COLLAGEN-SYNTHESIS IN LENS EPITHELIAL-CELLS ON CAPSULES CONTAINING INTRAOCULAR-LENS IMPLANTS IN RABBITS - IMMUNOLOCALIZATION OF PROLYL 4-HYDROXYLASE

Background: We evaluated ultrastructurally the presence and distributi on of lens epithelial cells and extracellular matrix on the posterior capsule after implantation of a silicone or a polymethylmethacrylate ( PMMA) intraocular lens (IOL) in rabbits. The immunolocalization of pro lyl 4-hydroxylase, an enzyme involved in procollagen synthesis, was al so examined in such cells. Methods: Anesthetized adult albino rabbits (n=12) underwent phacoemulsification and aspiration (PEA) of the cryst alline lens and implantation of a silicone or a PMMA IOL into the caps ular bag of one eye. They were killed by an intravenous overdose of pe ntobarbital sodium. The lens capsules were processed for transmission electron microscopy and for immunohistochemical detection of the beta- subunit of prolyl 4-hydroxylase. Results: Ultrastructurally, lens epit helial cells on the posterior capsule evidenced an accumulation of col lagenous extracellular matrix. Prolyl 4-hydroxylase immunoreactivity w as detected in the cytoplasm of cells distributed on the capsules. Con clusion: Lens epithelial cells are involved in the production of colla genous matrix on lens capsules after PEA and implantation of IOL, resu lting in a fibrotic process of the lens capsule.