Obstacle Avoidance, Visual Detection Performance, and Eye-Scanning Behavior of Glaucoma Patients in a Driving Simulator: A Preliminary Study

Abstract

The objective of this study was to evaluate differences in driving performance, visual detection performance, and eye-scanning behavior between glaucoma patients and control participants without glaucoma. Glaucoma patients (n = 23) and control participants (n = 12) completed four 5-min driving sessions in a simulator. The participants were instructed to maintain the car in the right lane of a two-lane highway while their speed was automatically maintained at 100 km/h. Additional tasks per session were: Session 1: none, Session 2: verbalization of projected letters, Session 3: avoidance of static obstacles, and Session 4: combined letter verbalization and avoidance of static obstacles. Eye-scanning behavior was recorded with an eye-tracker. Results showed no statistically significant differences between patients and control participants for lane keeping, obstacle avoidance, and eye-scanning behavior. Steering activity, number of missed letters, and letter reaction time were significantly higher for glaucoma patients than for control participants. In conclusion, glaucoma patients were able to avoid objects and maintain a nominal lane keeping performance, but applied more steering input than control participants, and were more likely than control participants to miss peripherally projected stimuli. The eye-tracking results suggest that glaucoma patients did not use extra visual search to compensate for their visual field loss. Limitations of the study, such as small sample size, are discussed.

An assessment of driving fitness in patients with visual impairment to understand the elevated risk of motor vehicle accidents

“…Prado Vega et al 26 studied the effect of task complexity in a DS and found that it had a significant impact on patient performance. Our DS may therefore have underestimated the risk of collisions due to the simplicity of the task presented to the patients: they did not need to operate the steering wheel or accelerator, only to watch the road and brake.…”

“…Past studies have confirmed that DS systems are a powerful means of evaluating the effect on driving ability of alcohol, 15 lack of sleep 16 and drug use, 17 as well as hemianopia [18][19][20] and other visual field defects. [21][22][23][24][25][26] Moreover, DSs have been found to compare favourably with on-road testing. 27 28 In the present study, patients with glaucoma with advanced visual field damage served as a model of visual impairment.…”

Impact of superior and inferior visual field loss on hazard detection in a computer-based driving test

“…Driving simulators allow for standardised and objective assessments of driving performance, providing higher control and repeatability when compared with on-road assessments while maintaining the appearance of driving 30. However, the virtual tasks are less realistic than real driving, for example, detecting a target letter flashed on the driving screen31 or a single target hazard such as a pedestrian 15. Although still far removed from actual driving, our current computer-based set-up maintained this experimental control but at least used actual driving scenarios typically encountered on the road.…”

Ocular disease and driving

“…Similarly, a recent case‐controlled study reported that patients with advanced glaucoma (mean defect worse than ‐12 dB in both eyes) had significantly more simulator crashes in some driving scenarios, which were related to integrated visual field sensitivity; however, the drivers were not required to operate the steering wheel or the brake. In another small scale simulator study, drivers with glaucoma made more steering actions and were worse on a detection task than controls but there were no other between group differences; however, it should be noted, that there was no possibility of compensating for visual impairment in this study by reducing driving speeds as speed was fixed. Finally, performance on a divided‐attention reaction time task in a simulator study has been reported to be linked with self‐reported crashes in glaucoma patients; however, the reliability of self‐reported crashes has been called into question …”