Histologic evaluation in rabbits of the biocompatibility of episcleral implant material: S-PTFEe (silicone core covered with expanded polytetrafluoroethylene)]

To study the tolerance of a silicone band wrapped with expanded polytetrafluoroethylene (e-PTFE) in "fauve de Bourgogne" rabbits.A 5.7mmx3.2mm band of S-PTFE (silicone-polytetrafluoroethylene, France Chirurgie Instruments) was used. A tight seal was produced between the two materials by silicone gluing. Eight eyes were implanted episclerally and fixed with Mersilene 5-0. One silicone band was used on a control eye.Three eyes were removed at 4 weeks, one at 8 weeks and four at 12 weeks. No extrusion was observed except for the silicone band rejected 2 weeks after implantation. On histopathologic examination, PTFE colonisation was present in all eyes with fibroblast, inflammatory cells, and neovascularization.The S-PTFE implant was colonized and well tolerated in rabbit eyes. Advantages of silicone band (quality, stability of indentation) are combined to the tolerance of PTFE.