Diabetic retinopathy (DR), a complication of DM, is one of the leading causes of blindness in the world, and research has demonstrated that approximately 25% of hospitalized patients were unaware of their diabetic status, with their initial diabetes diagnosis occurring as a result of an ophthalmologic examination. In the US, only half of the patients diagnosed with diabetes undergo DR screening. Without treatment, it has been shown that the 5-year cumulative rate of severe vision loss is 12% in patients with non-proliferative diabetic retinopathy (NPDR) and rises to 50% in patients with proliferative diabetic retinopathy (PDR) with high-risk characteristics. However, with treatment, the 5-year cumulative rate of severe vision loss decreases by about 30%. Therefore, vision-threatening complications caused by DR are preventable, making it crucial to take proper measures for early diagnosis and timely intervention.