To study the effect of collagen cross-linking (CXL) as a primary treatment for bacterial keratitis in two ophthalmological centres, through a non-randomised clinical pilot study of twenty patients
Bacterial keratitis is a sight threatening condition with a relatively large risk for visual impairment. Bacterial strains are becoming increasingly resistant to all known antibiotics. In CXL a photo-activation of riboflavin is used, which is also used in Pathogen Inactivation Therapy in transfusion medicine. Several groups have presented treated ulcers and cases of infectious keratitis successfully treated with CXL. Based on these experiences a protocol to study CXL as a primary treatment for bacterial keratitis has been created.
That CXL can be used as primary therapy for bacterial keratitis.
Regional Ethical Committee in Uppsala, Sweden, approved on the 6th October 2008 (ref: 2008/250). An amendment was approved on the 5th June 2009.
Prospective non-randomised clinical pilot study
Primary study design
Secondary study design
Non randomised controlled trial
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet
Please note that as of 03/08/10 the status of this trial was changed to completed. The previously anticipated end date was 31/12/10. The decision was made to end the trial after the inclusion of 16 patients as study coordinators see this number as sufficient to answer the hypothesis.
Microbial culturing is conducted. CXL is performed with settings for keratoconus after pachymetry. Post-operatively the patient is examined one to several times daily until healing has taken place. Slit-lamp photography is done at each examination. The patient is excluded from the study if signs of infectious progress are seen and if the results from microbial culturing are negative. Healing of the keratitis at two consecutive visits is defined as the primary end-point. The patient is followed until no symptoms are present and complete healing of the ulcer has been observed.
Primary outcome measure
Healing of the epithelium and arrest of corneal melting at two consecutive visits.
Secondary outcome measures
Any side effects and complications of treatment.
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
To be included in the study all patients must fulfil the following criteria:
1. Suspected bacterial keratitis
2. Aged 18 years or above, either sex
3. Signed informed consent
Target number of participants
20 (final recruitment: 16)
Participant exclusion criteria
1. Any antibiotic treatment for the current episode of keratitis
2. Suspicion of a non-bacterial keratitis
3. Pachymetry values under 400 mm
4. Pregnancy or breast-feeding
5. Allergy towards riboflavin or any substance in Ricrolin®
6. Participation in any ophthalmological study in which the follow-up is not completed
7. The patient might not be able to complete the follow-up after treatment required in the study
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Department of Ophthalmology
Örebro University Hospital (Sweden) - Ophthalmological research funds (D-number: OLL-57221)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
1. 2012 results in http://www.ncbi.nlm.nih.gov/pubmed/21874347
Makdoumi K, Mortensen J, Sorkhabi O, Malmvall BE, Crafoord S, UVA-riboflavin photochemical therapy of bacterial keratitis: a pilot study., Graefes Arch. Clin. Exp. Ophthalmol., 2012, 250, 1, 95-102, doi: 10.1007/s00417-011-1754-1.