On-Road Driving Performance in Patients with Moderate and Advanced Glaucoma

Purpose: Glaucoma is an age-related ocular disease that damages peripheral vision, which is necessary for safe driving and traffic vigilance. The purpose of this study is to determine the extent that glaucoma affects driving performance and evaluate factors associated with unsafe driving. Using the gold standard of an on-road driving test (ORDT), we compared the driving performance of patients with moderate or advanced glaucoma to normal age-matched controls. Methods: The sample consisted of 22 elder patients (age 55+) with moderate to advanced glaucoma, and 38 age-matched subjects with no ocular disease. Through visual, cognitive and motor tests, participants were clinically assessed for off-road functioning related to the complex task of driving. The main outcome variables for driving ability was a score of pass, marginal pass, or fail on the 12-mile modified Washington Univserity Road Test (mWURT) and a tally of the number of at-fault critical interventions. Results: Eleven patients (50%) scored a marginal pass or fail on the ORDT compared to 8 (21%) normal controls. Therefore, patients with moderate or advanced glaucoma were 3.8 times more likely to receive a marginal pass or fail than normal controls (95% CI, 1.20 – 11.76). Participant age, cognitive and motor ability, and traffic knowledge were significantly (p \u3c 0.05) correlated to a marginal pass or fail score. In addition, 7 (32%) glaucoma patients required 1 or more at-fault critical interventions compared to 6 (16%) normal participants. Conclusion: In this sample, older drivers with moderate or advanced glaucoma performed worse overall and had a higher proportion of at-fault critical interventions on the on-road driving test than normal age-matched controls. A combination of visual and cognitive factors were associated with poor driving performance, indicating that driving is a complex multifactorial process that needs to be better understood in the elderly and vision impaired. Fostering a safe driving environment where patients are not deterred to participate (out of fear of losing licensure) is needed to obtain a larger sample size and prevent selection bias in subsequent follow-up investigations