The eyes are the windows to the soul. Loss of vision and blurred vision can lead to many inconveniences at school and work, and even affect the quality of life. Most people with diabetes are prone to vision loss, why is that? What can we do about it? The total number of people with diabetes in China is nearly 40 million. As the number of people with diabetes increases year by year and advances in the systemic treatment of diabetes have significantly increased the life expectancy of patients, the number of systemic complications has increased accordingly. The ocular complications include diabetic retinopathy, diabetic cataract, diabetic oculomotor nerve palsy, diabetic glaucoma, diabetic refractive changes, etc. Diabetic retinopathy is one of the most serious microangiopathies, and its incidence increases with the duration of the disease and age. Generally speaking, retinopathy is present in 50% of patients with a disease duration of more than 10 years, and in 70% of patients with a disease duration of more than 20 years. The incidence of diabetic retinopathy is higher in the case of uncontrolled blood glucose. And even the application of glucose-lowering medications does not limit the occurrence of retinopathy. According to statistics, 70% to 90% of diabetic patients will develop diabetic retinopathy during their lifetime as the disease progresses, and the latter has become the single most common cause of blindness in middle-aged and elderly people. Nearly 1/5 of type 2 diabetics worldwide already have severe retinopathy when they are diagnosed with diabetes, and as the disease progresses, about 5-10% of patients go blind within 5 years. Data from eye screening clinics in major hospitals in China show that many diabetic patients actually suffer from comorbidities from the day they are diagnosed with diabetes. 70% or more of diabetic patients are already suffering from severe diabetic retinopathy, resulting in irreversible visual disability or even blindness, which is a very serious problem. Worryingly, the elderly predominate among diabetic patients. When they have some slight changes in their eyes, they often mistake it as a normal decline. In addition, diabetic retinopathy generally begins in the mid-periphery of the retina, and its onset has no obvious effect on vision, so we advise diabetic patients not to go to the ophthalmology office based on whether or not they can see well in their eyes. Patients should be concerned and screened for ophthalmic comorbidities as soon as they are diagnosed with diabetes to avoid delays. And when they develop ocular symptoms: such as vision loss and diplopia, they should visit the ophthalmology department in time to examine the fundus with dilated pupils to detect and treat diabetic retinopathy. Manifestations and dangers: Diabetic retinopathy (PDR) is divided into two main stages, namely non-proliferative and proliferative retinopathy. Non-proliferative (background) diabetic retinopathy is the early stage in which diabetes affects the retina and is the most common cause of visual impairment in patients with type 2 diabetes. Increased blood glucose causes an increase in systemic capillary permeability, platelet activity, and blood viscosity, slowing blood flow and inadequate retinal supply. Microangiomas and hemorrhages appear in the fundus retina, after which the plasma components leak into the retina and yellowish-white dots exude, and in severe cases, retinal nerve fiber infarction and necrosis occur, with white feathery exudate. Retinal vascular exudation and hemorrhage can in turn lead to retinal edema. If the lesion invades the macular region of the retina, the hemorrhage and exudation are right in front of the macula, blocking the image of the object, and a central dark spot can be found in the visual field along with vision loss and distortion. If the disease does not receive effective treatment, the retinopathy will continue to develop and the ischemia and hypoxia will cause new capillaries to grow on the retina and enter the stage of proliferative retinopathy. At this point, the lesions in the fundus are irreversible. If a small retinal vessel ruptures and a small amount of bleeding enters the vitreous, the patient will see a black shadow floating in front of his eyes; if a large amount of bleeding enters the vitreous cavity, the patient will feel a red or black floating object in front of his eyes that won’t go away. And the collection of blood prevents light from entering the retina, which leads to vision loss. As the bleeding in the fundus is absorbed, the color of this floater lightens and the symptoms of blurred vision improve. However, repeated hemorrhages and incomplete absorption are replaced by vascular degeneration with mechanized strips that continuously pull on the retina causing retinal detachment, which can lead to blindness in severe cases. In general, diabetic retinopathy develops to a similar degree in both eyes, and patients who lose their eyesight in one eye are often unable to escape from the other eye. Prevention and treatment tips The prevention of diabetic retinopathy should pay attention to two points: First, good control of blood glucose, blood pressure and blood lipids, and strict abstinence from smoking can reduce the occurrence and development of diabetic complications and prevent their harmful effects on the retina. Secondly, regular fundus examination, timely detection of retinopathy and selection of appropriate treatment timing are the keys to reduce vision loss in diabetic retinopathy. Corresponding medical treatment should be given for different types of diabetes. Diabetic patients should have their glycosylated hemoglobin checked every 2 to 3 months or fructosamine checked every 3 weeks to understand the progress of the disease. In addition, in accordance with international regulations, patients with type 1 diabetes should begin routine eye examinations five years after the onset of the disease, and patients with type 2 diabetes should begin screening for retinopathy at the same time diabetes is detected. For diabetic patients without retinopathy, annual fundus exams are required. Patients with background diabetic retinopathy should have their fundus checked every 2 to 4 months and undergo fundoscopy and be given laser photocoagulation therapy in a timely manner to maintain good vision. Treatment Diabetic retinopathy is more difficult to treat. Because the development of retinopathy is closely related to the control and duration of diabetes, as well as other systemic diseases, such as hypertension and renal disease, there are no specific drugs that are well targeted for the treatment of this disease. However, modern medicine is not helpless in treating the ocular complications of diabetes, and the ideal treatment is laser photocoagulation. Funduscopy can help detect early retinopathy, and fluorescence angiography can indicate the site of retinal vascular leakage, and then apply an accurate laser beam to directly coagulate and close the retinal vascular leakage, effectively controlling the development of diabetic retinopathy and reducing vision loss in patients with progressive retinopathy. However, even the correct photocoagulation treatment is itself a pathological process that may cause some damage to vision and visual field. Timing the laser treatment is very important for the patient’s prognosis. Vitrectomy can be performed for those with large hemorrhages or those who have caused retinal detachment, using special surgical instruments to remove the hemorrhage and scar tissue from the eye. This measure can help restore vision in patients with early hemorrhage. In conclusion, once diabetes is diagnosed, an eye examination should be performed as soon as possible and there should be long-term follow-up. Diabetes is a lifelong disease, and patients with diabetes should not neglect the importance of regular follow-up observations in the ophthalmology department because they feel they can still see. If you only seek medical attention when an underlying lesion flares up and causes vision loss, you may miss the best time for treatment and cause irreparable damage. It should be emphasized that when diabetic patients have both cataract and diabetic retinopathy, they should not undergo cataract surgery hastily. It is recommended to go to a hospital with good conditions for detailed eye examination, and it is best to seek laser treatment for fundus lesions before cataract surgery. Otherwise, once complications arise from the surgery, it will be very difficult to treat the fundus lesions again. Very few patients are found to have diabetic eye disease at the first visit to the ophthalmology department due to blurred vision, and are then diagnosed with diabetes after undergoing other related tests on the advice of the doctor.