Human basement membrane components of keratoconus and normal corneas.

Using immunofluorescence techniques, we analyzed the distribution of glycoproteins in normal and keratoconus corneas of humans. Laminin, bullous pemphigoid antigen, fibronectin, and fibrin/fibrinogen were all found in the epithelial basement membrane of normal corneas. Keratoconus corneas produced similar results, except that staining for fibrin/fibrinogen was weak. Fibrin/fibrinogen was absent from normal corneal basement membrane in animal models studied previously. Keratoconus may be the result of the lysis of fibrin or may involve impeded elaboration of fibrin.