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Objectives: We describe a novel rehabilitation tool for patients with homonymo us hemianopia based on a visual search (VS) paradigm that is portable, inexpensi ve, and easy to deploy. We hypothesised that by training patients to improve the efficiency of eye movements made in their blind field their disability would be alleviated. Methods: Twenty nine patients with homonymous visual field defects (HVFD) without neglect practised VS paradigms in 20 daily sessions over one mont h. Search fields comprising randomly positioned target and distracter elements, differing by a single feature, were displayed for three seconds on a dedicated t elevision monitor in the patients’homes. Improvements were assessed by examinin g response time (RT), error rates in VS, perimetric visual fields (VFs) and visu al search fields (VSFs), before and after treatment. Functional improvements wer e measured using objective visual tasks which represented activities of daily li ving (ADL) and a subjective questionnaire. Results: As a group the patients had significantly shorter mean RT in VS after training (P < 0.001) and demonstrated a variety of mechanisms to account for this . Improvements were confined to the training period and maint ained at follow up. Three patients had significantly longer RT after training. T hey had high initial error rates which improved with training. Patients performe d ADL tasks significantly faster after training and reported significant subject ive improvements. There was no concomitant enlargement of the VF, but there was a small but significant enlargement of the VSF. Conclusion: Patients can improve VS with practice. This usually involves shorter RTs, but occasionally a longer RT in a complex speed- accuracy trade-off. These changes translate to improved overall visual functi on, assessed objectively and subjectively, suggesting that they represent robust training effects. The underlying mechanism may involve the adoption of compensa tory eye movement strategies.
Objectives: We describe a novel rehabilitation tool for patients with homonymo us hemianopia based on a visual search (VS) paradigm that is portable, inexpensi ve, and easy to deploy. We hypothesised that by training patients to improve the efficiency of eye movements made in Their blind field their disability would be alleviated. Methods: Twenty nine patients with homonymous visual field defects (HVFD) without neglect practiced VS paradigms in 20 daily sessions over one mont h. Search lines comprising randomly positioned target and distracter elements, differing by a single feature, were displayed for three seconds on a dedicated t elevision monitor in the patients’ homes. Improvements were assessed by examinin g response time (RT), error rates in VS, perimetric visual fields (VFs) and visu search fields (VSFs) , before and after treatment. Functional improvements wer e measured using objective visual tasks which represented activities of daily li ving (ADL) and a subjective questio Results: As a group the patients had significantly shorter mean RT in VS after training (P <0.001) and demonstrated a variety of mechanisms to account for this. Improvements were confined to the training period and maint ained at follow up. Three patients T hey had high initial error rates which improved with training. Patients performe d ADL tasks significantly faster after training and posted significant subject ive improvements. There was no concomitant enlargement of the VF, but there was a small but Significant enlargement of the VSF. Conclusion: Patients can improve VS with practice. This usually makes shorter RTs, but occasionally a longer RT in a complex speed- accuracy trade-off. These changes translate to improve overall visual functi on, rated objectively and subjectively , suggesting that they represent robust training effects. The underlying mechanism may involve the adoption of compensatory eye movement strategies.