Retinal Changes in White Rabbits after Exposure to the Light of an Operating Microscope

ABSTRACT

PURPOSE: This study was performed to investigate the potential damage to white rabbit retinas caused by an operating microscope light. METHODS: A total of 18 white rabbits were exposed to the light of an operating microscope for 60 minutes. Fundus examination, fluorescein angiography (FAG), and electroretinogram (ERG) were performed before exposure and 1 hr, 1 day, 7 days and 14 days afterward to allow for serial comparisons. Light and electron microscopic examinations were performed to evaluate the changes in the rabbit retinas over time. RESULTS: Signs of retinal damage upon fundus examination and FAG were not found before or after exposure to the light of an operating microscopy. ERG, however, showed significant reduction in the dark-adapted rod response 1 hour after light exposure, and significant decline in the amplitude of the maximal combined response a- and b-wave 1 day after light exposure in the rabbit retinas. ERG findings returned to the pre-exposure level after 2 weeks. Ultrastructural injury to the photoreceptor outer segments and the retinal pigmented epithelium, observed using transmission electron microscopy, recovered to the pre-exposure state after 2 weeks. CONCLUSIONS: The risk of retinal damage should be considered as an early result of exposure to the light of an operating microscope, even in normal retinal findings.