A 52-year-old man with type 2 diabetes mellitus (HbA1c 9.2%) presents with blurred vision for 3 weeks. On examination, visual acuity is 6/9 in both eyes. Dilated fundoscopy reveals multiple dot and blot hemorrhages, hard exudates in a circinate pattern around the macula, and microaneurysms in the temporal periphery. No vitreous hemorrhage or neovascularization is noted. What is the most appropriate next step in management?