Rose Bengal Electromagnetic Activation With Green Light for Infection Reduction II

Rose Bengal Electromagnetic Activation with Green light for Infection Reduction II (REAGIR II) is a randomized, double-masked feasibility study. 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 smear-positive and/or culture positive typical (I.e. non-Nocardia or Mycobacteria) bacterial corneal ulcers and moderate to severe vision loss, defined as Snellen visual acuity of 20/40 of worse, will be eligible for inclusion. Those who agree to participate will be randomized to one of two treatment groups: * Group 6, RB-PDT Plus Early Steroids: topical 0.5% moxifloxacin plus topical difluprednate 0.05% plus RB-PDT * Group 7, Sham RB-PDT Plus Early Steroids: topical 0.5% moxifloxacin plus topical difluprednate 0.05% plus sham RB-PDT