Steroids and Cross-linking for Ulcer Treatment

Topical moxifloxacin 0.5% is a fluoroquinolone antibiotic that is used to treat bacterial infections. This is standard therapy for bacterial keratitis. Immediately after CXL/sham CXL and repeat culture, all participants will receive topical moxifloxacin drops every 1 hour for 2 days, and then every 2 hours while awake until resolution of the epithelial defect.

Difluprednate 0.05% is a corticosteroid used to reduce inflammation in the eye. Participants will receive one drop of 0.05% difluprednate four times daily beginning 24 hours after the initiation of antibiotics for 1 week, decreased by 1 drop weekly for a total of 4 weeks of steroid therapy.

All participants will receive a 30 minute loading dose of topical 0.1% riboflavin and 20% dextran T500 drops every 2 minutes. For participants randomized to corneal cross-linking(CXL), this will be followed by exposure to UV-A light at a wavelength of 365 nm with an irradiance of 3 mW/cm2 for 30 minutes for a total dose of 5.4 J/cm2 (UV lamp: PESCHKE Meditrade GmbH, Hueneberg, Switzerland for India; Avedro KXL System, Waltham, MA, USA for USA). During irradiation patients will continue to receive topical riboflavin at 5-minute intervals. For those randomized to sham CXL, this experience is simulated however the light will be shined adjacent to the patient, careful to avoid exposure to the cornea.

Participants randomized to topical placebo will receive topical placebo on the same medication schedule as difluprednate: one drop of 0.05% difluprednate four times daily beginning 24 hours after the initiation of antibiotics for 1 week, decreased by 1 drop weekly for a total of 4 weeks of placebo therapy. Placebo will be the vehicle used in difluprednate.