Around 537 million people worldwide are living with diabetes. For millions of them, the cruellest complication is watching their vision slowly disappear. Now, for the first time, scientists have identified the specific protein that triggers the earliest damage to the eye — and shown that blocking it prevents the disease from taking hold.
Researchers have pinpointed a protein called **LRG1** (leucine-rich alpha-2 glycoprotein 1) as the key trigger of diabetic retinopathy — a condition that damages the blood vessels of the retina and is the leading cause of preventable blindness worldwide. When scientists blocked LRG1 in diabetic mice, the retinal damage that normally follows diabetes did not occur.
**The Scale of the Problem**
Diabetic retinopathy affects an estimated 9 million people in the US alone, and tens of millions globally. It develops when high blood sugar damages the tiny blood vessels at the back of the eye over years or decades. Current treatments — laser therapy, injections, surgery — focus on halting damage that has already begun. What's been missing is a way to stop the damage before it starts.
**What LRG1 Does**
LRG1 is a protein that circulates in the blood. In healthy eyes, it's present at low levels. But in people with diabetes, elevated blood sugar causes LRG1 levels to rise — and this excess LRG1 interferes with a signalling pathway that normally keeps retinal blood vessels stable and healthy. When disrupted, the vessels become vulnerable to the damage that, over time, leads to retinopathy.
In the study, diabetic mice treated to block LRG1 showed significantly reduced retinal vessel damage compared to untreated animals. The prevention was not partial — in the experimental models, the earliest signs of retinopathy were effectively stopped.
**What Comes Next**
The research opens a new front: *prevention*, rather than damage control. If a drug can be developed to safely block LRG1 in humans — likely as an eye drop or injection given early to high-risk patients — it could prevent retinopathy from developing in the first place. That's a fundamentally different ambition from anything currently available.
For 537 million people with diabetes — a number that continues to grow — protecting the eyes is not just a medical goal. It's about being able to see your grandchildren. 👁️
*Sources: Science Daily, March 2026 · University College London Eye Institute*