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Comparison between standard and transepithelial corneal crosslinking using a theranostic UV-A device

  • Cornea
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Abstract

Purpose

To assess corneal concentration of riboflavin in two different corneal crosslinking protocols performed by a novel image-guided therapeutic (or “theranostic”) UV-A device.

Methods

Ten human eye bank donor tissues were used in this work. The tissues underwent corneal cross-linking according to the conventional treatment protocol (n = 5; 30 min of stromal soaking followed by 30 min of 3 mW/cm2 UV-A irradiance) and the iontophoresis-assisted transepithelial protocol (n = 5; soaking for 5 min at 1 mA/min and 9 min of 10 mW/cm2 UV-A irradiance) using a theranostic UV-A device (Vision Engineering Italy srl, Italy). The device provided real time assessment of riboflavin concentration by hyperspectral image analysis of the cornea. A 0.1% riboflavin hypotonic solution (Ricrolin+, Sooft Italia Spa, Italy) was used in all cases.

Results

Manual application of hypotonic riboflavin for 30 min into the stroma achieved greater corneal riboflavin concentration (425 ± 77 μg/cm3) than transepithelial delivery of riboflavin by corneal iontophoresis (195 ± 35 μg/cm3; P = 0.001). In both UV-A irradiation protocols, corneal riboflavin concentration decreased exponentially with a constant energy rate of 2.3 ± 0.5 J/cm2 and 1.8 ± 0.3 J/cm2 respectively. At the end of treatment, the average corneal concentration of riboflavin decreased by ≥ 85%, with values of 54 ± 29 μg/cm3 and 31 ± 9 μg/cm3 (P = 0.11), respectively.

Conclusion

Manual application of riboflavin onto the stroma achieved almost 50% greater concentration of riboflavin than transepithelial delivery by corneal iontophoresis. The theranostic UV-A device provided a novel approach to estimate corneal concentration of riboflavin non-invasively during treatment.

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Acknowledgments

We are thankful to Giuseppe Lupò (Consiglio Nazionale delle Ricerche, Istituto per i processi Chimico Fisici, Messina, Italy) for his support in assembling the electronic and mechanical part of the device and Chiara Mustarelli (Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica) for assistance in preparing documents for ethics committee approval. We also thank Sooft Italia Spa – Fidia Pharma group for providing the riboflavin solutions used in this work.

Funding

This study was funded by Lazio Innova POR FESR 2014-2020, grant no. A0114-2017-13,715.

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Authors and Affiliations

  1. Vision Engineering Italy srl, Via Livenza 3, 00198, Rome, Italy

    Giuseppe Lombardo & Marco Lombardo

  2. CNR-IPCF, Istituto per i Processi Chimico-Fisici, Viale F. Stagno D’Alcontres 37, 98158, Messina, Italy

    Giuseppe Lombardo

  3. Studio Italiano di Oftalmologia, Via Livenza 3, 00198, Rome, Italy

    Sebastiano Serrao & Marco Lombardo

Authors
  1. Giuseppe Lombardo
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  2. Sebastiano Serrao
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Correspondence to Marco Lombardo.

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Conflict of interest

Marco Lombardo and Giuseppe Lombardo declare that they are co-inventors on an issued patent (IT102016000007349) and a pending patent application (WO2017130043A1) related to this work and that they are shareholders of Vision Engineering Italy srl. Sebastiano Serrao declares that he has no conflict of interest.

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This article does not contain any studies with human participants or animals performed by any of the authors.

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Lombardo, G., Serrao, S. & Lombardo, M. Comparison between standard and transepithelial corneal crosslinking using a theranostic UV-A device. Graefes Arch Clin Exp Ophthalmol 258, 829–834 (2020). https://doi.org/10.1007/s00417-019-04595-6

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  • DOI: https://doi.org/10.1007/s00417-019-04595-6

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