Table 1: A
summary of cell replacement therapies currently in development for retinal
repair, including the main challenges and clinical trial information (adapted
from http://clinicaltrials.gov)
Cell Therapy |
Main Challenges |
Clinical Trial Examples |
Embryonic stem cells (ESCs) |
> Obtaining safe, stable and effective cell sources > Finding a realistic up-scaling strategy > Chance of immunorejection |
> Advanced
Dry Macular Degeneration treatment (California, US) [52] > Age
related Macular Degeneration treatment (Israel) [53] > Stargardt
Macular Dystrophy treatment (US) [54] > Advanced
Dry Age related Macular Degeneration treatment (US) [55]
+ long term follow up study [56] > Advanced
Dry Age related Macular Degeneration treatment (Korea) [57] |
Induced pluripotent stem cells
(iPSCs) |
> Potential time + cost of autologous cell
therapy > May require gene correction before
autologous transplantation |
> Investigation of genetic retinal diseases
(Minnesota, US) [58] > Investigation of retinal degenerative
diseases (Maryland, US) [59] > iPSCs
derived from retinoblastoma patients (Tennessee, US) [60] > Age
related Macular Degeneration treatment (UK) [61] |
Mesenchymal stem cells
(MSCs) |
> Large scale differentiation of MSCs into
functional cells makes cell replacement therapy problematic |
> Stem cell ophthalmology treatment study
(Florida, US) [62] |
Adipose stem cells (ASCs) |
> Risk of transplanted cells migrating towards
non-targeted regions > Potential costs of autologous cell therapy |
> Glaucomatous
neurodegeneration treatment (Russia) [63] |
Retinal progenitor cells
(RPCs) |
> Ability to integrate
into retinal circuitry > Chance of
immunorejection |
> Retinitis
pigmentosa treatment (UK + US) [46,47] > Retinitis
pigmentosa treatment (California, US) [64] |
Retinal pigmented epithelium
(RPE) transplantation |
> High chance of immunorejection > Survival + function of transplanted RPE
difficult on aged and deteriorated Bruch's membrane |
> Acute Wet Macular Degeneration treatment
(London, UK) [65] > Age related Macular Degeneration treatment
(Austria) [66] |