Flicker electroretinograms and visual evoked potentials in the evaluation of laser flash effects

Electroretinograms (ERG's) and visual evoked potentials (VEP's) were recorded from four cynomolgus monkeys in response to a sinusoidally flickering argon laser beam (514 nm) producing a 50-micron spot on the fovea. Super-position of a 20-Hz train of six pulses of Q-switched (120 ns) frequency-doubled neodymium laser light (532 nm) at "safe" exposure energies in 250 ms had no significant effects on the ERG (p greater than 0.05). The VEP was disrupted significantly (p less than 0.001) but demonstrated recovery within 500 ms of the initial pulse. Therefore, flash effects of pulsed visible lasers at these doses on suprathreshold luminance processing are probably limited only to the exposure period.