Stem cell therapy for retinal diseases

Background Due to an ageing population the incidence and prevalence of retinal diseases and visual disabilities will continue to grow. A great number of patients would principally be able to benefit from a stem cell-based therapy. Objectives To introduce readers to the terminology and current concepts associated with stem cell therapy in ocular research and to provide an overview of the current status of preclinical and clinical research. Materials and Methods We performed a systematic review of relevant entries on ocular stem cell therapy for retinal diseases in PubMed and ClinicalTrials.gov. Differences between various stem cell types are displayed systematically, followed by a discussion of preclinical studies. Translational aspects are highlighted leading to the first clinical trials, including surgical and ethical facets. Results In preclinical studies, photoreceptor cell precursors and retinal pigment epithelium (RPE) cells were differentiated and subretinally transplanted into animal models. Besides exclusion of a teratoma formation, some functional improvements were also observed. Intraocular transplantation of stem cell-derived RPE cells was the first successful clinical application of pluripotent stem cells in man. Conclusions Promising results of preclinical and clinical studies have identified important challenges and confirmed the potential of stem cell therapy for ophthalmology.