Diabetes mellitus is a hereditary illness caused by an alteration in sugar metabolism: diabetes causes alteration of blood vessels throughout the body, in particular, small vessels (capillaries), which carry blood to the tissues and exchange oxygen with for nourishment.
Diabetic retinopathy is a localized manifestation of diabetes. Although every eye structure may be affected by the disease, the retina, rich in capillary vessels, is particularly affected by it.
In the event that the blood hemorrhage extends to the vitreous body, the light rays can no longer pass through and reach the retina as is done under normal conditions, thus causes sudden loss of sight.
The retinal detachment caused by diabetic retinopathy is said to be traumatic: the neovasculars grow from the eye retina in the scaffold provided by the vitreous body. During this growth, membranes stick to the retina.
Diabetic retinopathy usually affects the peripheral areas of the retina, but if the macula is affected, it may be possible, even at early stages, to obscure and reduce vision. Sudden vision loss may be due to intraocular hemorrhage or occlusion of a large vessel (thrombosis), which blocks the blood flow to the retina more or less completely.
In addition to the retinal fluoroangiography examination that allows for a detailed study of the retina and choroid blood circulation, the OCT (optical coherence tomography) is irreplaceable to complete the information provided by the former.
Diabetic retinopathy is a severe form of metabolic alteration of the retina. Diabetes affects about 4% of the population in a country like Italy and therefore there are many sick people who can develop a series of alterations affecting various organs. Diabetes is a disease in which the blood sugar levels are too high due to an error in the metabolism and the endogenous insulin produced by the subject fails to lower these levels.
The sugar in the blood, in an excessive way, is eliminated from the body through the urine when they exceed a certain threshold, but remaining in the blood creates a series of damage within the microcirculation, which is formed by the capillaries, and they, which are used to supply our whole body, begin to have diabetic microangiopathy. Diabetic microangiopathy is a specific disease of the microcirculation, that is, the small capillaries begin to close, obliterate and not function properly; this generates a cascade of effects including local ischemia at the level of various organs.
The organs most affected in diabetes are the kidneys, the heart, the nerves and above all the eye, which has a characteristic that none of the other organs have: the ability to be analyzed without having to be cut and scanned with CT scans, magnetic resonances or other diagnostics. Using images, the eye, therefore, can be analyzed with a simple ophthalmoscope, with a simple camera.
Diabetic patients undergo serial eye checks in specialized clinics to try to understand if there are first signs of diabetic retinopathy.
Diabetic retinopathy presents with alterations of the microcirculation, therefore with a reduction in the amount of blood that reaches the eye, which is detected by the ophthalmologist with specific pathognomonic signs, i.e. the ophthalmologist can understand what degree of diabetic retinopathy is attacking the eye of the patient.
This serves to give a prognosis, to understand how the diabetic disease is going and above all to preserve the patient’s vision, because diabetic retinopathy is one of the main causes of vision loss in our evolved modern Western world.
The patient who comes to the ophthalmologist must perform a direct and indirect ophthalmoscope examination, performed on the spot by the ophthalmologist who then must request a retinography, which is now routine in Anglo-Saxon countries and must also be so in ours, because it serves to document the state of health of the patient’s retina.
Another exam that can be done is the OCT, the Optical Coherence Tomography: it is used to understand the state of health of the central area of the retina, so if there is a suffering of the retina itself with edema.
Diabetic retinopathy causes alterations that are called microangiopathies, therefore alterations in the microcirculation with hemorrhages, microaneurysms and exudation, that is, within the vessels the blood circulates little, badly and tends to escape from the vessel wall, which loses its ability to retain liquids.
So few of the main pathognomonic signs are hemorrhages, exudates, microaneurysms and above all edema, that is, the increase in the amount of liquid that stagnates in the retina.
The retina is a film that serves to see and if soaked in water it works incorrectly, so the patient begins to have symptoms.
Diabetic retinopathy should not be treated when it only shows symptoms but must be prevented, so you have to go to the ophthalmologist, who must perform the tests mentioned above (i.e. retinography and OCT) and must address the diabetic patient as soon as possible, who develops signs of diabetic retinopathy, through a parasurgical or surgical act to preserve the vision.