Permanent blindness from laser exposures in laboratory and industrial accidents

摘要

Abstract: Legal entanglements prevent publication of details on most laboratory and industrial laser accidents in the USA. Many macular injuries involving the fovea show no signs of recovery after several years. Both single eye (usually the dominant one) and binocular exposures are found usually resulting in large deficits in visual performance. The primary lesion is rarely, if ever, centered in the fovea, but is eccentric, superior and nasal and in the parafoveal zone. Accidental laser exposures below the damage threshold are sometimes falsely implicated causally in pre-existing retinal pathology, the grandmother syndrome. Another source of confusion is malingering, either hysterical or purposeful. One test for macular function has been designed to detect malingering, the flash Amsler grid. Functional loss has not been seen without retinal pathology that is easily visible with an ophthalmoscope. The circumstances of almost all accidents resulting in permanent damage are similar and involve Q-switched Nd:YAG lasers at 1,064 nm with the exposure individual staring directly at something in the beam path on purpose. The injurious exposure to the beam occurs by reflection or through an improperly used attenuator. Almost all were foreseeable by well established hazard analysis techniques and preventable by standard laser safety programs or conventional engineering controls.!5