Retinal injury induced by near-ultraviolet radiation in aphakic and pseudophakic monkey eyes. A preliminary report

The effect of repeated exposures to low-intensity, near-ultraviolet (UV) radiation on the retinas of phakic, aphakic, and pseudophakic monkey eyes was studied. Ten eyes (4 aphakic eyes, 3 pseudophakic eyes, and 3 normal phakic eyes) of five rhesus monkeys were used. The near-UV radiation was generated by a high-pressure mercury vapor lamp with a total radiance of 14.43 mW/cm2/sr. Exposure regimens were 5 minutes a day for 10 days, 15 minutes a day for 5 days, or 60 minutes a day for 5 days. The retinas of aphakic and pseudophakic eyes were exposed to a daily dose of more than 0.97 J/cm2, or a total dose of more than 4.9 J/cm2 in 5 days at a retinal irradiance of more than 1.0 mW/cm2. Three of four aphakic eyes and one of three pseudophakic eyes showed clinical and pathologic retinal lesions after radiation. None of the three phakic eyes was damaged. The retinal lesions showed mild opalescent thickening ophthalmoscopically and retinal pigment epithelial staining by fluorescein angiography. Histopathologically, the retinal pigment epithelium was the site of primary injury by near-UV radiation.