Publication Date: 2013.
PURPOSE. To investigate whether tissue plasminogen activator (tPA) can prevent and/or reverse steroid-induced IOP elevation in an ovine model. METHODS. Three animal groups were subjected to bilateral steroid-induced IOP elevation using thrice daily topical ocular prednisolone administration. In the first group (N ¼ 8), one eye each of two sheep was injected intravitreally with 100 lg, 200 lg, 500 lg, or 1 mg human recombinant tPA, while contralateral eyes received vehicle. In the second group (N ¼ 2), one eye was injected intravitreally with tPA (100 lg), while contralateral eyes received vehicle containing L-arginine. In the third group (N ¼ 4), each animal received intravitreal tPA in one eye concurrently with initiation of bilateral steroid administration. IOP was monitored for the duration of the experiment. Tissues from eyes of the third group were used to determine relative gene expression. RESULTS. In the first and second groups, IOP decreased by 9.7 (62.8) and 9.7 (61.6) mm Hg, respectively, 24 hours after tPA administration. In the third group, tPA-treated eyes did not develop IOP elevation with DIOP of 11.8 (61.3) mm Hg 8 days later. In all tPA-treated eyes, IOP remained low until the end of the study. mRNA levels in the trabecular meshwork were decreased for plasminogen activator tissue (PLAT), increased for matrix-metalloproteinase 1 (MMP-1), and stable for plasminogen activator inhibitor 1 (PAI-1), MMP-2, MMP-9, and MMP- 13 in tPA-treated eyes compared with contralateral controls. PAI-1 mRNA levels in ciliary processes also remained similar. CONCLUSIONS. Recombinant human tPA is effective in both preventing and reversing steroidinduced IOP elevation in sheep. Tissue plasminogen activator may be useful as a therapeutic agent in steroid-induced glaucoma.
Author affiliation: Gerometta, Rosana María del Rosario. University Of New York; Estados Unidos. Universidad Nacional del Nordeste. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Author affiliation: Kumar, Sandeep. State University Of New York; Estados Unidos
Author affiliation: Shah, Shaily. State University Of New York; Estados Unidos
Author affiliation: Alvarez, Larry. State University Of New York; Estados Unidos
Author affiliation: Candia, Oscar. State University Of New York; Estados Unidos
Author affiliation: Danias, John. State University Of New York; Estados Unidos
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas