Ocular hazards of the Q-switched erbium laser.

The threshold for ocular damage was determined in owl monkeys with the use of a Q-switched erbium-glass laser at 1.54/J. constructed in the laboratory. Ocular damage was limited to the cornea and characterized by localized opacification of the epithelium and stroma. All exposures to energy densities greater than 30 j./cm. produced injury. The median level for damage occurred at 21 j./cm., and no injury could be detected below 17 j./cm.. Comparison with threshold values for ocular damage by Q-switched lasers operating in the visible and near visible portion of the spectrum shows that the erbium laser offers promise as a relatively "safe laser."