[Changes in the indications and techniques in the surgery of retrobulbar orbital tumours (author's transl)].

In the past 3 decades, surgery of retrobulbar tumours was mainly done by neurosurgeions (transfrontal orbital approach) or ENT surgeons (transethmoidal approach), especially in Europe. More recently, especially in USA this has changed and the majority of these cases, in an increasing number of hospitals, are now treated by a modified Krönlein operation, usually performed by ophthalmic surgeons. In this paper we tried to elucidate the background of this development. Ultrasound exophthalmometry (Fig. 3), ultrasound A- and B-scans of the orbital tissues (Fig. 4 and 5) and computerized axial X-ray-tomography of the orbits (Fig. 6) improved the preoperative diagnoses markedly. In the most cases it is now possible to decide preoperatively on the existence, size and location (and sometimes even on the nature) of a spaceoccupying lesion in the orbit. The technic and the instruments for Krönlein's operation have been improved (Krönlein-Berke, Fig. 8-11). The oscillating saw (Stryker) facilitates the resection of the bone, and microsurgical technics are now preferred for removal of the tumour from the orbit. The modified Krönlein operation is also recommended for orbital decompression in severe endocrine exophthalmos, provided the lateral orbital wall is removed to the described extent.