[Surgery of orbital tumor--analysis of location and appropriate operative approaches (author's transl)].

Twenty-six cases of orbital tumor were operated on during the period from 1965 to August, 1978. Pseudotumor was most frequently encountered, accounting for 7 cases followed by optic glioma (5 cases), meningioma (4 cases), mixed tumor (3 cases), hemangioma (3 cases), etc. Orbital venography and CT scan were found to be useful for determination of their location and nature. Most of the orbital tumors were found in the central or upper half of the orbit (62%) in coronal section and retrobulbar position (85%) in sagittal section. Intracranial extension was found in 7 cases (27%), and in 4 cases of the 7, intracranial extension was not suspected even by detailed preoperative examination. This fact indicates the importance of opening the dura mater and inspecting the chiasmal region. We therefore have adopted a frontal intra- and extradural combined approach. Other advantages of this approach were also discussed.