To the Editor.
—Magnetic resonance imaging (MRI) is becoming a common diagnostic tool in medicine, supplementing and at times replacing computed tomography. There is concern about the safety of MRI in patients with intraocular metallic objects, namely, retinal tacks. Retinal tacks have recently been described as an adjunct in the repair of complicated retinal detachments.1,2 They allow immediate retinal fixation while more permanent fixation from diathermy, laser photocoagulation, or cryopexy develops. We studied the effect of MRI scanning on two types of retinal tacks currently in use.
Materials and Methods.
—A titanium retinal tack (Cooper-Vision, Irvine, Calif) and a cobalt-nickel tack (Grieshaber, Fallsington, Pa) were used in the study. These tacks are approximately 3 mm long. The cobalt-nickel tack is composed of an alloy containing 45% cobalt and 23% nickel by weight and has been approved for surgical implantation.2 As a control, 3-mm sections of a ferromagnetic paper
Joondeph BC, Peyman GA, Mafee MF, Joondeph HC. Magnetic Resonance Imaging and Retinal Tacks. Arch Ophthalmol. 1987;105(11):1479-1480. doi:10.1001/archopht.1987.01060110025012