Regenerating the Retina

Retinal progenitor cell transplantation offers a new approach to repairing damaged photoreceptors

By Irv Arons

At a Glance

  • Retinal progenitor cells (RPCs) can replicate many times and mature into many of the major retinal cell types
  • Clinical trials of RPCs for the repair of degenerated retinas are already underway
  • The results so far are promising: most patients exhibit improvement in their vision, with no safety issues reported to date
  • Other technologies – stem cell and gene therapy, electronic retinal implants and “retinal rejuvenation” – are also being investigated

Retinal degenerative diseases (RDDs) are a significant source of visual disability across the globe, with age-related macular degeneration (AMD) being the most common. A great number of RDDs have a genetic origin – like choroideremia, retinitis pigmentosa (RP), Leber congenital amaurosis and Stargardt disease, but irrespective of the cause, the treatment options available today are pretty limited. Wet AMD might be treatable for a period with intravitreal VEGF inhibitors, but for many patients, this only postpones the inevitable. The loss of photoreceptor cells – as seen in the later stages of RP, dry AMD geographic atrophy, and the late stages of Stargardt disease – results in permanent visual loss. There’s no approved therapy available  yet that can slow or reverse the pathology. One potential way of doing this – placing retinal progenitor cells (RPCs) in the retina to replace the damaged cell types – is a therapeutic avenue that’s generating a lot of attention.