International Ophthalmology

, Volume 18, Issue 3, pp 159–161 | Cite as

Excimer laser photoablative filtration surgery: histology and ultrastructure in 4 human cadaver eyes

  • R. Bertagno
  • G. Giordano
  • U. Murialdo
  • F. Moreschalchi
  • G. Di Lorenzo
  • D. Venzano
  • C. E. Traverso
Articles
  • 26 Downloads

Abstract

The purpose of this study was to verify the feasibility of ab externe layer-by-layer excimer laser photoablative removal of limbal tissue down to the trabecular meshwork and to assess the damage caused by this procedure to the neighbouring structures. Excimer laser photoablation (193 nm) can remove layers of corneal tissue effectively with little or no damage to the adjacent areas. Previous experimental studies have demonstrated a decrease in outflow resistance after ab-externo photoablative removal of juxtacanalicular tissue. We have performed ab-externo photoablative removal of limbal tissue overlying the trabecular meshwork in four freshly enucleated eyes from our Eye Bank. The beam of an excimer laser (wavelength 193 nm; fluence 180 mJ/Sq.cm) was shaped using a metal mask with a rectangular opening of 1.2×2.5 mm. After removing the conjunctiva, photoablation was carried out at maximum surgical microscope magnification (40 x) until trabecular meshwork appeared at the bottom of the crater. Light microscopy showed that craters had smooth walls and their base reached the Schlemm's canal area; all structures appeared of normal morphology. Transmission electron microscopy showed a thin layer of amorphous material or pseudomembrane on the side walls of the crater; corneoscleral collagen fibers were abruptly interrupted and undistorted. At the bottom of the crater the trabecular meshwork and Schlemm's canal tissues appeared normal.

Key words

excimer laser filtration photoablation pseudomembrane 

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References

  1. 1.
    Seiler T et al. Partial external trabeculectomy with excimer laser: an experimental investigation of a new treatment for glaucoma. Laser Light Ophthalmol 1990; 3, 2: 97–109.Google Scholar
  2. 2.
    Kuwayama Y, Takagi T, Tanaka M, Takeuchi R. 193 nm excimer laser partial external trabeculectomy. Invest Ophthalmol and Vis. Sci 1992; Vol. 33: 1017.Google Scholar
  3. 3.
    Traverso CE et al. Excimer laser photoablative filtration surgery for primary open-angle glaucoma. Invest Ophthalmol and Vis. Sci 1992; Vol. 33: 1017.Google Scholar
  4. 4.
    Traverso CE, Murialdo U, Di Lorenzo G, Venzano D, De Palma G, Gandolfo E, Calabria GA, Zingirian M. Photoablative filtration surgery with the excimer laser for primary open-angle glaucoma: a pilot study. Int Ophthalmol 1992; 16: 363–5.Google Scholar
  5. 5.
    Marshall J, Trokel S, Rothery S, Krueger RR. Photoablative reprofiling of the cornea using an excimer laser: photorefraktive keratectomy. Laser Ophthalmol 1986; 1: 21–48.Google Scholar
  6. 6.
    Kerr-Muir MG et al. Ultrastructural comparison of conventional surgical and argon fluoride excimer laser keratectomy. Am J Ophthalmol 1987; 103: 448–53.Google Scholar
  7. 7.
    Sher NA, Bowers RA, Zabel RW, Frantz JM, Eiferman RA, Brown DC, Rowsey JJ, Parker P, Chen V, Lindstrom RL. Clinical use of the 193 excimer laser in the treatment of corneal sars. Arch Ophthalmol 1991; 109: 491–8.Google Scholar
  8. 8.
    Gartry D, Kerr Muir M, Marshall J. Excimer laser treatment of corneal surface pathology: a laboratory and clinical study. Arch J Ophthalmol 1991; 75: 258–69.Google Scholar

Copyright information

© Kluwer Academic Publishers 1994

Authors and Affiliations

  • R. Bertagno
    • 1
  • G. Giordano
    • 1
  • U. Murialdo
    • 1
  • F. Moreschalchi
    • 1
  • G. Di Lorenzo
    • 1
  • D. Venzano
    • 1
  • C. E. Traverso
    • 1
  1. 1.University Eye Clinic of GenovaGenovaItaly

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