Indications for Lateral Canthotomy Orbital compartment syndrome (OCS), an ophthalmologic emergency, which manifests with rapid, progressive vision loss, increased intraocular pressure, decreased extraocular motility, and pain in a patient with recent eye / orbital trauma or surgery Blunt facial trauma (see Eye Contusions and Lacerations) may cause retrobulbar hematoma or severe edema surrounding the eyeball, either of which can increase intraorbital pressure.