Product Code: ILSC2009_201

On the Time Dependence of the Laser-induced Retinal Injury Thresholds in the Nanosecond to Millisecond Time Domain
Authors:
David Lund, US Army Medical Research Detachment; San Antonio TX USA
Presented at ILSC 2009

The wavelength dependence of the MPE for retinal exposure to durations greater than
1 nanoseconds have essentially unchanged since the 1970s (ANSI, ICNIRP, IEC). When guidance was included in 2000 for exposure durations less than 1 ns, the new MPE was set equal to the existing MPE at 1 nanoseconds. Recent studies have measured laser-induced retinal injury thresholds only a factor of 3 higher than the MPE for point-source exposure in NHP eyes for 3-5 ns duration exposures at 532 nm and, in fact if the incident beam has a divergence of 5 mrad, the resulting injury threshold is almost equal to the MPE. This paper will examine the existing in vivo and in vitro laser-induced retinal injury database for nanosecond to millisecond exposure durations to determine if a change in the guidelines should be considered.