Over 100 million people in the U.S. are affected by diabetic retinopathy, a complication of diabetes that affects the eyes.\u00a0<\/p>\n
The condition is caused by damage to the blood vessels in the retina, the light sensitive tissue at the back of the eye.\u00a0<\/p>\n
At first, diabetic retinopathy might not cause any symptoms, or the problems might be mild.\u00a0<\/p>\n
However, if the underlying diabetes remains poorly managed, it can lead to blindness.\u00a0<\/p>\n
In a new study, University of Michigan researchers showed that treatment with the molecule norrin can prevent vision loss in diabetic rats.\u00a0<\/p>\n
Diabetic retinopathy treatment\u00a0<\/p>\n
Current therapies for diabetic retinopathy target vascular endothelial growth factor<\/a>, or VEGF, a protein that causes new blood vessels to form.\u00a0<\/p>\n VEGF also increases blood vessel permeability or the capacity to allow water and nutrients to move in and out of the bloodstream into tissues.\u00a0<\/p>\n In patients with diabetic retinopathy, excess VEGF causes the growth of abnormal, leaky blood vessels, both leading to vision loss.\u00a0<\/p>\n Although anti-VEGF agents are commonly used to treat diabetic retinopathy, it requires several injections and fails to fully manage half the treated patients.\u00a0<\/p>\n “There is an urgent need for new therapies that can help preserve vision in patients with diabetic retinopathy,” said David Antonetti, Ph.D., Roger W Kittendorf Research Professor of Ophthalmology and Visual Sciences at Kellogg Eye Center.\u00a0<\/p>\n “We have been working on the effects of norrin for several years and these results will help develop new therapies that can prevent vision loss.”\u00a0<\/p>\n Preventing vision loss\u00a0<\/p>\n In previous studies, the team showed that norrin can reverse the effects of VEGF on the blood vessel barrier in cells.\u00a0<\/p>\n In the current study, they found that after rats developed diabetes, their levels of norrin decreased and this was accompanied by decreased vision.\u00a0<\/p>\n When they injected these rats with norrin, the researchers could prevent vision loss.\u00a0<\/p>\n “We are excited that norrin treatment can also reduce the loss of nerve cells involved in vision in diabetic rats,” said Laura Gonz\u00e1lez-Gonz\u00e1lez, Postdoctoral Fellow in the Antonetti lab.\u00a0<\/p>\n Treatment with norrin also prevented retinal cell death and inflammation<\/a>, both in early and late stages of diabetes.\u00a0<\/p>\n Starting norrin treatment even after vision loss prevented further loss in the diabetic rats.\u00a0These results suggest that norrin can potentially help prevent vision loss in patients with diabetes.\u00a0<\/p>\n The team identified several genes that were affected by norrin treatment, and they are working on understanding how they contribute to barrier restoration.\u00a0<\/p>\n Clinical trials and retinal blood vessels\u00a0<\/p>\n The work done by the Antonetti lab has helped target identification for a new diabetic retinopathy treatment method.\u00a0<\/p>\n To this end, their work helped EyeBio and Merck develop clinical trials for drugs that can increase the activity of cell receptors that respond to norrin.\u00a0<\/p>\n Antonetti was also involved in helping Merck develop a drug for treating adults with macular edema, a major driver of vision loss in patients with diabetic retinopathy.\u00a0<\/p>\n If successful, this will be the first new therapy for the condition in 16 years.\u00a0<\/p>\n Source:<\/p>\n Michigan Medicine- University of Michigan\u00a0<\/a><\/p>\n Journal reference:<\/p>\n