Analysis of riboflavin/ultraviolet a corneal cross-linking by molecular spectroscopy

Research output: Contribution to journalResearch articleContributedpeer-review


Corneal cross-linking (CXL) with riboflavin and ultraviolet A light is a therapeutic procedure to restore the mechanical stability of corneal tissue. The treatment method is applied to pathological tissue, such as keratoconus and induces the formation of new cross-links. At present, the molecular mechanisms of induced cross-linking are still not known exactly. In this study, we investigated molecular alterations within porcine cornea tissue after treatment with riboflavin and ultraviolet A light by surface enhanced Raman spectroscopy (SERS). For that purpose, after CXL treatment a thin silver layer was vapor-deposited onto cornea flaps. To explore molecular alterations induced by the photochemical process hierarchical cluster analysis (HCA) was used. The detailed analysis of SERS spectra reveals that there is no general change in collagen secondary structure while modifications on amino acid side chains are the most dominant outcome. The formation of secondary and aromatic amine groups as well as methylene and carbonyl groups were observed. Even though successful cross-linking could not be registered in all treated samples, Raman signals of newly formed chemical groups are already present in riboflavin only treated corneas.


Original languageEnglish
Article numbere13206
Number of pages11
Issue number2
Publication statusPublished - Feb 2023

External IDs

WOS 000969407300001
ORCID /0000-0002-0633-0321/work/141544806
ORCID /0000-0002-8160-3000/work/142248351
ORCID /0000-0003-0554-2178/work/142249892
ORCID /0000-0003-0829-7577/work/150330585
ORCID /0000-0002-7625-343X/work/150881394
PubMed 36747519
PubMedCentral PMC9898066


ASJC Scopus subject areas


  • Collagen, Corneal cross-linking, Keratoconus, Riboflavin, Surface enhanced Raman spectroscopy

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