7 June 2017
Scientists supported by Diabetes UK have found a molecule that could be used as a new treatment for retinopathy in the future.
The molecule acts by reducing the leakage of small blood vessels at the back of the eye.
Retinopathy is a complication of diabetes which arises when blood vessels at the back of the eye become blocked, leaky or grow uncontrollably, damaging the light-sensing part of the eye, called the retina.
Effect on the eye
The researchers tested the effects of a molecule called VEGF-A165b on cells grown in the lab and blood vessels in the eye of a laboratory model of diabetes. The molecule was able to reduce the leakage of blood vessels and stop them growing uncontrollably.
Since VEGF-A165b is naturally found in our bodies, scientists hope they can find a way to increase its production in humans, to protect people with diabetes from developing eye damage.
It’s all about balance
Our bodies make two forms of the VGEF molecule, called VEGF-A165a and VEGF-A165b. The -165a form is thought to promote blood vessel leakage and uncontrollable growth, while the -165b form seems to have the opposite effect.
Levels of the -165a form are higher in diabetes and retinopathy, and an imbalance between the two forms may contribute to eye damage in diabetes.
How does retinopathy develop?
The retina is the light-sensitive layer of cells at the back of your eye. It catches the light and sends that information to the brain. A delicate network of blood vessels supplies the retina with blood and nutrients.
High blood pressure and high glucose levels can damage these small blood vessels, causing them to leak and grow uncontrollably. This can damage the retina, and if left untreated, retinopathy may lead to blindness.
The scientists tested the activity of VEGF-A165b in retina cells grown in the laboratory, where they looked at whether adding VEGF-A165b could prevent the damage caused by VEGF-A165a and high glucose levels.
They also studied rats with symptoms of retinopathy, counting the number of blood vessels at the back of the eye with and without VEGF-A165b treatment, and assessing blood vessel leakiness with a special dye.