PURPOSE: A new mechanism for ablating corneal tissue is proposed, based on photospallation with short pulse mid-infrared (IR) laser radiation. METHODS: By using a judicious combination of high absorption, short pulses, and low fluences, ablation with this process can potentially remove tissue in a highly localized manner with submicron collateral thermal damage characteristics similar to those achieved by excimer lasers. We provide a brief qualitative overview of aspects of the spallation process that distinguish it from the more familiar photoablation and photothermal mechanisms. RESULTS: Results of preliminary parametric analysis based on one-dimensional models of thermoelastic expansion are summarized. CONCLUSION: These preliminary calculations lend support to the conjecture that corneal tissue can be removed effectively with strongly absorbed nanosecond pulses from a mid-IR laser, using operational fluence levels of less than 200 mJ/cm2.
PURPOSE: A new mechanism for ablating corneal tissue is proposed, based on photospallation with short pulse mid-infrared (IR) laser radiation. METHODS: By using a judicious combination of high absorption, short pulses, and low fluences, ablation with this process can potentially remove tissue in a highly localized manner with submicron collateral thermal damage characteristics similar to those achieved by excimer lasers. We provide a brief qualitative overview of aspects of the spallation process that distinguish it from the more familiar photoablation and photothermal mechanisms. RESULTS: Results of preliminary parametric analysis based on one-dimensional models of thermoelastic expansion are summarized. CONCLUSION: These preliminary calculations lend support to the conjecture that corneal tissue can be removed effectively with strongly absorbed nanosecond pulses from a mid-IR laser, using operational fluence levels of less than 200 mJ/cm2.