November 24, 2000 – Ottawa, Ontario – Recommended vision standards included in “Determining Medical Fitness to Drive -A Guide for Physicians” published by the Canadian Medical Association refer to possible loss of contrast sensitivity associated with laser refractive surgery. This has been incorrectly interpreted in recent months by media reports that suggest a higher risk of problems with night driving.

The expert committee of the Canadian Ophthalmological Society, which formulated the guidelines, has stated the following: “Individuals with reduced contrast sensitivity may experience difficulty with driving, in spite of having adequate visual acuity to drive. However, it is unclear at this time what level of reduction in contrast sensitivity represents an unacceptable risk for driving. Loss of contrast sensitivity can be associated with increased age, cataracts, refractive surgery as well as other ocular disorders. Individuals should be made aware of any significant reduction in contrast sensitivity.”

According to Dr. Duncan Anderson, Chairman of the Committee and Chairman, Department of Ophthalmology, St.Paul’s Hospital, Vancouver, BC, media reports have focused on the statement, “Individuals with reduced contrast sensitivity may experience difficulty with driving” while ignoring the qualification that, “It is unclear at this time what level of reduction of contrast sensitivity represents an unacceptable risk for driving.”

Dr. Anderson further explains, “the committee on vision standards and driving did not list contrast sensitivity as a contraindication. In fact, current scientific evidence does not support any contraindication to driving related to refractive surgery.”

Dr. Bruce Jackson, Director General, University of Ottawa Eye Institute, explained that patient screening prior to a laser procedure is essential to ensure positive outcomes that definitively improve vision and leave patients satisfied. “There are patients who are not optimal candidates for laser surgery, but these patients are a small minority,” said Dr Jackson. “Some patients have a high degree of myopia or hyperopia, eye abnormality or unusually large pupils- pupils that extend beyond the preferred diameter for surgery. These patients may experience some loss of contrast acuity at night. On the other hand, some make an informed decision to proceed with the surgery, believing that being freed from the need for eyeglasses outweighs a slight reduction in night vision.”

Both the Canadian Ophthalmological Society (COS) and the Canadian Society of Cataract and Refractive Surgery (CSCRS) feel that careful patient selection is the key to good outcomes following refractive surgery.

For more information:
Hubert Drouin, Executive Director,
1-800-267-5763 or (613) 729-6779 ext 225;
e-mail: hdrouin@eyesite.ca