View source for Medicine:Orbital emphysema

{{Infobox medical condition
| name          = Orbital emphysema
| caption       = Woman with preorbital swelling in orbital emphysema shown in [[CT scan]]s
| treatment     = No treatment for stage I and II, [[Medicine:Canthus|lateral canthotomy or cantholysis]], orbital decompression by needle aspiration, and bone decompression for stage III and IV orbital emphysema<ref name=":8" /><ref name=":7" />
| specialty     = [[Medicine:Ophthalmology|Ophthalmology]]
| causes        = [[Biology:Sneeze|sneezing]], nose blowing, or coughing in patients with trauma, postoperative complications, infections
| image         = Orbital emphysema.png
| pronounce     = /ˈɔː(r)bɪt(ə)l ˌemfɪˈsiːmə/
| duration      = 7-10 Days<ref name=":3" />
| alt           = 
| diagnosis     = Based on [[Medicine:Medical history|medical history]], [[CT scan|computer tomography]], and physical examination<ref name=":3" />
| synonym       = Pneumo-orbit
| differential  = Palpebral emphysema, true orbital emphysema, orbitopalperbal emphysema<ref name=":16" /><ref name=":3" />
| symptoms      = Swelling, [[Medicine:Bruise|bruising]], globe dystopia, [[Medicine:Diplopia|diplopia]], restrict [[Biology:Eye movement|ocular motility]], prohibit eyelid closure, loss of sensation over the upper cheek area, nausea, [[Medicine:Dizziness|dizziness]], [[Medicine:Vomiting|vomiting]], [[Medicine:Bradycardia|bradycardia]], [[Medicine:Syncope|syncope]], [[Medicine:Heart block|heart block]]<ref name=":0" /><ref name=":21">{{cite journal | vauthors = Abdesslem K, Sondes B, Wael E, Hajer T, Morched D, Fathi K, Mohamed A | title = [A case of post-traumatic severe orbital emphysema: case report and literature review] | journal = Journal Français d'Ophtalmologie | volume = 37 | issue = 10 | pages = e165–e167 | date = December 2014 | pmid = 25455546 | doi = 10.1016/j.jfo.2014.03.012 }}</ref>
| complications = Proptosis, [[Medicine:Visual impairment|visual impairment]], [[Medicine:Central retinal artery occlusion|central retinal artery occlusion]], compressive [[Medicine:Optic neuropathy|optic neuropathy]], [[Medicine:Compartment syndrome|orbital compartment syndrome]].<ref name=":16" /><ref name=":8" /><ref name=":9" />
}}
'''Orbital emphysema''' (/ˈɔː(r)bɪt(ə)l ˌemfɪˈsiːmə/, also known as pneumo-orbit<ref>{{cite journal | vauthors = Al-Shammari L, Majithia A, Adams A, Chatrath P | title = Tension pneumo-orbit treated by endoscopic, endonasal decompression: case report and literature review | journal = The Journal of Laryngology and Otology | volume = 122 | issue = 3 | pages = e8 | date = March 2008 | pmid = 18267045 | doi = 10.1017/S002221510700165X | s2cid = 35365970 }}</ref>) is a medical condition that refers to the trapping of air within the loose subcutaneous around the [[Biology:Orbit (anatomy)|orbit]] that is generally characterized by sudden onset swelling and [[Medicine:Bruise|bruising]] at the impacted eye, with or without [[Medicine:Visual impairment|deterioration of vision]], which the severity depends on the density of air trapped under the orbital soft tissue spaces.<ref name=":0" /><ref name=":22" />

It is most commonly result from forceful [[Biology:Sneeze|sneezing]], nose blowing, or coughing among patients with a history of periorbital trauma or orbital fractures that happened several hours-days in advance.<ref name=":23" /> Rare occasions have also been reported in relation to individuals with no traumatic past events that include: [[Medicine:Infection|infection]], esophageal rupture, postoperative complications, [[Medicine:Barotrauma|pulmonary barotrauma]], with the same predisposing factors ([[Biology:Sneeze|sneezing]], nose blowing, or coughing).<ref name=":10" /> A four-stage system of orbital emphysema was developed for severity classification. Clinical diagnosis can be made based on a combination of [[Medicine:Medical history|medical history]], physical examination, and [[CT scan|computed tomography]].<ref name=":3" /> There are three kinds of orbital emphysema including palpebral emphysema, true orbital emphysema, and orbitopalpebral emphysema.<ref name=":3" /><ref name=":16" />

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,<ref name=":15" /> [[Medicine:Canthus|lateral canthotomy or cantholysis]], orbital decompression by needle aspiration,<ref name=":7" /><ref name=":8" /> and bone decompression<ref name=":10" /><ref name=":3" /><ref name=":19" /><ref name=":12" /><ref name=":1" /><ref name=":9" /> 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.<ref name=":0" /><ref>{{cite journal | vauthors = Caranci F, Cicala D, Cappabianca S, Briganti F, Brunese L, Fonio P | title = Orbital fractures: role of imaging | journal = Seminars in Ultrasound, CT, and MR | volume = 33 | issue = 5 | pages = 385–391 | date = October 2012 | pmid = 22964404 | doi = 10.1053/j.sult.2012.06.007 }}</ref><ref name="The evaluation of pneumomediastinum">{{cite journal | vauthors = Dissanaike S, Shalhub S, Jurkovich GJ | title = The evaluation of pneumomediastinum in blunt trauma patients | journal = The Journal of Trauma | volume = 65 | issue = 6 | pages = 1340–1345 | date = December 2008 | pmid = 19077624 | doi = 10.1097/TA.0b013e318169cd24 }}</ref> Any object with force and/or speed, typically a ball, fist or vehicle accidents, can result in [[Biology:Orbit (anatomy)|orbital floor]] and/or [[Biology:Orbit (anatomy)|medial wall]] fractures.<ref>{{cite journal | vauthors = Ng P, Chu C, Young N, Soo M | title = Imaging of orbital floor fractures | journal = Australasian Radiology | volume = 40 | issue = 3 | pages = 264–268 | date = August 1996 | pmid = 8826732 | doi = 10.1111/j.1440-1673.1996.tb00400.x }}</ref><ref>{{cite journal | vauthors = Soyuncu S, Enver S | title = Eyelid swelling and lucency in the skull radiograph | journal = Annals of the Academy of Medicine, Singapore | volume = 38 | issue = 10 | pages = 928 | date = October 2009 | doi = 10.47102/annals-acadmedsg.V38N10p928 | pmid = 19890593 | s2cid = 40338796 | doi-access = free }}</ref><ref>{{cite journal | vauthors =  | title = [Fractures of the orbital floor] | journal = Bulletin des Sociétés d'Ophtalmologie de France | volume = 74 | issue = 1 | pages = 91–95 | date = January 1974 | pmid = 4430076 }}</ref> These disruptions permit air entry into the orbital subcutaneous from the [[Medicine:Paranasal sinuses|sinus]], with a [[Engineering:Check valve|one-way check valve]] mechanism that forbids the air from exiting.<ref>{{cite journal | vauthors = Bars N, Atlay Y, Tülay E, Tanju G | title = Extensive subcutaneous emphysema and pneumomediastinum associated with blowout fracture of the medial orbital wall | journal = The Journal of Trauma | volume = 64 | issue = 5 | pages = 1366–1369 | date = May 2008 | pmid = 17514044 | doi = 10.1097/01.ta.0000235507.60878.3d }}</ref><ref>{{cite journal | vauthors = Chouliaras K, Bench E, Talving P, Strumwasser A, Benjamin E, Lam L, Inaba K, Demetriades D | display-authors = 6 | title = Pneumomediastinum following blunt trauma: Worth an exhaustive workup? | journal = The Journal of Trauma and Acute Care Surgery | volume = 79 | issue = 2 | pages = 188–193 | date = August 2015 | pmid = 26218684 | doi = 10.1097/TA.0000000000000714 | s2cid = 21832402 }}</ref> Victims are often found in sport-related concussion, automobile vehicle accidents, or snowboarding accidents.

Traumatic injuries do not cause onset swelling unless there is a forceful injection of air from vigorous [[Biology:Sneeze|sneezing]], nose-blowing, or coughing.<ref name=":23">{{cite journal | vauthors = Glazer ES, Meyerson SL | title = Delayed presentation and treatment of tracheobronchial injuries due to blunt trauma | journal = Journal of Surgical Education | volume = 65 | issue = 4 | pages = 302–308 | date = 1 July 2008 | pmid = 18707665 | doi = 10.1016/j.jsurg.2008.06.006 }}</ref> These generate an acute increase in intraorbital pressure, compromising the intraorbital neurovascular structures, which subsequently trigger the development of orbital emphysema.<ref name="The evaluation of pneumomediastinum"/><ref name=":2" /><ref>{{cite journal | vauthors = Olmstead D, Gelfand G, Anderson I, Kortbeek JB | title = A Case Report of Acute Airway Compromise due to Subcutaneous Emphysema | journal = Case Reports in Medicine | volume = 2018 | pages = 3103061 | date = 2018 | pmid = 30595698 | doi = 10.1155/2018/3103061 | pmc = 6286736 | doi-access = free }}</ref>

=== Postoperative complications ===
Orbital emphysema is a common result of certain types of surgery, in particular the ones that involve [[Biology:Orbit (anatomy)|orbital medial wall]].<ref name=":3">{{cite journal | vauthors = Zimmer-Galler IE, Bartley GB | title = Orbital emphysema: case reports and review of the literature | journal = Mayo Clinic Proceedings | volume = 69 | issue = 2 | pages = 115–121 | date = February 1994 | pmid = 8309261 | doi = 10.1016/s0025-6196(12)61036-2 | doi-access = free }}</ref><ref name=":17">{{cite journal | vauthors = Jatla KK, Enzenauer RW | title = Orbital fractures: a review of current literature | journal = Current Surgery | volume = 61 | issue = 1 | pages = 25–29 | date = 1 January 2004 | pmid = 14972167 | doi = 10.1016/j.cursur.2003.08.003 }}</ref> It may also occur in other [[Medicine:Oral and maxillofacial surgery|oral]], nasal, and [[Medicine:Oral and maxillofacial surgery|maxillofacial]] surgical interventions, in which the occurrence is unexpected.<ref name=":16">{{cite journal | vauthors = Gauguet JM, Lindquist PA, Shaffer K | title = Orbital Emphysema Following Ocular Trauma and Sneezing | journal = Radiology Case Reports | volume = 3 | issue = 1 | pages = 124 | date = 1 January 2008 | pmid = 27303505 | doi = 10.2484/rcr.v3i1.124 | pmc = 4896116 }}</ref><ref>{{cite journal | vauthors = Ellis E | title = Orbital trauma | journal = Oral and Maxillofacial Surgery Clinics of North America | volume = 24 | issue = 4 | pages = 629–648 | date = November 2012 | pmid = 22981078 | doi = 10.1016/j.coms.2012.07.006 }}</ref><ref name="Periorbital Emphysema After Endosco">{{cite journal | vauthors = Çınar E, Yüce B, Fece M, Küçükerdönmez FC | title = Periorbital Emphysema After Endoscopic Nasal Polyp Surgery | journal = Turkish Journal of Ophthalmology | volume = 49 | issue = 1 | pages = 47–50 | date = February 2019 | pmid = 30829026 | doi = 10.4274/tjo.galenos.2018.01460 | pmc = 6416481 }}</ref> They can weaken [[Medicine:Paranasal sinuses|sinuses]], bony structure, induce deep orbital tissue damages, or [[Medicine:Globe rupture|globe perforation]] that cause air leakage into the periorbital soft tissues and superiorly into the supraorbital fat.<ref name=":16" /><ref name=":19">{{cite journal | vauthors = Lee SL, Mills DM, Meyer DR, Silver SM | title = Orbital emphysema | journal = Ophthalmology | volume = 113 | issue = 11 | pages = 2113.e1–2113.e2 | date = November 2006 | pmid = 17074576 | doi = 10.1016/j.ophtha.2006.06.013 }}</ref><ref name=":18">{{cite journal | vauthors = Shinohara H, Shirota Y, Fujita K | title = Implication of differences in the incidence of orbital emphysema in ethmoidal and maxillary sinus fractures | journal = Annals of Plastic Surgery | volume = 53 | issue = 6 | pages = 565–569 | date = December 2004 | pmid = 15602254 | doi = 10.1097/01.sap.0000134538.44898.1f | s2cid = 38798670 }}</ref> These surgical procedures may possibly introduce [[Biology:Staphylococcus|staphylococci]], [[Biology:Streptococcus|streptococci]], and [[Biology:Anaerobic organism|anaerobic bacteria]] via a compromised bony wall that can cause periorbital infection.<ref name=":17" /> The corresponding weakened or degenerated tissues cannot withstand the sudden increase in intraocular pressure and impaired ocular perfusion, driven by severe coughing or [[Biology:Sneeze|sneezing]]. It subsequently results in air trapped in the periorbital subcutaneous tissue and the development of orbital emphysema, which is often mistaken as [[Medicine:Allergy|allergic reactions]].<ref name="Periorbital Emphysema After Endosco"/> Without proper management can lead to cardiac life-threatening conditions such as [[Medicine:Embolism|cardiopulmonary embolism]], [[Medicine:Cardiac tamponade|cardiac tamponade]], and respiratory distress, depending on the volume of air trapped under the facial soft tissues.<ref name=":16" /><ref name=":18" />

=== Infection ===
Infections can spread beyond their initial location, including lamina papyracea.<ref name=":16" />

== Signs and Symptoms ==
The signs and symptoms of orbital emphysema vary depending on the original cause, but it is preliminary associated with swelling, [[Medicine:Bruise|bruising]], and tenderness around the impacted eye.<ref>{{cite journal | vauthors = Delpachitra SN, Rahmel BB | title = Orbital fractures in the emergency department: a review of early assessment and management | journal = Emergency Medicine Journal | volume = 33 | issue = 10 | pages = 727–731 | date = October 2016 | pmid = 26358976 | doi = 10.1136/emermed-2015-205005 | s2cid = 26852304 }}</ref> It may also involve proptosis or the [[Medicine:Visual impairment|deterioration of vision]], typically [[Medicine:Diplopia|diplopia]].<ref name=":0" /><ref name=":2">{{cite journal | vauthors = Linberg JV | title = Orbital emphysema complicated by acute central retinal artery occlusion: case report and treatment | journal = Annals of Ophthalmology | volume = 14 | issue = 8 | pages = 747–749 | date = August 1982 | pmid = 7125471 }}</ref> The entrapped air may cause an acute increase in the intraocular pressure or vascular compromise that restrict [[Biology:Eye movement|ocular motility]], prohibit the closure of eyelids, and the loss of sensation over the upper cheek areas.<ref>{{cite journal | vauthors = Oluwole M, White P | title = Orbital floor fracture following nose blowing | journal = Ear, Nose, & Throat Journal | volume = 75 | issue = 3 | pages = 169–170 | date = March 1996 | doi = 10.1177/014556139607500313 | pmid = 8721022 | s2cid = 21943984 }}</ref>

Server entrapment in the soft tissues tends to stimulate [[Biology:Oculocardiac reflex|oculocardiac reflex]], which is likely to generate significant [[Medicine:Reflex syncope|vagal responses]] including nausea, [[Medicine:Dizziness|dizziness]], [[Medicine:Vomiting|vomiting]], [[Medicine:Bradycardia|bradycardia]], [[Medicine:Syncope|syncope]] and [[Medicine:Heart block|heart block]].<ref name=":0" /><ref name=":21"/> Without treating it promptly may subsequently result in compromisation of ocular function and [[Medicine:Visual impairment|visual impairment]].<ref name=":22">{{cite journal | vauthors = Harmer SG, Ethunandan M, Zaki GA, Brennan PA | title = Sudden transient complete loss of vision caused by nose blowing after a fracture of the orbital floor | journal = The British Journal of Oral & Maxillofacial Surgery | volume = 45 | issue = 2 | pages = 154–155 | date = March 2007 | pmid = 16026907 | doi = 10.1016/j.bjoms.2005.06.008 }}</ref><ref>{{cite journal | vauthors = Muhammad JK, Simpson MT | title = Orbital emphysema and the medial orbital wall: a review of the literature with particular reference to that associated with indirect trauma and possible blindness | journal = Journal of Cranio-Maxillo-Facial Surgery | volume = 24 | issue = 4 | pages = 245–250 | date = August 1996 | pmid = 8880451 | doi = 10.1016/s1010-5182(96)80008-4 }}</ref><ref>{{cite journal | vauthors = Hwang K, Kim DH, Lee HS | title = Orbital fracture due to high-pressure air injection | journal = The Journal of Craniofacial Surgery | volume = 22 | issue = 4 | pages = 1506–1507 | date = July 2011 | pmid = 21778848 | doi = 10.1097/SCS.0b013e31821d4c3a }}</ref>

== Pathophysiology ==
Orbital emphysema occurs following forceful injection of air into the soft tissues of the orbit through a breach in one of the [[Biology:Orbit (anatomy)|orbital walls]] which is typically associated with orbital fracture after blunt trauma, or less frequently with compressed air injuries, [[Medicine:Neoplasm|tumours]] and infections of the sinonasal region or complications after surgery.<ref name=":0" /><ref name=":7" /><ref name=":5" /><ref name=":6" />

Orbital emphysema develops after an orbital fracture in a three-step process.<ref name=":0" /><ref name=":5">{{cite journal | vauthors = Fleishman JA, Beck RW, Hoffman RO | title = Orbital emphysema as an ophthalmologic emergency | journal = Ophthalmology | volume = 91 | issue = 11 | pages = 1389–1391 | date = November 1984 | pmid = 6514309 | doi = 10.1016/s0161-6420(84)34135-5 }}</ref> After the fracture has occurred on one of the [[Biology:Orbit (anatomy)|orbital walls]], a sino-orbital communication is established.<ref name=":0" /><ref name=":12">{{cite journal | vauthors = Ababneh OH | title = Orbital, subconjunctival, and subcutaneous emphysema after an orbital floor fracture | journal = Clinical Ophthalmology | volume = 7 | pages = 1077–1079 | date = June 2013 | pmid = 23766631 | doi = 10.2147/opth.s44649 | pmc = 3678949 | doi-access = free }}</ref><ref name=":5" /><ref name=":6">{{cite journal | vauthors = Brady FA, Roser SM, Hieshima GB | title = Orbital emphysema | journal = The British Journal of Oral Surgery | volume = 14 | issue = 1 | pages = 65–71 | date = July 1976 | pmid = 1066158 | doi = 10.1016/0007-117x(76)90095-0 }}</ref><ref name=":11" /> The communication will allow air to be forced from the [[Medicine:Paranasal sinuses|sinuses]] into the [[Biology:Orbit (anatomy)|orbit]] in the presence of a pressure gradient from forceful expiratory efforts, nose-blowing or even a [[Biology:Sneeze|sneeze]].<ref name=":0" /><ref name=":7">{{cite journal | vauthors = Singh M, Phua VM, Sundar G | title = Sight-threatening orbital emphysema treated with needle decompression | journal = Clinical & Experimental Ophthalmology | volume = 35 | issue = 4 | pages = 386–387 | date = May 2007 | pmid = 17539798 | doi = 10.1111/j.1442-9071.2007.01494.x | s2cid = 28193380 }}</ref><ref name=":5" /><ref name=":6" /> Orbital emphysema is typically a harmless disorder because air escapes as quickly as it enters the fracture site, and the increase in intraorbital pressure is usually transient, lasting for as long as the [[Biology:Sneeze|sneeze]] or nose blowing.<ref name=":5" /> However, when orbital soft tissues, such as [[Chemistry:Fat|fat]],<ref name=":0" /> falls back on the sino-orbital communication,<ref name=":0" /><ref name=":16" /><ref name=":8">{{cite journal | vauthors = Lin CY, Tsai CC, Kao SC, Kau HC, Lee FL | title = Needle decompression in a patient with vision-threatening orbital emphysema | journal = Taiwan Journal of Ophthalmology | volume = 6 | issue = 2 | pages = 93–95 | date = 1 June 2016 | pmid = 29018719 | pmc = 5602697 | doi = 10.1016/j.tjo.2015.02.003 }}</ref><ref name=":5" /> a [[Engineering:Check valve|one-way ball valve]] will be created, leading to the entrapment of air.<ref name=":0" /><ref name=":16" /><ref name=":7" /><ref name=":8" /><ref name=":1" /><ref name=":9">{{cite journal | vauthors = Roelofs KA, Starks V, Yoon MK | title = Orbital Emphysema: A Case Report and Comprehensive Review of the Literature | journal = Ophthalmic Plastic and Reconstructive Surgery | volume = 35 | issue = 1 | pages = 1–6 | date = 1 January 2019 | pmid = 30130334 | doi = 10.1097/iop.0000000000001216 | s2cid = 52054981 }}</ref><ref name=":5" /> When sufficient air accumulates, it will result in [[Medicine:Compartment syndrome|acute compartment syndrome]] and vascular compromise,<ref name=":0" /><ref name=":7" /><ref name=":8" /> causing complications including proptosis, [[Medicine:Visual impairment|visual impairment]], [[Medicine:Central retinal artery occlusion|central retinal artery occlusion]], compressive [[Medicine:Optic neuropathy|optic neuropathy]], and other severe complications caused by [[Medicine:Compartment syndrome|orbital compartment syndrome]].<ref name=":16" /><ref name=":8" /><ref name=":9" />

There are three variations of orbital emphysema, namely palpebral emphysema, true orbital emphysema, and orbitopalpebral emphysema.<ref name=":3" /><ref name=":16" />

=== Palpebral emphysema ===
Palpebral emphysema refers to emphysema of the eyelids alone. It is a rare kind of orbital emphysema which is usually caused by fractures of the [[Biology:Lacrimal bone|lacrimal bone]].<ref name=":3" /><ref name=":16" /><ref name=":4">{{cite journal | vauthors = Lloyd GA | title = Orbital emphysema | journal = The British Journal of Radiology | volume = 39 | issue = 468 | pages = 933–938 | date = December 1966 | pmid = 5954092 | doi = 10.1259/0007-1285-39-468-933 }}</ref> The [[Medicine:Lacrimal sac|lacrimal sac]] ruptures as a result of the fracture, allowing air from the nasal cavity to enter the [[Biology:Eyelid|tissues of the eyelid]].<ref name=":3" /><ref name=":4" /> Alternatively, facial subcutaneous air may simply pass into the eyelids along fascial plane to produce palpebral emphysema. As long as the [[Medicine:Orbital septum|orbital septum]] is intact, air is confined in the eyelids.<ref name=":3" />

=== True orbital emphysema ===
True orbital emphysema occurs when there is air behind an intact [[Medicine:Orbital septum|orbital septum]].<ref name=":3" /><ref name=":16" /><ref name=":4" /> This condition arises due to a fracture of more than one bony orbital walls of [[Medicine:Paranasal sinuses|paranasal sinuses]] and tearing of adjacent sinus mucosa, and communication of a sinus with the [[Biology:Orbit (anatomy)|orbit]] is established. This fracture usually involves the ethmoid, and sometimes involves frontal, sphenoid, and maxillary sinuses.<ref name=":3" /><ref name=":16" /><ref name=":4" /> The air usually enters the [[Biology:Orbit (anatomy)|orbit]] when the pressure within the [[Medicine:Respiratory tract|upper respiratory tract]] is increased due to expiratory efforts, nose blowing or [[Biology:Sneeze|sneezing]].<ref name=":3" />

=== Orbitopalperbal emphysema ===
Orbitopalpebral emphysema refers to the trapping of air inside both the soft tissues of the [[Biology:Orbit (anatomy)|orbit]] and the [[Biology:Eyelid|eyelid]]. It is usually a sequelae of a true orbital emphysema.<ref name=":3" /><ref name=":4" /> When too much air accumulates inside the [[Biology:Orbit (anatomy)|orbit]], the [[Medicine:Orbital septum|orbital septum]] ruptures due to high intraorbital pressure. Air may then pass freely from the [[Biology:Orbit (anatomy)|orbit]] into the [[Biology:Eyelid|eyelid]]s through the break in the [[Medicine:Orbital septum|orbital septum]].<ref name=":3" /><ref name=":4" />

== Stages ==
There are four stages of orbital emphysema.<ref name=":0">{{cite journal | vauthors = Hunts JH, Patrinely JR, Holds JB, Anderson RL | title = Orbital emphysema. Staging and acute management | language = English | journal = Ophthalmology | volume = 101 | issue = 5 | pages = 960–966 | date = May 1994 | pmid = 8190488 | doi = 10.1016/S0161-6420(94)31230-9 }}</ref><ref name=":1">{{cite journal | vauthors = Shameer A, Pushker N, Lokdarshi G, Basheer S, Bajaj MS | title = Emergency Decompression of Orbital Emphysema with Elevated Intraorbital Pressure | journal = The Journal of Emergency Medicine | volume = 53 | issue = 3 | pages = 405–407 | date = September 2017 | pmid = 28992871 | doi = 10.1016/j.jemermed.2016.10.021 }}</ref>

=== Stage I ===
Stage I orbital emphysema can only be diagnosed with radiological films. There is only a small amount of intraorbital air, and the patient does not show any clinical signs or symptoms.<ref name=":0" /><ref name=":1" />

=== Stage II ===
Stage II orbital emphysema develops as the intraorbital air volume increases, causing the [[Biology:Eye|eye]]ball to displace horizontally or vertically (globe dystopia) or to protrude anteriorly (proptosis). The patient may experience [[Medicine:Diplopia|diplopia]] as a result of the globe displacement.<ref name=":0" /><ref name=":1" />

=== Stage III ===
Stage III orbital emphysema develops when the limits of spontaneous decompression are exceeded. The pressure will be transmitted to orbital tissues and then to the globe, resulting in an increase in [[Biology:Intraocular pressure|intraocular pressure]] which may cause [[Medicine:Visual impairment|visual loss]] when the nutrient vessels supplying the [[Biology:Optic nerve|optic nerve]] are compressed.<ref name=":0" /><ref name=":1" />

=== Stage IV ===
Stage IV orbital emphysema develops when the intraorbital air mass results in an [[Biology:Intraocular pressure|intraocular pressure]] of more than 60 to 70 mmHg. The significantly elevated [[Biology:Intraocular pressure|intraocular pressure]] will lead to [[Medicine:Central retinal artery occlusion|central retinal artery occlusion]], which may result in permanent and irreversible damage to the [[Biology:Retina|retina]].<ref name=":0" /><ref name=":1" />

== Clinical Diagnosis ==
The diagnosis of orbital emphysema is usually made by physical examination of the eyelids,<ref name=":10">{{cite journal | vauthors = Ariyoshi Y, Naito H, Yumoto T, Iida A, Yamamoto H, Fujisaki N, Aokage T, Tsukahara K, Yamada T, Mandai Y, Osako T, Nakao A | display-authors = 6 | title = Orbital Emphysema as a Consequence of Forceful Nose-Blowing: Report of a Case | journal = Case Reports in Emergency Medicine | volume = 2019 | pages = 4383086 | date = 18 June 2019 | pmid = 31316840 | pmc = 6604475 | doi = 10.1155/2019/4383086 | doi-access = free }}</ref><ref name=":11">{{cite journal | vauthors = Jordan DR, White GL, Anderson RL, Thiese SM | title = Orbital emphysema: a potentially blinding complication following orbital fractures | journal = Annals of Emergency Medicine | volume = 17 | issue = 8 | pages = 853–855 | date = August 1988 | pmid = 3394993 | doi = 10.1016/s0196-0644(88)80571-7 }}</ref> and, or by [[CT scan|computer tomography]] (CT).<ref name=":10" /><ref name=":3" /><ref name=":16" /><ref name=":1" /><ref name=":6" /><ref name=":13">{{cite journal | vauthors = Birrer RB, Robinson T, Papachristos P | title = Orbital emphysema: how common, how significant? | journal = Annals of Emergency Medicine | volume = 24 | issue = 6 | pages = 1115–1118 | date = December 1994 | pmid = 7978593 | doi = 10.1016/s0196-0644(94)70241-1 }}</ref><ref name=":14">{{cite journal | vauthors = Gonzalez F, Cal V, Elhendi W | title = Orbital emphysema after sneezing | journal = Ophthalmic Plastic and Reconstructive Surgery | volume = 21 | issue = 4 | pages = 309–311 | date = July 2005 | pmid = 16052149 | doi = 10.1097/01.iop.0000170415.93858.6f }}</ref>

=== Physical examination ===
Physical examination of the [[Biology:Eyelid|eyelid]] can be done by the palpation for the pathognomonic cracking, crepitation,<ref name=":10" /> and tense tissue<ref name=":11" /> on the upper and lower [[Biology:Eyelid|eyelid]]s. The findings of the examination are supported with the [[Medicine:Medical history|medical history]] of the patient and confirmed with orbital [[CT scan|CT]].<ref name=":3" />

=== Computed tomography (CT) ===
[[File:Post-traumatic-orbital-emphysema.jpg|thumb|[[CT scan|CT scan]] taken from the transverse plane demonstrating orbital emphysema.<ref name=":24">{{Cite web| vauthors = Karapasias N |date=1 November 2013|title=Post traumatic orbital emphysema {{!}} Radiology Case {{!}} Radiopaedia.org|url=https://radiopaedia.org/cases/post-traumatic-orbital-emphysema|access-date=15 April 2021|website=Radiopaedia|language=en-US}}</ref>]]
[[File:Post-traumatic-orbital-emphysema-2.jpg|thumb|[[CT scan|CT scan]] taken from the coronal plane demonstrating orbital emphysema.<ref name=":24" />]]
[[CT scan|Computed tomography]] is effective and sensitive in the diagnosis of orbital emphysema,<ref name=":16" /><ref name=":13" /> as it can confirm the anatomical location and size of air, bony defects, indentation of the eyeball, and the condition of the [[Biology:Optic nerve|optic nerve]], as well as the presence of any extraocular muscle entrapment and herniation of preorbital fat into the sinus cavities.<ref name=":16" /><ref name=":1" /><ref name=":14" /> The location of the orbital emphysema is present near the site of the fracture.<ref name=":0" /><ref name=":16" /> The scans are usually taken along the [[Biology:Transverse plane|transverse plane]]. Transverse images allow the evaluation of fractures in [[Biology:Orbit (anatomy)|medial and lateral orbital walls]]. By reformatting these transverse images or taking [[Biology:Coronal plane|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.<ref name=":16" /> The staging of orbital emphysema can then be determined with [[Biology:Visual acuity|visual acuity]] examination and [[Physics:Ophthalmoscopy|ophthalmoscopy]].<ref name=":3" /> 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’ [[Medicine:Medical history|medical history]] is crucial in making the correct diagnosis.<ref name=":16" />

=== Other tests ===
Conventional [[Physics:Radiography|radiography]] is commonly employed for imaging orbital injuries and identifying orbital fractures.<ref name=":16" /> 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.<ref name=":16" /> Skull films of posterior-anterior, lateral projections, and orbital rim views are recommended to show fractures in [[Biology:Orbit (anatomy)|orbital rims]] and [[Biology:Orbit (anatomy)|walls]].<ref name=":6" /> However, [[CT scan]] is better than conventional radiography in the diagnosis of the condition,<ref name=":16" /><ref name=":13" /> as it has a lower high false-negative rate and non-diagnostic rate.<ref name=":16" />

Orbital emphysema can also be diagnosed by [[Physics:Magnetic resonance imaging|magnetic resonance imaging (MRI)]]. Although [[Physics:Magnetic resonance imaging|MRI]] has a low sensitivity for detecting orbital fractures, it can be used to evaluate rectus muscle pathology, [[Biology:Optic nerve|optic nerve]] pathology, and [[Biology:Brain|brain]] pathology, as well as vascular injury.<ref name=":16" />

== Treatment ==
Orbital emphysema on its own is a mild and self-limiting disease.<ref name=":0" /><ref name=":3" /><ref name=":12" /> The majority of cases of orbital emphysema are self-resolving<ref name=":3" /><ref name=":12" /><ref name=":9" /> and do not need treatment.<ref name=":10" /><ref name=":15">{{cite journal | vauthors = Tsai SH, Chu SJ | title = Orbital emphysema | journal = The Journal of Trauma | volume = 65 | issue = 5 | pages = 1200 | date = November 2008 | pmid = 18277265 | doi = 10.1097/01.ta.0000236035.18788.9c }}</ref><ref name=":12" /><ref name=":9" /><ref name=":6" /><ref name=":4" /> The underlying causes and injuries that caused orbital emphysema, on the other hand, may be serious, necessitating urgent intervention including surgery.<ref name=":6" /><ref name=":4" /> If related visual symptoms or other acute orbital compression symptoms are present,<ref name=":15" /> [[Medicine:Canthus|lateral canthotomy or cantholysis]], orbital decompression by needle aspiration,<ref name=":7" /><ref name=":8" /> and bone decompression<ref name=":10" /><ref name=":3" /><ref name=":19" /><ref name=":12" /><ref name=":1" /><ref name=":9" /> may be required to relieve orbital pressure and preserve vision. [[Chemistry:Antibiotic|Prophylactic oral antibiotics]] may be needed to prevent secondary infection.<ref name=":0" /><ref name=":5" />

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== Reference list ==
{{Reflist}}

[[Category:Ophthalmology]]

{{Sourceattribution|Orbital emphysema}}