Use of Polyurethane with Sustained Release Dexamethasone in Delayed Adjustable Strabismus Surgery

ABSTRACT

PURPOSE: To determine the effect of polyurethane with sustained release dexamethasone in delayed adjustable strabismus surgery in rabbits. METHODS: After recession of the superior rectus muscle(SRM), balanced salt solution or polyurethane film with/without sustained release dexamethasone was applied beneath and over the SRM in the control group(group C), polyurethane-steroid group(group P-S) and polyurethane group(group P), respectively. Delayed adjustment was performed once on each SRM at four and six weeks postoperatively by a masked observer. The possible length to adjust and the necessary force required for the adjustment, as well as the degree of any adhesions, were also evaluated. RESULTS: In the control group, adjustment was impossible in all of the eyes at four and six weeks postoperatively. In group P-S, adjustment was possible in 11 out of 11(11/11) eyes four weeks postoperatively and in 10/11 eyes six weeks postoperatively. In group P, adjustment was possible in 9/11 eyes four weeks postoperatively and in 10/12 eyes six weeks postoperatively. In addition, the degree of adhesion was significantly less in group P and in group P-S compared to the control group. The degree of adhesion between the SRM and the sclera was marginally better(p=0.051) in group P-S four weeks postoperatively than in group P. CONCLUSIONS: Use of polyurethane film could delay adjustment in most of the rabbit eyes for up to six weeks postoperatively. Sustained release dexamethasone is helpful for delaying adjustment in rabbit eyes until six week postoperatively without the need for frequent topical instillation of steroids.