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Trial registered on ANZCTR


Registration number
ACTRN12618001111268
Ethics application status
Approved
Date submitted
23/06/2018
Date registered
4/07/2018
Date last updated
4/07/2018
Type of registration
Retrospectively registered

Titles & IDs
Public title
The prevalence of visual defects during early stages of stroke
Scientific title
The Epidemiology of Vision and Visual Field Defects after Acute stroke
Secondary ID [1] 294280 0
None
Universal Trial Number (UTN)
U1111-1212-6810
Trial acronym
VFAST
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Acute Ischemic Stroke 307535 0
Visual field defects 307536 0
Visual-Motor Capacity 308550 0
Visual Field Integrity 308551 0
Condition category
Condition code
Stroke 306617 306617 0 0
Ischaemic
Neurological 306618 306618 0 0
Neurodegenerative diseases
Eye 307571 307571 0 0
Diseases / disorders of the eye

Intervention/exposure
Study type
Observational
Patient registry
True
Target follow-up duration
12
Target follow-up type
Months
Description of intervention(s) / exposure
Vision and the visual processes occupy a large volume of brain yet stroke is diagnosed by its affects on motor processing. This is partly because to quantify the effects of stroke on visual capacity other than by screening tests, such as confrontation, is not easy especially in the early stages after acute stroke onset. At these stages patients are often debilitated or bedridden and can not undertake the complex, specialised testing needed for such evaluation.

We hope to address this limitation and better define the characteristics of acute stroke on vision and visual processing by using modern applications shown on portable tablet devices.

Our observational study was performed on one hundred and ten, consecutive patients admitted between June,2017-May,2018 to the Neurology Ward at Sunshine Hospital, Melbourne, and who were diagnosed as having suffered a stroke by conventional clinical diagnostic methods. All patients were bed-bound and were requested within 1 week after admission to volunteer for vision testing using two iPad applications “Melbourne Rapid Field” (MRF) App (visual acuity (threshold spatial vision), threshold visual field) and the "UNSW L-R Eye-Hand Coordination"App (visuo-motor capacity). Testing was performed at the bedside of stroke patients who volunteered to participate in this study consistent with our ethics clearance. Their visual acuity, visual field extent and visuo-motor skills were followed up at 3, 6 and 12 months to monitor recovery. The health care of all patients is being administered based on standard clinical practice and the vision testing outcomes will not impact on this management.
Intervention code [1] 300977 0
Not applicable
Comparator / control treatment
Thirty age-similar controls were recruited as volunteers following an eye examination at a private optometry practice. They were tested using the same suite of vision tests (visual acuity, visual field and visual motor skills) in the optometry practice.

All recruitment complied with our HEC approval (HREC/16/WH/1). The control participants had no history of ocular, cognitive or neurological conditions that could be expected to impact on their vision and testing for visual fields or visual acuity.
Control group
Active

Outcomes
Primary outcome [1] 306257 0
Visual Field Integrity using Mean Deviation (Mean of Threshold Deviation in dB) for the acute stroke group and its comparison to the control patients.

Instrument : Melbourne Rapid Fields (MRF) Application.
The Melbourne Rapid Fields-Neural app (MRF-neural) has been developed by GLANCE Optical Pty Ltd, Melbourne, Australia to measure thresholds across 21 degrees of the visual field using a large screen (12.9 inch) iPad Pro tablet (Apple, Cupertino, CA). The test is conducted at 33 cm with the patient wearing their habitual reading glasses. With central fixation, the 12.9-inch iPad screen subtends 22° x 17° (H x V) at the usual viewing distance of 33 cm (13 inches). The test pattern used by MRF-neural is a reduced and modified 24-2 Humphrey grid (clinical standard) that shows spots out to 21 degrees (instead of 27 degrees) with 4 extra spots added to central locations (0.8 degrees) to test foveal thresholds. Spot size has been scaled across the visual field to allow for the tangent effect of a planar screen and to produce constant spatial and probability summation which gives rise to a fixed threshold (30 dB) at all locations.

Patients respond to the presence of a spot by tapping the space bar on the keyboard connected to the tablet (NB the test can be performed without a keyboard). Thresholds are estimated using a Bayesian thresholding logic (Vingrys et al. Translational Vision Science & Technology (TVST), 2016). Reliability indices (false positive, negative and fixation loss) are polled during testing.

Voice commands can be generated by the tablet to instruct the patient on how to perform the test. These were used with our normal controls but at the bedside the voice over was turned off as we found operator input was faster and more flexible in performing the test with stroke patients. The design principles and procedural aspects of performing the visual field have been detailed elsewhere by Vingrys et al (TVST, 2016).

Timepoint [1] 306257 0
Within one week after the onset of stroke for acute stroke.
Following a routine eye examination for controls
Primary outcome [2] 306258 0
We will also measure the time taken undertaking a visuo-motor hand eye coordination task using UNSW L-R Hand-Eye Coordination App ( https:// newsroom.unsw.edu.au/news/science-tech/new-app-assess-eye-hand-coordination). Here the patient has to trace out 3 images on the ipad using an ipad pencil.

The time taken and number of errors created while tracing the images by stroke cases will be compared to the control group.This will provide a measure of the patient's fine motor skills during the acute stage of a stroke and determine whether these improve with time.
Timepoint [2] 306258 0
Within one week after the onset of the stroke
Following a routine eye examination for controls
Primary outcome [3] 306259 0
Visual Acuity will also be determined with and without luminance Noise using the MRF tablet application in patients with an Acute Stroke. Visual acuity to high contrast optotypes will be measured to ascertain whether patients meet the legal requirement for driving in Victoria following an episode of stroke.

Acuity will also be determined for optotypes immersed in noise as these are sensitive to abnormal brain processing such as occurs in amblyopia (Pelli et al. Journal of Vision. 2004) and might prove useful in cases of stroke where an elevated intrinsic level of noise is highly likely.
Timepoint [3] 306259 0
Within one week since the onset of the stroke
Following a routine eye examination for controls
Secondary outcome [1] 347995 0
The Visual Field Recovery
The longitudinal visual field recovery will be quantified using foveal threhsolds ,mean deviation of visual fields and quantified areas of visual field loss.
Timepoint [1] 347995 0
3-months post initial assessment
Secondary outcome [2] 347997 0
Fundus Photography

Given the common embryology of retinal neural and vascular beds with those of the cortex we will obtain fundus photographs of the retina for enface images to observe the retinal vascular status during the initial phase of an ischemic event in comparison to the visual fields and MRI/CT scans,
Timepoint [2] 347997 0
3 months post-initial assessment
Secondary outcome [3] 348661 0
Optical Coherence Tomography ( OCT)

Precise retinal cross-sectional data will be collected using optical coherence topography (resolution of 7-9 micron) from acute stroke patients. The changes in retina neural and vascular tissues will be compared with the quantified visual field changes and the brain MRI/CT scans during the patient's recovery period post stroke.
Timepoint [3] 348661 0
6 months post-initial assessment

Eligibility
Key inclusion criteria
Any patient admitted with a clinical diagnosis of an ischemic acute stroke (within a week since the onset of the stroke) with no history of ocular, cognitive or neurological conditions that could be expected to impact on their visual acuity, visual fields or visuo-motor capacity.

All controls will have an age-similar profile to our stroke group and will have normal vision, eye health, brain health and systemic health. They will meet our exclusion criteria.
Minimum age
30 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Patients with:
1. medical record of co-existing ocular conditions such as glaucoma, macular degeneration, diabetes, cataracts or other causes of monocular vision loss (<6/9)
2. Severe cognitive or physical impairment that limits performance on tests
3. Inadequate English to understand the instructions for the testing
4. Poor reliably (errors >50%) on the visual fields
5. Acute stroke resultant to a heammorragic cause
Same exclusion criteria apply to the controls

Study design
Purpose
Natural history
Duration
Longitudinal
Selection
Defined population
Timing
Prospective
Statistical methods / analysis
Sample size has been calaculated from past studies which have recruited 50-100 participants for similar tasks. Moreover, given the variabiity reported for the MRF indices a sample size of 50 will be able to expose moderate to small effect sizes.

The Data will be analysed for:
1. The mean deviation from control of the patient's visual field
2. The foveal threshold
3. Visual Acuity to high contrast targets and those immersed in noise,
4. Visuo-motor capacity in the hand eye coordination task.

From previous studies we anticipate a large spread in our stroke group which will mean that parametric testing can not be applied. We will test for normality in the data and for homogeneity of variance and in its absence will adopt a Mann-Whitney U test for comparison of mid-points with an alpha of 0.05.

Data concordance will be established after raw scores had been converted into z-scores using a Person product moment correlation coefficient.

Diagnostic accuracy will be established using ROC analysis.

Recruitment
Recruitment status
Active, not recruiting
Date of first participant enrolment
Anticipated
Actual
2/07/2017
Date of last participant enrolment
Anticipated
Actual
4/05/2018
Date of last data collection
Anticipated
31/12/2019
Actual
Sample size
Target
50
Accrual to date
Final
60
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 11124 0
Sunshine Hospital - St Albans
Recruitment postcode(s) [1] 22940 0
3021 - St Albans

Funding & Sponsors
Funding source category [1] 298916 0
Commercial sector/Industry
Name [1] 298916 0
Glance Optical Pty Ltd
Country [1] 298916 0
Australia
Primary sponsor type
University
Name
The La Trobe University,Melbourne
Address
Room 122, Biological Sciences 2 Building.
La Trobe Univeristy,
Plenty Rd & Kingsbury Dr, Bundoora VIC 3086
Country
Australia
Secondary sponsor category [1] 298129 0
Hospital
Name [1] 298129 0
The Sunshine Hospital,Western Health,Melbourne
Address [1] 298129 0
Western Health
Department of Neurology
176, Furlong Road
St Albans Vic 3021
Australia
Country [1] 298129 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 299858 0
Western Health Low Risk Human Research Ethics Panel
Ethics committee address [1] 299858 0
Western Health Office for Research
Level 3 Western Centre for Health, Research & Education (CHRE)
Sunshine Hospital
Furlong Road
St Albans VIC 3021
Ethics committee country [1] 299858 0
Australia
Date submitted for ethics approval [1] 299858 0
06/09/2016
Approval date [1] 299858 0
22/11/2016
Ethics approval number [1] 299858 0
HREC/16/WH/1

Summary
Brief summary
Impaired motor function and cognitive confusion are the most common diagnostic symptoms associated with "stroke". Few acute clinical investigations of visual function are conducted even though far greater volumes of cortical and subcortical regions of the brain are directly involved with visual functions than with motor function. Van Essen et al (1984) first highlighted the vast number of visual areas and volume of cortex attributed to visual sensory processing, visual attention, visuo-motor functions and visually driven emotional processing. Furthermore the eye and the brain share similar embryonically derived vascular tissues and blood flow making vision defect a likely companion to a brain blood disorder (stroke).

Over the last decade Rowe et al (2009), Spotfforth et al (2017) and Quinn et al (2018) have described significant persistent visual deficits following stroke. Of those affected common visual deficits up to a year later include visual field loss (hemianopia, quadrantanopia) ,perceptual disorders (visual inattention/neglect) and eye movement disorders. Rowe et al (2009) also noted the large proportion of ocular alignment deficits co-morbid with visual field defects. Most recently Quinn et al (2018) highlighted the incidence of visual field deficits with coexisting visual neglect in post stroke survivors.

Hemifield neglect has long been known as a perceptual deficit sometimes associated with stroke although when tested it is most often tested manually by line bisection or star cancellation even though stroke itself is usually defined by motor impairments. Application of sophisticated visual field analyzers such as the Humphrey have seldom been utilized in hospitalized stroke patients given that most cases involve elderly patients limited in mobility and who suffer motor impairment for at least 24 hours.

Thus the purpose of this study was to consider whether visual field losses can be identified and quantified in the acute stages of stroke using an ipad based bed side perimetry app, The Melbourne Rapid Fields (MRF), developed to measure visual acuity and visual field integrity. The neuroanatomical site of lesion was also considered in relation to field deficits to evalute the clinical and radiographic imaging patterns with the patient’s visual acuity and visual field intergrity.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 81790 0
Prof Sheila Crewther
Address 81790 0
La Trobe University
Room 122,Biological Sciences 2 Building,
College of Science, Health and Engineering,
Department of Psychology and Counselling
Plenty Rd & Kingsbury Drive,
Bundoora VIC 3086
Country 81790 0
Australia
Phone 81790 0
+61394792290
Fax 81790 0
+61394791956
Email 81790 0
[email protected]
Contact person for public queries
Name 81791 0
Tissa Wijeratne
Address 81791 0
Director,Department of Neurology and Stroke Services,
Level 3,WCHRE Building,
Sunshine Hospital,
176,Furlong Rd,St Albans ,
Vic 3021
Country 81791 0
Australia
Phone 81791 0
+61383456766
Fax 81791 0
+61383456882
Email 81791 0
[email protected]
Contact person for scientific queries
Name 81792 0
Sheila Crewther
Address 81792 0
La Trobe University
Room 122,Biological Sciences 2 Building,
College of Science, Health and Engineering,
Department of Psychology and Counselling
Plenty Rd & Kingsbury Drive,
Bundoora VIC 3086
Country 81792 0
Australia
Phone 81792 0
+61394792290
Fax 81792 0
+61394791956
Email 81792 0
[email protected]

No information has been provided regarding IPD availability


What supporting documents are/will be available?

Current supporting documents:


Updated to:
Doc. No.TypeCitationLinkEmailOther DetailsAttachment
23609Ethical approval    374683-(Uploaded-15-06-2020-00-12-51)-Study-related document.docx
23610Informed consent form  [email protected] 374683-(Uploaded-15-06-2020-01-31-49)-Study-related document.HEIC

Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
SourceTitleYear of PublicationDOI
EmbaseAcquired Visual Deficits Independent of Lesion Site in Acute Stroke.2020https://dx.doi.org/10.3389/fneur.2020.00705
Dimensions AIVision and Visuomotor Performance Following Acute Ischemic Stroke2022https://doi.org/10.3389/fneur.2022.757431
N.B. These documents automatically identified may not have been verified by the study sponsor.