View clinical trials related to Limbal Stem Cell Deficiency.
Filter by: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.
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.
The purpose of the study is to explore whether femtosecond laser-assisted corneal epithelial autograft is more effective than limbal conjunctival autograft for ocular surface reconstruction in patients with limbal stem cell deficiency (LSCD).
This project aims to conduct a multicentre human clinical trial to effectively diagnose and treat limbal stem cell deficiency (LSCD) which can be caused by a number of different disease processes, all of which have a common denominator, i.e. a loss of the normal functioning epithelial stem cells of the cornea. A number of different diseases such as aniridia, steven johnson's syndrome, ocular cicatricial pemphigoid, bacterial keratitis, or chemical and thermal injuries to the cornea can lead to gradual loss of its functioning epithelial stem cells. This leads to vascularization of the cornea with surrounding conjunctival epithelium growing over it resulting in its scarring and opacification. These corneas, since vascular, no longer retain their immune privilege and prove extremely challenging to the ophthalmic surgeon. Grafting donor corneas which in normal circumstances (non vascular corneas) would give excellent results, exhibit high rates of rejection. This can be very frustrating for both the patient as well as the surgeon. Since there are a number of different contributing disease pathologies, our estimate is that there are approximately 100 patients per year in Belgium that suffer from some degree of LSCD. These patients are very often not correctly diagnosed since this is a relatively new disease first described in 1990 after the discovery of limbal epithelial stem cells in 1989. The low rates of diagnosis could potentially be increased by in vivo confocal scanning microscopy as a non invasive screening test to detect early signs of LSCD and therefore offer conservative treatment options. In the cases where total limbal stem cell deficiency has already developed, conventional corneal grafting is not suitable due to the high vascularity of the host bed. In this situation we propose transplanting standardized limbal epithelial stem cell grafts generated from the patient's own ocular stem cells (from the good eye, where available) or from HLA matched donors. Tiny 1 by 2mm superficial limbal (peripheral cornea) biopsy can be taken and the epithelial stem cells expanded in the laboratory on a biological substrate, until there is a graft measuring >8mm in diameter generated in 2 a week period. This can then be transplanted onto the diseased eye after removal of scar tissue using a novel surgical technique we have developed.
The study " Autologous cultured corneal epithelium (CECA) for the treatment of corneal lesions associated with limbal stem cell deficiency" is the first clinical trial of this product manufactured at the LOEX laboratory. The culture of corneal epithelium strives to produce a reconstructed tissue with the therapeutical aim of treatment of limbal stem cell deficiency. The study is a phase I/phase II study with the goal to evaluate safety and efficacy of the CECA graft for the treatment of human patients suffering from limbal stem cell deficiency. The trial is open to all genders. The inclusion of 5 minors is planned.