Proliferative Diabetic Retinopathy and Diabetic Macular Edema
Diabetes may cause serious eye disorders
Nearly 415 million people in the world have diabetes(1), a chronic condition that affects the function of insulin, a hormone that regulates blood sugar. Diabetics are at an increased risk of developing serious eye conditions, including diabetic retinopathy (DR). Diabetic retinopathy is a very common complication of diabetes and a leading cause of vision loss in adults. Loss of vision from diabetic retinopathy is often characterized by blurred central vision with some dark patches. Diabetic retinopathy is a progressive condition that can be broadly classified into: non-proliferative and proliferative diabetic retinopathy, depending on the progression of the disease. Diabetic macular edema (DME) is a manifestation of non-proliferative diabetic retinopathy and can develop at any stage of diabetic retinopathy. Proliferative Diabetic Retinopathy (PDR) occurs when chronic retinal hypoxia causes proliferation of new, fragile vessels that tend to leak fluid and blood. This is the most advanced stage of diabetic eye disease and can result in permanent vision loss. PDR affects over 19 million people worldwide today, and this number is expected to grow to almost 22 million by 2020(2).
Prevalence is high, and there is no cure
The most important risk factors for DR are increased blood sugar levels, raised blood pressure, and longer duration of diabetes. All people with Type 1 or Type 2 diabetes are at risk for DR and DME. The risk of developing DR or DME increases significantly the longer a person has diabetes. The American Academy of Ophthalmology estimates that nearly 80% of patients with Type 1 diabetes will have developed DR after living with diabetes for 15 years. Early treatment of DR or DME can slow the progression of the disease, but there are currently no treatments that can reverse advanced vision loss.
Disease pathogenesis
Diabetic retinopathy is the second most common retinal disease. It occurs in patients with either Type 1 or the Type 2 diabetes as a result of chronically elevated blood glucose levels. DR is a progressive condition in which there is damage to the tiny blood vessels, or capillaries, of the retina; this vascular damage results in a chronic decrease in oxygen supply to retinal cells. DME is caused by leaky blood vessels in the retina that result in blurred vision, loss of contrast, and overall vision loss, and is the most common cause of vision loss in diabetic patients.
(1) IDF Diabetes Atlas. 7th ed. Brussels: International Diabetes Federation; 2015.
(2) Market Scope, The Global Retinal Pharmaceuticals & Biologic Market, 2015.