Absence of scar formation in human donor cornea with prior laser in situ keratomileusis.

Abstract

PURPOSE:

To investigate transglutaminases (enzymes capable of cross-linking extracellular matrix proteins to proteolysis-resistant complexes during scar tissue formation) in a human donor cornea after successful laser in situ keratomileusis (LASIK) without clinical complications and to compare with the results in a human donor cornea with corneal scarring after corneal injury.

SETTING:

Department of Ophthalmology, Ludwig-Maximilians University, Munich, Germany.

METHODS:

A donor cornea with prior uneventful LASIK treatment and 1 with corneal scarring after penetrating injury were investigated. Cryostat sections were stained immunohistochemically for tissue transglutaminase (tTG), keratocyte transglutaminase (kTG), and their reaction product epsilon-(gamma-glutamyl)-lysine.

RESULTS:

With light microscopy, the flap interface of the LASIK-treated eye could hardly be detected, while in the injured eye, infiltration of cells and a clear margin next to the scar formation were present. Immunohistochemistry demonstrated a distinct staining for tTG, kTG, and epsilon-(gamma-glutamyl)-lysine in the corneal scar. In contrast, neither transglutaminase nor epsilon-(gamma-glutamyl)-lysine staining could be observed at the flap margin or in the interface of the LASIK-treated donor eye.

CONCLUSIONS:

Irreversible protein cross-linking of transglutaminases via epsilon-(gamma-glutamyl)-lysine connections seem to be indicators for scarring in corneal wound healing. The absence of transglutaminases and their reaction product epsilon-(gamma-glutamyl)-lysine in a LASIK-treated cornea supports the idea of missing scar tissue formation after LASIK surgery.

• Authors: Siegfried G Priglinger, Christian-Albrecht May, Claudia S Alge, Armin Wolf, Aljoscha S Neubauer, Anselm Kampik, Ulrich Welge-Luessen
• Journal: Journal of cataract and refractive surgery (J Cataract Refract Surg) Vol. 31 Issue 7 Pg. 1403-8 (Jul 2005) ISSN: 0886-3350 [Print] United States
• PMID: 16105614 (Publication Type: Journal Article)

Chemical References

• Dipeptides
• Extracellular Matrix Proteins
• epsilon-(gamma-glutamyl)-lysine
• Protein Glutamine gamma Glutamyltransferase 2
• Transglutaminases
• GTP-Binding Proteins

Topics

• Adult
• Cicatrix (metabolism)
• Cornea (metabolism)
• Corneal Injuries
• Dipeptides (metabolism)
• Extracellular Matrix Proteins (metabolism)
• Eye Injuries, Penetrating (metabolism)
• Fluorescent Antibody Technique, Indirect
• GTP-Binding Proteins (metabolism)
• Humans
• Keratomileusis, Laser In Situ
• Keratoplasty, Penetrating
• Male
• Middle Aged
• Myopia (surgery)
• Protein Glutamine gamma Glutamyltransferase 2
• Tissue Donors
• Transglutaminases (metabolism)
• Wound Healing (physiology)