2017-18 HSC Section 3 Green Book

facial swelling, medications, sedation, and patient monitor- ing of neurologic injury. Thus, identification of patients at high risk of ocular injury by maxillofacial trauma care pro- viders is essential but often insufficient. The objective of this study is to identify patients with orbit fractures who are at high risk for concomitant ocular injury and possible vision loss. The specific aim of this project is to stratify orbit fractures based on basic information available to most, if not all, maxillofacial care providers. This basic information consists of mecha- nism of injury obtained during a routine patient history, physical exam findings, and radiographic findings. The hypothesis of this study is that history, physical exam findings, and radiographic imaging can be used to iden- tify subgroups of patients at high risk for ocular injury and vision loss. More specifically, it is hypothesized that the likelihood of concomitant ocular injury can be deter- mined by: 1) the mechanism of injury determined from the patient history; 2) physical exam findings such as visual acuity, extraocular movements, afferent pupillary defect, and chemosis 6 subconjunctival hemorrhage; and 3) radiographic fracture patterns categorized by ana- tomic location and depth of injury. By using this infor- mation and identifying high risk individuals early, patient management can be tailored to prevent further ocular injury and aid in vision preservation. MATERIALS AND METHODS After institutional review board approval (13059) was obtained, a retrospective clinical chart review was performed. Patients with maxillofacial trauma were identified by reviewing the trauma registry at a tertiary academic medical center. All subjects between January 1, 2007, and December 31, 2012, who were diagnosed with an orbital fracture were included. Inclu- sion criteria for this study included maxillofacial trauma with an associated orbit fracture, comprehensive ophthalmologic examination, and computed tomography (CT) radiographic imaging. Subjects were excluded from this study when this information was not available. History Assessment The mechanism of injury was determined from the docu- mented patient history and was categorized into five groups. These groups included: motor vehicle accident (MVA), blunt trauma, penetrating trauma, fall, and unknown. The unknown group consisted of a small number of patients (n 5 5) who had an undocumented etiology in their medical records. Physical Examination Assessment Clinical notes and ophthalmologic records were reviewed to assess key physical exam findings. Four key physical exam findings were utilized in this study. These included: 1) extraocu- lar movements, 2) afferent pupillary defect, 3) chemosis 6 sub- conjunctival hemorrhage, and 4) decreased visual acuity. Visual acuity was based on a comparison with the noninjured eye in unilateral injuries and was consider normal if it was 20/40 or better in bilateral patients. Physical exam findings were meas- ured independently of each other. Therefore, a single subject could present with a single or multiple abnormal physical exam findings.

Radiographic Assessment Maxillofacial CT scans were used to assess radiographic fracture patterns for all subjects. When possible, CT images in the axial, coronal, and sagittal plane were reviewed, as well as three-dimensional computer-generated reconstructions. Two groupings of orbital fractures were utilized: 1) anatomic orbit fracture patterns and associated facial fractures, and 2) depth of eye socket involvement. The first grouping assessed the anatomic orbit fracture pattern. In this grouping, orbit fractures were classified as either isolated single-wall fractures (floor, medial wall, lateral wall, and roof), multiwall fractures isolated to the orbit alone, and orbit fractures associated with other facial fractures. These fractures included nasal or naso-orbital-ethmoid (NOE) frac- tures, zygomaticomaxillary complex (ZMC) fractures, frontal bone fractures, and/or multiple panfacial bone fractures. The second orbit fracture grouping was based on depth of eye socket involvement. This classification method is most read- ily visualized on sagittal CT images; however, all planes were utilized for fracture identification. Type 1 (superficial type) frac- tures are isolated to the orbital rim and anterior maxilla; type 2 (intermediate type) fractures extend from the anterior to the posterior globe; and type 3 (posterior type) fractures are located posterior to the globe. Ocular Injury Assessment All clinical evaluations and ophthalmologic records were reviewed. All subjects underwent a comprehensive eye examina- tion by an ophthalmologist. Ocular injury was defined as any injury determined to be unrelated to preexisting conditions and those that threatened or caused vision loss. Four groups of ocular or periocular injury were established, including anterior segment injury, a posterior segment injury, globe rupture, and retrobulbar hematoma. Anterior segment injuries included those involving structures such as the conjunctiva, sclera, cornea, anterior cham- ber, iris, ciliary body, and lens. Posterior segment injuries involved the retina, macula, choroid, fovea, optic nerve, and vitreous humor. For the purpose of this study, periocular injury such as retrobulbar hematoma was reported as an ocular injury, although technically it is not one. Statistical Analysis Statistics were performed on mechanism of injury, physi- cal exam findings, and CT radiographic imaging. A chi-square analysis and a Fisher exact test were used to assess the associa- tion of these variables with ocular injury. A P value of 0.05 was used to determine statistical significance. RESULTS Three hundred and ninety-six subjects who sus- tained maxillofacial trauma during the study period were identified through the institutional trauma registry. Two hundred and seventy-nine were identified to have orbit fractures and met inclusion criteria for this study. There were 209 males (74.9%) and 70 females (25.1%) in the study. The average age was 42.1 years, and the range was 8 to 95 years of age. One hundred thirty-six of the 279 subjects (48.7%) required surgical repair of their orbit fracture 6 other associated facial fractures. Seventy-seven of the 279 subjects (27.6%) were iden- tified to have an ocular injury that threatened visual acu- ity or caused vision loss in this study (Table I). Ocular

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