Development of V-FAST: a vision screening tool for ambulance staff
Published Date: 11th August 2020
Publication Authors: Bates R
Background
About two-thirds of stroke survivors experience visual problems and most patients who have a stroke limited to the occipital lobe will have visual impairments only.
Aim
The V-FAST screening tool, which assesses visual symptoms, eye movements, visual field and visual extinction, and a training package to improve diagnostic accuracy of identifying visual impairment in hyperacute strokes were developed and evaluated.
Methods
The educational package was developed through focus groups. The pilot study screened patients with suspected strokes in prehospital settings; the V-FAST tool was used with 43 of these patients. Each participant was also assessed in hospital using the National Institutes of Health Stroke Scale (NIHSS) and the score compared to V-FAST screening results to determine sensitivity and specificity.
Results
The education package includes detailed instructions with video. In the pilot study, V-FAST detected visual impairment in 75.9% of FAST-positive and 80% of FAST-negative strokes. Sensitivity and specificity compared to NIHSS were 85.7% and 42.1% respectively.
Conclusion
V-FAST has good sensitivity to detect vision impairment when screening for possible strokes. The added education package facilitates greater knowledge and understanding of potential visual problems caused by stroke.
Rowe, FJ; Bates, R et al. (2020). Development of V-FAST: a vision screening tool for ambulance staff. Journal of Paramedic Practice. 12 (8), 324-331