Your role in treating diabetic patients: annual fundus exams, counseling

Issue: October 1998

BySusan E. Marren, OD FAAO

PHILADELPHIA - Health food stores and many grocery stores have aisle after aisle of nutritional supplements with labels that make such sweeping claims one wonders why people need a medical doctor at all. Unfortunately, these items may be attractive to diabetics.

"Many of these items marketed for people with diabetes have inconsistent or negligible amounts of active ingredients in them, and some may even contain toxins," said Peggy Schiavo, MS, RD, CDE, clinical dietitian at Pennsylvania Hospital here.

"Patients with diabetes and hypertension are always looking for something that will decrease the number of sticks, pills, visits to the doctor or amount of money paid," said Kari Blaho, PhD, of Memphis, Tenn.

"None of these health food store items or vitamins has ever been shown to enhance glucose control," Dr. Blaho continued. "Without regulation by the Food and Drug Administration, we have to be concerned that what's in the bottle may not necessarily be what's on the label. People tend to think if it's natural, they can take more than the recommended amount. And vitamins do have risk for (drug) interactions."

Chromium for diabetics?

"Chromium is a mineral supplement that has been bandied about," Ms. Schiavo said. "If you have a chromium deficiency your glucose tolerance will suffer, but it doesn't hold true that more chromium enhances glucose tolerance if you are not deficient. At this point, I'm not recommending it because you're unlikely to be deficient in chromium if you're eating a balanced diet." Chromium is found in oils and grains, she said.

"In the absence of frank deficiency, none of these nutritional supplements has a role in treating anything," Dr. Blaho added. "The research does not yet support blanket recommendations for chromium, and without knowing the status of the patient, adding chromium could be unnecessary and possibly risky."

What are the downsides of suggesting supplements or even vitamins to diabetic patients? "There is no vitamin you can take that will improve your blood sugar," Ms. Schiavo said.

"There are some good pilot data that indicate some nutritional supplements may delay end organ damage associated with long-term wear and tear on physiology, but no good data to indicate that these supplements have any beneficial effect for diabetes," Dr. Blaho said. "But until we get the results of big, multicenter trials, we cannot make any conclusions."

Focus resources on medications

Even recommending an expensive multivitamin may be inappropriate because patients need their financial resources first and foremost for their prescribed medications. Compliance is difficult with multiple medications, and adding a vitamin could upset the balance or, worse, delude the patient into believing he or she could discontinue one of his or her medications or disregard the diet recommendations. "The patient may use his or her budgetary resources to buy the supplement and then find that he or she can't afford all of the regular medications," Dr. Blaho said.

The optometrist's role

"Good nutrition does make a difference in one's overall health, but we don't have any data that show it is good for treatment of diseases," Dr. Blaho continued. Good nutrition is more of a preventive measure, she said.

What can optometrists do for their diabetic patients? Ms. Schiavo said that, as doctors, we are in a position of authority. "Urge patients to get the care they need," she said.

If you suspect that your patients' struggle with blood sugar is directly related to their dietary control, and the primary care doctor appears to be overloaded, you might suggest that patients attend nutrition classes for diabetics at a hospital. "I'd recommend classes to any new diabetic or anyone interested in improving control," said Ms. Schiavo. "Even a doctor could never provide the hours of instruction that these classes offer."

Pennsylvania Hospital offers four classes on a continuing basis. "A podiatrist discusses foot health, a pharmacist discusses medications, a physical therapist talks about exercise and I talk about nutrition," Ms. Schiavo said. "Some people have come to our classes for years, more for the support group atmosphere provided."

New ADA recommendations

Even if patients have taken such classes in the past, dietary recommendations have changed since 1994. "It's so much better for patients to come back - after they're out of the hospital, when things are settled down - to attend the classes or speak to a dietician about a tailored meal plan," said Ms. Schiavo.

The new recommendations from the American Diabetes Association (ADA) have caused a tremendous change in the way patients manipulate their diet for sugar control. Rather than simply looking at sugars, patients are now taught to look for carbohydrates. The new recommendations make it easier to plan once-forbidden foods into a menu, using exchanges in a fashion similar to a Weight Watchers program.

"We're trying to have our patients learn to trade off one carbohydrate for another so they have a little more flexibility," Ms. Schiavo said. "For instance, if they want to have a piece of birthday cake at dinner, they can just skip the potatoes in the meal."

How about patients who eat what they like and simply adjust the insulin accordingly? It can be done, but it "does lead to weight gain, and the calories are still going to get absorbed. Patients can abuse that," she said.

Booklets are available through the ADA, which optometrists can order and dispense to patients.

Blood sugar and the A1C

Ms. Schiavo said that new legislation guidelines have made it easier for Medicare patients to monitor their own blood sugar at home with a glucometer.

"As of July, Medicare is covering some supplies," she said. "Now, for Medicare recipients, the price of the strips and lancets is not an obstacle. The downside is you still have to prick your finger. We're trying to raise awareness that this is what will give you the best feedback on how well your diet and medication are working. A blood sugar reading is just a snapshot of a moment. You can test at different times of the day so you get a good idea of how your blood sugar behaves throughout the day."

Ms. Schiavo added that the hemoglobin A1C laboratory test is the best indicator for the professional to accurately understand how the sugar control has been during the past 120 days. Blood sugar rises and falls continuously. It depends not only on food intake, but also on factors such as exercise, medication and stress.

A patient without hyperglycemia would have an A1C of about 5 to 5.5. A very tightly controlled diabetic would have about 6 or so. The mostly careful diabetic will run around 7 (indicating an average of blood sugar of 150).

Stephen H. Sinclair, MD, of Upland, Pa., is clinical professor of ophthalmology at Allegheny University and in private practice in retina at Crozer Chester Hospital. He was involved in the case of a patient who developed florid proliferative retinopathy in 1 year. The odds of going from nothing to proliferative retinopathy within 1 year would seem to be very small, but this patient's hemoglobin A1C, the measure of his glycosylated hemoglobin, was 12 to 13.

"For every 2% drop in the A1C from traditional control (Hg A1C 7 to 8) produces a 50% drop in the rate of complications. But what happens if you have a 2% rise with a Hg A1C of 12 to 13? This patient had a 20% to 30% chance of developing proliferative retinopathy from no retinopathy in 1 year," Dr. Sin clair said.

This patient also had hypertension, which aggravated the effect of diabetes on the target end organs such as the retina or kidneys. Other conditions - such as hyperlipidemia, anemia, smoking or vasculitis - that affect either the blood vessel or the oxygen-carrying ability of the blood within the vessel enhances their risk for developing retinopathy.

Cotton-wool infarcts are a signal that hypertension or one of these other conditions is aggravating the diabetes. Dr. Sinclair said that when he sees cotton-wool infarcts, he calls the primary care doctor and requests that blood pressure be measured in the supine position or after a step exercise test.

"Diabetics get hypertensive when they lie down or do mild exercise," Dr. Sinclair said. "A new recommendation for blood pressure for diabetics is 120/80 to 130/80 or less. When this is achieved, the rate of progression of retinopathy drops significantly."

Improving compliance and detection

Compliance with appointment recommendations is another key area for the eye care practitioner. Dr. Sinclair reports that between 35% and 50% of diabetics comply with the recommendation for annual dilated eye examinations (National Committee for Quality Assurance Statistics).

Why is it difficult to get patients with diabetes to come in for annual retinal screenings?

The answer is fourfold, according to Dr. Sinclair:

Fear of discovery. The patient is afraid something bad will be found.
Confrontation with the physician. They have been seeing doctors for many years and hearing horror stories: "If you don't control your sugar, you're going to go blind, you're going to lose your kidneys, you're going to lose your legs." Many diabetics avoid physicians as the years progress.
A very common reason is the time it takes away from work for appointments to see not only the eye doctor, but also other specialists.
Mixed signals. They hear from their family doctor: "If you manage your diabetes well, you won't get these bad things." The doctor may not actually say that, but that is what patients want to hear. The internist may say: "You're doing OK, but we've got to get the blood sugar a little lower." What patients hear is: "You're doing OK."

Centralized testing

Dr. Sinclair believes the answer to this is to centralize all testing for the diabetic in a walk-in facility. "At one site they put a fundus camera at the primary diabetic clinic, and they were able to get compliance with annual fundus exams up to about 85%," he said.

Dr. Sinclair was consulted about an ophthalmic imaging service that could be placed where the diabetic patient receives his or her primary care. He analyzed the situation for patient convenience and for physicians' cost containment. "You must use a digital fundus camera," he said. "Film is very expensive. With a digital system, although capital costs up front are steep, overall it is cheaper than film. Also, instead of sending the images off to be analyzed, with a digital system you use image processing on site to get immediate results."

Dr. Sinclair has developed a system that accurately detects hemorrhages and other lesions of retinopathy from such photographs of diabetic retinas. The system could allow internists to see the entire population of diabetics efficiently. "This is the only method I foresee improving the poor compliance situation," Dr. Sinclair said. The downside is that, "You're taking the optometrist and the ophthalmologist out of the screening loop," he said. "Now we're going to filter to their offices the people who need careful monitoring and treatment."

The outcome of this will be the loss of routine dilated examinations for the optometrist, but a gain in examinations of diabetics with retinopathy.

For Your Information:

Kari Blaho, PhD, is director of research for the Department of Emergency Medicine and Clinical Toxicology, UT Medical Group, 842 Jefferson Ave., Ste. A-645, Memphis, TN 38103; (901) 545-8699. She has no direct financial interest in any products mentioned in this article, nor is she a paid consultant for any companies mentioned.

Peggy Schiavo, MS, RD, CDE (certified diabetic educator) is clinical dietitian at Pennsylvania Hospital. She can be contacted c/o Food and Nutrition, 800 Spruce St., Philadelphia, PA 19107; (215) 829-3286, ext. 6034. Ms. Schiavo has no direct financial interest in any products mentioned in this article, nor is she a paid consultant for any companies mentioned.

Stephen H. Sinclair, MD, may be reached at Crozer Chester Medical Center, Ste. 233, 1 Medical Center Blvd., Upland, PA 19013; (610) 872-5430. Dr. Sinclair has a direct financial interest in the Philadelphia Ophthalmic Imaging Systems Diabetic Auto mated Retinopathy Screener.

Susan E. Marren, OD, may be reached at 503 Fourth St., River ton, NJ 08077; (609) 829-4229. Dr. Marren has no direct financial interest in the products mentioned in this article, nor is she a paid consultant for any companies mentioned.

Call the ADA hotline at (800) DIABETES. For more information regarding the ophthalmic imaging service introduced by Dr. Sinclair and associates, see www.POIS.com. or www.diabetes.org.

Therapy for Diabetes Mellitus and Related Disorders and Nutrition Guide for Professionals are available from the American Diabetes Association, (800) 232-3472.