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Leonardi F, Simonazzi B, Martini FM, D’Angelo P, Foresti R, Botti M. Synthetic and Natural Biomaterials in Veterinary Medicine and Ophthalmology: A Review of Clinical Cases and Experimental Studies. Vet Sci 2024; 11:368. [PMID: 39195822 PMCID: PMC11360824 DOI: 10.3390/vetsci11080368] [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: 06/25/2024] [Revised: 08/08/2024] [Accepted: 08/10/2024] [Indexed: 08/29/2024] Open
Abstract
In recent years, there has been a growing interest in 3D printing technology within the field of bioengineering. This technology offers the ability to create devices with intricate macro- and micro-geometries, as well as specific models. It has particularly gained attention for its potential in personalized medicine, allowing for the production of organ or tissue models tailored to individual patient needs. Further, 3D printing has opened up possibilities to manufacture structures that can substitute, complement, or enhance damaged or dysfunctional organic parts. To apply 3D printing in the medical field, researchers have studied various materials known as biomaterials, each with distinct chemical and physical characteristics. These materials fall into two main categories: hard and soft materials. Each biomaterial needs to possess specific characteristics that are compatible with biological systems, ensuring long-term stability and biocompatibility. In this paper, we aim to review some of the materials used in the biomedical field, with a particular focus on those utilized in veterinary medicine and ophthalmology. We will discuss the significant findings from recent scientific research, focusing on the biocompatibility, structure, applicability, and in vitro and in vivo biological characteristics of two hard and four soft materials. Additionally, we will present the current state and prospects of veterinary ophthalmology.
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Affiliation(s)
- Fabio Leonardi
- Department of Veterinary Science, University of Parma, 43126 Parma, Italy; (F.L.); (F.M.M.); (M.B.)
| | - Barbara Simonazzi
- Department of Veterinary Science, University of Parma, 43126 Parma, Italy; (F.L.); (F.M.M.); (M.B.)
| | - Filippo Maria Martini
- Department of Veterinary Science, University of Parma, 43126 Parma, Italy; (F.L.); (F.M.M.); (M.B.)
| | - Pasquale D’Angelo
- CNR-IMEM, Italian National Research Council, Institute of Materials for Electronics and Magnetism, 43126 Parma, Italy; (P.D.); (R.F.)
| | - Ruben Foresti
- CNR-IMEM, Italian National Research Council, Institute of Materials for Electronics and Magnetism, 43126 Parma, Italy; (P.D.); (R.F.)
- Department of Medicine and Surgery, University of Parma, 43123 Parma, Italy
- CERT, Center of Excellence for Toxicological Research, 43123 Parma, Italy
| | - Maddalena Botti
- Department of Veterinary Science, University of Parma, 43126 Parma, Italy; (F.L.); (F.M.M.); (M.B.)
- CNR-IMEM, Italian National Research Council, Institute of Materials for Electronics and Magnetism, 43126 Parma, Italy; (P.D.); (R.F.)
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Gustafsson I, Olafsdotttir T, Neumann O, Johansson P, Bizios D, Ivarsen A, Hjortdal JØ. Early findings in a randomised controlled trial on crosslinking protocols using isoosmolar and hypoosmolar riboflavin for the treatment of progressive keratoconus. Acta Ophthalmol 2024. [PMID: 38970233 DOI: 10.1111/aos.16736] [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: 02/27/2024] [Accepted: 06/22/2024] [Indexed: 07/08/2024]
Abstract
PURPOSE To present baseline characteristics and to present the perioperative corneal thickness during corneal crosslinking (CXL) treatment for progressive keratoconus and to describe how the addition of sterile water (SW) efficaciously can maintain the corneal thickness. The treatment efficacy will be evaluated when the 1-year follow-up is complete. METHODS A randomised clinical study using epithelium-off CXL with continuous UVA irradiation (9 mW/cm2) and two kinds of riboflavin solutions: (i) isoosmolar dextran-based riboflavin (n = 27) and (ii) hypoosmolar dextran-free riboflavin (n = 27). INCLUSION CRITERIA progressive keratoconus with an increase in maximum keratometry value (Kmax) of 1.0 dioptre (12 months) or 0.5 dioptres (6 months). Corneae thinner than 400 μm were also included. OUTCOME PARAMETERS Perioperative corneal thickness and the effect of adding SW. RESULTS Seventy-four per cent of the patients in the isoosmolar group and 15% in the hypoosmolar group required the addition of SW, which effectively maintained a corneal thickness of 400 μm in all cases during CXL. The addition of SW was primarily needed during the irradiation procedure and not the preoperative soaking period. CONCLUSIONS Especially during the CXL irradiation phase, isoosmolar riboflavin causes a significant dehydrating effect leading to corneal thinning during CXL. The customised addition of SW is efficacious in maintaining the corneal thickness during CXL and could increase the safety of the procedure.
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Affiliation(s)
- Ingemar Gustafsson
- Department of Ophthalmology, Skåne University Hospital, Malmö, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Thorbjörg Olafsdotttir
- Department of Ophthalmology, Skåne University Hospital, Malmö, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Olof Neumann
- Department of Ophthalmology, Skåne University Hospital, Malmö, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Per Johansson
- Department of Ophthalmology, Skåne University Hospital, Malmö, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Dimitrios Bizios
- Department of Ophthalmology, Skåne University Hospital, Malmö, Sweden
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Anders Ivarsen
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark
| | - Jesper Ø Hjortdal
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark
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Safalı F, Ocak SY, Argon BD, Karaca G, Elçioğlu MN. Evaluation of the results of contact lens assisted corneal cross-linking treatment in keratoconus patients with thin corneas. Jpn J Ophthalmol 2024; 68:225-232. [PMID: 38557918 DOI: 10.1007/s10384-024-01055-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 02/20/2024] [Indexed: 04/04/2024]
Abstract
PURPOSE We aimed to compare the efficacy and safety of accelerated contact lens-assisted cross-linking (CA-CXL) with Lotrafilcon B and Comfilcon A lenses in keratoconus (KC) patients with thin corneas. STUDY DESIGN Retrospective, single-center study. MATERIALS AND METHODS We retrospectively included 51 eyes of 39 KC patients with corneal thickness <400µm after epithelial scraping (Epi-off), who underwent accelerated CA-CXL treatment with Lotrafilcon B (n=20) and Comfilcon A (n=31). Uncorrected and corrected distance visual acuity (UDVA and CDVA), manifest refraction values, corneal topographic data and endothelial cell density were recorded at preoperative and postoperative 1st, 3rd and 6th month controls. RESULTS CDVA in the Comfilcon A group was higher than CDVA before surgery at 6 months postoperatively (p<0.001). When the two lenses were compared, CDVA was found to be significantly higher in the Lotrafilcon B group in the preoperative, postoperative 1st month and 3rd month values, but there was no significant difference between the postoperative 6th month values (p=0.028, p=0.018, p=0.044, p=0.181, respectively). The maximum keratometry (Kmax) value at the 6th month after surgery in the Comfilcon A group was significantly lower than in the Lotrafilcon B group (p=0,009). There was no significant difference between the endothelial cell density values between the groups (p=0.623, p=0.609, p=0.794, p=0.458, respectively). There was no significant difference between the progression, regression, and stability rates of the two groups (p=0.714). CONCLUSIONS Accelerated CA-CXL with Lotrafilcon B and Comfilcon A silicone hydrogel lenses is a safe and effective method to stop progression in patients with thin corneas.
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Affiliation(s)
- Fidan Safalı
- Prof.Dr.Cemil Tascioglu City Hospital, Istanbul, Turkey.
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Sachdev GS, Thulasidas M, Sachdev MS. Long-term outcomes of tailored stromal expansion with refractive lenticule for crosslinking thin corneas. Indian J Ophthalmol 2024; 72:94-97. [PMID: 38131577 PMCID: PMC10841800 DOI: 10.4103/ijo.ijo_762_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 09/19/2023] [Accepted: 10/07/2023] [Indexed: 12/23/2023] Open
Abstract
PURPOSE To assess the long-term safety and stability of visual outcomes following the modified technique of collagen crosslinking (CXL) using refractive lenticule in eyes with thin corneas (<400 µm) and progressive keratoconus. SETTING A tertiary eye care hospital in India. DESIGN Prospective, interventional case series. METHODS Eyes with progressive keratoconus and thin corneas (<400 µm) underwent CXL with intraoperative stromal augmentation using a refractive lenticule obtained from small-incision lenticule extraction (SMILE). Preoperative and postoperative evaluation (3 months, and then yearly thereafter) included corneal tomography (Oculus Pentacam), uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively), manifest refraction, and endothelial cell count (specular microscopy), and adverse events, if any, were noted. The patients were followed up for a period of 5 years. RESULTS Seven eyes were included in the analysis. Mean corneal flattening of -4.29 D was noted from preoperative maximum keratometry (P = 0.018). An improvement in UDVA and CDVA of 0.38 logarithm of minimum angle of resolution (logMAR) and 0.36 logMAR, respectively, was noted at 5 years postoperative visit. Four eyes demonstrated a gain of two lines in CDVA. Mean spherical equivalent improved from -6.85 D preoperatively to -6.05 D at 5 years postoperatively. Clear demarcation line was noted between 230 to 270 µm on anterior segment optical coherence topography. No significant endothelial cell loss was noted postoperatively. CONCLUSION Long-term outcomes demonstrated safety and disease stability following lenticule-assisted CXL.
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Affiliation(s)
- Gitansha S Sachdev
- Cornea and Refractive Services, The Eye Foundation, Coimbatore, Tamil Nadu, India
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Deshmukh R, Ong ZZ, Rampat R, Alió del Barrio JL, Barua A, Ang M, Mehta JS, Said DG, Dua HS, Ambrósio R, Ting DSJ. Management of keratoconus: an updated review. Front Med (Lausanne) 2023; 10:1212314. [PMID: 37409272 PMCID: PMC10318194 DOI: 10.3389/fmed.2023.1212314] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 05/30/2023] [Indexed: 07/07/2023] Open
Abstract
Keratoconus is the most common corneal ectatic disorder. It is characterized by progressive corneal thinning with resultant irregular astigmatism and myopia. Its prevalence has been estimated at 1:375 to 1:2,000 people globally, with a considerably higher rate in the younger populations. Over the past two decades, there was a paradigm shift in the management of keratoconus. The treatment has expanded significantly from conservative management (e.g., spectacles and contact lenses wear) and penetrating keratoplasty to many other therapeutic and refractive modalities, including corneal cross-linking (with various protocols/techniques), combined CXL-keratorefractive surgeries, intracorneal ring segments, anterior lamellar keratoplasty, and more recently, Bowman's layer transplantation, stromal keratophakia, and stromal regeneration. Several recent large genome-wide association studies (GWAS) have identified important genetic mutations relevant to keratoconus, facilitating the development of potential gene therapy targeting keratoconus and halting the disease progression. In addition, attempts have been made to leverage the power of artificial intelligence-assisted algorithms in enabling earlier detection and progression prediction in keratoconus. In this review, we provide a comprehensive overview of the current and emerging treatment of keratoconus and propose a treatment algorithm for systematically guiding the management of this common clinical entity.
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Affiliation(s)
- Rashmi Deshmukh
- Department of Cornea and Refractive Surgery, LV Prasad Eye Institute, Hyderabad, India
| | - Zun Zheng Ong
- Department of Ophthalmology, Queen’s Medical Centre, Nottingham, United Kingdom
| | - Radhika Rampat
- Department of Ophthalmology, Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Jorge L. Alió del Barrio
- Cornea, Cataract and Refractive Surgery Unit, Vissum (Miranza Group), Alicante, Spain
- Division of Ophthalmology, School of Medicine, Universidad Miguel Hernández, Alicante, Spain
| | - Ankur Barua
- Birmingham and Midland Eye Centre, Birmingham, United Kingdom
| | - Marcus Ang
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore
| | - Jodhbir S. Mehta
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore
| | - Dalia G. Said
- Department of Ophthalmology, Queen’s Medical Centre, Nottingham, United Kingdom
- Academic Ophthalmology, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Harminder S. Dua
- Department of Ophthalmology, Queen’s Medical Centre, Nottingham, United Kingdom
- Academic Ophthalmology, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Renato Ambrósio
- Department of Cornea and Refractive Surgery, Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil
- Department of Ophthalmology, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Darren Shu Jeng Ting
- Birmingham and Midland Eye Centre, Birmingham, United Kingdom
- Academic Ophthalmology, School of Medicine, University of Nottingham, Nottingham, United Kingdom
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
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Uysal BS, Ozmen MC, Yuksel M, Aydın B, Bilgihan K. Comparison of safety and efficacy of silicone hydrogel contact Lens-assisted CXL and accelerated CXL in keratoconus patients with thin corneas. Eur J Ophthalmol 2023; 33:44-51. [PMID: 36062606 DOI: 10.1177/11206721221125029] [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: 01/11/2023]
Abstract
PURPOSE To evaluate the efficacy and safety of silicone hydrogel contact lens-assisted corneal cross-linking (CL-CXL) and compare 12-month visual and topographic outcomes with accelerated CXL using hypo-osmolar riboflavin (A-CXL) in keratoconus patients with thin corneas (below 400 μm with epithelium). METHODS This retrospective study included 27 eyes of 27 keratoconus patients who underwent CL-CXL (n = 14) or A-CXL (n = 13). Uncorrected and corrected distance visual acuity (UDVA and CDVA) and data obtained from corneal topography were analyzed at baseline and again at 6- and 12-month follow-ups. Corneal demarcation line depth (DLD) was measured at one month, and changes in the corneal endothelial cell density (ECD) at 12 months were also assessed. RESULTS Mean UDVA improved significantly in both groups at 12 months (all p < 0.05). Maximum keratometry (K-max) decreased by 1.04 ± 1.90 D in the CL-CXL group and by 0.87 ± 1.89 D in the A-CXL group at 12 months, which was not statistically significant (all p>0.05). Total corneal higher-order aberrations (HOAs) analysis showed a significant improvement in only the CL-CXL group at 12 months (p = 0.041). Average DLD was 227.18 ± 65.60 μm in the CL-CXL group and 245.30 ± 66.84 μm in the A-CXL group (p = 0.275). No significant change in ECD was found in either group (all p>0.05). Mean changes in UDVA, CDVA, K-max, K-mean, HOAs, and ECD were not statistically significant between the groups (all p>0.05). CONCLUSIONS Silicone hydrogel CL-assisted CXL seems as effective as A-CXL in halting keratoconus progression in thin corneas with no side effects during the one-year follow-up period.
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Affiliation(s)
- Betul Seher Uysal
- Department of Ophthalmology, 37511Gazi University Faculty of Medicine, Ankara, Turkey
| | - Mehmet Cuneyt Ozmen
- Department of Ophthalmology, 37511Gazi University Faculty of Medicine, Ankara, Turkey
| | - Murat Yuksel
- Department of Ophthalmology, 37511Gazi University Faculty of Medicine, Ankara, Turkey
| | - Bahri Aydın
- Department of Ophthalmology, 37511Gazi University Faculty of Medicine, Ankara, Turkey
| | - Kamil Bilgihan
- Department of Ophthalmology, 37511Gazi University Faculty of Medicine, Ankara, Turkey
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A Critical Assessment of Friedenwald’s Technique for Estimating the Coefficient of Rigidity of the Cornea. J Ophthalmol 2022; 2022:6775064. [PMID: 36237558 PMCID: PMC9553366 DOI: 10.1155/2022/6775064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 09/16/2022] [Indexed: 11/18/2022] Open
Abstract
Purpose To determine if Friedenwald's technique for estimating the coefficient of corneal rigidity (Ko, units mmHg/μL), could differentiate between the cornea in keratoconus, normal eyes, and after crosslinking (CXL). Methods Two operators (1 and 2) independently measured Ko in three groups (keratoconus, normal, and post-CXL corneas), and repeated the procedure in some where their care remained unchanged and others after routine CXL (>28 days postop, epi-off treatment, 3.0 mW/cm2, 30 min). The data were subsequently used to quantify interoperator error, test-retest/intersessional reliability for estimation of Ko, the significance of intergroup differences, and the effect of CXL on Ko. Results The major findings were: (i) Ko values were not normally distributed; (ii) mean (±sd, 95% CI) interoperator error was -0.002 (±0.019, −0.006 to 0.003, n = 95) and the limit of agreement between the operators was ±0.039; (iii) RMS differences in the intersessional estimation of Ko values were 0.011 (operator 1) and 0.012 (operator 2); (iv) intergroup differences in Ko were not significant (p > 0.05); (v) intersessional change in Ko (y) was linearly related to Ko estimated (x) at 1st session (for operator 2 y = 1.187x−0.021, r = 0.755, n = 16, p < 0.01); and (vi) change in Ko (y1) after CXL was linearly related to Ko (x1) at preop (for operator 2 y1 = 0.880x1−0.016, r = 0.935, n = 20, p < 0.01). Conclusion Friedenwald's technique for estimating the Ko is prone to substantial interoperator error and intersessional differences. According to the technique, the change in Ko following CXL is on par with the expected intersessional change observed in controls.
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Asena BS, Kaskaloglu M. The utility of contact lens-assisted corneal cross-linking (CACXL) in progressive keratoconus patients with thin corneas. Eur J Ophthalmol 2022; 32:11206721211070915. [PMID: 35001701 DOI: 10.1177/11206721211070915] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
PURPOSE To evaluate efficacy and safety of contact lens-assisted corneal cross-linking (CACXL) among progressive keratoconus patients with thin corneas. SETTING Private eye hospital. DESIGN Cross-sectional study. METHODS Thirty-six eyes of 36 consecutive patients with progressive keratoconus and thinnest corneal thickness of 380-400 µm after epithelium removal were included. CACXL was performed based on use of a dextran-free isotonic (>0.1%) riboflavin solution with hydroxypropyl methylcellulose (HPMC, 1.1%) after epithelial removal and placement of a riboflavin-soaked contact lens without an ultraviolet filter on the cornea and ultraviolet irradiance. Data on best distance corrected (CDVA) and uncorrected (UDVA) visual acuity, manifest sphere (D), manifest cylinder (D), K1 (D), K2 (D), mean keratometry (D) and Kmax (D) values, endothelial cell count and mean depth of demarcation line were recorded preoperatively and at the postoperative 1-year. RESULTS Post-operative 1-year data revealed significant increases in UDVA (0.23 ± 0.15 vs. 0.17 ± 0.13 D, p < 0.001) and CDVA (0.44 ± 0.18 vs. 0.36 ± 0.17 D, p < 0.001) values and a significant reduction in the mean Kmax (from 56 ± 3.3D to 55 ± 3.2 D, p < 0.001), K2 (from 49.7 ± 3.2 D to 49.52 ± 3.11 D, p = 0.049), manifest sphere (from -1.93 ± 2.21 D to -1.55 ± 2.02 D, p = 0.001) and manifest cylinder (from -2.83 ± 1.67 D to -2.39 ± 1.36 D, p < 0.001) values along with a similar endothelial cell count. The mean depth of demarcation line was mean 230 (SD17.05, range 200 to 262) at postoperative 1-month. CONCLUSIONS Our findings indicate favourable 1-year postoperative outcome of CACXL in progressive keratoconus patients with thin cornea in terms of improved visual acuity and keratectasia status as well as endothelial safety.
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Nour MM, El-Agha MSH, Sherif AM, Shousha SM. Efficacy and Safety of Contact Lens-Assisted Corneal Crosslinking in the Treatment of Keratoconus With Thin Corneas. Eye Contact Lens 2021; 47:500-504. [PMID: 34001713 DOI: 10.1097/icl.0000000000000799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the safety and efficacy of contact lens-assisted crosslinking (CA-CXL) in progressive keratoconus with thin corneas (350-400 µm). METHODS Forty eyes (30 patients) underwent epithelium-off CA-CXL with iso-osmolar riboflavin and ultraviolet-A irradiation for 30 min (fluence, 3 mW/cm2). A non-ultra-violet-absorbing soft contact lens (sCL) soaked in riboflavin was applied over the cornea during irradiation. Demarcation line (DL) depth was measured 1 month postoperatively. Endothelial cell count (ECC) was measured preoperatively and 3 months postoperatively. Distance uncorrected visual acuity (UDVA) and best spectacle-corrected visual acuity (BDVA), and maximum keratometric values (K max) were evaluated preoperatively and 9 months postoperatively. RESULTS The sCL added a mean thickness of 100.05±1.23 µm. The mean ECC was 2,982±165 cell/mm2 preoperatively and 2,955±125 cell/mm2 postoperatively (endothelial cell loss, 0.9%, P=0.21). The mean DL depth was 204.8±20.2 µm. There was significant improvement in UDVA (P<0.001) and BDVA (P=0.011) with a stable K max (P=0.06). CONCLUSION Contact lens-assisted crosslinking was safe and effective, with endothelial loss less than 1% after 3 months and stable corneal tomography over 9 months, with improved visual acuity. Demarcation line depth was found to be shallower than conventional CXL. Therefore, the long-term efficacy of CA-CXL requires further study. CLINICAL TRIAL REGISTRY NUMBER NCT04504578 Clinical trials.gov.
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Wu D, Lim DKA, Lim BXH, Wong N, Hafezi F, Manotosh R, Lim CHL. Corneal Cross-Linking: The Evolution of Treatment for Corneal Diseases. Front Pharmacol 2021; 12:686630. [PMID: 34349648 PMCID: PMC8326410 DOI: 10.3389/fphar.2021.686630] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 07/05/2021] [Indexed: 01/31/2023] Open
Abstract
Corneal cross-linking (CXL) using riboflavin and ultraviolet A (UVA) light has become a useful treatment option for not only corneal ectasias, such as keratoconus, but also a number of other corneal diseases. Riboflavin is a photoactivated chromophore that plays an integral role in facilitating collagen crosslinking. Modifications to its formulation and administration have been proposed to overcome shortcomings of the original epithelium-off Dresden CXL protocol and increase its applicability across various clinical scenarios. Hypoosmolar riboflavin formulations have been used to artificially thicken thin corneas prior to cross-linking to mitigate safety concerns regarding the corneal endothelium, whereas hyperosmolar formulations have been used to reduce corneal oedema when treating bullous keratopathy. Transepithelial protocols incorporate supplementary topical medications such as tetracaine, benzalkonium chloride, ethylenediaminetetraacetic acid and trometamol to disrupt the corneal epithelium and improve corneal penetration of riboflavin. Further assistive techniques include use of iontophoresis and other wearable adjuncts to facilitate epithelium-on riboflavin administration. Recent advances include, Photoactivated Chromophore for Keratitis-Corneal Cross-linking (PACK-CXL) for treatment of infectious keratitis, customised protocols (CurV) utilising riboflavin coupled with customised UVA shapes to induce targeted stiffening have further induced interest in the field. This review aims to examine the latest advances in riboflavin and UVA administration, and their efficacy and safety in treating a range of corneal diseases. With such diverse riboflavin delivery options, CXL is well primed to complement the armamentarium of therapeutic options available for the treatment of a variety of corneal diseases.
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Affiliation(s)
- Duoduo Wu
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Dawn Ka-Ann Lim
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Ophthalmology, National University Health System, Singapore, Singapore
| | - Blanche Xiao Hong Lim
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Ophthalmology, National University Health System, Singapore, Singapore
| | - Nathan Wong
- Royal Victorian Eye Hospital, Melbourne, VIC, Australia
| | - Farhad Hafezi
- Ocular Cell Biology Group, Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland.,ELZA Institute, Dietikon, Switzerland.,Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Ophthalmology, USC Roski Eye Institute, Los Angeles, CA, United States.,Ophthalmology, Wenzhou Medical University, Wenzhou, China
| | - Ray Manotosh
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Ophthalmology, National University Health System, Singapore, Singapore
| | - Chris Hong Long Lim
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Ophthalmology, National University Health System, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
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Comparison of Contact Lens Assisted and Transepithelial Corneal Cross Linking with Standard 'Epithelium Off' Cross Linking for Progressive Keratoconus: 24 Month Clinical Results. J Cataract Refract Surg 2021; 48:199-207. [PMID: 34174043 DOI: 10.1097/j.jcrs.0000000000000732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 06/14/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE To compare outcomes of contact lens assisted corneal cross linking (CACXL) and transepithelial corneal cross linking (TECXL) with standard 'epithelium off'' ('epi -off') cross linking (CXL) for progressive keratoconus. SETTING Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh , India. DESIGN Retrospective, comparative study. METHODS Patients with progressive keratoconus undergoing CXL with a minimum follow up of 24 months were included. CACXL and TECXL was performed in patients with 'epithelium on' minimal pachymetry between 350 µm to 450 µm. Main outcome measures included change in maximum keratometry (Kmax), corrected distance visual acuity (CDVA), and efficacy in halting progression (increase in Kmax ≥ 1 diopter [D]). RESULTS Standard 'epi -off' CXL, CACXL and TECXL was performed in 34,14 and 10 eyes respectively. Baseline Kmax and CDVA were comparable for all groupsKmax reduced significantly by -2.83 ± 3.35 D, -3.18 ± 2.74D and -2.02 ± 1.66 D in standard 'epi-off' CXL (p<0.01), CACXL (p=0.001) and TECXL (p=0.004) groups respectively; the reduction was comparable for all groups (p=0.63). CDVA improved by -0.14 ± 0.24 , -0.04 ± 0.19 and -0.12 ± 0.17 logMAR units in the standard 'epi -off' CXL (p =0.006), CACXL (p=0.42) and TECXL (p=0.05) groups respectively; the reduction was comparable for all groups (p=0.46). Progression was documented in 2 eyes (6%) of the standard 'epi -off' CXL group and 0% eyes of the CACXL and TECXL groups (p=0.61). CONCLUSIONS CACXL and TECXL were comparable to standard 'epi -off' CXL for progressive keratoconus.
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Srivatsa S, Jacob S, Agarwal A. Contact lens assisted corneal cross linking in thin ectatic corneas - A review. Indian J Ophthalmol 2021; 68:2773-2778. [PMID: 33229652 PMCID: PMC7856986 DOI: 10.4103/ijo.ijo_2138_20] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Contact lens-assisted corneal cross-linking (CACXL) was introduced by Jacob et al. in 2012 for treating thin keratoconic corneas using riboflavin soaked soft contact lens to artificially increase the functional corneal thickness. It is advantageous over other thin corneal cross-linking techniques as it works independent of swelling properties of the cornea, is an epi-off technique and does not require additional time, additional expensive equipments or special solutions. The only additional requirement as compared to all other techniques is a UV barrier-free soft contact lens (Soflens™, B&L) which is easily available and inexpensive. Advantages include simplicity, easy adaptability, early visual rehabilitation, good visual outcomes, safety, and efficacy. Progression rates are acceptable and the need for re-treatment has been low. CACXL can help regularize corneal shape and may be used in isolation or synergistically with Intracorneal ring segments (ICRS) or Corneal allogenic intrastromal ring segments (CAIRS). It gives about 70% stiffening as compared to standard Dresden protocol CXL in less ideal porcine eye studies. Murine eye models that closely mimic thin corneas and show greater cross-linking effect as compared to porcine eyes may be a better model for evaluation of CACXL, however further studies are needed. Care should be taken in selecting the right kind of contact lens. Proper technique should be followed, especially by confirming thinnest functional pachymetry to be above 400 microns intra-operatively before application of UV-A. The sub-contact lens riboflavin film should be avoided as also an excessively thick supra-contact lens riboflavin film and too many re-applications.
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Affiliation(s)
- Sanjana Srivatsa
- Cornea and Refractive Servives, Dr. Agarwal's Eye Hospital and Research Centre, Chennai, Tamil Nadu, India
| | - Soosan Jacob
- Cornea and Refractive Servives, Dr. Agarwal's Eye Hospital and Research Centre; Cornea, Refractive and Cataract Services, Dr. Agarwal's Refractive and Cornea Foundation, Chennai, Tamil Nadu, India
| | - Amar Agarwal
- Cornea and Refractive Servives, Dr. Agarwal's Eye Hospital and Research Centre, Chennai, Tamil Nadu, India
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Hafezi F, Kling S, Gilardoni F, Hafezi N, Hillen M, Abrishamchi R, Gomes JAP, Mazzotta C, Randleman JB, Torres-Netto EA. Individualized Corneal Cross-linking With Riboflavin and UV-A in Ultrathin Corneas: The Sub400 Protocol. Am J Ophthalmol 2021; 224:133-142. [PMID: 33340508 DOI: 10.1016/j.ajo.2020.12.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 11/30/2022]
Abstract
PURPOSE To determine whether corneal cross-linking (CXL) with individualized fluence ("sub400 protocol") is able to stop keratoconus (KC) progression in ultrathin corneas with 12-month follow-up. DESIGN Retrospective, interventional case series. METHODS Thirty-nine eyes with progressive KC and corneal stromal thicknesses from 214 to 398 μm at the time of ultraviolet irradiation were enrolled. After epithelium removal, ultraviolet irradiation was performed at 3 mW/cm2 with irradiation times individually adapted to stromal thickness. Pre- and postoperative examinations included corrected distance visual acuity (CDVA), refraction, Scheimpflug, and anterior segment optical coherence tomography imaging up to 12 months after CXL. Outcome measures were arrest of KC progression at 12 months postoperatively and stromal demarcation line (DL) depth. RESULTS Thirty-five eyes (90%) showed tomographical stability at 12 months after surgery. No eyes showed signs of endothelial decompensation. A significant correlation was found between DL depth and irradiation time (r = +0.448, P = .004) but not between DL depth and change in Kmax (r = -0.215, P = .189). On average, there was a significant change (P < .05) in thinnest stromal thickness (-14.5 ± 21.7 μm), Kmax (-2.06 ± 3.66 D) and densitometry (+2.00 ± 2.07 GSU). No significant changes were found in CDVA (P = .611), sphere (P = .077), or cylinder (P = .915). CONCLUSIONS The "sub400" individualized fluence CXL protocol standardizes the treatment in ultrathin corneas and halted KC progression with a success rate of 90% at 12 months. The sub400 protocol allows for the treatment of corneas as thin as 214 μm of corneal stroma, markedly extending the treatment range. The DL depth did not predict treatment outcome. Hence, the depth is unlikely related to the extent of CXL-induced corneal stiffening but rather to the extent of CXL-induced microstructural changes and wound healing.
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Affiliation(s)
- Farhad Hafezi
- Laboratory for Ocular Cell Biology, Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland; Department of Ophthalmology, ELZA Institute, Dietikon, Switzerland; Department of Ophthalmology, USC Roski Eye Institute, University of Southern California, Los Angeles, California, USA; Faculty of Medicine, University of Geneva, Geneva, Switzerland; Department of Ophthalmology, University of Wenzhou, Wenzhou, China.
| | - Sabine Kling
- Department of Information Technology and Electrical Engineering, Swiss Federal Institute of Technology Zurich, Zürich, Switzerland
| | - Francesca Gilardoni
- Laboratory for Ocular Cell Biology, Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland; Department of Ophthalmology, ELZA Institute, Dietikon, Switzerland
| | - Nikki Hafezi
- Department of Ophthalmology, ELZA Institute, Dietikon, Switzerland
| | - Mark Hillen
- Department of Ophthalmology, ELZA Institute, Dietikon, Switzerland
| | - Reyhaneh Abrishamchi
- Laboratory for Ocular Cell Biology, Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland; Department of Ophthalmology, ELZA Institute, Dietikon, Switzerland
| | - Jose Alvaro P Gomes
- Laboratory for Ocular Cell Biology, Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland; Department of Ophthalmology, Paulista School of Medicine, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Cosimo Mazzotta
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy; Department of Ophthalmology, Siena Crosslinking Center, Siena, Italy
| | - J Bradley Randleman
- Department of Ophthalmology, The Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Emilio A Torres-Netto
- Laboratory for Ocular Cell Biology, Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland; Department of Ophthalmology, ELZA Institute, Dietikon, Switzerland; Department of Ophthalmology, Paulista School of Medicine, Federal University of Sao Paulo, Sao Paulo, Brazil; Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Hayes S, Morgan SR, Meek KM. Keratoconus: cross-linking the window of the eye. THERAPEUTIC ADVANCES IN RARE DISEASE 2021; 2:26330040211003573. [PMID: 37181107 PMCID: PMC10032441 DOI: 10.1177/26330040211003573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 02/25/2021] [Indexed: 05/16/2023]
Abstract
Keratoconus is a condition in which the cornea progressively thins and weakens, leading to severe, irregular astigmatism and a significant reduction in quality of life. Although the precise cause of keratoconus is still not known, biochemical and structural studies indicate that overactive enzymes within the cornea break down the constituent proteins (collagen and proteoglycans) and cause the tissue to weaken. As the disease develops, collagen fibres slip past each other and are redistributed across the cornea, causing it to change shape. In recent years, it was discovered that the photochemical induction of cross-links within the corneal extracellular matrix, through the use of riboflavin and ultraviolet (UVA) light, could increase the strength and enzymatic resistance of the tissue and thereby halt keratoconus progression. Worldwide acceptance and use of riboflavin/UVA corneal cross-linking therapy for halting keratoconus progression has increased rapidly, in accordance with the growing body of evidence supporting its long-term effectiveness. This review focusses on the inception of riboflavin/UVA corneal cross-linking therapy for keratoconus, its clinical effectiveness and the latest scientific advances aimed at reducing patient treatment time, improving patient comfort and increasing patient eligibility for treatment. Plain language summary Review of current treatments using cross-linking to halt the progress of keratoconus Keratoconus is a disease in which the curved cornea, the transparent window at the front of the eye, weakens, bulges forward into a cone-shape and becomes thinner. This change of curvature means that light is not focussed onto the retina correctly and vision is progressively impaired. Traditionally, the effects of early keratoconus were alleviated by using glasses, specialist contact lenses, rings inserted into the cornea and in severe cases, by performing a corneal transplant. However, it was discovered that by inducing chemical bonds called cross-links within the cornea, the tissue could be strengthened and further thinning and shape changes prevented. The standard cross-linking procedure takes over an hour to perform and involves the removal of the cells at the front of the cornea, followed by the application of Vitamin B2 eye drops and low energy ultraviolet light (UVA) to create new cross-links within the tissue. Clinical trials have shown this standard procedure to be safe and effective at halting keratoconus progression. However, there are many treatment modifications currently under investigation that aim to reduce patient treatment time and increase comfort, such as accelerated cross-linking procedures and protocols that do not require removal of the surface cells. This review describes the different techniques being developed to carry out corneal cross-linking efficiently and painlessly, to halt keratoconus progression and avoid the need for expensive surgery.
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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
| | - Siân R Morgan
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - Keith M Meek
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
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Toffoletto N, Saramago B, Serro AP. Therapeutic Ophthalmic Lenses: A Review. Pharmaceutics 2020; 13:36. [PMID: 33379411 PMCID: PMC7824655 DOI: 10.3390/pharmaceutics13010036] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/09/2020] [Accepted: 12/17/2020] [Indexed: 12/17/2022] Open
Abstract
An increasing incidence of eye diseases has been registered in the last decades in developed countries due to the ageing of population, changes in lifestyle, environmental factors, and the presence of concomitant medical conditions. The increase of public awareness on ocular conditions leads to an early diagnosis and treatment, as well as an increased demand for more effective and minimally invasive solutions for the treatment of both the anterior and posterior segments of the eye. Despite being the most common route of ophthalmic drug administration, eye drops are associated with compliance issues, drug wastage by lacrimation, and low bioavailability due to the ocular barriers. In order to overcome these problems, the design of drug-eluting ophthalmic lenses constitutes a non-invasive and patient-friendly approach for the sustained drug delivery to the eye. Several examples of therapeutic contact lenses and intraocular lenses have been developed, by means of different strategies of drug loading, leading to promising results. This review aims to report the recent advances in the development of therapeutic ophthalmic lenses for the treatment and/or prophylaxis of eye pathologies (i.e., glaucoma, cataract, corneal diseases, or posterior segment diseases) and it gives an overview of the future perspectives and challenges in the field.
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Affiliation(s)
- Nadia Toffoletto
- Centro de Química Estrutural, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; (B.S.); (A.P.S.)
| | - Benilde Saramago
- Centro de Química Estrutural, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; (B.S.); (A.P.S.)
| | - Ana Paula Serro
- Centro de Química Estrutural, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; (B.S.); (A.P.S.)
- Centro de Investigação Interdisciplinar Egas Moniz, Instituto Universitário Egas Moniz, Quinta da Granja, Monte de Caparica, 2829-511 Caparica, Portugal
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Crosslinking of Thin Corneas: a Modern Vision of the Problem. Literature Review. ACTA BIOMEDICA SCIENTIFICA 2020. [DOI: 10.29413/abs.2020-5.5.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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An Assay System to Evaluate Riboflavin/UV-A Corneal Phototherapy Efficacy in a Porcine Corneal Organ Culture Model. Animals (Basel) 2020; 10:ani10040730. [PMID: 32340101 PMCID: PMC7652214 DOI: 10.3390/ani10040730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 04/16/2020] [Accepted: 04/19/2020] [Indexed: 12/21/2022] Open
Abstract
Simple summary The scope of this study is to quantitatively evaluate, with an automated digital image analysis method, the efficacy of riboflavin/UV-A corneal phototherapy on the cornea in a porcine corneal organ culture model of ulcerative melting keratitis. Riboflavin/UV-A corneal phototherapy provided a favorable outcome in the corneal wound healing process after chemical injury: the treatment restores the damaged corneas to the texture of healthy corneas. This automated image analysis method may be compared to clinical diagnostic methods, such as optical coherence tomography (OCT) imaging, for in vivo damaged ocular structural investigations. Positive results from this research could provide an opportunity for studying the effects of this method in other economically and emotionally valued species, such as dogs, cats, and horses. The relatively overall low treatment cost and the ease of performing the procedure make riboflavin/UV-A corneal phototherapy accessible to the veterinary market. Abstract The purpose of this study was to investigate the response of porcine corneal organ cultures to riboflavin/UV-A phototherapy in the injury healing of induced lesions. A porcine corneal organ culture model was established. Corneal alterations in the stroma were evaluated using an assay system, based on an automated image analysis method able to (i) localize the holes and gaps within the stroma and (ii) measure the brightness values in these patches. The analysis has been performed by dividing the corneal section in 24 regions of interest (ROIs) and integrating the data analysis with a “multi-aspect approach.” Three group of corneas were analyzed: healthy, injured, and injured-and-treated. Our study revealed a significant effect of the riboflavin/UV-A phototherapy in the injury healing of porcine corneas after induced lesions. The injured corneas had significant differences of brightness values in comparison to treated (p < 0.00) and healthy (p < 0.001) corneas, whereas the treated and healthy corneas showed no significant difference (p = 0.995). Riboflavin/UV-A phototherapy shows a significant effect in restoring the brightness values of damaged corneas to the values of healthy corneas, suggesting treatment restores the injury healing of corneas after lesions. Our assay system may be compared to clinical diagnostic methods, such as optical coherence tomography (OCT) imaging, for in vivo damaged ocular structure investigations.
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Zhang H, Roozbahani M, Piccinini AL, Golan O, Hafezi F, Scarcelli G, Randleman JB. Depth-Dependent Reduction of Biomechanical Efficacy of Contact Lens-Assisted Corneal Cross-linking Analyzed by Brillouin Microscopy. J Refract Surg 2019; 35:721-728. [PMID: 31710374 PMCID: PMC7767636 DOI: 10.3928/1081597x-20191004-01] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 10/04/2019] [Indexed: 01/08/2023]
Abstract
PURPOSE To determine the relative impact of contact lens- assisted corneal cross-linking (CACXL) and standard protocol CXL (CXL) on regional corneal stiffness using Brillouin microscopy. METHODS CXL and CACXL were performed on 30 intact fresh porcine eyes (15 per group). Depth profile of stiffness variation and averaged elastic modulus of anterior, middle, and posterior stroma were determined by Brillouin maps. Corneas were cut into strips to conduct mechanical stress-strain tests after Brillouin microscopy to evaluate stiffness difference between CXL and CACXL. Each eye served as its own control. RESULTS CXL had a greater impact on corneal stiffness, with a maximum increase of 5.74% compared to 3.99% for CACXL (P < .001). CXL increased longitudinal modulus by 7.8% in the anterior, 1.7% in the middle, and -0.7% in the posterior regions compared to CACXL, which increased longitudinal modulus by 5.5% in the anterior (P < .001), 1.2% in the middle (P = .15), and -0.4% in the posterior regions (P = .60). Mechanical stress-strain tests showed that at 10% strain averaged Young's modulus was 5 MPa for CXL and 2.97 MPa for CACXL (P < .001). CONCLUSIONS Both CACXL and standard protocol CXL induced significant corneal stiffening primarily concentrated in the anterior cornea. CACXL leads to less stiffening compared with CXL. An attenuated but continuous stiffening effect can be observed through the whole cornea for both CACXL and CXL, although CACXL has a smaller stiffness gradient. [J Refract Surg. 2019;35(11):721-728.].
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Dzobo K, Motaung KSCM, Adesida A. Recent Trends in Decellularized Extracellular Matrix Bioinks for 3D Printing: An Updated Review. Int J Mol Sci 2019; 20:E4628. [PMID: 31540457 PMCID: PMC6788195 DOI: 10.3390/ijms20184628] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 09/01/2019] [Accepted: 09/12/2019] [Indexed: 02/06/2023] Open
Abstract
The promise of regenerative medicine and tissue engineering is founded on the ability to regenerate diseased or damaged tissues and organs into functional tissues and organs or the creation of new tissues and organs altogether. In theory, damaged and diseased tissues and organs can be regenerated or created using different configurations and combinations of extracellular matrix (ECM), cells, and inductive biomolecules. Regenerative medicine and tissue engineering can allow the improvement of patients' quality of life through availing novel treatment options. The coupling of regenerative medicine and tissue engineering with 3D printing, big data, and computational algorithms is revolutionizing the treatment of patients in a huge way. 3D bioprinting allows the proper placement of cells and ECMs, allowing the recapitulation of native microenvironments of tissues and organs. 3D bioprinting utilizes different bioinks made up of different formulations of ECM/biomaterials, biomolecules, and even cells. The choice of the bioink used during 3D bioprinting is very important as properties such as printability, compatibility, and physical strength influence the final construct printed. The extracellular matrix (ECM) provides both physical and mechanical microenvironment needed by cells to survive and proliferate. Decellularized ECM bioink contains biochemical cues from the original native ECM and also the right proportions of ECM proteins. Different techniques and characterization methods are used to derive bioinks from several tissues and organs and to evaluate their quality. This review discusses the uses of decellularized ECM bioinks and argues that they represent the most biomimetic bioinks available. In addition, we briefly discuss some polymer-based bioinks utilized in 3D bioprinting.
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Affiliation(s)
- Kevin Dzobo
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cape Town Component, Wernher and Beit Building (South), UCT Medical Campus, Anzio Road, Observatory, Cape Town 7925, South Africa.
- Division of Medical Biochemistry and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Anzio Road, Observatory, Cape Town 7925, South Africa.
| | | | - Adetola Adesida
- Department of Surgery, Faculty of Medicine and Dentistry, Li Ka Shing Centre for Health Research Innovation, University of Alberta, Edmonton, AB T6G 2E1, Canada.
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