New developments in retinal cell transplantation and the impact of stem cells

Abstract

Retinal cell transplantation, especially transplantation of retinal epithelium, could provide a method to cure age-related macular degeneration but major hurdles have hampered its advance, such as rejection and surgical technique. The possibility to use autologous fibroblasts from the potential transplant recipient to convert these fibroblasts into pluri-potential cells in culture and then to transform them into retinal epithelium, including checks on their appropriate gene expression offers the possibility of eliminating the hurdle of host graft rejection. A new surgical technique that sections the neural retina for 180° at the temporal ora serrata and folds it nasally to expose the macula and its degenerate epithelial layer can improve the delicate microsurgery. It eliminates jet stream trauma that produces a hole in the equatorial retina and the poor visibility of the epithelium seen through a detached, opaque neural retina. It allows the surgeon to use both hands in removing degenerate epithelium and replacing it with a patch of pristine epithelium. The neural retina can then be folded back to its original location and laser secured at the ora serrata. Transplantation of photoreceptors has greater hurdles, the major one being a guarantee of sufficient synaptic connectivity of transplanted cones to host cone bipolars.