What is diabetic retinopathy?
Diabetic retinopathy is a microangiopathy, i.e. a disease of the small vessels of the retina, which, as its name suggests, is associated with any type of diabetes, both type 1 and type 2. It is a chronic disease, a frequent cause of blindness in Western countries, and this microangiopathy can cause damage to the retinal vessels that manifests itself in several ways. Either by exudation, i.e. leakage of fluid from the vessels, or by lack of irrigation which produces an area of ischemia or necrosis and by the appearance of abnormal vessels called neovessels which are more prone to bleeding, more prone to produce fibrosis. All this set of alterations will produce diabetic retinopathy, which is classified into two main types. The non-proliferative form where exudation, blood, hemorrhage, exudates… predominate, and the proliferative form where ischemia or lack of irrigation predominate, leading to the appearance of neovessels.
Causes of diabetic retinopathy
The cause of diabetic retinopathy is basically diabetes, both type 1 and type 2. It is true that in type 1 it can be more aggressive and the factor that most affects the pressure of diabetic retinopathy is poor metabolic control or a prolonged time of evolution of diabetic retinopathy. That is why we recommend our patients to have regular checkups when they have diabetes of any type. There are also other associated factors such as elevated glycosylated hemoglobin, elevated cholesterol, obesity, kidney disease, pregnancy, which can cause a patient with diabetic retinopathy to have or worsen its progression.
Symptoms of diabetic retinopathy
Initially, diabetic retinopathy may not produce any symptoms because it does not affect the central area of the retina, it does not affect the macula. When it affects vision it may be due to different causes. It may be due to the appearance of macular edema, i.e., the outflow of fluid from the retinal vessels affecting the macula, or the presence of hemorrhages, or the appearance of a retinal detachment, which is called proliferative and may cause a lifting of the macula and therefore a loss of visual acuity.
Diagnosis and treatment of diabetic retinopathy
The diagnosis of diabetic retinopathy is mainly based on fundus examination. Most of our diabetic patients have protocolized a series of visits depending on the time of evolution or the type of diabetes to visualize the fundus. In this fundus we can observe different lesions, hemorrhages, exudates, as we can see in these slides, which will help us in the diagnosis. In case of doubt or when we want to verify that there is macular edema, it is necessary to perform a series of tests such as optical coherence tomography, angiography and when we suspect areas of necrosis or dyscemia, it is necessary to perform fluorescein angiography.
The treatment of diabetic retinopathy is fundamentally based on good metabolic control, good glycemic control and in those cases in which macular edema exists, it can be treated with intravitreal injections of different products, initially antiangiogenic and if there is no response, long-acting intravitreal corticosteroids can be injected. In those cases that do not respond to treatment with antiangiogenic or corticosteroids, treatment can proceed with vitrectomy, which is an intervention. And in the form of proliferative diabetic retinopathy the treatment is basically laser makes a panphotocoagulation to eliminate the entire area of ischemia and if the proliferative retinopathy is associated with intravitreal hemorrhages or retinal detachment, surgical intervention may be required or may be necessary, which is what is called a vitrectomy.