Risk prediction of posttraummatic enophthalmos development on the basis of orbital volume calculations using multislice computed tomography data

Abstract

Purpose. To elaborate a method of orbital volume measurement in patients with midface trauma at pre- and postoperative stages on the basis of multislice computed tomography (MSCT); to investigate the capabilities of orbital volume measurement to acquire additional diagnostic information and to estimate the risk of postoperative enophthalmos development. Materials and methods. A total of 71 patients (100%) with midface trauma were examined at the Sechenov University clinic. At pre- and postoperative stages, all patients (n = 71, 100%) were examined using MSCT (Toshiba Aquilion One 640) with 0.5 mm slice thickness in bone and soft tissue regimen. To measure orbital volume, MSCT data were processed using Vitrea workstation: bone borders of the right and left orbit were marked before and after surgical treatment on every axial slice, and orbital volumes were presented in ml. Results. Preoperative MSCT data management revealed increased orbital volume due to orbital trauma in 64 patients (90%), the difference between healthy and traumatized orbit was between 2 ml and 14 ml. In these patients, reconstructive surgical procedure was performed. In 7 patients (10%) with mild midface trauma, the difference between orbital volumes was less than 2 ml, this was considered as a positive prognostic factor, and these patients were not subjects to surgical treatment. After surgery, in 55 patients (77%) the orbital volume restored, the difference between orbital volumes was less than 2 ml. In 9 cases (13%), the difference in orbital volume was more than 2 ml, considered as adverse prognostic factor which means that there still was a risk of postoperative enophthalmos development. In this patient group, additional diagnostic examination was necessary, and patients required planning of residual enophthalmos surgical correction with MSCT control during the post-op period. Conclusion. Postprocessing of the MSCT data gave the possibility to calculate pre-and postoperative orbital volume changes and present it in mathematical units (ml) in 3D mode. As the result the additional information can be acquired in order to identify the risk of postoperative enophthalmos.