Dataset Information

Improving outcomes for primary school children at risk of cerebral visual impairments (the CVI project): study protocol for the process evaluation of a feasibility cluster-randomised controlled trial.

ABSTRACT:

Introduction

Brain-related visual impairments, also known as cerebral visual impairment (CVI), are related to damage or poor function in the vision-related areas of the brain. There is broad agreement that CVI is an appropriate term to describe visual impairments that are not accounted by disorders of the eye or optic nerve, but differences remain as to which impairments can be included in this term. The CVI project is a programme of work that includes the development of a complex intervention to share knowledge with teachers, so that they can make both targeted and universal changes to support children with CVI. A feasibility study for a cluster-randomised controlled trial to evaluate this intervention is underway. This paper describes the protocol for an accompanying process evaluation to explore how the intervention is implemented and provide context for the interpretation of the feasibility trial outcomes.

Methods and analysis

A logic model has been developed to guide data collection. Both qualitative and quantitative data will be collected to assess the feasibility and acceptability of the intervention, the study design and explore how any changes that occur are brought about. Interviews with key primary school staff and parents will investigate responses to the intervention and trial processes. Surveys will collect data on intervention implementation and knowledge of CVI. Photographs of classroom walls will document any changes to visual clutter and document analysis will look for changes to school special educational needs and disability (SEND) policies.

Ethics and dissemination

Ethical approval was granted by the University of Bristol Faculty of Health Sciences Ethics Committee. Findings will contribute to the development of a full-scale cluster-randomised controlled trial to assess the effectiveness of the intervention with adequate statistical power. The results will also support the refinement of the intervention and its underlying theory.

SUBMITTER: Pease A

PROVIDER: S-EPMC8103382 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:IntroductionCerebral visual impairment (CVI) refers to a spectrum of brain-related vision problems. CVI is associated with poor educational and mental health outcomes. An intervention has been developed to help children with CVI, involving input from clinicians, teachers and parents. The effectiveness of this intervention needs to be evaluated. This study aims to guide any refinements to the intervention or the design of a future cluster-randomised trial that may be needed.Methods and analysisThis study will include all methods anticipated for a future cluster-randomised controlled trial. Eight primary schools will be recruited and randomised to receive the intervention or carry on with usual practice. The intervention will comprise an information pack for schools and access to a local paediatric ophthalmology clinic (who are prepared to assess them for CVI), for up to 5% of participating children. Outcome assessments will be carried out at baseline (before randomisation) and after 4-5 months of intervention period. Assessments will include children's self-reported quality of life, their learning ability and behaviour as reported by teachers, and family functioning reported by parents. Cost data will include service use, family expenditure on additional support (eg, private appointments and administration) and school spending and resource used in helping children with special educational needs or disability. A process evaluation (PE) will collect additional data relating to the implementation of the intervention and the trial processes, in the school and clinic settings. The protocol for the PE will be reported separately.Ethics and disseminationEthical permission was obtained from the University of Bristol Faculty of Health Sciences Ethical Committee. The results will inform the design of a future trial to assess the effectiveness and cost-effectiveness of the intervention and will be shared with participants, CVI-support groups and peer-viewed journals.Trial registration numberISRCTN13762177; Pre-results.

Project description:PurposeCerebral 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. This systematic review evaluated the literature to identify which methods of assessment are currently used to investigate and diagnose childhood CVI.MethodsMedline, Embase, CINAHL, Scopus and the Cochrane Library databases were systematically searched in January 2020 using defined search terms. Articles were included if they: (i) were research papers, conference abstracts or research protocols published in peer-reviewed scientific journals, or relevant textbooks; (ii) included a clinical investigation of CVI in children; (iii) provided an explanation or criteria to diagnose CVI and (iv) were specifically investigating cerebral/cortical visual impairment. Methods used to a) assess and b) diagnose CVI were extracted from included articles. 'Assessment scores' were assigned for each method employed by researchers to investigate and diagnose CVI to quantify and compare approaches between articles. A quality grading was also applied to each article.ResultsOf 6454 identified articles, 45 met the inclusion criteria. From these, 10 categories of assessment utilised within included articles were identified: (1) Medical history, (2) Vision assessment/ophthalmologic examination, (3) Neuroimaging, (4) Visual behaviour and direct observation, (5) Structured history-taking, (6) Visual perception tests, (7) Ocular movement and posture assessment, (8) Intelligence/IQ assessment, (9) Clinical electrophysiology and (10) 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.ConclusionThere is 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. Development of clinical guidelines for assessment and diagnosis are necessary to ensure consistency in the diagnosis of CVI and the timely implementation of support to alleviate the impact of CVI on the child's daily living.

Project description:ObjectivesCerebral visual impairment (CVI) comprises a heterogeneous group of brain-related vision problems. A core outcome set (COS) represents the most important condition-specific outcomes according to patients, carers, professionals and researchers. We aimed to produce a COS for studies evaluating interventions for children with CVI, to increase the relevance of research for families and professionals and thereby to improve outcomes for affected children.DesignWe used methods recommended by the Core Outcome Measures in Effectiveness Trials Initiative. These included a proportionate literature review of outcomes used in previous studies; qualitative interviews with children and families; a two-round Delphi survey involving parents, children and professionals and a consensus meeting to ratify the most important outcomes.SettingTelephone interviews and online Delphi surveys of participants who all lived in UK or Eire.ParticipantsEighteen parents and six young people were interviewed. Delphi participants (n=80 did both rounds) included professionals working with children who have CVI (teachers, orthoptists, ophthalmologists, optometrists, qualified teachers for visually impaired, family members (parents and siblings) and affected children.ResultsThe literature review included 13 studies yielding 37 outcomes. Qualitative interviews provided 22 outcomes. After combining and refining similar items, the first round contained 23 outcomes and the second 46. At the consensus meeting, 5 attendees recommended 27 outcomes for inclusion in the CVI COS, of which 15 were ratified as most important, including 4 related to vision; 1 to family well-being; 1 to adults around the child being informed about CVI and the rest to the child's abilities to engage with people and surroundings.ConclusionsGood engagement from participants led to the development of a COS. Future research will be useful to identify the best ways to measure COS items and potentially to update this COS as more interventions for CVI are developed.Trial registration numberISRCTN13762177.

Project description:Background: The pupillary light reflex is weaker for stimuli presented inside as compared to outside absolute scotomas. Pupillograph perimetry could thus be an objective measure of impaired visual processing. However, the diagnostic accuracy in detecting scotomas has remained unclear. We quantitatively investigated the accuracy of a novel form of pupil perimetry. Methods: The new perimetry method, termed gaze-contingent flicker pupil perimetry, consists of the repetitive on, and off flickering of a bright disk (2 hz; 320 cd/m2; 4° diameter) on a gray background (160 cd/m2) for 4 seconds per stimulus location. The disk evokes continuous pupil oscillations at the same rate as its flicker frequency, and the oscillatory power of the pupil reflects visual sensitivity. We monocularly presented the disk at a total of 80 locations in the central visual field (max. 15°). The location of the flickering disk moved along with gaze to reduce confounds of eye movements (gaze-contingent paradigm). The test lasted ~5 min per eye and was performed on 7 patients with cerebral visual impairment (CVI), 8 patients with primary open angle glaucoma (age >45), and 14 healthy, age/gender-matched controls. Results: For all patients, pupil oscillation power (FFT based response amplitude to flicker) was significantly weaker when the flickering disk was presented in the impaired as compared to the intact visual field (CVI: 12%, AUC = 0.73; glaucoma: 9%, AUC = 0.63). Differences in power values between impaired and intact visual fields of patients were larger than differences in power values at corresponding locations in the visual fields of the healthy control group (CVI: AUC = 0.95; glaucoma: AUC = 0.87). Pupil sensitivity maps highlighted large field scotomas and indicated the type of visual field defect (VFD) as initially diagnosed with standard automated perimetry (SAP) fairly accurately in CVI patients but less accurately in glaucoma patients. Conclusions: We provide the first quantitative and objective evidence of flicker pupil perimetry's potential in detecting CVI-and glaucoma-induced VFDs. Gaze-contingent flicker pupil perimetry is a useful form of objective perimetry and results suggest it can be used to assess large VFDs with young CVI patients whom are unable to perform SAP.