The Survival of Freely Grafted Orbital Fat on Porous Polyethylene Orbital Implants in the Rabbit

PURPOSE To investigate the long term survival of orbital fat grafted on a Medpor implant as a method of preventing porous polyethylene orbital implant (Medpor) exposure in anophthalmic sockets. METHODS In one orbit in each of 8 rabbits, a small amount of retrobulbar orbital fat was grafted between the anterior surface of the Medpor implant and overlying conjunctiva, during the enucleation and Medpor implantation procedure. Two rabbits were sacrificed at 2, 4, 8 and 12 weeks postoperatively and grafted orbital fats were examined by light microscopy. RESULTS Grafted orbital fat was well-maintained at 2 and 4 weeks, postoperatively. However, fat amounts were significantly reduced at 8 weeks, and viable fat was barely visible at 12 weeks. CONCLUSIONS In rabbits, orbital fat grafted on Medpor implants was gradually resorbed, and the fat-occupied volume was not maintained.