A newly identified protein that sparks the earliest stages of diabetic retinopathy could transform how the sight-threatening condition is treated, according to new research from University College London (UCL).
In findings released by Diabetes UK, researchers report that a protein called LRG1 plays a critical role in kickstarting retinal damage soon after diabetes develops – long before symptoms appear and before current treatments are typically used.
Led by Dr Giulia De Rossi, the study shows that LRG1 causes the cells surrounding the eye’s tiniest blood vessels to contract too tightly, effectively “squeezing” the vessels and cutting off vital oxygen supply to the retina. This oxygen deprivation sets off a cascade of changes that can eventually lead to vision loss.
Crucially, when LRG1 was blocked in diabetic mouse models, researchers were able to prevent this early injury and maintain healthy retinal function.
“Our discovery shows that diabetic eye disease starts earlier than we thought, and LRG1 is a key culprit in this early damage,” said Dr De Rossi, a senior research fellow at the UCL Institute of Ophthalmology and a Diabetes UK and Moorfields Eye Charity RD Lawerence Fellow.
“Targeting this protein could give us a way to protect vision before serious damage occurs and prevent, rather than treat, blindness in millions of people living with diabetes.
A shift from treatment to prevention
Diabetic retinopathy occurs when consistently high blood sugar damages retinal blood vessels. While regular eye screening can detect early signs, effective treatments are generally only available once symptoms – such as blurred or distorted vision – have already emerged.
Current therapies focus on blocking VEGF, another protein involved in abnormal blood vessel growth. But these treatments typically begin at later stages, help only around half of patients, and rarely reverse existing damage.
The UCL findings suggest LRG1 becomes active far earlier than VEGF, positioning it as a promising new therapeutic target – one that could stop disease progression before vision deteriorates.
Researchers at UCL have already developed an LRG1-blocking drug and are completing final laboratory studies ahead of planned clinical trials.
They believe the therapy could benefit patients across all stages of retinopathy, including those who fail to respond to existing anti-VEGF injections.
Dr Faye Riley, research communications lead at Diabetes UK, said the discovery represents a major advance:
“Nearly a third of adults with diabetes have some signs of retinopathy, and it is one of the most feared complications of the condition. By identifying the root cause of early damage, and offering a new path for treatment, this research holds immense promise for protecting the sight of people with diabetes worldwide.”
The study was co-funded by Diabetes UK and Moorfields Eye Charity, with support from Wellcome.
The results were published in Science Translational Medicine.
