Abstract
Purpose :
Drivers with homonymous visual field loss (HVFL) can compensate by scanning to their blind side. However, they sometimes do not scan sufficiently when approaching intersections where large head scans are needed to view the cross-street on the blind side. Previously we found auditory reminder cues were helpful in promoting large blind-side head scans. Here we implemented the cues as a training tool in the driving simulator and investigated how scanning behavior changed during training.
Methods :
To date, 3 subjects with HVFL participated. S1 (59 y), former driver, had complete right hemianopia for 23 years and a blind left eye. S2 (84 y) and S3 (55 y), current drivers, had incomplete left hemianopia for 2 and 7 years, respectively. None had received scanning training previously. They each completed 3 training sessions in the simulator with 3 drives per session and 36-38 intersections per drive. Head position was monitored. Subjects received an auditory reminder (beep) from a loudspeaker on their blind side if they did not make a large enough (>20°) blind-side head scan before an intersection. At 10 intersections peripheral (54° eccentricity) motorcycle hazards approached along the cross-street; subjects pressed the horn to indicate detection.
Results :
During training, S1’s average number of reminders reduced from 10% to 8% per session, S2’s from 46% to 22%, and S3’s from 12% to 7%. S1’s detection rate was high on their blind side (>93%) but lower on their seeing side (average 62% per session) due to a focus on blind side scanning and left field restriction from the blind left eye. S2 and S3 had high detections rates on both sides (>87%). S1 and S3 stated they modified their scanning to avoid receiving reminder cues during training. S2 and S3 felt training improved their scanning behavior by increasing their awareness of the road environment and the necessity of blind-side scans, but S1 was unsure due to his longstanding focus on blind-side scanning. Both S2 and S3 reported applying the training when driving on the road.
Conclusions :
As training progressed and subjects learned to make early blind side head scans, the number of reminders decreased, most noticeably for S2, the oldest participant with the most recent HVFL onset. The two current drivers perceived improvements in scanning behavior and began implementing the training in their daily driving.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.