الفهرس 
RetinITIS pigmentosaOnly 14 pages are availabe for public view
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Abstract
Summary
Retinitis pigmentosa constitutes a major cause of irreversible blindness in the world. It can cause debilitating progressive visual impairment at a young age, for which no cure is currently available. Stem cell-based therapies offer hope for these patients. Various sources of stem cells are currently being investigated, with the first clinical trials to investigate the safety and tolerability of human embryonic stem cell-derived retinal pigment epithelium cells having recently commenced. Whilst neuroprotective strategies may be beneficial for the treatment in the early stages of disease, stem cell transplantation could offer additional therapeutic strategies for patients in advanced stages, in which retinal neurons have been irreversibly damaged.
Recent studies have demonstrated that stem cells, due to their pluri- or multipotency and with their progeny, capable to differentiate into various different neural cell types. In addition, stem cells have the capacity to self renewal, giving them the potential to generate sufficient numbers of cells for transplantation Current research focuses on the identification and differentiation of suitable stem cells in vitro, their transplantation and replacement of functional retinal neurons and their supportive RPE cells. Various types of stem cells have been studied for use in retinal transplantation therapies; most prominently human embryonic stem cells (hESC), induced pluripotent stem (iPS) cells and adult stem cells such as human Müller stem cells (hMSC).
The first clinical trials investigating the transplantation of hESC derived RPE have been recently approved by the European and American regulatory authorities and began recruitment in 2011. And are designed to test the safety and tolerability of grafted hESC-derived RPE cells. Although primarily designed as safety studies, functional outcome measures such as best corrected visual acuity, multifocal ERG(most important), reading speed as well as structural evidence from optical coherence tomography (OCT) and auto fluorescence imaging are being recorded and are used both for clinical purposes as well as for preclinical and clinical trials. Nevertheless, the reporting interval of these clinical trials tests was short and any functional improvement may be more pronounced when the studies are scheduled to end after years. Conversely, stem cell therapies for the treatment of retinal degenerations are not yet available and are currently being investigated in preclinical or early clinical trials. These studies aim at assessing the possibility to prevent, or delay the onset of, or even to regenerate and repair established retinal damage through the transplantation of stem cell-derived neurons or retinal pigment epithelium