Data were analyzed with commercial software (SPSS, ver. 15.0; SPSS Inc., Chicago, IL). Analyses were two-tailed, and P < 0.05 was considered statistically significant. Assumptions underlying all statistical tests were verified. Descriptive statistics were calculated for demographic, medical, vision, and driving performance data. Group differences were evaluated with the Student’s t-test, Mann-Whitney U test, and χ2 test for continuous, ordinal, and nominal data, respectively. Logistic regression analysis was used to calculate an odds ratio (OR) and corresponding 95% confidence interval (CI) for the association between glaucoma and critical interventions during the driving test, with adjustment for the possible confounding effects of age, sex, number of systemic medications, use of psychotropic medication, and driving exposure. For the glaucoma group, associations between visual functions, number of satisfactory driving maneuvers, and overall rating of driving skills were evaluated using Spearman’s rank correlation coefficient. Associations between visual functions and critical interventions were evaluated by using logistic regression analysis to calculate ORs and 95% CIs, where vision measures were dichotomized using cutoff criteria considered to be clinically important (e.g., MD cutoff at 2 SD less than the control group mean), with adjustment of statistically significant results for the potentially confounding variables stated earlier.