Magnetized forceps for intraocular foreign body removal: which one is suitable?

IntroductionMagnetic intraocular foreign bodies can be removed with magnetized disposable forceps. Aim of this study is to compare the forceps magnetizability of different size, form and manufacturer.MethodsThe forceps were magnetized using an established procedure. The inducible magnetic flux density was measured at the tip of the forceps. The mass that can be lifted with the magnetized forceps was then tested using steel balls in BSS solution. The weight of the metal parts of the forceps was measured.ResultsThe magnetic flux density that could be induced, the weight of the steel balls that could be lifted and the mass of stainless steel used in the forceps were as follows: Alcon end-grasping 23G: 7.12 mT, 87.43 mg, 1191 mg; Alcon end-grasping 25G: 6.43 mT, 87.43 mg, 1189 mg; Alcon serrated: 4.39 mT, 63.78 mg, 1284 mg; Alcon serrated 23G: 3.62 mT, 13.74 mg, 1200 mg; Alcon serrated 25G: 2.4 mT, 13.74 mg, 1195 mg; DORC end-grasping 23G: 5.52 mT, 32.54 mg, 153 mg; Synergetics end-grasping 23G: 4.35 mT, 16.37 mg, 193 mg; Vitreq BV end-grasping 23G: 2.65 mT, none, 88 mg.DiscussionThe magnetizability of a disposable microforceps seems to depend on the mass of steel at the tip of the forceps. The structure of the iron lattice could have an even greater influence. Not every disposable forceps can be sufficiently magnetized for this technique. What is known:center dot Steel intraocular foreign bodies can be lifted with magnetized forceps.What is new:center dot Not every forceps can be magnetized sufficiently.center dot Whether forceps can be magnetized well or poorly seems to have less to do with the stainless steel mass of the forceps.center dot The iron lattice structure of the used steel could be responsible for the magnetizability of the forceps.