Ref: CHB/Flash/2006/27                                             Date: October 16, 2006

CHB NEWS FLASH

Overview

Diabetes is a disease that occurs when the pancreas does not secrete enough insulin or the body is unable to process it properly.  Insulin is the hormone that regulates the level of sugar (glucose) in the blood.  Diabetes can affect children and adults. 

In 1995 WHO estimated that by the year 2025 prevalence of diabetes will go up by 120% and more than 80% of the diabetics will be found in the developing countries. Community survey done in Asian community in Dar Es Salaam in late 90s showed that the prevalence of Diabetes in Asians ranges from 6-11%.

Diabetes is the commonest cause of blindness in patients aged 25-65 years in the developed countries.

Diabetic eye disease refers to a group of eye problems that people with diabetes may face as a complication of diabetes. All can cause severe vision loss or even blindness.

A number of factors are associated with increased risk of developing blinding diabetic eye disease, some of these are:

          1. Duration of Diabetes

          2. Poor sugar control

          3. Hypertension

          4. Kidney disease (Nephropathy)

          5. Anaemia

          6. Smoking

          7. High cholesterol and fatty acid levels (Hypercholesterolemia / hyperlipidaemia.

          8. Pregnancy

Common eye problems in Diabetes.

Diabetic eye disease may include:

§         Diabetic retinopathy - damage to the blood vessels in the retina (the “seeing part  

                                      of the eye” – also called “PARDHO” in Gujarati)

§         Cataract                  - clouding of the eye's lens - Cataracts  develop at an earlier
                                 age in people with diabetes. (also called “MOTYA” in
                                 Gujarati)                                                        

§         Glaucoma                     - increase in fluid pressure inside the eye that leads to optic
                                 nerve damage and loss of vision. A person with diabetes is

                                          nearly twice as likely to get glaucoma (eye nerve damage  
                                          because of high eye pressure) compared to other adults.                                      

Patients with diabetes are more likely to develop eye problems such as cataracts and glaucoma, but the disease’s affect on the retina is the main threat to vision.  Most patients develop severe diabetic changes in the retina after approximately 20 years.  The effect of diabetes on the retina is called diabetic retinopathy. 

How does Diabetes affect the retina?

Diabetes affects the circulatory system of the retina. The blood vessels become fragile, leak blood, fat and body fluid. This can cause swelling of the most sensitive part of the retina, the macula, called Macular edema which if not treated on time causes irreversible loss of vision. Macular edema is the commonest cause of loss of vision in diabetics.

With time blood vessels shut down and retina becomes deprived of oxygen or ischemic.   New vessels develop as the circulatory system attempts to maintain adequate oxygen levels within the retina.    Unfortunately, these delicate vessels are very fragile and bleed easily.  Blood may leak into the retina and vitreous, causing spots or floaters, along with sudden loss of vision. 

In the later phases of the disease, continued abnormal vessel growth and scar tissue may cause serious problems such as retinal detachment and glaucoma.  Treating such cases is many a times impossible.

Signs and Symptoms

The affect of diabetic retinopathy on vision varies widely, depending on the stage of the disease.  Some common symptoms of diabetic retinopathy are listed below; however, diabetes may cause other eye symptoms.

·         Blurred vision (this is often linked to blood sugar levels)

·         Floaters and flashes

·         Distorted vision

·         Double vision

·         Sudden loss of vision 

Detection and Diagnosis

Diabetic patients require routine eye examinations by an eye care expert well trained in examining diabetic patients.

The first examination should be SOON after one is diagnosed to have Diabetes and there after the examining practitioner will suggest the schedule accordingly but NOT LESS than once a year.

The diagnosis of diabetic retinopathy is made following a detailed examination of the retina with an ophthalmoscope. Some drops will be instilled in the eye (dilating drops) so that the retina can be examined in detail. Without dilatation retina cannot be examined properly and serious conditions can be easily missed out.

Its IMPORTANT to note that one could be having very serious retinal problem and yet have good vision till when it is too late. Many patients complain of sudden loss of vision having had very good vision previously.

Most patients with diabetic retinopathy are referred to vitreo-retinal surgeons who specialize in treating this disease. 

Can diabetic retinopathy be prevented?

You can prevent vision loss due to diabetic retinopathy by keeping your blood sugar levels and blood pressure near normal. This can help lower your chance of developing damage to small blood vessels, which decreases the risk of damage to the retina.

Treatment

Diabetic retinopathy is treated in many ways depending on the stage of the disease and the specific problem that requires attention.  The retinal surgeon relies on several tests to monitor the progression of the disease and to make decisions for the appropriate treatment.  These include: fluorescein angiography, retinal photography, and ultrasound imaging of the eye. LASER treatment (photocoagulation) is usually very effective in preventing further vision loss if it is done before the retina has been severely damaged, however, it will not return what is already lost. Surgical removal of the vitreous gel (vitrectomy) may also help improve vision if the retina has not been severely damaged. At this time, there is no cure for diabetic retinopathy.

LASER facilities for treating diabetic retinopathy are available in Tanzania and Kenya and surgical expertise is available only in Tanzania within the East, Central and Southern African regions.

Prevention

Researchers have found that diabetic patients who are able to maintain appropriate blood sugar levels have fewer eye problems than those with poor control.  Diet and exercise play important roles in the overall health of those with diabetes hand in hand with regular eye check up and timely LASER intervention.

Take home message for Diabetic patients:

YOU MUST SEE AN EYE CARE EXPERT AT LEAST ONCE A YEAR FOR DETAILED RETINAL EXAMINATION.

“Community’s health – CHB’s priority”