London: More than two-thirds of the increase in blindness and visual impairment globally in the past two decades has been caused by diabetes, finds a recent study.
Diabetic retinopathy is a condition resulting from chronically high blood sugar, in which the delicate blood vessels in the lining of the inside of the eye (retina) get damaged and start leaking thus distorting vision, according to the US-based National Eye Institute research organisation.
"With the alarming prevalence of vision loss due to diabetes rising more than two-thirds in the last 20 years, the precipitous global epidemic of diabetes must be addressed," said lead researcher Rupert R.A. Bourne, Ophthalmologist and Professor at the Anglia Ruskin University in Britain.
The findings revealed that one in every 39 blind people suffered vision loss due to diabetic retinopathy in 2010 -- a marked increased of 27 per cent since 1990.
Of those with moderate or severe vision impairment, one in 52 people had blindness attributed to diabetes, an alarming increase of 64 per cent since 1990.
Further, the researchers found that during the last 20 years, South Asia, Middle East, North Africa, and West Sub-Saharan African countries showed the highest number of people visually impaired because of diabetic retinopathy.
East Asia, Tropical Latin America, and South Sub-Saharan Africa were the regions with the highest number of people who were rendered blind from diabetic retinopathy.
South Sub-Saharan Africa, Southern Latin America Central Sub-Saharan Africa showed the greatest increase in the prevalence of blindness caused by diabetic retinopathy, in people older than 50.
As more people live longer with diabetes, there is a higher risk of developing diabetic retinopathy, and subsequent vision loss.
Poor control of glucose levels and lack of access to eye health services in many parts of the world are thought to contribute to this increase, the researchers said, in the paper published in the journal Diabetes Care.
In diabetic retinopathy's most advanced stage, new abnormal blood vessels grow, damaging the retina and leading to permanent scarring and vision impairment or blindness.
"Unfortunately diabetic retinopathy usually does not have any symptoms in the early stages," added Janet Leasher, Professor at the Nova Southeastern University (NSU) in Florida, US.
People diagnosed with diabetes should undergo a dilated eye health exam at least every year.
Patients should also work closely with their health care providers to determine the best methods to control their blood sugar and blood pressure levels, the researchers suggested.