Increased expression of fibrillin-1 in human corneas with bullous keratopathy

Purpose. To characterize the expression of fibrillins, microfibril components, in human corneas with pseudophakic/aphakic (PBK/ABK) bullous keratopathy. Methods. Normal and PBK/ABK corneas were stained by immunofluorescence for fibrillin-1 and -2. The expression of fibrillin-1 messenger RNA (mRNA) was studied by semiquantitative reverse transcription- polymerase chain reaction (RT-PCR) and Southern analysis. Results. Only fibrillin-1 was detected in normal and diseased corneas. As described previously, in normal corneas, it was found in the limbal stroma and basement membrane (BM) and in the peripheral corneal epithelial BM for a short distance near the limbus. Central corneal BM, stroma, and Descemet's membrane were negative. All PBK/ABK corneas were positive for fibrillin-1, which was detected in fibrillar deposits at the endothelial face of Descemet's membrane, in the epithelial BM, subepithelial fibrosis areas, and posterior collagenous layer. By RT-PCR, low levels of fibrillin-1 mRNA were detected in normal corneas, and they increased 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 development of postsurgical corneal edema with the formation of bullae and posterior collagenous layer.