Distribution of specific collagen types and fibronectin in normal and keratoconus corneas.

The distribution of five types of collagen and fibronectin in 6 normal and 9 keratoconus corneas was examined, using immunofluorescent staining and the enzyme-labeled antibody method. Types I, III and V collagens were detected in the corneal stroma. There was essentially no difference between normal and keratoconus corneas in their distribution. Type IV collagen and fibronectin were detected in the basement membrane of the normal corneal epithelium, while in the keratoconus corneas the disruption of the basement membrane as well as the excrescence of basement membrane materials was observed. The abnormal distribution of the type IV collagen and fibronectin was also observed in the anterior stromal area of keratoconus corneas.