Fusarium falciforme keratitis in a corneal transplant recipient treated successfully with fosmanogepix and intracameral amphotericin B

Background Ocular fungal infections are a major cause of vision loss worldwide. Fusarium spp., a leading cause of fungal keratitis, is often difficult to treat. There are no current standardized treatment guidelines for fungal keratitis. We present a case of Fusarium spp. keratitis that was treated with fosmanogepix and intracameral amphotericin B, highlighting additional treatment options in difficult-to-treat cases. To our knowledge, this is the first report of fosmanogepix use in Fusarium keratitis. Case Summary A 72-year-old man presented with 2 weeks of right eye pain and redness and was diagnosed with Fusarium falciforme keratitis via ocular fungal culture. He failed multiple topical, oral, and intraocular antifungal agents, and required corneal transplantation. Histopathology from his explant showed hyaline hyphae with occasional sickle-shaped conidia, consistent with Fusarium spp. The infection recurred in the corneal allograft despite intravitreal voriconazole, intraocular amphotericin B, and topical natamycin. Ultimately, he underwent successful treatment with fosmanogepix, a first-in-class antifungal agent. Conclusion Our case illustrates the challenges of managing Fusarium keratitis and the potential role of novel antifungal agents, such as fosmanogepix, as adjuncts to established intraocular and topical therapy in the setting of clinical failure.