The ex vivo pig eye as a replacement model for laser safety testing.

The purpose of this study was to evaluate the viability of ex vivo pig eyes as a replacement model for in vivo testing in the establishment of laser eye safety standards. Previous studies of pulsed energy absorption at 3.8 microm were performed using rhesus monkey cornea at pulse durations two orders of magnitude shorter than the 8-micros pulses used in the current study. Ex vivo pig eyes were exposed to laser pulses of various energies and then evaluated to establish the statistical threshold for corneal damage. Tissue analysis (histologic evaluation) was used to determine the extent of damage to the cornea. These results can be used in the establishment of safety standards for laser use; our findings also suggest that ex vivo pig eyes are suitable models for this purpose.