Potentially serious infection of the eye.

Chandler classification describes the potential sequence of events:

• Preseptal (periorbital) cellulitis, in other words, anterior to the eye. Usually caused by skin organisms entering via superficial trauma
• Orbital cellulitis – surrounding the eye
• Subperiosteal orbital abscess – penetration into bone of orbit
• Orbital abscess
• Cavernous sinus thrombosis

In older children, more likely to start with sinusitis, then eroding through into orbit. Differentiating between these types is difficult without imaging.

Different organisms cf skin commensals of preseptal cellulitis eg Haemophilus, streptococci including pneumococcus, anaerobes.

Often no organism is obtained, which adds to the difficulty of giving evidence based guidance. Multiple bugs not uncommon. Hence a variety of different guidelines, generally of poor quality.

In a large US review of 220 children and young adults, 98% were investigated by CT. High rate of steroid use – previous studies have suggested better outcomes, but no obvious benefit in terms of treatment success here. Various antibiotic regimens, various durations. More treatment failures if treated for more than 3 weeks but these will be the most severe/complex cases.

Management

Jointly managed by ophthalmology, ENT and paediatrics. Ophthalmology are best at performing eye movement assessment, but it is ENT who tend to do any surgery (usually endoscopic sinus surgery).

Red flags:

• Severe proptosis,
• worsening visual acuity,
• elevated intraocular pressure,
• colour indiscrimination,
• intracranial involvement,
• inability to perform a reliable serial ophthalmologic examination,
• poor response to a trial of intravenous antibiotics for 24 to 48 hours

These are indications for surgery.

The size of any subperiosteal abscess on CT is a new prognostic factor: diameter >10mm and volumes ≥500mm3 (although volume measurements not routinely reported) are thought typically to require immediate surgical intervention, with the remainder going to surgery only in the event of clinical deterioration, lack of clinical improvement after 48 hours of antibiotics, or worsening abscess on imaging.

Treatment duration – most people would agree to IV treatment until clear improvement, followed by oral antibiotics for a total of 14 days.