The Effect of Polyurethane Film with Sustained Release Edxamethasone on Prevention of Experimental Fat Adherence Syndrome in Rabbits

Choi, Dong Gyu; Kwon, Soon Il; Jeong, Seo Young

Abstract

The fat adherence syndrome(FAS) is a severe form of the restrictive strabismus resulting from the adherence of orbital tissues to the globe of extraocular muscles and their attachments, for which no successful treatment currently exists. we developed anexperimental model for the FAS in the rabbit eyes and then evaluated the effects of polyurethane film with sustained release dexamethasone on the prevention of experimental FAS. Thirty eyes of fifteen white rabbits had a fat autograft placed between the inferior rectus and the periosteum of the inferior orbital rim and then, the inferior rectus, the fat and the periosteum were sutured to create an experimental FAS. In Group I the experimental FAS was only induced as a control group. The polyurethane film with no released substance and the polyurethane film with sustained release of dexamethasone were inserted between the inferior rectus and the fat in Group II and Group III, respectively. The force required to move the eyeball superiorly 4mm, 6mm, and 8mm was measured preoperatively and 4 weeks ostoperatively. At postoperative 4 weeks the surgical dissection to evaluate the degree of the adhesion and the histologic examination were performed. A significant increase in forced duction(postop-preop) was found at all levels of ocular rotation in Group I and it means that the induction of experimental FAS was successful. Histology revealed a moderate inflammatory response with partial loss of normal adipose tissue replaced by fibrovascular tissue. Group III had significantly less restriction than Group I and Group II. Group II had less restriction than Group I, but statistically not significant. In conclusion, the use of the polyurethane film with sustained release of dexamethasone may have a role in the prevention of experimental FAS.