E-news Exclusive

Glaucoma Vision Loss May Be a Risk Factor
for Auto Accidents

The first study to compare accident rates for drivers who have advanced glaucoma with drivers who have normal vision found that the glaucoma group had about twice as many automobile accidents.

This study, conducted in Japan using a driving simulator and presented at the annual meeting of the American Academy of Ophthalmology and the Asia-Pacific Academy of Ophthalmology, suggests that drivers should pass a visual field test to ensure adequate peripheral vision before a license is granted or renewed.

Glaucoma can partially or severely restrict a person’s peripheral vision without damaging his or her central vision or visual acuity. This means that many people who have the disease would be able to pass the visual acuity test, the only vision test now required for a driver’s license in most countries. Drivers need good peripheral vision to assess and keep up with the flow of traffic, stay in the proper lane, and detect traffic signals, pedestrians, vehicles, and other obstacles.

In this study, which was conducted at Tohoku University Graduate School of Medicine in Sendai, Japan, two groups of 36 people each were tested using a driving simulator. People in one group had advanced glaucoma, and those in the other group had normal vision. The groups were matched for age, driving experience, and other characteristics. The most common accident scenario for both the glaucoma and normal-vision groups was when a child, car, or other object suddenly entered the driver’s path from the side. The glaucoma group, however, had more than twice as many collisions as the normal-vision group.

Glaucoma affects more than 2.7 million Americans over the age of 40. It is the second leading cause of blindness worldwide. If untreated, glaucoma reduces peripheral vision and eventually causes blindness by damaging the optic nerve. This essential nerve sends signals from the retina to the brain where these signals are interpreted as the images people see. Only one-half of the people who have glaucoma are aware of it since the disease is painless and vision loss is very gradual.

As populations grow older worldwide, health officials are exploring measures that will ensure safety on the roads. For instance, in the United States visual field requirements vary from state to state, with only 12 of the 51 jurisdictions restricting licenses for those with visual impairments. Some states or territories require the installation of additional mirrors on the vehicles of these drivers.

“To help ensure everyone’s safety on our roadways, we would like to create mandatory vision testing guidelines for glaucoma patients,” says Shiho Kunimatsu-Sanuki, MD, an assistant professor in the department of ophthalmology at Tohoku University Graduate School of Medicine and the lead study researcher. “We now know that integrating the visual field test into the requirements for a driver’s license could save lives.”

With proper medical care, many people with glaucoma can maintain a level of vision that would enable safe driving. The American Academy of Ophthalmology recommends that people have a complete eye exam at the age of 40 so glaucoma and other age-related eye diseases can be diagnosed and treated early to minimize vision loss.

— Source: American Academy of Ophthalmology