Decreased Riboflavin Impregnation Time Does Not Increase the Risk for Endothelial Phototoxicity During Corneal Cross-Linking

Arie L. Marcovich, Jurriaan Brekelmans, Alexander Brandis, Ilan Samish, Iddo Pinkas, Dina Preise, Keren Sasson, Ilan Feine, Alexandra Goz, Mor M. Dickman, Rudy M. M. A. Nuijts, Avigdor Scherz*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

2 Citations (Web of Science)

Abstract

Purpose: To evaluate the riboflavin (RF) concentration and distribution in the corneal stroma and the risk for endothelial photodamage during corneal crosslinking (CXL) following 10- and 30-minute impregnation.

Methods: De-epithelialized rabbit corneas were subjected to impregnation for 10 and 30 minutes with different RF formulations. Human corneal endothelial cells (HCECs) were subjected to different RF concentrations and ultraviolet A (UVA) dosages. Assays included fluorescence imaging, absorption spectroscopy of corneal buttons and anterior chamber humor, and cell viability staining.

Results: After 10 and 30 minutes of impregnation, respectively, anterior chamber fluid showed an RF concentration of (1.6 +/- 0.21).10(-4)% and (5.4 +/- 0.21).10(-4)%, and trans-corneal absorption reported an average corneal RF concentration of 0.0266% and 0.0345%. This results in a decrease in endothelial RF concentration from 0.019% to 0.0056%, whereas endothelial UVA irradiance increases by 1.3-fold when changing from 30 to 10 minutes of impregnation. HCEC viability in cultures exposed to UVA illumination and RF concentrations as concluded for the endothelium after 10- and 30-minute impregnation was nonstatistically different at 51.0%+/- 3.9 and 41.3 +/- 5.0%, respectively.

Conclusions: The risk for endothelial damage in CXL by RF/UVA treatment does not increase by shortened impregnation because the 30% increase in light intensity is accompanied by a 3.4-fold decrease of the RF concentration in the posterior stroma. This is substantiated by similar endothelial cell toxicity seen in vitro, which in fact appears to favor 10-minute impregnation.

Translational Relevance: This study offers compelling arguments for (safely) shortening RF impregnation duration, reducing patients' burden and costly operation room time.

Original languageEnglish
Article number4
Number of pages13
JournalTranslational Vision Science & Technology
Volume9
Issue number6
DOIs
Publication statusPublished - May 2020

Keywords

  • riboflavin
  • endothelial safety
  • corneal collagen cross-linking
  • keratoconus
  • 2-PHOTON FLUORESCENCE MICROSCOPY
  • ULTRAVIOLET-A LIGHT
  • PROGRESSIVE KERATOCONUS
  • CONFOCAL MICROSCOPY
  • RIBOFLAVIN/ULTRAVIOLET
  • CYTOTOXICITY
  • DEXTRAN
  • SAFETY
  • STROMA
  • DAMAGE

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