CT-Based Morphological Analysis of Isolated Inferior and Medial Blow-out Orbital Fractures in Korean Adults.

PURPOSE: To evaluate morphologic differences in isolated inferior medial orbital wall fractures (OWF) based on computed tomography scans. METHODS: This was a retrospective observational case study of 22 patients with an isolated inferior OWF and 32 patients with an isolated medial fracture between January 2008 and August 2010. We analyzed patient demographics and bony radiologic characteristics on CT scans, including the length and height of the lamina papyracea, the number of ethmoid air cell septa, the length of the anterior and posterior border of the orbital floor, the thickness of the orbital floor maxillary bone, and the axial length of the eyeball. RESULTS: There were no significant differences in sex, laterality, or concomitant intraocular injury between the two groups. The anteroposterior length (p = 0.391), the number of ethmoid septa (p = 0.869), and the thickness of the orbital floor (p = 0.419) did not differ significantly. The anterior (p < 0.001) or posterior (p = 0.014) height of the lamina papyracea, the lamina papyracea area (p < 0.001), and the lamina papyracea area/ethmoid air cell septa (p = 0.024) were significantly higher in the medial OWF group, while the anterior (p = 0.026) or posterior (p < 0.001) border length of the orbital floor and the axial length (p = 0.047) and volume (p = 0.034) of the eyeball were longer and smaller, respectively, in the inferior OWF group. CONCLUSIONS: Patients with a longer anterior or posterior border of the orbital floor, a shorter axial length, and a smaller eyeball volume are more likely to incur an isolated inferior OWF than an isolated medial OWF.

Orbital blowout fracture location in Japanese and Chinese patients.

PURPOSE: To characterize the location of orbital blowout fractures in Asian individuals. METHODS: This was a retrospective review of 470 consecutive Asian patients with orbital blowout fractures who presented to four tertiary care hospitals in Japan and China. Computed tomography (CT) characterized the location and severity of fractures involving the medial wall, the orbital floor, and/or the maxilloethmoidal strut. RESULTS: A total of 475 orbital blowout fractures were identified. More than one fracture location was involved in 19% of all cases. The medial orbital wall was the most commonly involved location, presenting in 29 cases (61%), of which 204 (43%) were isolated medial blowout fractures. The orbital floor was the second most common location involved, present in 226 cases (48%) with 150 isolated orbital floor fractures (32%), while the maxilloethmoidal strut was involved in 45 cases (9%) with 30 of those being isolated strut fractures (6%). The majority of fractures (62%) were classified as moderately severe, whilst 14% were mild, and 24% were severe. Associated nasal fractures were present in 16% of the cases. CONCLUSIONS: Orbital blowout fractures in Japanese and Chinese individuals occur most commonly in the medial wall. This is in contrast to previous reports on white individuals, who tend to sustain fractures involving the orbital floor rather than the medial wall.

Orbital blowout fractures and race.

PURPOSE: To examine the type of orbital blowout fracture and its variation with race. DESIGN: Retrospective review of computed tomography (CT) scans and demography in an unselected cohort of patients with orbital blowout fractures. PARTICIPANTS: Patients with a high-resolution CT scan of adequate quality for analysis who presented with an orbital blowout fracture to the Orbital Clinic at Moorfields Eye Hospital. Patients with fractures involving the orbital rim or the cranium, or with penetrating injuries of the globe or orbit, were omitted from the study. METHODS: Demographic and ethnic information was collected for each patient, and the orbital scans were reviewed by a single observer. On the basis of coronal and axial imaging, a fracture was classified as affecting up to 4 areas: the floor lateral to the infraorbital canal (area 1, "A1"), the floor medial to the canal ("A2"), the maxillo-ethmoidal strut ("inferomedial" strut, "A3"), and the medial wall blowout fracture ("A4"); with fractures involving the inferomedial strut, it was noted whether there was displacement or rotation of the strut. Ethnic origin was classified as Caucasian, Afro-Caribbean, or Asian (Oriental or Indian). MAIN OUTCOME MEASURES: The proportion of different walls involved in orbital blowout fractures within 3 ethnic groups. RESULTS: A total of 152 patients (125 men, 82%) had imaging adequate for analysis; 103 (68%) were Caucasian, 19 (12%) were Afro-Caribbean, and 30 (20%) were Asian. Caucasians most commonly had floor fractures (A1 or A2 in 56 orbits, 54%) compared with 10 of 103 purely medial fractures (A4, 10%); in contrast, medial fractures were the most common type in Afro-Caribbean patients (7/19 cases, 37%), and purely floor fractures occurred in only 2 cases (10%) (P<0.005). Asian patients had results similar to those for Caucasian patients, with isolated floor fractures being the most common (14/30 cases, 47%). CONCLUSIONS: Most blowout fractures involve the orbital floor in Caucasian and Asians, whereas in Afro-Caribbeans the most common site for fracture is the medial wall. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Prediction of enophthalmos by computer-based volume measurement of orbital fractures in a Korean population.

PURPOSE: To estimate posttraumatic enophthalmos using computer-based volume measurement of the orbital fracture to provide information on surgical guidelines. METHODS: The fracture volume of orbital wall fractures in 35 patients who did not undergo surgery was measured using a Rapidia work station system. Hertel ophthalmometry, diplopia, and ocular motility were investigated. The fracture volume measurements relative to the intact contralateral orbit were correlated with enophthalmos, diplopia, and ocular motility. Patients were examined at the initial visit, then at 1 week, 1 month, and 3 months. RESULTS: There was a correlation between the fracture volume and enophthalmos. Late enophthalmos increased in size in proportion to the volume of the fractured site. The predicted orbital fracture volume with an enophthalmos measurement of 2 mm or more was 2.30 ml. CONCLUSIONS: Computer-based measurements of orbital fracture volume can be used to predict overall enophthalmos and provide useful information to surgeons.