Visual function of drivers and its relationship to road traffic accidents in Urban Africa

Associations between vision impairment and vision-related interventions on crash risk and driving cessation: systematic review and meta-analysis

OBJECTIVES

To systematically investigate the associations between vision impairment and risk of motor vehicle crash (MVC) involvement, and evaluate vision-related interventions to reduce MVCs.

DESIGN

Medline (Ovid), EMBASE and Global Health electronic databases were systematically searched from inception to March 2022 for observational and interventional English-language studies. Screening, data extraction and appraisals using the Joanna Briggs Institute appraisal tools were completed by two reviewers independently. Where appropriate, measures of association were converted into risk ratios (RRs) or ORs for meta-analysis.

PARTICIPANTS

Drivers of four-wheeled vehicles of all ages with no cognitive declines.

PRIMARY AND SECONDARY OUTCOMES

MVC involvement (primary) and driving cessation (secondary).

RESULTS

101 studies (n=778 052) were included after full-text review. 57 studies only involved older drivers (≥65 years) and 85 were in high-income settings. Heterogeneity in the data meant that most meta-analyses were underpowered as only 25 studies, further split into different groups of eye diseases and measures of vision, could be meta-analysed. The limited evidence from the meta-analyses suggests that visual field defects (four studies; RR 1.51 (95% CI 1.23, 1.85); p<0.001; I2=46.79%), and contrast sensitivity (two studies; RR 1.40 (95% CI 1.08, 1.80); p=0.01, I2=0.11%) and visual acuity loss (five studies; RR 1.21 (95% CI 1.02, 1.43); p=0.03, I2=28.49%) may increase crash risk. The results are more inconclusive for available evidence for associations of glaucoma (five studies, RR 1.27 (95% CI 0.67, 2.42); p=0.47; I2=93.48%) and cataract (two studies RR 1.15 (95% CI 0.97, 1.36); p=0.11; I2=3.96%) with crashes. Driving cessation may also be linked with glaucoma (two studies; RR 1.62 (95% CI 1.20, 2.19); p<0.001, I2=22.45%), age-related macular degeneration (AMD) (three studies; RR 2.21 (95% CI 1.47, 3.31); p<0.001, I2=75.11%) and reduced contrast sensitivity (three studies; RR 1.30 (95% CI 1.05, 1.61); p=0.02; I2=63.19%). Cataract surgery halved MVC risk (three studies; RR 0.55 (95% CI 0.34, 0.92); p=0.02; I2=97.10). Ranibizumab injections (four randomised controlled trials) prolonged driving in persons with AMD.

CONCLUSION

Impaired vision identified through a variety of measures is associated with both increased MVC involvement and cessation. Cataract surgery can reduce MVC risk. Despite literature being highly heterogeneous, this review shows that detection of vision problems and appropriate treatment are critical to road safety.

PROSPERO REGISTRATION NUMBER

CRD42020172153.

Refractive errors, road traffic accidents and long-term spectacle compliance amongst commercial taxi drivers in a major North-East Indian city

Purpose

To assess the prevalence of refractive error (RE) and its association with road traffic accidents (RTAs) and the subsequent long-term spectacle compliance and adherence to suggested appropriate strategies In Shillong, India.

Methods: This

prospective study was conducted between July and October 2019 among commercial taxi drivers (CTDs), with follow-up interviews conducted with a subset of respondents to assess long-term spectacle compliance after a year. Gross ophthalmologic examination was performed, including visual acuity and refraction. Descriptive statistics and Chi-square tests were conducted to assess the association between the type of REs, spectacle compliance, and selected sociodemographic and clinical variables. Multiple logistic regression was performed for analysis of the association between RTAs and sociodemographic, clinical, and work characteristics variables.

Results

A total of 382 (95.5%) CTDs completed interviews and gross eye examination. The prevalence of any RE in the worst eye was 28.8% (95% CI: 24.3-33.6). Presbyopia with or without distance vision was the commonest type of RE with 21.7% (95% CI: 17.7%-26.2). Among those who were prescribed spectacles, 70.5% needed near correction. Drivers with RE were nearly two times (OR: 2.6; 95% CI: 1.4-5.1) more likely to be involved in RTAs compared to those without any RE. Long-term spectacle compliance was at 40.9%. The predominant barrier reported for spectacle compliance was "can manage well without spectacles."

Conclusion

This survey has demonstrated a significant relationship between poor vision and occurrence of RTAs. There is an urgent need for tailor-made targeted interventions to address the eye health needs of CTDs in India.

Refractive errors among commercial drivers

Purpose

To determine the pattern of refractive error among commercial drivers in north India.

Methods

Descriptive study with convenient sampling conducted among commercial drivers of north India.

Results

A total of 213 (75.8%) heavy-vehicle and 68 (24.2%) light-vehicle drivers were screened for eye diseases. Refractive error for distance was reported in 44 (15.7%; 95% CI: 11.6-20.4) drivers. Hyperopia was reported in 23 (8.2%; 95% CI: 5.2-12) drivers, followed by myopia in 15 (5.3%; 95% CI: 3-8.6) drivers and astigmatism in six (2.1%; 95% CI: 0.7-4.5) drivers. Presbyopia was reported in 157 (55.8%) drivers. Dry eye was reported in 70 (24.9%), stereo deficiency in 77 (27.4%), and color vision deficiency in 11 (3.9%) drivers. Three drivers were diagnosed with cataract, and two were referred for retina evaluation.

Conclusion

Hyperopia in both eyes was the most common refractive error. Dry eye disease and color vision deficiency were also reported. Most of the drivers were not using spectacles for refractive error correction. Due to their mobile nature, drivers with cataract and retina diseases did not turn up for follow-up.

Visual Impairment and Risk of Self-Reported Road Traffic Crashes Among Bus Drivers in Bangladesh

PURPOSE

This study assesses the prevalence and the causes of visual impairment among bus drivers undergoing screening in Bangladesh and associations with self-reported crashes.

METHODS

Eye health screenings including refraction and questionnaires were conducted at 10 bus terminals in 7 districts of Bangladesh from June through August 2019. Presenting near and distance visual impairment and self-reported road traffic crashes were recorded.

RESULTS

Among 700 participants, nearly 1 in 5 (n = 126, 18.0%) had presented visual acuity (VA) in the better-seeing eye ≤6/9, not meeting the vision standard of Bangladesh for bus drivers. A majority of drivers (n = 492, 70.3%) had near or distance refractive error, and most who failed to reach the driving standard (88.1%, n = 111) could be improved with readily available treatment, either glasses or cataract surgery. A history of 1 or more road traffic crashes while driving a bus or minibus was reported by 62 (8.97%) participants. In multivariable models, factors significantly associated with near or distance visual impairment included older age [odds ratio (OR) per year 1.15, 95% confidence interval (CI): 1.12-1.18, P < 0.0001] and having no driver's license (OR 1.80, 95% CI: 1.04-3.13, P = 0.037). Self-reported history of a motor vehicle crash was associated with near or distance visual impairment (OR 2.45, 95% CI: 1.09-5.49, P = 0.030), even when adjusting for other factors such as age and weekly miles are driven.

CONCLUSIONS

Ensuring that bus drivers are screened to meet the required visual standards for driving while referring those who do not for treatment, can contribute to safer roads in this high-risk setting.

Vision impairment and traffic safety outcomes in low-income and middle-income countries: a systematic review and meta-analysis

BACKGROUND

Road traffic injuries are a major public health concern and their prevention requires concerted efforts. We aimed to systematically analyse the current evidence to establish whether any aspects of vision, and particularly interventions to improve vision function, are associated with traffic safety outcomes in low-income and middle-income countries (LMICs).

METHODS

We did a systematic review and meta-analysis to assess the association between poor vision and traffic safety outcomes. We searched MEDLINE, Embase, PsycINFO, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials in the Cochrane Library from database inception to April 2, 2020. We included any interventional or observational studies assessing whether vision is associated with traffic safety outcomes, studies describing prevalence of poor vision among drivers, and adherence to licensure regulations. We excluded studies done in high-income countries. We did a meta-analysis to explore the associations between vision function and traffic safety outcomes and a narrative synthesis to describe the prevalence of vision disorders and adherence to licensure requirements. We used random-effects models with residual maximum likelihood method. The systematic review protocol was registered on PROSPERO, CRD-42020180505.

FINDINGS

We identified 49 (1·8%) eligible articles of 2653 assessed and included 29 (59·2%) in the various data syntheses. 15 394 participants (mean sample size n=530 [SD 824]; mean age of 39·3 years [SD 9·65]; 1167 [7·6%] of 15 279 female) were included. The prevalence of vision impairment among road users ranged from 1·2% to 26·4% (26 studies), colour vision defects from 0·5% to 17·1% (15 studies), and visual field defects from 2·0% to 37·3% (ten studies). A substantial proportion (range 10·6-85·4%) received licences without undergoing mandatory vision testing. The meta-analysis revealed a 46% greater risk of having a road traffic crash among those with central acuity visual impairment (risk ratio [RR] 1·46 [95% CI 1·20-1·78]; p=0·0002, 13 studies) and a greater risk among those with defects in colour vision (RR 1·36 [1·01-1·82]; p=0·041, seven studies) or the visual field (RR 1·36 [1·25-1·48]; p<0·0001, seven studies). The I2 value for overall statistical heterogeneity was 63·4%.

INTERPRETATION

This systematic review shows a positive association between vision impairment and traffic crashes in LMICs. Our findings provide support for mandatory vision function assessment before issuing a driving licence.

FUNDING

None.

Visual Function of Drivers and its Relation to the Occurrence of Road Traffic Accidents in Saudi Arabia

BACKGROUND: The mortality rate due to road traffic accidents (RTA) is significantly high in Saudi Arabia (SA) compared to other countries. The visual function which includes good visual acuity (VA) and binocular vision are very important factors that can contribute to the incidence of RTA. AIM: The aim of this study is to investigate the association between refractive errors (REs) and the RTA in SA. METHODS: A total of 354 participants (mean age 22.67 ± 3.22 years) were recruited randomly to participate in this study from the population of Qassim district. Data collected using the questionnaire included participants’ age, sex, and education level, ocular and medical history, driving history as well as history of RTA. Ocular health examination including VA, RE measurements, and binocular vision function vision was measured and analyzed. RESULTS: The results of this study show that 48.3% of drivers had some form of REs with 3.4% being visually impaired. 217 (61.3%) of participants have had an RTA, and 119 (54.9%) of them have had more than two accidents in the past two years. The findings show no significant association between the occurrence of RTA and uncorrected REs or binocular vision dysfunction. CONCLUSION: Our data showed significantly higher rate of RTA among Saudi drivers which is much higher than any country in the world. The current Saudi regulations for obtaining driving license need to be modified, with implementing a comprehensive eye examination prior to acquiring or renewing drivers’ licenses.

Assessment of Sleep Deprivation and Fatigue Among Chemical Transportation Drivers in Chonburi, Thailand

BACKGROUND

Fatigue and sleepiness are inter-related and common among road transport drivers. In this study, sleep deprivation and fatigue among chemical transportation drivers were examined.

METHODS

A cross-sectional study surveying 107 drivers from three hazardous types of chemical production and transportation industries (nonflammable gases, flammable gases, and flammable liquids) was conducted. Data on sleep deprivation were collected using questionnaires of the Stanford Sleeping Scale and the Groningen Sleep Quality Scale. Fatigue was assessed using an interview questionnaire and a flicker fusion instrument.

RESULTS

Chemical drivers had a mean sleeping scale (Stanford Sleeping Scale) of 1.98 (standard deviation 1.00) and had a mean score of 1.89 (standard deviation 2.06) on the Groningen Sleep Quality Scale. High-risk drivers had higher scores in both the Stanford Sleeping Scale and the Groningen Sleep Quality Scale with a mean score of 2.59 and 4.62, respectively, and those differences reached statistical significance (p < 0.05). The prevalence of fatigue, as assessed through a critical flicker fusion analyzer, subjective fatigue question, and either of the instruments, was 32.32%, 16.16%, and 43.43%, respectively. Drivers who slept <7 hours and had poor sleep quality were found to have more fatigue than those who slept enough and well. Drivers who had a more sleepiness score resulted in significantly more objective fatigue than those who had a less sleepiness score.

CONCLUSION

Sleep quality and sleeping hour can affect a driver's fatigue. Optimization of work-rest model should be considered to improve productivity, driver retention, and road safety.

Time prediction model of subway transfer

Walking time prediction aims to deduce waiting time and travel time for passengers and provide a quantitative basis for the subway schedule management. This model is founded based on transfer passenger flow and type of pedestrian facilities. Chaoyangmen station in Beijing was taken as the learning set to obtain the relationship between transfer walking speed and passenger volume. The sectional passenger volume of different facilities was calculated related to the transfer passage classification. Model parameters were computed by curve fitting with respect to various pedestrian facilities. The testing set contained four transfer stations with large passenger volume. It is validated that the established model is effective and practical. The proposed model offers a real-time prediction method with good applicability. It can provide transfer scheme reference for passengers, meanwhile, improve the scheduling and management of the subway operation.

Visual function among commercial vehicle drivers in the central region of Ghana

AIM

To determine the relationship between some visual functions: colour vision defects, abnormal stereopsis, visual acuity and the occurrence of road traffic accident (RTAs) among commercial vehicle drivers in the central region of Ghana, and to assess their knowledge of these anomalies.

METHOD

A descriptive cross-sectional study employing a multi-stage random sampling approach was conducted in the major commercial towns within the central region of Ghana. Participants were taken through a comprehensive eye examination after the administration of a structured questionnaire.

RESULTS

520 male commercial vehicle drivers were enrolled for this study with a mean age of 39.23 years ±10.96 years and mean visual acuity of 0.02±0.08 logMAR. Protans were more likely to be involved in RTAs (χ(2)=6.194, p=0.034). However, there was no statistically significant association between abnormal stereopsis (OR=0.89 95% CI: 0.44-1.80, p=0.56), poor vision due to refractive error (χ(2)=3.090, p=0.388) and the occurrence of RTAs. While 86.9% were aware of abnormal stereopsis, only 45% were aware of colour vision defects. There was a statistically significant association between stereopsis anomaly and colour vision defect (r=0.371, p<0.005).

CONCLUSION

The study found an association between protanopia and RTAs but none between stereopsis anomalies, refractive errors and the occurrence of RTAs. Drivers were less knowledgeable on colour vision defects as compared to stereopsis anomalies.