The expression of all six chains of collagen IV was studied using the indirect fluorescent immunohistochemistry in seven control corneas and seven corneas obtained from patients suffering from the posterior polymorphous corneal dystrophy. Heterogeneous staining, especially in the epithelial basement membrane and Descemet's membrane, was observed in the control corneas. An increase of the staining intensity for the alpha1 and alpha2 chains was observed, especially in the Descemet's membrane and the corneal stroma in samples obtained from the patients compared to the control tissues.