Free running erbium:YAG laser for nonmechanical trephination in penetrating keratoplasty: First results of experimental trephination of human donor corneas

Michael Küchle, Ashley Behrens, Berthold Seitz, Achim Langenbucher, Gottfried O.H. Naumann

Research output: Contribution to journalArticle


Background: A study was carried out to evaluate the potential suitability of a free-running erbium:YAG 2.94-μm laser for trephina tion of human corneas in penetrating keratoplasty. Methods: Two human donor corneas were placed in an artificial anterior chamber and moved with an automated rotation device (one rotation per minute). An erbium:YAG laser beam (pulse duration 400 μs, repetition rate 2/s, energy density 2.5 and 15.0 J/cm2) was focused on the outer edge of a round ceramic mask placed on the human donor corneas for ablation of tissue. Results: With a fluence of 15.0 J/cm2, perforation was achieved after 500 pulses. Perpendicular central cut edges with mild stromal ridges and, by light microscopy, a 12 to 45-μm area of stromal thermal effects and focal endothelial changes up to 200 μm central to trephination were observed. Conclusions: The erbium:YAG laser could be a promising 'low-cost alternative' to the excimer laser for nonmechanical trephination in penetrating keratoplasty. Further studies will have to focus on reduction of thermal damage and on wound healing.

Original languageEnglish (US)
Pages (from-to)875-877
Number of pages3
JournalGraefe's Archive for Clinical and Experimental Ophthalmology
Issue number10
StatePublished - Oct 1 1999
Externally publishedYes


ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

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