20% diabetics suffer eye disease

Diabetic Retinopathy (DR) is the most common diabetic eye disease that affects blood vessels of the retina. DR is usually bilateral, which means it affects both eyes. People who have it often don't notice changes in their vision in early stages. But as it progresses, DR usually causes vision loss and in many cases, it cannot be reversed.

Since DR can likely affect those who suffer from diabetes, it is of socioeconomic concern as it can lead to severe vision loss in the working age group. India is estimated to have over 41 million diabetics, with the prevalence of DR in about 20 per cent of the people with diabetes.

The risk factors for DR are impacted by the age of diagnosis of diabetes, duration of diabetes, insulin dependency, poor metabolic control, high blood pressure, pregnancy, renal disease and smoking.

There are two types of DR: proliferative and non-proliferative. Non-Proliferative Diabetic Retinopathy (NPDR) is the earliest stage of diabetic retinopathy. In this condition, damaged blood vessels in the retina begin to leak extra fluid and small amounts of blood go into the eye. Sometimes, deposits of cholesterol or other fats from the blood may leak into the retina. Many people with diabetes may have mild NPDR, which may not usually affect their vision.

Proliferative Diabetic Retinopathy (PDR) occurs when the blood vessels in the retina close, preventing enough blood flow. The retina responds to this condition by growing new blood vessels (called neovascularisation), but these new blood vessels are abnormal and often accompanied by scar tissue. They do not supply the retina with proper blood flow, and may cause the retina to wrinkle or detach. Hence PDR may cause more severe vision loss than NPDR because it affects both central and peripheral vision.

Treatment options

Current treatment options available for Diabetic Retinopathy include:

• Good glycemic control in those with mild or moderate DR. The best treatment for diabetic retinopathy is to prevent it. Strict control of blood sugar will significantly reduce the long-term risks of vision loss.
• Laser photocoagulation for Sight Threatening Diabetic Retinopathy (Proliferative DR and clinically significant macular edema).
• Vitreous surgery to treat complications of Proliferative DR such as non-clearing vitreous hemorrhage, tractional/combined retinal detachment.

Currently, drugs like Ruboxitaurine (Protein kinase inhibitors) are under clinical trials for prevention of sight threatening DR. Lipid lowering drugs such as statins have also found to be useful in reducing the incidence of diabetic retinopathy.