Seiler, Theo G.; Batista, Ana; Frueh, Beatrice E.; Koenig, Karsten (2019). Riboflavin Concentrations at the Endothelium During Corneal Cross-Linking in Humans. Investigative ophthalmology & visual science, 60(6), pp. 2140-2145. Association for Research in Vision and Ophthalmology 10.1167/iovs.19-26686
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Riboflavin Concentrations at the Endothelium During CXL in Humans - IOVS.pdf - Published Version Available under License Creative Commons: Attribution-Noncommercial-No Derivative Works (CC-BY-NC-ND). Download (1MB) | Preview |
Purpose
To determine the riboflavin concentration in the posterior corneal stroma, Descemet's membrane, and endothelium prior to UV irradiation in corneal cross-linking (CXL) in humans.
Methods
Five human deepithelialized cadaver corneas were mounted into artificial anterior chambers. After the establishment of stable physiological hydration, two-photon imaging with a certified multiphoton tomograph was used to determine fluorescence intensity and second harmonic generation signals from collagen throughout each cornea by optical sectioning, with a step size of 2.5 μm. Afterward, 0.1% riboflavin solution was applied to the anterior corneal surface, similar to the standard CXL protocol. To determine the absolute riboflavin concentration immediately before UV irradiation, corneas were measured by two-photon imaging just at the end of the riboflavin imbibition and after riboflavin saturation.
Results
The topical application of 0.1% riboflavin results in a riboflavin concentration that decreases to 0.035% in the posterior stroma. Inside Descemet's membrane and endothelium, the concentration drops further to only approximately 0.015% at the endothelial level. Local riboflavin distribution indicates a predominantly paracellular passive diffusion of riboflavin into the anterior chamber.
Conclusion
The experimentally determined riboflavin concentration of 0.015% at the endothelium shows a substantial discrepancy of a factor of 1.7 to the previously theoretically calculated 0.025%. A lower riboflavin concentration at the endothelium may enable higher radiant exposures and further improve the efficacy of CXL.
Item Type: |
Journal Article (Original Article) |
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Division/Institute: |
04 Faculty of Medicine > Department of Head Organs and Neurology (DKNS) > Clinic of Ophthalmology |
UniBE Contributor: |
Seiler, Günter Theodor Michael, Früh Epstein, Beatrice |
Subjects: |
600 Technology > 610 Medicine & health |
ISSN: |
0146-0404 |
Publisher: |
Association for Research in Vision and Ophthalmology |
Language: |
English |
Submitter: |
Günter Theodor Michael Seiler |
Date Deposited: |
07 Aug 2019 09:40 |
Last Modified: |
05 Dec 2022 15:29 |
Publisher DOI: |
10.1167/iovs.19-26686 |
PubMed ID: |
31099830 |
BORIS DOI: |
10.7892/boris.131708 |
URI: |
https://boris.unibe.ch/id/eprint/131708 |