View clinical trials related to Limbal Stem Cell Deficiency.
Filter by:Objectives The transparent surface of the eye, called the cornea, plays a crucial role in transmitting light to the retina and in protecting the eye. On its external surface, the cornea is composed of a constantly renewing multistratified epithelium. This mechanism is fueled by stem cells located in the limbus (the transition zone between the cornea and the sclera). Limbal Stem Cell Deficiency (LSCD) is characterized by a decrease or cessation of epithelial renewal and neovascularization of the cornea. Consequently, the cornea loses its integrity and transparency. This visually impairing condition is currently in a therapeutic impasse as only autologous limbal or allogeneic corneal grafts are viable options, but they pose significant risks to patients. Studies have shown that the oral cavity contains stem cells that can be isolated, cultured, and transdifferentiated into limbal stem cells (LSCs). However, to date, these studies are limited, and no protocol has been validated. In this study, the advantage of the accessibility of the oral cavity is used to develop a protocol for differentiating cells from the oral mucosa into limbal stem cells (LSCs) for use in a future clinical trial with patients. Methodology This prospective monocentric study will be conducted on patients from the ophthalmology department of the Montpellier University Hospital who have an indication for conjunctival reconstruction. After obtaining consent from the patients, cells from the oral wall will be sent to the tissue bank of the Montpellier University Hospital, where they will be cultured. Finally, the transdifferentiation steps will be analyzed by the "Eye" research team at the Institute of Neuroscience in Montpellier, which is collaborating on the project. The investigators have established objective factors to assess the success of the developed protocol based on the literature : (i) > 3% of stem cells in primary cultures, (ii) <10% aborted colonies, (iii) Expression of LSC markers (Pax6, Krt14, p63).
In order to develop innovative biomarkers for the diagnosis of two ocular surface pathologies, Dry Syndrome (DS) and Limbic Stem Cell Deficiency (LSCD), human cells from the ocular surface will be collected in order to test these biomarkers ex vivo.
Limbal Stem Cell Deficiency (LSCD) is a blinding disease that accounts for an estimated 15-20% of corneal blindness worldwide. Current treatments are limited. Traditional corneal transplantation with penetrating keratoplasty (PKP) is ineffective in treating these patients. Without a healthy population of limbal stem cells (LSC) to regenerate the corneal epithelium, standard corneal transplants will not re-epithelialize and will rapidly scar over or melt. The limbal niche is the microenvironment surrounding the LSCs that is critical for maintaining their survival and proliferative potential under physiologic conditions. Extracellular signals from the microenvironment are critical to the normal function and maintenance of pluripotent stem cells. Identifying an effective niche replacement is thus an important focus of limbal stem cell research and critical for advancing treatments for LSCD. Descemet's membrane (DM), an acellular, naturally occurring, basement membrane found on the posterior surface of the cornea, is a promising niche replacement. DM is routinely isolated and transplanted intraocularly with associated donor corneal endothelium for treatment of diseases like Fuchs' dystrophy and corneal bullous keratopathy that specifically affect DM and corneal endothelium. However, its application on the ocular surface has not been explored. DM is optically clear and highly resistant to collagenase digestion. This makes it very attractive as a long-term corneal on-lay and niche replacement on the surface of the eye. The anterior fetal banded layer of DM shares key compositional similarities with limbal basement membrane, which is a major component of the limbal niche. These similarities include limbus-specific extracellular matrix proteins such as collagen IV that is restricted to the α1, α2 subtypes, vitronectin, and BM40/SPARC. Of these, vitronectin and BM40/SPARC are known to promote proliferation of LSCs and induced pluripotent stem cells (iPSC) in culture. Because of this, DM is a promising biological membrane for establishing a niche-like substrate on the corneal surface in patients with LSCD. The purpose of this pilot study is to investigate the clinical efficacy of using DM as a corneal on-lay to promote corneal re-epithelialization in partial LSCD.
Integrity of the corneal epithelium is the function of intact limbal stem cells. The reduction in the population of LSCs and their dysfunction result in abnormal corneal epithelialization and invasion of the corneal surface by the conjunctival epithelium with or without corneal neovascularization that is, limbal stem cell deficiency (LSCD). Different techniques have been developed to treat cases of limbal stem cell deficiency due to traumatic or congenital cases. Recent innovations developed to predict the early stages of stem cell deficiency. One of these methods is measurement of the central epithelial thickness as it was found that limbal stem cell deficiency causes reduction of the central epithelial thickness. The aim of this study is to study changes in the corneal epithelial thickness at different quadrants of the cornea to observe the exact time of epithelial stability following stem cell transplantation.
Ocular surface photography is significantly limited in standardization and reproducibility. This reduces its applicability for clinical monitoring of acute or chronic disease. The innovative lens and illumination design of the CDL system aims to yield standardized high resolution photographs of the cornea and conjunctiva as required for clinical documentation, posing a significant clinical benefit of health care providers in the field of ophthalmology. Primary objectives: The primary objective of this study is to test the safety and feasibility of the CDL imaging system in a clinical routine setting. This will include the comparison of subjective contrast sensitivity testing post imaging, and the measurement of examination duration per imaging session, and the comparison of image lightness in mesopic versus photopic imaging. Secondary objectives: The secondary objective of this study is to compare the image quality of the device and repeatability of lateral resolution, dynamic range, hue, saturation, lightness, and image position between colour photographs from a state-of the art slit lamp camera and the CDL system. This is a monocentric, prospective, observational study. Patients with ocular surface disease of variable aetiology routinely assigned to ocular surface photography, following informed consent, will be imaged using state-of-the-art colour photography and the CDL imaging system. Pictures of each patient will be taken under several standardized conditions with both methods, subsequently analysed and compared by a Medical Image Processing Specialist.
Earlier approaches for cornea reepithelization in patients with bilateral LSCD included allogeneic corneal limbus grafting from postmortem donor or livingrelated relatives with concomitant systemic immunosuppression (Cheung and Holland, 2017) and cultivated oral mucosal epithelial transplantation (COMET) (Nishida et al., 2004). The novel surgical technique for corneal re-epithelization were described by Liu et al. (2011) and Choe et al. (2019). In both clinical studies, the autologous labial mucosal epithelium graft was transplanted as a surrogate corneal limbus for purpose of treatment the LSCD. Authors reported positive outcomes in terms of anatomical success and corneal status improvement. The purpose of the study is to evaluate the feasibility of the novel surgical intervention in clinical use.
This study aims to prospectively evaluate the therapeutic effects of autologous simple limbal epithelial transplantation for patients with limbal stem cell deficiency. The change of visual acuity, quality of life and so on will be monitored before and after surgery.
To investigate the effect of allogeneic SLET and re-epithelialization after allogeneic SLET.
This phase I study will collect preliminary information on the activity and safety of cLSC. We will investigate the ability to manufacture and transplant cLSC onto the cornea successfully at the time of surgery (feasibility), and have cLSC begin to populate the ocular surface (efficacy) without serious adverse events (safety).
Earlier protocol for cultivated oral mucosal epithelial transplantation (COMET) requires trypsin/EDTA to isolate epithelial cells from tissue, and uses murine 3T3 cells as feeder cells, which results in biosafety concern. This study uses collagenase instead of trypsin/EDTA to isolate epithelial cells, and does not use 3T3 cells co-culture, so as to make an animal ingredient-free cell culture product. The purpose of the study is to evaluate the feasibility of the new protocol of COMET in clinical use.