rss
Br J Ophthalmol 1997;81:141-144 doi:10.1136/bjo.81.2.141
  • Original Article
    • Laboratory science

Oxygen free radical damage in the cornea after excimer laser therapy

  1. Seiji Hayashi,
  2. Sei-ichi Ishimoto,
  3. Guey-Shuang Wu,
  4. Won R Wee,
  5. Narsing A Rao,
  6. Peter J McDonnell
  1. Doheny Eye Institute and the Department of Ophthalmology, University of Southern California School of Medicine, Los Angeles, USA
  1. Dr P J McDonnell, Doheny Eye Institute, 1450 San Pablo Street, Los Angeles, CA 90033, USA.
  • Accepted 14 October 1996

Abstract

AIMS/BACKGROUND To evaluate the extent of oxygen radical damage in the cornea after excimer laser ablation.

METHODS The 193 nm argon fluoride excimer laser was programmed for an average fluence of 150 mJ/cm2, with a firing rate of 5 Hz and an ablation zone diameter of 6 mm. Phototherapeutic keratectomy was performed to remove 30 μm of epithelium and 50 μm of stroma from the corneas of New Zealand white rabbits. Oxidative tissue damage after laser was determined by measuring oxidised lipids (conjugated dienes and ketodienes) in corneal lipid extracts, and by fast blue B staining to localise the lipid peroxide in the tissue.

RESULTS Conjugated diene levels were 3.73 (SD 0.56) nmol per hemicornea in ablated corneas and 1.99 (0.33) nmol per hemicornea in normal corneas (p = 0.0044). Ketodiene levels were 2.72 (0.38) nmol per hemicornea in treated corneas and 0.91 (0.12) nmol per hemicornea in normal corneas (p < 0.001). Fast blue B staining disclosed that the tissue damage occurred primarily on the surface of the ablated cornea.

CONCLUSION The presence of lipid peroxidation in the superficial corneal stroma in excimer laser treated corneas was demonstrated. This lipid peroxidation could be from oxygen free radicals generated by the infiltrating polymorphonuclear cells at the site of tissue damage.

Footnotes

    This Article

    1. Abstract
    2. Full text
    3. PDF

    Responses

    1. Submit a response
    2. No responses published

    Register for free content

    The full back archive is now available for all BMJ Journals. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006 right back to volume 1 issue 1. Register here to access the free archive of all BMJ Journals.

    Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.