Abstract
Purpose: :
To investigate the ability to clinically diagnose ipsilateral retrobulbar hemorrhage in the setting of acute orbital fracture (AOF) by using computed tomography (CT) as a gold standard in comparison to bedside physical examination techniques
Methods: :
We conducted a retrospective review of 306 consecutive cases of acute orbital fracture that presented to Bellevue Hospital from July 2007 to May 2010. Of these, 28 cases of concurrent retrobulbar hemorrhage as evidenced on CT were noted and set aside for subgroup analysis. Medical records were screened for demographic features, associated history, ocular/systemic co-morbidities, and radiographic findings. An IRB exemption was obtained from the Bellevue Research Committee.
Results: :
Mean age in the study cohort was 48.4 years (Range: 27 - 90) with equal distribution of males and females. Via radiographic review, 21.4% of patients had fractures of only the orbital floor while 7.1% of patients had only either a fracture of the orbital roof, medial wall, or lateral wall, respectively; the remaining 16 patients had fractures of multiple orbital walls. Mean intraocular pressure (IOP) by tonopen in our patients was 21.6 mmHg (Range: 11 - 51). By using CT imaging as the gold standard for the diagnosis of retrobulbar hemorrhage in comparsion to clinical signs that may indicate the finding, we were able to retrospectively calculate the sensitivity, specificity, positive predictive value (PPV), and positive likelihood ratio (LR+) for bedside accurate diagnosis utilizing asymmetric exophthalmometry, increased IOP, and/or a combination of the two. Asymmetric exophthalmometry had a 37.5% sensitivity, 92.4% specificity, 21.4% PPV, and 4.9% LR+, while IOP>30 had a 16.7% sensitivity, 91.9% specificity, 21.4% PPV, and 2.1% LR+. When combined, beside Hertel’s measurements and IOP>30 had 40% sensitivity, 91.8% specificity, 21.4% PPV, and 4.9% LR+ in predicting retrobulbar hemorrhage that was later confirmed on CT.
Conclusions: :
Acute orbital fracture with concurrent retrobulbar hemorrhage requires immediate attention to prevent visual compromise. In our study, fractures of multiple orbital walls correlated most with the presence of retrobulbar hemorrhage, rather than fracture of a single wall. Although well-described, the diagnosis of retrobulbar hemorrhage in the setting of AOF cannot always be made on elevated IOP and/or orbital asymmetry, alone. While these examination techniques may raise suspicion for retrobulbar hemorrhage, CT remains the gold standard for detection and definitive treatment.
Keywords: trauma • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • clinical (human) or epidemiologic studies: systems/equipment/techniques