The Association of Cataract and Lens Epithelial Cell Apoptosis in Patients with Pseudoexfoliation Syndrome

Purpose: The aim of this study was to measure the density of apoptotic lens epithelial cells (LECs) and to determine its association with cataract formation in eyes with pseudoexfoliation syndrome (PEX). Materials and Methods: Twenty-one eyes of 21 patients diagnosed with PEX without glaucoma (Group 1) and 22 eyes of 22 subjects without PEX (Group 2) were enrolled in this study. During cataract surgery, anterior capsule samples were obtained by the 5.5mm continuous curvilinear capsulorhexis method. Apoptosis was determined with a TUNEL kit (Boster, Wuhan, China) according to the manufacturer's protocol. Four fields in each pathology preparation were chosen randomly under a microscope, and 100 cells were counted in each field to calculate the apoptosis rates. Results: Forty-three eyes of 43 subjects were enrolled in this study. There were no significant differences in age or sex between the two studied groups (p > 0.05). Under a microscope, the LECs were stained light blue and their nuclei were oval shaped. Positive stained cells were found occasionally in Group 2, while a significant amount of black-brown positively stained LECs with condensed nuclei was found in Group 1. The apoptosis rates were 35.2 +/- 2.1% and 14.1 +/- 1% in Groups 1 and 2, respectively. The proportion of positively stained LECs was higher in Group 1 (p < 0.001). Conclusion: Our study suggests that apoptosis in LECs is the pathophysiological mechanism for the higher rate of cataracts in PEX patients, in addition to the ocular ischemia hypothesis.