VISION EXPO EAST
I had the pleasure of attending a number of lectures at this year’s Vision Expo East meeting. Here are highlights of two.
OCT, OCT-A, The What, When, How
Julie Rodman, OD, FAAO, and Diana L. Shechtman, OD, FAAO, presented an update on all things OCT. Their talk focused on the clinical utility of OCT angiography (OCT-A) in the optometric practice. OCT-A is a noninvasive modality that allows visualization and 3D reconstruction of retinal and choroidal blood flow. OCT-A identifies blood vessels by detecting blood flow–induced changes in the OCT reflectance signal. No contrast dye is required, and images can be obtained in seconds. OCT-A is ideal for visualization of retinal ischemia and neovascularization.
Drs. Rodman and Shechtman said that OCT-A has the potential to change how eye care providers manage common pathologies such as age-related macular degeneration (AMD) and diabetic retinopathy (DR). Clinicians can detect choroidal neovascularization in AMD with OCT-A earlier than with traditional OCT or fluorescein angiography. Although the decision to treat AMD with anti-VEGF agents is still based on the presence of exudation on spectral-domain OCT or leakage on fluorescein angiography, research is under way to determine whether some choroidal neovascularization should be treated earlier based on OCT-A findings.
In patients with DR, macular involvement can present as either macular edema or ischemia. Ischemic changes predict DR progression, and identification of poor perfusion with OCT-A could be clinically meaningful. Drs. Rodman and Shechtman noted that visual prognosis in those undergoing anti-VEGF therapy for diabetic eye disease is worse if macular ischemia is present.
OCT has evolved rapidly over the past 15-plus years, starting with time-domain OCT, then spectral-domain OCT, and now OCT-A. Forward-thinking eye care providers are embracing this technology to help identify disease progression earlier.
Changing the Paradigm in DR Management
James Thimons, OD, reviewed the state of the diabetes epidemic and discussed strategies to prevent or delay retinal microvascular complications secondary to diabetes.
Dr. Thimons said that, with an estimated 30 million diabetic patients in the United States and nearly 90 million individuals with prediabetes (defined as having a hemoglobin A1c of 5.7-6.5%), the role of the eye care provider in managing diabetic eye disease will certainly expand. DR continues to be the leading cause of blindness in working-aged adults and care for people with diagnosed diabetes accounts for 25% of all US health care expenditures, according to the journal Diabetes Care.1 Anti-VEGF injection therapy has revolutionized the management of diabetic eye disease, and it is now used for treatment of diabetic macular edema and both nonproliferative and proliferative DR.
But is waiting until a patient with diabetes requires anti-VEGF therapy the most appropriate therapeutic approach? Although disease duration and blood glucose control remain the most important risk factors for DR progression, Dr. Thimons presented strong evidence that omega-3 fatty acid supplementation, primarily with docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), may have a significant impact.
One of the highest concentrations of omega-3s found in the body (specifically, DHA) is in the retina. Dr. Thimons said that increased serum concentrations of omega-3s are associated with decreased rates of diabetes and improved glycemic control. Dr. Thimons shared recent evidence suggesting that patients with higher serum levels of omega-3s have significantly lower risk of developing sight-threatening DR. Additionally, in patients receiving ranibizumab (»Lucentis, Genentech) as treatment for diabetic macular edema, the addition of DHA/EPA supplements reduced OCT central subfield thickness more than the injections alone.
The market for nutritional intervention in diabetes could grow rapidly if evidence-based medicine further supports the use of omega-3 supplements. If sufficient clinical evidence emerges, nutraceuticals such as nūretin (PRN Therapeutics), which provides 1200 mg EPA and DHA in a 1:5 concentration, may play a role in treating patients with DR.
RETINA IN THE REAL WORLD
It’s one thing to understand the conceptual nature of monitoring retinal disease. It’s another to actually be on the lookout for these diseases. ODs who have a firm understanding of retinal pathologies can give their patients and their practices a head start in the fight against these blinding diseases. Early intervention is key, but that intervention cannot occur without proper identification.
- American Diabetes Association. Economic costs of diabetes in the U.S. in 2017. Diabetes Care. 2018;41(5):917-928.