Interpositional polytetrafluoroethylene grafts. Conjunctival biocompatibility.

Polytetrafluoroethylene (PTFE) is a synthetic, woven, nonabsorbable, nonantigenic, Teflon-related material that has been shown to be useful in correcting eyelid retraction and as an implant enveloping material in primary and secondary surgery to correct anophthalmos. Implanted PTFE will extrude if not entirely covered with a layer of conjunctival epithelium. In vitro studies demonstrated that coating PTFE with collagen, fibronectin, gelatin, or laminin promotes epithelial cell and fibroblast migration over and adherence to PTFE. In vivo studies showed that a coating of type 1 collagen is most successful in preventing graft extrusion by promoting conjunctival epithelial attachment and growth over exposed PTFE. Further studies are needed to determine the optimum PTFE coating and pore size needed to ensure the consistent retention of uncovered implanted PTFE grafts.