A 2-part Study Consisting of a Multiple Ascending Dose Safety Study in Participants With Macular Edema Following Branch Retinal Vein Occlusion and a Dose-finding Safety and Preliminary Efficacy Study in Participants With Either Diabetic Macular Edema or Neovascular Age-related Macular Degeneration

General Key Inclusion Criteria * Written informed consent before the first study-related activity * Be male or female ≥ 18 years of age * If female, have a negative serum pregnancy test at Screening and further negative urine tests immediately before each dose of study medication if the participant is a female of childbearing potential. General Key Exclusion Criteria * Be pregnant or breastfeeding * Have a history of cataract surgery and/or minimally invasive glaucoma surgery in the study eye within 90 days of Screening * Have uncontrolled blood pressure, defined as systolic ≥180 mmHg and/or diastolic ≥100 mmHg while a participant is at rest. * Have had Yttrium-Aluminum Garnet laser capsulotomy in the study eye within 90 days of Screening * Have had Pan-retinal Photocoagulation or focal thermal laser photocoagulation in the study eye * Have tractional retinal detachment in the study eye * Have uncontrolled glaucoma (defined as IOP ≥ 25 mmHg despite treatment with antiglaucoma medication) in the study eye BRVO-specific Inclusion Criteria Participants must: * Be diagnosed with BRVO in the study eye * Have a ETDRS BCVA letter score between ≤ 70 and ≥ 35 (20/40 to 20/200 Snellen equivalent) in the study eye * Have a CST of ≥ 325 μm in the study eye on SDOCT as determined by the IRC at Screening * Have a decrease in vision in the study eye determined by the Investigator to be primarily the result of BRVO BRVO-specific Exclusion Criteria Participants must not: * Have macular edema in the study eye considered to be secondary to a cause other than BRVO (e.g., DME, Irvine-Gass syndrome) * Have active iris or angle neovascularization or neovascular glaucoma in the study eye * Have proliferative retinopathy, central retinal vein occlusion, or hemiretinal vein occlusion DME-specific Inclusion Criteria Participants must: * Have Type 1 or Type 2 diabetes mellitus and a glycated hemoglobin A1c (HbA1c) of ≤ 12% * Have a ETDRS BCVA letter score between ≤ 70 and ≥ 35 (20/40 to 20/200 Snellen equivalent) in the study eye * Have a CST of ≥ 325 μm in the study eye on SDOCT as determined by the IRC at Screening * Have a decrease in vision in the study eye determined by the Investigator to be primarily the result of DME DME-specific Exclusion Criteria Participants must not: * Have macular edema in the study eye considered to be secondary to a cause other than DME (eg, retinal vein occlusion, Irvine-Gass syndrome) * Have active iris or angle neovascularization or neovascular glaucoma in the study eye * Have high-risk proliferative diabetic retinopathy characteristics in the study eye NVAMD-specific Inclusion Criteria Participants must: * Be ≥ 50 years of age * Have a ETDRS BVCA letter score between ≤ 70 and ≥ 35 (20/40 to 20/200 Snellen equivalent) in the study eye * Subfoveal CNV secondary to AMD, with a total lesion size (including blood, scar/atrophy \& neovascularization) of ≤ 9-disc areas, of which at least 50% must be active CNV in the study eye * Have a CST of ≥ 325 μm in the study eye on SDOCT as determined by the IRC at Screening * Be treatment naïve with vision loss in the study eye secondary to NVAMD diagnosed within 21 days prior to the Day 1 study treatment NVAMD-specific Exclusion Criteria Participants must not: * Have had previous thermal subfoveal laser therapy in the study eye * Have any subfoveal atrophy or scarring, blood over the fovea, or subfoveal fibrosis in the study eye. Additionally, no more than 25% of the total lesion size may be made up of scarring or atrophy * Have had previous photodynamic therapy with Visudyne in the study eye * Have diabetic retinopathy in the study eye