The purpose of this protocol is to determine whether point of care optical coherence tomography (OCT) imaging combined with an OCT-guided retinal referral algorithm at primary diabetes care visits increases rates of retina specialist eye care for patients with diabetic macular edema. The hypothesis is that OCT imaging with an automated OCT-guided referral algorithm will enable identification of patients at risk for vision loss from diabetic macular edema and facilitate direct referral to retina specialists for more timely evaluation and treatment.