SpringerLink
Log in

Real-time monitoring of riboflavin concentration using different clinically available ophthalmic formulations for epi-off and epi-on corneal cross-linking

  • Cornea
  • Published:
Graefe's Archive for Clinical and Experimental Ophthalmology Aims and scope Submit manuscript

Abstract

Purpose

To assess the feasibility of theranostics to determine the riboflavin concentration in the cornea using clinically available ophthalmic formulations during epithelium-off (epi-off) and transepithelial (epi-on) corneal cross-linking procedures.

Methods

Thirty-two eye bank human donor corneas were equally randomized in eight groups; groups 1 to 3 and groups 4 to 8 underwent epi-off and epi-on delivery of riboflavin respectively. Riboflavin ophthalmic solutions were applied onto the cornea according to the manufacturers’ instructions. The amount of riboflavin into the cornea was estimated, at preset time intervals during imbibition time, using theranostic UV-A device (C4V CHROMO4VIS, Regensight srl, Italy) and expressed as riboflavin score (d.u.). Measurements of corneal riboflavin concentration (expressed as µg/cm3) were also performed by spectroscopy absorbance technique (AvaLight-DH-S-BAL, Avantes) for external validation of theranostic measurements.

Results

At the end of imbibition time in epi-off delivery protocols, the average riboflavin score ranged from 0.77 ± 0.38 (the average corneal riboflavin concentration was 213 ± 190 µg/cm3) to 1.79 ± 0.07 (554 ± 103 µg/cm3). In epi-on delivery protocols, the average riboflavin score ranged from 0.17 ± 0.01 to 0.67 ± 0.19 (corneal riboflavin concentration ranged from 6 ± 5 µg/cm3 to 122 ± 39 µg/cm3) at the end of imbibition time. A statistically significant linear correlation (P ≤ 0.05) was found between the theranostic and spectrophotometry measurements in all groups.

Conclusions

Real-time theranostic imaging provided an accurate strategy for assessing permeation of riboflavin into the human cornea during the imbibition phase of corneal cross-linking, regardless of delivery protocol. A large variability in corneal riboflavin concentration exists between clinically available ophthalmic formulations both in epi-off and epi-on delivery protocols.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price includes VAT (Germany)

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

References

  1. Meiri Z, Keren S, Rosenblatt A, Sarig T, Shenhav L, Varssano D (2016) Efficacy of corneal collagen cross-linking for the treatment of keratoconus: a systematic review and meta-analysis. Cornea 35(3):417–428

    Article  PubMed  Google Scholar 

  2. Serrao S, Lombardo G, Lombardo M (2022) Adverse events after riboflavin/UV-A corneal cross-linking: a literature review. Int Ophthalmol 42(1):337–348

    Article  PubMed  Google Scholar 

  3. Hersh PS, Stulting RD, Muller D, Durrie DS, Rajpal RK, United States Crosslinking Study Group (2017) United States multicenter clinical trial of corneal collagen crosslinking for keratoconus treatment. Ophthalmology 124(9):1259–1270

    Article  Google Scholar 

  4. Chunyu T, **ujun P, Zhengjun F, **a Z, Feihu Z (2014) Corneal collagen cross-linking in keratoconus: a systematic review and meta-analysis. Sci Rep 4:5652

    Article  PubMed  PubMed Central  Google Scholar 

  5. Koller T, Mrochen M, Seiler T (2009) Complication and failure rates after corneal crosslinking. J Cataract Refract Surg 35:1358–1362

    Article  PubMed  Google Scholar 

  6. Lombardo M, Pucci G, Barberi R, Lombardo G (2015) Interaction of ultraviolet light with the cornea: clinical implications for corneal crosslinking. J Cataract Refract Surg 41(2):446–459

    Article  PubMed  Google Scholar 

  7. Tao X, Yu H, Zhang Y et al (2013) Role of corneal epithelium in riboflavin/ultraviolet-A mediated corneal cross-linking treatment in rabbit eyes. Biomed Res Int 2013:624563

    Article  PubMed  PubMed Central  Google Scholar 

  8. Koppen C, Gobin L, Tassignon M-J (2010) The absorption characteristics of the human cornea in ultraviolet-A crosslinking. Eye Contact Lens 2:77–80

    Article  Google Scholar 

  9. Lombardo M, Micali N, Villari V et al (2015) Ultraviolet A - visible spectral absorbance of the human cornea after transepithelial soaking with dextran-enriched and dextran-free riboflavin 0.1% ophthalmic solutions. J Cataract Refract Surg 41:2283–2290

  10. Baiocchi S, Mazzotta C, Cerretani D, Caporossi T, Caporossi A (2009) Corneal crosslinking: riboflavin concentration in corneal stroma exposed with and without epithelium. J Cataract Refract Surg 35:893–899

    Article  PubMed  Google Scholar 

  11. Ng SM, Ren M, Lindsley KB, Hawkins BS, Kuo IC (2021) Transepithelial versus epithelium-off corneal crosslinking for progressive keratoconus. Cochrane Database Syst Rev (3):CD013512

  12. Kamaev P, Friedman MD, Sherr E, Muller D (2012) Photochemical kinetics of corneal cross-linking with riboflavin. Invest Ophthalmol Vis Sci 53:2360–2367

    Article  PubMed  Google Scholar 

  13. Sel S, Nass N, Pötzsch S et al (2014) UVA irradiation of riboflavin generates oxygen-dependent hydroxyl radicals. Redox Rep 19:72–79

    Article  CAS  PubMed  Google Scholar 

  14. Schumacher S, Mrochen M, Wernli J, Bueeler M, Seiler T (2012) Optimization model for UV-Riboflavin corneal cross-linking. Invest Ophthalmol Vis Sci 53:762–769

    Article  CAS  PubMed  Google Scholar 

  15. Lin J-T, Cheng D-C (2017) Modeling the efficacy profiles of UV-light activated corneal collagen crosslinking. PLoS ONE 12(4):e0175002

    Article  PubMed  PubMed Central  Google Scholar 

  16. Lombardo G, Villari V, Micali N et al (2018) Non-invasive optical method for real-time assessment of intracorneal riboflavin concentration and efficacy of corneal cross-linking. J Biophotonics 11(7):e201800028

    Article  PubMed  Google Scholar 

  17. Lombardo G, Bernava GM, Serrao S, Lombardo M (2022) Theranostic-guided corneal cross-linking: pre-clinical evidence on a new treatment paradigm for keratoconus. J Biophotonics 15(12):e202200218

    Article  CAS  PubMed  Google Scholar 

  18. Lombardo G, Bernava GM, Serrao S, Roszkwoska AM, Lombardo M (2023) Predicting corneal cross-linking treatment efficacy with real-time assessment of corneal riboflavin concentration. J Cataract Refract Surg 49(6):635–641

    Article  PubMed  Google Scholar 

  19. Lombardo M, Micali N, Villari V, Serrao S, Lombardo G (2016) All-optical method to assess stromal concentration of riboflavin in conventional and accelerated UV-A irradiation of the human cornea. Invest Opthalmol Vis Sci 57(2):476–483

    Article  CAS  Google Scholar 

  20. Wollensak G, Iomdina E (2009) Biomechanical and histological changes after corneal crosslinking with and without epithelial debridement. J Cataract Refract Surg 35:540–546

    Article  PubMed  Google Scholar 

  21. Rosenblat E, Hersh PS (2016) Intraoperative corneal thickness change and clinical outcomes after corneal collagen crosslinking: standard crosslinking versus hypotonic riboflavin. J Cataract Refract Surg 42(4):596–605

    Article  PubMed  Google Scholar 

  22. Ehmke T, Seiler TG, Fischinger I, Ripken T, Heisterkamp A, Frueh BE (2016) Comparison of corneal riboflavin gradients using dextran and HPMC solutions. J Refract Surg 32(12):798–802

    Article  PubMed  Google Scholar 

  23. Rubinfeld RS, Stulting RD, Gum GG, Talamo JH (2018) Quantitative analysis of corneal stromal riboflavin concentration without epithelial removal. J Cataract Refract Surg 44:237–242

    Article  PubMed  Google Scholar 

  24. Hayes S, Morgan SR, O’Brart DP, O’Brart N, Meek KM (2016) A study of stromal riboflavin absorption in ex vivo porcine corneas using new and existing delivery protocols for corneal cross-linking. Acta Ophthalmol 94:e109–e117

    Article  CAS  PubMed  Google Scholar 

  25. Al Fayez MF, Alfayez S, Alfayez Y (2015) Transepithelial versus epithelium-off corneal collagen cross-linking for progressive keratoconus: a prospective randomized controlled trial. Cornea 34(Suppl 10):S53-56

    Article  PubMed  Google Scholar 

  26. D’Oria F, Palazón A, Alio JL (2021) Corneal collagen cross-linking epithelium-on vs. epithelium-off: a systematic review and meta-analysis. Eye Vis (Lond) 8(1):34

  27. Zhang X, Zhao J, Li M, Tian M, Shen Y, Zhou X (2018) Conventional and transepithelial corneal cross-linking for patients with keratoconus. PLoS ONE 13(4):e0195105

    Article  PubMed  PubMed Central  Google Scholar 

  28. Kaur IP, Smitha R (2002) Penetration enhancers and ocular bioadhesives: two new avenues for ophthalmic drug delivery. Drug Dev Ind Pharm 28:353–369

    Article  CAS  PubMed  Google Scholar 

  29. Raiskup F, Pinelli R, Spoerl E (2012) Riboflavin osmolar modification for transepithelial corneal cross-linking. Curr. Eye Res 37(3):234–238

    Article  CAS  PubMed  Google Scholar 

  30. O’Brart NAL, O’Brart DPS, Aldahlawi NH, Hayes S, Meek KM (2018) An investigation of the effects of riboflavin concentration on the efficacy of corneal cross-linking using an enzymatic resistance model in porcine corneas. Invest Ophthalmol Vis Sci 59:1058–1065

    Article  PubMed  Google Scholar 

  31. Franke MAD, Landes T, Seiler TG et al (2021) Corneal riboflavin gradients and UV-absorption characteristics after topical application of riboflavin in concentrations ranging from 0.1 % to 0.5%. Exp Eye Res 213:108842

  32. Iseli HP, Popp M, Seiler T, Spoerl E, Mrochen M (2011) Laboratory measurement of the absorption coefficient of riboflavin for ultraviolet light (365 nm). J Refract Surg 27:1952–2001

    Article  Google Scholar 

  33. Lombardo G, Serrao S, Lombardo M (2020) Comparison between standard and transepithelial corneal crosslinking using a theranostic UV-A device. Graefes Arch Clin Exp Ophthalmol 258(4):829–834

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

We are thankful to Davide Camposampiero, Andrea Grassetto, and Diego Ponzin (Veneto Eye Bank Foundation, Venezia Zelarino, Italy) for their work in providing donor tissues for research purpose.

Funding

This study was in part funded by Lazio Innova in the framework of FESR 2021–2027 programme with grant n. A0613-2023–077528 and by PO FESR 2014–2020. Action 1.1.5, project NUSTEO, CUP: G68I18000700007—application code 08CT2120090065.

Author information

Authors and Affiliations

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

    Marco Lombardo, Sebastiano Serrao & Giuseppe Lombardo

  2. Vision Engineering Italy Srl, Via Livenza 3, 00198, Rome, Italy

    Marco Lombardo & Sebastiano Serrao

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

    Giuseppe Massimo Bernava & Giuseppe Lombardo

  4. SOD Oculistica, AOU Careggi, Università di Firenze, Largo Brambilla 3, 50134, Florence, Italy

    Rita Mencucci

  5. Sezione Oftalmologia, Policlinico Santa Maria alle Scotte, Università di Siena, Dip. Scienze mediche-chirurgiche e neuroscienze, Viale Bracci, 53100, Siena, Italy

    Mario Fruschelli

Authors
  1. Marco Lombardo
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Sebastiano Serrao
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Giuseppe Massimo Bernava
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Rita Mencucci
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Mario Fruschelli
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Giuseppe Lombardo
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding authors

Correspondence to Marco Lombardo or Giuseppe Lombardo.

Ethics declarations

Ethical approval

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

Conflict of interest

Marco Lombardo and Giuseppe Lombardo are co-inventors on issued family patent (IT102019000011985, CN114126650, and US20230131004) related to this work. Marco Lombardo, Giuseppe Lombardo, and Sebastiano Serrao are equity owners in Regensight srl. Mario Fruschelli, Rita Mencucci, and Giuseppe Massimo Bernava have no conflict of interest.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (DOCX 17 KB)

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Lombardo, M., Serrao, S., Bernava, G.M. et al. Real-time monitoring of riboflavin concentration using different clinically available ophthalmic formulations for epi-off and epi-on corneal cross-linking. Graefes Arch Clin Exp Ophthalmol (2024). https://doi.org/10.1007/s00417-024-06451-8

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s00417-024-06451-8

Keywords

Search

Navigation