Figure 1.

Example of orbital volume measurement using ‘The Eclipse Treatment Planning System (Ver 13.0, Varian)'. Axial plane: the anterior orbital boundary was defined by a straight line connecting the medial and the lateral orbital rims, and the posterior limit was defined as the orbital apex. Coronal plane: the anterior orbital boundary was defined as the CT slice in which 50% of the inferior orbital rim was visible, and the posterior limit was defined as the orbital apex. Sagittal plane: the anterior orbital boundary was defined by the straight line connecting the superior and inferior orbital rims, and the posterior limit was defined as the orbital apex. The areas of these outlines were measured on each scan and summed to obtain orbital volumes. (a) Preoperative. The red arrow indicates a left inferior wall fracture and herniated orbital tissue before surgery. (b) Postoperative. The green arrow indicates reconstructed left inferior wall fracture. Postoperative image shows reduction of the displaced orbital wall and herniated orbital tissue.