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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
147
For those subjects randomized to receive collagen cross-linking, the procedure will be performed as per the routine at the hospital (UV-X machine; strict aseptic precautions; corneal epithelium debrided and 0.1% riboflavin applied for 30 minutes, then UV-A radiation applied for 30 minutes at 370nm with 3mW/cm2). Corneal cross-linking is a routine procedure performed by Aravind Eye Hospital for infectious keratitis.
Topical Amphotericin B vs Topical Natamycin
Proctor Foundation, UCSF
San Francisco, California, United States
Aravind Eye Hospitals
Madurai, Tamil Nadu, India
Microbiological Cure on Repeat Culture
Corneal scraping of the ulcer will be performed and directly inoculated on to sheep's blood agar, chocolate agar, potato dextrose agar or Sabouraud's agar for bacterial and fungal culture. Microbiological cure is defined as no growth of bacteria or fungus on these media.
Time frame: 4 to 24 hours after enrollment
Best Spectacle-corrected Visual Acuity
Best corrected visual acuity will be measured at baseline for both eyes using the standard ETDRS chart light box at the 4- and 1-meter test distances. In the case that the patient reads less than 10 letters at 4 meters, move the patient or the chart to a distance of 1 meter from the patient.
Time frame: 3 months
Scar Size
Study clinician will measure infiltrate or scar size using a standardized protocol with the slit lamp biomicroscope. The geometric mean of the scar size will be measured by recording the horizontal and vertical diameter.
Time frame: 3 months
Adverse Events Including Rate of Perforation/Need for Therapeutic Penetrating Keratoplasty
Adverse events include glaucoma, endophthalmitis, medication reaction, perforation including treatment by therapeutic penetrating keratoplasty.
Time frame: 3 months
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