The Effects of Compensatory Scanning Training on Mobility in Patients with Homonymous Visual Field Defects: A Randomized Controlled Trial.
BACKGROUND
Homonymous visual field defects (HVFD) are a common consequence of postchiasmatic acquired brain injury and often lead to mobility-related difficulties. Different types of compensatory scanning training have been developed, aimed at decreasing consequences of the HVFD by changing visual scanning.


OBJECTIVE
The aim of the present study is to examine the effects of a compensatory scanning training program using horizontal scanning on mobility-related activities and participation in daily life.


METHODS
The main interest of this study is to assess the effectiveness of training on mobility-related activities and participation in daily life. Visual scanning tests, such as dot counting and visual search, and control measures for visual functions and reading have been included as well. First, it is examined how performance on scanning and mobility-related measures is affected in patients with HVFD by comparing scores with scores of a healthy control group (n = 25). Second, the effect of training is assessed using an RCT design, in which performance of 26 patients before and after training is compared to performance of 23 patients in a waiting list control group.


RESULTS
Self-reported improvements after training were found, accompanied by improvements in detecting peripheral stimuli and avoiding obstacles during walking, especially in dual task situations in which a second task limits the attentional capacity available for compensatory scanning. Training only improved mobility-related activities in which detection of peripheral stimuli is important, while no improvement was found on tests that require other visual skills, such as reading, visual counting and visual search.


CONCLUSIONS
This is the first RCT to evaluate the effects of a compensatory scanning training that is based on a systematic horizontal scanning rhythm. This training improved mobility-related activities. The results suggest that different types of compensatory scanning strategies are appropriate for different types of activities.


BACKGROUND
ISRCTN Registry ISRCTN16833414.
Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen, The Netherlands; Royal Dutch Visio: Centre of Expertise for Blind and Partially Sighted People, Haren, The Netherlands.
Gera A
GA
de Haan
Royal Dutch Visio: Centre of Expertise for Blind and Partially Sighted People, Haren, The Netherlands.
Bart J M
BJ
Melis-Dankers
Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen, The Netherlands; Department of Neurology, University Medical Center Groningen, Groningen, The Netherlands.
Wiebo H
WH
Brouwer
Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen, The Netherlands.
Oliver
O
Tucha
Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen, The Netherlands; Royal Dutch Visio: Centre of Expertise for Blind and Partially Sighted People, Haren, The Netherlands.
Joost
J
Heutink
D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D005260:Female; D006423:Hemianopsia / Q000209:etiology / Q000503:physiopathology* / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance / Q000502:physiology*; D057566:Self Report; D016896:Treatment Outcome