Abstract
Purpose::
The hydrogel orbital expander (Osmed GmbH, Illmenau, Germany, distributed in United States by IOP, Inc., Costa Mesa, CA) is a relatively new implant designed to provide orbital volume after implantation through a small soft tissue incision. The implant consists of a highly hydrophilic polymer that expands osmotically. Some of these favorable characteristics are countered by potential shortcomings including long term intraorbital erosions, fibrosis, granuloma formation, and extrusion. We report four cases of postoperative migration of these implants
Methods::
We reviewed the charts of four patients treated with a hydrogel expander orbit implant in the same technique. The indications for the procedure, the surgical technique, and details of the implant migration such as final implant location were investigated.
Results::
All four implants extruded at an average 5 months postoperative. The average age at implantation was 5 years old. One implant was implanted primarily while three were implanted secondarily after removal of a failed primary implant or an implant that was not of adequate size in relation to the orbit. The final inferolateral, extraconal position of the implant was similar in all patients. In all cases, the final appearance of the implant was spherical with no abnormalities of contour or surface integrity. No case was complicated by infection.
Conclusions::
While the Osmed hydrogel expander produced excellent intraoperative and immediate-post operative results in each patient, the final expanded implant was situated inferotemporally and outside the muscle cone. While the exact extrusion rate is yet unknown, we suspect that the rapid rate of expansion and not wrapping the implant (e.g. with sclera) contribute to implant migration in the path of least resistance. Further investigation regarding implantation technique and the complication rate of the Osmed expander is warranted.
Keywords: orbit • wound healing