TY - JOUR

T1 - Application of ultrashort laser pulses for intrastromal refractive surgery

AU - Lubatschowski, Holger

AU - Maatz, Gero

AU - Heisterkamp, Alexander

AU - Hetzel, Udo

AU - Drommer, Wolfgang

AU - Welling, Herbert

AU - Ertmer, Wolfgang

PY - 2000/1

Y1 - 2000/1

N2 - Background: Recently, laser systems have become available which generate ultrashort laser pulses with a duration of 100-200 femto-seconds (fs). By generating microplasmas 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.

AB - Background: Recently, laser systems have become available which generate ultrashort laser pulses with a duration of 100-200 femto-seconds (fs). By generating microplasmas 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.

UR - http://www.scopus.com/inward/record.url?scp=0034020558&partnerID=8YFLogxK

U2 - 10.1007/s004170050006

DO - 10.1007/s004170050006

M3 - Article

C2 - 10664050

AN - SCOPUS:0034020558

VL - 238

SP - 33

EP - 39

JO - Graefe's Archive for Clinical and Experimental Ophthalmology

JF - Graefe's Archive for Clinical and Experimental Ophthalmology

SN - 0721-832X

IS - 1

ER -