Design of a magnetically integrated microporous implant

Objective: To determine the orbital tolerance of a microporous implant fitt ed with an integrated stainless steel post and the enhanced motility associ ated with magnetic coupling of the prosthetic and the implant in a rabbit m odel. Methods: Six New Zealand white rabbits underwent primary enucleation with i mplantation of a 12-mm microporous polyethylene implant with a 2 x 3-mm sta inless steel post embedded flush with the anterior surface. At 1 month, the rabbits were fitted with an external prosthesis containing two 1-mm circul ar rare earth dental magnets embedded at 0.5 mm off the midline (right and left of center at the horizon). Magnetic coupling forces were determined wi th a hanging block technique. Results: No evidence of toxicity was observed in association with this inte grated ocular implant. Magnetic coupling forces were noted maximally at 0.4 7 N. Clinical. grading of motility documented enhancement in lateral excurs ion when compared with nonintegrated controls. Conclusion: Magnetically integrated microporous implants achieve excellent enhancement of motility without evidence of complications in this rabbit mo del. Clinical Relevance: This study establishes a framework for the clinical eva luation of a magnetically integrated implant that may enhance prosthetic mo tility without requiring direct mechanical coupling of the implant to the p rosthesis.