Abstract
Purpose :
To determine if tissue plasminogen activator (tPA) can treat postoperative fibrosis and improve the clarity of the visual axis after lensectomy with intraocular lens (IOL) insertion in a juvenile rabbit animal model.
Methods :
All experiments were approved and in compliance with Animal Care Committee at the University of Illinois at Chicago and the Medical College of Wisconsin. 9 juvenile (6-7 week old) New Zealand White rabbits had unilateral lensectomy with intraocular lens insertion under general anesthesia. Clear-cornea lens extraction surgery was performed followed by insertion of an acrylic fIOL (Alcon SN60WF 30D). Topical antibiotic ointment was given for 3 days postoperatively.
Rabbits were examined under sedation postoperatively on days 3 through 7 and on day 14 with slit lamp biomicroscopy and optical coherence tomography (OCT) (Spectralis OCT, Heidelberg Engineering). Anterior chamber inflammation was quantified using the SUN classification system. OCT signal strength was used as a quantification of the clarity of the central visual axis. After examination on day 3, eyes were injected with 25 micrograms of recombinant rabbit tPA (Molecular Innovations) (n=5) or balanced salt solution (control) (n=4) into the anterior chamber.
Results :
Lensectomy with IOL insertion resulted in a fibrin clot and inflammation of the anterior chamber similar to previous reports (1). Compared to controls, tPA injected on day 3 after lensectomy reduced fibrin in the anterior chamber from 64% to 15% (p<0.001) and improved OCT signal strength from 2.88 to 14.4 ( p<0.001) 1 day after treatment. Both measures continued to be improved for the tPA treated group for the remainder of the examination period. Inflammation of the anterior chamber was significantly greater in eyes treated with tPA. There was no increase in the incidence of intraocular bleeding in eyes treated with tPA.
1. Bogaard JD, Kassem IS. Evaluation of therapeutic interventions for postoperative inflammation and fibrosis in a juvenile rabbit model of lensectomy. Invest. Ophthalmol. Vis. Sci.. 2015; 56(7):3217.
Conclusions :
tPA significantly reduces fibrin in the anterior chamber after lensectomy and may be an alternative to surgical removal of fibrin membranes after lensectomy.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.