RGX-314 Gene Therapy is a new treatment for diabetic retinopathy (DR), a condition caused by diabetes that can damage the eyes and cause vision loss. This treatment is aimed at being a one-time solution, which could be more convenient than current treatments that require frequent eye injections. In this study, researchers want to test if RGX-314 is safe and effective for people with DR who do not have a specific eye condition called center-involved diabetic macular edema (CI-DME). About 100 people will join the study and be placed into different groups to receive different doses of RGX-314 or to be observed without treatment. Participants will be closely monitored for safety and how well the treatment works. The study is looking for people aged 25 to 89 with certain types of diabetic retinopathy, and who haven't needed certain treatments recently. Women who can have children are not eligible to join.

• The study involves a one-time gene therapy treatment.
• Participants will be monitored for safety and effectiveness of the treatment.
• Eligible participants will be aged 25-89 and have specific eye conditions.