Chronic subperiosteal hematic cyst formation twelve years after orbital fracture repair with alloplastic orbital floor implant.

An 89-year-old female patient with a history of a left orbital floor fracture repair with synthetic implant 12 years prior, presented with a three-week history of blurry vision, inferior conjunctival chemosis and proptosis of the left eye. CT scan revealed a well-circumscribed subperiosteal lesion with superior elevation of the orbital floor implant. The patient underwent transconjunctival orbital surgery with removal of the implant and drainage of the subperiosteal hemorrhagic cyst. The patient had an uncomplicated postoperative course, with resolution of the proptosis, chemosis, and return of normal vision. This case represents an unusual late complication of orbital fracture repair with associated reduced visual acuity.