Intra-operative photograph demonstrating the ultraviolet light source irradiating the cornea, which has been soaked with riboflavin Photo: Clinical and Experimental Optometry, 2013; 96: 2: 155-164.
Corneal collagen cross-linking (CXL) is effective at stabilising keratoconus in most cases, three-year results from a five-year prospective randomised controlled trial of CXL for progressive keratoconus show.
Initial results of the trial also showed that in some cases, the procedure improves vision with and without spectacles.
At 36 months, there was a sustained improvement in the maximum simulated keratometry value, uncorrected visual acuity and best spectacle-corrected visual acuity after CXL, whereas eyes in the control group demonstrated further progression of the disease.
Centre for Eye Research Australia researchers reported results on 48 control and 46 treated eyes three years after being allocated to treatment groups. They published these results in Ophthalmology online on 6 January and in the journal’s April 2014 issue.
CXL involves applying riboflavin (vitamin B2) solution to the cornea and activating the riboflavin with ultraviolet A irradiation. The process strengthens the cornea and can slow or halt progression of keratoconus.
Investigator Dr Christine Witting-Silva said CERA was now focusing on completing the study over the next two years. ‘We couldn’t have come this far without our participants and donors and we are very grateful for their time and support,’ she said.
Keratoconus is usually diagnosed in the teenage years and remains the most common reason for corneal transplantation in Australia.
Since the first clinical study in Germany in 2003, studies have reported the safety and effectiveness of the procedure but there has been a lack of randomised controlled studies comparing treated eyes with untreated eyes and providing longer-term follow-up to support widespread use of the treatment.
Adverse events have also been reported in some studies.
Witting-Silva C, Chan E, Islam FM, Wu T, Whiting M, Snibson GR. A randomized, controlled trial of corneal collagen cross-linking in progressive keratoconus: three-year results. Ophthalmology 2014; 121: 812-21.