Visual risk factors for driving difficulty among older drivers

Visual Function and Driving Performance Under Different Lighting Conditions in Older Drivers: Preliminary Results From an Observational Study

BACKGROUND

Age-related vision changes significantly contribute to fatal crashes at night among older drivers. However, the effects of lighting conditions on age-related vision changes and associated driving performance remain unclear.

OBJECTIVE

This pilot study examined the associations between visual function and driving performance assessed by a high-fidelity driving simulator among drivers 60 and older across 3 lighting conditions: daytime (photopic), nighttime (mesopic), and nighttime with glare.

METHODS

Active drivers aged 60 years or older participated in visual function assessments and simulated driving on a high-fidelity driving simulator. Visual acuity (VA), contrast sensitivity function (CSF), and visual field map (VFM) were measured using quantitative VA, quantitative CSF, and quantitative VFM procedures under photopic and mesopic conditions. VA and CSF were also obtained in the presence of glare in the mesopic condition. Two summary metrics, the area under the log CSF (AULCSF) and volume under the surface of VFM (VUSVFM), quantified CSF and VFM. Driving performance measures (average speed, SD of speed [SDspeed], SD of lane position (SDLP), and reaction time) were assessed under daytime, nighttime, and nighttime with glare conditions. Pearson correlations determined the associations between visual function and driving performance across the 3 lighting conditions.

RESULTS

Of the 20 drivers included, the average age was 70.3 years; 55% were male. Poor photopic VA was significantly correlated with greater SDspeed (r=0.26; P<.001) and greater SDLP (r=0.31; P<.001). Poor photopic AULCSF was correlated with greater SDLP (r=-0.22; P=.01). Poor mesopic VUSFVM was significantly correlated with slower average speed (r=-0.24; P=.007), larger SDspeed (r=-0.19; P=.04), greater SDLP (r=-0.22; P=.007), and longer reaction times (r=-0.22; P=.04) while driving at night. For functional vision in the mesopic condition with glare, poor VA was significantly correlated with longer reaction times (r=0.21; P=.046) while driving at night with glare; poor AULCSF was significantly correlated with slower speed (r=-0.32; P<.001), greater SDLP (r=-0.26; P=.001) and longer reaction times (r=-0.2; P=.04) while driving at night with glare. No other significant correlations were observed between visual function and driving performance under the same lighting conditions.

CONCLUSIONS

Visual functions differentially affect driving performance in different lighting conditions among older drivers, with more substantial impacts on driving during nighttime, especially in glare. Additional research with larger sample sizes is needed to confirm these results.

Quality of life assessment for nuclear, cortical, posterior subcapsular patients before and after cataract surgery

PURPOSE

The impact of visual outcomes of cataract surgery can be measured using a questionnaire. The aim of our study was to evaluate how patient quality of life changes after cataract surgery and if there are differences between the responses of patients with nuclear, cortical, and posterior subcapsular cataracts, which has not been studied before.

METHOD

We studied 210 cataract patients who were divided into 3 cataract groups based on their cataract type: nuclear (n = 80), cortical (n = 70), and posterior subcapsular (PSC) (n = 60). The patients completed the Visual Function Index (VF-14) questionnaire before, 2 weeks and 1 month after bilateral cataract surgery. The results were analysed using one-way ANOVA (significance level 5 %) and were compared over time and between the cataract groups.

RESULTS

Before the cataract surgery, cortical cataract patients had the lowest questionnaire score compared to nuclear and posterior subcapsular cataract groups (p = 0.08). After cataract surgery, cortical cataract patients experienced the greatest improvement in near distance daily activities, while PSC cataract patients experienced the greatest improvement in far distance daily activities (p = 0.38). Before surgery, nuclear cataract patients had the highest questionnaire scores compared to the other cataract groups (p = 0.08).

CONCLUSION

At the 1 month follow-up, there were no statistically significant differences in questionnaire scores between the cataract groups for any of the questions. Overall, cortical cataract patients showed a trend to experience the greatest subjective improvement in quality of life after cataract removal, followed by nuclear and posterior subcapsular patients.

Older Drivers' Attitudes and Preferences about Instrument Cluster Designs in Vehicles Revealed by the Dashboard Questionnaire

Background

Older drivers are a rapidly growing demographic group worldwide; many have visual processing impairments. Little is known about their preferences about vehicle instrument cluster design.

Methods

We evaluated the psychometric properties of a questionnaire on "dashboard" design for a population-based sample of 1000 older drivers. Topics included gauges, knobs/switches, and interior lighting; items were statements about their visual design. Response options used a Likert-scale ("Definitely True" to "Definitely False"). Factor and Rasch analyses identified underlying subscales.

Results

Driver responses revealed four thematic subscales fitting the Rasch model: cognitive processing, lighting, pattern recognition, and obstructions. Internal consistency of subscales was acceptable (0.70-0.87); all possessed a sufficiently unidimensional structure. Opportunities for improvement were identified (item scope, category ordering, discrimination of respondents' perception levels).

Conclusions

Assessment of motor vehicle dashboard preferences indicated cognitive processing, lighting, pattern recognition, and obstructions are areas relevant to older drivers. Future work will examine the relationship between older drivers' visual function (e.g., contrast sensitivity, visual processing speed) and their design preferences as revealed by the Dashboard Questionnaire, with the aim to optimize instrument cluster displays for older drivers.

Comparison of visual requirements and regulations for obtaining a driving license in different European countries and some open questions on their adequacy

We reviewed the current state of knowledge regarding visual function and its suitability as part of medical examinations for driving licenses. We focused only on Group 1 drivers. According to previous studies, visual acuity, which is the most common test, is weakly associated with a higher risk of road accidents, with a greater role of visual field. The inclusion of the visual field test in medical examinations is therefore important, but the actual limit value is still unclear and further research in specific situations is needed. Color vision impairment was not found a threat to traffic safety. Contrast sensitivity decreases with age and is affected by abnormal eye conditions. Resulting glare can lead to an increased risk of traffic accidents during night driving in the elderly and others with conditions that impair contrast sensitivity. However, the universal cut-off limits have not been established either. The current European Union (EU) regulations therefore reflect minimum common denominator across the member states which may not entirely translate to optimal driving safety. Due to these open questions, standardized testing in simulators or on polygons that simulate real life conditions would be needed to better determine safe limits of visual function in different conditions. As there is a need to have better standardization across Europe regarding the requirements and rules regarding driving licenses in European countries, we first analyzed existing rules and compared them with each other, also in terms of deviations from the EU directive itself. We reviewed the literature in this field and prepared proposals for a more optimal regulation of the rules in the future. Particular attention is paid to the new method of examining the visual field that was created to respect the European directive. The paper can serve as a basis of information for research teams to design further protocols, as it gathers research findings to date on the importance and impact of various visual functions on driving safety, as well as a starting point for a debate on revising existing rules for obtaining and maintaining licenses, as it compares the current regulations in European countries and differences between them.

Prevalence of Reduced Vision among UK Elderly Drivers: The Bridlington Eye Assessment Project (BEAP)—A Cross-Sectional Study

Self-assessment of driving fitness is mandatory in the United Kingdom. A paucity of data on visual function among drivers exists. We report prevalence of elderly drivers below legal visual acuity (VA) standard from a population study (The Bridlington Eye Assessment Project (BEAP)) conducted from 2002 to 2006. All residents aged ≥65 years were invited, 3459 undergoing structured interviews/ophthalmic examinations. Driving status was recorded, VA measured, and visual field (VF) testing performed. Outcomes were prevalence and characteristics of drivers below VA legal standard and prevalence of bilateral VF defects. Conditions causing reduced VA were explored and those with treatable conditions allowing visual improvement identified. Duration since last optometry review was recorded. Associations were explored using unpaired t -tests for continuous and chi-squared for discrete variables. Logistic regression was used for multivariate analysis and to determine odd ratios in the final adjusted model. Statistical analysis was performed using Stata 14.0 (Stata Corp, Tx). Within this sample, 7.1% (95% CI 6.0–8.3) of drivers fell below the VA legal driving standard (6/12) in their better eye, with 20% not having seen an optometrist for 2 years, including 8.2% who had not attended for over 5 years. The percentage of drivers falling below the VA minimum increases with age reaching 22.8% (95% CI 13.7–35.3) among those aged 85–89 years. 7.2% (95% CI 6.2–8.6) of drivers had bilateral visual field defects. 93% of drivers with reduced VA below legal standard had a cataract, refractive error or both in at least one eye. Significant numbers of elderly drive with VA below legal standard, most having easily correctable causes. Poor attendance with optometrists appears commonplace. Public education raised awareness of legal driving standards and encouraged compliance are required. Regular eye tests, appropriate refractive correction, and cataract surgery when needed should be encouraged.

Speed management across road environments of varying complexities and self-regulation behaviors in drivers with cataract

Evidence suggests that drivers with cataract self-regulate their driving, but there is a lack of objective information. This study compared speed behavior in older drivers with and without cataract and how the parameter is influenced by road traffic complexity and driver characteristics. The study included 15 drivers with cataract and a control group of 20 drivers. Visual status was assessed using visual acuity, contrast sensitivity, and intraocular straylight. Speed management was studied using a driving simulator. Driving difficulty and self-regulation patterns were evaluated by means of the Driver Habits Questionnaire (DHQ). The cataract group showed a significant decrease in visual function in all the parameters evaluated (p < 0.05). These drivers tended to drive at lower speeds than the control group. Road characteristics, gender, and intraocular straylight in the better eye were identified as significant predictors of speed management. Drivers with cataract experience greater driving difficulty, particularly when driving at night (p < 0.05). Drivers with cataract reduce their driving speed more than older drivers without visual impairment. The straylight parameter may be a good indicator of each driver's subjective perception of their own visual ability to drive. This work helps shed light on the mechanisms through which age-related visual impairment influences driving behavior.

Vision, Driving Exposure, and Collisions in Bioptic Drivers

SIGNIFICANCE

Lack of knowledge regarding the mileage driven by drivers with low vision who use bioptic telescopes could obscure the relationship between vision and road safety. This study provides data suggesting that worse vision is correlated with less mileage driven but more collisions per mile in bioptic drivers.

PURPOSE

The purpose of this study was to determine whether vision or demographic factors predict mileage driven in bioptic drivers and per-mile motor vehicle collision rate and also to compare the collision rate of bioptic drivers with previous estimates for the general population.

METHODS

Driver data were collected retrospectively from clinic records. Collision data were collected from the Ohio Bureau of Motor Vehicles database. Subjects were also asked to estimate their yearly mileage. Regression models were used to investigate relationships between vision and collision rates.

RESULTS

Seventy-three licensed Ohio bioptic drivers (36 male) were included. Mean ± standard deviation age was 51 ± 16 years. Mean logMAR visual acuity was 0.67 (approximately 20/100). Mean log contrast sensitivity was 1.57. Mean reported annual mileage was 9746. Age, sex, and previous (nonbioptic) driving experience were not associated with mileage. LogMAR visual acuity was inversely related to mileage (P = .02), and contrast sensitivity (P = .01) and horizontal visual field (P = .02) were directly associated with mileage. Visual acuity (P = .02) and visual field (P = .005), but not contrast sensitivity (P = .19), were associated with number of collisions.

CONCLUSIONS

Visual acuity, visual field, and contrast sensitivity were associated with driving exposure in bioptic drivers (with drivers with poorer vision reporting lower annual mileage), and poorer visual acuity and visual field were associated with more collisions. The per-mile collision rate for bioptic drivers was within the range of that previously reported for fully sighted drivers, although higher than would be expected for fully sighted drivers of similar age distribution.

Preoperative Care for Cataract Surgery: The Society for Ambulatory Anesthesia Position Statement

Cataract surgeries are among the most common procedures requiring anesthesia care. Cataracts are a common cause of blindness. Surgery remains the only effective treatment of cataracts. Patients are often elderly with comorbidities. Most cataracts can be treated using topical or regional anesthesia with minimum or no sedation. There is minimal risk of adverse outcomes. There is general consensus that cataract surgery is extremely low risk, and the benefits of sight restoration and preservation are enormous. We present the Society for Ambulatory Anesthesia (SAMBA) position statement for preoperative care for cataract surgery.

Midlife Vision Impairment and Cognitive Function in Later Life: The Study of Women's Health Across the Nation, Michigan Cohort

BACKGROUND

In older adults, vision impairment (VI) is associated with worse cognitive function. However, the relationship between midlife vision and future cognitive function remains unknown.

METHODS

The Study of Women's Health Across the Nation, Michigan site, is a longitudinal cohort of midlife women aged 42-52 years at baseline. Presenting Titmus visual acuity (VA) in the better-seeing eye was assessed at baseline and categorized as no or mild VI (VA ≥20/60), or moderate or worse VI (VA <20/60). Cognitive function was measured 8 times over 15 years using the East Boston Memory Test immediate (EBMTi) and delayed (EBMTd) recall and the Digit Span Backwards (DSB) test. Linear mixed models with a random intercept and slope for age were constructed to detect associations between VI at baseline and future repeated measures of cognitive function, adjusting for age, race, education, financial strain, alcohol use, and tobacco use.

RESULTS

About 394 women aged 42-52 at baseline with a maximum follow-up of 20 years were included in this analysis. After covariate adjustment, moderate or worse VI was associated with lower EMBTi (β = -0.56, p = .012), EBMTd (β = -0.60, p = .009), and DSB (β = -0.84, p = .04). While we detected significant associations between VI and levels of cognitive function scores, rates of cognitive decline as individuals aged did not vary by VI status.

CONCLUSION

Moderate or worse VI, assessed during midlife, was associated with lower scores on measures of cognitive function over a 15-year period during which women transitioned from midlife to older adulthood.

Estimating time-to-contact when vision is impaired

Often, we have to rely on limited information when judging time-to-contact (TTC), as for example, when driving in foul weather, or in situations where we would need reading glasses but do not have them handy. However, most existing studies on the ability to judge TTC have worked with optimal visual stimuli. In a prediction motion task, we explored to what extent TTC estimation is affected by visual stimulus degradation. A simple computer-simulated object approached the observer at constant speed either with clear or impaired vision. It was occluded after 1 or 1.5 s. The observers extrapolated the object's motion and pressed a button when they thought the object would have collided with them. We found that dioptric blur and simulated snowfall shortened TTC-estimates. Contrast reduction produced by a virtual semi-transparent mask lengthened TTC estimates, which could be the result of distance overestimation or speed underestimation induced by the lower contrast or the increased luminance of the mask. We additionally explored the potential influence of arousal and valence, although they played a minor role for basic TTC estimation. Our findings suggest that vision impairments have adverse effects on TTC estimation, depending on the specific type of degradation and the changes of the visual environmental cues which they cause.

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.

Left Turns by Older Drivers With Vision Impairment: A Naturalistic Driving Study

BACKGROUND AND OBJECTIVES

Older drivers are overrepresented in collisions at intersections while making left turns across oncoming traffic. Using naturalistic driving methods, we evaluated the association between vision impairment and their left-turn characteristics.

RESEARCH DESIGN AND METHODS

In this prospective, observational study, vision impairment as defined by visual acuity, contrast sensitivity, visual processing speed, visual field sensitivity, and motion perception was assessed in drivers ≥70 years old. Data acquisition systems were installed in their personal vehicles recording video and vehicle kinematics. Driving during everyday life was recorded for 6 months. Data analysts evaluated a temporal data window surrounding randomly selected left turns at 4-way intersections. Left-turn traversals and turning behavior were evaluated in terms of age-adjusted associations with vision impairment.

RESULTS

The sample consisted of 151 older drivers. The number of turns studied was 473; 265 turns were rated as unsafe traversals, and 201 as problematic turning behavior. Drivers with slowed visual processing speed and visual field impairment were less likely to exhibit unsafe traversals (p < .05); those with worse contrast sensitivity, slowed visual processing speed, and visual field impairment were less likely to exhibit problematic turning behavior (p < .05).

DISCUSSION AND IMPLICATIONS

Using naturalistic driving, our study suggests older drivers with vision impairment exhibit better performance in making left turns than those without deficits, which contradicts older driver studies on left turns using driving simulators and on-road driving evaluations. Our findings suggest more cautious and self-regulatory behavior, which are consistent with older visually impaired drivers' commonly expressed concerns about their driving difficulties.

Effect of Initial Aflibercept, Laser, or Observation on Low-Contrast Visual Acuity in Eyes With Diabetic Macular Edema and Good Vision: Ancillary Study Within a Randomized Clinical Trial

Purpose

To describe 2.5% low-contrast visual acuity (VA) among eyes with good vision despite center-involved diabetic macular edema and compare changes after initial management with aflibercept, laser, or observation.

Methods

This was an ancillary study within a multicenter randomized clinical trial (DRCR Retina Network Protocol V). Participants had diabetes and 1 study eye with center-involved diabetic macular edema and a VA of 20/25 or better randomly assigned to aflibercept (n = 112), focal/grid laser (n = 146), or observation (n = 129). Eyes in the laser and observation groups received aflibercept if VA met prespecified worsening criteria.

Results

Participants had median age of 60 years, 37% were female and 70% were non-Hispanic White. At baseline, the mean ± standard deviation (SD) high-contrast VA was 85.2 ± 3.6 letters (Snellen equivalent 20/20), mean ± SD 2.5% low-contrast VA was 47.6 ± 18.9 letters (Snellen equivalent 20/125), and low-contrast VA letter score was 2 SDs or more below the age-specific normative values in 23%. At 2 years, the mean change ± SD in low-contrast VA in the aflibercept, laser, and observation groups was 2.7 ± 20.1, –2.0 ± 19.6, and –3.1 ± 20.8 letters (adjusted difference, aflibercept vs. laser, 5.3 [95% confidence interval, –0.2 to 10.8], P = 0.06; aflibercept vs. observation, 5.5 [95% confidence interval –0.2 to 11.2], P = 0.06; and laser vs. observation, 0.2 [95% confidence interval –4.6 to 5.0], P = 0.94).

Conclusions

There was no significant difference between treatment groups in low-contrast VA change from baseline to 2 years. Considering the range of the 95% confidence intervals, however, the study may have been underpowered to detect a clinically meaningful benefit between treatment groups.

Translational Relevance

Low-contrast VA, an important visual function, is decreased in eyes with diabetic macular edema.

The Effects of an In-vehicle Collision Warning System on Older Drivers' On-road Head Movements at Intersections

With age might come a decline in crucial driving skills. The effect of a collision warning system (CWS) on older drivers' head movements behavior at intersections was examined. Methods: Twenty-six old-adults, between 55 and 64 years of age, and 16 Older drivers between 65 and 83 years of age, participated in the study. A CWS (Mobileye Inc.) and a front-back in-vehicle camera (IVC) were installed in each of the participants' own vehicles for 6 months. The CWS was utilized to identify unsafe events during naturalistic driving situations, and the IVC was used to capture head direction at intersections. The experimental design was conducted in three phases (baseline, intervention, and carryover), 2 months each. Unsafe events were recorded by the CWS during all phases of the study. In the second phase, the CWS feedback was activated to examine its effect on drivers' head movement' behavior at intersections. Results: Older drivers (65+) drove significantly more hours in total during the intervention phase (M = 79.1 h, SE = 10) than the baseline phase (M = 39.1 h, SE = 5.3) and the carryover phase (M = 37.7 h, SE = 5.4). The study revealed no significant differences between the head movements of older and old-adult drivers at intersections. For intersection on the left direction, a significant improvement in drivers' head movements' behavior was found at T-junctions, turns and four-way intersections from phase 1 to phase 3 (p < 0.01), however, two intersection types presented a decrease along the study phases. The head movements' behavior at roundabouts and merges was better at phase 1 compared to phase 3 (p < 0.01). There was no significant reduction of the mean number of CWS unsafe events across the study phases. Conclusions: The immediate feedback provided by the CWS was effective in terms of participants' head movements at certain intersections but was harmful in others. However, older drivers drove many more hours during the active feedback phase, implying that they trusted the system. Therefore, in the light of this complex picture, using the technological feedback with older drivers should be followed with an additional mediation or follow-up to ensure safety.

The short-term effects of artificially-impaired binocular vision on driving performance

Appropriate visual function is paramount to ensuring adequate driving performance and road safety. Here, we examined the influence of sudden artificially-impaired binocular vision on driving performance using a car simulator. Twenty-four young drivers (mean age 22.42 ± 3.19 years) drove under three different visual conditions (natural driving, monocular blur, and monocular occlusion) through three different traffic environments with low, medium, and high levels of complexity (highway, rural, and city, respectively). We assessed their driving performance, perceived level of task complexity, and subjectively-experienced road safety. Furthermore, as a manipulation check, we also evaluated the drivers' cardiac vagal responses, as a well-known index of task complexity. The sudden deterioration of binocular vision caused unsafe driving behaviours (distance out of the road and maximum breaking intensity) in the most complex traffic environments. Specific self-regulatory strategies (i.e. increased cardiac vagal responses) and subjective responses corroborated these results. Practitioner summary: This study provides evidence that the sudden deterioration of binocular vision has a detrimental effect on simulated driving performance. Our analysis of cardiovascular functioning shows that drivers adopt self-regulatory strategies when their binocular vision functioning is compromised. Abbreviations: VA: visual acuity; BV: binocular vision; HRV: heart rate variability; NASA: TLX: NASA-Task Load Index; SSS: Stanford Sleepiness scale; RMSSD: root mean square of successive difference; HF: high-frequency.

Novel computer-based assessments of everyday visual function in people with age-related macular degeneration

PURPOSE

To test the hypothesis that the performance in novel computer-based tasks of everyday visual function worsens with disease severity in people with non-neovascular age-related macular degeneration.

METHODS

Participants with and without non-neovascular age-related macular degeneration (≥60 years, minimum logMAR binocular visual acuity 0.7) performed a series of standard visual function tests and two novel computer-based tasks. In a visual search task, participants had to locate an image of a single real-world object within an array of 49 distractor images. Next, in a series of simulated dynamic driving scenes, participants were asked to identify one or two approaching real-world road signs and then select these road signs from four options. Outcome measures were median response times and total correct responses.

RESULTS

Forty-nine participants had no macular disease (n = 11), early/intermediate age-related macular degeneration (n = 16) or geographic atrophy (n = 22). Groups were age-similar with median (interquartile range) logMAR visual acuity of 0.00 (-0.08,0.12), 0.13 (-0.08,0.70) and 0.32 (0.12,0.70) respectively. Median (interquartile range) visual search response times were 1.9 (1.0,2.4), 1.8 (1.1,3.7) and 2.4 (1.2,6.0) seconds respectively. Median (interquartile range) road sign response times (single road signs) were 1.2 (0.4,1.7), 1.5 (0.9,2.8) and 1.8 (1.0,5.5) seconds respectively. Median (interquartile range) road sign response times (double road signs) were 1.7 (0.7,2.4), 2.3 (1.2,3.1) and 2.5 (1.7,6) seconds respectively. Participants with geographic atrophy recorded slower response times in all tasks and over 50% performed outside the normative limit for task performance. There were no significant differences between groups in total correct responses across all tasks.

CONCLUSIONS

In a novel computer-based assessment, people with increasing severity of age-related macular degeneration take longer to perform visual search of everyday objects and take longer to identify road signs than those with no age-related macular degeneration. These novel assessments could be useful as patient-relevant, secondary outcomes for clinical trials.

Older drivers' self-reported vision-related night-driving difficulties and night-driving performance

PURPOSE

To investigate associations between older drivers' perceived vision-related night-driving difficulties and night-time driving performance measured on a closed-road circuit.

METHODS

Participants included 26 older drivers (71.8 ± 6.3 years) who reported vision-related night-driving difficulties assessed with the vision and night driving questionnaire (VND-Q). High-contrast, photopic visual acuity (VA) and ratings of discomfort glare (de Boer scale) were also assessed. Night-time driving performance was measured on a closed-road circuit that involved recognition, hazard avoidance and lane-keeping tasks in the absence and presence of intermittent glare. Generalized linear mixed models investigated the relationship between VND-Q scores and overall driving performance scores, as well as with discomfort glare ratings and VA.

RESULTS

Greater levels of vision-related night-driving difficulties (VND-Q scores) were significantly associated with poorer night-driving performance (p = 0.003); the association was even stronger for driving performance in the presence of intermittent glare (p = 0.001). Reduced VA was associated with poorer night-driving performance (p = 0.022) but the association was weaker than for the VND-Q scores. In contrast, ratings of discomfort glare were not significantly associated with driving performance (p = 0.14).

CONCLUSION

The VND-Q was significantly associated with night-time driving performance and provides a useful instrument for assessing vision-related night-driving difficulties which can be incorporated into clinical vision assessments.

Brake time is correlated with lower extremity strength, dynamic balance and low-contrast sensitivity in unpredictable driving situations in elderly drivers compared with young drivers: A cross-sectional study

AIMS

To compare physical function, driving fitness and brake time of young and elderly drivers, and to identify the association of physical function and driving fitness with brake time in elderly drivers in predictable or unpredictable situations during driving.

METHODS

This study included 86 participants (50 men and 36 women), comprising 52 elderly drivers (age: 72.44 years, weight: 60.39 kg, height: 158.06 cm) and 34 young drivers (age: 26.53 years, weight: 63.74 kg, height: 153.65 cm), with a valid driver's license who drive at least once a week. Physical function was measured as upper and lower body flexibility and strength, dynamic balance and aerobic endurance. Driving fitness was measured as high- and low-contrast sensitivity, route planning, visualization of missing information, visual search with divided attention and visual information processing speed using the DrivingHealth® Inventory. Brake time and braking distance was evaluated as unpredictable and predictable driving situations.

RESULTS

Measurements of all categories, except lower extremity flexibility, endurance and high-contrast sensitivity, were significantly lower in elderly drivers than in young drivers. Brake time did not differ in predictable situations but was slower (P = 0.004) in elderly drivers in unpredictable situations. In elderly drivers, upper body strength (P = 0.036), dynamic balance (P < 0.001) and low-contrast sensitivity (P = 0.003) were associated with brake time in unpredictable driving situations.

CONCLUSIONS

In unpredictable situations, slower brake time in elderly drivers is associated with lower limb muscle strength, agility and low-contrast sensitivity. Therefore, for safe driving, these parameters should be considered as guidelines for maintaining the driving ability of elderly drivers and aging people. Geriatr Gerontol Int 2020; ••: ••-••.

Association of Photopic and Mesopic Contrast Sensitivity in older drivers with risk of motor vehicle collision using naturalistic driving data

Background

Older drivers have a crash rate nearly equal to that of young drivers whose crash rate is the highest among all age groups. Contrast sensitivity impairment is common in older adults. The purpose of this study is to examine whether parameters from the photopic and mesopic contrast sensitivity functions (CSF) are associated with incident motor vehicle crash involvement by older drivers.

Methods

This study utilized data from older drivers (ages ≥60 years) who participated in the Strategic Highway Research Program Naturalistic Driving Study, a prospective, population-based study. At baseline participants underwent photopic and mesopic contrast sensitivity testing for targets from 1.5–18 cycles per degree. Model fitting generated area under the log CSF (AULCSF) and peak log sensitivity. Participant vehicles were instrumented with sensors that captured continuous driving data when the vehicle was operating (accelerometers, global positioning system, forward radar, 4-channel video). They participated for 1–2 years. Crashes were coded from the video and other data streams by trained analysts.

Results

The photopic analysis was based on 844 drivers, and the mesopic on 854 drivers. Photopic AULCSF and peak log contrast sensitivity were not associated with crash rate, whether defined as all crashes or at-fault crashes only (all p > 0.05). Mesopic AULCSF and peak log sensitivity were associated with an increased crash rate when considered for all crashes (rate ratio (RR): 1.36, 95% CI: 1.06–1.72; RR: 1.28, 95% CI: 1.01–1.63, respectively) and at-fault crashes only (RR: 1.50, 95% CI: 1.16–1.93; RR: 1.38, 95% CI: 1.07–1.78, respectively).

Conclusions

Results suggest that photopic contrast sensitivity testing may not help us understand future crash risk at the older-driver population level. Results highlight a previously unappreciated association between older adults’ mesopic contrast sensitivity deficits and crash involvement regardless of the time of day. Given the wide variability of light levels encountered in both day and night driving, mesopic vision tests, with their reliance on both cone and rod vision, may be a more comprehensive assessment of the visual system’s ability to process the roadway environment.

Bisphenol A exposure inhibits contrast sensitivity in cats involving increased response noise and inhibitory synaptic transmission

Contrast sensitivity (CS) is one of the primary fundamental factors determining how well we can see, and it directly influences object recognition. Whether bisphenol-A (BPA, an environmental xenoestrogen) can perturb contrast detection in the visual system has yet to be elucidated. In the present study, we analyzed CS of single neurons in the primary visual cortex (area 17, A17) of cats before and after BPA exposure using a multiple-channel recording technique. The results showed that CS of A17 neurons was markedly depressed with an increased contrast threshold after two hour of intravenous BPA administration, which had a positive correlation with decreased firing rates of A17 neurons. Additionally, responses of these neurons presented an overt increase in the trial-to-trail response variability (a kind of neuronal noise), which could disturb the information-filtering function of single neurons. We also found that neuronal CS in the visual relay station was not disturbed after BPA administration, which rules out the contribution of CS alteration in the optical pathway. Importantly, acute BPA treatment obviously increased the inhibitory innervation to the visual pyramidal neurons. This implies that alteration of intracortical inhibitory regulation contributes to the compromised contrast detection in the visual system after BPA treatment.

Solar Glare Vulnerability Analysis of Urban Road Networks—A Methodology

Solar glare on roads is responsible for momentaneous deterioration of a driver’s view, interfering with driving capacity and causing accidents. The situation of a driver being affected by solar glare on a road is a spatial-temporal variable, since it depends not only on the time of the day and the day of the year, which are determinant for the local Sun position (temporal factors), but also on the local slope and azimuth of the road in the driven direction (spatial factors). The present work describes a method for producing road glare maps along a road network, as well as retrieving glare information from urban roads so that solar glare vulnerability can be easily accessed. Input data are a 1m resolution Digital Surface Model from Light Detection and Ranging data and the road network. Spatial parameters are processed in a Geographic Information System environment. The Urban Glare Algorithm detects glare and outputs temporal matrices and glare maps. Shadows cast by buildings and trees are considered as well as the driver’s eyes height. The method is tested in an area of Lisbon (Portugal). This work is a contribution to road safety systems implementation and constitutes a relevant basis for warning drivers of glare through car navigation systems.

Equal Protection, the ADA, and Driving with Low Vision: A Legal Analysis

This article describes federal and state laws that affect the opportunity of people with low vision to drive and to obtain driver's licenses. Discrimination against individuals with low vision is discussed in the context of equal protection and the Americans with Disabilities Act. A review of relevant case law and implications for drivers with low vision are presented.

Effects of multitasking and intention-behaviour consistency when facing yellow traffic light uncertainty

We examined the effects of multitasking on resolving response bistability to yellow traffic lights, using the performance metrics of reaction time and stopping frequency. We also examined whether people's actual behaviours, measured by implicit foot pedal responses, differed from their intentions related to these factors, as measured by explicit verbal commands. In a dual-task paradigm, participants responded to random traffic light changes, presented over a static background photograph of an intersection, using either foot pedals or verbal commands, while simultaneously identifying spoken words as either "animals" or "artefacts" via button pressing. The dual-task condition was found to prolong reaction times relative to a single-task condition. In addition, verbal commands were faster than the foot pedal responses, and conservativeness was the same for both types of responses. A second experiment, which provided a more dynamic simulation of the first experiment, confirmed that conservativeness did not differ between verbal commands and foot pedal responses. We conclude that multitasking affects a person's ability to resolve response bistability to yellow traffic lights. If one considers that prolonged reaction times reduce the amount of distance available to safely stop at intersections, this study underscores how multitasking poses a considerable safety risk for drivers approaching a yellow traffic light.

Working conditions, health and retirement intentions: a case study of truck drivers

Purpose

Being a professional truck driver implies prolonged exposure to physical and psychosocial risks, which can affect health and work ability in the short and long term. The purpose of this paper is to examine the role of working conditions in truck drivers’ perceived health and retirement intentions in a Portuguese transportation company.

Design/methodology/approach

Using ergonomic work analysis (EWA), this study incorporates document analysis, observation and 16 interviews. Content analysis is applied to interviews’ transcripts.

Findings

In line with previous research, drivers acknowledged their activity as physically demanding (e.g. static postures, repetitive movements, heavy lifting) and psychologically demanding (e.g. high time pressure, lack of control, lack of work–family balance). Despite that, drivers report themselves to be in good health, with only some complaints related to back and knee pain. However, hard working conditions associated with ageing can contribute to gradual health deterioration, leading them to desire to retire before the legal retirement age.

Practical implications

The company can promote drivers’ health by creating a unit to provide psychosocial support and career orientation, improving the mentoring programme, and investing in training on occupational risk prevention.

Originality/value

This study is the first to use EWA to examine the impact of the complex relationship between truck drivers’ work and health in their retirement intentions, adopting a temporal perspective.

Correlation between observation task performance and visual acuity, contrast sensitivity and environmental light in a simulated maritime study

PURPOSE

To examine the relevance of visual acuity (VA) and index of contrast sensitivity (ICS) as predictors for visual observation task performance in a maritime environment.

METHODS

Sixty naval cadets were recruited to a study on observation tasks in a simulated maritime environment under three different light settings. Their ICS were computed based on contrast sensitivity (CS) data recorded by Optec 6500 and CSV-1000E CS tests. The correlation between object identification distance and VA/ICS was examined by stepwise linear regression.

RESULTS

The object detection distance was significantly correlated to the level of environmental light (p < 0.001), but not to the VA or ICS recorded in the test subjects. Female cadets had a significantly shorter target identification range than the male cadets.

CONCLUSION

Neither CS nor VA were found to be significantly correlated to observation task performance. This apparent absence of proven predictive value of visual parameters for observation tasks in a maritime environment may presumably be ascribed to the normal and uniform visual capacity in all our study subjects.

Cross-sectional study assessing the addition of contrast sensitivity to visual acuity when testing for fitness to drive

OBJECTIVES

The aim of this study is to quantify the importance of loss of contrast sensitivity (CS) and its relationship to loss of visual acuity (VA), driving restrictions and daytime, on-road driving evaluations in drivers aged 70+.

DESIGN

A predictive cross-sectional study.

SETTING

Volunteer participants to a drivers' refresher course for adults aged 70+ delivered by the Swiss Automobile Club in western Switzerland from 2011 to 2013.

PARTICIPANTS

162 drivers, male and female, aged 70 years or older.

CLINICAL PREDICTORS

We used a vision screener to estimate VA and the The Mars Letter Contrast Sensitivity Test to test CS.

OUTCOMES

We asked drivers to report whether they found five driving restrictions useful for their condition; restrict driving to known roads, avoid driving on highways, avoid driving in the dark, avoid driving in dense traffic and avoid driving in fog. All participants also underwent a standardised on-road evaluation carried out by a driving instructor.

RESULTS

Moderate to severe loss of CS for at least one eye was frequent (21.0% (95% CI 15.0% to 28.1%)) and often isolated from a loss of VA (11/162 cases had a VA ≥0.8 decimal and a CS of ≤1.5 log(CS); 6.8% (95% CI 3.4% to 11.8%)). Drivers were more likely (R²=0.116, P=0.004) to report a belief that self-imposed driving restrictions would be useful if they had reduced CS in at least one eye. Daytime evaluation of driving performance seems limited in its ability to correctly identify difficulties related to CS loss (VA: R²=0.004, P=0.454; CS: R²=0.006, P=0.332).

CONCLUSION

CS loss is common for older drivers. Screening CS and referring for cataract surgery even in the absence of VA loss could help maintain mobility. Reduced CS and moderate reduction of VA were both poor predictors of daytime on-road driving performances in this research study.

The Social Context of Driving Cessation: Understanding the Effects of Cessation on the Life Satisfaction of Older Drivers and Their Social Partners

Older adults with vision loss and a friend or family member were interviewed over a 2-year period. We examined the effects of driving cessation on life satisfaction among older adults and a social contact. Drivers' use of public transportation was examined as a moderator. Driving cessation was associated with a decline in life satisfaction among social partners but not for the drivers. Drivers' use of public transportation at baseline moderated the effects of cessation on changes in well-being among social partners, but had little effect on the life satisfaction of the drivers. Life satisfaction was greater among the social partners of ex-drivers who used public transportation more frequently. The association between driving cessation and well-being should be studied in the context of older drivers' social networks. Infrastructure (e.g., subways and buses) that supports transportation needs plays an important role in mitigating the effects of cessation on older adults' social networks.

Implementation of a teaching programme to improve doctors' awareness of DVLA guidelines: a multicentre study

INTRODUCTION

Over half of the UK population holds a driver's licence. Driver and Vehicle Licensing Authority (DVLA) guidelines are available for conditions from most specialties. Despite this, no focused training occurs in the undergraduate or postgraduate setting. We evaluate the impact of a teaching programme to improve guideline awareness.

METHODS

A 25-point questionnaire was designed using the current DVLA guidelines. Five questions were included for the following fields: neurology, cardiology, drug and alcohol abuse, visual disorders and respiratory. This was distributed to doctors in training at five hospitals. Four weeks later, a single-session teaching programme was implemented. The questionnaire was redistributed. Preintervention and postintervention scores were compared using the Wilcoxon rank sum test.

RESULTS

139 preteaching and 144 post-teaching questionnaires were completed. Implementation of a single-session teaching programme significantly improved the knowledge of DVLA guidelines in all five areas explored. Median scores: neurology, preteaching 40%, post-teaching 100%, p<0.001; cardiology, 0%, 100%, p<0.001; drug and alcohol misuse, 0%, 100%, p<0.001; visual disorders, 40%, 100%, p<0.001; respiratory disorders, 20%, 100%, p<0.001; and overall, 28%, 92%, p<0.001.

CONCLUSIONS

Knowledge of DVLA guidelines among our cohort was poor. Implementation of a single-session teaching programme can significantly improve guideline knowledge and awareness, serving as a cost-effective intervention.

Attitudes: Mediators of the Relation between Health and Driving in Older Adults

Nous avons examiné les relations entre la santé perçue (p. ex., l’état de santé auto-évaluation) et des pratiques d’autorégulation de la conduite (p. ex., la fréquence de la conduite, l’evitement des situations de conduite difficiles) comme médiée par les attitudes et les perceptions de conduite (à savoir, le confort de conduite, les attitudes positif et négatif envers la conduite) dans les données recueillies pour 928 conducteurs âgés de 70 ans et plus inscrits à l’étude Candrive II. Nous avons observé que les attitudes spécifiques à la conduite (p. ex., le confort de conduite, les attitudes négatives envers la conduite) assurent la médiation des relations entre les symptômes de santé et les comportements de conduite auto-reglementés au début et au fil du temps. Seuls les attitudes négatives à l’égard de conduite ont mediés entièrement les relations entre les changements dans les symptômes perçus de la santé et les changements dans le comportement de conduite. Les symptômes perçus pour la santé influencent apparemment la probabilité d’éviter des situations difficiles de conduite par le biais de deux attitudes négatives initiales pour la conduite, ainsi que des changements dans les attitudes négatives au fil du temps. Comprendre les influences sur le comportement de conduite d’auto-réglementation seront bénéfiques lors de la conception des interventions visant à améliorer la sécurité des conducteurs âgés.

The SPARCS: a novel assessment of contrast sensitivity and its reliability in patients with corrected refractive error

PURPOSE

To explore the reliability of the Spaeth/Richman Contrast Sensitivity (SPARCS) test and to assess the contrast sensitivity (CS) distribution among subjects with various refractive errors.

METHODS

Cross-sectional study. Ninety-three individuals (182 eyes) with varying amounts of refractive error were included in this study and divided into six groups according to their spherical equivalent. CS was evaluated using Pelli-Robson (PR) and SPARCS assessments. Each eye was tested twice with both measurements. Outcomes included the correlations of PR and SPARCS scores, the test-retest agreement of the two measurements and the limits of agreement between tests of CS measurements. The distribution of CS among the six groups was compared.

RESULTS

Pearson correlation analysis showed statistically significant correlations between SPARCS and PR scores (p<0.001). Reliability analysis showed that SPARCS had better test-retest agreement than PR, with SPARCS exhibiting a higher intraclass coefficient (ICC=0.635). Bland-Altman plots showed that the mean difference of measurements was close to 0 for both CS measurements. Among the six refractive groups, there were no significant differences in CS scores with either measurement.

CONCLUSIONS

SPARCS appears to be a reliable assessment for CS. The difference in CS among myopes, emmetropes and hyperopes wearing their habitual correction was statistically insignificant in this study.

CLINICAL TRIAL NUMBER

NCT01300949, post results.

Older driver fitness-to-drive evaluation using naturalistic driving data

PROBLEM

As our driving population continues to age, it is becoming increasingly important to find a small set of easily administered fitness metrics that can meaningfully and reliably identify at-risk seniors requiring more in-depth evaluation of their driving skills and weaknesses.

METHOD

Sixty driver assessment metrics related to fitness-to-drive were examined for 20 seniors who were followed for a year using the naturalistic driving paradigm. Principal component analysis and negative binomial regression modeling approaches were used to develop parsimonious models relating the most highly predictive of the driver assessment metrics to the safety-related outcomes observed in the naturalistic driving data.

RESULTS

This study provides important confirmation using naturalistic driving methods of the relationship between contrast sensitivity and crash-related events.

PRACTICAL APPLICATIONS

The results of this study provide crucial information on the continuing journey to identify metrics and protocols that could be applied to determine seniors' fitness to drive.

A roadmap for interpreting the literature on vision and driving

Over the past several decades there has been a sharp increase in the number of studies focused on the relationship between vision and driving. The intensified attention to this topic has most likely been stimulated by the lack of an evidence basis for determining vision standards for driving licensure and a poor understanding about how vision impairment impacts driver safety and performance. Clinicians depend on the literature on vision and driving to advise visually impaired patients appropriately about driving fitness. Policy makers also depend on the scientific literature in order to develop guidelines that are evidence-based and are thus fair to persons who are visually impaired. Thus it is important for clinicians and policy makers alike to understand how various study designs and measurement methods should be interpreted so that the conclusions and recommendations they make are not overly broad, too narrowly constrained, or even misguided. We offer a methodological framework to guide interpretations of studies on vision and driving that can also serve as a heuristic for researchers in the area. Here, we discuss research designs and general measurement methods for the study of vision as they relate to driver safety, driver performance, and driver-centered (self-reported) outcomes.

Effects of shrinkage of the visual field through ageing on parking performance: a parametric manipulation of salience and relevance of contextual components

The Master Activation model of attention (Michael, Vairet, and Fernandez, Capture attentionnelle en vision: La saillance, la pertinence, et la balance cortico-sous-corticale. In: G. A. Michael (ed), Neuroscience cognitive de l'attention visuelle [Cognitive Neuroscience of Visual Attention], Solal, Marseille, pp. 165-201, 2007; Michael, Lété, and Ducrot, Trajectories of Attentional Development: An Exploration with the Master Activation Map Model, Developmental Psychology, 49:615-631, 2013) was used to study visual attention and driving behaviours of younger and older drivers while parking a car. The salience and the relevance of elements present in the parking environment were manipulated during parking manoeuvres. Different effects on manoeuvring were observed depending on driver characteristics such as age and the extent of the field of view (FV). It was found that the presence of a relevant element, such as a pedestrian, impaired parking performance only among older drivers with a narrower FV. The distinct effects of salience and relevance suggest that they had different statuses in attentional processing of manoeuvring drivers.

The Impact of Health Problems on Driving Status among Older Adults

OBJECTIVE

This study assesses the impact of health problems on driving status (current driver vs. ex-driver) among older adults to identify which of those health problems have the greatest individual and population impact on driving cessation.

METHODS

Data were from baseline and 5 year follow-up waves of a longitudinal survey of adults age 55 years and older (N=1,279). The impact of several health problems on driving status was assessed using a relative risk ratio and a population attributable risk percent. Analyses controlled for age, gender, and the presence of additional baseline health problems.

RESULTS

Many health conditions were not associated with driving cessation. Functional limitations, cognitive function, and measures of vision were significant predictors of driving cessation. Self-care functional limitations were associated with the highest risk for driving cessation, while visual function was associated with the highest attributable risks.

DISCUSSION

In order to effectively address healthy aging and mobility transitions, it is important to consider the implications of targeting individuals or populations who are most at risk for driving cessation. The risk ratio is relevant for evaluating individuals; the attributable risk is relevant for developing interventions in populations.

Association between vision impairment and driving exposure in older adults aged 70 years and over: a population-based examination

PURPOSE

To examine the relationship between vision impairment and driving exposure (amount of driving one does) in a population-based sample of older drivers and to examine to what extent cognitive status impacts this relationship.

METHODS

Enrollees consisted of a population-based sample of older adults from Alabama who were ≥70 years old, held a current driver's license, and had driven within the last 3 months. Three aspects of visual function were measured under binocular conditions - habitual distance visual acuity, contrast sensitivity and visual processing speed. General cognitive status was assessed with the mini-mental status examination. Driving exposure was estimated by the Driving Habits Questionnaire that asked about the number of miles, places, trips and days driven per week.

RESULTS

Drivers with impaired contrast sensitivity exhibited reduced annual mileage, and a decreased number of places and trips driven per week compared to those with normal contrast sensitivity, even after adjustment for other factors. Slowed visual processing speed was associated with reduced number of days driven per week after adjustment. Visual acuity deficit was not associated with changes in driving exposure. Cognitive status did not impact any of the associations between vision impairment and driving exposure.

CONCLUSION

Older drivers with contrast sensitivity impairment exhibit reduced driving exposure in terms of number of trips and places they drive per week, as well as decreased annual mileage. These apparent self-regulatory practices should be viewed as adaptive because contrast sensitivity impairment elevates motor vehicle collision (MVC) risk and reduction in driving exposure can reduce MVC risk.

Documentation and reimbursable for driver rehabilitation services

Driving is the method of choice to maintain independent community mobility for most older adults. Therefore, occupational therapy practitioners need to evaluate and provide intervention for driver rehabilitation services. Since reimbursement is often seen as a barrier to providing these services, this paper underscores the value of occupational therapy practitioners providing driver rehabilitation services. Appropriate documentation and guidelines for reimbursement from Medicare are addressed with examples of how occupational therapy driver rehabilitation services can be funded by third party payers.

Assessment of capacity in an aging society

Over the past 40 years, the assessment and scientific study of capacity in older adults has emerged as a distinct field of clinical and research activity for psychologists. This new field reflects the convergence of several trends: the aging of American society, the growing incidence and prevalence of dementia, and the patient rights, deinstitutionalization, and disability rights movements. Because of these forces, capacity issues now permeate the fabric of everyday life, whether in the form of guardianship petitions, questions of capacity to consent to treatment, the ability to make a new will, or participation in human research. In seeking to resolve these issues, families, clinicians, and legal professionals increasingly turn to psychologists to assess a capacity and to provide empirically supported judgments that properly balance autonomy and protection for the individual. Psychologists have taken a leading role in the development of functional assessment instruments that measure important aspects of the capacity construct. In addition, psychology has been a major contributor to the scientific study of capacity. In collaboration with colleagues from medicine and law, psychologists have articulated crucial theoretical frameworks that integrate legal, clinical, and ethical dimensions of the capacity problem. This article focuses on the evolution of theory, law, science, and practice in the evaluation of capacity in older adults and its recent culmination in a series of interdisciplinary handbooks sponsored by the American Psychological Association and the American Bar Association.

Driver self-regulation and depressive symptoms in cataract patients awaiting surgery: a cross-sectional study

BACKGROUND

Cataract is an extremely common visual condition of ageing. Evidence suggests that visual impairment influences driving patterns and self-regulatory behavior among older drivers. However, little is known about the psychological effects of driver self-regulation among older drivers. Therefore, this study aimed to describe driver self-regulation practices among older bilateral cataract patients and to determine the association between self-regulation and depressive symptoms.

METHODS

Ninety-nine older drivers with bilateral cataract were assessed the week before first eye cataract surgery. Driver self-regulation was measured via the Driving Habits Questionnaire. Depressive symptoms were assessed using the 20-item Center for Epidemiological Studies Depression Scale. Visual, demographic and cognitive data were also collected. Differences between self-regulators and non self-regulators were described and linear regression modeling used to determine the association between driver self-regulation and depressive symptoms score.

RESULTS

Among cataract patients, 48% reported self-regulating their driving to avoid at least one challenging situation. The situations most commonly avoided were driving at night (40%), on the freeway (12%), in the rain (9%) and parallel parking (8%). Self-regulators had significantly poorer contrast sensitivity in their worse eye than non self-regulators (p = 0.027). Driver self-regulation was significantly associated with increased depressive symptoms after controlling for potential confounding factors (p = 0.002).

CONCLUSIONS

Driver self-regulation was associated with increased depressive symptoms among cataract patients. Further research should investigate this association among the general older population. Self-regulation programs aimed at older drivers may need to incorporate mental health elements to counteract unintended psychological effects.

Quantifying age-related differences in visual-discrimination capacity: drivers with and without visual impairment

The aim of this study is to examine the effects of aging as well as visual impairment on retinal-image quality and visual performance in drivers. We use a new visual test called Halo v1.0 software for quantifying the discrimination capacity, an important visual function for evaluating the visual disturbances perceived by the observer. The study included 55 subjects with normal vision and 15 older subjects with cataracts. All subjects were examined for visual acuity, contrast sensitivity, visual-discrimination capacity and optical quality. Subjects also completed a subjective Driving Habits Questionnaire (DHQ). Older drivers with and without visual impairment showed significantly (p < 0.05) worse visual performance and deteriorated retinal-image quality, even when their binocular visual acuity was ≥20/25. In conclusion, some visual functions are considerably diminished in older drivers, even when visual acuity is sufficient to get or renew a driver's license. Halo software enables easy quantification of night-vision disturbances such as halos, which could impede the detection of pedestrians, cyclists, or traffic signals, thereby making this system advisable in clinical practice, e.g. in the requirements for a driver's license, particularly for older drivers.

Visual impairment in stroke patients--a review

Approximately 30% of all stroke patients suffer from post-stroke visual impairment. Hemianopia is the most common symptom, but also neglect, diplopia, reduced visual acuity, ptosis, anisocoria, and nystagmus are frequent. Partial or complete recovery of visual disorders can occur, but many patients suffer permanent disability. This disability is often less evident than impairment of motor and speech functions, but is negatively correlated with rehabilitation outcome and can lead to a significant reduction in day-to-day functioning. To be visually impaired after stroke reduces quality of life and causes social isolation because of difficulties in navigating/orientating in the surroundings. A thorough diagnosis including targeted examination and later follow-up with eye examination and perimetry is essential in order to establish the extent of the visual impairment and to select the best rehabilitation strategy. Patients seem to profit from visual rehabilitation focused on coping strategies.

Antecedents of self-regulation in driving among older drivers

Maintaining quality of life and wellbeing into advanced age is a major challenge to societies. Driving is one factor contributing to an ageing individual's independence. Understanding antecedents of driving-related self-regulation is important for designing interventions to preserve safe driving in old age. This paper reports on a study that investigated factors associated with two forms of self-regulation in driving (SRD) – avoidance of difficult driving conditions and voluntary cessation of driving – in a sample of 860 Israeli drivers aged 70 and over. We examined roles of health, vision, driving experience, driving-related self-efficacy (DRSE) and global self-esteem in SRD. Health and DRSE had direct effects on SRD, and effects of vision and driving experience were mediated by DRSE. Participants who had ceased driving were older, with poorer vision and health, and less driving confidence and experience than active drivers. Statistical analyses demonstrated that SRD is affected by a reduced sense of confidence due to an initial lower level of driving experience, compounded by deteriorating vision, and that older drivers are sensitive to factors affecting their ability to drive safely. Our results demonstrate that older drivers tend to self-regulate their driving. Programmes for older adults can be introduced for diagnosing driving capabilities, improving skills and confidence, and/or helping to develop self-regulation habits of avoiding driving in difficult conditions, and assisting drivers who must adjust to driving cessation.

Elevated occupational transportation fatalities among older workers in Oregon: an empirical investigation

Older workers have an elevated risk of being killed on the job, and transportation incidents involving vehicles or mobile machinery are especially deadly for this group. The present study was designed to address the research gap in understanding contributing factors to these incidents and recommend evidence-based guidelines for interventions. We gathered and analyzed data from several sources, including the Oregon Fatality Assessment and Control Evaluation program, the Oregon Workers' Compensation system, the Census of Fatal Occupational Injuries, the Bureau of Labor Statistics, and peer reviewed research literatures. Rates and rate ratios (RR) were used to evaluate excess risk among groups. The results of this study show that older workers in Oregon have an elevated risk of fatality both in all events (RR=3.0, 95% CI 2.2-4.0) and transportation events (RR=3.6, 95% CI 2.4-5.4). Additional analyses and extant literature supports our hypotheses that multiple risk factors contribute to the phenomenon, including (a) hazard exposure, (b) organization of work, (c) physical fragility, and (d) normative cognitive, sensory, and psychomotor changes that occur with age. The evidence-based framework proposed may provide valuable guidance for developing safety interventions that protect older workers.

Alemtuzumab improves contrast sensitivity in patients with relapsing-remitting multiple sclerosis

BACKGROUND

Alemtuzumab is a monoclonal antibody directed against CD52 that depletes T and B lymphocytes.

OBJECTIVE

To evaluate the treatment effect of alemtuzumab on low-contrast vision in relapsing-remitting multiple sclerosis (RRMS) patients.

METHODS

This was a pre-defined exploratory analysis within a randomized, rater-blinded trial (CAMMS223) that was run at 49 academic medical centers in the US and in Europe. Patients with untreated, early, RRMS (McDonald, n = 334) were randomized 1:1:1 to subcutaneous interferon beta-1a (IFNB-1a), or alemtuzumab 12 mg or 24 mg. Visual contrast sensitivity was measured for each eye at baseline and quarterly, with Pelli-Robson charts.

RESULTS

The eyes of patients in the pooled alemtuzumab group (versus IFNB-1a) had a greater than 2-fold higher rate of both 3-month and 6-month sustained visual improvement, of at least 0.3 log units (2 triplets, 6 letters) (At 3 months the hazard ratio (HR) = 2.26; CI = 1.19 to 4.31; P = 0.013; and at 6 months the HR = 2.44; CI =1.16 to 5.15; P = 0.019), and they had a lower risk of 3- and 6-month sustained worsening of at least 0.15 log units (1 triplet, 3 letters) (At 3 months the HR = 0.58; CI = 0.38 to 0.89; P = 0.012; and at 6 months HR = 0.55; CI=0.35 to 0.87; P = 0.010). Over the 36-month study period, the eyes of patients in the pooled alemtuzumab group improved in mean contrast sensitivity to a greater extent than those in the IFNB-1a group (0.080 log units versus 0.038 log units; P = 0.0102).

CONCLUSIONS

Alemtuzumab was associated with a greater chance of improved contrast sensitivity in patients with RRMS and may delay the worsening of visual function. Contrast sensitivity testing was sensitive to treatment effects, even within an active comparator study design. These results support the validity of low-contrast vision testing as a clinical outcome in MS trials.

Effect of cognitive status on self-regulatory driving behavior in older adults: an assessment of naturalistic driving using in-car video recordings

Previous findings that older drivers engage in strategic self-regulatory behaviors to minimize perceived safety risks are primarily based on survey reports rather than actual behavior. This study analyzed in-car video recording of naturalistic driving of 18 patients with Alzheimer disease (AD) and 20 age-matched controls in order to (1) characterize self-regulatory behaviors engaged by older drivers and (2) assess how behaviors change with cognitive impairment. Only participants who were rated "safe" on a prior standardized road test were selected for this study. Both groups drove primarily in environments that minimized the demands on driving skill and that incurred the least risk for involvement in major crashes. Patients with AD displayed further restrictions of driving behavior beyond those of healthy elderly individuals, suggesting additional regulation on the basis of cognitive status. These data provide critical empirical support for findings from previous survey studies indicating an overall reduction in driving mobility among older drivers with cognitive impairment.