Driving cessation and driving limitation in glaucoma: the Salisbury Eye Evaluation Project.

OBJECTIVE: To determine if glaucoma is associated with driving limitation or cessation.
DESIGN: Cross-sectional analysis within a longitudinal, population-based cohort study. PARTICIPANTS AND CONTROLS: One thousand one hundred thirty-five ever-drivers between 73 and 93, including 70 subjects with unilateral and 68 subjects with bilateral glaucoma.
METHODS: All subjects reported their driving habits during each of 4 study rounds. During the fourth and final study round, subjects were assessed systematically for the presence of glaucoma. MAIN OUTCOME MEASURES: Self-reported driving cessation or driving limitation, including cessation of night driving, driving fewer than 3000 miles annually, or cessation of driving in unfamiliar areas.
RESULTS: Fifteen percent of subjects without glaucoma no longer were driving at the end of the cohort study, compared with 21% of unilateral glaucoma subjects (P = 0.2) and 41% of bilateral glaucoma subjects (P<0.001). Multivariate regression analysis showed that bilateral (odds ratio [OR], 2.6; P = 0.002), but not unilateral (OR, 1.5; P = 0.3), glaucoma subjects were more likely no longer to be driving when compared with subjects without glaucoma. The odds that bilateral glaucoma subjects no longer were driving doubled for every 5 dB of visual field (VF) worsening in the better eye (P<0.001). Driving cessation within the previous 2 years was analyzed using separate multiple regression models, and both bilateral (OR, 3.6; P = 0.004) and unilateral (OR, 2.4; P = 0.06) glaucoma subjects were more likely to stop driving over this period than subjects without glaucoma. Driving cessation associated with bilateral glaucoma was present in 0.82% of the population, or 1 in every 122 individuals. Greater numbers of driving limitations were not more likely among subjects with glaucoma than subjects without glaucoma. However, bilateral glaucoma subjects did attribute more driving limitations to difficulties with their vision than subjects without glaucoma (OR, 2.2; P = 0.02).
CONCLUSIONS: Bilateral, and possibly unilateral, glaucoma is associated with significantly higher rates of driving cessation among the elderly. The substantial difference in driving patterns seen with different degrees of better-eye VF damage suggests that minimizing VF loss in the better-seeing eye is associated with better functional outcomes.