Abstract
Purpose :
Older drivers with glaucoma are at risk of being at fault and injured in a motor vehicle accident. There is no clear consensus, however, on how vision is related to unsafe driving, due to limited studies that comprehensively evaluate vision and real-world driving. This study evaluates the association between visual acuity, visual field, contrast, and glare tests and driving performance on an on-road driving evaluation in older drivers with and without glaucoma.
Methods :
This cohort study evaluated 158 drivers with varying severities of glaucoma (n=111) and ocular controls (n=47), ages 55-90 years, recruited from a tertiary care center. Participants underwent a vision assessment including ETDRS distance visual acuity (DVA) and Sloan near visual acuity (NVA), Humphrey Visual Field 24-2 (VF), Esterman disability test, MARS contrast sensitivity (CS), and glare using the Brightness Acuity Tester (BAT) on low and medium settings using the MARS chart. Participants completed an on-road driving evaluation by a driving rehabilitation specialist, masked to driver diagnosis, who assigned an overall driving score later categorized as pass vs. at-risk.
Results :
In this sample, 29.7% (n=33) of drivers with glaucoma received an at-risk score compared to 4.2% (n=2) of control drivers. Drivers with glaucoma performed worse (p<0.05) on all vision tests (DVA, NVA, VF, Esterman, CS, and BAT on low and medium settings) compared to control drivers. In the total sample, worse vision performance was correlated with at-risk driving score (p<0.05) for each of the vision tests: DVA (r=-0.37), NVA (r=-0.24), HVF of best eye (r=-0.35), Esterman (r=-0.30), CS (r=-0.41), BAT on low (r=-0.46) and medium (r=-0.39) settings. Poor vision performance with BAT on low setting was the strongest predictor of at-risk driving (stepwise logistic regression).
Conclusions :
Current vision requirements for driving mainly assess distance visual acuity and visual fields, and are not evidence-based. Our results suggest that poor performance on multiple vision tests is associated with at-risk driving. Glare and contrast sensitivity are not routinely evaluated for driving licensure yet were strongly associated with at-risk driving; glare with low setting being the strongest predictor. These results can help develop evidence-based vision requirements for driving to improve driving safety of older drivers with and without glaucoma.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.