Orbital Cellulitis (OC) is a serious bacterial infection that develops in the soft tissues and fat located deep within the eye socket, behind the orbital septum. This condition is a medical emergency because the infection occurs in a confined space, which can quickly lead to increased pressure and severe complications. The resulting inflammation can compress nerves and blood vessels, requiring prompt and aggressive medical intervention to prevent permanent damage.
Is Orbital Cellulitis Transmissible?
Orbital cellulitis is not a contagious condition that can be spread from one person to another through casual contact, coughing, or sneezing. This infection is considered endogenous, meaning it originates from the spread of bacteria already present within the affected individual’s own body. The infection arises when existing bacterial colonies migrate from a nearby location to the orbital tissues. Therefore, a person with Orbital Cellulitis poses no direct risk of transmitting the condition to family members or close contacts. The specific infection of the orbit is not a communicable disease, even though the bacteria involved (such as Staphylococcus or Streptococcus species) can be found elsewhere on the body.
Understanding the Source of the Infection
The bacteria responsible for Orbital Cellulitis typically reach the orbit by spreading from an adjacent area of infection. The most common preceding condition is acute bacterial rhinosinusitis, particularly an infection in the ethmoid sinus, which lies next to the eye socket. Up to 98% of cases stem from an untreated bacterial sinus infection that has spread behind the orbital septum. Other potential entry points include recent facial trauma or injury that penetrates the orbital septum, such as an animal bite or a deep wound, or dental infections involving the upper jaw that track upward. The bacteria most frequently implicated are Staphylococcus aureus and various Streptococcus species.
Key Differences Between Orbital and Preseptal Cellulitis
The distinction between Orbital Cellulitis (OC) and Preseptal Cellulitis (PC) is based on the orbital septum, a fibrous membrane that acts as a physical barrier. Preseptal Cellulitis, often called periorbital cellulitis, is an infection limited to the tissues in front of this septum, involving the eyelid and surrounding skin. Orbital Cellulitis, by contrast, involves the fat, muscles, and soft tissues located behind the septum, within the eye socket itself. This deeper location makes OC significantly more dangerous and requires different treatment, with key differentiating symptoms including pain when moving the eye, proptosis (a noticeable forward bulging of the eyeball), and any changes in vision. Preseptal Cellulitis typically presents with eyelid swelling and redness, but eye movement and visual acuity remain unaffected.
Necessary Medical Intervention and Urgency
Orbital Cellulitis demands immediate medical attention and is treated as an emergency. Due to the risk of rapid progression to permanent vision loss, meningitis, or a blood clot in the brain (cavernous sinus thrombosis), prompt hospitalization is required. Treatment involves immediately administering intravenous (IV) broad-spectrum antibiotics. Imaging, typically a contrast-enhanced Computed Tomography (CT) scan or Magnetic Resonance Imaging (MRI), is necessary to confirm the postseptal location of the infection and check for abscess formation. If a walled-off collection of pus, known as an orbital abscess, is identified, surgical drainage may be required in addition to the IV antibiotic regimen.