Long-Term Ultrastructural Outcomes of Autologous Transplantation of Retinal Pigment Epithelium—Partial Thickness Choroid (RPE-PTC) Sheet in Rabbits

Abstract

Background: To observe the ultrastructural outcomes of autologous transplantation of retinal pigment epithelium-partial-thickness choroidal (RPE-PTC) sheets in rabbits after 6 months. Methods: Eighteen pigmented rabbits were used in this study. Among them, nine rabbits were used for autologous transplantation of RPE-PTC sheets. Tissue sections were observed under a transmission electron microscope for one, three, and six months after transplantation, respectively. Results: One, three, and six months after the autologous transplantation of RPE-PTC sheets, the inner and outer segments of photoreceptor cells were arranged regularly, and the connection between the inner and outer segments was normal. The inner structure of the RPE cells and tight junctions among them remained normal. Phagocytosis of outer segment of photoreceptor cells could also be observed in RPE cells. The structure of the Bruch’s membrane appeared loose, rather than being dense as normal, and it was undulated after one and three months, while it became dense after six months. The graft and the bed were healed well, the boundary was unclear, and the graft was vascularized after one, three, and six months, respectively. Conclusions: Our findings revealed that the RPE-PTC sheets could quickly rebuild blood vessels, thereby maintaining the normal physiological functions of RPE cells, as well as the survival and functional status of photoreceptor cells for a long-time.

Keywords

• age-related macular degeneration
• autologous transplantation
• retinal pigment epithelium (rpe)
• ultrastructure
• transmission electron microscopy