Liquid silicone oil is used in ophthalmology as a possible substitute of the vitreous body and the internal tamponade of the vitreous body space in pars plana vitrectomy (PPV). The presence of silicone in the eye causes marked changes in the CT image of the bulbus. As the number of patients treated by PPV is steadily increasing (this pertains in particular to patients with diabetes mellitus and AIDS), the probability that the radiologist will encounter this image is increasing. Typical changes of the CT image of the bulbus after PPV using silicone cerclage bands with administration of silicone oil (SO) into the vitreous body space: 1. disfiguration of the bulbus after application of the cerclage band, 2. the area of the vitreous body is visualized as a hyperdense area with a slit- -shaped space between the SO and the bulbar wall. Knowing these changes, errors in the interpre- tation of CT images incl. those recorded at random can be avoided.

        Key words: CT - bulbus - PPV - silicone oil - AIDS