Design of a magnetically integrated microporous implant

Abstract

Objective: To determine the orbital tolerance of a microporous implant fitted with an integrated stainless steel post and the enhanced motility associated with magnetic coupling of the prosthetic and the implant in a rabbit model. Methods: Six New Zealand white rabbits underwent primary enucleation with implantation of a 12-mm microporous polyethylene implant with a 2 x 3-mm stainless steel post embedded flush with the anterior surface. At 1 month, the rabbits were fitted with an external prosthesis containing two 1-mm circular 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 with a hanging block technique. Results: No evidence of toxicity was observed in association with this integrated ocular implant. Magnetic coupling forces were noted maximally at 0.47 N. Clinical grading of motility documented enhancement in lateral excursion when compared with nonintegrated controls. Conclusion: Magnetically integrated microporous implants achieve excellent enhancement of motility without evidence of complications in this rabbit model. Clinical Relevance: This study establishes a framework for the clinical evaluation of a magnetically integrated implant that may enhance prosthetic motility without requiring direct mechanical coupling of the implant to the prosthesis.