A Clinical Trial of MK-8748 Compared to Aflibercept in Participants With Diabetic Macular Edema (MK-8748-004)

Inclusion Criteria: The main inclusion criteria include but are not limited to the following: * Has Type 1 or Type 2 diabetes mellitus and a hemoglobin A1c (HbA1c) of ≤12% * Has a decrease in vision in the study eye determined by the Investigator to be primarily the result of diabetic macular edema (DME) * For participants who are treatment-naïve for DME, the diagnosis must have been made within 9 months of screening. For all treatment-experienced participants, the first treatment should have been no longer than 3 years prior to the Screening visit Exclusion Criteria: The main exclusion criteria include but are not limited to the following: * Has had renal failure requiring renal transplant, hemodialysis, or peritoneal dialysis or has renal failure anticipated to require hemodialysis or peritoneal dialysis at any time during the study * Has history of stroke (cerebral vascular accident) or myocardial infarction within 180 days to first dose of study intervention * Has newly diagnosed or previously untreated diabetes mellitus and initiated oral or injectable anti-diabetic medication within 3 months to first dose of study intervention * Has history of cataract surgery and/or minimally invasive glaucoma surgery in the study eye within 90 days of screening * Has any treatment for complications of cataract surgery with steroids or yttrium aluminum garnet (YAG) laser capsulotomy in the study eye within 90 days of screening * Has advanced or uncontrolled glaucoma in the study eye * Has any history of retinal detachment or treatment or surgery for retinal detachment in the study eye * Has active retinal disease other than the condition under investigation in the study eye * Has uncontrolled blood pressure at screening