Text author: Dr sc. Bojan Kozomara, dr med.
Diabetic retinopathy is considered a complication caused by diabetes that occurs in the eye. It is caused by changes in the metabolism of the entire body, including the blood vessels of the retina, i.e., the fundus of the eye.
If changes in the eye are not detected in time, this condition can lead to blindness.
Changes in the metabolism of the blood vessels of the retina make them more susceptible to damage, which can subsequently lead to ruptures, bleeding into the retina and vitreous body, and the formation of macular edema. All of these contribute to a decrease in visual acuity.
Macular edema is the most common cause of decreased visual acuity in diabetic retinopathy. This condition, known as diabetic macular edema, affects the central part of our visual field, so patients often complain of blurred central vision (everything they look at directly in front of them), while peripheral vision is usually preserved.
The risk of diabetic retinopathy increases with the duration of diabetes, and it can occur in both type 1 and type 2 diabetes. It is important to note that after 15 years of diabetes onset, about 80% of patients have some form of retinal damage, i.e., some form of diabetic retinopathy.
There are two main types of diabetic retinopathy. The first is called non-proliferative diabetic retinopathy, and it is also the most common type. It usually occurs between 8 and 10 years after the onset of diabetes and is the earliest stage in the development of the disease. At this stage, the ophthalmologist typically creates a plan for frequent monitoring or initiates initial treatments in consultation with the patient, depending on the condition of the fundus.
The second, much more serious type of diabetic retinopathy is called proliferative diabetic retinopathy. This disease is characterized by extensive damage to the blood vessels in the retina, leading to circulation disturbances and so-called “ischemic zones.” These zones are areas in the retina without oxygen and nutrients needed for normal cell function. In an attempt to naturally revascularize the eye or create new blood vessels, dysfunctional vessels are formed, which easily rupture, leading to further bleeding into the eye and greater ischemia. Ultimately, scar tissue is formed, which can lead to retinal detachment (retinal detachment) and blindness.
The most important thing every patient should know is that an ophthalmologist can only treat the consequences, but not the cause of diabetic retinopathy. In other words, the basis of treatment is managing diabetes. Another important note is that the goal of treatment is to preserve the existing vision the patient has, and any potential improvement primarily depends on the stage of the disease and the extent of retinal damage.
The first line of treatment is laser photocoagulation, which seals off the damaged blood vessels in the retina to prevent further bleeding. Additionally, laser photocoagulation targets ischemic zones in the retina, preventing the formation of pathological blood vessels and scar tissue.
If there is significant diabetic macular edema (swelling of the macula), treatment is conducted with anti-VEGF therapy or injections. These aim to reduce swelling, prevent the formation of scar tissue, and preserve the existing visual acuity. Depending on the type of medication, the therapy is administered monthly or every two months as needed.
If the damage is extensive and if no previous therapeutic procedure has been successful, the only remaining option is deep eye surgery or vitrectomy. This procedure aims to remove as much scar tissue from the retina as possible, prevent further bleeding, and remove existing blood in the vitreous body. The effects of this surgery are individual and depend solely on the level of damage present on the retina.
