Visual Impairment Screening Assessment (VISA)

Purpose

The Visual Impairment ScreeningTesting for disease in people without symptoms.
Assessment (VISA) is designed to identify visual impairment following strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More, to allow referral for specialist visual assessment. The VISA was developed by the VISION research unit, University of Liverpool.

In-Depth Review

Purpose of the measure

The Visual Impairment ScreeningTesting for disease in people without symptoms.
Assessment (VISA) is designed to identify visual impairment following strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. More. The VISA screens for common visual impairments following strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. More including impaired central vision, eye movement problems, visual field deficits and visual inattention. The VISA can be used to detect ocular signs separate from reporting of vision symptoms.

Available versions

The VISA was developed from a review of strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. More and vision research studies, and in collaboration with a panel of strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. More specialists and patients, and validated in a clinical study.

The VISA is available in print and as a software app.

Features of the measure

 Items:

The VISA comprises five sections:

1. Case history – to screen for visual symptoms and observed signs – in person or by proxy.
2. Visual acuity – to screen central vision at near (33cm) and distance (3m) using LogMAR (Logarithm of the Minimum Angle of Resolution) or Grating acuity; monocular or binocular depending on the ability of the patient.
3. Ocular alignment and movement – to screen presence/absence of strabismus and eye movement problems.
4. Visual field* – to screen peripheral and central field of vision by a guided confrontation method.
5. Visual perception – to screen for visual inattention/neglect using (i) line bisection task, (ii) cancellation task and (iii) clock drawing assessment.

*Visual field assessment – print version: confrontation follows a typical method with the clinician seated directly opposite the patient at a distance of 1m and following stages that involve the patient indicating when a 10mm red target is seen in the periphery of their vision, finger counting in each quadrant of the visual field and comparison of examiner facial features.

*Visual field assessment – app version: a kinetic visual field assessment is undertaken at a test distance of 30cm and a screen width of 24.6cm, allowing an assessment of the 40degree visual field. The patient is asked to fixate a static fixation point in the corner of the screen while a stimulus moves from the other edges. They are asked to tap the tablet screen when the stimulus is seen. This is repeated with the fixation target positioned at all four corners of the screen.

Scoring:

Administration of the VISA screeningTesting for disease in people without symptoms.
tool does not result in a score. Rather, the tool serves as a guide for referral for specialist visual assessment as per observations outlined in the VISA Instructions for Use booklet.

What to consider before beginning:

The VISA screens for common forms of visual impairment that occur from brain injury but does not screen for all possible visual impairments. As such a negative screen does not rule out the presence of visual impairment.

The individual may not be able to complete all sections of the VISA at one time (e.g. due to fatigue, cognitive difficulties, communication difficulties). In this instance the VISA can be completed over several visits.

The individual is permitted to wear glasses (if required) for some assessment items.

The VISA must be performed in good lighting conditions.

Time:

The VISA takes approximately 10 minutes to administer, but longer if multiple visual problems and if associated cognitive issues.

Equipment:

Equipment is outlined in the VISA Instructions for Use booklet and includes:

• Pen torch
• Occlusive tape
• 10mm red target
• +3.00 power reading glasses
• 3 metre string/tape measure
• Matching card for visual acuity check
• Visual attention worksheets
• Pencil
• VISA recording sheet

Client suitability

Can be used with:

Individuals with acute strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. More

Individuals with community/cognitive difficulties who are unable to comply with any letter test – The assessor can use a grating chart that uses a preferential looking technique.

StrokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. More patients have reported that it is easier to respond using the touch screen (VISA app) than traditional pen and paper tasks when using their non-dominant hand.

Should not be used with:

The VISA may not be completed in full due to cognitive difficulty or fatigue. Information regarding the individual’s vision history can be gathered from reliable family members. VISA app cannot be used on small devices such as iPad Mini or smartphones.

Languages of the measure

English – print and app
Dutch – print
Norwegian – print

Requests for translations are welcome. The VISA researchers will work closely with translators using the WHO-recommended translation process.

Summary

What does the tool measure?	Visual impairment
What types of clients can the tool be used for?	The Visual Impairment ScreeningTesting for disease in people without symptoms. Assessment can be used with individuals with strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More.
Is this a screeningTesting for disease in people without symptoms. or assessment tool?	ScreeningTesting for disease in people without symptoms.
Time to administer	10 minutes – may be longer if multiple visual problems
ICF Domain	Impairment
Versions	There is a print version and an app version of the VISA.
Languages	English Dutch Norwegian
Measurement Properties
ReliabilityReliability can be defined in a variety of ways. It is generally understood to be the extent to which a measure is stable or consistent and produces similar results when administered repeatedly. A more technical definition of reliability is that it is the proportion of “true” variation in scores derived from a particular measure. The total variation in any given score may be thought of as consisting of true variation (the variation of interest) and error variation (which includes random error as well as systematic error). True variation is that variation which actually reflects differences in the construct under study, e.g., the actual severity of neurological impairment. Random error refers to “noise” in the scores due to chance factors, e.g., a loud noise distracts a patient thus affecting his performance, which, in turn, affects the score. Systematic error refers to bias that influences scores in a specific direction in a fairly consistent way, e.g., one neurologist in a group tends to rate all patients as being more disabled than do other neurologists in the group. There are many variations on the measurement of reliability including alternate-forms, internal consistency , inter-rater agreement , intra-rater agreement , and test-retest .	Internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. More: No studies have reported on internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. More of the VISA. Test-retest: No studies have reported on test-retest reliabilityA way of estimating the reliability of a scale in which individuals are administered the same scale on two different occasions and then the two scores are assessed for consistency. This method of evaluating reliability is appropriate only if the phenomenon that the scale measures is known to be stable over the interval between assessments. If the phenomenon being measured fluctuates substantially over time, then the test-retest paradigm may significantly underestimate reliability. In using test-retest reliability, the investigator needs to take into account the possibility of practice effects, which can artificially inflate the estimate of reliability (National Multiple Sclerosis Society). of the VISA. Intra-rater: No studies have reported on intra-rater reliabilityThis is a type of reliability assessment in which the same assessment is completed by the same rater on two or more occasions. These different ratings are then compared, generally by means of correlation. Since the same individual is completing both assessments, the rater’s subsequent ratings are contaminated by knowledge of earlier ratings. of the VISA. Inter-rater: Two studies reported substantial agreement on inter-rater reliabilityA method of measuring reliability . Inter-rater reliability determines the extent to which two or more raters obtain the same result when using the same instrument to measure a concept. evaluation of the VISA.
ValidityThe degree to which an assessment measures what it is supposed to measure.	Content: Pilot validation of the VISA was conducted in collaboration with medical students (naïve screeners) and orthoptists. Criterion: Concurrent: No studies have reported on concurrent validityTo validate a new measure, the results of the measure are compared to the results of the gold standard obtained at approximately the same point in time (concurrently), so they both reflect the same construct. This approach is useful in situations when a new or untested tool is potentially more efficient, easier to administer, more practical, or safer than another more established method and is being proposed as an alternative instrument. See also “gold standard.” of the VISA. Predictive: No studies have reported on predictive validityA form of criterion validity that examines a measure’s ability to predict some subsequent event. Example: can the Berg Balance Scale predict falls over the following 6 weeks? The criterion standard in this example would be whether the patient fell over the next 6 weeks. of the VISA. Construct: Convergent/Discriminant: Two studies reported poor to substantial test component agreement between the VISA screen and specialist vision assessments. One study reported perfect agreement between kinetic visual field test using the VISA app and formal perimetry. Known Groups: No studies have reported on known group validityThe degree to which an assessment measures what it is supposed to measure. of the VISA.
Floor/Ceiling Effects	No studies have reported on floor/ceiling effects of the VISA. Two studies noted false positives and false negatives on individual components of the tool.
Does the tool detect change?	No studies have reported on responsivenessThe ability of an instrument to detect clinically important change over time. of the VISA.
Acceptability	Two studies reported on acceptability of the VISA, from a sample of strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More patients and orthoptists.
Feasibility	The VISA is suitable for administration in various settings. The VISA requires minimal specialist equipment or training. One study noted that the VISA is time-intensive when used in the hyperacute stage with unwell patients.
How to obtain the tool?	The VISA is available in print or as an app (Medicines and Healthcare products Regulatory Agency regulatory approved): https://www.liverpool.ac.uk/population-health/research/groups/vision/visa/? Further information regarding the tool and administration guidelines can be found here: https://youtu.be/-s6i–PfXNY

Psychometric Properties

Overview

The Visual Impairment ScreeningTesting for disease in people without symptoms.
Assessment (VISA) was developed by the VISION Research Unit, University of Liverpool in consultation with an expert panel of stroke-specialist clinical orthoptists, strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. More research orthoptists, stroke-specialist occupational therapists and neuro-ophthalmologists (Rowe et al., 2018). A literature search was conducted to identify all relevant publications on the psychometric properties of the VISA pertinent to use with participants following strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. More. Two studies were identified.

Floor/Ceiling Effects

Floor/ceiling effects of the VISA have not been measured.

Reliability

Internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. More:
Internal consistencyA method of measuring reliability . Internal consistency reflects the extent to which items of a test measure various aspects of the same characteristic and nothing else. Internal consistency coefficients can take on values from 0 to 1. Higher values represent higher levels of internal consistency. More of the VISA has not been measured.

Test-retest:
Test-retest reliabilityA way of estimating the reliability of a scale in which individuals are administered the same scale on two different occasions and then the two scores are assessed for consistency. This method of evaluating reliability is appropriate only if the phenomenon that the scale measures is known to be stable over the interval between assessments. If the phenomenon being measured fluctuates substantially over time, then the test-retest paradigm may significantly underestimate reliability. In using test-retest reliability, the investigator needs to take into account the possibility of practice effects, which can artificially inflate the estimate of reliability (National Multiple Sclerosis Society).
of the VISA has not been measured.

Intra-rater:
Intra-rater reliabilityThis is a type of reliability assessment in which the same assessment is completed by the same rater on two or more occasions. These different ratings are then compared, generally by means of correlation. Since the same individual is completing both assessments, the rater’s subsequent ratings are contaminated by knowledge of earlier ratings.
of the VISA has not been measured.

Inter-rater :
Rowe et al. (2018) examined inter-rater agreement of the VISA in a sample of 116 individuals with strokeAlso called a "brain attack" and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a "schemic stroke", or the formation of a blood clot in a vessel supplying blood to the brain. More, whereby each individual underwent two vision assessments: a specialist vision assessment performed by orthoptists/ophthalmologists (n=5) and the VISA screeningTesting for disease in people without symptoms.
assessment, completed by medical students (n=2) and orthoptists (n=4). Agreement regarding need to make a referral to specialist eye services due to visual impairment was measured using kappa values. Overall agreement was substantial (k=0.736, 95% CI 0.602 to 0.870). As expected, a higher rate of false positives and false negatives were found among screeners naïve to vision testing (n=2 medical students) vs. experienced screeners (n=5 orthoptists/ophthalmologists).

Rowe et al. (2020) examined inter-rater agreement of the VISA in a sample of 221 individuals with stroke, whereby each individual underwent two vision assessments: a specialist vision assessment performed by orthoptists/ophthalmologists and the VISA screeningTesting for disease in people without symptoms.
assessment. The outcome was the presence/absence of visual impairment*. Agreement was substantial for the VISA print (k=0.648, 95% CI 0.424 to 0.872) and for the VISA app (k= 0.690, 95% CI 0.528 to 0.851).

*Presence/absence of visual impairment was defined as one or more of: reduced distance vision <0.2 logMAR, reduced near vision <0.3 logMAR (equivalent to N6), deviated eye position, eye movement abnormality (incomplete eye rotations in any position of gaze), visual field loss, visual inattention with displaced line bisection, <42 score on cancellation task and/or incomplete/displaced clock drawing.

Validity

Content:

Pilot validation of the VISA was conducted in collaboration with medical students (naïve screeners) and orthoptists; independent specialist vison assessment was performed by orthoptists/ophthalmologists. Written and verbal feedback was gathered from screeners and a thematic approach to analysis of qualitative date was used. A modified grounded theory approach was adopted to revise themes iteratively as analyses continued (Rowe et al., 2018).

Criterion:

Concurrent:
Concurrent validityTo validate a new measure, the results of the measure are compared to the results of the gold standard obtained at approximately the same point in time (concurrently), so they both reflect the same construct. This approach is useful in situations when a new or untested tool is potentially more efficient, easier to administer, more practical, or safer than another more established method and is being proposed as an alternative instrument. See also “gold standard.”
of the VISA has not been measured.

Predictive:
Predictive validityA form of criterion validity that examines a measure’s ability to predict some subsequent event. Example: can the Berg Balance Scale predict falls over the following 6 weeks? The criterion standard in this example would be whether the patient fell over the next 6 weeks.
of the VISA has not been measured.

Construct

Convergent/Discriminant :
Rowe et al. (2018) examined test component agreement between the VISA screen and specialist vision assessments (visual acuity, ocular alignment and movement, visual fields, visual perception) in a sample of 116 individuals with strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More, using kappa values. Agreement of items ranged from poor to substantial:

• Near visual acuity (k=0.682, CI 0.543 to 0.820; 10 false negatives, 7 false positives)
• Distance visual acuity (k=0.785, CI 0.665 to 0.904; 8 false negatives, 3 false positives)
• Ocular alignment (k=0.585, CI 0.221 to 0.949; 4 false negatives, 0 false positives)
• Ocular motility (k=0.120, CI -0.071 to 0.311; 21 false negatives, 6 false positives)
• Visual fields (k=0.741, CI 0.599 to 0.884; 3 false negatives, 8 false positives)
• Visual inattention (k=0.361, CI 0.144 to 0.578; 1 false negative, 16 false positives).

Rowe et al. (2020) examined test component agreement of the VISA print and VISA app screeningTesting for disease in people without symptoms.
assessments with specialist vision assessments (visual acuity, ocular alignment and movement, visual fields, visual perception) in a sample of 221 individuals with strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More, using kappa values. Agreement of individual components between VISA print and orthoptic vision assessment ranged from poor to moderate:

• Near visual acuity (k=0.236, CI 0.045 to 0.427; 23 false negatives, 12 false positives)
• Distance visual acuity (k=0.565, CI 0.405 to 0.725; 9 false negatives, 13 false positives)
• Ocular alignment (k=0.388, CI 0.110 to 0.667; 5 false negatives, 7 false positives)
• Ocular motility (k=0.365, CI 0.181 to 0.553; 10 false negatives, 19 false positives)
• Visual fields (k=0.504, CI 0.339 to 0.668; 7 false negatives, 18 false positives)
• Visual inattention (k=0.500, CI 0.340 to 0.659; 7 false negative, 21 false positives).

Agreement of individual components between VISA app and orthoptic vision assessment ranged from fair to substantial:

• Near visual acuity (k=0.416, CI 00.227 to 0.605; 19 false negatives, 3 false positives)
• Distance visual acuity (k=0.783, CI 0.656 to 0.910; 6 false negatives, 4 false positives)
• Visual fields (k=0.701, CI 0.564 to 0.838, 3 false negatives, 12 false positives)
• Visual inattention (k=0.323, CI 0.108 to 0.538; 6 false negatives, 16 false positives).

Rowe et al. (2020) examined agreement between kinetic visual field test using the VISA app and formal perimetry using the binocular Esterman programme with 25 individuals with strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More, using kappa values. There was perfect agreement (k=1.00) between measures.

Known Group:
Known group validityThe degree to which an assessment measures what it is supposed to measure.
of the VISA has not been measured.

Responsiveness

SensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also “Specificity.”
& SpecificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
:
Rowe et al. (2018) examined sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also “Specificity.”
and specificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
of the VISA in a sample of 89 individuals with strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More by comparison with a binary assessment of the presence/absence of visual impairment (low vision <0.2 logMAR, visual field loss, eye movement abnormality, visual perception abnormality). SensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also “Specificity.”
was defined as the proportion of patients with visual impairment who are correctly identified by the screener; sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also “Specificity.”
of 90.24% was found. SpecificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
was defined as the proportion of patients without visual impairment who were correctly identified by the screener; specificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
of 85.29% was found. The positive and negative predictive values were 93.67% and 78.36% (respectively).

Rowe et al. (2018) also compared sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also “Specificity.”
and specificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
of the VISA when performed by naïve screeners (n=2 medical students) vs. experienced screeners (n=5 orthoptists/ophthalmologists). When used by a naïve screener the VISA screen had a sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also “Specificity.”
of 82.93% and specificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
of 80.95%; when used by an experienced screener the VISA screen had a sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also “Specificity.”
of 97.56% and specificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
of 92.31%.

Rowe et al. (2020) examined sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also “Specificity.”
and specificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
of the VISA in a sample of 221 individuals with strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More. SensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also “Specificity.”
was estimated as the proportion of patients with visual impairment as diagnosed by the gold-standard clinical examination, which are correctly identified by the screener; sensitivitySensitivity refers to the probability that a diagnostic technique will detect a particular disease or condition when it does indeed exist in a patient (National Multiple Sclerosis Society). See also “Specificity.”
of the VISA print and VISA app was 97.67% and 88.31% (respectively). SpecificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
was estimated as the proportion of patients without visual impairment that are correctly identified by the screener; specificitySpecificity refers to the probability that a diagnostic technique will indicate a negative test result when the condition is absent (true negative).
of the VISA print and VISA app was 60.00% and 86.96% (respectively). The positive and negative predictive values of the VISA print were 93.33% and 81.82%. The positive and negative predictive values of the VISA app were 95.77% and 68.97% (respectively).

Acceptability:
Rowe et al. (2018) examined acceptability of the VISA tool through process evaluation of written feedback and interviews with strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More patients and strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More specialists. Qualitative data regarding number of items, clarity of questions, time and ease of testing was gathered and analysed using a thematic approach, and a modified grounded theory approach was subsequently used to revise themes as interviews and analyses progressed.

Rowe et al. (2020) examined acceptability of the VISA tool through process evaluation of clinician feedback sheets and strokeAlso called a “brain attack” and happens when brain cells die because of inadequate blood flow. 20% of cases are a hemorrhage in the brain caused by a rupture or leakage from a blood vessel. 80% of cases are also know as a “schemic stroke”, or the formation of a blood clot in a vessel supplying blood to the brain. More patients interviews. Qualitative feedback regarding duration of assessment, presentation of tests on the VISA app and referral guides were received.

References

Rowe, F.J., Hepworth, L.R., Hanna, K.L., & Howard, C. (2018). Visual Impairment Screening Assessment (VISA) tool: pilot validation. BMJ Open, 8:e020562. doi:10.1136/bmjopen-2017-020562

Rowe, F.J., Hepworth, L., Howard, C., Bruce, A., Smerdon, V., Payne, T., Jimmieson, P., & Burnside, G. (2020). Vision Screening Assessment (VISA) tool: diagnostic accuracy validation of a novel screening tool in detecting visual impairment among stroke survivors. BMJ Open, 10:e033639. doi:10.1136/bmjopen-2019-033639

See the measure

How to obtain the Visual Impairment ScreeningTesting for disease in people without symptoms.
Assessment (VISA)

The VISA is available in print or as an app (Medicines and Healthcare products Regulatory Agency regulatory approved).

The VISA Instructions for Use booklet can be found here: https://www.liverpool.ac.uk/population-health/research/groups/vision/visa/?

The VISA Instructions for Use video can be found here: VISA stroke vision screening video – YouTube