RB-PDT for Fusarium Keratitis: The LUMIERE Study

Participants with fusarium corneal ulcers will be randomized in a 1:1 fashion to one of two arms: * Group 1, RB-PDT: natamycin 5%/Amphotericin B 0.15% plus RB-PDT * Group 2, Sham RB-PDT: natamycin 5%/Amphotericin B 0.15% plus sham RB-PDT Participants will begin topical antimicrobial upon initial diagnosis: applied to the affected eye every hour while awake for the first week, then every 2 hours while awake for 3 weeks. Thereafter, application will be tapered at the discretion of the treating physician based on response to therapy. RB-PDT/sham RB-PDT will occur within 5 days of initial smear/culture. For Group 1, Rose Bengal (0.1% RB in 0.9% sodium chloride) will be applied in 3-minute intervals to the de-epithelialized cornea for 30 minutes followed by irradiation with a 6mW/cm2 custom-made green LED source for 15 minutes (5.4J/cm2). Participants in Group 2 will undergo a sham procedure using topical balanced salt solution and pen light covered with a green filter. Study participants will undergo repeat scraping and culture of the corneal ulcer 30 minutes after the assigned RB-PDT procedure. A second RB-PDT/sham RB-PDT procedure and repeat smear/culture will occur one week after the first procedure, following the same protocol.