Purchase this article with an account.
Vincent Imbrogno, Matthew Pihlblad; Treatment of Keratoconus Using Collagen Cross Linking. Invest. Ophthalmol. Vis. Sci. 2012;53(14):6809.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Keratoconus is a bilateral, non-inflammatory condition of the cornea that leads to thinning of the cornea and protrusion of the anterior portion of the cornea. Current treatment regimens include, spectacles, contact lenses, Intracorneal ring segments, and penetrating or lamellar keratoplasty. Currently, there is no approved medical therapy in the United States for this disease. The method of using riboflavin combined with UV light to induce collagen cross-linking has been well studied in other parts of the world, and such a regimen is used as first-line therapy in Europe and Canada. The purpose of our study is to investigate for potentially reproducible results from these studies, with intent to pursue approval of this technique in the United States.
Prospective, randomized, double-blinded, sham-procedure controlled study. Patients would be randomly assigned to one of two arms of the study: application of 0.1% riboflavin on a de-epithelized cornea and then subjected to focal UV light (370nm) for 30 minutes, or sham procedure. Patients were then followed at 1, 3, 6, 12, 18, and 24 months, with ancillary tests such as corneal topography, hysteresis, pachometry, and full eye exam at each visit.
22 patients received treatment, while 16 patients received the sham procedure. Average time to follow-up was 16 months (range 3-24 months). Only those patients whom had at least 6 months follow-up were included in statistical analysis. Differences between pre-treatment measurements and those of the most recent follow-up visit were calculated. Differences were averaged for the treatment and control groups. Statistical significance was determined via Wilcoxon p-value test.In comparison of treatment and control groups, there was a statistically significant reduction in spherical aberration (-0.321 vs. +.0.45, p=0.048). Additionally, there was a statistically significant reduction in total aberration in the treatment group (-0.591 vs. +0.251, p=0.003). There was a considerable reduction in maximum corneal curvature (Kmax) in the treatment group (-1.764D) compared to the control group (-0.073D), but this did not achieve statistical significance (p=0.075). Safety parameters such as intraocular pressure and endothelial cell count were also measured, and found to have no difference between the two groups.
The use of collagen cross-linking for the prevention of progression of keratoconus is a promising medical treatment for this disease. Our preliminary data demonstrate a significant reduction of spherical and total aberration, and approaches significance in reduction of maximum corneal curvature. Further interpretation of patient data through the 2 year follow-up period will shed more light on the efficacy of this treatment.
Clinical Trial: :
This PDF is available to Subscribers Only