New eye test is early detector of diabetes

Excerpted from page 52 of the January/February 2017 edition of AOA Focus.

The eyes are the window to the soul, and possibly a view to overall health and longevity, according to a recent study published in the journal Diabesity. Using new imaging technology, doctors are able to see tiny incidents of damage to the retina, known as sub-clinical retinal micro-aneurysms.

The researchers behind this new study have found a relationship between these micro-aneurysms and insulin resistance, one of the first nefarious steps on the road to Type-II diabetes.

"Not only does insulin resistance negatively impact eye health, but it also causes cardiovascular disease, cancer, stroke and all the sequela that diabetes causes," says Kerry Gelb, O.D., who practices in New Jersey and is the study's principal researcher. "It is related to the leading causes of mortality and morbidity."  

Dr. Gelb and his colleagues examined the retinas of 30 subjects using the RHA Instrument manufactured by Annidis Corporation. The RHA uses different wavelengths of light to make the layers of the retina more visible. The 580 nanometer yellow channel is absorbed by the yellow hemoglobin in the blood vessels in the retina, delivering an incredible picture of the vascular health of the retina, and making the micro-aneurysms appear as small bulges in the blood vessels. (Dr. Gelb has no connection to Annidis Corp.)

A series of blood tests designed to gauge the presence and severity of insulin resistance were then administered to the subjects, and the correlation between insulin resistance and the presence of micro-aneurysms became clear.  

Changing lifestyles, saving lives

According to the Centers for Disease Control and Prevention, more than 29 million Americans suffer from diabetes and 25% of them do not know they have the disease. More than one-third of adults—about 86 million people—have pre-diabetes, but approximately 90% of them are unaware of the condition.

Insulin resistance is the first trickle in a cascade of symptoms that are collectively known as Metabolic Syndrome, which is a precursor to pre-diabetes and drastically raises the risk not only of diabetes, but also heart disease, cancer and stroke. Therefore, early detection through the use of the RHA has the potential to save lives, not to mention billions of dollars, in health resources.  

Dr. Gelb likes to quote an academic colleague of his, who says, "The OD is the new GP." In fact, he or she often is the very first health practitioner to introduce the subject of insulin resistance to his or her patients. Several times a day, the doctor of optometry will find himself or herself preaching the virtues of diet and exercise.

"We are talking early prevention. There are no drugs at this point. It is all lifestyle change," he says. "Once people have bleeding in their eye, either from macular degeneration or diabetic retinopathy, we are near the end. Once blood vessels start bleeding, to a point where a diabetic heart disease patient needs a vitrectomy, 50% of patients don't live another four years. The idea is that you catch them early and give them the information they need. I can't tell you how many patients have said, 'I wish my general doctor would have talked about this.'"  

Read more about optometry's role in diabetes care on page 26 of the November/December 2016 edition of AOA Focus.