Near ultraviolet radiation elicits visual evoked potentials in children

Objective: Ultraviolet radiation can be transmitted through the ocular medi a, as well as stimulate the retina, in some invertebrate, vertebrate and ma mmalian species. This study sought to determine if near ultraviolet radiati on (W-A) can elicit visual evoked potentials (VEPs) in young humans. Methods: VEP responses to 10 nm half-peak bandwidths of 340, 360 and 500 nm stimuli were measured in 8 children aged 7-10 years. Each VEP was based on an averaged response to 200 flashes and was recorded using a sensitivity o f 250 mu V (full scale) with the International 10-20 electrode placements F -z, O-1, O-z, O-2, and A(1). Peak latencies (ms) were measured for the seco nd negative peak, N-2, third positive peak, P-3. and third negative peak, N -3. The amplitude (mu V) between N-2 and P-3 was also measured. Results: Each child demonstrated a VEP response to both visible and UV-A st imuli. Most VEP parameters relative to the 340 and 360 nm stimuli (P < 0.05 to P < 0.001) were significantly different from the VEP responses to the 5 00 nm stimulus. Conclusion: The results indicate that the near ultraviolet stimuli were ind eed visible to the young human eye. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.