Advanced glycation end-products in corneas of patients with keratoconus

Background: Keratoconus remains a poorly understood yet widespread disease which poses a potential threat to human vision. The underlying mechanisms are still not clear. One possible pathway is increased formation and accumulation of advanced glycation end-products (AGEs) in the cornea. Methods: Corneas obtained from six patients with keratoconus and from six healthy controls were investigated. An immunohistochemical localisation of the well-known AGE N-epsilon-carboxymethyllysine (CML) was performed using a polyclonal anti-CML antibody. Results: In the corneas of all six patients with keratoconus, CML immunoreactivity was found in the epithelial as well as in the endothelial cells. The keratocytes also showed a positive reaction. The controls, in contrast, showed very little or no immunoreactivity. Conclusion: In the epithelial, stromal and endothelial cells of corneas with keratoconus an accumulation of CML was detected which might play a role in the pathogenesis of keratoconus.