Elevated bilirubin and visual perception in pilots.

BACKGROUND

A fatal aircraft accident of a Bo-105 helicopter on May 20, 1996 led to the suspicion that the pilot's raised serum bilirubin level could have contributed to the accident. It was suspected that an increase of bilirubin beyond 20.52 micromol x L(-1) could disturb visual perception.

METHODS

In 1998 and 1999, 101 pilots with functional hyperbilirubinemia, diagnosed as Gilbert's syndrome, were subjected to perceptual-psychological testing (signal detection test) during their periodic medical examinations at the German Air Force Institute of Aviation Medicine. The results of the psychophysiological testing were compared with a control group.

RESULTS

Reaction time and perception range increased with age and were independent of serum bilirubin level.

CONCLUSION

There is no evidence that raised serum bilirubin levels can diminish visual perceptional performance.