[Combined use of computerized tomography and echography in ophthalmology (author's transl)].

Computerized tomography does not give as fine an information as echography in the presence of intraocular changes, such as retinal detachments, organized vitreous hemorrhages or the differentiation of a choroidal prominence. Complementary computerized tomography, however, can be helpful in the presence of unclear echographic results in opaque media. Furthermore, an analysis of the value of computerized tomography and echography for the evaluation of orbital lesions is presented based mainly on the results of the preoperative tissue diagnosis in 31 histological proven lesions. The results show that a complementary CT-scan is not necessary in orbital lesions of the anterior third when a clear echographic tissue diagnosis exists. In lesions of the middle third of the orbit, echography and CT complement each other. For lesions situated within the orbital apex or for those which are in connection with adjacent structures, such as the intracranial space or the periorbital region, computerized tomography is superior and of a greater help than standardized A-scan echography aided by contact B-scan.