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Khan M, Michelson S, Newman-Casey PA, Woodward MA. Medication Adherence Among Patients With Corneal Diseases. Cornea 2021; 40:1554-1560. [PMID: 33661137 PMCID: PMC8418623 DOI: 10.1097/ico.0000000000002680] [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: 10/20/2020] [Accepted: 12/26/2020] [Indexed: 11/27/2022]
Abstract
PURPOSE Medication nonadherence is a ubiquitous problem. However, the adherence of patients to medications to manage corneal conditions is unknown. A prospective cohort study investigated the patterns of eye drop adherence among patients with corneal conditions. METHODS Patients older than or equal to 18 years taking prescription eye medications were recruited from an academic center's corneal clinic. Data collected included age, sex, total doses of eye medications, and category of primary corneal diagnosis. Participants completed adapted versions of the 12-question Adherence to Refills and Medications Scale (ARMS) and the 3-question Voils' Medication Adherence Scale (VMAS). Survey data were dichotomized as "adherent" and "nonadherent," and subscales reported for reasons of nonadherence. Logistic regression analyses were used to test associations with adherence. RESULTS A total of 199 participants were surveyed from February to March 2019 (95% response rate). Participants were aged 19 to 93 years with a mean age of 59 years (SD 17.8). The percent of participants considered nonadherent was 72% by the ARMS and 33% by the VMAS. Older age was associated with higher adherence by the ARMS (odds ratio = 1.48, 95% confidence interval, 1.14-1.93, P = 0.004) and by the VMAS (odds ratio = 1.24, confidence interval, 1.04-1.48, P = 0.012). Adherence was not significantly associated with race, sex, education, total doses of eye medications, or primary cornea diagnosis. CONCLUSIONS Medication adherence was lower than expected, particularly on the ARMS scale that asks more detailed questions. Clinicians should engage in conversations about adherence, especially with younger patients, if they are not seeing an expected clinical response.
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Affiliation(s)
- Mariam Khan
- Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan
| | - Sarah Michelson
- Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan
| | - Paula Anne Newman-Casey
- Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan
- Institute for Healthcare Policy and Innovation, University of Michigan, Ann Arbor, Michigan
| | - Maria A. Woodward
- Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan
- Institute for Healthcare Policy and Innovation, University of Michigan, Ann Arbor, Michigan
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2
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Baird PN, Machin H, Brown KD. Corneal supply and the use of technology to reduce its demand: A review. Clin Exp Ophthalmol 2021; 49:1078-1090. [PMID: 34310836 DOI: 10.1111/ceo.13978] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 11/26/2022]
Abstract
Recovery and access to end-of-life corneal tissue for corneal transplantation, training and research is globally maldistributed. The reasons for the maldistribution are complex and multifaceted, and not well defined or understood. Currently there are few solutions available to effectively address these issues. This review provides an overview of the system, key issues impacting recovery and allocation and emphasises how end-user ophthalmologists and researchers, with support from administrators and the wider sector, can assist in increasing access long-term through sustaining eye banks nationally and globally. We posit that prevention measures and improved surgical techniques, together with the development of novel therapies will play a significant role in reducing demand and enhance the equitable allocation of corneas.
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Affiliation(s)
- Paul N Baird
- Department of Surgery, Ophthalmology, University of Melbourne, Melbourne, Victoria, Australia
| | - Heather Machin
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
- Lions Eye Donation Service, Melbourne, Australia
| | - Karl D Brown
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
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3
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Elsawy A, Eleiwa T, Chase C, Ozcan E, Tolba M, Feuer W, Abdel-Mottaleb M, Abou Shousha M. Multidisease Deep Learning Neural Network for the Diagnosis of Corneal Diseases. Am J Ophthalmol 2021; 226:252-261. [PMID: 33529589 DOI: 10.1016/j.ajo.2021.01.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 01/19/2021] [Accepted: 01/25/2021] [Indexed: 01/12/2023]
Abstract
PURPOSE To report a multidisease deep learning diagnostic network (MDDN) of common corneal diseases: dry eye syndrome (DES), Fuchs endothelial dystrophy (FED), and keratoconus (KCN) using anterior segment optical coherence tomography (AS-OCT) images. STUDY DESIGN Development of a deep learning neural network diagnosis algorithm. METHODS A total of 158,220 AS-OCT images from 879 eyes of 478 subjects were used to develop and validate a classification deep network. After a quality check, the network was trained and validated using 134,460 images. We tested the network using a test set of consecutive patients involving 23,760 AS-OCT images of 132 eyes of 69 patients. The area under receiver operating characteristic curve (AUROC), area under precision-recall curve (AUPRC), and F1 score and 95% confidence intervals (CIs) were computed. RESULTS The MDDN achieved eye-level AUROCs >0.99 (95% CI: 0.90, 1.0), AUPRCs > 0.96 (95% CI: 0.90, 1.0), and F1 scores > 0.90 (95% CI: 0.81, 1.0) for DES, FED, and KCN, respectively. CONCLUSIONS MDDN is a novel diagnostic tool for corneal diseases that can be used to automatically diagnose KCN, FED, and DES using only AS-OCT images.
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Affiliation(s)
- Amr Elsawy
- Bascom Palmer Eye institute, Miller School of Medicine, University of Miami, Miami; Electrical and Computer Engineering, University of Miami, Coral Gables
| | - Taher Eleiwa
- Bascom Palmer Eye institute, Miller School of Medicine, University of Miami, Miami; Department of Ophthalmology, Faculty of Medicine, Benha University, Egypt
| | - Collin Chase
- Bascom Palmer Eye institute, Miller School of Medicine, University of Miami, Miami
| | - Eyup Ozcan
- Bascom Palmer Eye institute, Miller School of Medicine, University of Miami, Miami; Net Eye Medical Center, Gaziantep, Turkey
| | - Mohamed Tolba
- Bascom Palmer Eye institute, Miller School of Medicine, University of Miami, Miami
| | - William Feuer
- Bascom Palmer Eye institute, Miller School of Medicine, University of Miami, Miami
| | | | - Mohamed Abou Shousha
- Bascom Palmer Eye institute, Miller School of Medicine, University of Miami, Miami; Electrical and Computer Engineering, University of Miami, Coral Gables; Biomedical Engineering, University of Miami, Coral Gables, Florida, USA.
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4
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Abdelaal AM, Alqassimi AH, Malak M, Hijazi HT, Hadrawi M, Khan MA. Indications of Keratoplasty and Outcomes of Deep Anterior Lamellar Keratoplasty Compared to Penetrating Keratoplasty. Cureus 2021; 13:e13825. [PMID: 33859889 PMCID: PMC8040744 DOI: 10.7759/cureus.13825] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background Corneal diseases are a significant cause of visual impairment and blindness. Despite the treatable nature of many corneal diseases before visual demise, many cases of advanced disease necessitating keratoplasty for visual rehabilitation are encountered. A mismatch between the number of corneal donors and potential recipients also exists worldwide, with underutilization of certain types of keratoplasty techniques that may allow more efficient use of this limited resource. Methodology A retrospective cohort study of all cases of optical corneal transplantations performed from January 1, 2015 to October 31, 2020 was performed. Indications for keratoplasty, type of keratoplasty, complications, intraocular pressure elevation, and best corrected visual acuity (BCVA) by category and range at different time intervals were collected and analyzed. Findings were compared between penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) for all indications, specifically for keratoconus (KCN). Results A total of 58 corneal transplants meeting our criteria were performed during the study period. PK was performed for 29 eyes, DALK for 28 eyes, and endothelial keratoplasty for one eye. The most frequently encountered indication was KCN (62.1%). The number of eyes with BCVA of 20/100 or better increased from preoperative BCVA, 37/58 eyes had BCVA worse than 20/100 before keratoplasty (63.8%), while at the time of last follow-up 45/58 eyes had BCVA of 20/100 or better (77.6%). At the time of last follow-up 16/58 had BCVA in the range of 20/20 to 20/40 (27.6%) and 29/58 eyes had BCVA in the range of 20/50 to 20/100 (50%). Comparison of all cases of PK to DALK for all indications showed significantly better BCVA by category at one year, at last follow-up, and BCVA range at last follow-up (p = 0.032, 0.001, and 0.014, respectively). Although better visual acuity results by category and range at one year and last follow-up, respectively, were observed in more patients undergoing DALK than PK, for KCN the results were not statistically significant (p = 1.00, 1.00, 0.417, and 0.374, respectively). Overall, 70% of recorded complications, intraocular pressure (IOP) elevations, and graft rejections were seen in eyes that underwent PK; however, these findings were not statistically significant (p = 0.297). Graft failures occurred more frequently with PK than deep anterior keratoplasty when analyzed for all indications of keratoplasty (p = 0.010). Conclusions Despite advancement and improvements in surgical techniques, statistics continue to show underutilization of the invaluable resource of donor corneas, with PK still being performed more than DALK for diseases that do not affect the endothelium. Our study found superior visual acuity outcomes of DALK as well as the advantages of less frequent complications, IOP elevations, graft rejections, and graft failures. We encourage ophthalmologists to utilize DALK in appropriate candidates to more fully utilize the scarce and potentially vision-restoring resource of donor corneal tissue.
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Affiliation(s)
- Ahmed M Abdelaal
- Surgery/Ophthalmology, King Saud Bin Abdulaziz University for Health Sciences/King Abdulaziz Medical City - Ministry of National Guard Health Affairs, Jeddah, SAU.,College of Medicine, Alfaisal University, Riyadh, SAU
| | - Albaraa H Alqassimi
- Department of Ophthalmology/Cornea and Anterior Segment Consultant, King Fahad Armed Forces Hospital, Jeddah, SAU
| | - Mohammad Malak
- Department of Ophthalmology/Cornea and Anterior Segment Consultant, King Fahad Armed Forces Hospital, Jeddah, SAU
| | - Hassan T Hijazi
- Department of Ophthalmology/Ophthalmologist, King Fahad Armed Forces Hospital, Jeddah, SAU
| | - Manal Hadrawi
- Department of Ophthalmology/Pediatric Ophthalmology and Strabismology Consultant, King Fahad Armed Forces Hospital, Jeddah, SAU
| | - Muhammad A Khan
- Medical Education, King Saud Bin Abdulaziz University for Health Sciences, Jeddah, SAU
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Park J, Lee K, Kim H, Park S, Wijesinghe RE, Lee J, Han S, Lee S, Kim P, Cho D, Jang J, Kim HK, Jeon M, Kim J. Biocompatibility evaluation of bioprinted decellularized collagen sheet implanted in vivo cornea using swept-source optical coherence tomography. JOURNAL OF BIOPHOTONICS 2019; 12:e201900098. [PMID: 31240872 PMCID: PMC7065634 DOI: 10.1002/jbio.201900098] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 05/26/2019] [Accepted: 06/25/2019] [Indexed: 05/04/2023]
Abstract
Corneal transplantation by full-thickness penetrating keratoplasty with human donor tissue is a widely accepted treatment for damaged or diseased corneas. Although corneal transplantation has a high success rate, a shortage of high-quality donor tissue is a considerable limitation. Therefore, bioengineered corneas could be an effective solution for this limitation, and a decellularized extracellular matrix comprises a promising scaffold for their fabrication. In this study, three-dimensional bioprinted decellularized collagen sheets were implanted into the stromal layer of the cornea of five rabbits. We performed in vivo noninvasive monitoring of the rabbit corneas using swept-source optical coherence tomography (OCT) after implanting the collagen sheets. Anterior segment OCT images and averaged amplitude-scans were acquired biweekly to monitor corneal thickness after implantation for 1 month. The averaged cornea thickness in the control images was 430.3 ± 5.9 μm, while the averaged thickness after corneal implantation was 598.5 ± 11.8 μm and 564.5 ± 12.5 μm at 2 and 4 weeks, respectively. The corneal thickness reduction of 34 μm confirmed the biocompatibility through the image analysis of the depth-intensity profile base. Moreover, hematoxylin and eosin staining supported the biocompatibility evaluation of the bioprinted decellularized collagen sheet implantation. Hence, the developed bioprinted decellularized collagen sheets could become an alternative solution to human corneal donor tissue, and the proposed image analysis procedure could be beneficial to confirm the success of the surgery.
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Affiliation(s)
- Jaeseok Park
- School of Electronic Engineering, College of IT EngineeringKyungpook National UniversityDaeguSouth Korea
| | - Kyoung‐Pil Lee
- Department of Ophthalmology, School of MedicineKyungpook National UniversityDaeguSouth Korea
- Bio‐Medical InstituteKyungpook National University HospitalDaeguSouth Korea
| | - Hyeonji Kim
- Department of Mechanical EngineeringPohang University of Science and TechnologyPohangSouth Korea
| | - Sungjo Park
- Laser Application Center, Institute of Advanced Convergence TechnologyKyungpook National UniversityDaeguSouth Korea
| | - Ruchire E. Wijesinghe
- Department of Biomedical Engineering, College of EngineeringKyungil UniversityGyeongsanSouth Korea
| | - Jaeyul Lee
- School of Electronic Engineering, College of IT EngineeringKyungpook National UniversityDaeguSouth Korea
| | - Sangyeob Han
- School of Electronic Engineering, College of IT EngineeringKyungpook National UniversityDaeguSouth Korea
| | - Sangbong Lee
- School of Electronic Engineering, College of IT EngineeringKyungpook National UniversityDaeguSouth Korea
| | - Pilun Kim
- Institute of Biomedical Engineering, School of MedicineKyungpook National UniversityDaeguSouth Korea
| | - Dong‐Woo Cho
- Department of Mechanical EngineeringPohang University of Science and TechnologyPohangSouth Korea
| | - Jinah Jang
- Department of Creative IT EngineeringPohang University of Science and TechnologyPohangSouth Korea
- School of Interdisciplinary Bioscience and BioengineeringPohang University of Science and TechnologyPohangSouth Korea
| | - Hong K. Kim
- Department of Ophthalmology, School of MedicineKyungpook National UniversityDaeguSouth Korea
- Bio‐Medical InstituteKyungpook National University HospitalDaeguSouth Korea
| | - Mansik Jeon
- School of Electronic Engineering, College of IT EngineeringKyungpook National UniversityDaeguSouth Korea
| | - Jeehyun Kim
- School of Electronic Engineering, College of IT EngineeringKyungpook National UniversityDaeguSouth Korea
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Costa D, Leiva M, Naranjo C, Ríos J, Peña MT. Cryopreservation (-20°C) of equine corneoscleral tissue: Microbiological, histological, and ultrastructural study. Vet Ophthalmol 2019; 22:493-501. [PMID: 30735310 DOI: 10.1111/vop.12618] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 08/25/2018] [Accepted: 08/30/2018] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate microbiological, histological, and ultrastructural characteristics of short-term cryopreserved (STC) equine corneoscleral tissue (<1 year), and to compare it with long-term cryopreserved (LTC) tissue (>7 years). ANIMALS STUDIED Thirty-four healthy equine globes. PROCEDURE After a decontamination protocol, globes were enucleated and stored at -20°C in broad-spectrum antibiotics. Corneoscleral tissue was evaluated at different storage periods: 1 month-1 year (20 eyes) and 7-9 years (12 eyes). Two eyes were used as controls. Microbiologic study included direct (blood, McConkey, and Sabouraud agars) and enrichment (brain-heart infusion broth) cultures. Cryopreservation artifacts were evaluated by hematoxylin-eosin. Corneoscleral collagen organization and number of normal and dead keratocytes were established by transmission electron microscopy. RESULTS All microbiologic direct cultures were negative. Enrichment cultures were positive in 12.5% of corneal and 59.4% of scleral tissues (pcornea = 0.136; psclera = 1.000). Cryopreservation artifacts were most commonly observed in LTC tissues (P = 0.002). Normal keratocytes were predominant in STC corneas (STC 60% and LTC 0%) and apoptotic ones in LTC (STC 40% and LTC 90%), whereas necrotic keratocytes were only seen in LTC (LTC 10%) (P = 0.001). No structural differences were detected in collagen organization between STC and LTC (pcornea = 1.000; psclera = 0.703). CONCLUSIONS Cryopreservation of equine corneoscleral tissue did not yield direct bacterial contamination. Apoptosis is the main cause of death of cryopreserved equine keratocytes. Based on the lack of significant structural differences between STC and LTC samples, these cryopreserved tissues could potentially be used for tectonic support for at least 9 years without structural or microbiological impediment.
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Affiliation(s)
- Daniel Costa
- Servei d'Oftalmologia de la Fundació Hospital Clínic Veterinari, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Marta Leiva
- Servei d'Oftalmologia de la Fundació Hospital Clínic Veterinari, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.,Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | | | - José Ríos
- Facultat de Medicina, Laboratory of Biostatistics & Epidemiology, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.,Biostatistics and Medical Statistics Core Facility, IDIBAPS, Hospital Clínic, Barcelona, Spain
| | - Maria Teresa Peña
- Servei d'Oftalmologia de la Fundació Hospital Clínic Veterinari, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.,Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
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7
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From DMEK to Corneal Endothelial Cell Therapy: Technical and Biological Aspects. J Ophthalmol 2018; 2018:6482095. [PMID: 30155283 PMCID: PMC6093046 DOI: 10.1155/2018/6482095] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 05/13/2018] [Accepted: 06/26/2018] [Indexed: 12/13/2022] Open
Abstract
The main treatment available for restoration of the corneal endothelium is keratoplasty and DMEK provides faster visual recovery and better postoperative visual acuity when compared to DSAEK. However, the technical challenges related to this technique and the steep technical learning curve seem to prevent the overcoming of DSAEK in favor of DMEK. Furthermore, the outcome of lamellar keratoplasty techniques is influenced by problems related to corneal grafting tissue availability, management, and quality. On the other hand, improvements in the field of cell engineering have opened the way for the use of stem cells-derived corneal endothelial cells with regenerative intent. In this overview, latest findings in endothelial cell engineering are reported, and perspectives of clinical application of mesenchymal stem cells for corneal endothelial replacement and regeneration are evaluated.
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8
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Generation of Femtosecond Laser-Cut Decellularized Corneal Lenticule Using Hypotonic Trypsin-EDTA Solution for Corneal Tissue Engineering. J Ophthalmol 2018; 2018:2590536. [PMID: 29805794 PMCID: PMC5901861 DOI: 10.1155/2018/2590536] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 03/10/2018] [Indexed: 11/18/2022] Open
Abstract
Purpose To establish an optimized and standardized protocol for the development of optimal scaffold for bioengineering corneal substitutes, we used femtosecond laser to process human corneal tissue into stromal lenticules and studied to find the most efficient decellularization method among various reagents with different tonicities. Methods The decellularization efficacy of several agents (0.1%, 0.25%, and 0.5% of Triton X-100, SDS, and trypsin-EDTA (TE), resp.) with different tonicities was evaluated. Of all protocols, the decellularization methods, which efficiently removed nuclear materials examined as detected by immunofluorescent staining, were quantitatively tested for sample DNA and glycosaminoglycan (GAG) contents, recellularization efficacy, and biocompatibilities. Results 0.5% SDS in hypertonic and isotonic buffer, 0.25% TE in hypotonic buffer, and 0.5% TE in all tonicities completely decellularized the corneal lenticules. Of the protocols, decellularization with hypotonic 0.25 and 0.5% TE showed the lowest DNA contents, while the GAG content was the highest. Furthermore, the recellularization efficacy of the hypotonic TE method was better than that of the SDS-based method. Hypotonic TE-treated decellularized corneal lenticules (DCLs) were sufficiently transparent and biocompatible. Conclusion We generated an ideal protocol for DCLs using a novel method. Furthermore, it is possible to create a scaffold using a bioengineered corneal substitute.
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Costa D, Leiva M, Naranjo C, Ríos J, Peña MT. Cryopreservation (-20 °C) of canine corneoscleral tissue: histological, microbiological, and ultrastructural study. Vet Ophthalmol 2017; 21:556-564. [PMID: 29266715 DOI: 10.1111/vop.12544] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To evaluate microbiological, histological, and ultrastructural characteristics of short-term cryopreserved (STC) canine corneoscleral tissue (<1 year) and to compare it with long-term cryopreserved (LTC) tissue (>6 years). ANIMALS STUDIED Thirty-six healthy canine globes. PROCEDURE After a decontamination protocol, globes were enucleated and stored at -20 °C. Corneoscleral tissue was evaluated at different periods: <1 year (20 eyes) and >6 years (12 eyes). Four eyes were used as controls. Microbiologic study included direct (blood, McConkey and Sabouraud agars) and enrichment (brain-heart infusion broth) cultures. Cryopreservation artifacts were evaluated by hematoxylin-eosin. Corneoscleral collagen organization and number of normal and dead keratocytes were established by transmission electron microscopy (TEM). Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was also used for keratocyte characterization. RESULTS Corneal microbial growth was observed in 25% of the direct STC cultures, and in 47.4% and 16.7% of the enriched STC and LTC cultures, respectively. Scleral STC direct cultures were 30% positive, while enrichment cultures were positive in 66.7% and 16.7% of the STC and LTC, respectively (P = 0.011). Cryopreservation artifacts were higher in LTC tissues (P < 0.001). Apoptotic keratocytes were predominant by TEM and TUNEL, in both STC and LTC. Minimal structural differences were detected in collagen organization between STC and LTC. CONCLUSIONS Cryopreservation of canine corneoscleral tissue seems to reduce bacterial contamination over time. Apoptosis is the main way of death of cryopreserved canine keratocytes. Based on the lack of significant structural differences between STC and LTC samples, these cryopreserved tissues could potentially be used for tectonic support for at least 8 years without structural or microbiological impediment.
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Affiliation(s)
- Daniel Costa
- Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Marta Leiva
- Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.,Servei d'Oftalmologia de la Fundació Hospital Clínic Veterinari, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Carolina Naranjo
- Departamento de Medicina y Cirugía Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
| | - José Ríos
- Laboratory of Biostatistics & Epidemiology, Facultat de Medicina, IDIBAPS, Hospital Clínic, Universitat Autònoma de Barcelona, Bellaterra and Biostatistics and Data Management Platform, Barcelona, Spain
| | - Maria T Peña
- Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.,Servei d'Oftalmologia de la Fundació Hospital Clínic Veterinari, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
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10
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Wong KH, Kam KW, Chen LJ, Young AL. Corneal blindness and current major treatment concern-graft scarcity. Int J Ophthalmol 2017; 10:1154-1162. [PMID: 28730122 DOI: 10.18240/ijo.2017.07.21] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 09/26/2016] [Indexed: 11/23/2022] Open
Abstract
According to World Health Organization, the global prevalence of blindness in 2010 was 39 million people, among which 4% were due to corneal opacities. Often, the sole resort for visual restoration of patients with damaged corneas is corneal transplantation. However, despite rapid developments of surgical techniques, instrumentations and immunosuppressive agents, corneal blindness remains a prevalent global health issue. This is largely due to the scarcity of good quality corneal grafts. In this review, the causes of corneal blindness, its major treatment options, and the major contributory factors of corneal graft scarcity with potential solutions are discussed.
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Affiliation(s)
- Kah Hie Wong
- Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - Ka Wai Kam
- Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong, China
| | - Li Jia Chen
- Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong, China.,Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong, China
| | - Alvin L Young
- Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong, China.,Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong, China
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11
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Costa D, Leiva M, Naranjo C, Ríos J, Peña MT. Cryopreservation (-20 °C) of feline corneoscleral tissue: histologic, microbiologic, and ultrastructural study. Vet Ophthalmol 2016; 19 Suppl 1:97-104. [PMID: 27270861 DOI: 10.1111/vop.12393] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVE To evaluate microbiological, histologic, and ultrastructural characteristics of short-term cryopreserved (STC) feline corneoscleral tissue (<1 year) and to compare it with long-term cryopreserved (LTC) tissue (>7 years). ANIMALS STUDIED Twenty healthy feline globes were obtained from 2003 to 2013. PROCEDURE After a decontamination protocol, globes were enucleated and stored at -20 °C in broad-spectrum antibiotics. Corneoscleral tissue was evaluated at different storage periods: <1 year (10 eyes) and >7 years (8 eyes). Two eyes were used as controls. Microbiologic study included direct (blood, McConkey, and Sabouraud agars) and enrichment (brain-heart infusion broth) cultures. Cryopreservation artifacts were evaluated by hematoxylin-eosin. Corneoscleral collagen organization and number of normal and dead keratocytes were established by transmission electron microscopy. RESULTS Although microbiologic cultures were positive only in STC [direct (20.8%); enrichment (37.5%)], significant differences between periods were only found in enrichment cultures (P = 0.006). Cryopreservation artifacts were most commonly observed in LTC tissues (P < 0.001). Normal keratocytes were predominant in STC corneas (STC 58.3%, LTC 12.5%) and apoptotic ones in LTC (STC 41.7%, LTC 75%), whereas necrotic keratocytes were only seen in LTC (LTC 12.5%) (P = 0.046). No structural differences were detected in collagen organization between STC and LTC (Pcornea = 0.147; Psclera = 0.362). CONCLUSIONS Cryopreservation of feline corneoscleral tissue seems to reduce bacterial contamination over time. Apoptosis is the main cause of death of cryopreserved feline keratocytes. Based on the lack of significant structural differences between STC and LTC samples, these cryopreserved tissues could potentially be used for tectonic support for at least 10 years without structural or microbiological impediment.
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Affiliation(s)
- Daniel Costa
- Facultat de Veterinària, Servei d'Oftalmologia de la Fundació Hospital Clínic Veterinari, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Marta Leiva
- Facultat de Veterinària, Servei d'Oftalmologia de la Fundació Hospital Clínic Veterinari, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.,Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Carolina Naranjo
- Departamento de Medicina y Cirugía Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
| | - José Ríos
- Laboratory of Biostatistics & Epidemiology, Facultat de Medicina, Bellaterra and Biostatistics and Medical Statistics Core Facility, Hospital Clínic, IDIBAPS, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Maria Teresa Peña
- Facultat de Veterinària, Servei d'Oftalmologia de la Fundació Hospital Clínic Veterinari, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.,Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
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12
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Isolation of a recombinant antibody specific for a surface marker of the corneal endothelium by phage display. Sci Rep 2016; 6:21661. [PMID: 26902886 PMCID: PMC4763205 DOI: 10.1038/srep21661] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/13/2016] [Indexed: 12/13/2022] Open
Abstract
Cell surface antigens are important targets for monoclonal antibodies, but they are often difficult to work with due to their association with the cell membrane. Phage display is a versatile technique that can be applied to generate binders against difficult targets. Here we used antibody phage display to isolate a binder for a rare and specialized cell, the human corneal endothelial cell. The human corneal endothelium is a medically important cell layer; defects in this layer account for about half of all corneal transplants. Despite its importance, no specific antigens have been found to mark this cell type. By panning a phage library directly on human corneal endothelial cells, we isolated an antibody that bound to these cells and not the other types of corneal cells. Subsequently, we identified the antibody's putative target to be CD166 by immunoprecipitation and mass spectrometry. This approach can be used to isolate antibodies against other poorly-characterized cell types, such as stem cells or cancer cells, without any prior knowledge of their discriminating markers.
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13
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The effects of Rho-associated kinase inhibitor Y-27632 on primary human corneal endothelial cells propagated using a dual media approach. Sci Rep 2015; 5:9167. [PMID: 25823914 PMCID: PMC4387913 DOI: 10.1038/srep09167] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 02/23/2015] [Indexed: 12/13/2022] Open
Abstract
The global shortage of donor corneas has garnered extensive interest in the development of graft alternatives suitable for endothelial keratoplasty using cultivated primary human corneal endothelial cells (CECs). We have recently described a dual media approach for the propagation of human CECs. In this work, we characterize the effects of a Rho-kinase inhibitor Y-27632 on the cultivation of CECs propagated using the dual media culture system. Seventy donor corneas deemed unsuitable for transplantation were procured for this study. We assessed the use of Y-27632 for its effect at each stage of the cell culture process, specifically for cell attachment, cell proliferation, and during both regular passaging and cryopreservation. Lastly, comparison of donor-matched CEC-cultures expanded with or without Y-27632 was also performed. Our results showed that Y-27632 significantly improved the attachment and proliferation of primary CECs. A non-significant pro-survival effect was detected during regular cellular passage when CECs were pre-treated with Y-27632, an effect that became more evident during cryopreservation. Our study showed that the inclusion of Y-27632 was beneficial for the propagation of primary CECs expanded via the dual media approach, and was able to increase overall cell yield by between 1.96 to 3.36 fold.
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14
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Peh GSL, Chng Z, Ang HP, Cheng TYD, Adnan K, Seah XY, George BL, Toh KP, Tan DT, Yam GHF, Colman A, Mehta JS. Propagation of Human Corneal Endothelial Cells: A Novel Dual Media Approach. Cell Transplant 2015; 24:287-304. [DOI: 10.3727/096368913x675719] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Corneal endothelium-associated corneal blindness is the most common indication for corneal transplantation. Restorative corneal transplant surgery is the only option to reverse the blindness, but a global shortage of donor material remains an issue. There are immense clinical interests in the development of alternative treatment strategies to alleviate current reliance on donor materials. For such endeavors, ex vivo propagation of human corneal endothelial cells (hCECs) is required, but current methodology lacks consistency, with expanded hCECs losing cellular morphology to a mesenchymal-like transformation. In this study, we describe a novel dual media culture approach for the in vitro expansion of primary hCECs. Initial characterization included analysis of growth dynamics of hCECs grown in either proliferative (M4) or maintenance (M5) medium. Subsequent comparisons were performed on isolated hCECs cultured in M4 alone against cells expanded using the dual media approach. Further characterizations were performed using immunocytochemistry, quantitative real-time PCR, and gene expression microarray. At the third passage, results showed that hCECs propagated using the dual media approach were homogeneous in appearance, retained their unique polygonal cellular morphology, and expressed higher levels of corneal endothelium-associated markers in comparison to hCECs cultured in M4 alone, which were heterogeneous and fibroblastic in appearance. Finally, for hCECs cultured using the dual media approach, global gene expression and pathway analysis between confluent hCECs before and after 7-day exposure to M5 exhibited differential gene expression associated predominately with cell proliferation and wound healing. These findings showed that the propagation of primary hCECs using the novel dual media approach presented in this study is a consistent method to obtain bona fide hCECs. This, in turn, will elicit greater confidence in facilitating downstream development of alternative corneal endothelium replacement using tissue-engineered graft materials or cell injection therapy.
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Affiliation(s)
- Gary S. L. Peh
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Zhenzhi Chng
- A*STAR Institute of Medical Biology, Singapore, Singapore
| | - Heng-Pei Ang
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore
| | | | - Khadijah Adnan
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Xin-Yi Seah
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Benjamin L. George
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Kah-Peng Toh
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Donald T. Tan
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore
- Singapore National Eye Centre, Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Gary H. F. Yam
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Alan Colman
- A*STAR Institute of Medical Biology, Singapore, Singapore
| | - Jodhbir S. Mehta
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore
- Singapore National Eye Centre, Singapore, Singapore
- Duke Medical School of Medicine, National University of Singapore, Singapore, Singapore
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15
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Xiao X, Pan S, Liu X, Zhu X, Connon CJ, Wu J, Mi S. In vivo study of the biocompatibility of a novel compressed collagen hydrogel scaffold for artificial corneas. J Biomed Mater Res A 2013; 102:1782-7. [PMID: 23813783 DOI: 10.1002/jbm.a.34848] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 06/08/2013] [Accepted: 06/11/2013] [Indexed: 12/13/2022]
Abstract
The experiments were designed to evaluate the biocompatibility of a plastically compressed collagen scaffold (PCCS). The ultrastructure of the PCCS was observed via scanning electron microscopy. Twenty New Zealand white rabbits were randomly divided into experimental and control groups that received corneal pocket transplantation with PCCS and an amniotic membrane, respectively. And the contralateral eye of the implanted rabbit served as the normal group. On the 1st, 7th, 14th, 21st, 30th, 60th, 90th, and 120th postoperative day, the eyes were observed via a slit lamp. On the 120th postoperative day, the rabbit eyes were enucleated to examine the tissue compatibility of the implanted stroma. The PCCS was white and translucent. The scanning electron microscopy results showed that fibers within the PCCS were densely packed and evenly arranged. No edema, inflammation, or neovascularization was observed on ocular surface under a slit lamp and few lymphocytes were observed in the stroma of rabbit cornea after histological study. In conclusion, the PCCS has extremely high biocompatibility and is a promising corneal scaffold for an artificial cornea.
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Affiliation(s)
- Xianghua Xiao
- Shaanxi Institute of Ophthalmology, Xi'an, Shaanxi, 710002, People's Republic of China; Shaanxi Key Laboratory of Eye, Xi'an, Shaanxi, 710002, People's Republic of China; Xi'an First Hospital, Xi'an, Shaanxi, 710002, People's Republic of China
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16
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Peh GSL, Lee MX, Wu FY, Toh KP, Balehosur D, Mehta JS. Optimization of human corneal endothelial cells for culture: the removal of corneal stromal fibroblast contamination using magnetic cell separation. Int J Biomater 2012; 2012:601302. [PMID: 22287967 PMCID: PMC3263628 DOI: 10.1155/2012/601302] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 10/06/2011] [Accepted: 10/06/2011] [Indexed: 12/13/2022] Open
Abstract
The culture of human corneal endothelial cells (CECs) is critical for the development of suitable graft alternative on biodegradable material, specifically for endothelial keratoplasty, which can potentially alleviate the global shortage of transplant-grade donor corneas available. However, the propagation of slow proliferative CECs in vitro can be hindered by rapid growing stromal corneal fibroblasts (CSFs) that may be coisolated in some cases. The purpose of this study was to evaluate a strategy using magnetic cell separation (MACS) technique to deplete the contaminating CSFs from CEC cultures using antifibroblast magnetic microbeads. Separated "labeled" and "flow-through" cell fractions were collected separately, cultured, and morphologically assessed. Cells from the "flow-through" fraction displayed compact polygonal morphology and expressed Na(+)/K(+)ATPase indicative of corneal endothelial cells, whilst cells from the "labeled" fraction were mostly elongated and fibroblastic. A separation efficacy of 96.88% was observed. Hence, MACS technique can be useful in the depletion of contaminating CSFs from within a culture of CECs.
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Affiliation(s)
| | - Man-Xin Lee
- Singapore Eye Research Institute, Singapore 168751
| | - Fei-Yi Wu
- Singapore Eye Research Institute, Singapore 168751
| | - Kah-Peng Toh
- Singapore Eye Research Institute, Singapore 168751
| | | | - Jodhbir S. Mehta
- Singapore Eye Research Institute, Singapore 168751
- Singapore National Eye Centre, Singapore 168751
- Duke-NUS Graduate Medical School Singapore, Singapore 169857
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228
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17
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Human corneal endothelial cell expansion for corneal endothelium transplantation: an overview. Transplantation 2011; 91:811-9. [PMID: 21358368 DOI: 10.1097/tp.0b013e3182111f01] [Citation(s) in RCA: 174] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The monolayer of cells forming the human corneal endothelium is critical to the maintenance of corneal transparency and is not known to regenerate in vivo. Thus, dysfunction of these cells constitutes the most often cited reasons for the 150,000 or so corneal transplants performed yearly. Although current corneal transplantation is more than 90% successful at 1 year, longer term results are not as encouraging with approximately 70% success at 5 years. Nonimmunologic graft failure and allograft endothelial rejection are the main problems. Furthermore, the global shortage of donor corneas greatly restricts several corneal transplantations performed. With advances in understanding corneal endothelial cell biology, it is now possible to cultivate human corneal endothelial cells (HCECs) in vitro, thus providing new opportunities to develop novel tissue-engineered human corneal endothelium. This review will provide an overview of (a) the characteristics of human corneal endothelium; (b) past and present HCECs isolation and culture protocols; (c) various potential carriers for the generation of tissue-engineered corneal endothelium, together with some of the functional studies reported in various animal models; and (d) the current rapid advancements in surgical techniques for keratoplasty. A successful combination of tissue-engineered human corneal endothelium coupled with innovative and groundbreaking surgical procedures will bridge basic research involving cultured HCECs, bringing it from bench to bedside.
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18
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Nuzzo V, Savoldelli M, Legeais JM, Plamann K. Self-focusing and spherical aberrations in corneal tissue during photodisruption by femtosecond laser. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:038003. [PMID: 20615049 DOI: 10.1117/1.3455507] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The use of ultrashort pulse lasers is current in refractive surgery and has recently been extended to corneal grafting (keratoplasty). When performing keratoplasty, however, permanent degradation of the optical properties of the patient's cornea compromises the penetration depth of the laser and the quality of the incisions, therefore causing unwanted secondary effects. Additionally, corneal grafting needs considerably higher penetration depths than refractive surgery. Little data are available about the interaction processes of the femtosecond pulses in the volume of pathological corneas-i.e., in the presence of spherical aberrations and optical scattering. We investigate the influence of the focusing numerical aperture on the laser-tissue interaction. We point out that at low numerical apertures (NAs), tissue damage is produced below and above the focal region. We attribute this phenomenon to nonlinear self-focusing effects. On the other hand, at high NAs, spherical aberrations become significant when focusing at high depths for posterior surgeries, which also limit the cutting efficiency. As high NAs are advisable for reducing unwanted nonlinear effects and ensure accurate cutting, particular attention should be paid to aberration management when developing clinical femtosecond lasers.
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Affiliation(s)
- Valeria Nuzzo
- Laboratoire d'Optique Appliquee, ENSTA-Ecole Polytechnique-CNRS UMR 7639, Chemin de la Huniere, 91761 Palaiseau cedex, France.
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