97th DOG Annual Meeting 1999



W. Wetzel

Due to the high absorption of its radiation at the tissue water, the Erbium:YAG laser (2940nm wavelength) is a favorable energy source for photoablation of several tissues. Former in-vitro studies have shown the ability to remove human lens material with only minimal thermal side effects.

Materials and methods: We used an Er:YAG laser device designed for clinical application (Phacolase, Aesculap-Meditec, Germany). The laser pulse energy could be varied between 5 and 50mJ, the repetition rate between 10 and 100Hz. The energy was guided via a special coated ZrF fiber to handpieces of different design, all containing a low-OH quartz fiber. 25 lenses of patient eyes with various cataract densities were treated.

Results: The best efficacy of lens fragmentation could be achieved using lower pulse energies and higher repetition rates. Total laser energies varied between 15 and 250J. Problems occurred in treatment of very hard lens nuclei. The design of the application system markedly influenced time efficiency of the procedure.

Conclusions: The Er:YAG laser is a feasible device to minimize thermal energy required for lens removal. Now, applications system and operation strategy have to be further improved for better efficiency.

Eye Surgery Center Weinheim, Bismarckstr. 4, D-69469 Weinheim