Driving with Glaucoma: Task Performance and Gaze Movements.
OBJECTIVE
The aim of this pilot study was to assess the driving performance and the visual search behavior, that is, eye and head movements, of patients with glaucoma in comparison to healthy-sighted subjects during a simulated driving test.


METHODS
Driving performance and gaze behavior of six glaucoma patients and eight healthy-sighted age- and sex-matched control subjects were compared in an advanced driving simulator. All subjects underwent a 40-minute driving test including nine hazardous situations on city and rural roads. Fitness to drive was assessed by a masked driving instructor according to the requirements of the official German driving test. Several driving performance measures were investigated: lane position, time to line crossing, and speed. Additionally, eye and head movements were tracked and analyzed.


RESULTS
Three out of six glaucoma patients passed the driving test and their driving performance was indistinguishable from that of the control group. Patients who passed the test showed an increased visual exploration in comparison to patients who failed; that is, they showed increased number of head and gaze movements toward eccentric regions. Furthermore, patients who failed the test showed a rightward bias in average lane position, probably in an attempt to maximize the safety margin to oncoming traffic.


CONCLUSIONS
Our study suggests that a considerable subgroup of subjects with binocular glaucomatous visual field loss shows a safe driving behavior in a virtual reality environment, because they adapt their viewing behavior by increasing their visual scanning. Hence, binocular visual field loss does not necessarily influence driving safety. We recommend that more individualized driving assessments, which will take into account the patient's ability to compensate, are required.
*MSc †PhD ‡MD Department of Computer Engineering, University of Tübingen, Tübingen, Germany (TCK, EK, WR); Competence Center "Vision Research", Study Course "Ophthalmic Optics/Audiology", University of Applied Sciences Aalen, Aalen, Germany (TCK, US, EP); Center for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany (MH, KA, US); Daimler AG, Research and Development, Sindelfingen, Germany (KN); and Department of Ophthalmology, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom (EP).
Thomas C
TC
Kübler
Enkelejda
E
Kasneci
Wolfgang
W
Rosenstiel
Martin
M
Heister
Kathrin
K
Aehling
Katja
K
Nagel
Ulrich
U
Schiefer
Elena
E
Papageorgiou
D000368:Aged; D001333:Automobile Driver Examination; D001334:Automobile Driving; D003198:Computer Simulation; D005133:Eye Movements / Q000502:physiology; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D005901:Glaucoma / Q000503:physiopathology*; D019416:Head Movements / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012449:Safety; D013647:Task Performance and Analysis; D014786:Vision Disorders / Q000503:physiopathology*; D015348:Vision, Binocular / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology