Abstract:

To observe the apoptosis of corneal epithelium in ReisBücklers corneal dystrophies (RBCD), and to explore the role of apoptosis in the pathogenesis of ReisBücklers corneal dystrophies. MethodsCornea buttons were obtained from 4 RBCD patients (with R124L mutation of TGFBI gene) in 2 pedigrees who underwent lamella or penetrating keratoplasty. Sections with HE and special staining were observed by light microscopy. Ultrathin sections were performed and ultrastructure changes were investigated under a transmission electron microscope. Terminaldeoxynucleotidyl transferase mediated nick end labeling (TUNEL) staining technique was used to examine the apoptosis of the cornea. Four normal cornea specimens served as controls. ResultsIn the RBCD cornea epithelium, microvilli were decreased or lost. Small clumps of deposits with a high electron density were found between basal cells. Some basal cells had apoptotic signs. A great quantity of rodshape deposits was seen in the Bowman′s layer and the anterior part of the stroma. Apoptosis was found in the corneal basal epithelium by TUNEL staining with a positive rate of（15.02±3.09）%. There was a significant difference between RBCD and normal cornea（P＜0.01）. ConclusionApoptosis of corneal basal epithelium in RBCD patients may be one of the reasons for abnormal deposit in the Desement membrane and clinical symptoms.

Key words: Corneal dystrophies/hereditary; Apoptosis; Histopathology; Microscopy/electron