Retinal function in Swedish ophthalmologists using argon lasers as reflected in colour contrast sensitivity. Normal thresholds in the great majority of the cases.

PURPOSE To map the colour contrast sensitivity (CCS) and possible elevations of colour contrast thresholds in Swedish ophthalmologists operating argon lasers. MATERIAL AND METHODS CCS was measured by a computer and colour monitor system developed by Arden and co-workers. CCS of 58 Swedish ophthalmologists, all users of argon laser, was compared to 26 age-matched controls. The ophthalmologists provided information on their professional use of lasers, whether the laser was equipped with a blue-absorbing filter, and the length of time spent in retinal surgery. RESULTS There was no significant difference in colour vision comparing laser-users to controls (p>0.2). However, eight subjects showed elevated tritan thresholds (>1 SD above mean), in three of the cases an elevation >2 SD above mean. All these colleagues had an extensive exposure to blue-green laser and/ or a long time spent operating. Compared to others, they had performed more laser sessions prior to the lasers being equipped with protecting filters (p<0.01). CONCLUSION Normal thresholds were found in a majority of the cases and no permanent impairment of retinal function was observed among these ophthalmologists. However, the laser-users with the greatest number of sessions seemed to show a certain decrease in retinal function as reflected in tritan thresholds.