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 In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...

that is generally characterized by sudden onset swelling and

bruising A bruise, also known as a contusion, is a type of hematoma of tissue, the most common cause being capillaries damaged by trauma, causing localized bleeding that extravasates into the surrounding interstitial tissues. Most bruises occur clo ...

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 A sneeze (also known as sternutation) is a semi-autonomous, convulsive expulsion of air from the lungs through the nose and mouth, usually caused by foreign particles irritating the nasal mucosa. A sneeze expels air forcibly from the mouth a ...

, nose blowing, or

cough A cough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles and Microorganism, microbes. As a protective reflex, coughing can be repetitive with the cough reflex fol ...

ing 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 An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...

esophageal rupture Esophageal rupture, also known as Boerhaave syndrome, is a rupture of the esophageal wall. Iatrogenic causes account for approximately 56% of esophageal perforations, usually due to medical instrumentation such as an endoscopy or paraesophageal s ...

, postoperative complications,

pulmonary barotrauma Barotrauma is physical damage to body tissues caused by a difference in pressure between a gas space inside, or in contact with, the body and the surrounding gas or liquid. The initial damage is usually due to over-stretching the tissues in ...

, with the same predisposing factors (

, nose blowing, or

ing). A four-stage system of orbital emphysema was developed for severity classification. Clinical diagnosis can be made based on a combination of

medical history The medical history, case history, or anamnesis (from Greek: ἀνά, ''aná'', "open", and μνήσις, ''mnesis'', "memory") of a patient is a set of information the physicians collect over medical interviews. It involves the patient, and ev ...

physical examination In a physical examination, medical examination, clinical examination, or medical checkup, a medical practitioner examines a patient for any possible medical signs or symptoms of a Disease, medical condition. It generally consists of a series of ...

, and

computed tomography A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

. 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. Any object with force and/or speed, typically a ball, fist or vehicle accidents, can result in orbital floor and/or medial wall fractures. These disruptions permit air entry into the orbital subcutaneous from the

sinus Sinus may refer to: History * a sac in front of body worn into a toga, in the typical style of wearing it Anatomy * Sinus (anatomy), a sac or cavity in any organ or tissue ** Paranasal sinuses, air cavities in the cranial bones, especially those ...

, with a one-way check valve mechanism that forbids the air from exiting. 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

nose-blowing Nose-blowing is the act of expelling nasal mucus by exhaling forcefully through the nose. This is usually done into a facial tissue or handkerchief, facial tissues being more hygienic as they are disposed of after each use while handkerchiefs are ...

, or

ing. These generate an acute increase in intraorbital pressure, compromising the intraorbital neurovascular structures, which subsequently trigger the development of orbital emphysema.

Postoperative complications

Orbital emphysema is a common result of certain types of surgery, in particular the ones that involve orbital medial wall. It may also occur in other

oral The word oral may refer to: Relating to the mouth * Relating to the mouth, the first portion of the alimentary canal that primarily receives food and liquid **Oral administration of medicines ** Oral examination (also known as an oral exam or ora ...

, nasal, and

maxillofacial Oral and maxillofacial surgery (OMFS) is a surgical specialty focusing on reconstructive surgery of the face, facial trauma surgery, the mouth, head and neck, and jaws, as well as facial plastic surgery including cleft lip and cleft palate s ...

surgical interventions, in which the occurrence is unexpected. They can weaken

sinuses Paranasal sinuses are a group of four paired air-filled spaces that surround the nasal cavity. The maxillary sinuses are located under the eyes; the frontal sinuses are above the eyes; the ethmoidal sinuses are between the eyes and the sphenoi ...

, bony structure, induce deep orbital tissue damages, or globe perforation that cause air leakage into the periorbital soft tissues and superiorly into the supraorbital fat. These surgical procedures may possibly introduce

staphylococci ''Staphylococcus'', from Ancient Greek σταφυλή (''staphulḗ''), meaning "bunch of grapes", and (''kókkos''), meaning "kernel" or " Kermes", is a genus of Gram-positive bacteria in the family Staphylococcaceae from the order Bacillale ...

streptococci ''Streptococcus'' is a genus of gram-positive spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occurs along a sing ...

, and

anaerobic bacteria An anaerobic organism or anaerobe is any organism that does not require molecular oxygen for growth. It may react negatively or even die if free oxygen is present. In contrast, an aerobic organism (aerobe) is an organism that requires an oxygenat ...

via a compromised bony wall that can cause periorbital infection. The corresponding weakened or degenerated tissues cannot withstand the sudden increase in intraocular pressure and impaired ocular perfusion, driven by severe

ing or

. It subsequently results in air trapped in the periorbital subcutaneous tissue and the development of orbital emphysema, which is often mistaken as

allergic reactions Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, alle ...

. Without proper management can lead to cardiac life-threatening conditions such as cardiopulmonary embolism,

cardiac tamponade Cardiac tamponade, also known as pericardial tamponade (), is a compression of the heart due to pericardial effusion (the build-up of pericardial fluid in the pericardium, sac around the heart). Onset may be rapid or gradual. Symptoms typically i ...

, and

respiratory distress Shortness of breath (SOB), known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that c ...

, depending on the volume of air trapped under the facial soft tissues.

Infection

Infections can spread beyond their initial location, including

lamina papyracea The orbital lamina of ethmoid bone (or lamina papyracea or orbital lamina) is a smooth, oblong, paper-thin bone plate which forms the lateral wall of the labyrinth of the ethmoid bone. It covers the middle and posterior ethmoidal cells, and forms ...

Signs and Symptoms

The signs and symptoms of orbital emphysema vary depending on the original cause, but it is preliminary associated with swelling,

, and tenderness around the impacted eye. It may also involve

proptosis Exophthalmos (also called exophthalmus, exophthalmia, proptosis, or exorbitism) is a bulging of the eye anteriorly out of the orbit. Exophthalmos can be either bilateral (as is often seen in Graves' disease) or unilateral (as is often seen in ...

or the deterioration of vision, typically

diplopia Diplopia is the simultaneous perception of two images of a single object that may be displaced in relation to each other. Also called double vision, it is a loss of visual focus under regular conditions, and is often voluntary. However, when occ ...

. The entrapped air may cause an acute increase in the intraocular pressure or vascular compromise that restrict ocular motility, prohibit the closure of eyelids, and the loss of sensation over the upper cheek areas. Server entrapment in the soft tissues tends to stimulate

oculocardiac reflex The oculocardiac reflex, also known as Aschner phenomenon, Aschner reflex, or Aschner–Dagnini reflex, is a decrease in pulse rate associated with traction applied to extraocular muscles and/or compression of the eyeball. The reflex is mediated b ...

, which is likely to generate significant vagal responses including

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...

dizziness Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to Balance disorder, disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a ...

vomiting Vomiting (also known as emesis, puking and throwing up) is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteritis, pre ...

bradycardia Bradycardia, also called bradyarrhythmia, is a resting heart rate under 60 beats per minute (BPM). While bradycardia can result from various pathological processes, it is commonly a physiological response to cardiovascular conditioning or due ...

, syncope and

heart block Heart block (HB) is a disorder in the heart's rhythm due to a fault in the natural pacemaker. This is caused by an obstruction – a block – in the electrical conduction system of the heart. Sometimes a disorder can be inherited. Despite the ...

. Without treating it promptly may subsequently result in compromisation of ocular function and

visual impairment Visual or vision impairment (VI or VIP) is the partial or total inability of visual perception. In the absence of treatment such as corrective eyewear, assistive devices, and medical treatment, visual impairment may cause the individual difficul ...

Pathophysiology

Orbital emphysema occurs following forceful injection of air into the soft tissues of the orbit through a breach in one of the orbital walls which is typically associated with orbital fracture after blunt trauma, or less frequently with compressed air injuries,

tumours A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

and infections of the sinonasal region or complications after surgery. Orbital emphysema develops after an orbital fracture in a three-step process. After the fracture has occurred on one of the orbital walls, a sino-orbital communication is established. The communication will allow air to be forced from the

into the

in the presence of a pressure gradient from forceful expiratory efforts,

or even a

sneeze A sneeze (also known as sternutation) is a semi-autonomous, convulsive expulsion of air from the lungs through the nose and mouth, usually caused by foreign particles irritating the nasal mucosa. A sneeze expels air forcibly from the mouth a ...

. 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

or nose blowing. However, when orbital soft tissues, such as

fat In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food. The term often refers specif ...

, falls back on the sino-orbital communication, a one-way ball valve will be created, leading to the entrapment of air. When sufficient air accumulates, it will result in acute compartment syndrome and vascular compromise, causing complications including

central retinal artery occlusion Central retinal artery occlusion (CRAO) is a disease of the eye where the flow of blood through the central retinal artery is blocked (occluded). There are several different causes of this occlusion; the most common is carotid artery atheroscle ...

, compressive

optic neuropathy Optic neuropathy is damage to the optic nerve from any cause. The optic nerve is a bundle of millions of fibers in the retina that sends visual signals to the brain. Damage and death of these nerve cells, or neurons, leads to characteristic featu ...

, and other severe complications caused by orbital compartment syndrome. There are three variations of orbital emphysema, namely palpebral emphysema, true orbital emphysema, and orbitopalpebral emphysema.

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

lacrimal bone The lacrimal bones are two small and fragile bones of the facial skeleton; they are roughly the size of the little fingernail and situated at the front part of the medial wall of the orbit. They each have two surfaces and four borders. Several bon ...

. The

lacrimal sac The lacrimal sac or lachrymal sac is the upper dilated end of the nasolacrimal duct, and is lodged in a deep groove formed by the lacrimal bone and frontal process of the maxilla. It connects the lacrimal canaliculi, which drain tears from th ...

ruptures as a result of the fracture, allowing air from the

nasal cavity The nasal cavity is a large, air-filled space above and behind the nose in the middle of the face. The nasal septum divides the cavity into two cavities, also known as fossae. Each cavity is the continuation of one of the two nostrils. The nas ...

to enter the tissues of the eyelid. Alternatively, facial subcutaneous air may simply pass into the eyelids along fascial plane to produce palpebral emphysema. As long as the

orbital septum In anatomy, the orbital septum (palpebral fascia) is a membranous sheet that acts as the anterior (frontal) boundary of the orbit. It extends from the orbital rims to the eyelids. It forms the fibrous portion of the eyelids. Structure In the ...

is intact, air is confined in the eyelids.

True orbital emphysema

True orbital emphysema occurs when there is air behind an intact

. This condition arises due to a fracture of more than one bony orbital walls of

paranasal sinuses Paranasal sinuses are a group of four paired air-filled spaces that surround the nasal cavity. The maxillary sinuses are located under the eyes; the frontal sinuses are above the eyes; the ethmoidal sinuses are between the eyes and the sphe ...

and tearing of adjacent sinus mucosa, and communication of a sinus with the

is established. This fracture usually involves the

ethmoid The ethmoid bone (; from ) is an unpaired bone in the skull that separates the nasal cavity from the brain. It is located at the roof of the nose, between the two orbit (anatomy), orbits. The cubical (cube-shaped) bone is lightweight due to a sp ...

, and sometimes involves frontal, sphenoid, and

maxillary sinus The pyramid-shaped maxillary sinus (or antrum of Nathaniel Highmore (surgeon), Highmore) is the largest of the paranasal sinuses, located in the maxilla. It drains into the middle meatus of the noseHuman Anatomy, Jacobs, Elsevier, 2008, page 209- ...

es. The air usually enters the

when the pressure within the

upper respiratory tract The respiratory tract is the subdivision of the respiratory system involved with the process of conducting air to the alveoli for the purposes of gas exchange in mammals. The respiratory tract is lined with respiratory epithelium as respiratory ...

is increased due to expiratory efforts, nose blowing or

Orbitopalperbal emphysema

Orbitopalpebral emphysema refers to the trapping of air inside both the soft tissues of the

and the

eyelid An eyelid ( ) is a thin fold of skin that covers and protects an eye. The levator palpebrae superioris muscle retracts the eyelid, exposing the cornea to the outside, giving vision. This can be either voluntarily or involuntarily. "Palpebral ...

. It is usually a sequelae of a true orbital emphysema. When too much air accumulates inside the

, the

ruptures due to high intraorbital pressure. Air may then pass freely from the

into the

s through the break in the

Stages

There are four stages of orbital emphysema.

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.

Stage II

Stage II orbital emphysema develops as the intraorbital air volume increases, causing the

eye An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

ball to displace horizontally or vertically (globe dystopia) or to protrude anteriorly (

). The patient may experience

as a result of the globe displacement.

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

intraocular pressure Intraocular pressure (IOP) is the fluid pressure inside the eye. Tonometry is the method eye care professionals use to determine this. IOP is an important aspect in the evaluation of patients at risk of glaucoma. Most tonometers are calibrated t ...

which may cause

visual loss Visual or vision impairment (VI or VIP) is the partial or total inability of visual perception. In the absence of treatment such as corrective eyewear, assistive devices, and medical treatment, visual impairment may cause the individual difficul ...

when the nutrient vessels supplying the

optic nerve In neuroanatomy, the optic nerve, also known as the second cranial nerve, cranial nerve II, or simply CN II, is a paired cranial nerve that transmits visual system, visual information from the retina to the brain. In humans, the optic nerve i ...

are compressed.

Stage IV

Stage IV orbital emphysema develops when the intraorbital air mass results in an

of more than 60 to 70 mmHg. The significantly elevated

will lead to

, which may result in permanent and irreversible damage to the

retina The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional ...

Clinical Diagnosis

The diagnosis of orbital emphysema is usually made by

of the eyelids, and, or by

computer tomography A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

(CT).

Physical examination

Physical examination In a physical examination, medical examination, clinical examination, or medical checkup, a medical practitioner examines a patient for any possible medical signs or symptoms of a Disease, medical condition. It generally consists of a series of ...

of the

can be done by the

palpation Palpation is the process of using one's hands to check the body, especially while perceiving/diagnosing a disease or illness. Usually performed by a health care practitioner, it is the process of feeling an object in or on the body to determine ...

for the pathognomonic cracking, crepitation, and tense tissue on the upper and lower

s. The findings of the examination are supported with the

of the patient and confirmed with orbital CT.

Computed tomography (CT)

Computed tomography A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

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

, 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 A transverse plane is a plane that is rotated 90° from two other planes. Anatomy The transverse plane is an anatomical plane that is perpendicular to the sagittal plane and the dorsal plane. It is also called the axial plane or horizonta ...

. Transverse images allow the evaluation of fractures in medial and lateral orbital walls. 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 Visual acuity (VA) commonly refers to the clarity of visual perception, vision, but technically rates an animal's ability to recognize small details with precision. Visual acuity depends on optical and neural factors. Optical factors of the eye ...

examination and

ophthalmoscopy Ophthalmoscopy, also called funduscopy, is a test that allows a health professional to see inside the fundus of the eye and other structures using an ophthalmoscope (or funduscope). It is done as part of an eye examination and may be done as part ...

. A disadvantage of using a

CT scan A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

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’

is crucial in making the correct diagnosis.

Other tests

Conventional

radiography Radiography is an imaging technology, imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical ("diagnostic" radiog ...

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 Walls may refer to: *The plural of wall, a structure * Walls (surname), a list of notable people with the surname Places * Walls, Louisiana, United States * Walls, Mississippi, United States *Walls, Ontario Perry is a township (Canada), ...

. However,

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 Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and rad ...

has a low sensitivity for detecting orbital fractures, it can be used to evaluate rectus muscle pathology,

pathology, and

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

pathology, as well as vascular injury.

Treatment

Orbital emphysema on its own is a mild and self-limiting disease. The majority of cases of orbital emphysema are self-resolving and do not need treatment. The underlying causes and injuries that caused orbital emphysema, on the other hand, may be serious, necessitating urgent intervention including surgery. 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. Prophylactic oral antibiotics may be needed to prevent secondary infection.

Reference list

{{Reflist Ophthalmology