Orbital blow out fracture : to operate or not to operate – that is the question

Abstract: When the eye socket is exposed to severe blunt trauma the pressure in the socket increases. As a protection mechanism to prevent the eye from disruption, the thin bony walls surrounding the eye fracture. Such a fracture is called Blow Out Fracture (BOF). It is well known that a significant BOF needs surgical treatment otherwise it may lead to double vision and aesthetic deformities such as sunken eye. Furthermore, small BOF are not considered to need any surgical treatment and will heal without any remaining symptoms. It is highly important to differentiate which patients need to be operated on or which do not. This has been the subject of several studies over the past few decades. The overall aim of this thesis has been to identify which patients with BOF need an operation and which do not require an operation to prevent functional and aesthetic disorders. In paper I we found that the amount of displaced orbital tissue (herniation) and the relative change in the orbital volume due to trauma may be insufficient predictors to use when differentiating if a patient needs surgical or non-surgical treatment. In Paper II we concluded that there is a clear agreement that surgery within 24h is needed when motility of the eye is hindered. Regarding the management of the remaining patients with BOF, there are considerable differences in opinion between the surgeons, specialties and countries, despite existing recommendations. In paper III we found that in the case of entrapment with restriction of eye motility, there is a need for surgical treatment performed by an experienced surgeon as soon as possible, but not necessarily within 24h. Furthermore, we found that double vision due to eye motility restriction caused by impingement is not an ophthalmologic emergency and surgery is recommended if the diplopia and eye motility is not improved over time. We also found that the surgical reduction of all impinged or entrapped tissue is at least as important as surgical timing for the outcome. In paper IV-V we performed prospective cohort and controlled randomized studies on patients with BOF. We found a significant correlation between CT scan findings on presentation to aesthetic outcome, namely patients who developed cosmetic problems compared to those patients who did not develop any cosmetic problems. We could therefore conclude that BOF patients with the following findings have a substantial risk for the development of cosmetic deformities and surgical treatment needs to be considered: • Isolated inferior wall fracture with a herniation < 1.0 ml and a fracture area ≥ 2.3 cm2. • Isolated inferior wall fracture with a herniation ≥ 1.0 ml and a fracture distance from inferior orbital rim to the posterior edge of the fracture ≥ 3.0 cm. • Inferomedial fracture with a herniation ≥ 0.9 ml. We also found that double vision in BOF, without eye motility limitation, is due to edema and it is not an indication for surgery. The statement that, sunken eye (enophthalmus) will lead to double vision could not be supported by our data. On the contrary, none of the patients with late enophthalmus had double vision and none of patients with double vision had enophthalmus. Furthermore, we found that delayed correction of BOF appears to have the same aesthetic outcome as early corrections, if the surgical correction is performed immediately after the aesthetic deformities are discovered. Therefore, BOF patients require a close follow-up of, as a suggestion 1 and 3 months post-injury. In this project, we have provided an algorithm based on available evidence to predict which patients with BOF benefit from surgical vs non-surgical treatment. In summary, when deciding whether to operate or not on a BOF, it is important to recognize that a surgical indication upon functional impairment is limited to muscle motility restriction due to entrapment or impingement. Other functional impairment is generally benign and will resolve over time. Regarding the decision making around surgical treatment due to aesthetic deformities, patient´s involvement is crucial since the patient´s experience of the importance of facial asymmetry is individual and this may differ from the surgeons´ opinion.