Bad blue light, macular pigment, and prescriptive carotenoids

Our sun, modern indoor blue LED lighting, cell phones, and computer displays all emit “bad blue” radiation defined as a wavelength band of 435 nm ± 20 nm. Such radiant energy degrades visual quality, can enhance or disrupt our inborn mammalian circadian rhythm, and photochemically damage our retinas.^1-3

While our corneas block UVB and our ocular lens obstructs UVA, such longer wavelength “bad blue” radiation easily penetrates past the cornea and lens. Bad blue radiation is particularly hazardous to children, young adults, “clear - ocular - lens” baby boomers, and the pseudophakic patient, to whom blue radiation is transmitted directly to the retina. Even infant retinas are increasingly exposed to ‘bad blue’ tablet screen images.

More from Dr. Richer: Lutein and zeaxanthin: Beyond retinal health

ODs need to think about light management

Ophthalmic lens manufacturers have embraced blue light protection with new spectacle products, such as Essilor’s Crizal Prevencia, Hoya’s Recharge, Eye Solutions Technologies’ BluTech Lenses, and VSP TechShield. Yet dietary ocular carotenoids (lutein and zeaxanthin) also protect against bad blue and retinal degeneration.

However, two studies have shown that a significant percent of the population who could also benefit from carotenoid supplementation aren’t being helped.^5,6

Optometrists are sitting on a powerful public health and practice enhancement tool to manage the blue light hazard risk of patients well beyond the effect of ophthalmic filters. The dietary ocular carotenoids lutein and zeaxanthin improve visual performance and night vision while protecting the desirable circadian rhythm mediated “good blue.”

More from Dr. Richer: Mesozeaxanthin and who needs to consume it

What is this circadian rhythm? This system regulates our day/light cycle via suppression of melatonin in the morning and secretion of melatonin at nightfall. The hypothalamic-pituitary axis in turn regulates our sleep, autonomic nervous system, mood, motor/cognitive performance, and even our hormones and cellular health.³

The circadian rhythm is modulated by our 480 nm responsive, so-called 4^th extra foveal iPGC photoreceptor that transmits good blue to our pineal gland via the suprachiasmic nucleus, a bundle of neural tissue lying between the optic chiasm and hypothalamus. Most, but not all, spectacle tints block this beneficial 480 nm bandwidth.

Dietary and supplemental lutein and zeaxanthin, by virtue of both their spectral and central retinal topographical distribution, never interfere with our circadian rhythm. It’s time for the optometrist to think about “light management” beyond spectacle tints.

Next: Protective effects of carotenoids

Protective effects of carotenoids

The protective effects of carotenoids against bad blue radiation have been proven in several recent experimental cellular molecular biology published papers.^{1, 2} Carotenoids have additional emerging benefits beyond bad blue protection and protecting our patients’ circadian rhythms.

There is emerging evidence for protection against both early age-related macular degeneration (AMD) and cataract in the young consumer and baby boomer.⁷

While superior visual function has been scientifically established over the past few decades, dietary lutein and zeaxanthin are now known to make their way to our brains. The potential added cognitive functional benefit from dietary and supplemental carotenoids, is now emerging within the scientific literature.⁸

In our research and clinical experience, self-described driving ability can also be ameliorated in a few months in 80 percent of aging patients by prescribing appropriate lutein and zeaxanthin supplementation.⁹ That means happier, safer drivers who will seek out those optometrists who provide expanded “night vision” diagnostic and treatment services.

More from Dr. Richer: ODs must teach patients about proper nutrition

Optometrists with confidence can emphasize that the two dietary carotenoids lutein and zeaxanthin, compared with spectral tints, optimally protect us against the modern blue light hazard while at the same time promoting visual performance, superior night driving vision and preserving our circadian rhythm.

It’s time to identify underprotected patients by measuring their macular pigment. The gold standard research technique is heterochromic flicker photometry (HFP). One streamlined and validated clinical instrument for determining macular pigment optical density, based on HFP is the QuantifEye.^10-12 Stop worrying about on line refractions and Internet eyeglasses. Enlighten your patients.

References:

1. Sasaki M, Yuki K, Kurihara T, Miyake S, Noda K, Kobayashi S, Ishida S, Tsubota K, Ozawa Y. Biological role of lutein in the light-induced retinal degeneration. J Nutr Biochem. 2012 May;23(5):423-9.

2. Kuse Y, Ogawa K, Tsruma K, Shimazawa M, Hara H. Damage of photoreceptor-derived cells in culture induced by light emitting diode-derived blue light. Sci Rep. 2014 Jun 9;4:5223.

3. Bonmati-Carrion MA, Arguelles-Prieto R, Martinez-Madrid MJ, Reiter R, Hardeland R, Rol MA, Madrid JA. Protecting the melatonin rhythm through circadian healthy light exposure. Int J Mol Sci. 2014 Dec 17;15(12):23448-500.

5. Davis RL. Preliminary results in macular pigment optical density associated with and without zeaxanthin and lutein supplementation. Adv Ophthalmol Vis Syst. 2015;2(6). 00066. DOI: 10.15406/aovs.2015.02.00066.

6. Moeller SM, Voland R, Sarto GE, Gobel VL, Streicher SL, Mares JA. Women's Health Initiative diet intervention did not increase macular pigment optical density in an ancillary study of a subsample of the Women's Health Initiative. J Nutr. 2009 Sep;139(9):1692-9.

7. Ma L, Hao ZX, Liu RR, Yu RB, Shi Q, Pan JP. A dose-response meta-analysis of dietary lutein and zeaxanthin intake in relation to risk of age-related cataract. Graefes Arch Clin Exp Ophthalmol. 2014 Jan;252(1):63-70.

8. Johnson EJ. A possible role for  lutein and zeaxanthin in cognitive function in the elderly. Am J Clin Nutr. 2012 Nov; 96(5):1161S-5S

9. Richer S, Park D-W, Epstein R, Wrobel JS, Thomas C. Macular Re-pigmentation Enhances Driving Vision in Elderly Adult Males with Macular Degeneration. J Clin Exp Ophthalmol. 3:217. Available at: http://www.omicsonline.org/elderly-adult-males-with-macular-degeneration-2155-9570.1000217.php?aid=6045. Accessed 09/2/15

10. van der Veen RL, Berendschot TT, Hendrikse F, Carden D, Makridaki M, Murray IJ. A new desktop instrument for measuring macular pigment optical density based on a novel technique for setting flicker thresholds. Ophthalmic Physiol Opt. 2009 Mar;29(2):127-37.

11. Mutolo MG, Forma G, Carbon G, Jennings BJ , Iannaccone A. Macular Pigment Optical Density (MPOD) Testing in Middle-Aged Adults: Comparison between a Standard Heterochromatic Flicker Photometry (Std-HFP) Method and the QuantifEYE® (QE), a Desktop Device Designed for Clinical Applications. Poster presented at: Association for Research in Vision and Ophthalmology (ARVO), May 1-6, 2010, Ft. Lauderdale, FL.

12. de Kinkelder R, van der Veen RL, Verbaak FD, Faber DJ, van Leeuwen TG, Berendschot TT. Macular pigment optical density measurements: evaluation of a device using heterochromatic flicker photometry. Eye (Lond). 2011 Jan;25(1):105-12.