INCREASED EXPRESSION OF FIBRILLIN-1 IN HUMAN CORNEAS WITH BULLOUS KERATOPATHY

Purpose. To characterize the expression of fibrillins, microfibril com ponents, in human corneas with pseudophakic/aphakic (PBK/ABK) bullous keratopathy. Methods. Normal and PBK/ ABK corneas were stained by immu nofluorescence for fibrillin-1 and -2. The expression of fibrillin-1 m essenger RNA (mRNA) was studied by semiquantitative reverse transcript ion-polymerase chain reaction (RT-PCR) and Southern analysis. Results. Only fibrillin-1 was detected in normal and diseased corneas. As desc ribed previously, in normal corneas, it was found in the limbal stroma and basement membrane (BM) and in the peripheral corneal epithelial B M for a short distance near the limbus. Central corneal BM, stroma, an d Descemet's membrane were negative. All PBK/ABK corneas were positive for fibrillin-1, which was detected in fibrillar deposits at the endo thelial face of Descemet's membrane, in the epithelial BM, subepitheli al fibrosis areas, and posterior collagenous layer. By RT-PCR, low lev els of fibrillin-1 mRNA were detected in normal corneas, and they incr eased significantly in PBK/ABK corneas. Conclusion. The deposition of fibrillin-1, together with tenascin-C, in PBK/ABK corneas may be part of an abnormal fibrotic/wound-healing process that occurs during the d evelopment of postsurgical corneal edema with the formation of bullae and posterior collagenous layer.