Thermoacoustic wave generation and propagation in the cornea - The potential for damage

Alvin K. Benson, C. Brent Bargeron, Samuel L. Brady, Adam W. Denning, Leland M. Page, Russell L. McCally

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Carbon dioxide lasers are used in numerous applications that involve human exposure to the radiation that can produce ocular injury. The objective of this study is to show that the thermal gradient produced in the eye by the radiation from an 80 ns CO2 laser pulse can generate a thermoacoustical tensile pressure wave with large enough magnitude to rupture the epithelial layer of the cornea. A Gaussian-shaped temperature distribution will be employed. It is assumed that the corneal tissue is inhomogeneous, with the density and wave velocity varying slowly in space. Under these conditions, the acoustical wave equation is decoupled into two first-order partial differential equations, one that propagates energy into the eye from the point of thermoacoustical wave generation, and the other toward the front of the eye. These equations are solved numerically using the Lax-Wendroff numerical method. A compressional wave generated in the epithelial tissue of the cornea due to the thermal gradient of the laser arrives at the air-tear layer interface with a pressure amplitude of-6600 Pa. When this wave is reflected back into the eye, the resulting tensile pressure wave has a tensile strength of approximately 4.6 × 10 8 Pa/m just inside of the epithelial layer of the cornea. This is an order of magnitude larger than what is necessary to produce cellular damage to the cornea.

Original languageEnglish (US)
Title of host publicationOphthalmic Technologies XVII
DOIs
StatePublished - Aug 31 2007
EventOphthalmic Technologies XVII - San Jose, CA, United States
Duration: Jan 20 2007Jan 23 2007

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume6426
ISSN (Print)1605-7422

Other

OtherOphthalmic Technologies XVII
CountryUnited States
CitySan Jose, CA
Period1/20/071/23/07

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging

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  • Cite this

    Benson, A. K., Brent Bargeron, C., Brady, S. L., Denning, A. W., Page, L. M., & McCally, R. L. (2007). Thermoacoustic wave generation and propagation in the cornea - The potential for damage. In Ophthalmic Technologies XVII [642628] (Progress in Biomedical Optics and Imaging - Proceedings of SPIE; Vol. 6426). https://doi.org/10.1117/12.712253