Trichoderma longibrachiatum keratitis following corneal collagen cross-linking for keratoconus: a case report and review of literature

To report a rare case of microbiologically proven Trichoderma longibrachiatum keratitis following corneal collagen cross-linking (CXL) and review the published literature on ocular infections caused by Trichoderma species. A 27-year-old immunocompetent male developed fungal keratitis one month after undergoing CXL for keratoconus. The corneal scraping and culture were positive for T. longibrachiatum. Sensitivity testing for antifungals showed susceptibility to natamycin (dose dependent) and voriconazole and resistance to amphotericin B, caspofungin, posaconazole and ketoconazole. Topical 5% natamycin hourly treatment led to a favourable clinical response with improvement in visual acuity from hand movements to 20/160 at 16-day follow-up. Clinical, microbiological and antifungal susceptibility data from an observational case report. We reviewed the published literature on Trichoderma keratitis and ocular infections. T. longibrachiatum is an uncommon but emerging cause of fungal keratitis with unique antifungal resistance profiles including resistance to amphotericin B. The use of topical corticosteroid after CXL with epithelial disruption is a possible contributory risk factor. Natamycin is still a suitable first-line agent. Clinicians should be aware of rare infections with environmental moulds after corneal procedures, especially in patients with long epithelial defects.