Keratoplasty Research Articles

Keratoplasty to restore vision in trachomatous corneal opacity: A literature review

Background Trachoma is the leading infectious cause of blindness. Patients with trachomatous corneal opacity (TCO) are traditionally considered high-risk cases for graft failure. However, anecdotal evidence suggests that corneal transplantation may restore vision in such individuals. We wanted to review the available evidence for keratoplasty outcomes in TCO. Methods A literature search of PubMed, MEDLINE, and Web of Science was performed using the search terms “trachoma* AND (keratoplasty OR cornea* transplant*)”. The search was restricted to studies published between 1 January 1992 and 12 October 2022. All types of prospective and retrospective study designs reporting outcomes of keratoplasty in trachoma were included. The primary outcome assessed was rate of graft survival in patients with TCO who received keratoplasty. Secondary outcomes were postoperative best corrected visual acuity (BCVA) and graft rejection rates. Results Seven studies met our inclusion criteria. None were prospective trials; 215/302 grafts (71%) were clear at final follow-up. There was significant variability between studies in the reporting of patient characteristics, follow-up, complications, and outcomes. In data on penetrating keratoplasty (PKP), graft survival at final follow-up was observed in 161/195 eyes (83%). Studies assessing lamellar keratoplasty (LKP) reported graft survival in 18/20 eyes (90%). Rejection episodes were reported in 31/167 (19%) eyes managed with PKP and 0 of 20 eyes managed with LKP. Of 163 eyes, preoperative BCVA was ≤counting fingers in 76% and ≤6/60 in 91%. A postoperative BCVA of >6/60 was achieved in 63% of eyes. Conclusions There is a paucity of evidence supporting keratoplasty in TCO. However, it may hold visual rehabilitation promise for people whose needs have to date been largely ignored. More structured reporting of outcomes from centres which perform keratoplasty in TCO and a well-designed prospective study would be valuable additions to the literature.

Comparison of clinical outcomes, complications and patient satisfaction following deep anterior lamellar keratoplasty and penetrating keratoplasty.

Keratoplasty is a surgical procedure in which a damaged or diseased cornea is replaced with healthy donor tissue, thereby restoring vision. Recent advancements have led to the replacement of penetrating keratoplasty (PKP) with the more selective deep anterior lamellar keratoplasty (DALK) procedure, especially for treating keratoconus. Although DALK typically has a shorter recovery time, less pain and a lower risk of rejection, PKP is still being performed for more severe corneal diseases. A comparative study of clinical profiles, treatment outcomes and patient-reported satisfaction will provide valuable insights into the cost-effectiveness, impact on quality of life and ability of each procedure to treat different pathologies of the cornea. Here, we aimed to compare the clinical and subjective outcomes of DALK with those of the PKP at a single center in the Kingdom of Saudi Arabia. This retrospective cohort study included eyes that underwent either PKP or DALK from January 2017 to January 2021. The demographic features, indications, best corrected visual acuity (BCVA) and complications of the patients were recorded for both groups, analyzed and compared. A subgroup of eyes with keratoconus was analyzed separately and compared to the larger group. A 6-item survey was conducted via telephone to assess patient satisfaction and expectation, and the results were compared between the two procedures. The chi-square test or Fisher's exact test for categorical variables or the t test or Kruskal‒Wallis test for continuous variables were used as appropriate for all comparisons, and the level of significance was set at α = 0.05. A total of 97 patients were included. PKP and DALK were performed on 63 and 39 eyes, respectively. Patients who underwent DALK were younger (mean ± standard deviation 31 ± 10.82 years versus 43 ± 26.89 years for patients who underwent PKP). The most frequent indication for PKP was keratoconus (35.5%); however, in 97.4% of the eyes undergoing DALK, the indication was keratoconus. In both groups, visual acuity and refractive error improved, but the postoperative corrected distance visual acuity in the DALK group (0.3 log MAR) was noticeably greater than that in the PKP group (0.6 log MAR). Compared with PKP, DALK may carry a lower risk of early graft edema and rejection. Overall, the reported postoperative patient satisfaction was similar for both procedures. The findings highlight the effectiveness of PKP and DALK in improving visual acuity and emphasize the importance of considering patient-reported outcomes in evaluating success. DALK has been demonstrated to be beneficial for protecting the corneal endothelium and lowering the risk of complications and graft rejection.

Harnessing Tumor Cell-Derived Exosomes for Immune Rejection Management in Corneal Transplantation.

Transplantation remains the definitive treatment for end-stage organ failures, but its efficacy is frequently compromised by immune rejection. This study introduces a novel strategy by utilizing tumor-derived exosomes from B16-F10 melanoma cells (B16-Exo), diverging from the conventional use of immune cell-derived exosomes, to alleviate post-transplantation immune rejection. Utilizing murine corneal transplantation as a model, it is demonstrated that B16-Exo significantly reduces immune rejection, evidenced by decreased corneal opacity, neovascularization, and immune dysregulation, while enhancing postoperative survival. Proteomic analyses reveal differential expression of pivotal proteins in B16-Exo, notably the JAK2 protein within the JAK-STAT signaling pathway, which has been mechanistically demonstrated to amplify the activity of myeloid-derived suppressor cells (MDSCs) and inhibit T cell proliferation. These findings demonstrate the significant immunomodulatory effect of B16-Exo in transplant immunology, supporting the continued exploration of tumor-derived exosomes as a platform to uncover novel immunosuppressive mechanisms in transplantation.

Real-world data to improve organ and tissue donation policies: lessons learned from the tissue and organ donor epidemiology study.

The transplantation of human organs, and some human tissues, is often the only life-saving therapy available for serious and life-threatening congenital, inherited or acquired diseases. However, it is associated with a risk of transmission of communicable diseases from donor to recipient. It is imperative to understand the characteristics of the donor population(including both potential and actual donors) to inform policies that protect recipient safety. The Tissue and Organ Donor Epidemiology Study (TODES) was a pilot project designed to identify and collect standardized information on deceased persons referred for organ, tissue and/or eye donation, and to estimate (to the extent possible) infectious disease prevalence and incidence of human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) in this population. TODES is summarized here to shed light on addressable limitations on accessing data needed for transplant recipient safety. Limitations, future research needs and potential pathways to solve the remaining data needs are explored. Retrospective data for all deceased donors during a 5-year period from 2009 to 2013 were obtained from participating organ procurement organizations (OPOs), tissue establishments and eye banks. These decedent data were used to ascertain whether the available real-world data (RWD) could be used to inform donor screening and testing policy. The TODES database contains 291848 records received from nine OPOs and 42451 records received from four eye banks. Data were analysed from deceased donors with at least one organ, tissue or ocular tissue recovered with the intent to transplant. Results for potential donors were not analysed. Available RWD at the time of the TODES study were not fit-for-purpose to help characterize the organ, tissue and eye donor populations and/or to inform donor screening policy. Recent advances in electronic data collection systems make it more realistic to now collect fit-for-purpose RWD that address the research needed to improve transplant safety.

A novel sandwich technique of minimally invasive surgery for corneal perforation.

This study aimed to describe a novel sandwich technique of minimally invasive surgical implantation by using corneal stromal lenticules for corneal perforation. This prospective observational study included nine patients aged 23-79 years (mean, 54 ± 9) from Tianjin Eye Hospital. Corneal stromal lenticules with a central thickness of 120μm were obtained from small incision lenticule extraction(SMILE). With the corneal perforation as the central point, an iris-repositor was used to manually create a mid-stromal pocket; the stromal lenticular button was gently inserted into the intrastromal pocket and flattened. The graft was sandwiched between the anterior and posterior corneal stromal pockets; the incision was closed using two sutures. The primary health outcome measured in this study was the logMAR best spectacle-visual acuity at 6 months postoperatively. Corneal perforation closure and anterior chamber formation occurred immediately after surgery. No epithelial implantation, infection, or allogeneic rejection was observed during the follow-up. No patients required a penetrating keratoplasty. Anterior segment optical coherence tomography revealed a mean thickness of the grafted tissue of 122 ± 21μm, with a clear interface in all cases. Comparing the baseline and postoperative 6-month values, the mean logMAR best spectacle-corrected visual acuity was improved from 0.18 ± 0.12 to 0.52 ± 0.31 (P < 0.001). There was significant reduction in the mean manifest spherical equivalent, refractive cylinder, and mean keratometry readings. The novel minimally invasive surgical method for corneal implantation. It was an effective alternative treatment that could restore corneal integrity and improve vision in patients with corneal perforations. This method appears safe, easy, cost- and time-effective, and reliable.

Dupilumab-Associated Bilateral Conjunctival Papillomas and Corneal Perforation.

We report a unique case of significant human papillomavirus-associated conjunctival papillomas and severe corneal ulceration leading to corneal perforation in a patient treated with dupilumab for atopic dermatitis. This study is a case report and literature review of severe corneal side effects related to dupilumab. A 27-year-old man with severe atopic dermatitis and no ocular history was administered dupilumab 300 mg via subcutaneous injections every 2 weeks with an excellent response. Following the onset of treatment, the patient developed conjunctivitis, conjunctival papillomas, and dry eyes, which were initially treated with lubricating eye drops. Fourteen months after commencing dupilumab, he had a rapid onset of painful visual loss in the OD accompanied by severe bilateral conjunctival injection and was found to have a central corneal ulcer and diffuse papillomas on the palpebral and bulbar conjunctiva. Despite management with intravenous methylprednisolone and topical dexamethasone, the patient's corneal ulcer progressed to a corneal melt, resulting in perforation 2 months after diagnosis, which necessitated a corneal graft. We present the third reported case of dupilumab-associated corneal perforation and the first case to our knowledge of dupilumab-associated conjunctival papillomas. As dupilumab usage increases, awareness of these potential complications among prescribers is essential.

Five years of emergency keratoplasty at a tertiary eye hospital.

The aim of this study is to present the results of patients who underwent emergency keratoplasty for tectonic or therapeutic reasons. Medical records of 33 patients who underwent tectonic or therapeutic keratoplasty at Ege University Department of Ophthalmology between January 2019 and January 2024 were retrospectively evaluated. Demographic characteristics, ocular and systemic findings, indications of keratoplasty, size of grafts, need for re-keratoplasty, preoperative treatment modalities, need for additional surgical interventions, and prognosis of the patients were investigated. During this period, 450 penetrating keratoplasty (PK) surgeries were performed and 34 (7.55%) were emergency PK (34 eyes of 33 patients). The mean age of the patients was 65.30 ± 15.40 (40-91). Female to male ratio was 18/15. 17 (50.00%) emergency PKs were performed for tectonic and 17 (50.00%) were performed for therapeutic purposes. Mean follow up time was 24.85 ± 26.62 (2-120) months. A total of 20 (58.82%) eyes required additional surgery, 9 (26.47%) of which required re-keratoplasty with different indications during follow-up. Graft rejection or failure developed in 17 (50.00%) of the eyes in an average of 12.05 (1-45) months. Evisceration was needed in 2 (5.88%) eyes. Despite limited access to donor cornea and high complication rate, emergency keratoplasty is one of the most important options that retain ocular integrity in the treatment of corneal infections and non-traumatic corneal perforations unresponsive to conventional treatment.

Clinical Outcomes of Infectious Keratitis Associated with Contact Lens Wear Following Penetrating Keratoplasty: A Case Series.

To report on the clinical characteristics, and outcomes of patients who developed infectious keratitis associated with contact lens (CL) wear following penetrating keratoplasty (PK). A retrospective chart review was performed to identify all patients who underwent PK between November 2012 and January 2023 at a single tertiary referral practice, and subsequently developed CL related infectious keratitis. 74 patients using CL following PK were identified. Charts were reviewed to obtain data about demographics, ocular history, CL usage, microbial culture reports, visual acuity, treatment, and clinical outcomes. CL-associated infectious keratitis occurred in 9 patients, more frequently in males (66%), and patients had a mean age of 54.5 ± 11.8years old. The identified causative organisms included: Stenotrophomonas maltophilia (N = 3), Candida parapsilosis (N = 2), Moraxella nonliquefaciens (N = 1), Pseudomonas aeruginosa (N = 1), Staphylococcus epidermidis (N = 1), Streptococcus mitis (N = 1), Candida albicans (N = 1), and Acanthamoeba (N = 1). Contact lenses were used following PK for an average of 9.1 ± 10.8months before development of keratitis. Patients were followed for 31.8 ± 30.2months after infection. The mean best corrected visual acuity without CL prior to infection was 20/150 and decreased to 20/260 post-infection. Complications following the contact-lens-associated infectious keratitis included: central corneal haze (N = 8), chronic corneal epithelial defects (N = 3), perforation (N = 3), endophthalmitis (N = 1), and enucleation (N = 1). Three grafts required repeat PK. CL-associated infectious keratitis following PK have high rates of complication. Patients should be monitored closely for signs of infection.

Deep learning based highly accurate transplanted bioengineered corneal equivalent thickness measurement using optical coherence tomography

Corneal transplantation is the primary treatment for irreversible corneal diseases, but due to limited donor availability, bioengineered corneal equivalents are being developed as a solution, with biocompatibility, structural integrity, and physical function considered key factors. Since conventional evaluation methods may not fully capture the complex properties of the cornea, there is a need for advanced imaging and assessment techniques. In this study, we proposed a deep learning-based automatic segmentation method for transplanted bioengineered corneal equivalents using optical coherence tomography to achieve a highly accurate evaluation of graft integrity and biocompatibility. Our method provides quantitative individual thickness values, detailed maps, and volume measurements of the bioengineered corneal equivalents, and has been validated through 14 days of monitoring. Based on the results, it is expected to have high clinical utility as a quantitative assessment method for human keratoplasties, including automatic opacity area segmentation and implanted graft part extraction, beyond animal studies.

Sociodemographic Predictors of Keratoconus (Severity, Treatment, and Progression) in a Tertiary Center in New York City.

To identify sociodemographic factors as predictors of keratoconus severity, progression, disease outcomes, and appropriate management in a tertiary care ophthalmology institute in the New York City metropolitan area. This is a retrospective chart review. Patients with keratoconus presenting at a tertiary eye institute in an urban setting seen between 2015 and 2022 were included. Sociodemographic data including age, sex, race, ethnicity, income derived from zip code, insurance coverage, and preferred language were recorded. These sociodemographic factors were analyzed as possible predictors of keratoconus severity at presentation (Amsler-Krumeich grades III and IV): patients presenting with acute hydrops, patients receiving corneal cross-linking or corneal transplant, patients showing 1 or more diopters of increase of Kmax during their follow-up, and patients having longer time between the provider's recommendation of corneal cross-linking and the time of the procedure. The retrospective review included 634 patients with a clinical diagnosis of keratoconus. Factors associated with severe keratoconus at presentation in the multivariate analysis were non-White (P < 0.001), lowest income (Q1) (P = 0.018), Q2 income (P = 0.012), and having Medicaid/Medicare coverage (P = 0.021). Medicaid/Medicare coverage was the only factor associated with acute hydrops (P < 0.001), and younger age was the only factor associated with disease progression (P < 0.001). Younger patients and patients with commercial insurance coverage were more likely to receive corneal collagen cross-linking (P < 0.001 and P < 0.001, respectively), whereas patients with Medicaid/Medicare coverage, lowest income, and non-White race were more likely to receive corneal transplantation (P = 0.012, P = 0.062, and P = 0.028, respectively). Medicaid/Medicare was the only factor associated with delay in receiving corneal collagen cross-linking (P = 0.013). Our study demonstrates that there are sociodemographic predictors of keratoconus disease severity, progression, and the type and the time of treatment the patients received. This confirms eye health disparities among patients with keratoconus.

A Novel Artificial Endothelial Replacement Membrane for the Treatment of Chronic Corneal Edema.

The purpose of this study was to report the safety and efficacy results of an artificial lamellar implant for the treatment of chronic corneal edema. The EndoArt (EyeYon Medical, Ness Ziona, Israel), an artificial endothelial replacement membrane designed to treat corneal edema, was implanted in 24 eyes of 24 patients with low-to-normal visual potential. We present the safety and efficacy results from a prospective, open-label, single-arm, multicenter study conducted over a 12-month period. Twenty-four patients were enrolled, with no device-related serious adverse events reported. Seventeen patients completed 12-month follow-up, showing a reduction in average central corneal thickness from 759 ± 116 μm to 613 ± 135 μm. Best-corrected distance visual acuity improved from 1.88 ± 0.79 logarithmic minimum angle of resolution (logMAR) to 1.34 ± 0.57 logMAR. Sixty percent gained at least 3 early treatment diabetic retinopathy study (ETDRS) lines. The EndoArt was removed in 5 cases due to incomplete attachment and replaced by corneal transplants; 1 patient was lost to follow-up, and 1 had a procedure failure. No device-related long-term complications, infections, or inflammations were reported. The implants remained transparent throughout the study. The first-in-human results of EndoArt implantation demonstrated the device's potential to treat patients suffering from corneal edema with a favorable safety profile and effective edema reduction in most subjects, with no device-related serious adverse event. The EndoArt may offer a viable solution in regions facing a shortage of donor corneas, as well as for patients who have poor prognosis with human tissue.

The Triple Procedure in Patients with Congenital Aniridia.

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.

Antifungal resistance, clinical outcome and clinico-microbiological correlation in ocular infections due to common melanized fungi Curvularia lunata and Lasiodiplodia theobromae in South India.

Aim. Melanized fungi were rarely studied for their antifungal resistance (AFR) or clinical outcome, despite rising incidence of melanized fungal ocular infections and AFR in general. We report the antifungal resistance patterns, clinical outcome and clinico-microbiological correlation in two commonly isolated melanized fungi from ocular infections, Curvularia lunata and Lasiodiplodia theobromae, at a tertiary eyecare centre in South India.Gap statement. Despite melanized fungi accounting for a significant proportion of ocular fungal infections in the Indian subcontinent, and despite there being a limited selection of effective antifungal agents available for these infections, the existing data and studies on these issues remain sparse. Therefore, this study aimed to investigate the prevalence of antifungal resistance in two of the most common melanized fungal pathogens in ocular infections, Curvularia lunata and Lasiodiplodia theobromae and correlate it with the treatment given and the clinical outcome in patients.Methodology. Electronic medical records provided the clinical data. Standard broth microdilution was performed for antifungal susceptibility testing (AFST) in 30 isolates (17 C. lunata and 13 L. theobromae) for amphotericin B and natamycin (polyenes): voriconazole, ketoconazole, posaconazole, itraconazole and fluconazole (azoles) and caspofungin (echinocandin). Multidrug resistance (MDR) was defined as resistance to more than or equal to two classes of antifungals. DNA sequencing was performed for the isolates for species confirmation. The multivariate analysis was done for determining poor prognostic factors.Results. AFST showed highest susceptibility of study isolates for voriconazole (83.3% isolates), followed by natamycin (80%), fluconazole (80%), itraconazole (76.7%), ketoconazole (70%), posaconazole (66.7%), caspofungin (66.7%) and lastly amphotericin B (63.3%). All patients empirically received topical natamycin; additional oral ketoconazole/intraocular voriconazole was administered in select few. MDR was strongly associated with poor clinical outcome (multivariate analysis: P = 0.03, odds ratio = 7.8). All patients had microbial keratitis, one progressed to endophthalmitis. Additionally, therapeutic penetrating keratoplasty was required in 40% of cases. Globe salvage was possible in 80% patients, though good visual outcome was seen in only half of them. Both, anatomical and visual outcomes, were poor in 20% of patients. DNA sequencing showed C. lunata as the highest study species.Conclusion. C. lunata and L. theobromae showed varying in vitro antifungal susceptibility and clinical outcome in ocular infections. Voriconazole had significantly higher activity, while amphotericin B had lower activity in vitro for these melanized fungi. MDR isolates showed poorer clinical outcome.

TRANSPLANTE DE CÓRNEA, UMA REVISÃO INTEGRATIVA

Currently, cornea transplantation is the transplant performed in the largest number and with the best success rates. This article sought to bring together the main information about corneal transplantation, including indications, procedures and complications, in order to facilitate access to knowledge about this surgery. To this end, an integrative literature review was carried out with six well-defined steps, including defining the guiding question, searching for articles in specific databases and clear inclusion/exclusion criteria. The descriptors “cornea transplant”, “corneal transplant”, “indications”, “procedures” and “complications” were crossed in the following databases: Virtual Health Library (VHL); National Library of Medicine (PubMed MEDLINE), Scientific Electronic Library Online (SCIELO) and EbscoHost. The final selection included 20 articles. The data collected made it possible to identify some characteristics and statistical data on cornea transplantation. The results include main procedures and techniques, indications, risks, complications and epidemiology. The review concluded that the most used procedure is still penetrating keratoplasty, despite the various evolutions observed; The main indications vary from region to region, but overall the most prevalent was bullous keratopathy and the most prevalent complication is graft failure due to rejection.

Scleral lens fitting after paediatric limbal dermoid removal

Purpose. This case report describes the management of refractive error and amblyopia using a scleral lens fitted to the eye of a young child with an irregular cornea resulting from limbal dermoid removal and corneal transplant in infancy. Material and Methods. A young infant was initially fitted with spectacles and occlusion therapy following the surgical excision of a limbal dermoid and full thickness corneal transplant. The vision did not improve in spite of patching so the child was referred for contact lens fitting. Various iterations of scleral lens fitting were carried out. Results. Scleral lens fitting was attempted from the age of 2 years but transplant rejections, the COVID-19 pandemic and variable cooperation meant that adequate lens wear could not be achieved in the early stages. In addition, the corneal shape changed during the course of the fitting. During these periods, spectacle wear and occlusion therapy were maintained until a good lens fit could be achieved following several modifications. Treatment is ongoing but at the age of 5 years, the visual acuity is 0.24 logMAR letters. Conclusion. Scleral lenses can be used to habilitate the vision in an eye with an irregular cornea but when scleral lens wear is not possible, it is important to persevere with spectacle correction and patching therapy. Several iterations of scleral lenses may be needed as the eye changes and the child grows.

Corneal Artificial Endothelial Layer (EndoArt): Literature Review and Our Experience.

Background/Objectives: The objective of this study was to examine the morphological corneal changes and outcomes following the implantation of an artificial endothelial layer (EndoArt) in patients with chronic corneal oedema. Methods: A systematic review of the literature was conducted alongside a detailed analysis of two clinical cases with chronic corneal oedema that were treated using EndoArt. Our experience with these two cases is included to provide practical insights and real-world outcomes. Results: Across the 24 cases reported (including the two presented here), an analysis was possible in 23 cases. Notably, 82% of patients had undergone at least one previous corneal transplant, with 39% having undergone three or more transplants. Additionally, 78% of cases had ocular comorbidities, with glaucoma surgery being the most prevalent (83%), which could have impacted visual outcomes. The follow-up period ranged from 3 to 17 months with a median of 3 months. After EndoArt implantation, the average reduction in the central corneal thickness (CCT) was 29%, and the rebubbling rate was 47.8%, with some cases requiring no rebubbling, while others required it up to 100% of the time. Visual acuity significantly improved from a mean best-corrected visual acuity (BCVA) value of 1.61 ± 0.5 logMAR to 1.07 ± 0.59 logMAR (p < 0.001). The CCT decreased from 771 ± 146 µm to 580 ± 134 µm (p < 0.001). These findings are consistent with our experience. Conclusions: EndoArt shows promise as an alternative treatment for chronic corneal oedema in complex cases where conventional corneal transplantation has failed or carries a high risk of failure. The morphological changes observed using anterior segment optical coherence tomography (OCT) and in vivo confocal microscopy (IVCM) were similar to those reported after endothelial keratoplasty, with the notable exception of the absence of the hyper-reflective donor-host interface.

Inhibiting corneal transplantation rejection via lymphatic vessel ligation in a novel murine model

The lymphatic system is a crucial contributor to allograft rejection after corneal transplantation. However, no surgical procedures for the central pathway where conjunctival lymphatic vessels converge have been investigated. Therefore, we aimed to establish a murine model of lymphatic vessel ligation and evaluate its inhibitory effect on corneal allograft rejection. A tracer was used to visualise lymphatic vessels, and complications were evaluated. A surgical technique was developed to block the lymphatic vessels. Corneas from C57BL/6 mice were transplanted into BALB/c mice divided into two groups—one with and one without lymphatic vessel ligation, to evaluate their effects on allograft rejection. Graft opacity scores were evaluated for 8 weeks, and immunohistochemistry was used to quantify angiogenesis and lymphangiogenesis. 20% trypan blue used as a tracer showed clear inflow with no complications. The two sutures and cyanoacrylate glue combination demonstrated a blocking effect after 25 days and was thus used for lymphatic ligation. Three and nine out of fourteen eyes showed rejection at 8 weeks post-surgery in the lymphatic vessel ligation and control groups, respectively. Furthermore, neovascularisation and lymphangiogenesis significantly decreased in the lymphatic vessel ligation group. Overall, we present a novel therapeutic strategy for corneal transplantation.

Integrated environmental and health economic assessments of novel xeno-keratografts addressing a growing public health crisis

Tissue scarcity poses global challenges for corneal transplantation and public health. Xeno-keratoplasty using animal-derived tissues offers a potential solution, but its environmental and economic implications remain unclear. This study evaluated two xeno-keratoplasty procedures at a single institution: (1) native corneas (Option 1) and (2) tissue-engineered corneal scaffolds derived from slaughterhouse waste (Option 2). Life cycle assessment (LCA) quantified environmental impacts across 18 midpoint indicators, while cost-effectiveness analysis (CEA) incorporated cost and environmental impact using two approaches. Option 1 exhibited significantly lower environmental impact than Option 2 across most indicators, primarily due to the energy and equipment demands of cell culture in Option 2. Both CEA approaches (carbon offset pricing and utility decrement) demonstrated cost-effectiveness dominance for Option 1. Xeno-keratoplasty using native corneas (Option 1) appears more environmentally and economically favorable than tissue-engineered scaffolds (Option 2) in the current analysis. Future studies could explore diverse xeno-keratoplasty techniques for optimizing sustainability.

Influence of surgeon learning on outcomes in new ophthalmic procedures: quantified nationwide evidence in endothelial corneal transplantation

AimsTo investigate the impact of surgeon learning on endothelial keratoplasty (EK) procedure outcomes.MethodsA prospective nationwide registry study of EK grafts in patients aged at least 21 years with Fuchs endothelial...

Treatment of equine keratomycosis, part 1: selection of appropriate therapy based on clinical presentation and diagnostic testing improves clinical outcomes.

To determine clinical outcome, treatment costs, and hospitalization duration in horses treated for keratomycosis and identify ophthalmic examination and diagnostic results associated with these outcomes. This was a retrospective study of 126 equine keratomycosis cases between 2004 and 2020 with fungal infection confirmed on cytology, culture, and/or histopathology and a minimum of 1-month follow-up. Details of the ophthalmic examination, diagnostic test results, and treatment and cost outcomes were recorded. Outcomes of interest were analyzed by treatment type. The relationship of patient and diagnostic test variables to the outcomes of interest was determined via logistic and linear regression models. Globe retention and positive visual outcome occurred in 82.5% and 78.9% of medically and 88.4% and 85.5% of surgically treated cases, respectively. While not statistically significant, there were more positive clinical outcomes with surgery; in recent years, the globe and vision were preserved in 94.7% of cases following penetrating keratoplasty. The choice to pursue surgery was related to lesion depth. Medical treatment was associated with statistically shorter hospitalization times and lower total and hospitalization invoices compared to all surgical treatments. Diagnosis of stromal abscess was associated with higher total invoice and longer hospitalization times compared to ulcerative keratomycosis, although clinical outcomes were similar. Overall positive clinical outcomes were achieved despite the severity of the disease in many cases, highlighting the need for appropriate treatment selection based on clinical presentation. Expanding knowledge of clinical decision-making, treatment options, and associated clinical and financial outcomes may further improve outcomes for equine keratomycosis patients.