While the results of the clinical trials have been extensively reported since the. Amniotic membrane transplantation first used by kim and tseng in1995 for corneal surface reconstruction in a rabbit model of limbal stem cell deficiency have also been used. Objective to report phenotypic analysis of epithelia before and following cultivated limbal epithelial transplantation clet for eyes with limbal stem cell deficiency. Limbal cells harvested by a 1mm 2 biopsy specimen from live donor or.
These limbal stem cells become lost or deficient in the blinding disease of limbal stem cell deficiency. These cells are known as corneal epithelial scs or limbal stem ce lls. Loss or damage to the limbal stem cell pool can lead to limbal stem cell deficiency lscd, where homeostatic maintenance of the corneal epithelium is compromised, leading to ingrowth of the conjunctiva. Limbal stem cells lscs transplantation is an effective surgical treatment to address limbal stem cells deficiency lscd resulting from stevens johnsons syndrome or corneal chemical burn. Aim to report the outcome of a series of patients with stem cell deficiency who underwent allolimbal transplantation and to describe a technique for this procedure. Regenerating eye tissues to preserve and restore vision. Conjunctival limbal autograft clau, which involves. Lescs share common features with other adult somatic stem cells including small.
Primary simple limbal epithelial transplantation along. Pdf regeneration of the corneal surface after an epithelial insult involves division, migration, and maturation of a specialized group of stem cells. Limbal stem cell transplantation health quality ontario. Techniques involving cell therapy represent a major advance in the treatment of ocular surface diseases. The clet technique depends on the culture of limbal biopsies to produce limbal cell sheets prior to transplantation. The limbus is composed of radial fibrovascular ridges the palisades of vogt that form a niche for corneal epithelial stem cells figure 1. In summary, limbal stem cell transplantation improves both vision and qualityoflife in patients with ocular surface disorders associated with lscd, and overall, the use of autologous tissue offers the best results. Hyaluronan ha, also termed hyaluronic acid or hyaluronate, is a major component of the extracellular matrix. Autologous limbal transplantation in patients with. Cornea epithelium is subject to constant trauma and shedding of the surface epithelium, and replenishment is from epithelial cells beneath and.
These cells have the capacity to keep on dividing throughout a persons lifetime, replenishing cells that are being sloughed o. Vision may improve, but many times, a secondary keratoplasty is needed to restore corneal clarity and its success is dependent on the presence of limbal stem cells. The border between the cornea and the white part of the eye is known as the limbus. Corneal diseases and blindness can result from deficiency in limbal stem cells, and autologous transplantation is often the only therapeutic option. Assessment of surgical outcomes of limbal transplantation.
Introduction the human ocular surface spans from the conjunct iva to the cornea and plays a critical role. Limbal stem cell transplantation is a surgical treatment to address lscd and restore a corneal epithelial phenotype. Corneal graft with amniotic membrane transplantation or limbal stem cell transplantation. The concept of limbal stem cell transplantation was based initially on the conjecture that it was the limbal epithelium that contained the stemcell population for corneal epithelial cellular proliferation and. This was because the transplanted donor epithelium consisted of transient amplifying cells with limited proliferative potential and lacked corneal epithelial stem. Cultured limbal epithelial transplantation clet is the most commonly used ex vivo method for limbal stem cell transplantation. It can be advantageous to produce lec in centralized labs and thereafter ship. Phenotypic study after cultivated limbal epithelial. Limbal stem cell damage after chemical injury, autoimmune disorders or iatrogenic trauma leads to corneal conjunctivalisation with new vessel formation, epithelium instability and visual. The limbal stem cells were obtained by enzymatic extraction from a small biopsy and cultured on a. Pdf on feb 24, 2012, kishore reddy katikireddy and others published limbal stem cell transplantation and corneal neovascularization find, read and cite. To describe the utility of simple limbal epithelial transplantation slet along with tumor excision in the management of extensive ocular surface squamous neoplasia ossn to avoid limbal. Limbal stem cell deficiency lscd is a clinical condition characterized by damage of cornea limbal stem cells, which results in an impairment of corneal epithelium turnover and in an invasion of the cornea by. Standardized limbal epithelial stem cell graft generation.
Deficits of limbal stem cells leads to a loss of limbal niche homeostasis and corneal epithelium, leading to corneal neovascularization, loss of cornea transparency and finally loss of vision. Clinical and laboratory evidence indicates that corneal stem cells are located at the limbus. Patients with bilateral limbal stem cell deficiency or severe unilateral limbal stem cell deficiency, who are not candidates for autologous transplantation alone, require allograft tissue to restore their limbal. Although corneal transplantation is a standard treatment for serious cornea diseases, many patients are not able to recover from blindness due to limbal stem cell deficiency lscd. Preclinical cellbased therapy for limbal stem cell. The limbal stem cells are few in number and can be damaged by a number of. Emerging techniques are investigating the potential of reprogramming cells from various sources obtained through other minimally invasive techniques.
Limbal compromise results in ocular surface abnormalities characterized by chronic epithelial defects, stromal inflammation, and corneal conjunctivalization and neovascularization. Future studies aim at improving cellular expansion and finding different sources of stem cells. Hyaluronanbased hydrogel scaffolds for limbal stem cell. Ula 1,2 1schepens eye research institute 2massachusetts eye and ear infirmary, harvard medical sch ool usa 1.
Limbal epithelial stem cells of the cornea stembook. The culture and transplantation of human limbal stem cells. Limbal stem cell transplantation and corneal neovascularization 445 renewal and provide a barrier between conjunctival and corneal epithelia. Limbal stem cell deficiency can be treated with transplantation of cultured human limbal epithelial cells lec. Limbal stem cell transplantation fernandes m, sangwan vs, rao. Effect of transportation on cultured limbal epithelial. In summary, limbal stem cell transplantation improves both vision and qualityoflife in patients with ocular surface disorders associated with lscd, and overall, the use of autologous tissue. Loss or damage to the limbal stem cell pool can lead to limbal stem cell deficiency. Allolimbal transplantation in patients with limbal stem. Limbal stem cell therapy, specifically ex vivo expansion of limbal epithelial cells and transplantation of limbal epithelial explants, is a relatively new technique and treatment option for limbal stem cell.
Request pdf limbal stem cell transplantation the past two decades have witnessed remarkable progress in limbal stem cell transplantation. At the corneoscleral junction in an area known as the limbus, there is a population of limbal epithelial stem cells lescs. Limbal transplantation in the management of chronic. Differentiation related expression of a major 64k corneal keratin in vivo and in culture suggests limbal location of corneal epithelial stem cells. Cultivated limbal stem cells are harvested and grown on a substrate to be.
Limbal stem cell transplantation ontario health technology assessment series 2008. All functional or anatomical conditions that damage limbal stem cells result in an impairment of corneal epithelial integrity and wound healing and cause a clinical entity named limbal. This nonsulfated glycosaminoglycan plays a key role in cell proliferation, growth, survival. Limbal stem cell deficiency lscd is a clinical condition characterized by damage of cornea limbal stem cells, which results in an impairment of corneal epithelium turnover and in an invasion of the cornea by the conjunctival epithelium. Based on the source of cells, limbal transplant can be autologous or allogenic. Recent regulatory approval of this technique in the eu represents the. To prevent corneal conjunctivalization, it is mandatory to replace a well functioning limbus by means of transplantation of limbal stem cells.
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