Global diabetes epidemic must not become epidemic of blindness
Systematic eye screening, preventive treatment can have far-reaching impact
The global epidemic in type 2 diabetes mellitus is of unprecedented proportions. In absolute numbers, it probably exceeds any previous epidemic in the history of mankind. There are now more than 400 million people with diabetes in the world, and the number is projected to exceed 600 million by 2030.
In 2000, there were “only” 150 million people in the world with diabetes. In China alone, there are now more diabetic patients than were in the world when diabetic eye screening and preventive care for diabetic eye disease started in the 1980s.
During 20 years with type 2 diabetes, roughly 66% of patients develop retinopathy and about 33% develop sight-threatening retinopathy, where treatment is needed to prevent vision loss. Thus, we may expect that one-third of the more than 400 million people currently with diabetes will develop diabetic macular oedema or proliferative diabetic retinopathy within the next 20 years.
Systematic screening for eye disease in diabetic patients started in northern Europe in the 1980s, with dramatic lowering of diabetic blindness, for example, in Iceland. In the UK, systematic screening over the past 2 decades has demoted diabetes from being the most frequent cause of blindness in the working-age population.
A global effort to prevent an epidemic of diabetic blindness must be based on the proven success of systematic eye screening and preventive treatment. This is a huge task.
Presently, systematic screening for diabetic eye disease is regularly undertaken in a few northern European countries and sporadically by some eye clinics and regions elsewhere.
Most diabetic patients around the world do not have access to diabetic eye screening. The cost is considerable. Each screening visit in European settings costs €30 to €50. If this number is multiplied by 400 million, we are soon talking about real money.
Technologic developments can help economise this process. Risk stratification can help focus resources toward those at greatest risk and reduce the overall costs of screening programs by 50%.
Automatic analysis of fundus photographs is progressing rapidly and novel automatic approaches are on the horizon, including measuring diabetic retinopathy severity with oximetry analysis of fundus photographs.
Telemedicine can help extend the reach of diabetic eye screening, and improving technology in fundus photography and rapidly lowering cost of such instrumentation all make global diabetic eye screening more affordable.
While global diabetic eye screening is a considerable task, the cost of doing nothing is much greater.