Association between pre- and intraorbital soft tissue volumes and the risk of orbital blowout fractures using CT-based volumetric measurements.

Orbital blowout fractures result from trauma which breaks the bony orbital wall while sparing the rim. Previous research into fracture mechanism has focused on bony anatomy. This study evaluates the role of preorbital and intraorbital soft tissue volume in fracture risk. A retrospective case-control study was conducted on 51 cases of adults with unilateral orbital blowout fracture, matched to 51 controls who had experienced orbital trauma by comparable mechanisms without sustaining a fracture. Axial Computed Tomography (CT) images with orbital fine cuts were assessed on a 3D post-processing workstation to measure the volume of the pre- and intraorbital soft tissues, then compared between the two groups using Mann-Whitney U analysis. In the case group, there were 40 males (78%), injured by assault (66%), fall (12%), motor vehicle collision (10%), or other cause (12%). The control group included 33 males (65%), injured by assault (55%), fall (22%), motor vehicle (4%), or other cause (20%). There was no significant difference in mechanism rates between case and control groups. Median preorbital volumes were 12.5 cm3 in the case group and14.1 cm3 in controls (p = 0.02). Median intraorbital volumes were 24.4 cm3 in the case group and 25.9 cm3 in controls (p = 0.003). CT volumetric analysis shows that patients who sustained blowout fractures have lower preorbital and intraorbital soft tissue volume than those who did not fracture. This underscores the significant role that soft tissues play in dissipating impact forces, both anterior to the orbital rim and within the orbit itself.

Traumatic Ptosis: Evaluation of Etiology, Management and Prognosis.

INTRODUCTION: To investigate whether a systematic approach to subgrouping traumatic ptosis according to etiology can allow for better tailoring of prognosis and treatment. METHODS: Retrospective chart review of patients with trauma-related blepharoptosis managed by Oculoplastic surgery specialists at an academic medical center from January 1995 to November 2015. Injury mechanism, eyelid position and function, interventions, and outcomes were reviewed. RESULTS: Of 648 patients treated for blepharoptosis, 55 (8.5%) were traumatic. Careful review revealed 4 subcategories of traumatic ptosis cases: aponeurotic (n = 16), myogenic (n = 18), neurogenic (n = 7), and mechanical (n = 14). Margin reflex distance (MRD1) at presentation was significantly worse for the myogenic subtype (-0.59 mm, SD ±2.09, P = 0.046). The aponeurotic subtype had the best average levator function at presentation (14.29 mm, SD ±2.05), while myogenic had the worst (8.41 mm, SD ±4.94) (P = 0.004). Thirty-five (63.6%) patients were managed surgically. Final MRD1 was significantly different for each subtype (P = 0.163), with aponeurotic 2.63 mm (SD ±1.01), myogenic 1.29 mm (SD ±2.24), neurogenic 1.79 mm (SD ±2.48), and mechanical 2.31 mm (SD ±1.18). There was a significant increase in MRD1 from presentation to final follow up across all groups (P < 0.05). CONCLUSION: Traumatic ptosis is heterogenous. Systematically evaluating traumatic ptosis cases by trauma mechanism can guide decisions about prognosis and management. Two-thirds of cases were treated surgically, with most patients responding well to conjunctiva-Müller resection or external levator advancement. While all subgroups demonstrated improvement in MRD1 at final follow up, aponeurotic cases had the best prognosis, while myogenic fared the worst and required the longest for maximal recovery.