Safety and Effectiveness of the PXL Platinum 330 System With Riboflavin Solution for Refractory Corneal Ulcers

This is a prospective, 2-arm parallel-group, single-blind, randomized multicenter study to determine the safety and effectiveness of the PXL Platinum 330 System for performing CXL in eyes with refractory corneal ulcers. Subjects with a history of non-resolving infective corneal ulcers will be evaluated initially for suitability as a candidate for CXL. Subjects who are candidates for CXL will be asked to participate in this study and will undergo the required screening procedures to determine study eligibility. Informed consent will be obtained from each subject before performance of any required study procedures that are not part of the investigator's routine examination. After completing screening procedures, the diagnosis for each eligible eye will be confirmed. Subjects will be randomized to 1 of 2 groups:

1. Group 1: Standard-of-care therapy (anti fungal drops if there is clinical suspicion for fungus, fortified antibiotics if corneal culture is positive for a specific organism sensitive to a fortified antibiotic, and empiric antibiotic drops based on community prevalence if corneal culture is negative and there is no clinical suspicion for fungus)

2. Group 2: Standard-of-care therapy + CXL

Eyes undergoing CXL will have topical anesthetic administered and then have topical riboflavin instilled onto the cornea every 2 min (or longer as needed to assure adequate corneal penetration), after which the cornea will be exposed to UV-A pulsed light 18 mW/cm2 for 10 min. Riboflavin instillation will continue every 2 min during CXL. The CXL procedures will be performed on an outpatient basis using the PXL Platinum 330 System (UV-A light source and riboflavin solution). All use of the PXL Platinum 330 System will be in accordance with this protocol and the general instructions provided by the manufacturer (PESCHKE) in the PXL Platinum 330 Illumination System Operator's Manual. All subjects will be evaluated at Screening/Baseline, Day 0 (Randomization/Treatment), Day 1, Day 3 ( +/- 1 day), Week 1 ( +/- 2 days), Week 2 ( +/- 2 days), Week 4 ( +/- 3 days), and Week 6 ( +/- 4 days) after treatment. Efficacy monitoring throughout the study will include observations at appropriate times for re-epithelialization, size of infection, and corneal culture results. Safety monitoring throughout the study will include observations at appropriate times for pain, IOP, BSCVA, corneal scar size, AEs, clinically significant findings on ophthalmic examination, dilated fundus examination, and slit lamp examination. After treatment, subjects will be followed at the treating physician's discretion.