Over the years, diabetes, or better hyperglycemia, has caused a series of chronic complications. Among these, a particularly serious one is Diabetic Retinopathy. If it is not diagnosed and treated appropriately, Diabetic Retinopathy can lead to severe visual impairment, which in the worst cases can lead to blindness. Diabetic Retinopathy is the leading cause of acquired blindness among adults.
Diabetic Retinopathy can be prevented by keeping blood sugar, as well as other risk factors, such as high blood pressure and fat concentration in the blood, under control. Continuous monitoring of these factors prevent them from worsening, even if there are signs of initial retinal damage having occurred.
It is equally important to regularly check, following the advice of your optician and nutritionist, the conditions of your eyes and in particular of the retina
, through diagnostic tests from little to non-invasive as the ocular fundus, a retinography and ocular tonometry. These tests make it possible to diagnose Diabetic Retinopathy early and to treat it in time.
The first step is therefore controlling blood sugar, blood pressure and blood fats, achievable through a gradual and firm change of one’s lifestyle and the pharmacological therapy prescribed by your doctor when necessary. The second step is screening or regular examination of the eye.
A third step has recently been added to the above two: the possibility of treating both diabetes and Diabetic Retinopathy. Medications are available that allow you to check your blood glucose, as well as specific therapies for the treatment of Diabetic Retinopathy.
It is important, however, that the person with diabetes is actively involved in these treatments, that he know the risks he is facing, that he actively undergo regular controls and adopt those behaviors that are essential to prevent chronic complications from occurring and worsening.
Diabetic Retinopathy evolution
The main cause of Diabetic Retinopathy is hyperglycemia or excessive concentration of glucose in the blood, a distinctive factor in poorly controlled diabetes. In many ways, hyperglycemia damages the blood vessels by obstructing or deteriorating them.
In the case of the retina, after many years of having suffered of diabetes, the so-called 'background' or 'bottom' retinopathy is quite common, characterized by loss of blood and liquids from damaged capillaries. At this stage, the patient may not notice anything, because early retinopathy affects the part of the retina that is not used in distinct vision.
This phase can be complicated in two ways: leaked liquids can form of 'bubbles' (macular edema) and damaged and abnormal capillaries can invade more or less extended portions of the retina and the eye (proliferating retinopathy). In both cases, the main factor in the onset of the retinopathy is a substance called VEGF (vascular endothelial growth factor) that promotes the creation of new and abnormal capillaries that are more brittle and porous.
Only part of the retina, the macula
, is used in distinct vision. Usually the damage is first witnessed in outlying areas and only at a later stage involves the central part (macula). At that point, vision is already compromised. This means that the patient may not notice the developing retinopathy until it is in its very advanced stages. On the contrary, an optician examining the ocular fundus can non-invasively detect retinopathy early on.
Diabetic Retinopathy is proliferating in 23% of people with diabetes type 1, in 14% of people with diabetes type 2 treated with insulin and in 3% of people with diabetes type 2 not treated with insulin. The diabetic macular edema is noted in 11% of people with diabetes type 1 and respectively in 15 and in 4% of people with diabetes type 2 who use or do not use insulin.
Diabetic macular edema is a complication of Diabetic Retinopathy and is the most common cause of loss of eyesight in diabetic patients. It is usually classified into two subtypes: focal and diffuse. Diabetic macular edema with visual impairment affects about 1-3% of diabetics. In our country, it is estimated that people with this condition are about 44,000.
From some dilated and permeable retinal capillaries, a liquid pours out that forms retinal thickening areas, ‘bubbles’ often surrounded and delimited by fat, it too leaked from the capillaries. With focal edema, the problem is limited to certain points, while in diffused edema fluid leaking from retinal dilated capillaries is generalized.
The first symptoms are blurred vision and image distortion. The macula is the central portion of the retina responsible for distinct vision, which allows you to read, recognize faces, watch TV, drive and perform other common routine activities.
Other typical symptoms include floaters (the so-called flying flies), altered sensitivity to contrast, the feeling of annoyance when exposed to strong light (photophobia), changes in color vision and scotomata (blind areas in the field of view).
Macular edema causes visual impairment in proportion to its severity: visual impairment is more severe when it concerns the central area of the macula. However, symptoms are manifest only in the more advanced stages of the disease, when vision is by now irreversibly compromised. For this reason, it is essential that diabetic patients submit to regular eye checks with ocular fundus examination, even in the absence of visual disturbance.
How to fight it
The most common cause of visual impairment in the course of diabetes mellitus is represented by the development of Diabetic Retinopathy, characterized by diabetic macular edema and proliferating Diabetic Retinopathy.
Monitoring your blood glucose, blood pressure and blood fat concentration is the most important recommendation in preventing and slowing down the progression of retinopathy. It is equally important to check eye condition at regular intervals.
The evolution of retinopathy can be countered both by further improving glycemic and pressure compensation and with specific therapies.
In the past, the reference therapy for the treatment of diabetic macular edema was the focal or grid laser. The laser beam, focused on the retina, determines a "burning" of the fabric, with a consequent scarring of microaneurysms (anomalies dependent on the capillaries) and a reduction of the leakage of liquids from vessels. The laser is unable, however, to regenerate the diseased retina or to restore lost vision, but allows you to stop the progression of the disease.
Intravitreal drug therapies
Today, the treatment of retinal vascular pathologies has been substantially changed by the advent of intravitreal treatment solutions. It involves administering a medication in the eye that can stop the mechanisms leading to the development of visual problems caused by Diabetic Retinopathy. Early steroid preparations have been joined more recently by substances consisting of monoclonal antibodies that, acting on the principal trigger of the disease, VEGF, can reverse the progression of the edema and determine an improvement in vision. These medications, called anti-VEGF
drugs, require intravitreal injection cycles and have revolutionized the evolution of the disease and the future vision and quality of life of patients suffering from these complications.
Surgical therapy is implemented in the most severe cases and consists in the removal of the vitreous (vitrectomy).