Treatment of Corneal Ulcer with Hypopyon
A corneal ulcer with hypopyon requires immediate aggressive treatment with broad-spectrum topical antibiotics after obtaining corneal cultures and smears, as this represents sight-threatening bacterial keratitis. 1
Immediate Diagnostic Workup
Cultures and smears are mandatory before initiating treatment when hypopyon is present, as this indicates severe infection. 1 The 2024 American Academy of Ophthalmology guidelines specifically state that smears and cultures are recommended when there are ≥1+ cells in the anterior chamber. 1
Obtain the following:
- Corneal scrapings from the ulcer base and periphery using a sterile blade or spatula under slit-lamp visualization 1
- Gram stain and Giemsa stain for immediate pathogen identification 1
- Culture media inoculation directly onto blood agar, chocolate agar, and thioglycolate broth 1
- Consider specialized stains (potassium hydroxide, calcofluor white, acid-fast) if atypical features suggest fungal, amoebic, or mycobacterial infection 1
Important caveat: The hypopyon itself is usually sterile and should NOT be tapped unless there is high suspicion for endophthalmitis (post-surgical, perforating trauma, or sepsis). 1
Initial Antibiotic Therapy
Start intensive broad-spectrum topical antibiotics immediately after obtaining cultures. 1
Recommended regimens:
Option 1: Fluoroquinolone monotherapy
- Moxifloxacin 0.5% or gatifloxacin 0.5% (preferred for gram-positive coverage) 2, 3
- Loading dose: Every 5-15 minutes for the first 30-60 minutes 3
- Maintenance: Every 30-60 minutes around the clock initially 3
Option 2: Fortified antibiotic combination (traditional approach)
- Fortified tobramycin 1.5% (or gentamicin 1.4%) PLUS fortified cefazolin 5-10% 3, 4
- Same intensive dosing schedule as above 3
The evidence shows fluoroquinolone monotherapy is as effective as fortified combination therapy for bacterial keratitis, though fortified antibiotics may be preferred for severe cases or known resistant organisms. 2
Adjunctive measures:
- Cycloplegic agent (atropine 1% or homatropine 5%) three times daily to reduce pain and prevent posterior synechiae 3
- Avoid topical corticosteroids in the acute phase, as they can worsen infection 3
Monitoring and Modification
Reassess at 24-48 hours for clinical response. 1
Signs of improvement include:
- Reduced pain and discharge 1
- Consolidation and sharper demarcation of infiltrate borders 1
- Decreased stromal infiltrate density without progressive stromal loss 1
- Reduced anterior chamber cells, fibrin, or hypopyon 1
- Initial re-epithelialization 1
Modify therapy if no improvement or worsening at 48 hours, adjusting based on culture results and sensitivities. 1 Pseudomonas and gram-negative organisms may show increased inflammation in the first 24-48 hours despite appropriate therapy. 1
Tapering:
- Do not taper below 3-4 times daily, as lower doses are subtherapeutic and promote resistance 1
- Taper gradually based on clinical response, considering initial severity and pathogen virulence 1
Critical Pitfalls to Avoid
Fluoroquinolone resistance is increasing, particularly in patients with recent fluoroquinolone use, hospitalization, advanced age, or recent ocular surgery. 2 If the patient has these risk factors, strongly consider fortified antibiotics initially. 2
Do not patch the eye or use bandage contact lenses in the acute phase, as this increases risk of worsening infection. 2, 5, 3
Medication toxicity can mimic treatment failure, causing persistent epithelial defects or corneal melting despite infection control. 1 If the infection appears controlled but inflammation persists, consider drug toxicity. 1
Atypical organisms require special consideration: If the ulcer fails to respond to standard therapy, consider tuberculosis (especially if Mantoux or interferon-gamma release assay positive) 6, fungal infection (particularly with history of vegetable matter trauma) 7, or extensively drug-resistant organisms. 8 Reculture with specialized media may be needed. 1