[Magnetic resonance tomography in ophthalmologic diagnosis]

First introduced into clinical use in 1981 as an investigative modality, this technique offers a wealth of information about the topography and physicochemical composition of the soft tissues in the orbit and central nervous system. However, to date, some of this information is still not incompletely understood. This method can be used to augment the usual diagnosis methods in selected cases of intraocular tumor. It is possible to differente between Coats disease and non-calcified retinoblastoma, and the paramagnetic properties of melanin allow the melanin content of choroidal tumors to be estimated. However, so far magnetic resonance tomography (MRT) still cannot, be recommended as a routine diagnostic procedure. MRT is of significant help in localizing pathological processes involving the orbital apex. The optic nerve and its surrounding dural sheath can be imaged with consistent reliability as distinctly separate structures. In cases of retrobulbar optic neuritis, the increase in signals by the pathologically involved segments of the optic nerve permits these segments to be differentiated from the adjacent optic nervous tissue that is unaffected. After administration of paramagnetic contrast material, the sinus cavernosus region can be visualized particularly well. Inflammatory and thrombotic processes can be diagnosed better than with the methods previously available. Surgery can be planned more easily in cases of intracranial space-occupying lesions, especially in the region of the chiasmic portion of the optic nerve; thus at present MRT can be viewed as the method of choice in planning the operative treatment of such lesions.