Diabetic retinopathy

Diabetes mellitus

Recently, diabetes has become a very common disease. Both adults and children may have diabetes and doctors associate their growing number with the fact that in modern society, particularly in big cities, there are numerous risk factors for this disease, including bad environment, excessive weight, irrational nutrition, limited physical activity, immobility, stresses, and chronic fatigue.

Specialists believe that by the year of 2025, the number of diabetes patients may reach a critical number of 300 million which is about 5% of the world population.
Diabetes mellitus is associated with high blood sugar level. In a normal state, the cells of the pancreas (beta cells) produce insulin – the hormone which governs metabolism, primarily that of sugar (glucose) in the blood, and also of fats and proteins. It is a known fact that sugar is essential for normal functioning of human cells.
Insulin deficiency in the case of diabetes not only keeps the cells on a “hungry diet” but also leads to a growing amount of unclaimed sugar in the blood. In its turn this excessive sugar leads to disrupted metabolism of fats, the accumulation of cholesterol in blood, and the formation of hemoliths in the blood vessels. This leads to gradual narrowing of the blood vessels which slows down the blood circulation to the extent of full stoppage.
Diabetes mellitus creates hazards for heart, eyes, visual apparatus, blood vessels in the legs, and kidneys.

Diabetic retinopathy usually develops over 5-10 years after the beginning of diabetes. In case of diabetes of the 1st type (insulin dependent), diabetic retinopathy develops very rapidly and soon it transforms into proliferative diabetic retinopathy. In case of diabetes of the 2nd type (insulin dependent), the change occur mainly in the central zone of the retina, provoking diabetic maculopathy. It may often be cystic, leading to deterioration of central vision.

The causes for diabetes mellitus:

• Genetic predisposition
• Excessive weight
• Various diseases which damage the insulin-producing beta-cells. These are disorders of the pancreas – pancreatitis, pancreas cancer, disorders of other internal secretion glands
• Viral infections (German measles, smallpox, epidemic hepatitis, and other diseases including flu). These infections trigger disorders in people from the risk group.
• Nervous stress. People in the risk group should avoid nervous and emotional stress.
• Age factor. Every ten years of life doubles the probability of diabetes.

Apart from constant weakness and fatigue, dizziness and other symptoms, diabetes considerably raises the risk of cataract and glaucoma, as well as damages of the retina. One of the manifestations of diabetes is diabetic retinopathy.

In almost 50% of cases diabetic retinopathy cannot be diagnosed and is often identified only after the development of complications.
According to the World Health Organization (WHO), diabetic retinopathy is identified in 80-99% of patients with diabetes mellitus of the first type (duration of the disease 15-20 years).

How does diabetic retinopathy develop?

Diabetes leads to changes in the blood vessels of the retina which results in oxygen deficiency in the retina. This state of the visual system eventually brings to the development of diabetic retinopathy which is a gradual process and even in its pronounced stages it may not be felt by the patient.

The main symptoms of diabetic retinopathy:

• Blurred vision
• Appearance of spots before the eyes
• Hemorrhage into the retina and vascular body
• Poor vision which usually indicates advanced stages of retinopathy.

There are two forms of diabetic retinopathy:

Background retinopathy
Background retinopathy is characterized by pathological changes within the retina. Damage in the capillary vessels of the retina leads to small hemorrhages, deposition of metabolism products and edemas of the retina. This type of disorder affects people with a long case history of diabetes and leads to slow deterioration of vision.

Proliferative diabetic retinopathy
Proliferative diabetic retinopathy develops from background retinopathy due to the growing oxygen deficiency in the retina. This form results in the creation of new blood vessels which grow from the retina into the vitreous body and produce hemorrhage and growing deterioration of vision.

In a young patient, this development may occur within the period of a few months. The further development of the disorder leads to the retinal detachment. In this country, such a form of diabetic retinopathy is the most common cause for blindness of the able-bodied population.

Diagnostics of diabetic retinopathy

In order to confirm or refute the diagnosis of “diabetic retinopathy”, it is necessary to undergo a comprehensive diagnostic testing of the visual system. The Excimer Eye Clinic performs diagnostics with help of the latest computer-based equipment which provides a full picture of patient’s vision.

Diagnostic testing of patients with diabetic retinopathy includes not only standard procedures but also:

• Testing of the fields of vision (perimetry) in order to assess the state of the retina in its peripheral zones;
• Electrophysiology testing to estimate the viability of the nervous cells in the retina and the optic nerve;
• Ultra-sonic testing of the interior structures of the eye – A-scanning, B-scanning;
• Measurement of intra-ocular pressure (tonometry);
• Research of the eye fundus (ophthalmoscopy),

It is important to remember that patients with diabetes must see an ophthalmologist at least twice a year and undergo diagnostics of vision. This allows the doctors to make a timely diagnosis of the development of eye complications and begin treatment as soon as possible.

Treatment for diabetic retinopathy

The treatment method for diabetic retinopathy depends to a great extent on the stage of the disorder. At present, the most effective and reliable method for preventing development of diabetic retinopathy is laser photocoagulation of the retina.

Laser photocoagulation is performed on an out-patient basis and does not require admissions. Local anesthesia is applied in the course of the procedure to exclude any pain. The purpose and method of laser treatment lies in the coagulation (cauterization) of the most damaged “leaking” blood vessels in the retina and a possible creation of temporary channels for the drainage of accumulated intra-retinal fluid.

Read more about laser photocoagulation of the retina