Iris pigment epithelium transplantation

Background: Iris pigment epithelium (IPE) cells and retinal pigment epithelium (RPE) cells possess the same embryonic origin. It is also known that the pigmented epithelial cells in the eye have a high transdifferentiation potential. In this study we transplanted IPE cells into the subretinal space of albino Royal College of Surgeons (RCS) rats and evaluated their influence on the degeneration of the photoreceptors. Methods: IPE cells of Long Evans rats were isolated and pure cultures were obtained. The isolated cells were transplanted into the subretinal space of RCS rats. Light microscopic and morphometric analysis were carried out. Results: The IPE transplants survived in the subretinal space and attached themselves to the Bruch's membrane. The transplanted cells were able to delay the degeneration of the photoreceptors for up to 3 months. Conclusion: These results suggest that IPE cells could be successfully transplanted and survive in the subretinal space. In the transplanted eyes the photoreceptors were preserved for a period of 3 months. Further studies are needed to explore the capability of IPE cells to assume the main functions of RPE cells in the subretinal space and their potential in the therapy of selective degenerative diseases of the retina.