Of the different ocular implants, lens implants, and devices that have undergone MRI testing, 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 1.5-Tesla MR systems. By comparison, many lens implants pose no hazard to the patient during an MRI procedure since they are not made from metallic or conducting 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 examinations 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. Interestingly, Tokue, et al. (2013) reported that certain color contact lenses (which are a type of cosmetic contact lens) may contain iron oxide or other metals, which is problematic for MRI due to the associated imaging artifacts. 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. Allemann R, et al. Ultra high-field magnetic resonance imaging of a glaucoma microstent. Curr Eye Res 2011;36:719-26. 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, et al. 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, et al. 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. Tokue H, et al. Incidental discovery of circle contact lens by MRI: You can't scan my poker face, circle contact lens as a potential MRI hazard. BMC Med Imaging 2013;13:11. van Rijn GA, et al. Magnetic resonance compatibility of intraocular lenses measured at 7 Tesla. Invest Ophthalmol Vis Sci 2012;53:3449-3453. |