Histopathologic study of laser photocoagulation in rabbit retina

To compare histological alterations of retinal spots produced by argon laser,frequency doubled laser and semiconduct laser. Retinal photocoagulation by semiconduct laser,frequency doubled laser and argon laser were performed on 72 pigmental rabbits.According to different times, retinal and choroid alterations were observed and compared using optical microscopy and transmission electronic microscope. Three kinds of lasers can lead to the same histological alterations with different energy. In early stage, the alteration of choroid produced by semiconduct laser was more serious than that by the other two lasers, With observation for a longer time (three months), changes of the choroid could recover completely, and there was no obvious histopatholigic difference from the other two lasers. For longer observation, there is no obvious difference in the inner retina and choroid among the three kinds of lasers when the leision is limited to the outer retina (defect of outer nuclear layer) clinically.