1. ORBITAL CELLULITIS Orbital cellulitis is an acute infection of the tissues immediately surrounding the eye, including the eyelids, eyebrow, and cheek

2. PATHOPHYSIOLOGY results from microbial infection with subsequent inflammation of the post-septal aspect of the eyelids most common routes of infection: – adjacent sinuses or teeth – direct inoculation through penetrating lid injury Common organisms include: – Staphylococcus aureus – Streptococcus pyogenes – Streptococcus pneumoniae – Haemophilus influenzae in children

3. SIGNS AND SYMPTOMS history of upper respiratory tract infection with or without nasal discharge may be present swelling and redness of the eyelid and surrounding soft tissues conjunctival hyperemia decreased ocular motility pain with eye movements decreased visual acuity proptosis caused by orbital swelling fever, malaise, and headache (should raise suspicion of associated meningitis) afferent pupil defect