Abstract
Purpose :
To explore the driving difficulties of older adults with age-related macular degeneration (AMD) using a detailed assessment of on-road driving performance.
Methods :
33 participants aged 65 years and older with a diagnosis of AMD (M = 76.6 ± 6.1 years; AREDS grades in the better eye: early (61%) and intermediate (39%)) and 73 visually normal controls (M = 74.7 ± 5.0 years) have been tested in this ongoing study. All participants were current drivers. Participants completed a battery of vision and cognitive function tests. On-road driving performance was assessed in a dual-brake vehicle along a 19.4 km route. Overall driving safety was rated on a 10-point scale (higher values represent better performance) by an experienced occupational therapist who was masked to the visual status of the drivers. Performance was rated with respect to seven driving behaviors at 149 locations along the route (categorized into six traffic situations); the number of critical errors (CE) involving an instructor intervention was also recorded.
Results :
Drivers with AMD were rated as less safe than controls (4.8 vs 6.0; p=0.025) and driving safety was associated with AMD severity (early: 5.5 vs intermediate: 3.7), even after adjusting for age and other potential covariates. Drivers with AMD had a higher CE rate than controls (RR 3.4, 95% CI 1.8 - 6.2, p<0.001). The likelihood of a CE involving an observation error was 2.8 times greater (95% CI 1.2 - 6.6, p=0.024) in the drivers with AMD. Furthermore, drivers with AMD exhibited more driving behavior errors involving observation and at traffic light controlled intersections (p<0.037).
Conclusions :
Some drivers with AMD exhibit impairments in their driving ability, particularly during complex driving situations and involve problems with observation. These findings have important implications for the training and remediation of older drivers with visual impairment.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.