orbitalitis

Orbitalitis, or orbital inflammation, refers to inflammation of the orbital tissues behind the orbital septum. The term is commonly used to describe orbital cellulitis, a bacterial infection of the contents of the orbit that is an ocular emergency because it can threaten vision and spread to intracranial structures. It must be distinguished from preseptal cellulitis, which involves only the eyelid and surrounding soft tissues.

Causes include acute bacterial infection most often arising from paranasal sinusitis (particularly the ethmoid sinuses), dental infection, or facial trauma. Extension from preseptal cellulitis or direct inoculation during trauma are other routes. Noninfectious orbital inflammatory disease, such as idiopathic orbital inflammatory syndrome (orbital pseudotumor), is a separate category of orbital inflammation.

Clinical features of orbital cellulitis include fever, periorbital edema and erythema, proptosis, restricted and painful extraocular movements, and sometimes decreased visual acuity. Patients may have nasal congestion or sinus symptoms. In contrast, preseptal cellulitis typically lacks ophthalmoplegia and proptosis.

Diagnosis relies on clinical assessment supported by imaging. Contrast-enhanced CT or MRI of the orbits and sinuses helps delineate orbital involvement, sinus disease, and any abscess. Blood tests may show leukocytosis. Prompt evaluation by ophthalmology and otolaryngology is common.

Treatment for infectious orbital cellulitis requires hospitalization with intravenous broad-spectrum antibiotics that cover common orbital pathogens, including streptococci, staphylococci, and anaerobes. Surgical drainage is considered for orbital abscess or deterioration despite therapy. Noninfectious orbital inflammation may respond to corticosteroids after ruling out infection. Early treatment improves prognosis and reduces the risk of vision loss or intracranial complications.