Focal laser photophacoablation of normal and cataractous lenses in rabbits: preliminary report.

We evaluated the effect of focal laser photophacoablation on (1) a normal lens and (2) previously induced traumatic anterior cortical and posterior subcapsular cataracts in New Zealand albino rabbits. A Q-switched neodymium:YAG (Nd:YAG) laser was used to deliver 6 to 97 50 microns laser spots of 2.0 mJ to 8.3 mJ of energy/pulse to the normal lens. A neodymium:YLF (Nd:YLF) laser was used to deliver 60 microJ to 140 microJ of energy/pulse with a 0.3 mm to 0.6 mm cube at 1053 nm to ablate selective parts of the normal and cataractous lens. The Nd:YAG laser photoablation of the normal lens produced persistent circular opacities lasting up to one year. The Nd:YLF laser photoablation of the normal lens produced an empty space in the area of treatment (visualized as increased 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 evidence of surrounding lenticular damage. Focal Nd:YLF laser photoablation of lenticular opacities appears to be a relatively safe and noninvasive 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.