Driving performance of glaucoma patients correlates with peripheral visual field loss.

PURPOSE

To identify clinical vision measures that are associated with the driving performance of glaucoma patients who have visual field loss and visual acuity better than 20/100 and to compare the driving performance of glaucoma patients with the driving performance of a group of age- and sex-equivalent individuals without eye disease.

PATIENTS

Forty patients with glaucoma and 17 normally sighted control subjects participated in this study.

METHODS

Clinical vision data, consisting of visual acuity, letter contrast sensitivity, and visual fields, were collected. Driving performance was assessed by (1) an interactive driving simulator that measured 7 indices of performance (including number of accidents) and (2) the self-reported accident involvement for the past 5 years.

MAIN OUTCOME MEASURES

Driving simulator performance and real-world, self-reported accident involvement.

RESULTS

The number of accidents as measured on the driving simulator in the glaucoma group was significantly correlated with three Goldmann visual field measures: combined horizontal extent (rho = -0.47, P = 0.01), total horizontal extent (rho = -0.49, P = 0.007), and total peripheral extent (rho = -0.55, P = 0.002). There were no statistically significant correlations between the driving performance of the glaucoma group and the visual acuity or contrast sensitivity measures. When compared with the control group, a significantly greater proportion of the glaucoma group reported having at least one real-world accident within the past 5 years (Fisher exact test, P = 0.005).

CONCLUSIONS

Visual field reduced to less than 100 degrees of horizontal extent may place patients with peripheral field loss at greater accident risk. A higher incidence of real-world and simulator accidents was found for the group with glaucoma.