Bacterial orbital cellulitis - A review.

Infections of orbit and periorbita are frequent, leading to significant morbidity. Orbital cellulitis is more common in children and young adults. At any age, infection from the neighboring ethmoid sinuses is a likely cause and is thought to result from anatomical characteristics like thin medial wall, lack of lymphatics, orbital foramina, and septic thrombophlebitis of the valveless veins between the two. Other causes are trauma, orbital foreign bodies, preexisting dental infections, dental procedures, maxillofacial surgeries, Open Reduction and Internal Fixation (ORIF), and retinal buckling procedures. The septum is a natural barrier to the passage of microorganisms. Orbital infections are caused by Gram-positive, Gram-negative organisms and anaerobes in adults and in children, usually by Staphylococcus aureus or Streptococcus species. Individuals older than 15 years of age are more likely to harbor polymicrobial infections. Signs include diffuse lid edema with or without erythema, chemosis, proptosis, and ophthalmoplegia. It is an ocular emergency requiring admission, intravenous antibiotics, and sometimes surgical intervention. Computed tomography (CT) and magnetic resonance imaging (MRI) are the main modalities to identify the extent, route of spread from adjacent structures, and poor response to intravenous antibiotics and to confirm the presence of complications. If orbital cellulitis is secondary to sinus infection, drainage of pus and establishment of ventilation to the sinus are imperative. Loss of vision can occur due to orbital abscess, cavernous sinus thrombosis, optic neuritis, central retinal artery occlusion, and exposure keratopathy, and possible systemic sequelae include meningitis, intracranial abscess, osteomyelitis, and death. The article was written by authors after a thorough literature search in the PubMed-indexed journals.