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Background: Aniridia is a rare panocular, bilateral, and congenital disease characterized by complete or partial iris hypoplasia and foveal hypoplasia, leading to decreased visual acuity and nystagmus. AAK, also referred to as aniridic keratopathy, manifests as corneal surface damage, epithelial thinning or loss, inflammation with immune cell infiltration, vascularization, and chronic progressive opacification. Methods: Twenty-one eyes in eighteen patients with aniridia underwent the triple procedure for visual rehabilitation. Subjects with stromal scarring with mild limbal deficiency were qualified for surgery. The majority of them developed stage II (15), and a few of them had third-degree (6) aniridic keratopathy. Results: The mean patient age was 38.4 ± 8.8. Visual acuity after one year of observation ranged from 0.4 in two eyes to 0.2 in nine eyes to below 0.1 in ten eyes. In the second year, VA remained at the same level in 13 patients (72.2%). In the third year, four patients (22.2%) experienced recurrence of AAK. Conclusions: A majority of the ARK cases (72.2%) had a graft providing useful vision for the patient 2 years after corneal transplantation, but the visual gain was modest at best. Longer follow-up time is required to evaluate functional graft outcomes. [ABSTRACT FROM AUTHOR]

Background/aimsCorneal endothelial cell loss contributes to transplant failure. Autologous plasma products (APP) activate salvaging pathways that can prevent oxidative stress perioperatively. This study aimed to evaluate the safety of intraoperative incubation of full-thickness corneal grafts in platelet-rich plasma (aPRP) and plasma rich in growth factors (PRGF-Endoret) in mitigating postoperative corneal endothelial cell loss (ECL).MethodsPilot study including patients undergoing penetrating keratoplasty (PK) for various indications between June 2021 and December 2022. Patients were randomly assigned to receive either aPRP or PRGF-Endoret incubation, while those who declined intervention served as the control group. Demographic and clinical data were collected, including preoperative and postoperative endothelial cell count, intraocular pressure, pachymetry, and adverse reactions.ResultsThirty individuals who underwent PK completed follow-up: eight from the aPRP group, 10 from the PRGF-Endoret group, and 12 from the control group. No adverse events related to APP treatment were recorded. In the first and third postoperative months, the APP group had significantly lower ECL percentages (37% vs. 25%, p = 0.02, and 44% vs. 33%, p = 0.02, respectively); this trend was maintained in the sixth month. When stratified, the PRGF-Endoret group showed significant differences in ECL reduction compared to controls at both time points (p = 0.03 and p = 0.05, respectively). The aPRP group showed a similar statistically significant outcome exclusively on the third postoperative month (p = 0.04). APP tended to reduce corneal edema faster than controls. Hexagonality was significantly better in the APP groups in the first and third months, particularly in the PRGF-Endoret group (p

The inner structures of the eye are protected by the cornea, which is a transparent membrane exposed to the external environment and subjected to the risk of lesions and diseases, sometimes resulting in impaired vision and blindness. Several eye pathologies can be treated with a keratoplasty, a surgical procedure aimed at replacing the cornea with tissues from human donors. Even though the success rate is high (up to 90% for the first graft in low-risk patients at 5-year follow-up), this approach is limited by the insufficient number of donors and several clinically relevant drawbacks. Alternatively, keratoprosthesis can be applied in an attempt to restore minimal functions of the cornea: For this reason, it is used only for high-risk patients. Recently, many biomaterials of both natural and synthetic origin have been developed as corneal substitutes to restore and replace diseased or injured corneas in low-risk patients. After illustrating the traditional clinical approaches, the present paper aims to review the most innovative solutions that have been recently proposed to regenerate the cornea, avoiding the use of donor tissues. Finally, innovative approaches to biological tissue 3D printing and xenotransplantation will be mentioned. [ABSTRACT FROM AUTHOR]

Copyright of Türkiye Klinikleri Journal of Ophthalmology is the property of Turkiye Klinikleri and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background : Descemet membrane endothelial keratoplasty (DMEK) is increasingly favored in the treatment of endothelial dysfunction due to its benefits, which include swift visual rehabilitation and recovery, a relatively low rejection rate, and superior refractive stability. In this study, we examined alterations in corneal clarity among patients who underwent DMEK and correlated these densitometry findings with other optical parameters of corneal topography. Methods : The study incorporated 35 eyes from 35 patients who had previously undergone DMEK surgery for pseudophakic bullous keratopathy at Ankara Bilkent City Hospital. The results from these patients were compared with those from a healthy control group. The preoperative and postoperative optical parameters of the patients were assessed using Pentacam Scheimpflug topography (Oculus). Results : We observed significant decreases in corneal densitometry in the 0–2 mm and 2–6 mm zones of the anterior, posterior, central, and total layers at the sixth month postoperatively compared to the preoperative period (P

The corneal endothelium, comprising densely packed corneal endothelial cells (CECs) adhering to Descemet's membrane (DM), plays a critical role in maintaining corneal transparency by regulating water and ion movement. CECs have limited regenerative capacity within the body, and globally, there is a shortage of donor corneas to replace damaged corneal endothelia. The development of a carrier for cultured CECs may address this worldwide clinical need. In this study we successfully manufactured a gelatin nanofiber membrane (gelNF membrane) using electrospinning, followed by crosslinking with glutaraldehyde (GA). The fabricated gelNF membrane exhibited approximately 80% transparency compared with glass and maintained a thickness of 20 µm. The gelNF membrane demonstrated desirable permeability and degradability for a Descemet's membrane analog. Importantly, CECs cultured on the gelNF membrane at high densities showed no cytotoxic effects, and the expression of key CEC functional biomarkers was verified. To assess the potential of this gelNF membrane as a carrier for cultured CEC transplantation, we used it to conduct Descemet's membrane endothelial keratoplasty (DMEK) on rabbit eyes. The outcomes suggest this gelNF membrane holds promise as a suitable carrier for cultured CEC transplantation, offering advantages in terms of transparency, permeability, and sufficient mechanical properties required for successful transplantation. [ABSTRACT FROM AUTHOR]

Francesco Aiello,1 Gabriele Gallo Afflitto,1,2 Giulio Pocobelli,1 Diego Ponzin,3 Carlo Nucci1 1Ophthalmology Unit, Department of Experimental Medicine, University of Rome “Tor Vergata”, Rome, Italy; 2Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, FL, USA; 3Fondazione Banca degli Occhi del Veneto, Venice, ItalyCorrespondence: Francesco Aiello, Department of Experimental Medicine, University of Rome “Tor Vergata”, Via Montpellier 1, Rome, 00133, Italy, Email francescoaiello@hotmail.comAbstract: The coronavirus disease 2019 (COVID-19) pandemic exerted a great impact on medical practice, which was reframed according to the actual needs. Ophthalmological services and procedures including corneal transplantation did not represent an exception. The adoption and implementation of new standard operating procedures as well as of new technologies for remote consultation and smart-working reshaped daily activities of both eye bankers, physicians, researchers, and patients. Regulatory restrictions were issued redefining corneal donor eligibility criteria, as well as handling and harvesting procedures of donor ocular tissues. Surgical schedules underwent an abrupt contraction with prioritization of urgent procedures. Local lockdowns and confinement strategies resulted in both a reduction and redirection of research activities. The evaluation of SARS-CoV-2 colonization of ocular tissues, long-term corneal storage techniques, new disinfection strategies, split corneal transplants and cell-based therapies for the treatment of corneal disease peaked in the pipeline. Aim of this article is to summarizes the overall impact of the pandemic on the corneal transplantation machinery, and the current and future perspectives for the corneal transplant community.Keywords: SARS-CoV-2, COVID-19, eye bank, cornea, cornea transplantation, cornea transplant, basic sciences

The inner structures of the eye are protected by the cornea, which is a transparent membrane exposed to the external environment and subjected to the risk of lesions and diseases, sometimes resulting in impaired vision and blindness. Several eye pathologies can be treated with a keratoplasty, a surgical procedure aimed at replacing the cornea with tissues from human donors. Even though the success rate is high (up to 90% for the first graft in low-risk patients at 5-year follow-up), this approach is limited by the insufficient number of donors and several clinically relevant drawbacks. Alternatively, keratoprosthesis can be applied in an attempt to restore minimal functions of the cornea: For this reason, it is used only for high-risk patients. Recently, many biomaterials of both natural and synthetic origin have been developed as corneal substitutes to restore and replace diseased or injured corneas in low-risk patients. After illustrating the traditional clinical approaches, the present paper aims to review the most innovative solutions that have been recently proposed to regenerate the cornea, avoiding the use of donor tissues. Finally, innovative approaches to biological tissue 3D printing and xenotransplantation will be mentioned.

Tissue engineering (TE) cornea is one of the most potential alternatives to the shortage of corneal donors in cornea transplantation. Sodium alginate (SA) hydrogel is commonly used as scaffold in TE. Herein, we present an approach to construct a composite hydrogel, which with SA fiber skeleton structure for shape retention and gelatin surface modification for water retention. The light transmittance, water retention rate, and swelling rate of hydrogels were characterized, and the tensile mechanical properties were also investigated. Keratinocytes were treated with material extract liquor and the results showed that the gelatin modified SA hydrogel has good cytocompatibility. Furthermore, human corneal stromal fibroblasts (HCSFs) from the lenticules were implanted on the surface of gels, and the SA-gelatin hydrogel significantly improved the adhesion and spreading of HCSFs. Finally, we discussed the improvement and application prospect of the composite hydrogel as cornea equivalents.

Limbal dermoid is a rare congenital lesion that can impair vision and raise aesthetic concerns. Surgery is frequently required to reduce discomfort and enhance visual outcomes. A 20-year-old woman presented with a limbal dermoid measuring 4.5 mm in diameter and half the depth of the stroma. Excision was performed with anterior lamellar keratoplasty (ALK) using a post-Descemet's membrane endothelial keratoplasty graft, which resulted in signs of graft failure. Re-surgery was then performed with post-Descemet's stripping endothelial keratoplasty graft. It yielded a clear graft with good visual acuity. The first corneal graft utilized 95% of the graft thickness to cover 55% of the defect, leading to poor host-donor apposition. The second graft employed 55-65% to cover the same portion of the defect. The proportional thickness of the graft is crucial for a successful ALK. Split cornea transplantation produces respectable results; however, the corneal thickness must be carefully considered. [ABSTRACT FROM AUTHOR]

Purpose. To analyze an algorithm for infectious screening of cadaver corneal donors during corneal processing at the Eye Tissue Bank (ETB) of The Fyodorov Eye Microsurgery Federal State Institution and compare it with the European Eye Bank Association (EEBA) data from 2011 through 2015. Material and methods. Data analysis were done using the ETB in-house donor data registry and EEBA annual directory forms. The extracted data included the number of received eye globes, rates of inconclusive and serological tests for human immunodeficiency virus (type 1 and 2), Hepatitis B and C viruses, and Syphilis. Results. During the analyzed period 3479 eye globes were delivered in the ETB for the processing. Hemolysis caused exclusion for 13.9% (n=486) of corneas in the ETB. In opposite, the EEBA data demonstrated far lower rates of inconclusive tests. The positive serology tests lead to canceling 19.4% (n=676) of the incoming corneas in the ETB. Overall, the rates of positive tests were far higher in comparison with EEBA data. At the ETB, positive serological tests for HIV (type 1 and 2) and Syphilis had low variability annually, while the rates of Hepatitis B increased in 2015. Predomination of Hepatitis C was also noted. Often enough, the blood samples were multiply-infected. Conclusion. Overall, the positive serology and hemolysis were the major contraindications and led to exclusion 33.4% (n=1162) of incoming corneas in the ETB. Serological tests rates for indicated infections were higher in the ETB with predomination of Hepatitis C. An algorithm for infectious screening at the Eye Tissue Bank (ETB) of The S. Fyodorov Eye Microsurgery Federal State Institution was effective in selection of postmortem donors for cornea processing in clinical use.

The corneal endothelium, comprising densely packed corneal endothelial cells (CECs) adhering to Descemet’s membrane (DM), plays a critical role in maintaining corneal transparency by regulating water and ion movement. CECs have limited regenerative capacity within the body, and globally, there is a shortage of donor corneas to replace damaged corneal endothelia. The development of a carrier for cultured CECs may address this worldwide clinical need. In this study we successfully manufactured a gelatin nanofiber membrane (gelNF membrane) using electrospinning, followed by crosslinking with glutaraldehyde (GA). The fabricated gelNF membrane exhibited approximately 80% transparency compared with glass and maintained a thickness of 20 µm. The gelNF membrane demonstrated desirable permeability and degradability for a Descemet’s membrane analog. Importantly, CECs cultured on the gelNF membrane at high densities showed no cytotoxic effects, and the expression of key CEC functional biomarkers was verified. To assess the potential of this gelNF membrane as a carrier for cultured CEC transplantation, we used it to conduct Descemet’s membrane endothelial keratoplasty (DMEK) on rabbit eyes. The outcomes suggest this gelNF membrane holds promise as a suitable carrier for cultured CEC transplantation, offering advantages in terms of transparency, permeability, and sufficient mechanical properties required for successful transplantation.

Deepinder K Dhaliwal,1 Viktor Chirikov,2 Jordana Schmier,2 Sanika Rege,2 Schalon Newton3 1Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; 2OPEN Health Evidence & Access, Bethesda, MD, USA; 3Trefoil Therapeutics, Inc., San Diego, CA, USACorrespondence: Schalon Newton, Trefoil Therapeutics, Inc., 6330 Nancy Ridge Dr Suite 103, San Diego, CA, 92121, USA, Tel +1 949 678 9572, Email snewton@trefoiltherapeutics.comPurpose: To assess the incremental burden of corneal transplant surgery for US commercially insured patients with Fuchs endothelial corneal dystrophy (FECD) treated with endothelial keratoplasty (EK) compared to controls.Methods: The study design was retrospective cohort using IBM® MarketScan® claims (January 2014–September 2019) and included EK-treated (N=1562) and control patients (N=23,485) having ≥ 12 months’ enrollment before and after diagnosis, who were subsequently matched on select characteristics. The index date was the beginning of the pre-operative period (3 months before EK); synthetic EK index was assigned for controls. All-cause, eye-disease, and complication-related healthcare resource utilization (HCRU) and costs were compared up to 36 months post index. For a small subset of patients, patient data were linked to the Health and Productivity Management supplemental database, which integrates data on productivity loss and disability payments.Results: Matched cohorts included 804 EK-treated and 1453 controls with average age 65.7 years, 1383 (61%) female. Over 12 months of follow-up, all-cause ($41,199 vs $20,222, p< 0.001) and eye-disease related costs ($22,951 vs $1389, p< 0.001) were higher among EK-treated patients than controls. The cost differential increased additionally by $1000–$2000 per annum by 36 months of follow-up. While balanced at baseline, over follow-up EK-treated patients had higher prevalence of glaucoma, elevated intraocular pressure, cataract, cataract surgery, diagnosis of cornea transplant rejection, retinal edema. By 36 month of follow-up, EK-treated patients had 9 more short-term disability days, resulting in $2992 additional burden of disability payments.Conclusion: This study found a higher cost burden among FECD patients receiving EK treatment versus those who did not. With a shift in management of FECD, cost burden estimates generated in this study could serve as an important benchmark for future studies.Keywords: cornea transplantation, cost analysis, glaucoma, retrospective study

Introduction: The cure of corneal blindness requires manifold increase in the rate of eye donation. The present study was undertaken to assess the knowledge and attitude about eye donation among medical students. A secondary objective of the study was to assess the impact of knowledge of eye donation after studying ophthalmology among the final year students of the MBBS (Bachelor of Medicine Bachelor of Surgery) graduation course. Aim: To assess knowledge and attitude about eye donation among first, second and final year medical students. Also, to assess the impact of studying 'Ophthalmology' on their knowledge. Materials and Methods: A cross-sectional study was conducted by collecting information on a predesigned, structured questionnaire on 'Google forms' and sending a soft copy to 601 students of two medical colleges i.e, GGS Medical College, Faridkot and Dayanand Medical College, Ludhiana, Punjab, India, by email, from March 2019 to April 2019. There were questions about awareness and source of information about eye donation in medical students, knowledge of criteria, and willingness to donate eyes. Responses were accepted till a period of seven days. Students were divided into two groups; group A (n=320 students) with 165 students in first professional year and 155 in second professional year, who had not studied Ophthalmology. Group B (n=281 students) with 142 students in final (part I) professional year and 155 in final (part II) professional year, who had/were studying Ophthalmology. Results were analysed and compared using Chi-square test. Results: Out of 601 students, 527 responded (272 of group A and 255 of group B). The results on knowledge and willingness to donate eyes were quite encouraging. Most of the questions were answered by more than 400 students. Majority of students cited teachers/friends as their source of knowledge. However, there was a saw significant gaps in knowledge in the students, specially before reading Ophthalmology (p-value<0.05). Conclusion: More efforts in the form of counselling techniques, short trainings, videos, need to be put into medical curriculum, ophthalmology teaching and short in-job trainings to make the MBBS students an important link in increasing cornea retrieval. [ABSTRACT FROM AUTHOR]

Introduction: The cure of corneal blindness requires manifold increase in the rate of eye donation. The present study was undertaken to assess the knowledge and attitude about eye donation among medical students. A secondary objective of the study was to assess the impact of knowledge of eye donation after studying ophthalmology among the final year students of the MBBS (Bachelor of Medicine Bachelor of Surgery) graduation course. Aim: To assess knowledge and attitude about eye donation among first, second and final year medical students. Also, to assess the impact of studying ‘Ophthalmology’ on their knowledge. Materials and Methods: A cross-sectional study was conducted by collecting information on a predesigned, structured questionnaire on ‘Google forms’ and sending a soft copy to 601 students of two medical colleges i.e, GGS Medical College, Faridkot and Dayanand Medical College, Ludhiana, Punjab, India, by email, from March 2019 to April 2019. There were questions about awareness and source of information about eye donation in medical students, knowledge of criteria, and willingness to donate eyes. Responses were accepted till a period of seven days. Students were divided into two groups; group A (n=320 students) with 165 students in first professional year and 155 in second professional year, who had not studied Ophthalmology. Group B (n=281 students) with 142 students in final (part I) professional year and 155 in final (part II) professional year, who had/were studying Ophthalmology. Results were analysed and compared using Chi-square test. Results: Out of 601 students, 527 responded (272 of group A and 255 of group B). The results on knowledge and willingness to donate eyes were quite encouraging. Most of the questions were answered by more than 400 students. Majority of students cited teachers/friends as their source of knowledge. However, there was a saw significant gaps in knowledge in the students, specially before reading Ophthalmology (p-value

Penetrating keratoplasty (PKP) yields excellent results for restoring vision in end-stage corneal diseases. However, its success is limited to high-risk diseases such as aniridia, chemical burns, autoimmune corneal diseases, and herpetic eye disease. Boston type 1 keratoprosthesis (BKPro) offers another option to these patients. Since 1992, improvements in perioperative management and device construction have significantly increased the use of BKPro worldwide and challenged the therapeutic role of PKP in these patients. This review aims to evaluate BKPro's place in the treatment algorithm of these high-risk patients to assist surgeons' decision-making. PKP and BKPro are compared in three outcome categories: visual acuity, graft retention and failure, and complications profile. Special attention is given to comparing secondary BKPro versus repeated PKP as well as primary BKPro versus primary PKP. We conclude that secondary BKPro bears a better prognosis than repeated PKP in most high-risk patients. Similarly, primary BKPro likely confers improved outcomes over primary PKP in most high-risk recipients. However, current evidence is based on retrospective designs, and controlled prospective randomized trials are required to validate these conclusions. [ABSTRACT FROM AUTHOR]

We reported a simple, effective, and exceptional blocking technique to prevent possible complications during penetrating re-keratoplasty. A 54-year-old female patient was admitted to the clinic with the complaint of opening corneal surgical wound. After careful corneal dissection from the graft host wound dehiscence, the intraocular lens implantation was tried. However, the vitreous pressure blocked the intraocular lens placement. We decided to do cross sutures to prevent both vitreous pressure and intraocular lens stabilization to finish the corneal transplantation. After the transplantation, the sutures were removed easily and the surgery completed successfully. [ABSTRACT FROM AUTHOR]

Purpose: The p.(Leu450Trp) COL8A2 mutation, associated with an early-onset corneal endothelial dystrophy, can result in bullous keratopathy within the first few decades of life. People with this condition frequently experience anterior corneal changes in keratometry as the disease worsens, which may potentially affect refractive error after endothelial keratoplasty. We describe outcomes of the first cases of Descemet Membrane Endothelial Keratoplasty (DMEK) for patients with known mutations in this gene. Observations: Four eyes from two patients with COL8A2-associated corneal dystrophy underwent DMEK for this condition at a tertiary academic center. Preoperative and postoperative Scheimpflug imaging and manifest refraction was conducted. Mean central corneal thickness decreased from 713 μm preoperatively to 529 μm at one month. Despite long-standing corneal haze, all eyes reached between 20/20 and 20/30 best corrected visual acuity, and minimum postoperative central corneal thickness reached 482, 479, 479 and 533 μm. Refractive changes frequently occurred during the first postoperative year, with 3.6 D, 3.3 D, 3 D, and 0.8 D shifts in spherical equivalent taking place within this time period in the four eyes. Conclusions and Importance: In two patients with the p.(Leu450Trp) mutation in COL8A2 who underwent DMEK, resolution of corneal edema resulted in centrally thin corneas and refractive shifts postoperatively. Despite chronic edema, excellent visual acuity was achieved in all eyes.

Abstract Background Explanted corneae are highly needed for the surgical management of patients with severe corneal diseases. The aim of this study was to determine whether the body donors from the Institute of Anatomy are a suitable source of donor corneae. Methods At the Institute of Anatomy at Saarland University Medical Center in Homburg, corneae are prelevated from body donors who had consented to the removal of tissues for transplantation purposes during their lifetime. Following the report of death, the LIONS Eye Bank is informed and the contraindications of corneal explantation are clarified. Obtaining a blood sample within 24 h postmortem is mandatory. Results The Institute of Anatomy had 150 body donors in the time period from January 2018 to June 2019. Out of these, 68 (45.3%) were reported to the Eye Bank. The age of the donors (median 82 years (range: 57–96)) is not critical since the quality of the corneae depends on the number of endothelial cells (mean: 2109 ± 67 cells/mm2 (range: 511–2944 cells/mm2)). Contraindications were present in 19 (12.6%) cases. The corneae were extracted from 49 (32.7%) body donors. Out of these 98 corneae, 46 (46.9%) were successfully transplanted. Of all non-transplanted corneae, 6 (6.1%) were microbiologically contaminated, 10 (10.2%) had a positive serology, 22 (22.5%) had an endothelial cell count

Purpose: The aim of this study is to evaluate the quality and readability of corneal transplant websites., Methods:  We examined internet resources related to corneal transplantation. The search terms "cornea transplantation," "keratoplasty," "keratoprothesis," and "eye transplantation" were searched on www.google.com. A total of 200 websites were scanned, with 50 websites for each search term. In the final evaluation, 113 websites were included in the study. DISCERN and the Journal of the American Medical Association (JAMA) scales were used to evaluate the websites' quality. The Flesch-Kincaid Grade Level (FKGL) and Simple Measure of Gobbledygook (SMOG) were used to evaluate the readability of the information. The presence of the Health On the Net Foundation Code of Conduct (HONCode) certification on websites was examined in terms of quality., Results: The total DISCERN score was 42.47 ± 17.06, and the score for the JAMA was 1.58 ± 1.52. The FKGL and SMOG scores were found to be 9.19 ± 2.08 and 8.20 ± 5.23, respectively. Most of the websites we examined related to corneal transplantation were profit websites. These websites had low JAMA and DISCERN scores but relatively high readability levels. They were sites that provided low-quality information and had more financial bias and conflict of interest. Journal and book websites were found to have higher readability scores. Journal and book-sourced websites with higher FKGL and SMOG scores were more difficult to read., Conclusion: Most of the websites exhibit financial bias, and as a result, they contain low-quality information. Online information must be more regulated for patients to easily access accurate, high-quality information., Competing Interests: Human subjects: All authors have confirmed that this study did not involve human participants or tissue. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Mesen et al.)

Objectives: To show donation data, number of keratoplasties and the changes in transplant indications and techniques that occurred in Andalusia in the period from 2013 to 2022., Materials and Methods: The present work is a retrospective and descriptive study that included all keratoplasties performed between January 2013 and December 2022 in Andalusia, as well as the evolution of the cornea donation and transplant activity of the public and private hospitals pertaining to the waiting list management system of the Public Health System of Andalusia. Transplants performed in private centers with corneas from outside Andalusia were excluded., Results: Cornea donation activity in Andalusia in the decade 2013-2022 has experienced a growth of more than 126%, while overall transplant activity has increased by 157% in public hospitals. Penetrating keratoplasty has decreased from 83% in 2013 to 43% in 2022, while lamellar techniques have increased from 17% to 57% in this same period. Since 2018, more lamellar transplants are performed than penetrating transplants. Regarding indications, endothelial conditions already represent the first cause of transplantation. In 2022 alone, the public Andalusian Eye Banks evaluated 1,054 corneas and prepared 281 endothelial grafts., Conclusion: In the decade from 2013 to 2022 in Andalusia there has been an increase in donation activity and the number of keratoplasties. The public Eye Banks implementation in this period has played a key role in the widespread adoption of lamellar keratoplasty techniques and has enabled the transition to perform a greater number of lamellar keratoplasties compared to penetrating keratoplasty., (Copyright © 2024 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.)

Background/aims: Corneal endothelial cell loss contributes to transplant failure. Autologous plasma products (APP) activate salvaging pathways that can prevent oxidative stress perioperatively. This study aimed to evaluate the safety of intraoperative incubation of full-thickness corneal grafts in platelet-rich plasma (aPRP) and plasma rich in growth factors (PRGF-Endoret) in mitigating postoperative corneal endothelial cell loss (ECL)., Methods: Pilot study including patients undergoing penetrating keratoplasty (PK) for various indications between June 2021 and December 2022. Patients were randomly assigned to receive either aPRP or PRGF-Endoret incubation, while those who declined intervention served as the control group. Demographic and clinical data were collected, including preoperative and postoperative endothelial cell count, intraocular pressure, pachymetry, and adverse reactions., Results: Thirty individuals who underwent PK completed follow-up: eight from the aPRP group, 10 from the PRGF-Endoret group, and 12 from the control group. No adverse events related to APP treatment were recorded. In the first and third postoperative months, the APP group had significantly lower ECL percentages (37% vs. 25%, p  = 0.02, and 44% vs. 33%, p  = 0.02, respectively); this trend was maintained in the sixth month. When stratified, the PRGF-Endoret group showed significant differences in ECL reduction compared to controls at both time points ( p  = 0.03 and p  = 0.05, respectively). The aPRP group showed a similar statistically significant outcome exclusively on the third postoperative month ( p  = 0.04). APP tended to reduce corneal edema faster than controls. Hexagonality was significantly better in the APP groups in the first and third months, particularly in the PRGF-Endoret group ( p  < 0.005)., Conclusion: Preoperative incubation with APP is safe and promotes better endothelial cell quality and quantity in the early postoperative period following PK. These findings suggest a potential clinical benefit in enhancing graft outcomes and warrant further investigation., Competing Interests: EO: J&J, Alcon, and Allergan. BS-C and EA: BTI-health. AS: Brill Pharma, Abbvie, and GlaxoSmithKline. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Mercado, Hernández, Lopez-Rojas, De La Sen-Corcuera, Anitua, Barraquer, Gutiérrez, Otero and Sabater.)

Objective: This study aims to assess visual anatomic outcomes and complications of Descemet Membrane Endothelial Keratoplasty (DMEK) combined with phacoemulsification and intraocular lens implantation in patients with coexisting endothelial dysfunction and cataract. Methods: Triple DMEK (DMEK with simultaneous cataract surgery) was performed in 39 eyes of the 32 patients. Best-corrected Visual Acuity (BCVA), Endothelial Cell Density (ECD), Central Corneal Thickness (CCT), Refractive Spherical Equivalent (RSE), air injections (Re-bubbling) frequency and complications were assessed preoperatively and postoperative months 1, 3, 6 and 12. Results: BCVA increased from 1.22±0.32 logMAR preoperatively to 0.19±0.18 (n=33) and 0.11±0.09 (n=27) at six months and 12 months after surgery, respectively (p<0.05; Wilcoxon test). The mean ECD of donor corneas decreased from 2771±284 cell/mm² (n=39) to 1401±270 cell/mm² (n=32) after six months and to 1373±217 cell/mm² (n=24) after 12 months (p<0.05). Preoperative CCT decreased from 696±99 μm and to 518±42 μm and 517±35 μm 6 and 12 months after surgery, respectively (p<0.05). The mean RSE was -0.57±0.69 D (n=21) preoperatively and +0.47±0.65 D (n=31) and 0.48±0.67 D (n=27) 6 and 12 months after surgery. The mean RSE was detected ≤1D in 82% of the patients at 12th month. Re-bubbling was performed once in seven eyes (17.9%) and twice in two eyes (5.12%). Re-DMEK was performed in six of seven eyes of which graft failure developed, whereas penetrating keratoplasty was performed in one eye. Conclusion: Triple DMEK may consistently give predictable refractive results without adverse endothelial function. Hence, triple DMEK can be considered as the primary treatment approach in cases with endothelial dysfunction and cataract. [ABSTRACT FROM AUTHOR]

Background: Keratoconus (KCN) is characterized by gradual thinning and steepening of the cornea, which can lead to significant vision problems owing to high astigmatism, corneal scarring, or even corneal perforation. The detection of KCN in its early stages is crucial for effective treatment. In this review, we describe current advances in the diagnosis and treatment of KCN., Methods: This narrative review focuses on recent advancements in the diagnosis and treatment of KCN, especially evolving approaches and strategies. To ensure the inclusion of the most recent literature, relevant publications discussing advanced imaging techniques and treatment options for KCN were extensively gathered from the PubMed/MEDLINE and Google Scholar databases. The following index terms and keywords were used for the online search: keratoconus, diagnosis of keratoconus, advances in the diagnosis of keratoconus, topography or tomography, anterior segment optical coherence tomography, treatment of keratoconus, advances in the treatment of keratoconus, collagen crosslinking, intrastromal ring, keratoplasty, and new techniques in keratoconus., Results: Various screening methods such as corneal topography, tomography, anterior segment optical coherence tomography, and assessment of corneal biomechanics have been developed to identify KCN in its early stages. After diagnosis, KCN management focuses on preventing disease progression. Corneal collagen crosslinking is a minimally invasive treatment that can slow or stop the progression of the condition. Recent research has also explored the use of copper sulfate eye drops (IVMED-80) as a noninvasive treatment to prevent the progression of KCN. Current treatment options for visual improvement include scleral lenses, intracorneal ring segments, corneal allogeneic intrastromal ring segments, and deep anterior lamellar keratoplasty. Recently, novel alternative procedures, such as isolated Bowman layer transplantation, either as a corneal stromal inlay or onlay, have demonstrated encouraging outcomes. Artificial intelligence has gained acceptance for providing best practices for the diagnosis and management of KCN, and the science of its application is contentiously debated; however, it may not have been sufficiently developed., Conclusions: Early detection and advancements in screening methods using current imaging modalities have improved diagnosis of KCN. Improvement in the accuracy of current screening or diagnostic tests and comparison of their validities are achievable by well-designed, large-scale, prospective studies. The safety and effectiveness of emerging treatments for KCN are currently being investigated. There is an ongoing need for studies to track progress and evaluate clinicians' knowledge and practices in treating patients with KCN. Artificial intelligence capabilities in management approach considering the currently available imaging modalities and treatment options would best benefit the patient., Competing Interests: None., (© Author(s).)

Tissue donation is important to reverse cornea‐related blindness. Unfortunately, the willingness to make a decision concerning organ and tissue donation while still alive remains low despite all efforts. By analyzing anonymized archived data from 25 654 next‐of‐kin interviews from our database over a period of 5 years (2013‐2018), it was found that only 20.8% of all potential cornea donors have declared their own wishes. While still alive, refusal was communicated more often than consent by potential donors. Overall consent rates were 39.2%, with parents and siblings consenting more often than other relatives and females refusing more often than male family members. Personal interviews and interviews via telephone handled by staff known to the family resulted in better consent rates (up to 75.6%) with male interviewers receiving higher consent rates in general. The gender of the approached relatives in relation to a male/female interviewer was of low importance. The results also show that it is important to allow discussion about that topic between family members—the more relatives that were involved the higher the probability of consent. [ABSTRACT FROM AUTHOR]

Corneal opacity is a leading cause of reversible blindness worldwide. An electronic corneal prosthesis, or intraocular projector, could potentially restore high-quality vision without need for corneal clarity. Four intraocular projection systems were constructed from commercially available electronic components and encased in biocompatible plastic housing. They were tested for optical properties, biocompatibility, heat dissipation, waterproofing, and accelerated wear. A surgical implantation technique was developed. Intraocular projectors were produced of a size that can fit within the eye. Their optics produce better than 20/200 equivalent visual acuity. MTT assay demonstrated no cytotoxicity of devices in vitro. Temperature testing demonstrated less than 2°C increase in temperature after 1 h. Three devices lasted over 12 weeks under accelerated wear conditions. Implantation surgery was demonstrated via corneal trephination insertion in a cadaver eye. This is the first study to demonstrate and characterize fully functional intraocular projection systems. This technology has the potential to be an important new tool in the treatment of intractable corneal blindness. [ABSTRACT FROM AUTHOR]

Purpose: Acanthamoeba (AA) keratitis is a rare and severe infection with poor prognosis. The aim was to investigate the incidence and risk factors of AA keratitis in a large tertiary ophthalmology department in Denmark. Methods: A search was performed in our electronic patient records by the keywords: 'PHMB/polyhexanid', 'Brolene' or 'amoeba and chlorhexidine' from year 1994 to 2018, and afterwards medical records were reviewed. A total of 65 cases of AA keratitis were hereby identified. Results: Patients were relatively young, median (range) age of 38 (15–70) years. A significant increase of diagnosing AA keratitis occurred from 0.13 cases per million per year in the first 5 years to 2.7 cases per million per year the last 5 years. Eighty‐nine per cent of patients were contact lens users, and 49% had received corticosteroids before the diagnosis was established. Severe pain was present in 34% of patients. Prognosis was poor with final visual acuity of logMAR (mean, 95% CI) 0.30 (0.18–0.41), 18% had transplantation à chaud, and 2% were enucleated. Conclusion: The study indicates that the incidence of AA keratitis is increasing, also in Denmark. Most patients were young contact lens users. The course of the disease is long and often painful, and the prognosis is poor despite relevant treatment. [ABSTRACT FROM AUTHOR]

Background: Explanted corneae are highly needed for the surgical management of patients with severe corneal diseases. The aim of this study was to determine whether the body donors from the Institute of Anatomy are a suitable source of donor corneae.Methods: At the Institute of Anatomy at Saarland University Medical Center in Homburg, corneae are prelevated from body donors who had consented to the removal of tissues for transplantation purposes during their lifetime. Following the report of death, the LIONS Eye Bank is informed and the contraindications of corneal explantation are clarified. Obtaining a blood sample within 24 h postmortem is mandatory.Results: The Institute of Anatomy had 150 body donors in the time period from January 2018 to June 2019. Out of these, 68 (45.3%) were reported to the Eye Bank. The age of the donors (median 82 years (range: 57-96)) is not critical since the quality of the corneae depends on the number of endothelial cells (mean: 2109 ± 67 cells/mm2 (range: 511-2944 cells/mm2)). Contraindications were present in 19 (12.6%) cases. The corneae were extracted from 49 (32.7%) body donors. Out of these 98 corneae, 46 (46.9%) were successfully transplanted. Of all non-transplanted corneae, 6 (6.1%) were microbiologically contaminated, 10 (10.2%) had a positive serology, 22 (22.5%) had an endothelial cell count < 2000 cells/mm2 and 6 (6.1%) are at time of this analysis still in culture medium. The non-transplanted tissues were used for research.Conclusions: Explanted corneae from the Institute of Anatomy are a valuable option in obtaining grafts for corneal transplantation, which is why we are working toward on expanding cooperation with this department. [ABSTRACT FROM AUTHOR]

Background Corneal diseases are the fourth most common cause of blindness worldwide. In the majority of these diseases, vision reduction is reversible and can be restored to a large extent by replacing the cornea through specific surgery and, in particular, transplantation. In Greece, due to a lack of organized eye banks as well as donors, the grafts intended for corneal transplantation usually come from eye banks abroad. This study focuses on the dynamics of cost versus value in the decision-making process for the procurement of corneal grafts, ultimately investigating the safety that the procured grafts provide to patients. Methodology A total of 267 patients with severe vision problems who underwent 301 corneal and amniotic membrane transplants from years 2020 to 2023 at the Transplant Unit of the Athens General Hospital "Georgios Gennimatas" were included in this study. All patients who were deemed appropriate to undergo corneal transplant operations, the diagnosis that led to the specific surgery, and other relevant data were recorded and evaluated. Results There was no significant difference in the ratio between males and females (51.3% male and 48.7% female). The mean age of the patients was 66.5 years (SD = 13.7 years). Graft problems were faced by 13.9% of the patients, with the amniotic membrane by 1.5% (in the total number of surgical operations) and both eyes by 4.5% of patients. The majority of the patients had undergone only one surgery (88.8%). Reoperation was needed in 14% of the cases, and 7.6% of the cases were surgeries that occurred due to graft rejection or non-functioning grafts from surgeries performed at another hospital or clinic. In the majority of surgeries (60.8%), a Descemet's stripping automated endothelial keratoplasty graft was used. The mean cost was 3,167 euro (SD = 960.3 euro). Furthermore, in 35.8% of the surgeries, the graft was preserved with amphotericin. Conclusions The present study draws useful conclusions about the effectiveness of surgical interventions through the correlation of cost and safety of the grafts that are approved and finally used in corneal transplants, as well as the submission of proposals to improve the procedures and lead to patient benefits., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Kousiouris et al.)

Purpose: The ex-vivo feasibility of creating corneal ring segments (ICRS) from biological tissue (xenograft porcine cornea) and combining intra-corneal implantation with Corneal CrossLinking (CXL). Methods: The ring segments from gamma-irradiated porcine donor cornea were shaped and implanted in human cadaver host cornea using a femtosecond laser for their dissection and host cornea channel preparation. Intra-channel 0.25% riboflavin solution combined with higher fluence CXL of 15 joules total energy followed their implantation. Anterior segment Optical Coherence Tomography (OCT), Scheimpflug tomography and Placido-disc topography were used to monitor the positioning and refractive effect. Results: The novel xenograft ring segments were positioned as planned at 85% corneal depth and mid-peripheral, with documented, up to 7 diopters central cornea flattening. Conclusion: Xenograft intracorneal ring segments combined with CXL may offer an alternative to the synthetic materials used clinically so far, aiming in reducing complications of intracorneal opaque deposit accumulation, segment migration, corneal erosion and potential extrusion. Combining CXL may enhance their refractive effect and stabilize potential or documented host ectasia. [ABSTRACT FROM AUTHOR]

Objective of the work is to investigate stress and deformation that conrneal tissue and donor graft undergo during endothelial keratoplasty. In order to attach the donor graft to the cornea, different air bubble pressure profiles acting on the graft are considered. This study is carried out by employing a three-dimensional nonlinear finite element methodology, combined with a contact algorithm. The ocular tissues are treated as isotropic, hyper-elastic and nearly-incompressible materials. The contact algorithm, based on the penalty-based node-to-surface approach, is used to model the donor graft-corneal interface region. First, the proposed computational methodology is tested against benchmark data for bending of the plates over a cylinder. Then, the influence of geometrical and material parameters of the graft on the corneal contact-structural response is investigated. The results are presented in terms of Von Mises stress intensity, displacement and mean contact force. Results clearly indicate that the air bubble pressure plays a key role in the corneal stress and strain, as well as graft stiffness and thickness. [ABSTRACT FROM AUTHOR]

High-risk cornea transplant recipients represent a patient population with significant un-met medical need for more effective therapies to prevent immunological graft rejection due to heightened anti-donor immune response. In this study, a rat model of pre-existing anti-donor immunity was developed in which corneal allografts were rejected earlier than in non-pre-sensitized recipients. In this model, third-party (non-donor, non-recipient strain) allogeneic mesenchymal stromal cells (allo-MSC) were administered intravenously 7 and 1 days prior to transplantation. Rejection-free graft survival to 30 days post-transplant improved from 0 to 63.6% in MSC-treated compared to vehicle-treated control animals (p = < 0.0001). Pre-sensitized animals that received third-party allo-MSC prior to transplantation had significantly higher proportions of CD45+CD11b+ B220+ monocytes in the lungs 24 h after the second MSC injection and significantly higher proportions of CD4+ FoxP3+ regulatory T cells in the graft-draining lymph nodes at the average day of rejection of control animals. In in vitro experiments, third-party allo-MSC polarized primary lung-derived CD11b/c+ myeloid cells to a more anti-inflammatory phenotype, as determined by cytokine profile and conferred them with the capacity to suppress T cell activation via prostaglandin E2 and TGFβ1. In experiments designed to further validate the clinical potential of the protocol, thawed cryopreserved, third-party allo-MSC were shown to be similarly potent at prolonging rejection-free corneal allograft survival as their freshly-cultured counterparts in the pre-sensitized high-risk model. Furthermore, thawed cryopreserved third-party allo-MSC could be co-administered with mycophenolate mofetil without adversely affecting their immunomodulatory function. In conclusion, a clinically-relevant protocol consisting of two intravenous infusions of third-party allo-MSC during the week prior to transplantation, exerts a potent anti-rejection effect in a pre-sensitized rat model of high-risk corneal allo-transplantation. This immune regulatory effect is likely to be mediated in the immediate post-transplant period through the promotion, by allo-MSC, of alternatively-activated macrophages in the lung and, later, by enhanced regulatory T-cell numbers.

Purpose: Optisol GS and Life4C are corneal storage media used by eye banks worldwide. We sought to determine if either solution was associated with superior corneal endothelial cell density (ECD) or morphology in a large cohort of donor corneas., Methods: From January 2016 through December 2020, 10,316 corneas from 5,624 unique donors were acquired and analyzed at Rocky Mountain Lions Eye Bank. In April 2019, Life4C replaced Optisol GS as the sole storage medium. We compared ECD and morphology before and after April 2019, and excluded corneas processed within the transition period. Univariable and multivariable regression analyses accounted for age, sex, tobacco use, heavy alcohol use, and diabetes. Only right corneas were analyzed to account for the correlation between eyes., Results: Of 5042 right corneas analyzed, 3486 were stored in Optisol GS and 1556 in Life4C. There was no significant difference in ECD across groups (2794 vs. 2793 cells/mm 2 in Optisol GS and Life4C, p=0.88). In multivariate analyses, there was no significant difference in corneal ECD (0.6 cells/mm 2 higher with Life4C, p=0.96) or hexagonality (0.22% higher with Life4C, p=0.31). However, the coefficient of variation was significantly lower in the Life4C group (-0.0039, p=0.03). After adjustment for above factors, corneas in Life4C demonstrated a 3.1% decreased likelihood of exhibiting CV values greater than 0.40 (p=0.009)., Conclusions: This study demonstrates comparable and favorable outcomes using both storage media and confirms their overall efficacy. The decreased CV in Life4C is not of clinically significant magnitude, but merits further research in clinical and long-term settings., Competing Interests: Conflicts of Interest and Sources of Funding. The authors have no conflict of interest to disclose. NIH L30 EY024746 (AOE)

High-risk cornea transplant recipients represent a patient population with significant un-met medical need for more effective therapies to prevent immunological graft rejection due to heightened anti-donor immune response. In this study, a rat model of pre-existing anti-donor immunity was developed in which corneal allografts were rejected earlier than in non-pre-sensitized recipients. In this model, third-party (non-donor, non-recipient strain) allogeneic mesenchymal stromal cells (allo-MSC) were administered intravenously 7 and 1 days prior to transplantation. Rejection-free graft survival to 30 days post-transplant improved from 0 to 63.6% in MSC-treated compared to vehicle-treated control animals (p = < 0.0001). Pre-sensitized animals that received third-party allo-MSC prior to transplantation had significantly higher proportions of CD45+CD11b+ B220+ monocytes in the lungs 24 h after the second MSC injection and significantly higher proportions of CD4+ FoxP3+ regulatory T cells in the graft-draining lymph nodes at the average day of rejection of control animals. In in vitro experiments, third-party allo-MSC polarized primary lung-derived CD11b/c+ myeloid cells to a more anti-inflammatory phenotype, as determined by cytokine profile and conferred them with the capacity to suppress T cell activation via prostaglandin E2 and TGFβ1. In experiments designed to further validate the clinical potential of the protocol, thawed cryopreserved, third-party allo-MSC were shown to be similarly potent at prolonging rejection-free corneal allograft survival as their freshly-cultured counterparts in the pre-sensitized high-risk model. Furthermore, thawed cryopreserved third-party allo-MSC could be co-administered with mycophenolate mofetil without adversely affecting their immunomodulatory function. In conclusion, a clinically-relevant protocol consisting of two intravenous infusions of third-party allo-MSC during the week prior to transplantation, exerts a potent anti-rejection effect in a pre-sensitized rat model of high-risk corneal allo-transplantation. This immune regulatory effect is likely to be mediated in the immediate post-transplant period through the promotion, by allo-MSC, of alternatively-activated macrophages in the lung and, later, by enhanced regulatory T-cell numbers. [ABSTRACT FROM AUTHOR]

Introduction: Recipients of corneal transplants are at risk of healthcare-associated infections, which, apart from other causes of surgical site infections, may also occur as a result of the transfer of infected corneal tissue. In this study we assessed the risk of bacterial and fungal infections based on the results of routine microbiological testing of cornea preservation fluid samples.Material and Methods: We examined a total of 725 samples of corneal preservation fluid, obtained during a period of 3 years (2011-2013). Corneal preservation fluid samples were cultured and identified in accordance with standard microbiological methods.Results: The analysis comprised 725 samples of corneal preservation fluid, of which 32 (4.4%) samples tested positively in microbiological cultures. In total, 34 strains of bacteria and fungi were cultured. Gram-positive bacteria, Gram-negative bacteria and fungi comprised 85.3%, 8.8% and 5.9% of these strains, respectively. Analysis of the susceptibility of the cultured bacterial isolates to gentamicin was also performed, as this antibiotic is present in the composition of corneal preservation fluid. Among the cultured bacterial strains, 10 (33.3%) were resistant to gentamicin. None of the 32 patients who received a cornea stored in preservation fluid contaminated with bacteria and/or fungi demonstrated infectious complications in the surgical site within 1 year following cornea transplantation.Conclusions: We postulate that perioperative antibiotic prophylaxis in cornea transplant recipients is important in preventing bacterial infections derived from the donor cornea. We believe that the addition of an antifungal agent to commercially available cornea preservation fluids should also be considered. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the indications for corneal transplantation, the procedures carried out, and the postoperative outcomes and to compare these with previous Irish corneal transplant studies.Methods: A retrospective review of the case notes of all patients who underwent corneal transplantation under the care of a single surgeon, from 2008 to 2015, was performed. The risk factors for postoperative complications including transplant failure were examined.Results: During the period studied, 42 corneal transplant surgeries were carried out on 40 eyes of 38 patients, 24 of whom were male (63%), median age at surgery was 62 years (range 23–96 years). The most common indication for transplantation was pseudophakic corneal decompensation associated with Fuch’s endothelial dystrophy (FED) (n = 13). Seventeen penetrating keratoplasties, 23 lamellar keratoplasties, and two amniotic membrane transplant procedures were carried out. Transplant failure resulting in corneal oedema or repeat corneal transplant surgery (n = 4, 10%), was associated with previous transplant failure in the eye; odds ratio (OR) = 1.58 (p = 0.05), and with comorbid FED, OR = 1.50 (p = 0.02). Intraocular lens opacification occurred in one lens following DSAEK, giving an incidence rate of 7%.Conclusions: Pseudophakic corneal decompensation is the commonest indication for corneal transplant surgery, with lamellar keratoplasty the most frequent approach in our cohort, reflecting developments observed in corneal transplant surgery elsewhere. Prior corneal transplant failure and Fuch’s dystrophy remain important risk factors for failure. The risk of intraocular lens opacification and its potential effects on vision should be elaborated prior to endothelial keratoplasty. [ABSTRACT FROM AUTHOR]

Background: Descemet membrane endothelial keratoplasty (DMEK) is increasingly favored in the treatment of endothelial dysfunction due to its benefits, which include swift visual rehabilitation and recovery, a relatively low rejection rate, and superior refractive stability. In this study, we examined alterations in corneal clarity among patients who underwent DMEK and correlated these densitometry findings with other optical parameters of corneal topography., Methods: The study incorporated 35 eyes from 35 patients who had previously undergone DMEK surgery for pseudophakic bullous keratopathy at Ankara Bilkent City Hospital. The results from these patients were compared with those from a healthy control group. The preoperative and postoperative optical parameters of the patients were assessed using Pentacam Scheimpflug topography (Oculus)., Results: We observed significant decreases in corneal densitometry in the 0-2 mm and 2-6 mm zones of the anterior, posterior, central, and total layers at the sixth month postoperatively compared to the preoperative period (P<0.05). The corneal densitometry values at postoperative month 6 were elevated in all layers and zones relative to the healthy group (P<0.05). The root mean square of higher-order aberrations in postoperative period was elevated significantly (P<0.001)., Conclusions: Six months after operation, the optical quality of the cornea following DMEK surgery did not achieve the level of a healthy cornea.

Tissue engineering (TE) cornea is one of the most potential alternatives to the shortage of corneal donors in cornea transplantation. Sodium alginate (SA) hydrogel is commonly used as scaffold in TE. Herein, we present an approach to construct a composite hydrogel, which with SA fiber skeleton structure for shape retention and gelatin surface modification for water retention. The light transmittance, water retention rate, and swelling rate of hydrogels were characterized, and the tensile mechanical properties were also investigated. Keratinocytes were treated with material extract liquor and the results showed that the gelatin modified SA hydrogel has good cytocompatibility. Furthermore, human corneal stromal fibroblasts (HCSFs) from the lenticules were implanted on the surface of gels, and the SA-gelatin hydrogel significantly improved the adhesion and spreading of HCSFs. Finally, we discussed the improvement and application prospect of the composite hydrogel as cornea equivalents., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Descemet membrane endothelial keratoplasty (DMEK) is an increasingly popular surgical procedure for treating ocular diseases that require a corneal transplant. Previous studies have found that tissue tearing during surgical preparation is more likely elevated in eyes from donors with a history of diabetes mellitus. To quantify these potential differences, we established an experimental technique for quantifying the force required to separate the endothelium-Descemet membrane complex (EDM) from stroma in human donor corneal tissue, and we assessed differences in adhesion strength between diabetic and non-diabetic donor corneas. Transplant suitable corneas were obtained from 23 donors 50–75 years old with an average preservation to assay time of 11.5 days. Corneas were classified from a medical records review as non-diabetic (ND, n = 9), diabetic without evidence of advanced disease (NAD, n = 8), or diabetic with evidence of advanced disease (AD, n = 10). Corneas were sectioned into 3 mm wide strips and the EDM peeled from the stroma. Using the force-extension data obtained from mechanical peel testing, EDM elastic peel tension ( T E ), elastic stiffness ( S E ), average delamination tension ( T D ), and maximum tension ( T MAX ) were calculated. Mean T E , S E , T D , and T MAX values for ND corneas were 0.78 ± 0.07 mN/mm, 0.37 ± 0.05 mN/mm/mm, 0.78 ± 0.08 mN/mm, and 0.94 ± 0.17 mN/mm, respectively. NAD values did not differ significantly. However, AD values for T E (1.01 ± 0.18 mN/mm), T D (1.09 ± 0.21 mN/mm), and T MAX (1.37 ± 0.24 mN/mm) were greater than ND and NAD corneas (P < 0.05). S E did not differ significantly between groups. These findings provide proof of the concept that chronic hyperglycemia from diabetes mellitus results in a phenotypically more adhesive interface between Descemet membrane and the posterior stroma in donor corneal tissue. Results of this study provide a foundation for further investigations into the impact of diabetes on the posterior cornea, eye banking, and keratoplasty. [ABSTRACT FROM AUTHOR]

Background Lymphangiogenesis is one of the major causes of corneal graft rejection. Among the lymphangiogenic factors, vascular endothelial growth factor (VEGF)-C and -D are considered to be the most potent. Both bind to VEGF receptor 3 (VEGFR3) to activate Prospero homeobox 1 (Prox1), a transcription factor essential for the development and maintenance of lymphatic vasculature. MicroRNAs (miRNAs) bind to the 3' untranslated regions (3' UTRs) of target genes in a sequence-specific manner and suppress gene expression. In the current study, we searched for miRNAs that target the pro-lymphangiogenic factor Prox1. Results Among the miRNAs predicted by the bioinformatic analysis to seed match with the 3' UTR of Prox-1, we chose 3 (miR-466, miR-4305, and miR-4795-5p) for further investigation. Both the miR-466 and miR-4305 mimics, but not the miR-4795-5p mimic, significantly reduced the luciferase activity of the Prox-1 3' UTR reporter vector. In primary lymphatic endothelial cells (HDLEC), miR-466 mimic transfection suppressed Prox1 mRNA and protein expression, while miR-4305 mimic transfection did not. Experiments using mutated reporter constructs of the two possible seed match sites on the 3' UTR of Prox1 suggested that the target site 2 directly bound miR-466. HDLEC transfected with the miR-466 mimic suppressed tube formation as compared to the scrambled control. Furthermore, HDLEC transfected with a miR-466 inhibitor showed enhanced tube formation as compared to control inhibitor transfected cells, and this inhibitory effect was counteracted by Prox1 siRNA. The miR-466 mimic reduced angiogenesis and lymphangiogenesis resulting in clearer corneas in an cornea injury rat model compared to the scrambled control. Conclusions Our data suggest that miR-446 may have a protective effect on transplanted corneas by suppressing Prox1 expression at the post-transcriptional level. The results of the current study may provide insights into the mechanisms of lymphangiogenesis resulting from corneal graft rejection and alkali-burn injuries, as well as into the development of new treatments for lymphangiogenic eye diseases. [ABSTRACT FROM AUTHOR]

Descemet membrane endothelial keratoplasty (DMEK) is the most recent iteration of endothelial keratoplasty. With DMEK, restoration of true corneal anatomy is achieved. The majority of outcomes of DMEK surpass those of any of its predecessors - visual acuity, speed of recovery, refractive shift and stability as well as immunologic rejection are all better than before. As surgical techniques are continuously being refined, so endothelial cell densities and complications rates are steadily improving. All of these account for DMEK gaining popularity with corneal surgeons as well as patients suffering from corneal endothelial disease. This review highlights the recent advances in this exciting field of corneal surgery and addresses current challenges and contentious issues. [ABSTRACT FROM AUTHOR]