Fungal Ulcer Treatment Augmented with Natamycin and Cyclosporine (FANCY): study protocol for a randomized, double-masked, parallel-arm clinical trial comparing 0.1% cyclosporine A, 2% cyclosporine A, and placebo as adjunctive therapy to natamycin for

Abstract Background Fungal keratitis is a vision threatening disease which leads to loss of the affected eye in 8–11% of cases. Topical antifungal agents are typically first line therapy. Cyclosporine A (CsA) has been shown to inhibit the growth of certain pathogenic filamentous fungi in vitro . This randomized controlled trial aims to determine the effectiveness of topical CsA as an adjunct to the standard anti-fungal therapeutic regimen. Methods A three-armed, parallel, randomized, masked, placebo-controlled clinical trial is presented. Participants with smear- or culture- confirmed fungal keratitis and mild to moderate disease, defined as best spectacle corrected visual acuity between LogMAR 0.2 and 1.3. In addition to standard topical anti-fungal therapy, patients will be randomized to one of three arms to receive topical CsA 2%, topical CsA 0.1%, or placebo. Best spectacle corrected visual acuity at 12 weeks will serve as the primary outcome. Discussion There is limited literature on the role of CsA in fungal keratitis. This study will provide insight into the use of adjunctive nonsteroidal anti-inflammatory therapies for this potentially sight-threatening disease. Trial Registration This trial was registered on Clinical Trials.org on October 23, 2024. (NCT06658002, https://clinicaltrials.gov/study/NCT06658002)