Last week, the researcher team from Japan reported the first adverse event following a stem cell transplant for the treatment of wet AMD.

Refresh me on the trial.
In early 2017, a 60-year-old man in Japan became the first patient to receive stem cells donated by another person to treat his wet AMD. A total of five patients were included in the trial.

Why did they use donor stem cells instead of the patients own stem cells?
Because one downside to using a patients own stem cells is that these patients tend to be elderly and therefore may have genetic defects that could increase the risk of the procedure. However, using donor stem cells isn’t perfect either. They don’t offer an exact genetic match and it raises the prospect of immune rejection.

What was the adverse event?
The patient developed an epiretinal membrane with macular edema. They operated on him last week to remove the membrane.

Are they stopping the trial?
No. The authors state this case isn’t serious and it likely will not affect future clinical studies.