Studies on molecular changes in corneal tissue in response to treatment with riboflavin and ultraviolet radiation using infrared spectroscopy

Collagen cross-linking with riboflavin and UVA light is a therapeutic procedure invented at the University Hospital Dresden to restore the mechanical stability of corneal tissue. The treatment method applies to pathological tissue changes, such as keratoconus, and induces the photochemical formation of new collagen cross-links. Therefore, progression of keratoconus in early stages can be stopped and a possible corneal transplantation might be prevented. At present, it is still not known exactly what the nature of the cross-links is and how they are formed.

IR Spektren Hornhaut — IR spectra of thin section of porcine cornea

In this project, molecular changes induced by the cross-linking therapy are investigated preferably by using Fourier transform infrared (FT-IR) spectroscopic imaging techniques. To perform basic research, thin sections of porcine corneas were prepared especially for this purpose. Via imaging they enable the registration of thousands of spectra simultaneously. In order to extract the small signals in a reliable way, the imaging data is subjected to multivariate statistics. For further studies, Attenuated total reflection (ATR) spectroscopy is used to investigate the cross-linking process in situ. The results demonstrate that new cross-links are formed predominantly between collagen protein side chains.