Assessment of driving performance in patients with retinitis pigmentosa

The driving performance of 21 subjects with retinitis pigmentosa (RP) and varying degrees of peripheral field loss was compared with the performance of 31 normally sighted control subjects who did not differ statistically from the subjects with RP in age, gender, years of driving experience, or miles driven per year. Driving performance was assessed by self-reported accident frequency and by an evaluation of performance on an interactive driving simulator. A significantly greater proportion of individuals had self-reported accidents in the RP group than in the normal group. Likewise, a significantly greater proportion of subjects with RP than normal subjects had accidents on the driving simulator. Logistic regression analyses indicated that binocular horizontal field extent and binocular field area significantly differentiated between those having no self-reported accidents and those subjects with RP having one or more self-reported accidents. Because the simulator indexes were correlated with visual field measures for the subjects with RP, no additional information was incorporated into the regression model by adding the simulator measures. Therefore, our results indicate that visual field loss is a primary correlate of automotive accidents in individuals with RP.