Scientists based in the USA and Germany set out to determine a) the orbital tolerance of a microporous implant fitted with an integrated stainless steel post and b) the enhanced motility associated with magnetic coupling of the prosthesis and the implant.

Six rabbits underwent primary

One month later, the scientists fitted the rabbits with an external prosthesis containing two 1mm circular rare earth dental magnets embedded at 0.5 mm off the midline (right and left of centre at the horizon).

They determined the magnetic coupling forces with a hanging block technique.

The scientists did not find any evidence of toxicity in association with this integrated ocular implant. They found that motility was enhanced in lateral excursion when compared with nonintegrated controls.

From this experiment, they deduce that magnetically integrated microporous implants achieve excellent enhancement of motility without evidence of complications.

As a result, they claim that this study establishes a framework for the clinical evaluation of a magnetically integrated implant that may enhance prosthetic motility without requiring the direct mechanical coupling of the implant to the prosthesis.

Murray, Timothy et al, Archives of Ophthalmology, 118, pp 1259-1262, 2000; contact: Dr Murray at Bascom Palmer Eye Institute, University of Miami School of Medicine, PO Box 016880, Miami, FL 33101, USA; E-mail: tmurray@bpei.med.miami.edu