Successful Salvage Treatment of Scedosporium apiospermum Keratitis with Topical Voriconazole After Failure of Natamycin

Abstract

To report successful management of Scedosporium apiospermum (previously known as Monosporium apiospermum) keratitis with topical voriconazole as monotherapy. A 54-year-old previously well woman presented to the emergency department with a painful, injected right eye. There was no history of trauma or use of contact lenses. On examination, the right eye was estimated to have visual acuity of hand movement. Slit lamp examination detected a 2.5 x 3.5 mm dense, central corneal infiltrate with overlying epithelial defect. The eye had mild corneal edema with anterior chamber inflammation. Microbiology testing revealed S. apiospermum as the primary pathogen. Hourly administration of topical natamycin 5% resulted in initial improvement in visual acuity to 20/50, with reduction in the size of the central infiltrate. However, 1 month later, the eye infection relapsed, with recurrence of epithelial defect (3.1 x 3.1 mm) and decline in visual acuity to 20/100. Antifungal therapy was switched to topical voriconazole 1%, administered every 2 hours. Vision improved to 20/30 within 5 days, and the central defect had completely re-epithelialized within 1 week. Treatment of S. apiospermum keratitis remains inadequate. A high natamycin minimum inhibitory concentration is necessary to treat S. apiospermum infection, which may explain the persistence of central infiltration despite ongoing therapy. The combined use of topical and oral voriconazole for the treatment of S. apiospermum keratitis has been reported. However, this is the first report of a successful clinical experience using topical voriconazole without oral therapy to manage S. apiospermum keratitis. This eliminates some disadvantages associated with oral voriconazole such as high cost, potential significant toxicity, and drug interactions. The voriconazole 1% eye drop used alone is a promising, cost-effective, safe option for managing fungal keratitis, even that caused by S. apiospermum. It may have a larger role to play than simply that of adjunctive therapy.