This article appeared in the March 14 issue of the Taubman Institute (TI) E-News.
Dr. Tom Gardner—Taubman Scholar and Kellogg physician—seeks to heal diabetes-related loss of vision
Clinical trial will assess the effect of laser treatments and whether retinal tissue can be revitalized after treatment
Dr. Tom Gardner
Predicting who might experience diabetes-related eye damage, and finding ways to intervene sooner to avoid vision loss, is the mission of Taubman Scholar Dr. Thomas Gardner.
He's currently enrolling patients in a clinical trial designed to assess the effect of common treatments and whether or not retinal tissue can be revitalized.
According to the Centers for Disease Control and Prevention, some 4 million American adults have some level of diabetic retinopathy, including about one-third of diabetes patients over the age of 40. It's the leading cause of legal blindness in people age 20 to 74.
Currently, laser treatment and intraocular injections are the available therapies for diabetic retinopathy – usually given to those who have lost vision, or who don't see well at night. The problem is that the beam of the laser kills tissue inside the eye, to stop the progressive leaking of blood vessels that leads to retinopathy.
"Laser treatment is the ocular equivalent of an amputation," said Dr. Gardner, who was named the Healthy Eyes Taubman Scholar in 2012. His three-year Taubman Institute grant is sponsored in part by JDRF, the charitable organization that funds research to better treat type 1 diabetes.
Laser intervention preserves the central vision, but conventional thinking is that the tissue zapped by the device is gone for good.
That may not be the case, said Dr. Gardner, who serves at U-M's Kellogg Eye Center as Professor of Ophthalmology, Visual Sciences and Molecular & Integrative Physiology. Gene therapy tried in people with hereditary blindness has had some interesting effects, leading scientists to believe "dead" areas of the retina might possibly be revived in diabetes patients, too.
"Maybe there is more capacity in there than we think, and the activity is just turned down," said Dr. Gardner. "We're looking for ways to juice up the activity of the retina."
His current clinical study analyzes the eyes of people who have "maxed out" on laser treatments, testing the effects of the laser on the structure of the retina, "because we really don't know what the treatment is doing to them," Dr. Gardner said. About 30 laser-treated patients will be followed for a two-year period. The tests will provide detailed information about the impact of diabetes and laser treatment on the retina and about what parts of the retina remain viable.
Meanwhile, in the lab, Dr. Gardner's team is testing the effects of insulin-like growth factor 2 (IGF-2), a human protein, on the retina. The ultimate aim: to come up with a compound that can keep retinal cells alive and stimulate them to provide clearer vision.
It's the sort of high-risk, high-reward research the Taubman Institute was founded to encourage. And Taubman/JDRF funding has given a jumpstart to this line of research and more, Dr. Gardner said. The grant also is being used to support research into type 1 diabetes patients with no symptoms yet, because early stages of retinopathy are little-studied. And it's allowed for the purchase of a machine to gauge retinal function in type 2 diabetes patients at U-M, in a collaboration with other diabetes researchers.
"This gift is amplified so many times," said Dr. Gardner. "It not only made it possible for us to plan this study, but everything else builds upon it. It puts people together, and then things happen."