Corneal Transplantation

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...

Corneal endothelial dysfunction poses significant challenges in ophthalmology, leading to corneal edema and vision loss. Traditional treatments, including corneal transplantation, are limited by donor scarcity and potential complications. Nanoparticle-mediated cell delivery emerges as a promising approach for corneal endothelial regeneration, offering targeted and minimally invasive solutions. This comprehensive review provides insights into the role of nanoparticles in enhancing cell survival, integration, and therapeutic efficacy...

Smartphones are increasingly relevant resources in medical practice as they are ubiquitous and reasonably cheap. Among the advantages of using smartphones in medical practise, there is the possibility of obtaining reproducible photographic documentation of various conditions. This is particularly true in the ophthalmic field, where anterior segment color photography plays a significant role in the diagnosis and the management of ocular surface diseases. Here we propose an original design for an open-source smartphone accessory for taking and sharing high-definition photographs of the anterior segment...

BACKGROUND: Melting corneal ulcers are a serious condition that affects a great number of animals and people around the world and it is characterised by a progressive weakening of the tissue leading to possible severe ophthalmic complications, such as visual impairment or blindness. This disease is routinely treated with medical therapy and keratoplasty, and recently also with alternative regenerative therapies, such as cross-linking, amniotic membrane transplant, and laser. Plasma medicine is another recent example of regenerative treatment that showed promising results in reducing the microbial load of corneal tissue together with maintaining its cellular vitality...

PURPOSE: To assess the outcomes of deep anterior lamellar keratoplasty or penetrating keratoplasty at the scar and the edema stages. METHODS: Forty-five patients (45 eyes) with keratoconus scar stage (scar group, n=26; penetrating keratoplasty a subgroup, n=7; deep anterior lamellar keratoplasty b subgroup, n=19) and keratoconus edema stage (edema group, n=19; penetrating keratoplasty c subgroup, n=12; deep anterior lamellar keratoplasty d group, n=7) who received penetrating keratoplasty or deep anterior lamellar keratoplasty from 2000 to 2022 were retrospectively studied...

No abstract text is available yet for this article.

Corneal crosslinking (CXL) represents a paradigm shift in the management of corneal ectatic disorders. Before CXL was introduced, patients would need specialty contact lenses and possible corneal transplantation. CXL involves a biochemical reaction in which ultraviolet A light is used in conjunction with Riboflavin to form crosslinks in between corneal stromal collagen. This leads to strengthening and stabilizing of the collagen lamellae, resulting in mechanical stiffening of the cornea. Multiple protocols have been proposed including epithelium on versus off and varying light intensity and duration of treatment...

PURPOSE: To verify corneal biomechanical changes, poststromal augmentation using myopic small-incision lenticule extraction's (SMILEs) lenticules in advanced keratoconus (KCN) through Corvis ST (Oculus, Wetzlar, Germany). MATERIALS AND METHODS: A clinical trial enrolled 22 advanced KCN patients. We implanted lenticules exceeding 100 μ according to a nomogram and evaluated biomechanical factors through Corvis ST at 3-, 6-, and 24-month postimplantation. We examined parameters during the first applanation (A1), second applanation (A2), highest concavity (HC)/max concavity events, and Vinciguerra screening parameters, as recently established criteria derived from the ideal blend of diverse biomechanical and ocular factors and formulated through the application of logistic regression...

Deep anterior lamellar keratoplasty (DALK) has emerged as a transformative approach in managing corneal pathologies, notably keratoconus (KC), providing a viable alternative to penetrating keratoplasty (PK). This systematic review explores the intricacies of DALK, comparing its preoperative, intraoperative, and postoperative considerations with PK. Extensive literature searches revealed a wealth of data regarding DALK's advantages and challenges, with an emphasis on graft survival, visual outcomes, and complications...

OBJECTIVE: Our objective is to develop a novel keratoconus image classification system that leverages multiple pretrained models and a transformer architecture to achieve state-of-the-art performance in detecting keratoconus. METHODS AND ANALYSIS: Three pretrained models were used to extract features from the input images. These models have been trained on large datasets and have demonstrated strong performance in various computer vision tasks.The extracted features from the three pretrained models were fused using a feature fusion technique...

PURPOSE: To establish a national consensus on contraindications for corneal donation for transplantation in Switzerland. METHODS: Swisstransplant (SWT), the Swiss national foundation coordinating tissue and organ donations, convened a working group consisting of six national corneal surgeons and eye bankers and donation experts to create a contraindication list for corneal donation. The group reviewed available national and international guidelines and recommendations, while adhering to Swiss law and transplant regulations...

No abstract text is available yet for this article.

The activation of innate immunity following transplantation has been identified as a crucial factor in allograft inflammation and rejection. However, the role of cGAS/STING signaling-mediated innate immunity in the pathogenesis of allograft rejection remains unclear. Utilizing a well-established murine model of corneal transplantation, we demonstrated increased expression of cGAS and STING in rejected corneal allografts compared to syngeneic and normal corneas, along with significant activation of the cGAS/STING pathway, as evidenced by the enhanced phosphorylation of TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3)...

PURPOSE: To report the indications, surgical techniques, and outcomes of repeat keratoplasty and evaluate the risk factors for graft failure in the Chinese population. METHODS: The medical records of 216 patients (243 cases) who underwent at least two keratoplasties at a leading eye hospital in southern China between 2011 and 2020 were retrospectively reviewed. Indications and surgical procedures for repeat corneal transplantation were analyzed. Kaplan-Meier survival analysis was used to determine the graft survival rate after repeat keratoplasty...

Acanthamoeba spp. emerged as a clinically important pathogen related to amoebic keratitis. It is among the main causes of corneal transplantation and vision loss in ophthalmology. The treatment protocols have a low cure rate, high toxicity, and need for drug combination. Transition metal compounds have shown promising antiprotozoal effects. This study evaluates the amoebicidal activity of copper(II) coordination compounds in combination with chlorhexidine and the cytotoxicity to topical ocular application. These copper(II) coordination compounds were screened against Acanthamoeba castellanii trophozoites (ATCC 50492)...

Cornea-related injuries are the most common cause of blindness worldwide. Transplantation remains the primary approach for addressing corneal blindness, though the demand for donor corneas outmatches the supply by millions. Tissue adhesives employed to seal corneal wounds have shown inefficient healing and incomplete vision restoration. We have developed a biodegradable hydrogel - Kuragel, with the ability to promote corneal regeneration. Functionalized gelatin and hyaluronic acid form photo-crosslinkable hydrogel with transparency and compressive modulus similar to healthy human cornea...

Facial burns involving the periorbital region may lead to cicatricial ectropion and lagophthalmos, causing severe exposure keratopathy and eventually blindness if uncorrected. In these patients, it is critical to provide aesthetic and functional surgical correction to protect the ocular surface from chronic desiccation in addition to visual rehabilitation. Conventional methods may not be sufficient to provide visual rehabilitation in complex cases. Scleral lenses can be a multipurpose alternative for these patients...

BACKGROUND: Immunological rejection is the most common reason for corneal transplantation failure. The importance of T cells in corneal allograft rejection is well demonstrated. Recent studies highlight that pigment epithelium-derived factor (PEDF) plays an immunoregulatory role in ocular diseases by enhancing the suppressive phenotype of regulatory T cells besides its other functions in neurotrophy and antiangiogenesis. METHODS: The effects of PEDF on immune rejection were examined in rat models of corneal transplantation using slit-lamp microscope observation, immunohistochemistry, flow cytometry, and Western blot...

PURPOSE: An increase in fungal and particularly filamentous keratitis has been observed in many geographic areas, mostly in contact lens wearers. This study seeks to characterize long-term trends in fungal keratitis in a continental climate area to provide guidance for diagnosis and treatment. DESIGN: Retrospective multicentric case series. METHODS: Cases of microbiology-confirmed fungal keratitis from 2003 to 2022 presenting to tertiary care centers across Canada were included...

BACKGROUND: The aim of this study was to assess the impact of the ratio between the graft and host corneal size (RGH) on postoperative complications, such as immune reactions, re-bubbling rate and endothelial cell loss (ECL) after Descemet membrane endothelial keratoplasty (DMEK). PATIENTS AND METHODS: Retrospectively, 457 patient eyes were included which had undergone surgery between 2016 and 2019 in the Department of Ophthalmology, Saarland University Medical Center in Homburg/Saar using DMEK or triple DMEK, diagnosed as Fuchs' endothelial dystrophy (n = 431), pseudophakic bullous keratopathy (n = 9) and others (n = 17)...