Femtosecond laser-induced cavitations in the lens of the human eye

Line Kessel, Jose Nymand, Michael Harbst, Mike van der Poel, Lars Eskildsen, Michael Larsen

    Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review


    Ultrafast femtosecond lasers are used increasingly for a wide range of medicai purposes. The immediate tissue response to pulses above a certain threshold is optically or laser induced breakdown, which is often visible as gas-filled cavities that persist for some time. In the present study, we attempted to define the cavitation threshold in the human lens in vitro using multiphoton effects base d on radiation from a femtosecond 800 nm Ti:Sapphire laser. Cavitations were observed from pulse energy densities exceeding 16 mJ/cm2, but only after several minutes of exposure and not as a result of a single laser pulse. This suggests that cavitations were caused by a process which differs ITom the single-pulse cavitations observed at higher intensities. To evaluate whether the release of gas was caused by ionization and plasma formation or by thermal effects, we introduced pauses into the pulse train, which did not change the total exposure time needed to form a cavitation. This suggests that local heating did not play a significant role in producing the observed phenomenon, suggesting that photochemical reactions may be involved. These results demonstrate that there are several types of ultrafast laser effects in the len s that have a potential for therapeutic application and treatment of eye dis ease though further studies are needed to shed light on the nature of the formation of delayed cavitations.
    Original languageEnglish
    Publication date2007
    Publication statusPublished - 2007
    EventEuropean Conferences on Biomedical Optics: Therapeutic Laser Applications and Laser-Tissue Interactions - Munich, Germany
    Duration: 17 Jun 200721 Jun 2007


    ConferenceEuropean Conferences on Biomedical Optics


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