During the dose escalation stage participants will be treated in each of the 3 dose cohorts (low cells/dose; medium cells/dose; high cells/dose). Doses will be administered to the study eye via a subretinal injection. Four weeks after the last participant in each dose cohort is treated, the independent Data Safety Monitoring Board (DSMB) will review data and images. Depending on the safety data there will be a recommendation to proceed to the next higher dose; stop dose escalation; investigate a lower dose or repeat a dose level.