Stem cell therapy in retinal disease.Handb Clin Neurol 2026; 218:365-385.HC
Stem cell therapy presents a new solution to cure degenerative diseases of the retina, which normally have limited ability to regenerate after injury. Stem cells are cells capable of self-renewal and differentiation into more specialized cells, and can be derived from both embryonic and adult sources. This definition encompasses a heterogeneous group of cells possessing varied potency and characteristics. Current attempts in applying stem cell technology to the retina have primarily focused on regenerating the retinal pigment epithelium (RPE) and light-sensing photoreceptor cells. They have not only shown the ability to prevent the death of host photoreceptors, but they can also differentiate into all major retinal cell types to replace lost cells. In vivo experiments, primarily performed in mice, have found that stem cell-derived RPE cells, photoreceptors, and their precursors can survive long-term in animal models without tumorigenicity or immune rejection. Following transplantation, these cells were able to integrate and mature in vivo, forming synapse-like structures with host retinal cells. Furthermore, transplants in mice were able to rescue visual function at a cellular and behavioral level. These promising preclinical results have led to clinical trials testing cell therapy in numerous diseases, including Stargardt macular dystrophy, age-related macular degeneration, retinitis pigmentosa, and central retinal vein occlusion. These trials have demonstrated the safety of cell therapy and have improved visual function in some patients. Scientific advances in the culturing of retinal organoids and the understanding of cell redifferentiation are informing the development of better stem cell therapies, which hold great potential for restoring vision to patients with retinal dystrophies.
