What assessments are currently used to investigate and diagnose cerebral visual impairment in children? A systematic review

Author: McConnell EL, Saunders KJ, & Little J-A.

Geographical coverage: Not reported

Sector: Biomedical

Sub-sector: Treatment

Equity focus: Children

Study population: Children aged 0-18

Review type: Other review

Quantitative synthesis method: Narrative synthesis

Qualitative synthesis method: Not applicable

Background: Cerebral visual impairment (CVI) is the leading cause of childhood visual impairment in the developed world. Despite this, there are no agreed clinical guidelines for the investigation and diagnosis of the condition. Before development of such guidelines can commence, it is important to recognise which approaches are currently employed.

Objectives: To evaluate the literature to identify which methods of assessment are currently used to investigate and diagnose childhood CVI.

Main findings:

Overall, authors found a lack of common practice in the approaches used by clinicians to investigate and diagnose CVI in children. At present, a ‘diagnosis of exclusion’ remains the most common means to diagnose CVI.

Of 6,454 identified articles, 45 met the inclusion criteria. From these, 10 categories of assessment utilised within included articles were identified: medical history, vision assessment/ophthalmologic examination, neuroimaging, visual behaviour and direct observation, structured history-taking, visual perception tests, ocular movement and posture assessment, intelligence/IQ assessment, clinical electrophysiology and neurodevelopmental tests. In terms of diagnostic criteria, the most commonly reported approach was one of exclusion, i.e., CVI was diagnosed when visual dysfunction could not be attributed to abnormalities detected in the anterior visual pathway.

Development of sector-agreed guidelines for the assessment and diagnosis of CVI may be considered an appropriate next step in an attempt to create some clarity on when to diagnose CVI. This will ensure children receive a timely diagnosis and ultimately receive the additional support they require. However, the challenge in creating such guidelines is acknowledged due to the heterogeneity of affected children.

Methodology:

This review aimed to identify and evaluate methods and tools used to diagnose Cerebral Visual Impairment (CVI) in children. The inclusion criteria for articles were: original research papers, conference abstracts or research protocols published in peer-reviewed scientific journals, or relevant textbooks; studies that included a clinical investigation of CVI in children aged 0–18 years; studies that provided an explanation or criteria to diagnose CVI; and studies specifically investigating cerebral/cortical visual impairment.

The literature search was conducted in January 2020 using databases such as Medline, EMBASE, CINAHL, Scopus, and the Cochrane Library. The search was limited to English language.

Two authors independently screened titles and abstracts for suitability. Full-texts of articles meeting the inclusion criteria were reviewed for eligibility. A data extraction tool was designed to gather publication characteristics, participant details, information on the type of tests and methods used during the CVI assessment, CVI diagnostic criteria, professionals involved in the assessment process, and main findings.

The review also graded the quality of articles based on the detail provided on how a CVI diagnosis was achieved and the professionals involved in the assessment. A quality assessment tool was developed for this purpose, using a simple three-point grading system.

In Each article was assigned a quality grade and a numerical score based on the tests used in their assessment. This score, ranging from 0 to 2, aimed to quantify the scope and depth of the CVI assessment, with a higher score indicating a more robust method. A total score of 20 was possible. A higher overall score doesn’t necessarily mean a better assessment but allows for a deeper evaluation of the methods used. All categories of assessment were given equal weight to avoid bias, even though some may be more appropriate for diagnosing CVI.

Applicability/external validity: Authors do not identify any limitations that may affect the applicability of this review.

Geographic focus: Search was unrestricted geographically but no information was provided on origin of included studies – or whether diagnostic techniques vary in different geographic contexts.

Summary of quality assessment:

There were a number of limitations in the approaches used to select, include and critically appraise studies. The search was limited to English and there is no evidence of relevant experts being contacted to identify further studies. While much of the assessment relating to the analysis of the data is not relevant to this review (which considers diagnostic approaches, rather than individuals), only one author extracted data from included studies. For these reasons, we attributed a low confidence in the findings of this review.