Visual function of commercial drivers and its relationship with road traffic crashes

Abstract

Objectives: To determine the visual function status of commercial vehicle drivers in Lokoja, Nigeria and its relationship with road traffic crashes (RTCs). Materials and Methods: The study is a population-based descriptive cross-sectional study, conducted within a 3-month period. Participants were recruited using a multi-staged sampling technique. All subjects had visual acuity done for both distant and near vision, contrast sensitivity, colour vision, anterior segment examination with pen torch, visual field (VF) and fundus photography. A standard interviewer-administered questionnaire was used, with sections for sociodemographic data, driving and licence history, history of involvement in RTC and ocular examination. Data obtained was analysed with epidemiology information (EPI INFO) (version 7.2). Results: All the participants were males; the mean age was 43.66 years although majority of the participants were in the 31–40-year age group. Most of the participants (41.9%) have secondary education and the mean number of driving years is 18.34%. About 70% of the participants were aware that visual screening is a pre-requisite for driving; however, only one third (33.1%) have had vision screening in the past and just a few of them had it in relation to obtaining driver’s licence; 11.3% had it before licence issuance and 4.3% during licence renewal. Majority of the participants had good visual functions; 87.9%, 93.5%, 90.3% and 91.1% had normal visual acuity, contrast sensitivity, colour vision and VF, respectively. Less than 20% of the participants with poor visual function have had RTC in the past. The most common cause of visual impairment among the participants was uncorrected refractive error. Conclusion: There was no statistically significant relationship between visual impairment and RTC; however, visually impaired drivers drive less often. Furthermore, there was no significant relationship between defective VF, contrast sensitivity and colour vision with RTC. Some participants had visual impairment yet have a valid driver’s licence, thus the drivers and vehicle licensing authority need to be stricter and ensure that only drivers who meet the minimum legal requirement are issued licence to drive.