Vision Disorders, Vision, Low
Conditions
Keywords
viewing strategies, (cerebral) visual impairment, visual rehabilitation, reading strategies, visual search strategies
Brief summary
Viewing strategies are strategies used to process visual Information. Many children with visual impairment seem to lack systematic viewing strategies. However, it is unknown how viewing strategies differ between children with normal vision and children with (cerebral) visual impairment. In addition, viewing strategy training is often adopted in clinical practice, but till date there is no scientific evidence about effectiveness of this approach. The current project has two goals: (1) to measure viewing strategies used by children with normal vision, children with ocular visual impairment and children with CVI, and (2) to evaluate whether training viewing strategies results in more efficiënt visual Information processing.
Interventions
BEHAVIORALViewing strategy training
Children receive a visual training of viewing strategies (six weeks, 2 times a week, 30 minutes). During the training, children are instructed to use specific viewing strategies (looking in a structured direction which fits the task at hand, zooming in and out / change of visual selective attentional field, visual discrimination). The verbal instructions and exercises are protocol-based. A textbook is used to describe the reactions of the children during training.
Sponsors
Radboud University, Behavioural Science Institute, Nijmegen, The Netherlands
Royal Dutch Visio
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
For the first phase of the study, we aim to include 48 children aged 5-12 years for each group (i.e. normal Vision, ocular visual impairment, cerebral visual impairment). For the second phase of the study 60 children with visual impairment aged 5-9 years will be included (ocular impairment: n=30, cerebral visual impairment: n=30). In the second phase of the project, children receive a visual training of viewing strategies (six weeks, 2 times a week, 30 minutes). During the training, children are instructed to use specific viewing strategies (looking in a structured direction which fits the task at hand, zooming in and out / change of visual selective attentional field, visual discrimination). The verbal instructions and exercises are protocol based. A textbook is used to describe the reactions of the children during training.
Eligibility
Sex/Gender
ALL
Age
5 Years to 12 Years
Healthy volunteers
Yes
Inclusion criteria
typically developing children with normal vision: * Age 5-12 years * linear distant visual acuity of 0.1 logMAR or better * Verbal IQ above 70 * Absence of developmental disorders or psychiatric problems like ASS or AD(H)D Inclusion criteria for children with ocular visual impairment: * Age 5-12 years * Children with linear distance visual acuity better \<=1.3logMAR and \>0.1 logMAR * Intact central visual field (at least \> 30 degrees) * Children with a verbal IQ above 70 * Absence of developmental disorders or psychiatric problems like ASS or AD(H)D Inclusion criteria for children with cerebral visual impairment: * Age 5-12 years * Linear distance visual acuity \<=0.3 logMAR * Having the diagnosis CVI (verified by ophthalmologists) * Children with a verbal IQ above 70 * Absence of psychiatric problems like ASS or AD(H)D Additional inclusion criterion for study 2 (evaluating training effectiveness): children with (cerebral) visual impairment should have an indication for viewing strategy training. Training should not be indicated if children have no problems performing academic tasks (i.e. when speed and accuracy of visual processing is within the normal range). The age range for study 2 is 5-9 years.
Exclusion criteria
* Children with VI: linear near visual acuity \>1.0 logMAR * Children with visual field defect \< 30 degrees * Children with a verbal IQ below 70 * Children who attended a form of vision training in the past two years * Children with psychiatric problems like ASS or AD(H)D * Auditory impairment or language impairments * Major life events during training
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in average distance between fixation points during conjunction search (EB-VSA) after training | Group A: Day 0, Month 2, Month 8; Group B: Day 0, Month 2, Month 4 | Average distance between fixation points using Radner reading test and conjunction search |
| Changes in visual search accuracy after training | Group A: Day 0, Month 2, Month 8; group B: Day 0, Month 2, Month 4 | Accuracy during conjunction search |
| Changes in visual search speed after training | Group A: Day 0, Month 2, Month 8; Group B: Day 0, Month 2, Month 4 | Speed during conjunction search |
| Changes in saccade amplitudes during reading and visual search after training | Group A: Day 0, Month 2, Month 8; Group B: Day 0, Month 2, Month 4 | Saccade amplitudes measured using Radner reading test and conjunction search |
| Changes in fixation duration during reading and search after training | Group A: Day 0, Month 2, Month 8; Group B: Day 0, Month 2, Month 4 | Fixation durations measured using Radner reading test and conjunction search |
| Changes in reading accuracy after viewing strategy training | Group A: Day 0, Month 2, Month 8; group B: Day 0, Month 2, Month 4 | Radner reading test |
| Changes in reading speed after viewing strategy training | Group A: Day 0, Month 2, Month 8; group B: Day 0, Month 2, Month 4 | Radner reading test |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Changes in local visual selective attention after training | Group A: Day 0, Month 2, Month 8; Group B: Day 0, Month 2, Month 4 | TEA-Ch Speurtocht (total number of symbols found in 1 minute) |
| Changes in global visual selective attention after training | Group A: Day 0, Month 2, Month 8; Group B: Day 0, Month 2, Month 4 | Gestalt Closure (Kaufman-ABC), number of correct answers |
| Changes in visual identification speed after training | Group A: Day 0, Month 2, Month 8; Group B: Day 0, Month 2, Month 4 | 'DST-Plaatjes Benoemen', number of pictures correctly named within 1 minute |
| Changes in WISC-V visual processing speed index (VSI) after training | Group A: Day 0, Month 2, Month 8; Group B: Day 0, Month 2, Month 4 | WISC-IV visual processing speed index |
Countries
Netherlands
Contacts
Primary ContactBianca Huurneman, PhD
Outcome results
None listed