Date Presented 04/04/19
This descriptive case study compares preparatory, occupation-based, and combined-intervention approaches for the compensatory treatment of visual field deficits as a feasibility study. Using the AMPS to examine occupational performance, it appears the combined training was most effective for visual compensation of everyday IADLs. However, results of eye tracking with a driving simulator offers contrasting evidence for safety when attempting to compensate for visual deficits with scanning.
Primary Author and Speaker: Rachel Gartz
Additional Authors and Speakers: Anne Dickerson, Jennifer Radloff
PURPOSE: Although much research exists regarding overall rehabilitation interventions poststroke, there is a lack of evidence for treatment of visual deficits1. This study’s research question compared the effectiveness of preparatory, occupation-based, and combined occupational therapy treatment for visual scanning training on improving occupational performance in IADLs for an individual who had sustained a stroke. Additionally, while eye tracking technology has been used in limited occupational therapy studies for neglect,2 no studies have yet used eye tracking in the context of daily occupations. In this case, the technology was used to ascertain the effects of visual field deficits poststroke compared to a healthy control.
DESIGN: A descriptive case study design with a a 55-year-old female who had a stroke 7 years prior and had chronic, bitemporal visual field deficits, but no spatial neglect or significant motor or cognitive deficits. A same age/gender control was used to compare scanning performance during IADL tasks (driving on a simulator and cooking tasks) looking at gaze patterns with eye track technology.
METHODS: The participant underwent three visual scanning treatments – preparatory, occupation-based, and combined. The Assessment of Motor and Process Skills (AMPS) was used as the outcome measures (motor & process) as well as standardized measures on the Vision Coach (full field, 60 dots, all red, speed 0, fixator off) at four points of time: 1)pretest, 2)after the preparatory intervention, 3)after occupation-based intervention, and 4)after combined intervention to determine the change in performance after each intervention. Interventions were 45-60 minutes, twice a wk, for 4 wks each intervention. After completion, the participant completed 2 cooking tasks and a task on the driving simulator using the Tobii Glasses Pro eye tracking glasses. A calibrated rater’s AMPS data was compared between 4 times and to the AMPS standardization sample to determine observable improvements. Vision Coach data (time) was also compared. 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 using the Tobii Analyzer software.
RESULTS: Using AMPS logic scores in the order as implemented, 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). Process skills scores were 0.8 (questionable to mild inefficiency), 1.0 (questionable inefficiency), 0.8 (questionable to mild inefficiency), 1.2 (questionable inefficiency). With an observable difference being at least 0.30 logits3, both motor & process improved from "outside expected age range" to "with expected age range" with over .3 logits for both. Comparison of the eye tracking measures and heat maps revealed differences between time spent viewing areas of the visual field, including during 2 crashes on the driving simulator, suggested compensation was effective in daily tasks, but may be ineffective for driving.
CONCLUSION: In this exploratory study of a client with chronic visual field deficits poststroke, visual scanning training appeared to be the most effective compensatory method when using combined (preparatory & occupational) training. As a feasibility study, the protocols and measurement outcomes can be used for a RCT study and practitioners can design interventions for clients with visual deficits poststroke. This study also supports exploration of the use of eye tracking technology to understand visual scanning compensation for IADLs and implications for driving with visual deficits.
References
1. Duncan, P. W., Zorowitz, R., Bates, B., Choi, J. Y., Glasberg, J. J., Graham, G. D., . . . Reker, D. (2005). Management of adult stroke rehabilitation care: A clinical practice guideline. Stroke, 36(9), e100-43. doi:36/9/e100
2. Kortman, B., & Nicholls, K. (2016). Assessing for unilateral spatial neglect using eye-tracking glasses: A feasibility study. Occupational Therapy in Health Care, 30(4), 344-355. doi:10.1080/07380577.2016.1208858
3. Fisher, A. G., & Jones, K. B. (2012). Assessment of Motor and Process Skills (7th ed.). Fort Collins, CO: Three Star Press.
