for people ages 18 years and up (full criteria)
at San Francisco, California and other locations
study started
estimated completion
Principal Investigator
by Tom Lietman, MD
Photo of Tom Lietman
Tom Lietman



Steroids and Cross-linking for Ulcer Treatment (SCUT II) is an international, randomized, double-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 collagen cross-linking (CXL), as well as to further evaluate findings from subgroup analyses of SCUT. Patients presenting to the Aravind Eye Care System (India), Kaiser Permanente Northern California (USA), or the University of California, San Francisco (USA) 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 or worse, will be eligible for inclusion. Those who agree to participate will be randomized to one of three treatment groups: Group 1: Standard therapy, topical 0.5% moxifloxacin plus topical placebo plus sham CXL Group 2: Early steroids, topical 0.5% moxifloxacin plus topical difluprednate 0.05% plus sham CXL Group 3: CXL plus early steroids, topical 0.5% moxifloxacin plus topical difluprednate 0.05% plus CXL


Keratitis Bacterial Keratitis Riboflavin Moxifloxacin Difluprednate Moxifloxacin Ophthalmic Difluprednate Ophthalmic Riboflavin Ophthalmic Early Steroids Cross-Linking plus Early Steroids


You can join if…

Open to people ages 18 years and up

  • Corneal ulcer that is smear positive and/or culture positive (within 24 hours) for typical bacteria (i.e. non-Nocardia or Mycobacteria)
  • 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

You CAN'T join if...

  • Evidence of concomitant infection on exam, gram stain, or confocal microscopy (i.e. herpes, both bacteria and acanthameoba on gram stain)
  • Impending or frank perforation at recruitment
  • Involvement of sclera at presentation
  • Non-infectious or autoimmune keratitis
  • History of corneal transplantation or recent intraocular surgery
  • Pinhole visual acuity worse than 20/200 in the unaffected eye
  • Participants who are decisionally and/or cognitively impaired


  • Francis I. Proctor Foundaiton not yet accepting patients
    San Francisco California 94143 United States
  • Kaiser Permanente Northern California not yet accepting patients
    Redwood City California 94063 United States

Lead Scientist at UCSF

  • Tom Lietman, MD
    Professor, Proctor Foundation. Authored (or co-authored) 392 research publications.


accepting new patients
Start Date
Completion Date
Thomas M. Lietman
Phase 3
Study Type
Last Updated