2017-18 HSC Section 3 Green Book

walls, and 5% involved all orbital walls simultaneously. 23 Several studies have assessed the significance of frac- tures of each orbital wall. Jank et al. assessed the signif- icance of medial wall involvement and concluded that these patients had statistically significant increases in exophthalmos and diplopia at the time of initial evalua- tion. 24 However, this study included only patients eval- uated at 12 hours postinjury, which most likely biases their results secondary to swelling. Associated ocular injuries with roof fractures were studied by Fulcer and Sullivan. 25 They found that five of 21 (23.8%) patients with roof fractures had ocular injuries and another five patients had periorbital problems such as ptosis, intraor- bital foreign body, and oculomotor nerve palsy. He et al. studied floor fractures and found that 22% of 240 orbit floor fractures had associated ocular injuries, thus con- cluding that the ocular bone-buckling theory is the most likely mechanism of globe protection in these patients. 26 Stanley et al. studied lateral wall fractures and described a triad of a lateral blow-in fracture, decreased visual acu- ity, and ocular motility limitations. 27 They suggested that early surgical management could correct this triad in cases such as this. Many studies have described the incidence of ocular injury with concomitant maxillofacial trauma. Read and Sires studied the relationship between anatomic location and ocular injury. 28 They published results showing that ocular injury is statistically associated with orbit apex fractures, lateral wall fractures, and Lefort III fractures. Several publications have studied the location of maxillo- facial fractures with the incidence of ocular injury or blindness. Shere et al. compared the incidence of eye injuries in U.S. Army soldiers presenting with ZMC frac- tures (3,599 soldiers) or orbital floor blowout fractures (1,141 soldiers). 29 In their study, blowout fractures were significantly more likely to sustain concomitant eye injury than ZMC fractures (29.8% and 7.6%, respec- tively). Barry et al. described a 20% incidence of ocular injury and 2% incidence of vision loss in patients with ZMC fractures. 30 Jamal et al. demonstrated retinal hem- orrhage (4%) and retinal detachment (2%) as the most likely ocular injury associated with ZMC fractures. 31 This study included only subjects requiring ZMC frac- ture repair, and the selection bias for more severe inju- ries explains their different ocular injury patterns. In this current study, isolated lateral orbit fractures (66.7%) were the most common anatomic location on CT imaging to be associated with ocular injury, followed by isolated medial wall fractures (42.9%). Surprisingly, iso- lated multiwall injuries had a much lower association with ocular injury and most likely can be explained by a disbursement of energy by the eye socket protecting the globe. Orbit fractures associated with other facial frac- tures similarly demonstrated a lower association of con- comitant eye injury and possibly a similar phenomenon of globe protection when multiple facial bones absorb maxillofacial trauma. Neither orbit fractures isolated to a specific wall nor those in conjunction with other facial fractures were statistically associated with ocular injury in this study.

The location and depth of the fracture within the orbit may also predict the relative risk of ocular injury. In general, fractures of the anterior orbit involve less energy than fractures of the posterior orbit. Lauer et al. developed a classification system based on the fractures anatomic location relative to the infraorbital nerve. 32 They described three types of fractures: 1) fractures medial to the infraorbital nerve, 2) floor fractures lateral to the infraorbital nerve, and 3) fractures on both sides of the infraorbital nerve. Unfortunately, no clinical rele- vance was reported with this classification system. Tsai et al. established two groups of orbit fractures: those that involve the anterior two-thirds of the orbit and frac- tures involving the posterior third of the orbit. 33 They found a significant relationship between visual acuity improvement and anterior fractures, and that posterior orbit fractures are associated with a worse visual out- come. These findings are supported by the current study because it demonstrates a statistical significance of asso- ciated ocular injury when the orbit fracture extends to the posterior third of the orbit. This intuitively makes sense because posterior orbit injuries indicate the exer- tion of high energy forces and an anatomic approxima- tion to the entire globe, subjecting it to injury. Several studies have looked at the specific ocular injury leading to vision loss in patients with concomitant facial fractures. Dancey et al. determined that vision loss most commonly results from traumatic optic nerve injury when an associated facial fracture was present. 34 In contrast, Ansari 35 reported retrobulbar hemorrhage, and Ugboko et al. 4 reported globe rupture as the leading cause of vision loss in their studies involving motor vehi- cle accident and penetrating trauma, respectively. Table I demonstrates that a wide variety of ocular injuries were identified, and every group studied had an associated globe injury in at least one patient. Many of these ocular injuries can only be documented by a trained ophthalmologist. A major take-home message of this article is that all maxillofacial trauma patients with an orbit fracture require an ophthalmologic evaluation. This dataset does not have the power to investigate which ocular injuries are most common with specific mechanisms, physical exams, or radiographic patterns of injury. However, this study does demonstrate that cer- tain orbit fracture patients are statistically more likely to have a globe injury, and thus the suspicion of injury should be highest in these individuals. There are several limitations of this study. First, this study is a retrospective review and does not demon- strate prospective data. As such, preinjury ophthalmo- logic evaluations are not present for any of the patients included in this study. Therefore, it is possible that ocu- lar injuries described in this study existed prior to the subject’s maxillofacial trauma and orbit fracture. Addi- tionally, the power of this study does not allow for the assessment of specific ocular injuries with either mecha- nism of injury, physical exam findings, or radiographic imaging. The concept of this study is to identify high- risk maxillofacial trauma patients who absolutely require ophthalmologic consultation prior to surgery. By identifying patients as high risk, it is hoped that long-

Laryngoscope 126: February 2016

Andrews et al.: Ocular Injury and Orbit Fractures

78