In the wet form of age-related macular degeneration, damage and dysfunction gives rise to a maladaptive growth of leaky blood vessels into the retina, destroying its cells, structure, and function. Researchers here report on an early stage clinical trial of a twofold approach to the problem, combining surgery to remove blood vessels with delivery of retinal cells derived from stem cells in order to replace damaged tissue. Efficacy has yet to be determined rigorously, but initial results are encouraging, at least for those patients in which the surgery was successful in achieving the goal of clearing out the unwanted blood vessels.
Wet age-related macular degeneration (AMD) in its early stages can be treated with drugs to reduce the formation of new blood vessels, but this treatment is inefficient in cases where blood vessel formation is already in its advanced stages. A new, alternative treatment for those patients may be surgical removal of the abnormal blood vessels followed by the transplantation of stem cell-derived retinal cells.
In their clinical study, involving 10 patients with wet AMD, researchers first developed a method for safely removing the newly formed blood vessels followed by the transplantation of stem cell-derived retinal cells to replace the patients' damaged or lost retinal cells. The retinal structure improved in those patients where blood vessel patches were completely removed during surgery, suggesting that the transplanted cells survived and repaired the damaged retina. Further, visual acuity remained stable or improved in those patients during the 12-months follow-up, with limited side effects. In contrast, patients where the blood vessel patches could only partially be removed experienced persistent bleeding and inflammation in the eye and an incomplete regeneration of the retina, and vision did not improve in those patients.
Researchers concluded that complete and safe removal of the blood vessel patches prevents inflammation and generates a milieu favorable for transplant survival and integration. Follow up studies with larger groups of patients are required to confirm the clinical efficacy and favorable safety profile of this type of treatment.
View the full article at FightAging
