The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
G Thuret - One of the best experts on this subject based on the ideXlab platform.
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innovative corneal active storage machine for long term Eye Banking
American Journal of Transplantation, 2019Co-Authors: Thibaud Garcin, Z He, S Acquart, Fabrice Cognasse, Annesophie Gauthier, Emmanuel Crouzet, Pascal Herbepin, Chantal Perrache, Fabien Forest, G ThuretAbstract:: Optimal ex vivo corneal storage in Eye banks is crucial to increase both the number of corneas suitable for graft and their intrinsic quality, mainly the number of viable endothelial cells, which dictates graft survival in recipients. With both passive storage methods used worldwide (short-term cold storage in the United States, long-term organ culture in Europe), significant endothelial cell loss is inevitable. Here we show that, with an active storage machine, also called a bioreactor, which restores 2 fundamental physiological parameters, intraocular pressure and medium renewal, endothelial cell survival is improved by 23% compared with organ culture after 4 weeks' storage. Also observed in the bioreactor is a 4-fold higher expression of Na+ /K+ ATPase, which supports one of the major endothelial cell pumping functions. In addition, corneas remain thin and transparent, so they are suitable for surgery at any time. This new active Eye Banking method may help to reduce the severe global scarcity of donor corneas.
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global survey of corneal transplantation and Eye Banking
JAMA Ophthalmology, 2016Co-Authors: Philippe Gain, Mansour Aldossary, Z He, G Thuret, R Jullienne, S Acquart, Fabrice CognasseAbstract:Importance Corneal transplantation restores visual function when visual impairment caused by a corneal disease becomes too severe. It is considered the world’s most frequent type of transplantation, but, to our knowledge, there are no exhaustive data allowing measurement of supply and demand, although such data are essential in defining local, national, and global strategies to fight corneal blindness. Objective To describe the worldwide situation of corneal transplantation supply and demand. Design, Setting, and Participants Data were collected between August 2012 and August 2013 from a systematic review of published literature in parallel with national and international reports on corneal transplantation and Eye Banking. In a second step, Eye bank staff and/or corneal surgeons were interviewed on their local activities. Interviews were performed during international ophthalmology or Eye-Banking congresses or by telephone or email. Countries’ national supply/demand status was classified using a 7-grade system. Data were collected from 148 countries. Main Outcomes and Measures Corneal transplantation and corneal procurements per capita in each country. Results In 2012, we identified 184 576 corneal transplants performed in 116 countries. These were procured from 283 530 corneas and stored in 742 Eye banks. The top indications were Fuchs dystrophy (39% of all corneal transplants performed), a primary corneal edema mostly affecting elderly individuals; keratoconus (27%), a corneal disease that slowly deforms the cornea in young people; and sequellae of infectious keratitis (20%). The United States, with 199.10 −6 corneal transplants per capita, had the highest transplantation rate, followed by Lebanon (122.10 −6 ) and Canada (117.10 −6 ), while the median of the 116 transplanting countries was 19.10 −6 . Corneas were procured in only 82 countries. Only the United States and Sri Lanka exported large numbers of donor corneas. About 53% of the world’s population had no access to corneal transplantation. Conclusions and Relevance Our survey globally quantified the considerable shortage of corneal graft tissue, with only 1 cornea available for 70 needed. Efforts to encourage cornea donation must continue in all countries, but it is also essential to develop alternative and/or complementary solutions, such as corneal bioengineering.
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non invasive measurement of transparency arcus senilis and scleral rim diameter of corneas during Eye Banking
Cell and Tissue Banking, 2014Co-Authors: S Acquart, Z He, N Campolmi, R Jullienne, G Pataia, Olivier Garraud, Frederic Nguyen, Michel Peoch, Thierry Lepine, G ThuretAbstract:We developed a non-invasive device to quantify transparency (T), clear corneal diameter (CCD) excluding arcus senilis, and scleral rim diameter (SRD) of stored corneas. The T value (expressed in % on a relative scale), based on the modulation transfer function principle, referred to the ratio of local contrasts of a special LED backlit chart measured with and without cornea. CCD and SRD (in mm) were automatically calculated by morphologic operations. Firstly, we assessed measurement reproducibility. We then determined the agreement of T and CCD values with 3-level scores given independently by three experts on 179 scientific corneas. Thirdly, an Eye bank was equipped with the device, and 358 consecutive organ-cultured (OC) corneas were tested for donor- and storage- related factors possibly influencing T and CCD. Reproducibility of T, CCD and SRD measurements was high, with intraclass correlation coefficients of 0.982, 0.886, and 0.999 respectively. Capacity to discriminate the three levels of transparency and arcus senilis was good, with T of 20.0 (10.0–33.6), 38.3 (24.3–75.4) and 57.9 (33.9–90.0) % respectively for T deemed poor, average, and good (P < 0.001), and CCD of 9.8 (7.3–10.6), 10.5 (8.2–11.5), and 11.1 (9.9–12.0) mm respectively for arcus senilis deemed prominent, moderate or absent (P < 0.001). T was correlated with neither donor age nor endothelial cell density nor storage time, but slightly worsened during OC for corneas assessed twice. In conclusion, the device, which can be easily integrated in the facilities of an Eye bank, provides reliable objective measurement of T, CCD, and SRD. This could be a useful tool for standardizing quality assessment of stored corneas and consequently optimizing their selection for penetrating, endothelial or anterior lamellar keratoplasty.
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worldwide Eye Banking web project international survey of demand and supply
Acta Ophthalmologica, 2012Co-Authors: R Julienne, Mansour Aldossary, C Nefzaoui, Z He, N Campolmi, G Thuret, P GainAbstract:Purpose The whole Eye Banking (EB) process, from corneal retrieval to surgery, is improving. Paradoxically, corneal blindness worldwide is still increasing. Supply seems lagging far behind global demand but only partial data of the worldwide situation is available. We therefore launched an international survey on the balance of demand and supply, called the “Worldwide Eye Banking” (WEB)-project. Our goal is to identify suitable solutions in countries willing to improve their corneal supply Methods Descriptive epidemiological worldwide transversal study. A questionnaire was designed and e-mailed to EB staff and ophthalmologists involved in corneal grafts using mailing lists from local and international ophthalmological societies or by face to face interview during international ophthalmology, Eye research or EB congresses Results Significant disparities were highlighted. Developed countries tended to satisfy corneal demand. EBs in the United-States use short term storage and are exporters, while Europeans use long-term organoculture and nearly satisfy local demand. Keratoplasty indications have 2 profiles: infections, mainly trachoma, for developing countries and keratoconus, endothelial dystrophy or iatrogenic edema in developed countries Conclusion This demand/supply disparity, at this stage of the study (ongoing), is severe in most developing countries. Decreasing demand requires: 1) Trachoma fight in endemic zones, 2) Iatrogenic edema prevention. Increasing supply requires: 1) Corneal donation politic dynamism, 2) Local Eye Banking implantation in each country, 3) Optimizing storage technique for better efficiency (retrieved/delivered graft ratio), 4) Bioengineering of endothelial graft
Kirk R Wilhelmus - One of the best experts on this subject based on the ideXlab platform.
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Quality assessment and microbiologic screening of donor corneas.
Cornea, 2007Co-Authors: Sohela S Hassan, Kirk R WilhelmusAbstract:PURPOSE: To identify possible predictors of donor corneal contamination. METHODS: Relationships between Eye-Banking characteristics of donor corneas and surgical corneoscleral rim culture results were examined in a retrospective case-control study by using logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Of 263 donor corneal rims, microbial recovery occurred from 23 (9%), including 6 yielding Clostridium perfringens. After adjusting for outdoor temperature and death-to-preservation duration, a positive rim culture occurred more often among tissues having an acceptable but less favorable biomicroscopic rating (OR, 4.22; 95% CI, 1.27-13.98). CONCLUSIONS: This exploratory study suggests that slit-lamp assessment of corneal appearance may correlate with subsequent microbiologic results. Ensuring optimal selection and preservation of the donor cornea may contribute to the safety of Eye Banking.
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ecologic effects on Eye Banking
American Journal of Ophthalmology, 2006Co-Authors: Sohela S Hassan, Kirk R WilhelmusAbstract:Purpose To examine the climatic conditions at corneal donation for microbial categories of postkeratoplasty endophthalmitis that have been reported to a national surveillance registry. Design Retrospective case-control study. Methods Local weather information on the date of donor corneal procurement was tabulated for reported cases of endophthalmitis after penetrating keratoplasty and then compared between candidal endophthalmitis and postsurgical endophthalmitis that yielded bacteria or no microorganisms or that were not cultured. Results Compared with other postkeratoplasty endophthalmitis, candidal endophthalmitis after corneal transplantation occurred significantly ( P Conclusion Higher exterior temperatures at donation may be associated with an increased relative risk of candidal transmission by keratoplasty, but a chain of causation that links the donor's environment to the recipient's infection remains to be elucidated.
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Eye Banking risk factors for fungal endophthalmitis compared with bacterial endophthalmitis after corneal transplantation
American Journal of Ophthalmology, 2005Co-Authors: Sohela S Hassan, Kirk R WilhelmusAbstract:Purpose To track the relative frequency and explore possible risk factors of fungal compared with bacterial endophthalmitis after corneal transplantation. Design Case-comparison study nested in a surveillance registry. Methods We examined, among recipients who underwent surgery from January 1991 through December 2003, demographic and Eye-Banking characteristics of postkeratoplasty endophthalmitis cases that were reported to the Eye Bank Association of America by US Eye banks. Potential predictors of fungal compared with bacterial endophthalmitis were examined using multiple logistic regression. Results Of 234 reported cases of postkeratoplasty endophthalmitis reported by US Eye bank, 46 cases (19.7%) were fungal, and 130 cases (55.6%) were bacterial. Concordant cultures of the residual donor corneoscleral rim or preservation medium occurred significantly more often with fungal than bacterial endophthalmitis ( P = .009). After the introduction of Optisol-GS, the odds of bacterial relative to fungal endophthalmitis decreased by 77% (95% confidence interval, 44% - 91%). After adjustment for the preservation method and other Eye-Banking variables, the odds of fungal endophthalmitis was 3.4 (95% confidence interval, 1.6 - 7.4) times that of bacterial endophthalmitis, when donor corneal preservation was 4 days or longer. Conclusions The frequency of postkeratoplasty bacterial endophthalmitis compared with fungal endophthalmitis fell after widespread use of a corneal preservation medium supplemented with gentamicin and streptomycin. Further improvements in corneal preservation procedures are needed.
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Primary Corneal Graft Failure: A National Reporting System
Archives of Ophthalmology, 1995Co-Authors: Kirk R Wilhelmus, Joel Sugar, R. D. Stulting, Myrna M KhanAbstract:Objectives: To describe a national Eye Banking registry and to assess the effects of donor age, cause of donor death, time from death to procurement, storage time, and distance between the points of recovery and transplantation on the reported occurrence of primary corneal graft failure. Design: We performed a retrospective case-control study to estimate the odds ratios of five donor factors for cases of primary graft failure voluntarily reported to a national registry using controls from selected Eye banks. We also performed a nested case-control cohort study to compare cases of primary graft failure that occurred in both corneas from the same donor with those of nonmated corneas in which primary graft failure was reported to assess odds ratios for the same donor factors. Patients: One hundred forty-seven patients developed primary graft failure in penetrating keratoplasty transplantations performed between January 1, 1991, and December 31, 1993. These cases were reported to the Adverse Reaction Registry of the Eye Bank Association of America, Washington, DC. Controls included 7240 donor corneas distributed by nine Eye banks during 1992. Results: Of the 147 donor corneas that developed primary graft failure, 17 (12%) were obtained from donors who were aged 70 years and older, 39 (27%) came from donors who died of trauma, 13 (9%) had a cadaver time longer than 12 hours, 10 (7%) had a storage time longer than 7 days, and 38 (26%) were distributed outside the Eye bank's region. Compared with controls, these donor corneas were more likely to have a storage time longer than 7 days (odds ratio, 2.4; 95% confidence limits, 1.2 and 4.6) and to come from donors aged 70 years and older (odds ratio, 2.4; 95% confidence limits, 1.4 and 4.0). The 22 corneas (15%) in which primary graft failure occurred in both recipients from the same donor were 8.5 times (95% confidence limits, 1.1 and 51.5) more likely to be preserved beyond 1 week than were nonmated corneas with primary failure but were not from significantly older donors. Logistic regression analysis showed that the association between prolonged storage time and primary graft failure in mated corneas remained significant even when the analysis was controlled for other donor factors. Conclusions: No clearly defined donor or Eye Banking factor accounted for most cases of primary graft failure, although prolonged corneal storage and advanced donor age may increase its risk. Ophthalmologists are urged to report to their Eye bank all cases of primary graft failure and other adverse events that might be attributable to donor Eye tissue.
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the impact of state legislation on Eye Banking
Archives of Ophthalmology, 1994Co-Authors: Emile J Farge, Lance M Silverman, Myrna M Khan, Kirk R WilhelmusAbstract:Corneal transplantation, the most common transplantation procedure done in the United States, requires access to a sufficient number of donor Eyes. We examined how laws governing tissue donation affect availability of corneal tissue by reviewing records of the Lions Eye Bank of Texas, Houston, from 1961 through 1990 (43 696 Eyes from 21 898 donors). Relevant Texas statutes included the Uniform Anatomical Gift Act of 1970, the Justice of the Peace/Medical Examiner Law of 1977, and the Routine Inquiry Law of 1988. Before 1970, the mean (±SD) number of donated corneas was 72±38 per year; enactment of each statute above was associated with increased mean annual donations of 215±87,1329±562, and 1958±33 corneas, respectively. The Justice of the Peace/Medical Examiner Law yielded significantly younger donors (who died of trauma), and the Routine Inquiry Law increased the number of hospitalized donors. Data from this Eye bank were compared with current state laws nationwide. Effective legislation is a means to meet national ophthalmic surgical needs.
Z He - One of the best experts on this subject based on the ideXlab platform.
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innovative corneal active storage machine for long term Eye Banking
American Journal of Transplantation, 2019Co-Authors: Thibaud Garcin, Z He, S Acquart, Fabrice Cognasse, Annesophie Gauthier, Emmanuel Crouzet, Pascal Herbepin, Chantal Perrache, Fabien Forest, G ThuretAbstract:: Optimal ex vivo corneal storage in Eye banks is crucial to increase both the number of corneas suitable for graft and their intrinsic quality, mainly the number of viable endothelial cells, which dictates graft survival in recipients. With both passive storage methods used worldwide (short-term cold storage in the United States, long-term organ culture in Europe), significant endothelial cell loss is inevitable. Here we show that, with an active storage machine, also called a bioreactor, which restores 2 fundamental physiological parameters, intraocular pressure and medium renewal, endothelial cell survival is improved by 23% compared with organ culture after 4 weeks' storage. Also observed in the bioreactor is a 4-fold higher expression of Na+ /K+ ATPase, which supports one of the major endothelial cell pumping functions. In addition, corneas remain thin and transparent, so they are suitable for surgery at any time. This new active Eye Banking method may help to reduce the severe global scarcity of donor corneas.
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global survey of corneal transplantation and Eye Banking
JAMA Ophthalmology, 2016Co-Authors: Philippe Gain, Mansour Aldossary, Z He, G Thuret, R Jullienne, S Acquart, Fabrice CognasseAbstract:Importance Corneal transplantation restores visual function when visual impairment caused by a corneal disease becomes too severe. It is considered the world’s most frequent type of transplantation, but, to our knowledge, there are no exhaustive data allowing measurement of supply and demand, although such data are essential in defining local, national, and global strategies to fight corneal blindness. Objective To describe the worldwide situation of corneal transplantation supply and demand. Design, Setting, and Participants Data were collected between August 2012 and August 2013 from a systematic review of published literature in parallel with national and international reports on corneal transplantation and Eye Banking. In a second step, Eye bank staff and/or corneal surgeons were interviewed on their local activities. Interviews were performed during international ophthalmology or Eye-Banking congresses or by telephone or email. Countries’ national supply/demand status was classified using a 7-grade system. Data were collected from 148 countries. Main Outcomes and Measures Corneal transplantation and corneal procurements per capita in each country. Results In 2012, we identified 184 576 corneal transplants performed in 116 countries. These were procured from 283 530 corneas and stored in 742 Eye banks. The top indications were Fuchs dystrophy (39% of all corneal transplants performed), a primary corneal edema mostly affecting elderly individuals; keratoconus (27%), a corneal disease that slowly deforms the cornea in young people; and sequellae of infectious keratitis (20%). The United States, with 199.10 −6 corneal transplants per capita, had the highest transplantation rate, followed by Lebanon (122.10 −6 ) and Canada (117.10 −6 ), while the median of the 116 transplanting countries was 19.10 −6 . Corneas were procured in only 82 countries. Only the United States and Sri Lanka exported large numbers of donor corneas. About 53% of the world’s population had no access to corneal transplantation. Conclusions and Relevance Our survey globally quantified the considerable shortage of corneal graft tissue, with only 1 cornea available for 70 needed. Efforts to encourage cornea donation must continue in all countries, but it is also essential to develop alternative and/or complementary solutions, such as corneal bioengineering.
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non invasive measurement of transparency arcus senilis and scleral rim diameter of corneas during Eye Banking
Cell and Tissue Banking, 2014Co-Authors: S Acquart, Z He, N Campolmi, R Jullienne, G Pataia, Olivier Garraud, Frederic Nguyen, Michel Peoch, Thierry Lepine, G ThuretAbstract:We developed a non-invasive device to quantify transparency (T), clear corneal diameter (CCD) excluding arcus senilis, and scleral rim diameter (SRD) of stored corneas. The T value (expressed in % on a relative scale), based on the modulation transfer function principle, referred to the ratio of local contrasts of a special LED backlit chart measured with and without cornea. CCD and SRD (in mm) were automatically calculated by morphologic operations. Firstly, we assessed measurement reproducibility. We then determined the agreement of T and CCD values with 3-level scores given independently by three experts on 179 scientific corneas. Thirdly, an Eye bank was equipped with the device, and 358 consecutive organ-cultured (OC) corneas were tested for donor- and storage- related factors possibly influencing T and CCD. Reproducibility of T, CCD and SRD measurements was high, with intraclass correlation coefficients of 0.982, 0.886, and 0.999 respectively. Capacity to discriminate the three levels of transparency and arcus senilis was good, with T of 20.0 (10.0–33.6), 38.3 (24.3–75.4) and 57.9 (33.9–90.0) % respectively for T deemed poor, average, and good (P < 0.001), and CCD of 9.8 (7.3–10.6), 10.5 (8.2–11.5), and 11.1 (9.9–12.0) mm respectively for arcus senilis deemed prominent, moderate or absent (P < 0.001). T was correlated with neither donor age nor endothelial cell density nor storage time, but slightly worsened during OC for corneas assessed twice. In conclusion, the device, which can be easily integrated in the facilities of an Eye bank, provides reliable objective measurement of T, CCD, and SRD. This could be a useful tool for standardizing quality assessment of stored corneas and consequently optimizing their selection for penetrating, endothelial or anterior lamellar keratoplasty.
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worldwide Eye Banking web project international survey of demand and supply
Acta Ophthalmologica, 2012Co-Authors: R Julienne, Mansour Aldossary, C Nefzaoui, Z He, N Campolmi, G Thuret, P GainAbstract:Purpose The whole Eye Banking (EB) process, from corneal retrieval to surgery, is improving. Paradoxically, corneal blindness worldwide is still increasing. Supply seems lagging far behind global demand but only partial data of the worldwide situation is available. We therefore launched an international survey on the balance of demand and supply, called the “Worldwide Eye Banking” (WEB)-project. Our goal is to identify suitable solutions in countries willing to improve their corneal supply Methods Descriptive epidemiological worldwide transversal study. A questionnaire was designed and e-mailed to EB staff and ophthalmologists involved in corneal grafts using mailing lists from local and international ophthalmological societies or by face to face interview during international ophthalmology, Eye research or EB congresses Results Significant disparities were highlighted. Developed countries tended to satisfy corneal demand. EBs in the United-States use short term storage and are exporters, while Europeans use long-term organoculture and nearly satisfy local demand. Keratoplasty indications have 2 profiles: infections, mainly trachoma, for developing countries and keratoconus, endothelial dystrophy or iatrogenic edema in developed countries Conclusion This demand/supply disparity, at this stage of the study (ongoing), is severe in most developing countries. Decreasing demand requires: 1) Trachoma fight in endemic zones, 2) Iatrogenic edema prevention. Increasing supply requires: 1) Corneal donation politic dynamism, 2) Local Eye Banking implantation in each country, 3) Optimizing storage technique for better efficiency (retrieved/delivered graft ratio), 4) Bioengineering of endothelial graft
Fabrice Cognasse - One of the best experts on this subject based on the ideXlab platform.
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Three-month Storage of Human Corneas in an Active Storage Machine.
Transplantation, 2019Co-Authors: Thibaud Garcin, Fabrice Cognasse, Annesophie Gauthier, Emmanuel Crouzet, Pascal Herbepin, Chantal Perrache, Fabien Forest, Zhiguo He, Sophie Acquart, Philippe GainAbstract:BACKGROUND: Corneal storage over the very long term, without degradation, would make it possible to optimize a very limited resource worldwide. We previously demonstrated the superiority, over conventional 4-week passive organ culture (OC), of an active storage machine (ASM) that restores intraocular pressure and medium renewal. Here, we investigate Eye Banking for up to 3 months. METHODS: In a randomized preclinical trial with 24 paired corneas, 1 was stored in OC and the other in ASM, using the same medium. Assessments were done on the second day and at 3 months: endothelial cell density (ECD in cells/mm), corneal transparency and thickness. At D86, OC corneas were deswelled in a common hyperosmotic medium; but not the ASM corneas, which had remained thin. In addition, at D88, viable ECD was measured using a live/dead assay, and endothelial expression of Na/KATPase, Cox-IV, ZO-1, N-CAM and CD166 was observed. RESULTS: The ASM extended storage to 3 months with unprecedented EC quality: no OC corneas remained suitable for transplantation, but one-third of ASM corneas were compliant (ECD>2000/mm). Given that corneas with ECD>1600/mm were also usable for emergency, 58% of ASM corneas were usable versus 33% in OC. EC survival was 53% higher in ASM (p
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innovative corneal active storage machine for long term Eye Banking
American Journal of Transplantation, 2019Co-Authors: Thibaud Garcin, Z He, S Acquart, Fabrice Cognasse, Annesophie Gauthier, Emmanuel Crouzet, Pascal Herbepin, Chantal Perrache, Fabien Forest, G ThuretAbstract:: Optimal ex vivo corneal storage in Eye banks is crucial to increase both the number of corneas suitable for graft and their intrinsic quality, mainly the number of viable endothelial cells, which dictates graft survival in recipients. With both passive storage methods used worldwide (short-term cold storage in the United States, long-term organ culture in Europe), significant endothelial cell loss is inevitable. Here we show that, with an active storage machine, also called a bioreactor, which restores 2 fundamental physiological parameters, intraocular pressure and medium renewal, endothelial cell survival is improved by 23% compared with organ culture after 4 weeks' storage. Also observed in the bioreactor is a 4-fold higher expression of Na+ /K+ ATPase, which supports one of the major endothelial cell pumping functions. In addition, corneas remain thin and transparent, so they are suitable for surgery at any time. This new active Eye Banking method may help to reduce the severe global scarcity of donor corneas.
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Innovative corneal active storage machine for long‐term Eye Banking
American Journal of Transplantation, 2019Co-Authors: Thibaud Garcin, Fabrice Cognasse, Annesophie Gauthier, Emmanuel Crouzet, Pascal Herbepin, Chantal Perrache, Fabien Forest, Zhiguo He, Sophie Acquart, Gilles ThuretAbstract:Optimal ex vivo corneal storage in Eye banks is crucial to increase both the number of corneas suitable for graft and their intrinsic quality, mainly the number of viable endothelial cells, which dictates graft survival in recipients. With both passive storage methods used worldwide (short-term cold storage in the United States, long-term organ culture in Europe), significant endothelial cell loss is inevitable. Here we show that, with an active storage machine, also called a bioreactor, which restores 2 fundamental physiological parameters, intraocular pressure and medium renewal, endothelial cell survival is improved by 23% compared with organ culture after 4 weeks' storage. Also observed in the bioreactor is a 4-fold higher expression of Na+ /K+ ATPase, which supports one of the major endothelial cell pumping functions. In addition, corneas remain thin and transparent, so they are suitable for surgery at any time. This new active Eye Banking method may help to reduce the severe global scarcity of donor corneas.
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global survey of corneal transplantation and Eye Banking
JAMA Ophthalmology, 2016Co-Authors: Philippe Gain, Mansour Aldossary, Z He, G Thuret, R Jullienne, S Acquart, Fabrice CognasseAbstract:Importance Corneal transplantation restores visual function when visual impairment caused by a corneal disease becomes too severe. It is considered the world’s most frequent type of transplantation, but, to our knowledge, there are no exhaustive data allowing measurement of supply and demand, although such data are essential in defining local, national, and global strategies to fight corneal blindness. Objective To describe the worldwide situation of corneal transplantation supply and demand. Design, Setting, and Participants Data were collected between August 2012 and August 2013 from a systematic review of published literature in parallel with national and international reports on corneal transplantation and Eye Banking. In a second step, Eye bank staff and/or corneal surgeons were interviewed on their local activities. Interviews were performed during international ophthalmology or Eye-Banking congresses or by telephone or email. Countries’ national supply/demand status was classified using a 7-grade system. Data were collected from 148 countries. Main Outcomes and Measures Corneal transplantation and corneal procurements per capita in each country. Results In 2012, we identified 184 576 corneal transplants performed in 116 countries. These were procured from 283 530 corneas and stored in 742 Eye banks. The top indications were Fuchs dystrophy (39% of all corneal transplants performed), a primary corneal edema mostly affecting elderly individuals; keratoconus (27%), a corneal disease that slowly deforms the cornea in young people; and sequellae of infectious keratitis (20%). The United States, with 199.10 −6 corneal transplants per capita, had the highest transplantation rate, followed by Lebanon (122.10 −6 ) and Canada (117.10 −6 ), while the median of the 116 transplanting countries was 19.10 −6 . Corneas were procured in only 82 countries. Only the United States and Sri Lanka exported large numbers of donor corneas. About 53% of the world’s population had no access to corneal transplantation. Conclusions and Relevance Our survey globally quantified the considerable shortage of corneal graft tissue, with only 1 cornea available for 70 needed. Efforts to encourage cornea donation must continue in all countries, but it is also essential to develop alternative and/or complementary solutions, such as corneal bioengineering.
Katrin Engelmann - One of the best experts on this subject based on the ideXlab platform.
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evaluation of potential organ culture media for Eye Banking using a human corneal endothelial cell growth assay
Graefes Archive for Clinical and Experimental Ophthalmology, 2001Co-Authors: Torben Mollerpedersen, Ulrike Hartmann, Niels Ehlers, Katrin EngelmannAbstract:Background: To evaluate the ability of different commercially available cell culture media to induce proliferation and morphological changes in primary cultures of human corneal endothelial cells (HCEC). This screening model was used in an attempt to establish a rational basis for the development of well-defined, serum-free preservation media for long-term organ culture of human donor corneas. Methods: A total of 11 different culture media enriched with 0%, 2%, 5%, and 10% fetal calf serum (FCS) were compared. The test media were divided into three groups: Group 1: Media based on minimal essential medium (MEM), currently used for long-term corneal organ culture in European Eye banks; Group 2: F99-based media, enriched for growth of corneal endothelial cells at serum-reduced conditions; and Group 3: Media designed for growth of special cell types or for short-term corneal organ culture. The growth-promoting capacity of each test medium was quantified using an HCEC proliferation assay, whereas changes in cell morphology were evaluated by phase-contrast microscopy. Results: The morphological characteristics of HCEC were best maintained in the group of F99-based media, which also induced the highest level of cell proliferation under serum-reduced conditions. Specifically, the medium F99-Sr (F99 enriched with ascorbic acid, insulin, bFGF, transferrin, selenium, and lipids) induced a two- to three-fold higher HCEC density at both 0% and 2% FCS when compared to all other test media, and it also maintained the most endothelial cell-like morphology. Also, at higher serum concentrations (5% and 10% FCS), the cell growth was most prominent in F99-Sr, as well as in the medium SFM that originally was designed for serum-free growth of vascular endothelial cells. Conclusion: This study suggests that the media F99-Sr and SFM should be further tested and refined as potential new storage solutions for long-term corneal organ culture at physiological temperatures.
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evaluation of potential organ culture media for Eye Banking using human donor corneas
British Journal of Ophthalmology, 2001Co-Authors: Torben Mollerpedersen, Ulrike Hartmann, Holger Jon Moller, Niels Ehlers, Katrin EngelmannAbstract:AIM To evaluate the ability of different commercially available cell culture solutions to preserve human donor corneas during 3 weeks of “closed system” organ culture at physiological temperature. This screening was performed in an attempt to establish a rational basis for the development of a serum-free organ culture medium for Eye Banking. METHODS 72 normal human donor corneas were organ cultured for 21 days at 31°C in eight different test media (nine corneas in each group). The basic culture solutions included: minimal essential medium (MEM), MEM with stabilised l-glutamine, M199, DIF-1000, SFM, F99, and F99 with ascorbic acid, insulin, bFGF, transferrin, selenium, and lipids (termed F99-Sr). All media were supplemented with 2% fetal calf serum (FCS), except for MEM, which was also studied at 8% FCS. The evaluation parameters included: (1) the endothelial cell loss as evaluated using trypan blue staining; (2) the ability of keratocytes and endothelial cells to incorporate tritiated uridine into RNA as evaluated using autoradiography and digital image analysis; (3) the leakage of immunogenic keratan sulphate as assessed using ELISA; and (4) changes in storage medium pH, glucose, and lactate content. RESULTS SFM induced the lowest endothelial cell loss of 14% (SD 2%) and the highest RNA synthesis rates of all test solutions supplemented with 2% FCS. Corneas stored in SFM also showed the least leakage of keratan sulphate and the highest glucose consumption and lactate production. In five media (MEM with 2% FCS, MEM with stabilised l-glutamine, M199, F99, and F99-Sr), comparable and intermediate potentials for organ culture were observed with endothelial cell loss of 16–19%. By contrast, 29% (4%) of the endothelium was lost after storage in DIF-1000. Interestingly, the use of 8% FCS (in MEM) had a marked protective effect on the endothelium, which showed the highest RNA synthetic activity combined with a cell loss of only 11% (4%), compared with 19% (6%) at 2% FCS (p CONCLUSION Among the present test solutions, SFM appears to be the most prominent candidate for a new corneal organ culture medium and should be further tested and possibly refined to effectively substitute serum addition.
