Szlyk 2005.
| Study characteristics | ||
| Methods |
Substitutive intervention versus substitutive intervention Design: randomised cross‐over design Stratification: not stated Randomisation sequence: "randomly assigned" but method not given Comparisons: participants in Group 1 received Gottlieb prism during the first 3‐month phase of the study, and participants in Group 2 received Fresnel prisms during the first 3‐month phase of the study. Participants then crossed over to receive the other treatment. Allocation concealment: not stated Blinding: not stated Power calculation: not stated Intention‐to‐treat analysis: not stated Other recruitment details: not stated Patient and public involvement: not stated |
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| Participants |
Total study population: 10 participants. Withdrawals: no information (7 participants provided follow‐up data at 2 years ‐ 3 could not be contacted) Method of diagnosing VFD: not stated. Characteristics of population: participant details are listed in Table 6. Type and severity of visual problems: participant details are listed in Table 7. Inclusion criteria: stated "The patients were screened to include patients with only occipital lobe strokes". Participants described as having "Hemianopsia because of cerebral vascular accidents". All included participants were male, but unclear if this was an inclusion criterion. Exclusion criteria: not stated. Baseline comparison of treatment groups: yes The study included a mixed population. It was assumed that participants did not have neglect (as this is unlikely in occipital lesions). Method of diagnosing visual perceptual problems: not stated ‐ it was not stated whether the patients may have had visual neglect (although neglect is unlikely in occipital lesions) |
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| Interventions |
Group 1: Gottlieb Visual Field Awareness System (VFAS) (n = 5) Intervention type: substitution Intervention: Gottlieb VFAS prism Materials: 18.5 dioptre Gottlieb VFAS prism Where can materials be accessed? "Rekindle(R), Stone Mountain, GA, USA". Procedures: 18.5 dioptre Gottlieb VFAS prism drilled into one lens. Positioned just off pupil centre ‐ generally on the same eye as side of field loss, on same side as field loss, base out. Provided by: low‐vision specialist for laboratory and outdoor training, kinesiotherapist for on‐road training. Delivery: laboratory and out‐door training within university grounds, and on‐road (driving) training on a road course within a medical centre (Table 5). Regimen: training of 4 x 2 to 3‐hour sessions indoors with low vision specialist and 8 x 2‐hour outdoor sessions behind the wheel. The lenses were then worn for 3 months. Tailoring: not stated. Modification: not stated. Adherence: no information (whether prism was still worn at time of follow‐up was recorded as never/occasionally/frequently) Group 2: Fresnel prisms (n = 5) Intervention type: substitution Intervention: Press‐OnTM Fresnel 20 Diopter Prisms Materials: Press‐OnTM Fresnel 20 Diopter Prisms. Where can materials be accessed? "3M Health Care, St. Paul, MN, USA". Procedures: 20 dioptre press‐on Fresnel prisms attached to posterior surface of 1 spectacle lens. Positioned just off pupil centre ‐ generally on the same eye as side of field loss, on same side as field loss, base out. Provided by: low‐vision specialist for laboratory and outdoor training, kinesiotherapist for on‐road training. Delivery: laboratory and out‐door training within university grounds, and on‐road (driving) training on a road course within a medical centre (Table 5). Regimen: training of 4 x 2 to 3 hour sessions indoors with low‐vision specialist and 8 x 2‐hour outdoor sessions behind the wheel. The lenses were then worn for 3 months. Tailoring: not stated. Modification: not stated. Adherence: no information (whether prism was still worn at time of follow‐up was recorded as never/occasionally/frequently) |
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| Outcomes | See Table 8 Goldmann visual field Visual acuity Contrast sensitivity Lab assessment ‐ indoor functional assessment Outdoor function assessment Driving skills assessment ‐ indoor and on‐road Pyschophysical assessment ‐ attentional visual acuity ‐ attentional motion sensitivity Self‐report (satisfaction) Time points when outcomes were assessed: before and after each cross‐over. Continued use of devices assessed at 2‐year follow‐up |
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| Notes | 1. Data were presented after the cross‐over, for both groups combined ‐ no first phase data were available. 2. Stated: "For each assessment task for each individual in the test‐retest period, we computed the change in score from the initial baseline testing to the repeat baseline testing. We then averaged these change scores across subjects for each task". For each task If the change from baseline to training exceeded the test‐retest change it was scored as 'improved', if it was less than or equal it was scored as 'no change'. The sum of improved tasks across the test battery was then computed. |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Allocation concealment (selection bias) | Unclear risk | Stated "randomly assigned into one of two experimental groups" but no details of method provided |
| Blinding (performance bias and detection bias) All outcomes | Unclear risk | No details of blinding included |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | No incomplete data issues apparent, however, scores have been combined so it is difficult to tell if there are any missing outcomes. |
| Other bias | Low risk | No other cause of bias noted |
AB/BA: refers to order of interventions within cross‐over trial, where A and B denote different interventions and AB or BA the order of delivery ACS: alternating current stimulation ADL: activities of daily living ARV: area of residual vision AVT: audiovisual exploration training cd/m2: candela per square meter (standard unit of luminance) CNS: central nervous system CT: computerised tomography CVA: cerbrovascular accident EEG: electroencephalogram EQ‐5D:standardised EuroQol health‐related quality of life instrument FIM: Functional Independence Measure FT: flicker stimulation training HRP: high resolution perimetry HVFD: homonymous visual field defect IH‐CST: InSight Hemianopia ‐ Compensatory Scanning Training IVI: impact of visual impairment LCD: liquid crystal display (high definition monitor) LEDs: light emitting diodes LV‐VFQ: Low Vision ‐ Visual Function Questionnaire MMSE: Mini Mental State Examination MRC: Medical Research Council MRI: magnetic resonance imaging MT: moving text n: number NA: not applicable NEI‐VFQ: National Eye Institute Visual Function Questionnaire OT: occupational therapy PI: principal investigator QoL: quality of life RCT: randomised controlled trial RT: restitution therapy SD: standard deviation SF‐12: Short‐Form Health Survey T1/T2/T3/T4/T5: outcome asssessment timepoint 1, 2, 3, 4 or 5 TAP: Tubinger automated perimetry TBI: traumatic brain injury tDCS: transcranial direct current stimulation TL: tube luminescent VET: visual exploration training VFAS: visual field awareness system VFD: visual field defect VFQ‐25: visual functioning questionnaire VIS: Visual In Stroke (study name) VRT: vision restoration therapy VST: visual stimulation training WHOQOL‐BREF: wpm: words per minute