Ocular parameters are influenced by sleep derivation and the use of chemical substances which are two major causes for traffic accidents. We assessed the use of these parameters as an objective screening tool for a driver's fitness for duty. Pupillary diameter, pupil reaction to light and saccadic velocity were measured in 29 army truck drivers every morning for two months and compared to baseline measurements taken while the subjects werealert. An index which expressed the difference between study and baselinemeasurements was calculated, and drivers with significant deviation from baseline were disqualified and interviewed. Non-disqualified drivers served as controls. Twenty-nine percent of disqualified drivers reported sleeping less than the minimum of 7 h required by army regulations compared with8% of control drivers (p = 0.01). Disqualified drivers had worse sleep quality the night before the test (Groningen Sleep Quality Scale, p = 0.03) and incurred more accidents per driving day during their service (0.023 vs. 0.015 accidents/day, p = 0.03). Two disqualified drivers admitted to using alcohol or sleeping pills. Thus, these ocular parameters may serve as ascreening tool for drivers that are at high risk for driving. Drivers whowere disqualified even once, tend to be involved in more motor vehicle accidents than their peers. (A) Reprinted with permission from Elsevier.
Abstract