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



The primary purpose of this study is to determine if patients randomized to corneal collagen cross-linking plus medical therapy will have a lower prevalence of positive bacterial or fungal cultures immediately after the procedure than patients who received medical therapy alone. The secondary purpose of this study is to determine if patients randomized to corneal collagen cross-linking will have a better visual acuity at 3 and 12 months than patients who receive medical therapy alone.


The proposed study is a randomized controlled trial to determine whether collagen cross-linking improves outcomes in microbial keratitis. Patients presenting to the Aravind Eye Hospitals in Madurai, India for treatment of microbial keratitis will be recruited for the proposed study. Approximately 266 patients will be enrolled in the study. Subjects presenting with bacterial keratitis will be randomized to receive medical therapy plus corneal collagen cross-linking at presentation or to receive medical therapy alone. All subjects with bacterial ulcers will receive standard topical antibiotic medications as required after the procedure. Subjects with fungal keratitis will be randomized into one of four groups: 1. collagen cross-linking + amphotericin; 2. collagen cross-linking + natamycin; 3. amphotericin alone; 4. natamycin alone. All study subjects will be followed for 12 months to evaluate response to treatment. Investigators from the University of California, San Francisco (UCSF) will assist Aravind Eye Hospital with the study design, implementation, and analysis of the research, and will help fund the study. The investigators plan to visit Aravind to help with the study implementation. UCSF will play an important role in this study by assisting with the study design, implementation, analysis, and funding.


Corneal Ulcer Infectious Keratitis Bacterial Ulcer Fungal Ulcer Cornea Ulcer Bacterial Fungal Communicable Diseases Infection Keratitis Bacterial ulcer cross-linking Fungal ulcer cross-linking Fungal ulcer cross-linking plus natamycin Fungal ulcer cross-linking plus amphotericin


You can join if…

Open to people ages 18 years and up

  • Corneal ulcer that is smear positive for either bacteria or filamentous fungus
  • Pinhole visual acuity worse than 20/70 in the affected eye
  • Not treated already with antimicrobial medications at presentation
  • 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 or gram stain (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 or recent intraocular surgery
  • No light perception in the affected eye
  • Pinhole visual acuity worse than 20/200 in the unaffected eye
  • Participants who are decisionally and/or cognitively impaired


  • Proctor Foundation, UCSF in progress, not accepting new patients
    San Francisco California 94143 United States
  • Aravind Eye Hospitals accepting new patients
    Madurai Tamil Nadu India

Lead Scientist at UCSF

  • Jeremy Keenan
    Professor, Proctor Foundation. Authored (or co-authored) 240 research publications.


accepting new patients
Start Date
Completion Date
University of California, San Francisco
Phase 4
Study Type
Last Updated