Graefe's Archive for Clinical and Experimental Ophthalmology

, Volume 238, Issue 1, pp 33–39

Application of ultrashort laser pulses for intrastromal refractive surgery

Authors

  • H. Lubatschowski
    • Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hanover, Germany e-mail: hl@lzh.de Tel.: +49-511-2788279 Fax: +49-511-2788100
  • G. Maatz
    • Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hanover, Germany e-mail: hl@lzh.de Tel.: +49-511-2788279 Fax: +49-511-2788100
  • A. Heisterkamp
    • Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hanover, Germany e-mail: hl@lzh.de Tel.: +49-511-2788279 Fax: +49-511-2788100
  • U. Hetzel
    • Institut für Pathologie, Tierärztliche Hochschule Hannover, Hanover, Germany
  • W. Drommer
    • Institut für Pathologie, Tierärztliche Hochschule Hannover, Hanover, Germany
  • H. Welling
    • Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hanover, Germany e-mail: hl@lzh.de Tel.: +49-511-2788279 Fax: +49-511-2788100
  • W. Ertmer
    • Institut für Quantenoptik, Universität Hannover, Hannover, Germany
CLINICAL INVESTIGATION

DOI: 10.1007/s004170050006

Cite this article as:
Lubatschowski, H., Maatz, G., Heisterkamp, A. et al. Graefe's Arch Clin Exp Ophthalmol (2000) 238: 33. doi:10.1007/s004170050006

Abstract 

· Background: Recently, laser systems have become available which generate ultrashort laser pulses with a duration of 100–200 femtoseconds (fs). By generating micro-plasmas inside the corneal stroma with fs pulses, it is possible to achieve a cutting effect inside the tissue while leaving the anterior layers intact. The energy threshold to generate a micro-plasma with fs pulses is some orders of magnitude lower than it is for picosecond or nanosecond pulses. This results in a strong reduction of the thermal and mechanical damage of the surrounding tissue.· Methods: With a titanium:sapphire fs laser system, the cutting effect on corneal tissue from freshly enucleated porcine eye globes was investigated with different pulse energies. The irradiated samples were examined by light and electron microscopy. The laser-induced pressure transients and the laser-induced bubble formation were analysed with a broadband acoustic transducer and by flash photography. · Results: With fs laser pulses, the extent of thermal and mechanical damage of the adjacent tissue is in the order of 1 µm or below and therefore comparable with the tissue alterations after ArF excimer laser ablation. Using pulse energies of approximately 1–2 µJ and a spot diameter of 5–10 µm, intrastromal cuts can be performed very precisely in order to prepare corneal flaps and lenticules.· Conclusion: Femtosecond photodisruption has the potential to become an attractive tool for intrastromal refractive surgery.

Copyright information

© Springer-Verlag Berlin Heidelberg 2000