Cynthia Owsley, M.S.P.H., Ph.D., and colleagues from the University of Alabama at Birmingham, conducted a study to determine the impact of cataract surgery and intraocular lens implantation on the crash risk for older adults in the years following surgery, compared with that of older adults who had cataract but elected to not have surgery.

According to background information in the article, motor vehicle crash risk in older drivers is elevated in those with cataract, a condition that impairs vision and is present in half of adults aged 65 years or older.

This study included 277 patients with cataract, aged 55 to 84 years at enrollment, who were recruited from 12 eye clinics in Alabama from October 1994 through March 1996, with four to six years of follow-up (to March 1999). There were 174 patients in the cataract surgery group and 103 in the no surgery group. During follow-up, there were 27 crashes per 4.7 person-miles of travel in the surgery group and 23 crashes per 2.6 person-miles of travel in the no surgery group.

The researchers found: "Comparing the cataract surgery group with the no surgery group, the rate ratio for crash involvement was 0.47 [53 percent lower risk of crash involvement], adjusting for race and baseline visual acuity and contrast sensitivity. The absolute rate reduction associated with cataract surgery was 4.74 crashes per million miles of travel."

"The present study suggests that cataract surgery has a previously undocumented benefit for everyday life, namely, preventing the increased crash rate that would be expected in future years without cataract removal. This information could be useful when ophthalmologists and patients discuss the benefits vs. risks of cataract surgery, and could be critical information for patients contemplating surgery who want a lifestyle that heavily depends on driving," the authors write.

"The results here suggest that it could have widespread benefit to driver safety in our society given the increase in the older driver population and the high prevalence of cataract in the population older than 65 years," the researchers conclude.

Editor's Note: This research was supported by the National Institute on Aging/National Institutes of Health, Research to Prevent Blindness, Inc., and the EyeSight Foundation of Alabama. Dr. Owsley is a Research to Prevent Blindness Senior Scientific Investigator.

Editorial: Cataract Surgery and Motor Vehicle Crashes — Proceed With Caution

In an accompanying editorial, Barbara E. K. Klein, M.D., M.P.H., of the University of Wisconsin-Madison, writes that "even assuming that a clinical trial of cataract surgery for the prevention of crashes could ethically be performed and would confirm the findings of Owsley et al, older drivers with cataracts should not necessarily be advised that cataract surgery may improve their driving performance.

"As Owsley et al are careful to note, driving performance declined for both study groups, as might be expected for an aging population of drivers. The advantage reported for drivers who had surgery for their cataract was only that their driving performance declined at a slower rate. Moreover, the relative decrease in the number of crashes in the cataract surgery group was small — only about five crashes per million miles of travel — and the potential severity of crashes averted by cataract surgery is unknown," she writes.