Patients with type 1 and type 2 diabetes should undergo regular, comprehensive screenings for diabetic retinopathy while also optimizing glycemic control and blood pressure to reduce the risk for or slow progression of the condition, according to an updated position statement released by the American Diabetes Association.
The statement also notes that recent screening advances, including the widespread adoption of OCT and wide-field fundus photography, have aided in the detection of “clinically silent” microvascular lesions, whereas new therapies, including intravitreous anti-VEGF injections, are available to treat diabetic macular edema as well as proliferative diabetic retinopathy.
“Diabetic retinopathy is actually the most common cause of new cases of blindness in adults who live in developed countries and are between the ages of 20 and 74 [years],” Thomas W. Gardner, MD, MS, professor of ophthalmology and visual sciences at the Kellogg Eye Center at the University of Michigan, said in a press release. “Over the past decade, new research and significant improvements in technology have aided our ability to diagnosis and treat diabetic retinopathy, and advances in medications are giving people with diabetes the opportunity to improve glucose management and potentially avoid or delay the progression of complications such as retinopathy.”
In the statement, Gardner, Sharon D. Solomon, MD, of the Wilmer Eye Institute at Johns Hopkins Medicine, and colleagues wrote that, after duration of diabetes, hyperglycemia is the most consistently associated risk factor for retinopathy, citing clinical trials including the UK Prospective Diabetes Study (UKPDS), the Diabetes Control and Complications Trial (DCCT) and the ACCORD trial, all of which suggested that intensive glucose control reduced risk for and severity of diabetic retinopathy.
“This can be translated clinically to a higher likelihood of preserving sight and to a reduced need for treatment,” the researchers wrote. “Furthermore, all three studies demonstrated that years after the initial clinical trial ended, the treatment effect of intensive glycemic control persisted, despite the fact that both treatment groups had similar levels of HbA1c. In fact, 25 years after the cessation of the DCCT, ocular surgery rates were reduced in those who had been assigned to intensive glycemic control.”
The statement noted that adults with type 1 diabetes should be screened within 5 years after diagnosis; patients with type 2 diabetes should undergo eye screenings at the time of diagnosis. Women with pre-existing type 1 or type 2 diabetes who are planning pregnancy or have become pregnant should be counseled on the risk for development or progression of diabetic retinopathy, and eye examinations should occur before pregnancy or in the first trimester.
Anti-VEGF therapy is currently the standard of care for central-involved diabetic macular edema. Multiple emerging therapies, including intravitreous steroid therapy, dexamethasone and fluocinolone, are rarely used as first-line treatments given the increased adverse events of cataract and glaucoma associated with steroid use, the researchers wrote. Panretinal laser photocoagulation is commonly used to manage proliferative diabetic retinopathy, but anti-VEGF therapy is a “potentially viable alternative treatment,” the researchers noted, citing the rapid regression of retinal neovascularization observed in treated central-involved diabetic macular edema.
The researchers noted that a consensus has not been reached, but telemedicine can be an effective option to screen for diabetic retinopathy in patients when the ratio of providers to patients is low, the distance to reach a provider is prohibitive or the alternative is no patient screening. Eye injections, such as anti-VEGF therapy, have been shown in studies to be more cost effective vs. laser monotherapy for diabetic macular edema, but future studies are needed to determine the cost effectiveness of anti-VEGF medications as a first-line treatment for proliferative diabetic retinopathy.
“The [ADA’s] diabetic retinopathy position statement is based upon the recommendations of a team of ophthalmological experts who compiled information from more than 45 research studies, and these updated guidelines are a significant component of our efforts to offer evidence-based information to providers and people with diabetes,” William T. Cefalu, MD, chief scientific and medical officer of the ADA, said in the release.
The position statement was published online in Diabetes Care. – by Regina Schaffer
Disclosure: Cefalu is chief scientific and medical officer for the ADA. Gardner reports consulting for BetaStem, Janssen, Johnson & Johnson, KalVista, Novo Nordisk and PureHealth. Please see the position statement for the other authors’ relevant financial disclosures.