Retinal damage from the illumination of the operating microscope. An experimental study in pseudophakic monkeys.

An experimental study of retinal damage from the coaxial illumination of the operating microscope was performed in pseudophakic rhesus monkeys. The threshold exposure time for production of an ophthalmoscopically visible lesion was determined, and the lesions were studied with light and electron microscopy. At the "high" illumination setting, the threshold exposure was less than 7 1/2 minutes and consecutive exposures of lesser duration had an additive effect. Histologically, the lesions were identical to those which other authors have described as primarily due to the shorter wavelengths or "blue light mechanism" of damage.