Extruded, partially disintegrated, poly-HEMA orbital implant (AlphaSphere).

A 54-year-old diabetic man underwent enucleation for endophthalmitis. Secondary implantation of a 2-hydroxyethyl methacrylate (HEMA) sphere (AlphaSphere, Addition Technology) was performed 2 weeks later. Six weeks after insertion, noninfectious disintegration of sutured tissue planes represented by Tenon's capsule, rectus muscle, and conjunctiva occurred, requiring removal of the fragmenting implant before uncontrolled extrusion occurred. Histopathologic analysis revealed an absence of infectious pathogens and no tissue necrosis, but rather breakup of the implant material that elicited a granulomatous response with sparse T-lymphocytes and almost no polymorphonuclear leukocytes. This distinctively designed poly-HEMA orbital implant incited a dramatic and irreversible host tissue response. Investigation of other cases will be necessary to determine the frequency of such a complication and should include rigorous histopathologic techniques.