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Liu X, Yan L, Wei J, Wu C, Zhang J, Song J, Gao Z, Ben Hilal H, Li X, Chen W. Permeation characteristics and cross-linking efficacy of iontophoresis-assisted riboflavin delivery for accelerated riboflavin-ultraviolet A scleral collagen cross-linking in porcine eyes. Exp Eye Res 2024; 248:110095. [PMID: 39284506 DOI: 10.1016/j.exer.2024.110095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 09/02/2024] [Accepted: 09/12/2024] [Indexed: 09/22/2024]
Abstract
The purpose of this study is to investigate whether the iontophoresis-assisted riboflavin delivery to posterior sclera with less delivery time, can achieve the same riboflavin permeation efficiency as the passive soaking way, and its effect on the mechanical properties of posterior sclera for accelerated scleral collagen cross-linking (A-SXL). In this study, 0.1% riboflavin solution was applied into the posterior sclera of porcine eyes either by the iontophoresis-assisted or passive soaking method, with delivery time of 5, 7.5, 10, 12.5, 15, 17.5, and 20 min, respectively. The fluorescence intensity and the distribution of riboflavin concentration in the 10 μm frozen sections of the sclera were evaluated by fluorescence inverted microscope. The posterior sclera with riboflavin treatment through either the iontophoresis-assisted or the passive soaking method for different durations ranging from 5 to 20 min was treated with ultraviolet A (UVA) irradiation at an intensity of 10 mW/cm2 for 9 min. The elastic modulus was determined at the physiological strain level using the uniaxial tensile test after ASXL. The results showed that the fluorescence intensity of riboflavin increased by prolonging the delivery time in both the iontophoresis and passive soaking groups, and the permeation depth of riboflavin remained constant over 15 min. The fluorescence intensity in the iontophoresis group was significantly higher than in the passive soaking group at 12.5 min and 15 min, respectively. The elastic modulus at 12.5 min in the iontophoresis group was significantly higher than in the passive soaking group at the same delivery time and showed no significant difference compared to the passive soaking group at 20 min. In conclusion, it indicated that iontophoresis-assisted delivery could not only shorten the surgery time but also achieve similar mechanical performance to the passive soaking method in ASXL.
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Affiliation(s)
- Xiaona Liu
- College of Biomedical Engineering, Taiyuan University of Technology, Jinzhong, 030600, China
| | - Lingling Yan
- College of Biomedical Engineering, Taiyuan University of Technology, Jinzhong, 030600, China
| | - Junchao Wei
- College of Biomedical Engineering, Taiyuan University of Technology, Jinzhong, 030600, China
| | - Ce Wu
- College of Biomedical Engineering, Taiyuan University of Technology, Jinzhong, 030600, China
| | - Jie Zhang
- College of Biomedical Engineering, Taiyuan University of Technology, Jinzhong, 030600, China
| | - Jie Song
- College of Biomedical Engineering, Taiyuan University of Technology, Jinzhong, 030600, China
| | - Zhipeng Gao
- College of Biomedical Engineering, Taiyuan University of Technology, Jinzhong, 030600, China
| | - Halima Ben Hilal
- College of Biomedical Engineering, Taiyuan University of Technology, Jinzhong, 030600, China
| | - Xiaona Li
- College of Biomedical Engineering, Taiyuan University of Technology, Jinzhong, 030600, China.
| | - Weiyi Chen
- College of Biomedical Engineering, Taiyuan University of Technology, Jinzhong, 030600, China.
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Lombardo M, Serrao S, Bernava GM, Mencucci R, Fruschelli M, Lombardo G. 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; 262:2569-2577. [PMID: 38502352 DOI: 10.1007/s00417-024-06451-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 02/27/2024] [Accepted: 03/08/2024] [Indexed: 03/21/2024] Open
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.
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Affiliation(s)
- Marco Lombardo
- Studio Italiano di Oftalmologia, Via Livenza 3, 00198, Rome, Italy.
- Vision Engineering Italy Srl, Via Livenza 3, 00198, Rome, Italy.
| | - Sebastiano Serrao
- Studio Italiano di Oftalmologia, Via Livenza 3, 00198, Rome, Italy
- Vision Engineering Italy Srl, Via Livenza 3, 00198, Rome, Italy
| | - Giuseppe Massimo Bernava
- CNR-IPCF, Istituto per i Processi Chimico-Fisici, Viale F. Stagno D'Alcontres 37, 98158, Messina, Italy
| | - Rita Mencucci
- SOD Oculistica, AOU Careggi, Università di Firenze, Largo Brambilla 3, 50134, Florence, Italy
| | - Mario Fruschelli
- Sezione Oftalmologia, Policlinico Santa Maria alle Scotte, Università di Siena, Dip. Scienze mediche-chirurgiche e neuroscienze, Viale Bracci, 53100, Siena, Italy
| | - Giuseppe Lombardo
- Studio Italiano di Oftalmologia, Via Livenza 3, 00198, Rome, Italy.
- CNR-IPCF, Istituto per i Processi Chimico-Fisici, Viale F. Stagno D'Alcontres 37, 98158, Messina, Italy.
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Hayes S, Jaycock P, Rees N, Figueiredo FC, O'Brart DPS, Meek KM. National survey of corneal cross-linking (CXL) practice patterns in the United Kingdom during 2019. Eye (Lond) 2023; 37:2511-2517. [PMID: 36539601 PMCID: PMC9767393 DOI: 10.1038/s41433-022-02365-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 12/06/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE To provide an insight into trends in corneal cross-linking (CXL) practice in the UK, including criteria for progression of corneal ectasia, identification of patients for CXL, the CXL procedure itself and post-operative management. METHODS All ophthalmologist members of the UK Cross-linking (UK-CXL) Consortium were invited to complete an online survey about CXL practice for the year 2019. The data collected was anonymised by site and analysed with descriptive statistics. RESULTS Responses were received from 16 individual CXL centres (16/38; 42% response rate) and the data represented ~2,000 CXL procedures performed in the UK in 2019. The commonest indication for CXL was progressive keratoconus. Between centres, there were variations in diagnostic evaluation, patient selection for CXL, the CXL procedure and the pre- and post-operative monitoring of patients. CONCLUSION Consistent with the wide number of CXL treatment techniques described in the published literature world-wide, variations in the monitoring of corneal ectasia, indications for CXL, CXL practice and post-CXL follow-up were found to exist between UK-based CXL centres.
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Affiliation(s)
- Sally Hayes
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK.
| | - Philip Jaycock
- Nuffield Health Bristol Hospital, 3 Clifton Hill, Clifton, Bristol, BS8 1BN, UK
| | - Nicholas Rees
- Bristol Medical School, University of Bristol, 5 Tyndall Avenue, Bristol, BS8 1UD, UK
| | - Francisco C Figueiredo
- Department of Ophthalmology, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Foundation Trust, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP, UK
- Bioscience Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - David P S O'Brart
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
- Keratoconus Research Institute, Department of Ophthalmology, St Thomas Hospital, London, SE1 7EH, UK
| | - Keith M Meek
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
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Borgardts K, Menzel-Severing J, Fischinger I, Geerling G, Seiler TG. Innovations in Corneal Crosslinking. Curr Eye Res 2023; 48:144-151. [PMID: 36458595 DOI: 10.1080/02713683.2022.2146725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
PURPOSE Corneal Crosslinking (CXL) strengthens the keratoconus cornea and prevents further disease progression. Modified crosslinking protocols and different riboflavin solutions have been proposed to optimize the procedure and improve treatment success. METHODS PubMed research of relevant publications and report of own experiences with different CXL protocols. RESULTS Accelerated CXL shows comparable efficiency with shorter surgery time and similar complication rates. Customized CXL provides improved results with faster epithelial healing. CXL in a hyperoxic environment seems to be a safe and effective transepithelial alternative with presumably less complications and fewer side effects. Thin corneas (<400 µm) can be treated safely by corneal swelling using hypoosmolar riboflavin solutions and reducing the applied UV-energy. The combination of CXL with photorefractive keratectomy (PRK) can be considered in patients with contact lens intolerance improving visual acuity, however, with increased risk of visual loss compared to CXL alone. Two-Photon (2Ph) CXL is a promising new technology enabling three-dimensional CXL. DISCUSSION Recently developed CXL protocols offer advantages over the standard "Dresden-protocol" and should be considered in patients with progressive keratectasia.
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Affiliation(s)
- Klara Borgardts
- Department of Ophthalmology, University Hospital Düsseldorf, Düsseldorf, Germany
| | | | - Isaak Fischinger
- Institut für Refraktive and Ophthalmo-Chirurgie (IROC), Zürich, Switzerland.,Department of Ophthalmology, Kepler University Hospital, Linz, Austria.,Medical Faculty, Johannes Kepler University Linz, Linz, Austria
| | - Gerd Geerling
- Department of Ophthalmology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Theo G Seiler
- Department of Ophthalmology, University Hospital Düsseldorf, Düsseldorf, Germany.,Institut für Refraktive and Ophthalmo-Chirurgie (IROC), Zürich, Switzerland.,Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland
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Li Q, Zhao H, Wang H, Zhao G. Properties of the acellular porcine cornea crosslinked with UVA/riboflavin as scaffolds for Boston Keratoprosthesis. BIOMATERIALS ADVANCES 2022; 137:212822. [PMID: 35929237 DOI: 10.1016/j.bioadv.2022.212822] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 03/29/2022] [Accepted: 04/20/2022] [Indexed: 06/15/2023]
Abstract
The Boston Keratoprosthesis type I (B-KPro) is widely used in the world, but the lack of donor corneas limits its application. This study aims to prepare the acellular porcine cornea (APC) crosslinked with ultraviolet A (UVA)/riboflavin instead of donor corneas as the scaffold for B-KPro. Decellularization of freeze-thaw combined with biological enzymes resulted in approximately 5 ng/mg DNA residue, the a-Gal removal rate of 99%, and glycosaminoglycans retention at a high level of 46.66 ± 2.59 mg/mg. UVA/ riboflavin cross-linking was adopted to induce the formation of new chemical bonds between adjacent collagen chains in the corneal stroma to improve the mechanical properties and resistance to enzymatic hydrolysis. Through comprehensive analysis of the biomechanics, enzyme degradation, immunogenicity and histological structure of the APC crosslinked at different times, CL3 (irradiation conditions, 365 nm, 3 mW/cm, 80 min, both sides) was selected and transplanted into the rabbit cornea model through interlamellar keratoplasty and penetrating keratoplasty as the scaffold of the B-KPro. Compared with the native porcine cornea (NPC) and APC, the experiment of interlamellar pocket indicated that the structure of CL3 was homogeneous without degradation and vascularization in vivo at 12 weeks after surgery. Simultaneously, the results of transplantation of B-KPro showed complete epithelialization of CL3 within 1 week, and neovascularization of the cornea indicated rejection but could be controlled with immunosuppressants. At 3 months postoperatively, the lens of B-KPro remained transparent, and the structure of CL3 was compact and uniform, accompanied by the migration and proliferation of a large number of stromal cells without degradation, suggesting the CL3 could be a promising corneal substitute.
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Affiliation(s)
- Qing Li
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan, Shandong, China
| | - Haibin Zhao
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan, Shandong, China; Shenzhen Research Institute of Shandong University, Shenzhen, Guangdong, China.
| | - Hongmei Wang
- Qingdao Chunghao Tissue Engineering Co., Ltd., Qingdao, Shandong, China
| | - Guoqun Zhao
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan, Shandong, China
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Borgardts K, Menzel-Severing J, Geerling G, Seiler TG. [Treatment indications for corneal crosslinking and clinical results of new corneal crosslinking techniques]. Ophthalmologe 2022; 119:350-357. [PMID: 35147774 DOI: 10.1007/s00347-022-01579-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2022] [Indexed: 10/19/2022]
Abstract
BACKGROUND Corneal crosslinking (CXL) is used in keratoconus to strengthen and stabilize the cornea and to prevent further progression with subsequent visual loss and the possible need for keratoplasty. Correct treatment indications is crucial in this context. Since the introduction of the initial Dresden protocol, other modified CXL protocols have been proposed to optimize treatment success. OBJECTIVE The relevant parameters for treatment indications are explained and the clinical results of new CXL protocols are presented. METHODS The currently valid criteria with respect to the indications for CXL in keratoconus, PubMed search for relevant publications and own experiences with different CXL protocols are presented. RESULTS The reproducibility of topographic parameters depends on the stage of the keratoconus. Accelerated CXL as well as transepithelial CXL with a hyperoxic environment show comparable efficiency with shorter surgery time and possibly lower complication rates. Customized CXL with an individualized UV irradiation profile provides improved results with faster epithelial healing. Lower UV energy doses enable CXL to be conducted in eyes with minimal stromal pachymetry of less than 400 µm before irradiation. The combination of CXL with photorefractive keratectomy (PRK) provides visual acuity improvements but also increases the risk of visual loss. CONCLUSION Current indication rules for CXL neglect the reduced reproducability of topographic and tomographic measurements in keratoconus. The latest CXL protocols presented here provide a safe alternative with similar and/or better efficacy compared to standard CXL. The combination of CXL with PRK offers an option for visual rehabilitation in patients with contact lens intolerance.
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Affiliation(s)
- Klara Borgardts
- Klinik für Augenheilkunde, Universitätsklinikum Düsseldorf, Moorenstr. 5, 40225, Düsseldorf, Deutschland
| | - Johannes Menzel-Severing
- Klinik für Augenheilkunde, Universitätsklinikum Düsseldorf, Moorenstr. 5, 40225, Düsseldorf, Deutschland
| | - Gerd Geerling
- Klinik für Augenheilkunde, Universitätsklinikum Düsseldorf, Moorenstr. 5, 40225, Düsseldorf, Deutschland
| | - Theo G Seiler
- Klinik für Augenheilkunde, Universitätsklinikum Düsseldorf, Moorenstr. 5, 40225, Düsseldorf, Deutschland. .,Institut für Refraktive und Ophthalmo-Chirurgie (IROC), Stockerstr. 37, 8002, Zürich, Schweiz. .,Klinik für Augenheilkunde, Universitätsspital Bern, Inselspital Bern, 3010, Bern, Schweiz.
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