Speaker: Help your patients prevent diabetic retinopathy

ATLANTA — Here at SECO 2011, presenter W. Lee Ball, OD, FAAO, urged attendees at a course sponsored by PRIMARY CARE OPTOMETRY NEWS to "plant key messages" among your patient with diabetes.

"Diabetes is the leading cause of preventable new-onset blindness in working age adults," Dr. Ball told more than 200 attendees. "Forty percent of Americans who would benefit from sight-preserving treatment do not receive the necessary care."

Dr. Ball said there are 55 new cases of preventable blindness diagnosed per day due to diabetes. "Ninety percent of vision loss from diabetic retinopathy is preventable if treated early," he said.

Co-presenter Jessica McCluskey, MD, said, "Diabetic retinopathy does not get enough press. Patients don't know diabetes affects their eyes. Many patients are not aware of the long-term effects diabetes can have on vision."

Dr. Ball agreed, saying "Diabetes doesn't get as much press as cardiovascular disease. In adults with diabetes, 68% die of heart disease or stroke, the risk for stroke is two to four times higher, 75% have high blood pressure and smoking is like adding fuel to the fire."

Dr. Ball said he asks his patients two questions regarding smoking: Do you smoke? Do you want to quit? He urges optometrists to help their patients quit smoking by recommending they call (800) QUIT-NOW or go to www.smokefree.gov, which provides information on a no-cost government program for smoking cessation.

"Landmark studies show that by maintaining tight glycemic control in addition to blood sugar control and lipids, you can greatly reduce complications from diabetes," Dr. Ball said.

The Diabetes Prevention Program lifestyle intervention is a comprehensive program to reduce fat and caloric intake, increase physical activity to 50 minutes 5 days a week and a loss of 5% to 7% of body weight. Dr. Ball said the program was shown to reduce the risk of developing diabetes by 58%, and it is almost twice as effective as taking an oral diabetes medication such as metformin."

"The effect was even higher among older patients," he said. Among those 60 and older, the risk was reduced by 71%.

Dr. Ball is immediate past chair of the Pharmacy, Podiatry, Optometry and Dental work group for the National Diabetes Education Program. "We talk about the complications of diabetes and ways to reduce the morbidity and premature death associated with the disease," he said. "Periodontal disease correlates with poor glycemic control. These individuals have chronic low-grade inflammation in their bodies, which makes it tough for them to control their blood glucose levels.

"Form a team of diabetes care providers in your community and work together to provide total care for your patients with diabetes," Dr. Ball continued. "The effects of diabetes occur everywhere in the body that blood travels, so all providers have a vested interest in improving care for these patients."

Among the potential complications of diabetes, retinopathy outranks cardiovascular disease, neuropathy and nephropathy, Dr. McCluskey said.

Nonproliferative diabetic retinopathy is categorized as mild, moderate, severe and very severe, Dr. McCluskey said. Proliferative diabetic retinopathy is categorized as early, high-risk and advanced. Proliferative diabetic retinopathy can present initially with very good vision, which can be deceiving to the patient. Diabetic macular edema can be present at any level of diabetic retinopathy, she said.

"Nonproliferative diabetic retinopathy can result in microaneurysms, intraretinal hemorrhages, retinal edema, intraretinal exudates, dilation and beading of the retinal veins, cotton-wool spots (infarct of the retinal nerve fiber layer) and capillary nonperfusion," Dr. McCluskey said.

"If your patient has poor metabolic control, elevated blood pressure, congestive heart failure, renal failure, anemia and high cholesterol, they will have problems with macular edema," she continued. "It all goes hand in hand.

Dr. McCluskey cautioned attendees to be aware of the nonocular medications their patients are taking. "Avandia (rosiglitazone maleate, GlaxoSmithKline) can have many systemic side effects," she said. "It is associated with diabetic macular edema. If you have a patient with chronic macular edema and you're doing everything and it's not getting better, review their medication list again. Contact their primary care physician if you have any questions regarding systemic medications the patient is taking."

Dr. McCluskey addressed available treatments for diabetic retinopathy.

"Laser is still the gold standard for treatment," she said. "The ETDRS shows that laser reduces the risk of moderate vision loss by 50%. We absolutely laser."

Dr. McCluskey said in her practice they perform Avastin (bevacizumab, Genentech) injections, bring patients back in 4 to 6 weeks, then perform focal laser photocoagulation. She said some patients respond to injection within 24 hours with a decrease in retinal thickness and an increase in vision.

"The laser works better if you get rid of the fluid first," she said.

She referenced a study that showed that the reduction in central macular thickness was most significant in patients who received both Avastin and laser.

"Another medication we can inject is an intravitreal steroid, triamcinolone," Dr. McCluskey said. "Avastin is my first choice in most patients. However, triamcinolone can be very effective, as it does have some antivascular endothelial growth factor (anti-VEGF) activity and can help dry out the macula."

She said intravitreal steroid is not normally the first choice because it has more complications and risks than Avastin, such as increase in IOP, glaucoma, cataracts and risk of infection.

"The one I'm concerned about is glaucoma," Dr. McCluskey said. "If you end up causing a severe steroid response, and the patient needs a trabeculectomy, you have created a second problem in addition to the macular edema."

An attendee asked Dr. McCluskey if you would see the same post-injection response with Lucentis (ranibizumab, Genentech).

"Yes, Avastin and Lucentis are very similar," Dr. McCluskey said. "When we read the studies, anything that's proven for Lucentis we extrapolate for Avastin, and vice versa."

Dr. McCluskey provided guidelines on exam schedules for patients with diabetes.

"Patients with type 1 diabetes need to be seen within 5 years of diagnosis," she said. "With type 2, they need to be seen as soon as they are diagnosed. You will frequently find a patient who needs laser treatment on their first exam. This is probably because they've had diabetes before developing symptoms.

"Pregnant patients with diabetes should be seen before getting pregnant or early in the first trimester," Dr. McCluskey continued. "Those with gestational diabetes should be seen every trimester."

Dr. McCluskey is a retina specialist with the Thomas Eye Group in Atlanta. Dr. Ball is on staff at the Joslin Diabetes Center at the Beth Israel Deaconess Medical Center in Boston.

PRIMARY CARE OPTOMETRY NEWS will be sponsoring another 2-credit continuing education course during Optometry's Meeting in Salt Lake City. PCON Editor Michael D. DePaolis, OD, FAAO, will moderate "PCON Live," featuring a panel of PCON Editorial Board Members and contributors June 18. Watch www.PCONSuperSite.com for more details.