Evaluation of the Efficacy of Intrastromal Antifungal Injection and Prognostic Factors Affecting Treatment Success in Fungal Keratitis

Purpose To assess the clinical outcomes of intrastromal antifungal (ISAF) injection in fungal keratitis and to identify the etiologic and prognostic factors that differentiate responsive from refractory cases.Methods Patients with fungal keratitis treated in a tertiary cornea unit between January 2023 and January 2026 who received ISAF injection after an inadequate response to fortified topical therapy were reviewed retrospectively. Intrastromal voriconazole (50 µg/0.1 mL) was given first; amphotericin B (5 µg/0.1 mL) was added only in eyes that continued to progress. Healing was defined biomicroscopically as epithelial closure, resolution of hypopyon and resolution of the infiltrate.Results Twenty-nine patients (mean age 54.3 ± 22.3 years) were included. Previous ocular surface surgery (n = 13) and trauma (n = 7) predominated; Candida (34.5%) and Fusarium (24.1%) were isolated most often. Twenty eyes (69.0%) responded to ISAF and nine (31.0%) were refractory; mean healing time was 38.8 ± 19.2 days. Cross-linking was performed in five refractory eyes, two of which healed; seven eyes required therapeutic keratoplasty. A longer symptom-to-presentation interval (22.8 vs 6.3 days, p = 0.013) and a lesion larger than 6 mm (p < 0.001) were associated with treatment failure.Conclusion Clinical resolution followed ISAF injection in most refractory eyes, but without a control arm its separate contribution cannot be established. Delayed presentation, larger lesion size and central location were associated with an unfavorable outcome.