Hypopyon
Background
- Collection of white blood cells (leukocytic exudate) layering in the anterior chamber of the eye
- A sign of severe intraocular inflammation — not a diagnosis itself
- Always indicates significant pathology requiring urgent evaluation
- Most common causes in EM: corneal ulcer (infectious keratitis), severe uveitis, endophthalmitis
Clinical Features
- White or yellow-white layering fluid visible at the dependent (inferior) portion of the anterior chamber
- Best visualized on slit-lamp exam
- Associated findings depend on etiology:
Differential Diagnosis
- Corneal ulcer (infectious keratitis) — most common cause; look for corneal infiltrate/opacity
- Endophthalmitis — post-surgical or post-traumatic; vitreous involvement
- Uveitis (anterior) — may be idiopathic or associated with systemic disease
- Traumatic iritis (severe)
- Behcet's disease — recurrent hypopyon with oral/genital ulcers
- Intraocular tumor (rare)
Evaluation
- Visual acuity
- Slit-lamp exam: quantify hypopyon height (mm), assess cornea for ulcer/infiltrate, anterior chamber cells/flare
- Fluorescein staining: rule out corneal ulcer
- IOP measurement (may be elevated or low)
- Dilated fundoscopic exam if endophthalmitis suspected (vitreous haze)
- If corneal ulcer: Obtain corneal scrapings for culture before starting antibiotics (ophthalmology)
Management
- Emergent ophthalmology consult for all cases
- Do not start treatment until ophthalmology evaluates (may need cultures first)
- Treatment depends on underlying cause:
- Infectious keratitis: Fortified topical antibiotics (ophthalmology-directed)
- Uveitis: Topical steroids + cycloplegic (ophthalmology-directed)
- Endophthalmitis: Intravitreal antibiotics ± vitrectomy
Disposition
- Emergent ophthalmology consult from ED
- Most cases require close daily ophthalmology follow-up or admission