Diabetic retinopathy

The article was written by Specialist II Doctor Nguyen Xuan Thang - Department of Medical Examination & Internal Medicine - Vinmec Central Park International General Hospital

Diabetes mellitus (DM) is increasing worldwide and there are more and more complicated complications, in which diabetic retinopathy is a matter of concern. Approximately one-third of patients with type 2 diabetes develop some degree of diabetic retinopathy within 5 years. Within 15 years of having diabetes, about 60-85% of people with type 2 diabetes will have diabetic retinopathy.

Diabetic fundus complications, also known as diabetic retinopathy, belong to the group of small vessel complications of diabetes.
Diabetic retinopathy is caused by chronic hyperglycemia that destroys the capillaries on the retina of the eye, leading to capillary leakage and blockage causing vision loss. In addition, diabetes can also cause cataracts, glaucoma, double vision, decreased ability to focus eyes.
In the early stages, patients with diabetic retinopathy are often asymptomatic. However, as the disease progresses, patients may experience blurred vision and gradual loss of vision. Controlling multiple risk factors should be able to reduce the incidence of blindness. Diabetic retinopathy is an indicator of an increased risk of complications or death, often from cardiovascular complications, especially in the proliferative stage of retinopathy.

Chronic hyperglycemia Disturbance of autoregulation of retinal blood flow Sorbitol is produced when elevated glucose enters the cell, increasing the osmotic pressure in the cell lumen. Sorbitol accumulation also plays an important role in cataract formation, which can lead to vitreous rupture Advanced glycation end products (AGE) due to glucose binding to free amino acids or serum proteins Cells. AGEs can also deposit and cause cataracts Retinal microthrombotic growth factors IGF 1 and VEGF Carbonic anhydrase concentrations are increased in vitreous in patients with proliferative retinopathy compared with diabetes without Diabetic retinopathy Genetic factors Other factors: Race, drugs, related kidney disease,...

The main cause is chronic hyperglycemia. Increased blood glucose damages blood vessels, which can cause embolism.
Other risk factors for retinal damage:
Duration of diabetes Unstable blood glucose High blood pressure Hypercholesterolemia Pregnancy Smoking smoking

3.1 Diabetic retinopathy and macular edema Nonproliferative diabetic retinopathy:
Approximately 80% of diabetic retinopathy patients are in the nonproliferative stage.
Early stage lesions, no new blood vessels have appeared yet. At this stage, the blood vessel wall is weakened, creating aneurysms, substances in the blood seep through the vessel wall causing exudative spots, blood can also seep through the vessel wall causing hemorrhagic spots.
As the disease progresses, the small blood vessels become blocked, causing regional ischemia in the retina. Larger blood vessels are enlarged and irregular in diameter. The nerve fibers in the retina are also edematous, the central region of the retina is sometimes also edematous, causing macular edema.
Proliferative diabetic retinopathy:
This is the most severe stage of the disease. In retinal hypoxia and the effects of hyperglycemia, due to efforts to supply blood to the ischemic areas, new blood vessels are generated from the retina into the vitreous cavity. Newly created blood vessels often grow out of place, and the vessel walls are also very weak. These blood vessels can grow and bleed into the vitreous causing severe vision loss, and scar tissue caused by vascular proliferation can cause retinal detachment. If these newly formed blood vessels grow into the drainage path of fluid leaving the eyeball, pressure can build up in the eyeball causing glaucoma. The stage of proliferation, fibrosis, and retinal detachment.
Macular edema:
The thickening of the central part of the retina due to thickening of the basement membrane and a decrease in the number of perivascular cells increases vascular permeability and leakage of plasma components into the retina, causing retinal edema. About 11% of patients with diabetic retinopathy have macular edema. About 1-3% of patients lose vision due to macular edema. Optical coherence tomography (OCT) is the most sensitive method for determining the location and extent of macular edema.

3.2. Eye diseases can be aggravated by the effects of diabetes Refractive changes Diplopia Cataracts Glaucoma (Glocom)

In the early stages, the patient may not feel anything unusual
As the disease progresses, you may experience:
Sensation of black spots (flying flies), or black fibers in front of the eyes Blurred vision, knife image Motion Seeing black areas or empty areas in a scene Blind, loss of color perception

Principles:
Well control risk factors, accompanying systemic diseases. + Treatment of eye complications depends on the stage of the disease, including treatment of retinal neovascularization in proliferative diabetic retinopathy and reduction of vascular permeability, reduction of fluid leakage in macular edema.
Nonproliferative retinopathy: Usually no treatment is needed, unless the macular edema is clinically symptomatic, central macular edema and/or severe macular edema. Intraocular anti-VEGF injection or laser treatment.
Proliferative retinopathy: The goals of treatment are to improve or preserve vision, reduce the rate of progression and frequency of vitreous hemorrhage, and repair retinal detachment when needed. Anti-VEGF injection, total laser treatment, vitrectomy, intraocular glucocorticoid injection,...

Good blood sugar control . Target HbA1C less than 7%. Blood pressure control: The goal is less than 140/90 mmHg. Good control of blood pressure can reduce the incidence of diabetic retinopathy and reduce the progression of the disease, reducing the risk of vitreous hemorrhage. Controlling blood lipids: Studies show evidence that Fenofibrate group of drugs has the effect of reducing the progression of diabetic retinopathy, preventing retinopathy from progressing to the stage that requires more laser by the following mechanisms: Transporting blood lipids back and forth in the retina, preventing fat accumulation and poisoning and capturing free radicals, protecting the retina from oxidative stress.
+ Prevents endothelial cell death
+ Prevents retinal neuron degeneration
+ Anti-oxidant and anti-inflammatory
+ Protects against retinal vascular barrier breakdown
+ Anti-proliferative vascular
+ The retinal protective benefit of Fenofibrate is independent of the patient's lipid profile
Antiplatelet agent
Other measures: Omega 3, Carbonic anhydrase inhibitor, calcium dobesilate
Early detection lesions in the fundus will help to promptly manage and prevent the progression of complications (ophthalmoscopy, fluorescein angiography, OCT):
+ It is necessary to screen for this complication by appointing an appointment. fundus examination annually in patients with type 2 diabetes at diagnosis and thereafter annually by an ophthalmologist. For patients with type 1 diabetes, fundus examination is indicated 5 years after diagnosis.
+ If blood glucose stabilizes well, blood pressure is not high, and there is no abnormality of blood lipids, the doctor may decide to re-examine the fundus after 2-3 years.
If the diabetic patient is pregnant, it is necessary to have regular fundus examination because pregnancy can easily damage blood vessels in the fundus.
Lifestyle changes: Exercise, eat right, stop smoking.
Diabetic retinopathy can cause vision loss and permanent blindness. Good control of blood glucose and blood pressure are the most effective methods to prevent this complication. Periodic disease screening by ophthalmoscopy, fluoroscopy or OCT will help identify the nature and extent of complications early for timely intervention.
Vinmec International General Hospital is one of the hospitals that not only ensures professional quality with a team of leading medical doctors, a system of modern equipment and technology. The hospital provides comprehensive and professional medical examination, consultation and treatment services, with a civilized, polite, safe and sterile medical examination and treatment space. Customers when choosing to perform tests here can be completely assured of the accuracy of test results.

References:
American Diabetes Association. Diabetes Care. 2020 International Diabetes Federation (2015). A guide for health care professional.