What Computed Tomography Findings Are Predictive of Posttraumatic Enophthalmos in Orbital Fractures?

BACKGROUND: Enophthalmos is a surgical indication for orbital fracture repair. However, guidelines to predict enophthalmos in orbital fractures are ambiguous. The authors systematically reviewed the existing literature on using computed tomographic findings to establish objective metrics to predict enophthalmos in asymptomatic patients during initial trauma work-up. METHODS: Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. PubMed and Embase were used to identify studies of interest. The Quality in Prognosis Studies tool was used for risk of bias assessment. Random-effects model meta-analyses of orbital volume change and fracture area values were completed. Regression analyses were performed to determine thresholds that predicted 2 mm of enophthalmos. RESULTS: Of the initial 2236 abstracts, 36 met inclusion criteria. Thirty retrospective studies evaluated a total of 2851 patients, and 6 prospective studies evaluated 211 patients. All 36 studies had predominantly low risk of bias. Predictors of enophthalmos assessed were orbital volume change (21 articles), fracture surface area (13 articles), inferior rectus muscle displacements (7 articles), and fracture location (4 articles). Studies reporting on orbital volume change offered values ranging from 0.69 to 4.26 cm 3 . Fracture area predictor values ranged from 1.50 to 3.38 cm 2 . Meta-analyses confirmed the validity of both predictors. Pooled regression analyses demonstrated that 3.33 cm 3 of orbital volume increase or fracture area of 3.12 cm 2 were predictors of 2 mm of enophthalmos. CONCLUSIONS: Both orbital volume change and fracture area measured on computed tomographic scan are good predictors of late posttraumatic enophthalmos. Pooled data indicate that 3.12 cm 2 of fracture area or 3.33 cm 3 of orbital volume increase is predictive of enophthalmos.