Comparison of the Maximum Permissible Exposure with the Doses Required to Induce Retinal Alternations from Q-switched Ruby Laser Exposures.

摘要

Documents which state maximum permissible exposures (MPE) for laser radiation have been criticized by the military system developers and the laser industry as being too conservative. In this report, the MPEs were compared with the doses required for three exposure conditions where dose-response relationships for the ocular exposure of rhesus monkeys to a Q-switched laser have been previously reported. The exposure conditions were: (1) the production of an ophthalmoscopically visible lesions for a minimal retinal irradiance diameter (50 microns), (2) the production of an ophthalmoscopically visible lesion for a 1000 micron retinal irradiance diameter, and (3) the production of prolonged electron microscopic changes in the outer segments of the photoreceptors for a 1000 micron retinal irradiance diameter. The dose considered in condition 3 was 10 times below that required for condition 2. By using the intrabeam viewing standard, the dose required for the production of an ophthalmoscopically visible lesion in the macula for a minimal retinal irradiance diameter was only 50 times greater than the MPE. The doses for the large retinal irradiance conditions of 2 and 3 were compared to the extended source viewing standard by calculating the dose received from an extended source that is irradiated at the MPE and imaged to 1000 microns on the retina.