A Study to Investigate RO7200220 as Monotherapy and in Combination With Ranibizumab in Participants With Diabetic and Uveitic Macular Edema

Inclusion Criteria: DME Participants: * Diagnosis of Diabetes Mellitus (DM) (Type 1 or Type 2), as defined by the World Health Organization and/or American Diabetes Association * Macular edema associated with DR defined as macular thickening by spectral domain optical coherence tomography (SD-OCT) involving the center of the macula: central subfield thickness (CST) of ≥325 μm with Spectralis. * Decreased visual acuity (VA) attributable primarily to DME, with BCVA letter score of 73 to 19 letters (both inclusive) on Early Treatment Diabetic Retinopathy Study (ETDRS)-like charts (20/40 -20/400 Snellen equivalent). * Clear ocular media and adequate pupillary dilation to allow acquisition of good quality retinal images to confirm diagnosis. UME Participants: * Diagnosis of noninfectious uveitis (NIU) of any anatomical type (anterior, intermediate, posterior, panuveitis). Active and inactive NIU is allowed. * Macular edema associated with NIU defined as macular thickening by SD-OCT involving the center of the macula: CST of ≥325 μm with Spectralis. * Decreased VA attributable primarily to UME, with BCVA letter score of 78 to 19 letters (both inclusive) on ETDRS-like charts (20/32 - 20/400 Snellen equivalent). * Sufficiently clear ocular media and adequate pupillary dilation to allow acquisition of good quality retinal images to confirm diagnosis. * Either treatment naive or previously treated in the study eye or systematically (with washout periods and maximum doses applicable for specific treatments). Exclusion Criteria: * Any major illness or major surgical procedure within 1 month prior to Day 1 * Any febrile illness within 1 week prior to screening or Day 1 * Any stroke or myocardial infarction within 12 months prior to Day 1 * Any active proliferative DR (DME participants only) * Panretinal photocoagulation or macular laser photocoagulation treatment prior to Day 1 * History of vitreoretinal surgery/pars plana vitrectomy * Any cataract surgery within 3 months prior to Day 1 or any planned surgery during the study * History of any glaucoma surgery including laser glaucoma procedures * Uncontrolled glaucoma * History of rubeosis iridis * Any active ocular or periocular infection on Day 1 * Any presence of active intraocular inflammation on Day 1 or any history of intraocular inflammation (DME participants only) * Any prior or concomitant periocular or IVT corticosteroids in the study eye (DME treatment naive participants only) * Use of any systemic corticosteroids within 1 month prior to Day 1 (stable oral prednisone for UME participants allowed) * Any prior or concomitant systemic anti-VEGF treatment within 6 months prior to Day 1 * Any concurrent use of biologics for immune-related diseases