By A. Paul Chous, MA, OD, FAAO, CDE
Hi there – this is Paul Chous and I’m an optometrist with a private practice specializing in diabetes eye care and education in Tacoma, WA. Today I’d like to talk about a newly published randomized clinical trial for which I was Principal Investigator: The Diabetes Visual Function Supplement Study, or DiVFuSS (British Journal of Ophthalmology 2016). There is a lot of scientific evidence showing that multi-component nutritional supplements containing anti-oxidants, including zeaxanthin and lutein, improve visual function in patients with age-related macular degeneration (AMD), and even lower the risk of disease progression in certain patients (AREDS and AREDS2). We were interested in seeing if we could achieve these benefits in patients with diabetes and diabetic retinopathy which, after all, remains the leading cause of new blindness in working age Americans.
We conducted a placebo controlled trial using a combination of ingredients linked to the blockade of biochemical pathways underlying diabetic eye disease. Adult patients with type 1 and type 2 diabetes participated, and we measured macular pigment optical density (MPOD), contrast sensitivity, color vision, visual field, diabetic peripheral neuropathy symptoms, blood lipids and blood markers of inflammation like C-reactive protein (hsCRP) at baseline and 6 months – importantly, there were no differences between the placebo and test subjects at the start of our trial. No adverse events occurred, and patients on the test formula had significant improvements on nearly all measures (MPOD, contrast sensitivity, color vision and visual field improved by 31%, 19%, 21% and 12%, respectively). Additionally, the study found a 31% reduction in diabetic neuropathy symptoms and a 50% reduction in hsCRP with no significant change in average blood glucose (HbA1c) between the groups.
Previous studies have shown that MPOD is lower in patients with diabetes and diabetic retinopathy, that diabetes affects visual function before retinopathy becomes clinically observable, that damage to retinal vasculature is occurring even when we don’t see it, and that retinopathy develops in some patients despite excellent diabetes control. We also know that half of patients never achieve target A1c levels. What our findings show is that the test formula significantly raised MPOD, improved visual function and reduced inflammatory proteins linked to diabetic retinopathy independently of blood sugar control. This means we now have an alternative and complementary strategy for helping our patients with diabetes before they develop severe eye disease and irrespective of their level of blood sugar control. In addition, an animal study conducted with the DiVFuSS formula showed dramatic reductions in VEGF and retinal damage without significantly affecting blood sugar levels.
My takeaway messages are: We should discuss and measure MPOD in our patients with and at-risk for diabetes; We now have solid scientific evidence that a multi-component nutritional supplement, the DiVFuSS formula (EyePromise® DVS), benefits patients with diabetes in multiple ways, including significant improvements in visual function; Diabetes damages the eyes even when we don’t see it and despite tight metabolic control, so it makes biologic sense to target pathways linked to the development of diabetic retinopathy before overt damage occurs; We can, in fact, do more to help our patients with diabetes above and beyond educating them about the importance of good diabetes control (counseling), examining them for sight-threatening retinopathy (watching) and referring them for treatment if and when severe retinopathy develops (waiting). This gives us an opportunity to not only help our patients, but to differentiate our practices from those who merely counsel, watch and wait to treat. Tell a friend.
Dr. Paul Chous was diagnosed with type 1 diabetes mellitus at age five. He completed his undergraduate education at Brown University and UC Irvine, and then received his Masters and Doctorate of Optometry degrees with highest honors from UC Berkeley. Dr. Chous has a private practice specializing in diabetes eye care and education in Tacoma, WA.
Dr. Chous won the American Diabetes Association’s Distinguished Public Service Award in 1998. He is the author of Diabetic Eye Disease: Lessons From a Diabetic Eye Doctor (Fairwood Press, Seattle, 2003), which was included in the “Top 12 Diabetes Books” by Diabetes Update magazine in 2004. He is a feature writer for the web sites dLife – Your Diabetes Life and Diabetes In Control, an ophthalmic consultant to Children With Diabetes and the Diabetes Exercise and Sports Association, Section Editor of the Kestrel Diabetes Sourcebook, and an adjunct instructor at NOVA Southeastern University College of Optometry in Fort Lauderdale, FL. Dr. Chous also serves as optometric representative to the National Diabetes Education Program (NDEP), a division of the US National Institutes of Health (NIH).