Apoptosis Factors of Lens Epithelial Cells Responsible for Cataractogenesis in Vitrectomized Eyes with Silicone Oil Tamponade

BACKGROUND The aim of this study was to determine the expression of apoptotic factors Bax, Bcl-2, and Caspase-3 in lens epithelial cells (LECs) from cataracts secondary to pars plana vitrectomy with silicone oil (SO) tamponade. We also investigated the impact of SO emulsification on the expression of apoptotic factors. MATERIAL/METHODS Anterior capsulotomy specimens of 20 eyes in 20 patients with cataract secondary to SO tamponade (Group 2), were collected. Another 20 eyes of 20 patients with age-related cataract (Group 1) were recruited as controls. The anterior capsule specimens were obtained from the patients during cataract surgery, frozen and later analyzed with respect to immunohistochemical stains of Bax, Bcl-2, and Caspase-3 using a confocal microscope. RESULTS Age, sex, and laterality did not show any difference between the 2 groups. There was a greater increase in Bax and Caspase-3 expression in LEC in Group 2 than in Group 1 (P(Bax)<0.0001, P(Caspase-3)<0.0001). The Bcl-2 expression decreased in Group 2, although the difference was not significant (P=0.616). The changes of apoptosis factors are not associated to SO emulsification (P(Bax)=0.354, P(Bcl-2)=0.728, P(Caspase-3)=0.939). CONCLUSIONS The caspase-3-dependent apoptosis of LECs increased in complicated cataract patients with SO endotamponade. The Bax played a critical role in regulating apoptosis of LECs in vitrectomized eyes with SO tamponade. The SO emulsification had no significant impact on the expression of apoptosis factors.