Rose Bengal Electromagnetic Activation With Green Light for Infection Reduction (REAGIR)

Aravind Eye Care System, National Eye Institute (NEI), Stanford University, Federal University of São Paulo

Rose Bengal Electromagnetic Activation with Green light for Infection Reduction (REAGIR ) is an international, randomized, doubled masked, clinical trial. The purpose of this study is to determine differences in 6-month visual acuity between medical antimicrobial treatments alone versus antimicrobial treatment plus cross-linking with rose Bengal (RB-PDT). Patients presenting to one of the Aravind Eye Hospitals in India or to the Federal University of São Paulo ophthalmology clinic in Brazil with either smear or culture positive fungal or acanthamoeba keratitis or smear and culture negative corneal ulcers and moderate to severe vision loss, defined as Snellen visual acuity of 20/40 or worse, will be eligible for inclusion. Those who agree to participate will be randomized to one of two treatment groups: Group 4, Sham RB-PDT: topical chlorhexidine gluconate 0.02% (acanthamoeba), moxifloxacin 0.5% (smear/culture negative) or natamycin 5% (fungal keratitis) plus sham RB-PDT Group 5, RB-PDT: topical chlorhexidine gluconate 0.02% (acanthamoeba), moxifloxacin 0.5% (smear/culture negative) or natamycin 5% (fungal keratitis) plus RB-PDT.

Patients in this arm will receive topical chlorhexidine gluconate 0.02% (acanthamoeba), moxifloxacin 0.5% (smear/culture negative) or natamycin 5% (fungal keratitis) plus sham RB-PDT

Patients in this arm will receive topical chlorhexidine gluconate 0.02% (acanthamoeba), moxifloxacin 0.5% (smear/culture negative) or natamycin 5% (fungal keratitis) plus RB-PDT

Topical moxifloxacin 0.5% is a fluoroquinolone antibiotic that is used to treat bacterial infections. This is a standard therapy for bacterial keratitis.

Topical chlorhexidine gluconate 0.02% is an antiseptic agent, with both antibacterial and antifungal properties. This is a standard therapy for Acanthamoeba keratitis.

Natamycin 5% is an antifungal agent used to treat fungi that cause keratitis. This is a standard therapy for fungal keratitis.

Study participants receive RB-PDT within 48 hours of randomization. All participants will receive a 30-minute loading dose of topical Rose Bengal (0.1% RB in 0.9% sodium chloride) which will be applied in 5-minute intervals to the de-epithelialized cornea. This will be followed by irradiation with a 6mW/cm2 custom-made green LED source for 15 minutes (5.4J/cm2). Repeat cornea culture will be collected within 24 hours after the procedure.

Study participants receive sham RB-PDT within 48 hours of randomization. Participants will receive a 30-minute loading dose of topical balanced salt solution which will be applied in 5-minute intervals to the de-epithelialized cornea. A pen light covered with a green filter will be used for 15 minutes. Repeat cornea culture will be collected 30 minutes after the sham procedure.

Inclusion Criteria: Presence of smear or culture positive fungal or acanthamoeba ulcer; smear or culture negative ulcer; or any atypical bacteria (such as Nocardia) Moderate to severe vision loss, defined as Snellen visual acuity of 20/40 (6/12) or worse Corneal thickness ≥350 µm, as measured on AS-OCT Age over 18 years Basic understanding of the study as determined by the physician Commitment to return for follow up visits Exclusion Criteria: Evidence of concomitant infection on exam, gram stain, or confocal microscopy (i.e. herpes, both bacteria and acanthamoeba on gram stain) Impending or frank perforation at recruitment Involvement of sclera at presentation Non-infectious or autoimmune keratitis History of corneal transplantation History of intraocular surgery within last three months Pinhole visual acuity worse than 20/200 in the unaffected eye Participants who are decisionally and/or cognitively impaired Presence of demestocele at recruitment