Jerusalem — One of the most worrisome complications of Type I and Type II diabetes is damage to the eyes.
The first culprit is diabetic retinopathy, where small blood vessels leak, causing the tissue in the retina — the light-sensitive lining at the back of the eye — to swell, impairing vision. Making matters worse, the growth of new blood vessels causes scar tissue to form.
It is the leading cause of new blindness in people aged 20 to 74.
Diabetics are also prone to developing cataracts, the clouding of the eye’s lens, at an earlier age and in higher percentages than people who don’t have diabetes.
Israel, where Jews and especially Arabs have a relatively high rate of diabetes, is at the cutting edge of diabetes-related research.
A team of researchers from the medical faculties of the Rambam Medical Center and the Technion that included Drs. Naim Shehadeh, Elias Andrawus, Ido Perlman and others set out to determine if light is a significant factor in diabetic retinopathy, cataracts or both.
After completing their research with diabetic animal models, Shehadeh and Perlman developed a unique optic filter that blocks light’s most harmful high-energy wavelengths and contributes to the reduction of damage to the retina and the prevention of cataracts.
Human clinical trials will begin later this year to confirm that the filters work just as well in humans.
Even without this confirmation, both the researchers and the Israel Diabetes Association believe that if there is a potential to save diabetics’ eyesight, “using the filters will do no harm and could be beneficial,” Shehadeh told The Jewish Week.
Israeli consumers will be able to obtain prescription and non-prescription sunglasses fitted with the optic filter by the beginning of April. The team’s next goal is to create non-colored filters so they can be used with regular eyeglasses.
The aim of the five-year study was to evaluate the effect of filtering certain harmful light wavelengths (under 530 nanometers) on the development of ocular damage and cataracts in diabetic rats, Shahedeh said.
“Our main question was, why is the eye so vulnerable in patients with diabetes? We believed that it is not just high blood glucose levels that triggers damage in the retina. It also had to be something connected to sunlight and wavelengths.”
Shahedeh said the team felt an urgency while doing its research: “We have nothing to offer diabetic patients” already suffering from eye damage. “All we can do is tell them to try to control their blood glucose. At least when it comes to preventing and reducing renal damage from diabetes, there are some treatments available.”
The Rambam-Technion experiment utilized diabetic rats who were exposed to a wide spectrum of light wavelengths using different optic filters. Then the rats were examined by a vision expert several times, to determine whether their eyes had sustained damage.
According to the team’s latest published paper, attenuating bright white light with a special optic filter can significantly protect the eyes of diabetic rats. The brown filter was more effective than the yellow filter, which transmitted more light in the short- and medium-wavelength range of the spectrum, causing more severe retinal damage.
The experiment showed that the development of cataracts in diabetic rats was mainly due to hyperglycemia, but that light irradiance exacerbated the condition.
If the human clinical trial finds the optic filters effective, “the potential for use is great,” Shehadeh said. “They could be used in building and car windows, for example.”
Another Israeli product in the pipeline could help Type II diabetics postpone the need for insulin needle pricks for several years.
The company Oramed, which is traded on the Nasdaq, had created an oral delivery system for insulin that could be available to patients within four to five years, pending FDA approval, according to Nadav Kidron, Oramed’s CEO.
“We’re at a very late stage of clinical trials,” Kidron said. “The coming trial, which will begin within a couple of months, will give us an exact measurement of the drug’s efficacy.”
The trial will involve roughly 240 Type II patients in the U.S. who are not yet dependent on injectable insulin, who will take the oral insulin for a 90-day period.
“We have developed the technology to take these injections and deliver them orally.
Insulin is a peptide and until now it has been impossible to deliver peptides orally because they would degrade in the mouth and stomach. Oramed has developed a kind of shield for insulin that protects it from enzymes that would break it down, and a coated capsule that allows the insulin to move intact through the body. There are also absorption enhancers to help it go through the intestine wall to the liver, the major organ that makes and stores glucose and regulates the secretion of insulin into the bloodstream.
“Unlike an injection that goes directly into the bloodstream, the oral delivery is able to mimic the physiological way the body works to allow insulin to act directly on the liver to take control of blood sugar,” Kidron said.
When patients with Type II diabetes are first diagnosed, “the advice is usually to start with diet and exercise and non-insulin medications,” Kidron noted. “What we want to do is offer an early insulin treatment to stave off the need for injectable insulin by several years.”
During the last clinical trial in the U.S., he said, the group that received the oral insulin and not the placebo saw a “statistically significant difference” in its blood glucose levels.
The potential market for orally delivered insulin and eventually other orally delivered injectables “is huge,” Kidron said.
“Last year the world spent $600 billion on diabetes. People want to be on a healthier track that helps them better control their diabetes.” ◆