title: Transplantation of autologous iris pigment epithelium to the subretinal space in rabbits.
abstract: BACKGROUND
  Transplantation of autologous iris pigment epithelium (IPE) into the subretinal space has been suggested as one approach for the treatment of age-related macular degeneration. Autologous rabbit IPE cells were transplanted to the subretinal space to define the technique of transplantation and examine the survival of the transplanted cells.
  
  
  METHODS
  Autologous IPE cells were harvested by iridectomy and transplanted directly to the subretinal space of the fellow eye in 25 rabbits, using the parsplana approach. Animals were killed over a period of 5 months, and the retinas were examined morphologically by light and electron microscopy.
  
  
  RESULTS
  Autologous IPE cells survived and formed a polarized monolayer above the retinal pigment epithelium in the subretinal space, with apical microvilli adjacent to photoreceptors. Fragments of phagocytosed photoreceptor rod outer segments were observed in phagosomes in the cytoplasm of IPE cells. Adjacent rod outer segments remained healthy throughout the experimental period. No signs of a cell-mediated immunologic response were observed.
  
  
  CONCLUSIONS
  Our results show that in rabbits, autologous IPE cells transplanted to the subretinal space survive and do not adversely affect the photoreceptors. These results suggest that in humans, IPE cells might provide a substitute for retinal pigment epithelium cells as autologous transplants for the treatment of age-related macular degeneration.
authors.affiliation: Department of Vitreoretinal Surgery, University of Cologne, Germany. ThumannGa@aol.com
authors.forename: G
authors.initials: G
authors.lastname: Thumann
authors.forename: K U
authors.initials: KU
authors.lastname: Bartz-Schmidt
authors.forename: H
authors.initials: H
authors.lastname: El Bakri
authors.forename: U
authors.initials: U
authors.lastname: Schraermeyer
authors.forename: C
authors.initials: C
authors.lastname: Spee
authors.forename: J Z
authors.initials: JZ
authors.lastname: Cui
authors.forename: D R
authors.initials: DR
authors.lastname: Hinton
authors.forename: S J
authors.initials: SJ
authors.lastname: Ryan
authors.forename: K
authors.initials: K
authors.lastname: Heimann
mesh_terms: D000818:Animals; D005123:Eye / Q000166:cytology; D005260:Female; D007498:Iris; D007633:Keratins / Q000032:analysis; D008854:Microscopy, Electron; D010857:Pigment Epithelium of Eye / Q000737:chemistry / Q000637:transplantation* / Q000648:ultrastructure; D011817:Rabbits; D012160:Retina; D014182:Transplantation, Autologous / Q000473:pathology; D016042:Transplantation, Heterotopic
chemical_list: D007633:Keratins