The pressure will be transmitted to orbital tissues and then to the globe, resulting in an increase in intraocular pressure which may cause visual loss when the nutrient vessels supplying the optic nerve are compressed. Stage IV
Stage IV orbital emphysema develops when the intraorbital air mass  results in an intraocular pressure of more than 60 to 70 mmHg. The significantly elevated intraocular pressure will lead to central retinal artery occlusion, which may result in permanent and irreversible damage to the retina. Clinical Diagnosis
The diagnosis of orbital emphysema is usually made by physical examination of the eyelids, and, or by computer tomography (CT). Physical examination
Physical examination of the eyelid can be done by the palpation for the pathognomonic cracking, crepitation, and tense tissue on the upper and lower eyelids. The findings of the examination are supported with the medical history of the patient and confirmed with orbital CT.

Computed tomography (CT)
Computed tomography is effective and sensitive in the diagnosis of orbital emphysema, as it can confirm the anatomical location and size of air, bony defects, indentation of the eyeball, and the condition of the optic nerve, as well as the presence of any extraocular muscle entrapment and herniation of preorbital fat into the sinus cavities. The location of the orbital emphysema is present near the site of the fracture. The scans are usually taken along the transverse plane. Transverse images allow the evaluation of fractures in medial and lateral orbital walls.
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.