Does Orbital Volume Change Using the Mirror Technique Have a Correlation With Posttraumatic Enophthalmos?

An increase in orbital volume (OV) is an important factor in posttraumatic enophthalmos. The aim of this study was to evaluate the correlation of OV change using the mirror technique with posttraumatic enophthalmos. In this cross-sectional study, a 3-dimensional (3D) semi-automated volumetric method, using a 3D volume rendering tool, was applied to measure OV. The total orbital volume difference (TOVD), posterior orbital volume difference (POVD), and anterior orbital volume difference (AOVD) were measured as predictive factors in traumatic and intact orbits. Enophthalmos was also examined as the outcome, using a Hertel exophthalmometer. A total of 27 patients were examined in this study. The mean TOVD was 4.48 +/- 1.82 mm(3), the mean POVD was 1.91 +/- 0.31 mm(3), and the mean AOVD was 2.57 +/- 1.71 mm(3); also, the mean enophthalmos was 2.89 +/- 1.12 mm. Pearson's correlation test demonstrated a positive correlation between enophthalmos and TOVD, POVD, and AOVD (P<0.05). Based on the linear regression model, TOVD had a predictive power of 61.7% for enophthalmos. For every 1-mm(3) volume change, a 0.38-mm enophthalmos was expected (R-2, 0.617; B, 0.38; P = 0.001). TOVD, POVD, and AOVD showed strong correlations with enophthalmos. However, it seems that POVD has the greatest effects on the occurrence of posttraumatic enophthalmos.