Driving Difficulties and Coping Strategies in Persons with Homonymous Quadrantanopia or Homonymous Scotoma.

INTRODUCTION

This study, conducted in the United States, investigated the challenges faced by drivers with homonymous visual field loss and their coping strategies, including the use of in-vehicle Advanced Driver Assistance Systems (ADAS).

METHODS

Four current drivers with either homonymous quadrantanopia or homonymous scotoma caused by a stroke completed an in-depth semi-structured telephone interview. Using mostly open-ended questions, the interview addressed the difficulties encountered while driving, strategies used to cope with the difficulties, and the use of ADAS.

RESULTS

The main difficulties related to seeing objects on side of the field loss especially at intersections and when merging or changing lanes. Cases with left-sided field loss reported problems with left turns and seeing oncoming cars at intersections. Cases with homonymous scotomas described how cars disappeared in and out of the scotoma. Two cases reported many driving difficulties at first, but fewer difficulties as they became used to driving with the field loss. The most common coping strategies included scanning to the side of the field loss (including large scans with head movements), use of rearview/side mirrors, adding mirrors to the car, leaving more space on the side of the field loss, avoiding difficult driving situations and the use of ADAS (blind spot warning, GPS navigation and rearview camera).

DISCUSSION

All cases reported some difficulties consistent with those found in on-road and driving simulator studies of individuals with homonymous visual field loss. Over time they each reported developing a set of strategies, including use of ADAS, for coping with the field loss that enabled them to be active drivers with relatively few self-imposed restrictions.

IMPLICATIONS FOR PRACTITIONERS

Advising drivers with stroke-related field loss about potential difficulties and compensatory strategies is an important part of preparation for return to driving. The paper provides examples of problem situations, coping strategies and ADAS use which can be used to guide discussion.