Unived Eye Health

Lutein and Zeaxanthin: They are carotenoids that are widely distributed in fruits and vegetables and appear to have antioxidant properties. A higher dietary intake of carotenoids has been associated with beneficial effects in several systemic diseases specifically eye disorders, with the protection of the retina from phototoxic light damage. (1)

• Lutein has been demonstrated to exert an extremely potent antioxidant action by quenching singlet oxygen and scavenging free radicals. It is also involved in reducing phototoxic damage to photoreceptor cells by its ability to filter blue light. (1)
• Lutein and zeaxanthin along with their metabolites are present in the human macula. Collectively, lutein, zeaxanthin, and meso-zeaxanthin (an isomer of zeaxanthin) form the macular pigment. As antioxidants and with their ability to filter blue light they are reported to protect the retina and thus vision. (2)
• In a double-blind, placebo-controlled, parallel, three-arm study a total of 93 subjects were randomized and were followed up for 180 days. Lutein and Zeaxanthin supplementation, with natural carotenoids and without natural mixed carotenoids showed statistically significant improvements in the macular pigment optical density (MPOD) levels when compared to baseline. A higher level of MPOD reduces the risk of age-related macular degeneration (AMD) and provides the necessary protection against oxidative damage and blue light. (3)

Bilberry Extract: Bilberry is a plant native to European and the Northern United States. It has been used as food for its extensive nutritive values as well as for its medicinal properties since the Middle Ages. The pharmacologically most active component of the bilberry extract are anthocyanosides which carry its potential therapeutic benefits in various systemic disorders.

• It works towards preventing ophthalmologic disorders like cataracts and macular degeneration by enhancing the delivery of oxygen and blood circulation to the eye and scavenging free radicals responsible for disrupting the collagen fibers in the eye which lead to these particular disorders. (4)
• The active components of Bilberry also show an affinity towards the pigmented area of the eye which is responsible for vision and adjustment of light and dark. (4)
• Improved night-time visual acuity, faster adjustment to darkness, and faster restoration of visual acuity after exposure to glare were observed in individuals with impaired visual acuity such as retinitis pigmentosa and hemeralopia (inability to see in direct bright light) on supplementation.
• Studies have shown Bilberry extract may have a role in preventing the risk of developing cataracts.
• Consumption of bilberry extracts may offer significant protection against the development of glaucoma due to its collagen-enhancing and antioxidant properties.
• In a study, eight patients with glaucoma were given a single oral dose of 200mg Bilberry extract and improvement was demonstrated based on electroretinography. (4)

Beta Carotene: Vitamin A is an essential fat-soluble vitamin, meaning it cannot be synthesized by the body and has to be consumed through the diet.

• Beta-carotene plays a major role in the pathways which are responsible for generating vision. It is metabolized into retinol, which is an essential biochemical of the eye. (6)
• Supplementation with beta-carotene along with other essential vitamins and minerals reduces the risk of developing advanced AMD. (7)
• ·Xeropthalmia is a spectrum of ocular diseases caused due to the deficiency of Vitamin A. It is characterized by dryness in the conjunctiva and cornea of the eye, ulcers or inflammation around the eye as well as night-blindness which is the inability to see clearly in dim light. (6)
• Vitamin A is a component of the protein rhodopsin, which allows seeing in low-light conditions. Hence, a deficiency in vitamin A can lead to night blindness.
•  It also supports the function of the cornea, which is the protective layer of the eye. Individuals deficient in vitamin A may find their eyes produce too little moisture to stay lubricated. (6)

Zinc

• The highest concentration of zinc is present in the retina and choroid, suggesting its essential role in maintaining eye health.
• Along with vitamin A it is involved in the generation of vision. Night-blindness can occur in the case of zinc deficiency even in the presence of adequate vitamin A.
• When an elderly population with early stages of macular degeneration was supplemented with zinc, it showed improved maintenance of visual acuity as compared to placebo.
• It is also involved in maintaining a healthy lens of the eye. Lower levels of zinc have been shown to increase the risk of developing cataracts. (8)

Vitamin C

• Studies show ascorbic acid to protect the retina against light damage.
• Vitamin C has been shown to reduce the risk of UV-induced cataracts.
• It also helps in regenerating powerful antioxidants like Vitamin E, which in turn play a crucial role in eye health. (8)

Vitamin E

• Vitamin E in ocular health helps in the expression and activities of molecules and enzymes involved in the immune and inflammatory responses.
• Being one of the most powerful antioxidants it is responsible to prevent oxidative damage and plays an important role in maintaining a strong immune system in the eye. (8)

Vitamin D

• Several studies indicated that lower serum levels of 25(OH)D3 are associated with an increased risk of myopia also known as near-sightedness. (9)
• In a study, patients with aged-macular degeneration (AMD) were tested to have lower serum levels of 25(OH) D3. Higher serum vitamin D3 levels were shown to prevent the risk of AMD in certain populations.
• The deficiency of Vitamin D is correlated to early age-related cataract formation. (9)

Folate:

• Higher serum homocysteine levels- an amino acid was shown to increase the incidence of PSC posterior subcapsular cataract. Folate or vitamin B9 plays a vital role in the pathways that involve the breakdown of homocysteine. It helps lower the plasma homocysteine levels thus preventing its implications on eye health. (10)

1. Buscemi, S., Corleo, D., Di Pace, F., Petroni, M. L., Satriano, A., & Marchesini, G. (2018). The effect of lutein on eye and extra-eye health. Nutrients, 10(9), 1321.

2. Wilson, L. M., Tharmarajah, S., Jia, Y., Semba, R. D., Schaumberg, D. A., & Robinson, K. A. (2021). The Effect of Lutein/Zeaxanthin Intake on Human Macular Pigment Optical Density: A Systematic Review and Meta-Analysis. Advances in nutrition (Bethesda, Md.), 12(6), 2244–2254.

3. Mehkri, S., Thirumalesh, M. B., Krishnaiah, M. V., Ashok, G., & Bopanna, K. The effects of lutein and zeaxanthin (Lute-gen®) supplementation, with and without natural mixed carotenoids on macular pigment optical density in healthy adult subjects: A randomized, double-blind, placebo-controlled study.

4. Vaccinium myrtillus (Bilberry), Monograph. Alternative Medicine Review, Volume 6, Number 5, 2001

5. Riva, A., Togni, S., Franceschi, F., Kawada, S., Inaba, Y., Eggenhoffner, R., & Giacomelli, L. (2017). The effect of a natural, standardized bilberry extract (Mirtoselect®) in dry eye: a randomized, double blinded, placebo-controlled trial. Eur. Rev. Med. Pharmacol. Sci, 21(10), 2518-2525.

6. Manzi, F., Flood, V., Webb, K., & Mitchell, P. (2002). The intake of carotenoids in an older Australian population: The Blue Mountains Eye Study. Public Health Nutrition, 5(2), 347-352.

7. Rasmussen, H. M., & Johnson, E. J. (2013). Nutrients for the aging eye. Clinical interventions in aging, 8, 741–748. https://doi.org/10.2147/CIA.S45399

8. Brown, N. A. P., Bron, A. J., Harding, J. J., & Dewar, H. M. (1998). Nutrition supplements and the eye. Eye, 12(1), 127-133.

9. Chan, H. N., Zhang, X. J., Ling, X. T., Bui, C. H. T., Wang, Y. M., Ip, P., … & Pang, C. P. (2022). Vitamin D and Ocular Diseases: A Systematic Review. International Journal of Molecular Sciences, 23(8), 4226.

10. Tan, A. G., Mitchell, P., Rochtchina, E., Flood, V. M., Cumming, R. G., & Wang, J. J. (2015). Serum homocysteine, vitamin B12, and folate, and the prevalence and incidence of posterior subcapsular cataract. Investigative ophthalmology & visual science, 56(1), 216-220.