without reliable assessments, clinicians may struggle to identify and address the unique visual and functional challenges these children face.
Main Conclusions: More Research Needed to Evaluate CVI Tools for Clinical Use
- None of the CVI assessment tools currently meet the COSMIN criteria to be recommended unequivocally for occupational therapy. However, all tools have the potential to be recommended pending further research.
- Occupational therapists must use clinical judgment when utilizing these tools and consider their limitations when interpreting results.
- The study calls for rigorous, high-quality research to fill the gaps in evidence, particularly in areas of validity, reliability, and clinical utility.
In conclusion, while the reviewed tools provide a starting point for CVI assessment in occupational therapy, their application requires caution. It is critical to make future advancements in tool development and validation to improve outcomes for children with CVI.
Detailed Breakdown
Categorization of CVI Assessment Tools
The review identified 12 tools categorized into three types:
- Clinician-Reported Outcome Measures (ClinROMs)
Tools relying on professional judgment to assess behaviors or responses. - Patient-Reported Outcome Measures (PROMs)
Instruments where caregivers or patients provide information through questionnaires. - Performance-Based Outcome Measures (PerfOMs)
Tools involving defined tasks performed by the child and assessed by clinicians.
CVI Assessment Tools: Strengths/Weaknesses
- Flemish CVI Questionnaire
This PROM demonstrated acceptable construct validity through exploratory factor analysis but lacked confirmatory factor analysis evidence. Internal consistency was rated as adequate for most subscales but insufficient for some. - Insight Inventory
Although tested for convergent validity against cognitive and ophthalmic measures, its evidence was insufficient. No studies assessed its test-retest reliability or internal consistency. - Five Questions
Derived from the Structured History Taking Inventory, this PROM showed promising construct validity but lacked evidence for test-retest reliability. - Preverbal Visual Assessment (PreViAs)
Designed for children under two years old, it demonstrated sufficient content validity. However, its test-retest reliability and internal consistency evidence were rated as indeterminate. - Austin Playing Card Assessment
A PerfOM using playing cards to assess visual matching tasks, it showed potential in identifying differences between children with and without CVI. However, it lacked comprehensive validity and reliability evidence. - CVI Range
A ClinROM integrating performance-based elements, this tool demonstrated good internal consistency but lacked confirmatory factor analysis, rendering its evidence indeterminate. - Children’s Visual Impairment Test
This PerfOM demonstrated sufficient evidence of structural validity through confirmatory factor analysis but had inadequate internal consistency data for its subscales.
The remaining tools (e.g., EXPRESS CVI Inventory, Functional Questionnaire) displayed similar trends: limited evidence for essential measurement properties and insufficient validation studies.
Clinical Implications
Occupational therapy practitioners working with children with CVI must exercise caution when selecting and applying these tools. The lack of strong measurement properties and cross-cultural validity suggests that clinicians should use these assessments judiciously, relying heavily on clinical reasoning and judgment.
Although tools like the Flemish CVI Questionnaire and CVI Range show promise, their limitations must be considered. For example, some PROMs use complex scoring systems, while others target specific populations, limiting their generalizability. Tools like the Austin Playing Card Assessment and the Children’s Visual Impairment Test require symbolic understanding, which may not be feasible for younger children or those with cognitive impairments.
Practitioners should also be aware of practical barriers, such as the lack of standardized administration protocols or limited accessibility of some tools.
Research Gaps and Future Directions
The review highlights significant gaps in the evidence base for CVI assessment tools. Future research should focus on:
- Validation Studies: Robust confirmatory factor analysis and test-retest reliability studies are essential for establishing the tools’ credibility.
- Cross-Cultural Adaptation: Studies should evaluate the applicability of these tools in diverse cultural and linguistic settings.
- Development of Occupational Therapy-Specific Tools: Current tools lack grounding in occupational therapy frameworks. Developing theory-based assessments could enhance their relevance and utility.
- Responsiveness Evidence: The field needs longitudinal studies to assess the tools' ability to detect changes in visual and functional abilities over time.
Weisser-Pike O, Mitchell AW, Cordova L. Occupational Therapy Assessments of Cortical or Cerebral Visual Impairment: A Systematic Review. Am J Occup Ther. 2023 Nov 1;77(6):7706205160. doi: 10.5014/ajot.2023.050313. PMID: 37971385.