[Retinal damage induced by visible blue and near-infrared light of an operating microscope]

The authors evaluated possible hazards to the retina caused by the longer wavelength component in the illumination system of the surgical microscope. Thirty six pigmented and eleven albino rabbit eyes were exposed to blue or near-infrared light for 60 minutes. Ophthalmoscopically visible light damage to the retina developed in 4 of 5 pigmented rabbit eyes after illumination at a power setting of 8 mW/cm2 for blue and 50 mW/cm2 for near-infrared light. These power settings were equivalent to those used in clinical tests. The light damage developed immediately after illumination with near-infrared light and a few days after illumination with blue light. No light damage developed in albino rabbits with near-infrared light at current power setting. The findings suggest the possibility that clinical retinal damage may develop in human eyes when exposed to near-infrared light from surgical microscopes.