Orbital Cellulitis: Pathogenesis and Clinical Findings Definitions: a. Chemosis: Edema of the bulbar conjunctiva b. Panopthalmitis: inflammation of all coats of the eye including intraocular structures. c. Endopthalmitis: inflammation of the interior of the eye. • Spreads to periorbital tissue (anterior to the orbital septum) -> Localized inflammation -> Conjunctival chemosis -> Eyelid and periorbital edema -> Pain on palpation -> Induration, Warmth • Inflammation of orbital tissue - Impinges on ocular muscles -> Impaired extra-ocular movements -> Pain with eye movement or opthalmoplegia - Impinges on nerves -> Afferent pupillary defect -> Decreased visual acuity - Proptosis -> Exposes cornea -> Corneal drying and scarring • Spreads to surrounding structures -> Subperiosteal abscess -> Brain abscess -> Cavernous sinus thrombosis -> Meningitis -> Subdural empyema -> Orbital abscess • Involves the orbit -> Panopthalmitis -> Endopthalmitis -> Blindness #Orbital #Cellulitis #pathophysiology #ophthalmology #diagnosis #signs #symptoms