Keratocyte apoptosis in keratoconus

: Analysis of 37 corneal disks removed in perforating keratoplasty for stages II-IV keratocone and of 15 corneal disks (control) from subjects dead from mechanical injuries at the age of 17-35 years was carried out. The expression of CD95 receptors on keratocyte membranes was evaluated by indirect immunofluorescent label using rabbit antibodies. Keratocyte apoptosis was evaluated by indirect immunofluorescent labeling of nuclear DNA nucleotides. Estimation of the volumic share of keratocytes expressing CD95 on cell membrane showed it to be almost 8-fold higher and apoptosis index almost 5-fold higher in the keratocone corneal disks than in the control. The results indicate the presence of a Fas-mediated mechanism of keratocyte apoptosis and its manifold predominance in the cornea in keratocone. These results are clinically significant for the choice of pathogenetic therapy of patients with keratocone.