When to prioritize antimicrobial therapy (AMT) over tissue glue in cases of keratitis with corneal perforation and suspected infection?

When to Prioritize AMT Over Tissue Glue in Keratitis

Prioritize amniotic membrane transplantation (AMT) over tissue glue alone when perforation size exceeds 3 mm, when the defect has a ballooning descemetocele rather than a crater base, when the wound cannot be adequately dried, or when you need to stabilize progressive corneal melting with active infection that requires continued aggressive antimicrobial therapy. 1, 2

Decision Algorithm for AMT vs Tissue Glue

Choose Tissue Glue Alone When ALL Criteria Met:

• Perforation ≤3 mm in diameter 1
• Defect located at bottom of a crater (not a ballooning descemetocele) 1
• Clean, compact, dry base that allows proper adhesion 1
• Infection is resolving and under control with antimicrobials 1, 3

Choose AMT When ANY of These Present:

• Corneal stromal thinning without frank perforation - AMT decreases inflammation and stabilizes the ocular surface to avoid urgent keratoplasty 4, 2
• Progressive corneal melting despite antimicrobial therapy 2
• Small perforations where you want to seal AND promote healing rather than just mechanical closure 2
• Cases refractory to medical treatment where you need to improve prognosis of subsequent elective keratoplasty 4, 2

Critical Technical Contraindications to Glue Alone

Tissue adhesive fails when:

• Perforation >3 mm - requires Tenon's patch graft with cyanoacrylate or AMT 1, 3
• Ballooning descemetocele present - adhesive works poorly on convex surfaces 1
• Base cannot be adequately dried - moisture prevents proper adhesion 1
• Central or paracentral location with active infection - glue serves only as temporizing measure, not definitive treatment 1

Evidence-Based Outcomes Supporting AMT Priority

AMT provides superior outcomes in infected keratitis:

• Double-layer AMT applied 2-5 days after antibiotic initiation improved visual acuity at 6 months in randomized controlled trial 4
• Single-layer AMT in Pseudomonas keratitis decreased pain, decreased corneal opacity density, and improved uncorrected visual acuity compared to antibiotics alone 4
• Tissue glue alone healed only 44% of perforations in historical series, with 11% complication rate including culture-proven bacterial infections occurring average 73 days post-gluing 5

Timing Considerations

Apply AMT early (2-5 days after antimicrobial initiation) rather than waiting for complete infection resolution, as this improves visual outcomes and prevents urgent keratoplasty 4, 2. In contrast, tissue glue should only be applied after infection is resolving, as active infection increases risk of secondary bacterial infiltrates under the glue 1, 5, 3.

When to Combine Both Approaches

For larger perforations (>3 mm) in resolving keratitis, use Tenon's patch graft with cyanoacrylate glue - this achieved 93% successful tectonic restoration in recent series of infective keratitis perforations 4, 3. This combination provides both mechanical support and infection control when AMT alone may be insufficient 4.

Common Pitfall to Avoid

Never use fibrin glue for corneal perforations or descemetoceles - it biodegrades too rapidly before healing occurs 1. Only cyanoacrylate tissue adhesive provides adequate duration (6+ weeks) for corneal healing 1.