Purpose
There is continued ambiguity surrounding precise prediction of what degree of orbital floor fracture necessitates surgical repair. Our study aims to shed light on this topic further by assessing orbital volume as a predictor for enophthalmos in radiographic measurements.
Methods
Twenty maxillofacial CT scans of patients with unilateral blowout fractures and enophthalmos following blunt trauma are included in our study. Orbital volume was defined as all content posterior to the orbital rim and up to, but not including the optic canal. The degree of enophthalmos was measured from the native intraocular lens perpendicular to an imaginary line connecting the edges of the orbital rim. All measurements were done in the axial scan of both orbits using a post-processing program (ADW workstation, General Electric, Fairfield, CT) by the manual tracing method. In addition, the area of the orbital floor fracture was manually measured as well as the dimensions of herniation through the defect. Finally, inter-user reliability and the volume ratio between each patient’s orbits were also assessed.
Results
Pearson correlation for traumatic orbital volume and degree of enophthalmos is 0.75. The correlation between the ratio of each patient’s orbital volumes and degree of enophthalmos is 0.19. Pearson correlation for inter-user reliability for the CT-based measurements was 0.98.
Conclusions
Volume of traumatized orbits is a useful adjunct to assess degree of enophthalmos and facilitate timely surgical intervention. These data may be reproducible between users.
Keywords: 631 orbit •
549 image processing •
551 imaging/image analysis: non-clinical