Ocular Implants and Devices

Of the different ocular implants, lens implants, and devices tested in the MR environment, the Fatio eyelid spring, the retinal tack made from martensitic (i.e., ferromagnetic) stainless steel (Western European), the Troutman magnetic ocular implant, and the Unitek round wire eyelid spring demonstrated positive magnetic field interactions in association with exposure to 1.5-Tesla MR systems. By comparison, many of the lens implants pose no hazard to the patient during an MRI procedure since they do not contain metallic materials (see The List).

A patient with a Fatio eyelid spring or round wire eyelid spring may experience discomfort but would probably not be injured as a result of exposure to an MR system. In fact, patients have undergone MR procedures with eyelid wires after having a protective plastic covering placed around the globe along with a firmly applied eye patch as a precaution.

The retinal tack made from martensitic stainless steel and Troutman magnetic ocular implant may injure a patient undergoing an MR procedure, although no such case has ever been reported.

[For additional information pertaining to ocular related prostheses, see Glaucoma Drainage Implants (Shunt Tubes), Magnetically-Activated Implants and Devices, and Scleral Buckle (Scleral Buckling Procedure.]

REFERENCES
Albert DW, Olson KR, Parel JM, et al. Magnetic resonance imaging and retinal tacks. Arch Ophthalmol 1990;108:320-321.
de Keizer RJ, Te Strake L. Intraocular lens implants (pseudophakoi) and steelwire sutures: a contraindication for MRI? Doc Ophthalmol 1984;61:281-284.
Joondeph BC, Peyman GA, Mafee MF, et al. Magnetic resonance imaging and retinal tacks [Letter]. Arch Ophthalmol 1987;105:1479-1480.
Marra S, Leonetti JP, Konior RJ, Raslan W. Effect of magnetic resonance imaging on implantable eyelid weights. Ann Otol Rhinol Laryngol 1995;104:448-452.
Roberts CW, Haik BG, Cahill P. Magnetic resonance imaging of metal loop intraocular lenses. Arch Ophthalmol 1990;108:320-321.
Seiff SR, Vestel KP, Truwit CL. Eyelid palpebral springs in patients undergoing magnetic resonance imaging: an area of possible concern [Letter]. Arch Ophthalmol 1991;109:319.
Shellock FG. Magnetic Resonance Procedures: Health Effects and Safety. CRC Press, LLC, Boca Raton, FL, 2001.
Shellock FG, Kanal E. Magnetic Resonance: Bioeffects, Safety, and Patient Management. Second Edition, Lippincott-Raven Press, New York, 1996.
Shellock FG, Myers SM, Schatz CJ. Ex vivo evaluation of ferromagnetism determined for metallic scleral “buckles” exposed to a 1.5-T MR scanner. Radiology 1992;185:288-289.