Fungal Keratitis: What to Do When Initial Topical Antifungal Treatment Has Not Improved or Stabilized the Infection
This protocol applies when a patient with fungal keratitis has already received first-line topical antifungal therapy and has not achieved the expected clinical improvement or stabilization of the corneal infection.
The preceding line of care relied on topical antifungal agents as the mainstay — including natamycin, amphotericin B, econazole, clotrimazole, or topical fluconazole — alongside supportive measures. Escalation to this protocol is triggered by the failure to achieve clinical improvement or stabilization of the corneal infection with that approach.
Management at this stage involves augmenting the topical antifungal regimen with an additional agent, combined with a procedural intervention to reduce microbial load and improve drug penetration into the cornea. In more severe or extensive presentations, systemic antifungal therapy and additional supportive agents may also be incorporated.
References
- Voriconazole (1 mg/mL) q1h, then tapered over 4-6 wks
- Used as an adjunct to natamycin in deeper and larger ulcers
- Epithelial debridement may help remove necrotic tissue, decrease microbial load, and improve drug penetration
- May be repeated q 24-48 hours
- Systemic antifungals (p.o. fluconazole or voriconazole or ketoconazole) may be a useful adjunct, especially in severe cases (deep ulcer, scleral involvement, endophthalmitis)
- Systemic ascorbic acid may be useful to accelerate corneal remodeling and healing by inhibiting polymorphonuclear cells.