Cyst formation associated with porous polyethylene orbital floor implant.

A 28-year-old female presented with hyperglobus and inferior scleral show after the repair of an orbital floor fracture using a porous polyethylene (Medpor) implant. CT revealed a large inferior orbital cystic mass displacing the globe. The cyst was explored and excised and the implant was found to be free from any attachment to surrounding tissues and hence, removed without difficulty. The reason for the cyst development was most likely inadvertent epithelial inclusion at the time of surgery-a recognized risk with insertion of any foreign body via transconjunctival approach. Porous implants when placed in the subperiosteal space might not get incorporated with surrounding tissues and therefore behave like any traditional nonporous alloplastic material.