[The experimental study of Nd: YAG laser injuring effects on intraocular lenses made by different materials].

OBJECTIVE

To inquire the injuring effects of the Q-switched neodymium: yttrium aluminum garnet (Nd : YAG) laser on silicone, hydrogel (HEMA), acrylic, lathe cutting and cast molding polymethylmethacrylate (PMMA) intraocular lenses (IOLs).

METHODS

The Nd : YAG of different energy was focused on the posterior surface of the IOL optic portion and shot in air and BSS separately. The percentages of IOL injuries were calculated, and the morphology of the IOL injuries was observed with a scanning electron microscope.

RESULTS

Percentages of IOL injury: When the same energy of Nd : YAG laser was used, the injuring effects on the same kind of IOLs in air and in BSS were similar, while the laser energies of 0.5 mJ and 1.0 mJ were used, the injuring effects on different kinds of IOLs were significantly different, and when the energy of the laser was more than 1.5 mJ, the injuring effects were almost the same. Under different conditions, the morphology of the injury on different kinds of IOLs was different.

CONCLUSIONS

(1) The sequence of resisting ability against Nd : YAG laser injury of different kinds of IOLs from strong to weak is: The lathe cutting PMMA IOL > acrylic IOL > cast molding PMMA IOL > HEMA IOL and silicone IOL. (2) The injuring effect of high energy Nd : YAG laser on rigid IOL is more severe than that on the soft IOL. (3) The size of IOL injuries is increased with the elevation of energy level of Nd : YAG laser.