title: Stem cell therapy for retinal disease.
abstract: OBJECTIVE
  Stem cell therapy holds great promise for the treatment of retinal diseases. This review summarizes recent advances in stem cell biology, outlines ongoing clinical trials and details the obstacles that must be overcome for stem cell therapy to be a viable treatment for retinal disease.
  
  
  RESULTS
  Stem cells can now be directed to specific retinal cell fates with high yields and acceptable purity for clinical trials. New stem cell sources have been discovered including induced pluripotent stem cells that can be derived from adult tissues then differentiated into multiple retinal cell types. The initial results of clinical trials of subretinal transplantation of human embryonic stem cell-derived retinal pigment epithelium cells in patients with Stargardt's macular dystrophy and dry age-related macular degeneration showed preliminary safety and possible visual acuity benefits. A phase I trial of intravitreally injected autologous bone marrow-derived mononuclear cells for hereditary retinal dystrophy demonstrated no evidence of toxicity with possible visual acuity benefits but no structural or functional changes. Ongoing trials are examining the trophic effects of undifferentiated umbilical cells for the treatment of geographic atrophy in age-related macular degeneration.
  
  
  CONCLUSIONS
  Stem cell therapy is a promising treatment under active investigation in multiple retinal diseases. Ongoing clinical trials should yield further insights into the potential for stem cell-based retinal therapies.
authors.affiliation: Wills Eye Institute Retina Service, Mid Atlantic Retina, Philadelphia, Pennsylvania 19107, USA. michael.tibbetts@gmail.com
authors.forename: Michael D
authors.initials: MD
authors.lastname: Tibbetts
authors.forename: Michael A
authors.initials: MA
authors.lastname: Samuel
authors.forename: Tom S
authors.initials: TS
authors.lastname: Chang
authors.forename: Allen C
authors.initials: AC
authors.lastname: Ho
mesh_terms: D002986:Clinical Trials as Topic; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000637:transplantation; D012164:Retinal Diseases / Q000628:therapy*; D033581:Stem Cell Transplantation / Q000379:methods*