Prognostic CT findings of diplopia after surgical repair of pure orbital blowout fractureā
Introduction
Orbital fractures are a common component of facial trauma. Orbital blowout fracture (BOF), a subtype of orbital fracture, refers to a fracture involving only the orbital inferior and/or medial wall, with an intact orbital rim. The fracture typically occurs after blunt trauma to the orbit. Sequelae of BOF include enophthalmos, diplopia, infraorbital nerve anesthesia, disfiguring facial contours, and tearing from obstruction of the nasolacrimal duct (Harris etĀ al., 2000, Burnstine, 2002). The goal with orbital wall reconstruction is to improve visual function and orbital appearance. However, even after proper surgical management, ocular motility disturbance and diplopia persists in 9ā30% of patients (Cope etĀ al., 1999; Harris etĀ al., 2000, Hosal and Beatty, 2002, Gosau etĀ al., 2011). Diplopia results from deformity of the orbit (causing positional changes of the muscles), adhesive impingement of the content (disturbing ocular excursion), or impairment of the contracting muscle (resulting from neurogenic or myogenic palsy) (Yano etĀ al., 2010).
Many prognostic factors have been implicated in diplopia (Harley, 1975, Hawes and Dortzbach, 1983, Gilbard etĀ al., 1985, Lyon and Newman, 1989, Biesman etĀ al., 1996, Folkestad and Westin, 1999, Okinaka etĀ al., 1999; Harris etĀ al., 2000, Hosal and Beatty, 2002, Furuta etĀ al., 2006, Jin etĀ al., 2007, Tahiri etĀ al., 2010, Matsunaga etĀ al., 2011, Hwang etĀ al., 2012, Neinstein etĀ al., 2012). Several studies have analyzed CT findings associated with diplopia after surgical management (Harris etĀ al., 2000, Furuta etĀ al., 2006, Jin etĀ al., 2007, Tahiri etĀ al., 2010, Matsunaga etĀ al., 2011). Furuta etĀ al. (2006) reported that fracture type and number of extraocular muscle (EOM) contact points with the fracture edge on multiplanar reconstruction CT images are important prognostic indicators of ocular motility. Harris etĀ al. classified blowout fractures based on soft tissue distortion relative to bone fragment configuration and noted that fracture type influences postoperative motility (Harris etĀ al., 2000). Jin etĀ al. (2007) demonstrated that EOM swelling on CT is associated with a higher incidence of residual diplopia after surgery and seems to be a reliable prognostic factor of postoperative diplopia. Matsunaga etĀ al. (2011) also reported that diplopia and impairment of eye movement after surgery tends to remain in the patients with EOM swelling on preoperative CT images. Tahiri etĀ al. (2010) reported that initial EOM injury leading to EOM swelling and preoperative diplopia seems to be the origin of diplopia after surgical repair of pure BOF. However, these studies evaluated the relationship between only one or two CT findings and postoperative diplopia. Therefore, the aim of this study was to evaluate various CT findings and determine possible prognostic factors leading to new or persistent diplopia after surgical repair of pure BOF.
Section snippets
Patients
The institutional review board approved this study, and the informed consent requirement was waived for this retrospective review.
Between January 2007 and October 2014, a search of the electronic database of our hospital revealed 488 patients who underwent surgical repair for orbital fractures. Among them, 306 patients were excluded from the study group using these exclusion criteria: (1) postoperative follow-up period shorter than six months (nĀ =Ā 217), (2) revision surgery (nĀ =Ā 40), (3)
Results
The patients in this study included 134 (74.0%) males and 47 (26.0%) females, aged 4ā71 years (mean, 27.5 years). Most of the patients (164, 90.6%) were injured through a low-velocity mechanism. Before surgery, 138 patients (76.2%) complained of diplopia, 38 patients (21.0%) presented with enophthalmos, and 74 patients (40.9%) had abnormality of ocular motility. The mean interval between trauma and surgery was 14.8 days (range; 1ā151) in all enrolled patients, 17.0 days (range; 2ā151) in
Discussion
Diplopia is an indication for repair surgery after BOF but remains a common sequela of BOF even after proper surgical management. Diplopia results from injury to the anatomical structure of the orbit including EOMs and/or functional impairment of EOM movement. The rectus EOMs originate in the annulus of Zinn, which is a common fibrous ring surrounding the optic nerve in the orbital apex. The rectus EOMs run anteriorly through loose, areolar lobules of orbital fat without mechanical constraint,
Conclusions
This study provides prognostic CT findings of postoperative diplopia in patients who underwent surgical repair for pure BOF. Patients who had EOM tenting or deformity on CT scan were more likely to have postoperative diplopia. Injury and fibrosis of the connective tissue framework and subsequent muscular adhesions may play a role in diplopia.
Funding
None.
Conflict of interest
None.
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2019, Facial Trauma Surgery: From Primary Repair to ReconstructionFactors Influencing Postsurgical Diplopia in Orbital Floor Fractures and Prevalence of Other Complications in a Series of Cases
2018, Journal of Oral and Maxillofacial SurgeryCitation Excerpt :However, according to these authors, this could be explained by the risk of muscle entrapment after a long period of soft tissue herniation, which results in a greater volume of herniated tissue. According to Jung et al,27 only muscle herniation is significant (P ā¤ .05) regarding postoperative diplopia; however, the volume of herniated tissue is not significant with respect to postoperative diplopia. We did not measure the orbital volume in this study; however, significant differences between muscle herniation and postsurgical diplopia were found in the bivariate analysis (P = .007) but not in the multivariate analysis.
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2018, Archivos de la Sociedad Espanola de OftalmologiaComparison of clinicoradiological findings between patients with recovering diplopia and those with residual diplopia after surgery for pure orbital blowout fracture
2018, Journal of Cranio-Maxillofacial SurgeryCitation Excerpt :This situation was distinct from the presence of general contour changes, which were defined as swelling or displacement of the EOM. Other detailed definitions of CT findings were used as published previously (Jung et al., 2016). We subdivided patients into five age subgroups: 0ā12 years, 13ā24 years, 25ā36 years, 37ā48 years, and older than 48 years (n = 16, 58, 47, 33, and 16, respectively) to analyze diplopia recovery rate.
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The authors declared that they did not receive any grant from others.