Advances in Diabetic Retinopathy

Innovations in treatment over the past 15 years for people with diabetes who are most at risk of blindness

With Thomas W. Gardner, MD and Scott D. Isaacs, MD

Recent advances in the treatment of diabetic retinopathy give clinicians several new options, beyond surgery, to preserve vision in patients with this condition. In response to the evidence-based developments in care, the American Diabetes Association issued a new position statement on diabetic retinopathy,1 as an update to its previous guidance,2 issued in 2002. 

Scientists at the National Eye Institute (NEI) have been seeking ways to detect diabetic retinopathy at earlier stages. For example, adaptive optics, which enables clinicians to detect subtle changes in blood vessels and tissue in the retina and through improved imaging, such as optical coherence tomography, that uses light waves to detect retinal changes.   

ADA promotes advances in treatment to prevent vision loss in people with diabetes.Ophthalmologists now employ wide-field fundus photography to look for occult microvascular damage in the eye. And, treatment has evolved to include not only lasers but injections of medications—such as bevacizumab, ranibizumab, and aflibercept into the vitreous to suppress vascular endothelial growth factor (VEGF)—and corticosteroids, particularly when people fail to respond to anti-VEGF therapy.

“Endocrinologists certainly have much better tools to use that than they did 15 years ago,” said Thomas W. Gardner, MD, MS, professor of ophthalmology and visual sciences at the Kellogg Eye Center at the University of Michigan, in Ann Arbor, and senior author of the position statement, which appears in Diabetes Care

Another factor, according to the authors, is that endocrinologists have markedly better treatments and technologies for managing high blood glucose—an important risk factor for retinal damage. 

Although the options for vision preservation have expanded for many patients, Dr. Gardner told EndocrineWeb that many people with diabetes lack sufficient health insurance, or access to specialty care, and thus cannot take advantage of these better therapies.

“There are good data from a number of studies that the risk of developing severe vision-threatening retinopathy is down from 15-20 years ago,” he said. “But that is in patients who have access to the treatments and who have insurance. Patients who don’t have the financial wherewithal and access to state-of-the-art endocrine care don’t do as well.”

However, an estimated 35.3% of people with diabetes will develop retinopathy associated with concomitant diabetes, and roughly 7.5% of people who have diabetes develop proliferative retinopathy, a more aggressive form of the eye disease.3

Dr. Gardner described the vision gains from anti-VEGF agents as “modestly better” in general, but markedly so for certain people. “Patients with diabetic macular edema are much more likely to gain three or more lines of vision with the injection therapies than when we treated them with lasers,” he said. “Not everyone gains three lines, but not everybody [has progressed] enough to gain by three lines.”

Causes of diabetic retinopathy

Given the rise in the incidence of diabetes, diabetic retinopathy is now the most frequent cause of new cases of blindness among people between the ages of 20 and 70, according to authors.

Several factors related to diabetes are known to contribute to the risk of retinopathy:4,5

  • Duration of diabetes  
  • Poor blood glucose control
  • Hypertension
  • Hyperlipidemia
  • Anemia
  • Not seeking annual ophthalmic screenings
  • Development of cataracts

Intensive insulin therapy in patients with both type 1 and type 2 diabetes can reduce the risk of developing diabetic retinopathy by roughly 25% as compared with standard care, and appears to reduce the odds of progressive retinopathy by 34% to 76%.2

While nutrition plays a well-known role in the course of diabetes, it also a clinically relevant factor in preventing the development of diabetic retinopathy.6 At the outset, patients' nutritional status should be assessed using the Subjective Global Assessment, and they can be counseled regarding dietary strategies needed to address deficiencies or excesses in an effort to preserve vision.

Scott D. Isaacs, MD, medical director of Atlanta Endocrine Associates, told  EndocrineWeb, the key point for endocrinologists is to make sure that their patients with diabetes see an ophthalmologist at least annually, and more often when requested by the eye specialist.

“The article highlights that a basic eye exam that would be performed by an endocrinologist is not sufficient anymore, as the modern retinopathy screening tools utilized by ophthalmologists are far superior to any in-office retinal examination performed by an endocrinologist,” Dr. Isaacs said.

“An endocrinologist who does his own eye screenings without using an ophthalmologist would be delivering care that is below the current standard of care and could miss eye pathology that is easily detected by today’s advanced methods,” Dr. Isaacs added. “It is like looking at a road map through a pinhole. Why would you want to do that when there are techniques to allow an ophthalmologist to see the entire road map?”

Since its inception in 2002, the Diabetic Retinopathy Clinical Research Network, established by the NEI, has initiated large-scale trials to evaluate new therapies and compare different treatments aimed to improve diabetic eye diseases. The network comprises more than 350 physicians from 140 clinical sites, most of which are private practice eye clinics, which fosters innovative treatments to advance more quickly from research into community practice.

Continue Reading:
Cardiovascular Effects of Diabetic Retinopathy in Patients with Type 2 Diabetes
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