Retinopathy in Diabetes

Diabetic retinopathy is the most frequent cause of new cases of blindness among adults aged 20-74 years. During the first two decades of disease, nearly all patients with Type 1 diabetes and more than 60% of patients with Type 2 diabetes have retinopathy.

Diabetic retinopathy progresses in four stages:

1. Mild Nonproliferative Diabetic Retinopathy (NPDR): Characterized by increased vascular permeability. (At this earliest stage, microaneurysms occur.)
2. Moderate Nonproliferative Diabetic Retinopathy (NPDR): Characterized by few vascular closures.
3. Severe Nonproliferative Diabetic Retinopathy (NPDR): Characterized by many more blood vessel closures.
4. Proliferative Diabetic Retinopathy (PDR): Characterized by the growth of new blood vessels on the retina and posterior surface of the vitreous. These new blood vessels are abnormal and fragile. By themselves, these blood vessels do not cause symptoms or vision loss.

However, blood vessels damaged from diabetic retinopathy can cause vision loss in several ways:

• Central vision may be impaired by macular edema or capillary non-perfusion.
• New blood vessels of PDR and contraction of the accompanying fibrous tissue can distort the retina and lead to tractional retinal detachment, producing severe and often irreversible vision loss.
• New blood vessels may bleed, adding the further complication of pre-retinal or vitreous hemorrhage.
• Neovascular glaucoma associated with PDR can be a cause of visual loss.

To reduce the risk of vision loss, the following steps are recommended with treatment modalities:

1. Patients with Type 1 diabetes should have an initial dilated and comprehensive eye examination by an ophthalmologist within 3-5 years after the onset of diabetes.
2. Patients with Type 2 diabetes should have an initial dilated and comprehensive eye examination by an ophthalmologist or optometrist shortly after diabetes diagnosis.
3. Subsequently, annual examinations by an ophthalmologist or optometrist should be repeated for both Type 1 and Type 2 diabetic patients.

Higher Studies have established that treatment modalities to control glycemia & blood pressure could prevent & delay the progression of diabetic retinopathy as well as prevent loss of vision in a larger proportion of patients with diabetes.

01 Feb 2010