Description

• Acute, severe, vision-threatening infection of orbital contents posterior to the orbital septum; preseptal (previously referred to as periorbital) cellulitis is anterior to the septum. Location determines the appropriate workup and treatment.
• Synonym(s): postseptal cellulitis

Epidemiology

• No difference in frequency between genders in adults. Higher incidence in boys in childhood; more common in children
• Orbital cellulitis is much less common than preseptal cellulitis (1).

Incidence
The incidence of orbital cellulitis has declined since introduction of routine Haemophilus influenzae type b (Hib) vaccination.

Etiology and Pathophysiology

• Sinusitis is classically associated with orbital cellulitis. Local skin conditions surrounding the eyelids and lashes are typically associated with preseptal cellulitis. The ethmoid sinus is separated from the orbit by the lamina papyracea (“layer of paper”), a thin bony separation, and is often the source of contiguous spread of infection to the orbit. The ethmoid sinus is present at birth. The orbital septum is a connective tissue barrier that extends from the skull into the lid and separates the preseptal from the orbital space.
• Cellulitis in the closed bony orbit causes proptosis, globe displacement, orbital apex syndrome (mass effect on the cranial nerves), optic nerve compression, and vision loss.
• Cultures of surgical specimens in adults often grow multiple organisms. In over 1/3 of cases, no pathogen is recovered. Blood cultures typically do not grow an organism.
• Most common organisms: Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus anginosus
• Haemophilus is no longer the leading cause of orbital cellulitis. MRSA is increasingly a consideration.

Genetics
No known genetic predisposition

Risk Factors

• Sinusitis (present in 80–100% of cases); pansinusitis is often observed in adults (1).
• Orbital trauma, retained orbital foreign body (FB), ophthalmic surgery, and/or history of sinus surgery (1)
• Dental, periorbital, skin, or intracranial infection; acute dacryocystitis (inflammation of the lacrimal sac) and acute dacryoadenitis (inflammation of the lacrimal gland)
• Immunosuppressed patients are at increased risk of adverse outcomes.

General Prevention

Routine Hib vaccination; appropriate treatment of bacterial sinusitis; proper wound care and perioperative monitoring of orbital surgery and trauma; avoid trauma to the sinus and orbital regions

Commonly Associated Conditions

• Sinusitis, especially pansinusitis in adults; trauma and intraorbital FB; preseptal cellulitis
• Adverse outcomes include neutropic keratitis, secondary glaucoma, septic uveitis or retinitis, exudative retinal detachment, meningitis, cranial nerve palsies, panophthalmitis, inflammatory or infectious neuritis, retinal vein occlusion, central retinal artery occlusion, orbital abscess, subperiosteal abscess, orbital apex syndrome, subdural or brain abscess, and death.