Visible lesion laser thresholds in Cynomolgus (Macaca fascicularis) retina with a 1064 nm 12-ns pulsed laser

Abstract

A series of experiments in a new animal model for retinal damage, cynomolgus monkeys (Macaca fascicularis), have been conducted to determine the damage threshold for 12.5-nanosecond laser exposures at 1064 nm. These results provide a direct comparison to threshold values obtained in rhesus monkey (Macaca mulatta), which is the model historically used in establishing retinal maximum permissible exposure (MPE) limits. In this study, the irradiance level of a collimated Gaussian laser beam of 2.5 mm diameter at the cornea was randomly varied to produce a rectangular grid of exposures on the retina. Exposures sites were fundoscopically evaluated at post-irradiance intervals of 1 hour and 24 hours. Probit analysis was performed on dose-response data to obtain probability of response curves. The 50% probability of damage (ED50) values for 1 and 24 hours post-exposure are 28.5(22.7-38.4) LJ and 17.0(12.9-21.8) PU, respectively. These values compare favorably to data obtained with the rhesus model, 28.7(22.3-39.3) lJ and 19.1(13.6-24.4) pJ, suggesting that the cynomolgus monkey may be a suitable replacement for rhesus monkey in photoacoustic minimum visible lesion threshold studies.

Segmentation of laser induced retinal lesions using deep learning (December 2021)

“…In generating this data to support the standards, AFRL maintains a vast collection of imagery containing laser damage induced by a broad range of sources. [30][31][32] This study has provided a significant basis for our understanding of laser bioeffects. All retinal fundus images were acquired from Macaca fascicularis or Macaca mulatta subjects.…”

“…The data generated has been incorporated into national and international safety standards such as the International Electrotechnical Commission 60825, and the ANSI Z 136 standards. In generating this data to support the standards, AFRL maintains a vast collection of imagery containing laser damage induced by a broad range of sources 30–32 . This study has provided a significant basis for our understanding of laser bioeffects.…”