A 52-year-old man with type 2 diabetes mellitus (HbA1c 9.2%) presents with painless, gradual vision loss in both eyes over 3 months. He denies floaters or flashes of light. On dilated fundoscopy, you observe multiple dot and blot hemorrhages, hard exudates arranged in a circinate pattern around the macula, and microaneurysms scattered throughout the posterior pole. There is no neovascularization. His blood pressure is 138/88 mmHg. What is the most appropriate next step in management?