Orbital emphysema (/ˈɔː(r)bɪt(ə)l ˌemfɪˈsiːmə/, also known as pneumo-orbit) is a medical condition that refers to the trapping of air within the loose subcutaneous around the orbit that is generally characterized by sudden onset swelling and bruising at the impacted eye, with or without deterioration of vision, which the severity depends on the density of air trapped under the orbital soft tissue spaces.It is most commonly result from forceful sneezing, nose blowing, or coughing among patients with a history of periorbital trauma or orbital fractures that happened several hours-days in advance. Rare occasions have also been reported in relation to individuals with no traumatic past events that include: infection, esophageal rupture, postoperative complications, pulmonary barotrauma, with the same predisposing factors (sneezing, nose blowing, or coughing). A four-stage system of orbital emphysema was developed for severity classification. Clinical diagnosis can be made based on a combination of medical history, physical examination, and computed tomography. There are three kinds of orbital emphysema including palpebral emphysema, true orbital emphysema, and orbitopalpebral emphysema.Orbital emphysema on its own is a mild and self-limiting disease, and usually requires no treatment. If related visual symptoms or other acute orbital compression symptoms are present, lateral canthotomy or cantholysis, orbital decompression by needle aspiration, and bone decompression may be required to relieve orbital pressure and preserve vision. Cause
Trauma
Blunt trauma caused by a direct blow at the orbital is the major leading cause of orbital emphysema.
By reformatting these transverse images or taking coronal images, the examination of orbital floor and roof is permitted. Helical scanning is preferred as it has a lower imaging time and radiation dose comparing to conventional scanning, especially when reforming transverse helical scans into coronal images. The staging of orbital emphysema can then be determined with visual acuity examination and ophthalmoscopy. A disadvantage of using a CT scan is that when detecting air after orbital trauma, the presence of a wooden foreign object can give a false positive result of orbital emphysema. The wooden object can mimic the presence of orbital emphysema. Therefore, patients’ medical history is crucial in making the correct diagnosis. Other tests
Conventional radiography is commonly employed for imaging orbital injuries and identifying orbital fractures. It can be used to diagnose orbital emphysema because it shows the presence of air in the orbit best while the patient is standing upright. Skull films of posterior-anterior, lateral projections, and orbital rim views are recommended to show fractures in orbital rims and walls. However, CT scan is better than conventional radiography in the diagnosis of the condition, as it has a lower high false-negative rate and non-diagnostic rate.Orbital emphysema can also be diagnosed by magnetic resonance imaging (MRI). Although MRI has a low sensitivity for detecting orbital fractures, it can be used to evaluate rectus muscle pathology, optic nerve pathology, and brain pathology, as well as vascular injury. Treatment
Orbital emphysema on its own is a mild and self-limiting disease.