[Examination of resistance of the lens capsule against the waterjet]. / Untersuchungen zur Belastung der Linsenkapsel durch den Waterjet.

BACKGROUND: Although cataract surgery is highly developed today, there are still problems such as secondary cataract. In polishing the posterior capsule lens, epithelial cells often remain, causing secondary cataracts. Additionally, there are the problems of tissue heating and endothelial cell loss during phacoemulsification by ultrasound. This could be another field for improvement of cataract surgery by using the waterjet. METHODS: After removing the cornea of freshly enucleated porcine bulbs, we used the water jet from 4 to 12 bar. The hit angel on the capsule varied between 45 degrees and 90 degrees. RESULTS: Rupture of the posterior capsule occurred at a mean of 8.5 bar using the jet at 45 degrees and a mean of 8.6 bar using the jet at 90 degrees. CONCLUSION: The waterjet pressure should not be over 4 bar during polishing of the posterior capsule.

High-speed switching of far-infrared radiation by photoionization in a semiconductor.

An investigation of subnanosecond switching of 119-microm radiation achieved by irradiating high-resistivity silicon wafers with 1.7-ns, 337-nm pulses from a nitrogen laser is presented. The experimental results are compared with a one-dimensional numerical multilayer model, which accounts for the generation, recombination, and diffusion of the free carriers and the resulting change of the far-infrared optical properties of the Si wafer.