This study will potentially include 5 cohorts with a minimum of 3 patients per cohort, with an optional cohort of up to 6 patients. This trial design uses a staggered patient enrollment with continuous data reviews to limit as much unforeseen risk as possible prior to enrolling each patient in each cohort or initiating another cohort. Only one eye (designated as the study or treated eye) will be dosed per patient. Each patient will be followed for 5 years after the subretinal injection of CPK850.