Improving Sight in People With Diabetes & Diabetic Retinopathy

Clinical trial tests effects of supplements for vision

By A. Paul Chous, MA, OD, FAAO 
Tacoma, WA

I have written previously that the main reason people with diabetes have trouble seeing on an eye chart is the same reason other people without diabetes have trouble – because we need a recent eyeglass or contact lens prescription to correct for nearsightedness, farsightedness, astigmatism, and presbyopia (see my previous dLife column, "Nearsightedness, Farsightedness and Astigmatism – What's the Difference," February 2008). Beyond this, a good deal of research shows that people with diabetes have problems with seeing in the ‘real world,' where what we need to see is not typically black letters on a white background, but objects with low contrast (a grey car on a cloudy day) and in low light (driving at night). Moreover, people with diabetes are more likely to have problems with color vision and efficient processing of visual stimuli received by the eye and interpreted by the brain (see my previous dLife column, "Macular Pigment and Diabetes," October 2012). The question is – can anything other than eyeglasses, contact lenses, or LASIK treatment help with these kinds of visual function issues? Consider supplements for vision.

We now have evidence that a novel, multi-component nutritional supplement may protect and improve visual function in people with both diabetes and diabetic retinopathy, and that the same formula preserves normal retinal structure and metabolism in an animal model of diabetic retinopathy. The formula consists of a number of molecules previously shown to positively impact eye health of animals with diabetes, and some studies of humans with diabetes: lutein, zeaxanthin, benfotiamine, Pycnogenol , alpha-lipoic acid, resveratrol, curcuminoids, vitamin D, n-acetyl cysteine, omega-3 fatty acids, and several others (for more information, see my previous dLife column, "Doctor – Can't I Just Take a Pill? (Part 2), December 2007). All of these components are currently available over-the-counter as nutritional supplements; the novelty of this formula is that they have been put together in a single capsule for ease of use and synergism.

In rats with diabetes, this formula was shown to minimize damage to the energy-producing mitochondria within retinal cells, to normalize electrical activity within the retina (assessed by electro-retinogram), to lower levels of pivotal proteins that lead to severe diabetic retinopathy (nuclear-factor Kappa Beta – nfKB. and Vascular Endothelial Growth Factor – VEGF), and to prevent early damage to capillaries delivering blood to the retina1(a crucial event in the development of diabetic retinopathy.)

To assess the effects of this formula in human beings, I am running a clinical trial in my Tacoma, WA practice called the Diabetes Visual Function Supplement Study (DiVFuSS)2, a six-month, placebo-controlled study investigating contrast sensitivity, color vision, visual field sensitivity (detecting dim flashes of light on a light background), retinal integrity (using optical coherence tomography – OCT – a sort of optical ultrasound) and a survey of symptoms associated with diabetic neuropathy, as well as blood tests to detect proteins associated with diabetic retinopathy, in people with pre-existing diabetes and either no or mild diabetic retinopathy.

Although the study is not yet completed, peer-reviewed, or published, data from the first 46 people to complete the trial show statistically significant improvements in contrast sensitivity, visual field sensitivity and color vision, reduced symptoms in patients with diabetic neuropathy, and reductions of C-reactive protein (CRP), a chemical implicated in diabetic macular edema. Subjects on placebo showed no such improvements. No side effects have been reported thus far, and a number of study participants have commented that their vision ‘in the real world' is dramatically better. Two patients on the test formula have also shown a marked lessening of their diabetic retinopathy (see images below). Additional studies of the formula, including its use in patients with more severe retinopathy, and as an add-on therapy in patients with sight-threatening retinopathy requiring laser or injection therapy, are being planned. The formula is now available as EyePromise DVS through eye doctors' offices or on-line. Stay tuned.

Image of patient's left retina at beginning of our study. Note the white spots (hard exudates) signifying leakage of protein/fat from the retinal blood vessels.	Image of the same eye at study completion. Note resolution of hard exudate.