Binocular visual field loss increases the risk of getting into a car accident, and approximately 23%of subjects in this study were involved in more than one incident. Photo: Miquel Perello Nieto. Click image to enlarge.

It’s self-evident that binocular visual field loss can greatly affect personal activities in patients’ daily lives, including driving. However, not much is known about how the severity and location of visual field loss affects their ability to drive. In a recent large population-based study, researchers from Australia matched data from visual field tests to corresponding government documentation on crashes to uncover more about the relationship between the two.

For their study, the researchers used two databases to identify any possible correlations between field loss and car crash incidents. They analyzed tests and documents from 1990 to 2019, specifically of patients over the age of 50. Since this study attempts to show that extent and location of visual field loss alters the risk of car crashes, the researchers classified severity levels into three categories (mild, moderate and severe) and the locations of the eye into five sections (upper left, upper right, lower left, and lower right quadrants and central). A total of 31,296 patients with binocular visual field loss were identified for this study.

“Overall, 38% of the cohort of 31,296 older adults aged 50+ had binocular visual field loss; however, of those involved in an incident crash, over 55% had binocular visual field loss,” said the researchers in their paper published in Ophthalmic Epidemiology. A total of 13.8 % of the study’s population were involved in vehicle crashes. The researchers reported that visual field loss, regardless of location, significantly increased the odds of crashing by 84%, regardless of severity and location.

However, for patients with severe levels of visual impairment, their risk for crashing was further increased. Depending on the location of the deficit, the odds differed. The risk increased by 98% in the upper left quadrant, 97% in the lower left quadrant, 89% in the lower right quadrant and 95% in the upper right quadrant. Severe visual field loss in the central region did not significantly increase the chance of a vehicle incident.

“Our findings highlight the importance of education regarding safe driving that is based on the individual’s specific pattern of visual field loss,” stated the researchers in their paper “This information will be extremely helpful for clinical practice management to ensure the safety of older adults as they continue to drive in Australia and worldwide.”