The contribution of the useful field of view (UFOV procedure) to allow brain-damaged patients to drive again

Abstract

Introduction/Background Visual field disorders, frequently observed in brain-damaged patients, are associated with an adverse prognosis in outcome activities as car driving. In France, a prefectorial order contraindicates driving if the visual field is inferior to 120° on the meridian axis, inferior to 20° on a vertical axis and with defects in a 20° radius from the center. Our aim was to study patients’ abilities to distribute their visual attention in space, in case of visual field disorders. Material and method Thirty-eight patients with a hemianopia and 49 with a visual defect in the central 20 degrees performed a Useful Field Of View procedure (UFOV). This computer-based assessment contains three attentional tasks: a processing speed task to detect a target in central vision, a divided attention task involving to detect simultaneously a central and a peripheral target, a selective attention task consisting in detection of a central and a peripheral target in attendance of visual distractors. Brain-damaged patient performance was compared to cut-off scores elaborated in a previous study with healthy neurological volunteers (Marks et al., 2015). Results Only one patient with hemianopia reached normal performance in UFOV tasks. All others patients with hemianopia could not distribute their visual attention in the amputee visual field. However, ten patients among the 49 with a visual defect in the central 20 degrees reached normal performance in UFOV tasks, proving their normal abilities to distribute visual attention in space despite the visual field disorder. Conclusion When the visual field disorder concerns the central 20 degrees, some patients could balance out it using their visual attentional abilities and maybe in these cases, a driving simulator try and/or an “on-road” try could be proposed before to examine the driving restriction.