Purchase this article with an account.
Carrie E Huisingh, Gerald McGwin, Joanne M Wood, Cynthia Owsley; Driving visual fields and retrospective at-fault motor vehicle collision involvement in older drivers: a population-based study. Invest. Ophthalmol. Vis. Sci. 2014;55(13):2681.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Driving a vehicle occurs in a complex and ever-changing roadway environment. Previous studies suggest that visual field impairment compromises certain aspects of driving performance and increases the risk of MVC involvement, particularly for older adults. However, the degree or spatial extent of field loss that elevates crash risk is not clear. The purpose of this study was to examine the association between visual field impairment and recent history of at-fault MVC involvement among older drivers.
Characteristics were assessed in a population-based sample of 2000 licensed drivers aged 70 and older from north central Alabama. The spatial extent of the visual field was assessed for each eye separately using a 20-point custom test designed for the Humphrey Field Analyzer Model II-i. The test points are in the visual field area when a driver looks through a vehicle’s windshield. Monocular visual fields were combined to form a binocular field based on the more sensitive point from the two eyes. Impairment was defined as a threshold in the lower (worse) quartile for the overall visual field, region-specific quartiles, and point-specific quartiles. Information on at-fault MVC involvement within five years prior to enrollment was obtained from the Alabama Department of Public Safety. Poisson regression models were used to calculate the crude and adjusted rate ratios of MVC involvement among older drivers in the lowest quartile of sensitivity versus those in the upper quartiles.
Subjects with a threshold in the lower quartile of the overall visual field had a 1.88 (95% CI=1.37-2.57) increased rate of at-fault MVC involvement. This pattern was relatively consistent across all regions and individual points. The association increased as the number of impaired regions and the number of impaired points increased. After adjusting for age, gender, race, visual acuity, contrast sensitivity, and MMSE score, an association of visual field impairment in the overall visual field persisted (adjusted RR 1.42, 95% CI=1.09-1.84).
Older drivers with visual field impairment have an increased rate of at-fault MVC compared to those with less impaired or normal visual fields. The visual field test targeting the visual field area utilized when gazing through the windshield of a vehicle can be used to identify older drivers at increased risk for an at-fault MVC.
This PDF is available to Subscribers Only