Subnanosecond single laser pulse minimum-visible-lesion studies in the near infrared

Abstract

Lacking established national laser safety standards for sub-nanosecond, single pulse laser systems operating in the visible to near infrared spectral regions has resulted in research efforts designed to define the risks associated with human ocular exposure. The bulk of this work has been focused on visible wavelength laser pulses and resulting retinal threshold damage. We report threshold measurements for Minimum Visible Lesions (MVL) at the retina for picosecond (ps) laser pulses in Macaca Mulatta eyes using near infrared wavelengths (80 ps and 1064 nm). The 50% probability for damage (ED 50 ) dosages are calculated for 1 hour and 24 hour post exposures using the SAS probit analysis. The MVL ED 50 threshold and the fiducial limits at the 95% confidence level were found to be 4.16 (3.00 - 5.77) microjoules ((mu) J). Fluorescein angiography (FA) was accomplished at both 1 hour and 24 hour post exposure, however the analysis for FA is currently underway and results will not be reported here.