Diabetic retinopathy is one of the leading causes of blindness in people of working age. The total number of people with diabetes is projected to rise to 439 million cases around the world in 2030.
Diabetic retinopathy is responsible for 1.8 million of the 37 million cases of blindness all over the world, according to Dr Bipul Kumar Das, Associate Consultant Ophthalmologist, KG Hospital.
He pointed this out while making a power-point presentation on “Diabetic retinopathy” for the benefit of the Post Graduate medical students at KG Hospital Auditorium recently.
Fifth major cause
Quoting the World Health Organization statistics, Dr Bipul Kumar Das said that diabetic retinopathy happened to be the fifth major caus
e of global blindness, next to cataract, glaucoma, Age-related macular degeneration, and corneal opacity.
He said that the best predictor of diabetic retinopathy was the duration of the disease. After 20 years of diabetes, nearly 99% of patients with Type 1 diabetes and 60% with Type 2 diabetes had some degree of diabetic retinopathy. 33% of patients with diabetes had signs of diabetic retinopathy.
People with diabetes were 25 times more likely to become blind than the general population. Defining the terms “diabetic retinopathy,” Dr Bipul Kumar Das said that it was a progressive dysfunction of the retinal blood vessels caused by chronic hyperglycemia.
Initially, diabetic retinopathy would be asymptomatic and if not treated, it could cause low vision and blindness. As for retina, he said that the “retina is a multilayered, light sensitive neural tissue lining the inner eye ball.
“Light is focused onto the retina and then transmitted to the brain through the optic nerve. The macula is a highly sensitive area in the centre of the retina, responsible for central vision. The macula is needed for reading, recognizing faces and executing other activities that require fine, sharp vision,” Dr Bipul Kumar Das said.
Diabetic retinopathy is asymptomatic in early stages of the disease. As the disease progresses symptoms may include:
- Blurred vision
- Fluctuating vision
- Distorted vision
- Dark areas in the vision
- Poor night vision
- Impaired colour vision
- Partial or total loss of vision
Diabetic retinopathy is a microvasculopathy that causes: retinal capillary occlusion and retinal capillary leakage.
Microvascular occlusion is caused by: thickening of capillary basement membranes; abnormal proliferation of capillary endothelium; increased platelet adhesion; increased blood viscosity and defective fibrinolysis.
Microvascular leakage is caused by: impairment of endothelial tight junctions; loss of pericytes, weakening of capillary walls and elevated levels of vascular endothelial growth factor.
Dr Bipul Kumar Das noted that “diabetic retinopathy is preventable through strict glycemic control and annual dilated eye examination by an ophthalmologist.”