FOCAL LASER PHOTOPHACOABLATION OF NORMAL AND CATARACTOUS LENSES IN RABBITS - PRELIMINARY-REPORT

We evaluated the effect of focal laser photophacoablation on (1) a nor mal lens and (2) previously induced traumatic anterior cortical and po sterior subcapsular cataracts in New Zealand albino rabbits. A Q-switc hed neodymium:YAG (Nd:YAG) laser was used to deliver 6 to 97 50 mu m l aser spots of 2.0 mJ to 8.3 mJ of energy/pulse to the normal lens. A n eodymium:YLF (Nd:YLF) laser was used to deliver 60 mu J to 140 mu J of energy/pulse with a 0.3 mm to 0.6 mm cube at 1053 nm to ablate select ive parts of the normal and cataractous lens. The Nd:YAG laser photoab lation of the normal lens produced persistent circular opacities lasti ng up to one year. The Nd:YLF laser photoablation of the normal lens p roduced an empty space in the area of treatment (visualized as increas ed translucency), followed by a return to normal lens architecture at two days. The area remained translucent by slitlamp biomicroscopy for up to six months. Partial photoablation of the induced cataracts with an Nd:YLF laser produced partial clearing of the opacity without any e vidence of surrounding lenticular damage, Focal Nd:YLF laser photoabla tion of lenticular opacities appears to be a relatively safe and nonin vasive procedure that can be used for focal lens ablation without lens capsule disruption. The potential use of this treatment for selective removal of focal lens opacities requires further study.