Diabetic retinopathy

Diabetic retinopathy: description

Diabetic retinopathy (retinal diabetic disease) refers to damage to the retina (retina) in the eye due to high blood glucose levels. It can occur in type 1 diabetes as well as type 2 diabetes.

The retina consists of specialized nerve cells (photoreceptors), which transform the eye-catching light rays into nerve impulses. A high blood sugar level damages the small blood vessels in the retina, so that the photoreceptors get too little oxygen. In advanced stages, there are new but unstable blood vessels in the retina. Those affected see increasingly worse and can even go blind in severe cases. Diabetic retinopathy is the most developed in industrialized countries most common cause of blindness in middle age.

Physicians distinguish in the diabetes-related neoplastic dermatitis two different stages of disease: the initial stage is the nonproliferative diabetic retinopathy, This may be after years in the proliferative diabetic retinopathy go over, in which a blindness threatens. In addition to these two stages there is a special form of the disease in which the retina is damaged, especially in the area of ​​the macula (yellow spot, place of the sharpest vision): the diabetic maculopathy.

Non-proliferative diabetic retinopathy

Non-proliferative means that no neovascularization (neoangiogenesis) takes place in the area of ​​the retina at this stage of the disease. But even now the tissue in the eye is poorly perfused, so that the retinal cells receive too little oxygen.

This hypoperfusion triggers typical structural changes in the retina, which the ophthalmologist can see when examining the fundus. The patient himself often does not notice anything about his condition at this stage. Only some patients report visual field defects (due to retinal bleeding) and gradual deterioration of vision.

Proliferative diabetic retinopathy

In the advanced stage, the body tries to compensate for the significant lack of oxygen in the retina by the formation of new blood vessels (vascular proliferation). However, these are very unstable and tend to break or burst. The result is frequent bleeding and fluid retention in the retina. Also in the iris (Rubeosis iridis) and around the junction of the optic nerve into the retina (optic nerve papilla), such new vessels form.

Proliferative diabetic retinopathy is a serious threat to the eyesight of patients. In most cases, the sight is already severely restricted anyway. At this stage, however, threatens the complete blindness.

Diabetic maculopathy

Diabetic maculopathy is a special diabetic retinopathy. Here, the place of the sharpest vision (macula) in the area of ​​the retina is particularly affected by the permanently elevated blood sugar levels. Patients therefore have great difficulties in everyday life, for example when driving or reading.

Diabetic retinopathy: symptoms

Due to the damage of the nerve cells of the retina is the Eyesight increasingly worse, This is going on for a few years. The damage, especially in the first few years of disease, often progresses slowly, but can accelerate later. It is usually noticed late by those affected.

But diabetic retinopathy can also show acute symptoms: When a retinal vessel tears and hemorrhages in the retina occur suddenly dark spots in the field of vision appear. With a larger hemorrhage, the blood can also enter the vitreous body of the eye and cause a so-called vitreous hemorrhage. Affected see this passing black dots (“Rußregen”). In addition, diabetic retinopathy in an advanced stage can Retinal detachment(Ablatio retinae). She goes through, for example flashes of light and sudden Visual field defects noticeable.

Diabetic retinopathy: causes and risk factors

Diabetic retinopathy is caused by permanently increased blood sugar levels caused. The worse the blood sugar is adjusted, the more likely a diabetic retinopathy develops.

In the case of those affected, the many sugar molecules in the blood damage the inner walls of the smallest blood vessels (capillaries). This damage is also called microangiopathy. It affects all the tiny vessels in the body, but especially the retinal vessels and the renal vessels.

If the nerve cells of the retina are no longer adequately perfused and supplied with oxygen due to vascular damage, they die. In addition, the damaged capillaries can be leaking. The resulting blood leakage also damages the nerve cells of the retina.

In addition to high blood sugar also carry other risk factors to damage the small vessels in the eye. This includes:

• high blood pressure (arterial hypertension)
• Smoke
• elevated cholesterol levels (and other lipid levels)
• hormonal changes, for example during puberty or pregnancy

Diabetic retinopathy: examinations and diagnosis

The diagnosis “diabetic retinopathy” is usually made by the ophthalmologist. This usually leads first to a detailed conversation with you as a patient to raise your medical history (anamnese). Describe your ophthalmologist in detail your symptoms. Often the doctor also asks questions such as:

• How long have you been suffering from diabetes?
• Do you often see blurry lately?
• Do you sometimes see black dots that seem to fly by?
• Do you suffer from hypertension?
• Do you smoke?
• Are you aware of high blood lipids or elevated cholesterol?

To diagnose diabetic retinopathy, the Ophthalmoscopy the most important investigation. The doctor looks at the fundus. The examination is completely painless.

In diabetic retinopathy, the damaged blood vessels may be visible in the fundus depending on the stage of the disease. In addition, vascular grafts (aneurysms), retinal haemorrhages, “cotton wool flocks” and deposits of fats in the retina (“hard exudates”) can sometimes be seen.

Further investigations

Sometimes further investigation is needed to further clarify diabetic retinopathy. This includes, for example, the fluoresceinwith which the vessels of the retina can be displayed. With the Optical coherence tomography (OCT) In addition, the location of the sharpest vision (macula) can be examined more closely.

Diabetic retinopathy: treatment

Diabetic retinopathy is caused by high blood sugar levels. The best therapy is therefore the best possible blood sugar adjustment. Any existing risk factors should also be addressed. In addition, special ophthalmic treatments may potentially slow the progression of the disease.

Blood glucose control

In diabetes therapy, a long-term blood sugar level (HbA1c) between 6.5 and 7.5 percent is generally sought. Individually, the treating physician can specify a different therapeutic goal. For example, if high blood glucose levels have already damaged middle and large vessels (such as leg vessels or coronary arteries), the HbA1c should be between 7.0 and 7.5 percent. If there is already kidney damage (diabetic nephropathy), scores of less than 7.0 percent are often targeted.

risk factors

Any existing risk factors for vascular damage must also be treated to prevent the increased damage to the retina. One of the most important therapeutic measures is the drug setting of an elevated blood pressure value. In addition, increased blood lipid levels (cholesterol, triglycerides) should be lowered by dietary measures. In addition, patients should abstain from alcohol and nicotine because these stimulants are also bad for the vessels.

Ophthalmological treatment options

An advanced diabetic retinopathy can be treated by means of a laser therapy and the injection of drugs into the eye. If hemorrhages occur in the vitreous, the vitreous can be removed and replaced with a clear liquid.

Laser therapy: The patient receives a local anesthetic. In several sessions over the course of a few weeks, a laser causes specific scarring on the retina (laser coagulation). In this case, only already pathologically altered retinal areas are scarred, but the nerve cells are spared as possible. By eliminating the pathologically altered retinal areas, the total oxygen requirement of the retina is reduced. The healthy retinal components thus have more oxygen available.

The laser therapy can prevent a threatening blindness. But it has side effects. Only in about half of the patients the pre-existing visual acuity is maintained. After treatment, visual disturbances in the dark (night blindness) as well as a limitation of the visual field can occur. As a result of the procedure, water can also accumulate in the retina (retinal edema).

Injection of drugs into the vitreous: This intravitreal injection comes into question when the diabetes has led to swelling at the site of sharpest vision (macular edema) with the involvement of the fovea. Usually then so-called VEGF inhibitors are injected. These agents can inhibit pathological vascular growth in the eye. If this therapy does not work, then a cortisone may be injected into the vitreous body. It has a vaso-sealing effect and thus helps against the swelling. However, cortisone injections increase the risk of gray and green star (cataract and glaucoma).

Some of the drugs used are not officially approved for intravitreal injection in macular edema. Their use thus takes place “off-label”. They may only be used if the patient is first informed in detail about the effect and side effect of the drug and gives written consent.

Vitreous removal (vitrectomy): Diabetic retinopathy is sometimes associated with bleeding into the vitreous of the eye or retinal detachment. Hemorrhages in the vitreous affect vision. In addition, the vitreous may be abnormally altered especially in an existing diabetic retinopathy and thus cause retinal detachment. In these situations, it makes sense to remove the almost completely made of water glass body (vitrectomy). This happens under local anesthesia. After removal of the vitreous, the remaining cavity is filled with a liquid or gas. After the procedure, the risk of cataracts may be increased.

Diabetic retinopathy: disease course and prognosis

Diabetic retinopathy is a chronic disease that can lead to complete blindness within a few years from a complaint-free condition. Due to the lack of oxygen more and more nerve cells in the retina irreversibly die. As a result, the vision deteriorates increasingly. In addition, numerous complications such as increased intraocular pressure (cataract) and retinal detachment. In some diabetic patients (less than one percent), diabetic retinopathy leads to complete blindness.

So far the disease can not be cured. But with proper treatment, their progression can often be slowed down. However, the decisive factor for the prognosis is how well the person concerned succeeds in stopping the blood sugar and eliminating further risk factors for diabetic retinopathy (hypertension, smoking, etc.).

When should you go to the ophthalmologist!

In order for a diabetic retinopathy to be detected in time, diabetics should consult an ophthalmologist at regular intervals:

• If there are still no retinal changes and no particular risk for it, will be an eye exam every two years recommended.
• If there are no retinal changes, but there are other risk factors (such as high blood pressure, high blood lipid levels, etc.) in addition to the high blood sugar, the ophthalmological examination once a year respectively. This also applies if it is not clear whether a patient has such other risk factors.
• If there are already diabetes-related retinal changes, patients should at least once a year consult the ophthalmologist. He will decide at which intervals a check-up in individual cases is necessary.

If new symptoms occur in the eye area such as a new vision deterioration, blurred vision or “sooty rain” in front of the eyes, diabetics should go to the ophthalmologist immediately. That’s how one can be Diabetic retinopathy or recognize their deterioration in good time.