MOBILIZATION OF INTRAOCULAR FOREIGN-BODIE S BY MAGNETIC-RESONANCE-IMAGING

A 49-year-old patient suffered from a binocular perforating trauma wit h metal foreign bodies in 1974. During an MRI examination in 1992 for a lumbar spine herniation a metal foreign body was mobilised from the deeper vitreal and retinal area, now causing optical disturbances free ly floating in the anterior vitreous. Refusing an operation, the patie nt, an electrical engineer, tried himself to remove the foreign body o ut of the optical axis by exposing his head to the electro-magnetic fi eld of an induction coil (pulsed magnetic induction B at t(0) of 0.26 Tesla). The foreign body was split into multiple small parts no longer disturbing the patient. To early detect a siderosis regular ophthalmo logical controls including ERG are necessary. This example stresses th at even small intraocular metall foreign bodies are a contraindication for the usually applied field strength of MRI examinations.