The Evaluation of TUNEL, PCNA and SOX2 Expressions in Lens Epithelial Cells of Cataract Patients with Pseudoexfoliation Syndrome

Purpose: This study aims to determine the expression patterns of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), proliferating cell nuclear antigen (PCNA) and SOX2 in lens epithelial cells (LEC) of cataract patients with pseudoexfoliation syndrome (PEX), and to determine the effect of apoptosis, proliferative activity and stem/progenitor cells on cataract formation in patients with PEX. This is a prospective, randomized clinical trial. Materials and Methods: Setting: institutional. 50 eyes of 50 patients were included. Anterior capsule samples were obtained during phacoemulsification surgery. The specimens of LEC were also examined using the TUNEL, PCNA and SOX2 immunohistochemical staining method. To detect the number of immunopositive cells, the total number of cells in a 3 mm(2) area was counted using a microscope under x20 magnification and the percentage of cells stained positive was determined. Results: In Group 1, increased expression was observed with TUNEL, while decreased expression was detected with PCNA (p = .008, p = .015). The average percentage of TUNEL immunopositive cells was significantly higher in Group 1 than in Group 2, but there was no statistically meaningful SOX2 expression in Group 1 and Group 2 (P = .44). Apoptosis rates were 61.75 +/- 14.5% and 36.91 +/- 14.6% in Groups 1 and 2, respectively. Proliferation rates were 40.96 +/- 16.8% and 65.45 +/- 16.9% in Groups 1 and 2, respectively. Conclusion: We found increased apoptosis and decreased proliferation of LECs in cataract patients with PEX. We suspected that this could be related to oxidative stress.