Diabetic Retinopathy

Diabetic Retinopathy, a complication of diabetes, is caused by changes in the blood vessels of the retina, the light-sensing nerve layer in the rear of the eye.

In this condition, blood vessels feeding the retina are damaged, reducing the supply of oxygen to the retina. The damaged blood vessels may also leak blood or fluid. Sometimes, they develop fragile, brush-like branches or scar tissue, to compensate for the reduced oxygen supply.

Duration of Diabetes

The risk of diabetic retinopathy increases with the duration of Diabetes. About 80% of the people with at least a 15-year history of diabetes have blood vessel damage on their retina. The condition is particularly likely to occur at a younger age in juvenile diabetics. Associated other systemic diseases like hypertension, pregnancy, and kidney disease can also hasten the development of Diabetic Retinopathy.

Stages of Diabetic Retinopathy:

Diabetic Retinopathy progresses through the following stages:

Mild Nonproliferative Retinopathy: At this earliest stage, microaneurysms occur. They are small areas of balloon-like swelling in the retina's tiny blood vessels.

Moderate Nonproliferative Retinopathy: As the disease progresses, some blood vessels that nourish the retina are blocked.
Severe Nonproliferative Retinopathy: Many more blood vessels are blocked, depriving several areas of the retina with their blood supply. These areas of the retina send signals to the body to grow new blood vessels for nourishment.

Proliferative Retinopathy: At this advanced stage, the signals sent by the retina for nourishment trigger the growth of new blood vessels. This condition is called proliferative retinopathy. These new blood vessels are abnormal and fragile. They grow along the retina and along the surface of the clear, vitreous gel that fills the inside of the eye. By themselves, these blood vessels do not cause symptoms or vision loss. However, they have thin, fragile walls. If they leak blood, severe vision loss and even blindness can result.

Symptoms:

Diabetic Retinopathy in its initial stages can go undetected. Its symptoms include bleeding in the eye, and blurring or spotting in the vision.

Diagnosis:

A comprehensive medical eye examination and appropriate treatment is the best protection against eye damage due to diabetic retinopathy.

• Painless examination of the inner part of the eyes with the opthalmoscope can diagnose the disease. The eye is first dilated with eye drops.
• Blood tested to assess the sugar level.
• Flourescein angiography performed to determine the exact condition of the retina and the retinal blood vessel changes, which cannot be seen with naked eyes. For this, the flourescein dye is injected into the blood vessel of the hand. When the dye reaches the eye, it will highlight:

  Areas where new blood vessels have formed
  Areas where blood circulation has stopped
  Swellings in the retina

This will help the opthalmologist to formulate the most suitable treatment.

Treatments:

• Controlling the blood sugar level.
• Control and treatment of associated conditions like hypertension or kidney disease.

Laser treatment :

This is the most widely used form of treatment for Diabetic Retinopathy today. The laser is used to seal the leaking blood vessels and reduce swelling. When larger application of the laser beam are scattered throughout more peripheral areas of the retina. If diabetic retinopathy is detected early, photocoagulation by laser surgery retards vision loss. Even in more advanced cases, it reduces the chance of severe visual impairment.

Other Treatments:

Cryotherapy of the retina, using local anesthesia and a cold instrument probe, may help shrink the abnormal blood vessels.

Preventive Measures

Diabetics should have comprehensive eye check-ups at least once annually.
Blood sugar level should be kept under control by following prescribed diet, exercises and medication.