New Research on Driving Patterns in Older Adults with Glaucoma

photograph of retina showing glaucomatous cupping of the optic disc

A new study, entitled Driving patterns in older adults with glaucoma, has been published online on February 21, 2013, in BMC Ophthalmology. The study concludes that glaucoma and visual field loss from glaucoma are associated with a greater likelihood that older adults will limit driving, stop driving, or change their driving preferences.

The authors are Suzanne W. van Landingham, Chad Hochberg, Robert W. Massof, Emilie Chan, David S. Friedman and Pradeep Y. Ramulu, affiliated with the Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland.

BMC Ophthalmology is an open-access journal that publishes original peer-reviewed research in all aspects of the prevention, diagnosis, and management of eye disorders, as well as public health research and genetics.

About the Research

The authors introduce the study with the following statements:

Over 60 million people worldwide are affected by glaucoma, a number that will increase substantially as the population ages. Glaucoma prevalence is highest among the elderly, and elderly individuals with glaucoma are more likely to be visually disabled because of more advanced visual field loss and other age-related factors.

Driving is highly valued by older adults because it is often required for independence. Furthermore, driving cessation is associated with … depression and increased risk of entry into a long term care facility, even after [taking demographic and health variables into account]. Indeed, the ability to travel outside the home is consistently ranked as one of the two most important visual functions by people with glaucoma.

Drivers with glaucoma perceive greater difficulty with driving, and perceived difficulty increases with severity of visual field loss. Drivers with glaucoma have also been shown to make more driving errors during driving simulator and on-road evaluation of driving.

Some studies have also shown that visual field loss severity is associated with increased motor vehicle accidents, though others have shown that a glaucoma diagnosis is not associated with more accidents.

One explanation for why glaucoma does not consistently increase accident risk in all studied populations is that individuals with more advanced disease may limit or stop driving.

Here, we examine how driving patterns (driving limitation, driving cessation, and other driver preference) differ in glaucoma patients across a range of visual field loss severities.

More about Glaucoma and Driving Behavior

Here is additional information about the study participants, design, and results from the article abstract:

The purpose of this study is to determine if glaucoma and visual field loss from glaucoma are associated in older adults with driving cessation, limitations, and deference to another driver.

[In this cross-sectional study], 81 glaucoma subjects and 58 glaucoma suspect [control subjects] between age 60 and 80 reported if they had ceased driving, limited their driving in various ways, or preferred another to drive. (Note: A person can be considered a “glaucoma suspect” on the basis of above-normal intraocular (i.e., within the eye) pressure, an unusual appearance of the optic disc or visual field, a family history of glaucoma, or narrow angles between the iris and cornea.)

Twenty-three percent of glaucoma subjects and 6.9% of [glaucoma] suspects had ceased driving. Glaucoma subjects also had more driving limitations than [glaucoma] suspects…. Glaucoma subjects were also more likely than [glaucoma] suspects to report a greater number of driving limitations. The likelihood of reporting more limitations increased with the visual field loss severity.

(Note: A cross-sectional study involves an analysis of a population of subjects at one specific point in time, rather than studied over a more extended period of time. A prospective study, on the other hand, studies and measures a group of individuals over time and follows up with study subjects in the future.)

The Study Limitations

The authors also note the following limitations and cautions related to interpretation of the study results:

A limitation of our study was that driving changes were not assessed prospectively, so we cannot draw conclusions about the stage of disease at which driving limitations and driving cessation first occurred.

Further prospective study is merited to assess when and why people with glaucoma change their driving habits, and to determine if their observed self-regulation of driving is adequate to ensure safety.

Because of the potential for driving cessation and limitation to negatively affect individuals’ quality of life, it will be important to balance safety and independence for drivers with visual impairment due to glaucoma.

Additional Information

VisionAware will continue to provide updates for ongoing glaucoma and driving research as they become available. You can read more information on about driving concerns at Driving with Low Vision, Discussing When to Stop Driving, Claude Wood, Age 100, Talks about Giving Up Driving, Finding and Hiring a Driver, and Doctor, Can I Still Drive? A Conversation with Richard Hom, OD, MPA on the VisionAware blog.

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