Microvascular complications
Microvascular complications are: retinopathy, neuropathy and nephropathy.
Diabetic retinopathy is one of the leading causes of poor vision and blindness which is 25 times more common in people with diabetes than in the general population. It is important to know that microangiopathy of the retina in diabetes begins before the appearance of clinically visible signs of the disease with changes in the structure and function of the small blood vessels of the retina on the back of the eye where the image of what we see is created. According to the modern classification, the classification of diabetic retinopathy is divided into non-proliferative and proliferative diabetic retinopathy and diabetic maculopathy. In non-proliferative diabetic retinopathy we have changes in the capillaries of the retina due to which they become permeable, create bubbly expansions of the blood vessel walls (microaneurysms) that can burst and then spotty, spotty hemorrhages and edema, hard and soft exudates are seen in the retina. Proliferative diabetic retinopathy is a late stage of the disease in which ischemic areas are formed due to obliteration (clogging) of small blood vessels and as a reaction to ischemia, new irregular, fragile vessels (neovascularization) grow and are prone to bursting and leaking fluid. During growth, the newly created vessels gradually enlarge and branch and the connective tissue that surrounds them multiplies and creates fibrovascular membranes that spread along the surface of the retina or rise into the vitreous. Due to the fragility of their walls the newly formed blood vessels burst and cause bleeding in the retina or in the vitreous body. When bleeding occurs in the vitreous tissue, vision suddenly weakens. The connective tissue grown into the vitreous gradually tightens, causing distortion of the retina and tearing of blood vessels with profuse bleeding and can also cause tractional detachment of the retina (retinal ablation) which results in blindness. Refractory secondary neovascular glaucoma is a very common complication of retinal ischemia.
Diabetic maculopathy is a special form of retinopathy in which pathological microvascular changes affect the area of the macula, the functionally most important part of the retina at the back of the eye. It is the place of greatest visual acuity that allows us to distinguish details when reading or watching television. Changes can develop at any stage of diabetic retinopathy. Due to damage in the area of the macula, the blood vessels become permeable and swelling (edema) of the macula occurs and symptoms of vision impairment occur which are experienced as blurring, distortion of the image and difficulty seeing at night. Diabetic maculopathy is the main cause of visual acuity loss and blindness in people with diabetes.
Retinopathy does not cause noticeable visual disturbances until it is very advanced. Timely laser photocoagulation of the retina is still the basic method of treating diabetic retinopathy. Timely laser treatment is an effective way to treat severe visual impairment. The patient does not recognize the initial stages of diabetic retinopathy so it is very important to identify and regularly monitor the initial reversible changes whose further deterioration can be prevented by controlling variable risk factors (glycemia, blood pressure, fat, not smoking). A complete ophthalmological examination includes: determination of visual acuity, measurement of intraocular pressure and examination of the anterior and posterior segments of both eyes after pupil dilation using pupil dilation drops. For type 2 patients, the first ophthalmological examination is done when the disease is discovered because the disease can last for a long time (20% of patients have retinopathy when the disease is discovered). If there are no signs of diabetic retinopathy the examination is repeated once a year and if changes are found, the ophthalmologist will determine the time of the new examination in order to start timely treatment with laser or drugs. Patients with type 1 diabetes should have their first examination by an ophthalmologist five years after the discovery of diabetes. Women with diabetes who plan to become pregnant are recommended to have an ophthalmological examination before conception, during pregnancy in the first trimester and six months after giving birth. Pregnant women with gestational diabetes do not have an increased risk of developing diabetic retinopathy so regular ophthalmological examinations are not necessary.
