The Effectiveness of Visual Scanning Training to Improve Functional Performance Poststroke: A Case Study in Eastern North Carolina

Rationale: Although an abundance of research exists regarding overall rehabilitation interventions poststroke, there is a lack of evidence for treatment of visual deficits. Additionally, eye tracking glasses may be used to further understand the effects of visual field deficits poststroke, though no studies have yet used eye tracking in the context of daily occupations. Purpose: This study evaluated the effectiveness of component-based, occupation-based, and combined occupational therapy treatment for visual scanning training on improving occupational performance in instrumental activities of daily living. The second portion of the study described the differences in visual scanning tendencies during cooking and driving, between an individual with a visual field deficit poststroke and a healthy control of similar age and gender. Design: This study used a case study design with a health control for the eye tracking portion. Participant: The participant was a 55-year-old female who had a stroke 7 years prior. Methods: One participant with a visual field deficit poststroke underwent three visual scanning treatments - component-based, occupation-based, and combined. The researchers administered the Assessment of Motor and Process Skills (AMPS) and took standardized measures on the Vision Coach (full field, 60 dots, all red, speed 0, fixator off) at pretest, after the component-based intervention, after the occupation-based intervention, and after the combined intervention to determine the change in occupational performance - measured by motor skills and process skills - after each intervention. After the interventions were complete, the participant completed a cooking tasks and a task on the driving simulator, while wearing the Tobii Glasses Pro 2 eye tracking glasses. Analysis: Data from the AMPS was compared between times and to the AMPS standardization sample to determine observable improvements. Vision Coach data was also compared between times. The participant's eye tracking data - duration of first fixation, total visit duration, and heat maps - were compared to a healthy control of the same age and gender. Results: With regards to the AMPS and in order of time, the participant scores of motor skills were 1.4 (mild to moderate increased physical effort), 1.8 (questionable to mild increased physical effort), 2.0 (questionable increased physical effort), and 1.8 (questionable to mild increased physical effort). Her scores of process skills were 0.8 (questionable to mild inefficiency), 1.0 (questionable inefficiency), 0.8 (questionable to mild inefficiency), 1.2 (questionable inefficiency). As per the AMPS standardization sample, an observable difference is one of 0.30 logits or more. Comparison of the eye tracking measures and heat maps revealed differences between time spent viewing areas of the visual field, including during two crashes on the driving simulator. Discussion: Overall, visual scanning training as a compensatory method was effective for this participant and could therefore be considered by occupational therapists when treating clients with chronic visual field deficits poststroke, with the combined training being most effective. This study also supports the use of eye tracking glasses during occupations to understand visual scanning tendencies between individuals with and without visual deficits