[Effects of laser fragmentation of the lens mass on ocular tissues in experimental animals]

Side effects of laser on the posterior corneal epithelium and the retina during intracapsular YAG laser fragmentation of transparent lens fibers in various modes of laser operation were experimentally studied. The pulse power varied from 3 to 7.7 mJ, number of pulses from 55 to 160, length of exposure 10(-8) sec, diameter of the spot in the focus 30 microns. Animal eyes were enucleated on days 3-6 after the procedure. Posterior corneal epithelium was examined in the Hitachi scanning electron microscope, the retina in a light microscope. The findings evidence that injury to the posterior corneal epithelium in intracapsular YAG laser fragmentation of the lens depends mostly on the number of pulses and not on the exposure energy. A safe number of coagulates should not surpass 100, this being quite sufficient for fragmentation of the lens fibers at exposure power of 5-6 mJ. Such operation mode is safe for the retina as well, this recommending it for clinical use.