Driver licensing and motor vehicle crash rates among young adults with amblyopia and unilateral vision impairment

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.

A Review of Driving and Binocularity

Although most jurisdictions allow stereoscopically deficient and monocular individuals to drive, studies regarding these visual components' effects on driving have to date yielded contradicting results. Interviews, record reviews, and experiments have been used to unmask these effects. In interviews, participants with amblyopia reported several difficulties operating automobiles. Record reviews yielded mixed results, with studies revealing an increased crash rate and/or severity in a group of stereoscopically deficient commercial drivers, whereas studies of non-commercial drivers failed to make that association. Furthermore, experimental studies showed that individuals with reduced stereopsis braked earlier and were less likely to crash. With regard to monocularity, real-life experiments failed to demonstrate a poorer driving performance and simulation studies showed that drivers with sudden monocularity were more likely to crash and drive off the road. [J Pediatr Ophthalmol Strabismus. 2022;59(1):6-12.].

Influence of Vision on Drivers: A Pilot Study

Background: Driving is the main mode of transportation in many countries, and visual safety depends largely on good visual health. The objective of this study is to analyze the visual health of Spanish drivers; as well as analyze the difference between professional and non-professional drivers. Methods: A visual screening was carried out in Spanish drivers from all over Spain, in which the following tests were performed: monocular visual acuity in distance and near vision, visual field, stereopsis, contrast sensitivity, intraocular pressure and balance test binocular. Subsequently, a questionnaire was carried out on the patient’s driving data and ocular antecedents. Results: 74.5% of the drivers used glasses to drive, of which 61.5% used progressive glasses. However, 39.4% reported having difficulties seeing well. The mean visual acuity in the distance and near was 0.93 ± 0.13 and 0.94 ± 0.13, respectively. Significant differences have been found in accident risk based on visual acuity (p < 0.001). But no significant differences have been found in terms of visual field, stereopsis, contrast sensitivity, binocular balance and intraocular pressure (p > 0.05). Conclusion: Vision appears to play a key role in driving and a good visual assessment is recommended for early detection of visual problems that may affect road safety. A study with a larger sample size would be necessary to confirm the results of this pilot study.

Driving Skills Tested on Simulator After Strabismus Surgery: A Prospective Study

Purpose

The sense of vision is responsible for 90% of the information obtained by the motorist. Improvement in binocular visual acuity (VA) and visual field (VF) achieved after strabismus surgery could have beneficial effects on driving. Our study sought to identify functional improvements (VA and VF) and improvements in driving ability following strabismus surgery.

Methods

In a prospective cohort study, the following parameters are analyzed before and 3 months after strabismus surgery: simulated driving performance (including eye movements and actions on vehicle control), binocular VA, binocular VF, and self-confidence during driving.

Results

Twenty patients participated in the study. The mean preoperative logMAR binocular VA and stereopsis do not significantly differ from the postoperative. The mean Esterman VF score increases from 91.3 (±17.2) preoperatively to 96.9 (±13.9) postoperatively (P = 0.045). The mean self-confidence directed at driving scores decreases from 20.5 (±10.3) points before surgery to 11.0 (±6.0) points after surgery (P < 0.001). The distance at which the road signs are identified is significantly higher after surgery. The average speed of the vehicle and the speed near the targets (30 m) increase significantly after strabismus surgery. A significant decrease in ocular movements near targets is also observed. The number of brake pedal depressions and the rate of brake pedal depressions slightly decrease after surgery.

Conclusions

This study demonstrates the potential beneficial effects of strabismus surgery on driving ability, with significant improvements in self-confidence during driving, VF, and driving on a simulator.

Translational Relevance

This was the first study to use a driving simulator in strabismus.