Use of Embryonic Stem Cells to Treat Severe Eye Diseases

The use of stem cells in regenerative medicine has major therapeutic potential. Recent clinical trials using cells derived from human stem cells are showing encouraging results, although these should be assessed with the necessary caution.

Some media have reported the results of these trials without due care, perhaps creating expectations that do not match the reality of the facts. This paper describes some of the recent advances in the use of human stem cells, particularly those made in the area of ophthalmology, and more specifically, in Stargardt's disease and age-related macular degeneration (AMD). We also present promising studies with induced pluripotent stem cells (iPS), aimed at obtaining retinal pigmented epithelium and light-sensitive retinal rods in the aforementioned ocular diseases, with encouraging preclinical and clinical results.

From a medical point of view, we must not forget that the transplanted retinal epithelium cells may cause tumours, since they have been obtained from Embryonic Stem cells, and may trigger immune rejection problems since they are heterologous. These considerations attest to the ethical uncertainty of the results of these clinical trials, but above all, it must be stressed that whenever Embryonic Stem cells are used, a human embryo must be destroyed to obtain them, which of course has objective ethical difficulties.