摘要：Objectives. To determine safe distances within the orbit outlining reliable operative area on the basis of multislice computed tomography (MSCT) scans. Patients and Methods. MSCT of orbits of 50 Caucasian patients (26 males and 24 females, mean age 56) were analysed. Native scans resolutions were in all cases 0.625 mm. Measurements were done in postprocessing workstation with 2D and 3D reconstructions. The safe distances values were calculated by subtracting three standard deviations from the arithmetical average . This method was chosen because this range covers 99.86% of every population. Results. The results of the measurements in men and women, respectively, are as follows (1) distance from optic canal to supraorbital foramen, mean 46,49 mm and 43,29 mm, (2) distance from the optic canal to maxillozygomatic suture at the inferior margin of the orbit mean 45,24 mm and 42,8 mm, (3) distance from the optic canal to frontozygomatic suture 46,15 mm and 43,58 mm, (4) distance from the optic canal to anterior lacrimal crest 40,40 mm and 38,39 mm, (5) distance from superior orbital fissure to the frontozygomatic suture 34,06 mm and 32,62 mm, and (6) distance from supraorbital foramen to the superior orbital fissure 42,32 mm and 39,39 mm. Conclusion. The most probable safe distances calculated by adopted formula were for the superior orbital fissure 23,39–30,58 mm and for the orbital opening of the optic canal 31,9–38,0 mm from the bony structures of the orbital entrance depending on the orbital quadrant.
