United Nations Diabetes Day | Diabetic retinopathy - a "vision killer" that cannot be ignored

Diabetic retinopathy (DR) is one of the most common and serious microvascular complications of diabetes. It is also the ocular manifestation of end-organ damage in diabetes, which can seriously affect vision and even cause blindness. Epidemiological surveys show that about 25% of diabetic patients in my country also suffer from diabetic retinopathy. With the improvement of people's living standards, the number of DR patients has increased year by year. Taking active prevention and control measures is the key to preventing patients from further deteriorating their vision.

Risk factors for DR

DR is a disease with complex mechanisms. The interaction of multiple factors causes the patient to gradually progress from asymptomatic to blindness. Finding the risk factors for DR and taking appropriate intervention measures for high-risk factors can help prevent the occurrence of DR and delay the progression of DR.

The course of diabetes and adolescence are unchangeable risk factors for DR. The course of diabetes is closely related to the occurrence and development of DR. After 5, 10 and 15 years of diabetes, about 25%, 60% and 80% of patients with type 1 diabetes will develop DR. After 20 years of diabetes, almost all patients with type 1 diabetes and 60% of patients with type 2 diabetes will show varying degrees of DR in the fundus. Adolescence is a risk factor for DR in patients with type 1 diabetes. Diabetes before puberty increases the risk of DR. In addition, pregnancy can also affect the occurrence of DR. DR can progress rapidly in patients with diabetes (especially those with type 1 diabetes) during pregnancy. Patients with type 1 diabetes are three times more likely to develop DR during pregnancy than patients with type 2 diabetes, but this progression is usually short-lived and can quickly subside after delivery. Diabetes that occurs during pregnancy generally does not develop DR.

In addition to unchangeable risk factors, there are some controllable factors that affect the occurrence and progression of DR, and blood sugar is one of the key factors. Studies based on different populations have found that hyperglycemia is an important risk factor for DR in patients with type 1 diabetes. In contrast, blood pressure is a risk factor for DR in patients with type 2 diabetes. Blood pressure-related vascular changes interact with diabetic vascular abnormalities. The risk of DR in diabetic patients increases with the increase in systolic inter-arm blood pressure difference. Strengthening blood pressure control can significantly reduce the risk of DR occurrence and progression. The risk of DR in diabetic patients with poor blood sugar control will increase by 4 times. Early intensive and continuous blood sugar control can reduce diabetic complications including DR.

The relationship between dyslipidemia and DR is still not fully understood. Studies have found that triglycerides are an independent risk factor for DR in Chinese diabetic patients, and controlling blood lipid levels can delay the progression of DR. For newly diagnosed diabetic patients, if lipid metabolism is abnormal, it is still recommended to lower cholesterol and triglyceride levels to prevent microvascular complications. Recent studies have reported that urinary microalbumin and abnormal glomerular filtration rate will also increase the risk of DR. In addition to the above factors, obesity, metabolic syndrome, lack of exercise, inflammatory markers, choroidal thickness, genetic factors, etc. may be associated with the occurrence and development of DR to varying degrees.

Prevention and treatment of DR

Strengthening effective diabetes management is the basis for preventing the occurrence of DR and delaying the progression of DR, such as improving lifestyle, adhering to a diabetic diet, exercising appropriately, quitting smoking, taking medication as prescribed by a doctor, controlling blood sugar and blood pressure, and regularly monitoring blood sugar levels.

Preventive DR screening plays a key role in preventing the occurrence of DR. Since many DR patients have no obvious symptoms in the early stage, treatment is usually delayed. If no DR is found in the fundus during the initial examination, it is recommended that diabetic patients undergo fundus DR screening every 1 to 2 years; for patients with mild, moderate, and severe non-proliferative diabetic retinopathy and proliferative diabetic retinopathy, fundus examinations should be performed every 6 to 12 months, 3 to 6 months, less than 3 months, and less than 1 month, respectively, to clarify the progression of DR.

In the treatment of DR, the use of laser photocoagulation, drugs and vitrectomy should be fully combined with the individual conditions of the patient, and appropriate treatment methods should be adopted in a targeted manner. The occurrence and progression of DR are not uncontrollable. Improving the self-management behavior of diabetic patients, controlling blood sugar and blood pressure well, and changing diet and lifestyle are the core of preventing and controlling DR.

(Text: Wu Dongfang, Chengdu First People's Hospital)