Orbital Cellulitis

Bacterial Orbital Cellulitis is a life threatening infection of the soft tissues behind the orbital septum. It's most common in children. Most often the causes are strep. pneumoniae, Staph. aureus, Strep, pyogenes and H. Influenzae.

Causes

• Sinus related
• Extension of preseptal cellulitis through the orbital septum
• Local spread from adjacent dacryocystitis/mid-facial dental infection
• Haematogenous spread
• Post traumatic - develops within 72 hours of an injury that penetrated the orbital septum
• Post surgical - retinal, lacrimal or orbital surgery

Features

• Presents w/rapid onset of severe malaise, fever, pain and visual impairment
• Unilateral, tender, warm & red periorbital and lid oedema
• Proptosis, often obscured by lid swelling
• Painful ophthalmoplegia
• Optic nerve dysfunction

Complications

• Exposure keratopathy, raised IOP, occulsion of central retinal artery/vein, endophthalmitis and optic neuropathy
• Intracranial complications are rare but include meningitis, brain abscess and cavernous sinus thrombosis (rare but extremely serious - suspect if evidence of bilateral involvement and abrupt progression of clinical signs assoc w/prostration, severe headache, nausea, vomiting
• Subperiosteal abscess is most frequently located along the medial orbital wall. Serious as it can progress rapidly and extend intracrainially
• Orbital abscess (relatively rare)

Management

• Hospital! Needs frequency ophthalmological assessment
• Antibiotic therapy
• Monitoring of ON function with pupillary reactions, VA, colour vision and light brightness appreciation.
• Investigate white cell count, blood culture, CT scan of orbit, sinuses and brain
• Lumbar puncture if intracranial signs develop
• Surgical intervention if vision decreasing, px not responding to antibiotics, orbital/subperiosteal abscess
• It's usual necessary to drain the infected sinuses as well as the orbit.