The association between self-checked visual field impairment and motor vehicle accidents among Japanese taxi drivers

In this cross-sectional study, we investigated the association between visual field impairment (VFI) and motor vehicle accidents (MVAs) among Japanese taxi drivers. We also evaluated the usefulness of a self-check test, the CLOCK CHART, as a screening tool for VFI. We recruited 1,227 male Japanese taxi drivers from 2018 to 2019. The CLOCK CHART detected defects (CCDD) were recorded as VFI. We collected data on visual field (VF)-related near miss incidents and MVAs over the previous five years using a self-administered questionnaire. A multivariable-adjusted generalized linear model was used to examine the association of the combination between CCDD and VF-related near misses with MVAs. We conducted a follow-up survey among 326 participants with CCDD to determine the proportion of newly diagnosed glaucoma. The proportion of MVAs was 61.9%, with a multivariable-adjusted prevalence ratio (95% confidence interval) of 1.22 (1.05-1.41) for MVAs in the group with both CCDD and VF-related near misses compared to the group without these factors. Further, 14 of these participants were newly diagnosed with glaucoma. A higher prevalence of MVAs was found among taxi drivers with both CCDD and VF-related near misses than for those without these factors. The CLOCK CHART may aid in identifying asymptomatic glaucoma.