Restoring vision in AMD may be a possibility with stem cell transplantation.
Autologous versus allogeneic cells
There are also pro and cons associated with the use of types of cells used, i.e., autologous and allogeneic cells. The former has a reduced chance of an autoimmune response, but at the same time it is more expensive, mutations and copy number changes can be introduced during the reprogramming process, and the efficiency varies during differentiation because of the “memory” of the cell origins.
Allogeneic cells are “off the shelf” and cost less, but patients may have a greater need for immunosuppressive therapy.
The studies of embryonic stem cell injection into the eye date back to 2012 when The Lancet (doi: https://doi.org/10.1016/S0140-6736(12)60028-2) published the first results from 18 patients, half with Stargardt’s disease and half with dry AMD.
Of the seven patients followed for 1 year, the VAs ranged from 20/200 to hand motions. Three patients with AMD had a VA increase of 15 letters, one 13 letters, and three remained stable. In the Stargardt’s group, at 1 year, three had at least 15-letter improvements, three were stable, and one a decrease of more than 10 letters. The complications included a case of endophthalmitis and growth of RPE graft-derived epiretinal membranes. While the surgery generally appeared safe, adverse events occurred and there were no high-resolution imaging technologies available or any specific label for the transplanted cells.
A 2017 study of induced pluripotent stem cells published in the New England Journal of Medicine (2017;376:1038-1046) included two patients with advanced wet AMD. In one patient, the reprogramming induced oncogenic mutations. In a study published in Ophthalmology (2018;125:1765–1775) that included 12 patients with Stargardt’s disease, microperimetry showed no benefit of the treatment at 12 months in all patients and also found evidence of toxicity. Hyperpigmentation was seen, which suggested cell grafting; however, the hyperpigmentation also may be evidence of dead cells.
Rajesh Rao, MD
Dr. Rao has no financial interest in any aspect of this report.