Glaucoma is a disorder that causes damage to important structures within the eye, primarily the optic nerve which is located at the back of the eye, connecting our retina to our brain. A healthy optic nerve is vital for good vision. The damage to the optic nerve in eyes with glaucoma is often the result of increased pressure inside the eye (intraocular pressure – IOP) caused by a buildup of fluid. As pressure inside the eye rises, over time it puts a strain on the optic nerve fibers leading to significant damage. It is not fully understood if the optic nerve damage occurs because of the mechanical compression of the nerve fibers from the increased pressure, or if the pressure restricts necessary blood flow to the optic nerve. As nerve fibers become damaged, they are unable to transmit light from the retina to the brain, meaning that blind spots may begin to occur in the field of vision.  

Although glaucoma cannot be cured, there are treatments available that can effectively manage the condition and prevent permanent vision loss, especially if treatment is started early.  

Glaucoma treatment tends to focus on reducing the pressure within the eye and maintaining at normal levels, which will reduce the likelihood of further damage to the optic nerve and loss of vision.  

Recent research evidence suggests a link between the amount of certain nutrients, primarily antioxidants, in our bodies and risk of glaucoma.

There are some risk factors for glaucoma that we can’t change, like our age, ethnicity or family history. Until recently, it was thought that reducing the pressure inside the eye was the only risk factor that could be modified to treat glaucoma, but recent research evidence suggests a link between the amount of certain nutrients, primarily antioxidants, in our bodies and risk of glaucoma. Studies have shown that antioxidant levels are lower in samples of both the blood serum and aqueous humor (the fluid inside the eye) of people with glaucoma. [2] Antioxidants play a vital role in our bodies to help prevent cellular damage from oxidative stress. They help to deactivate harmful free radicals which are atoms of oxygen that can damage cells within the body (oxidative damage and oxidative stress). Free radicals are unstable atoms that cause damage to healthy cells when they move through the body in search of an electron to make them more stable. Research has shown that the damage caused by free radicals can lead to increased risk of cancer, heart disease and eye disease.  

Oxidative stress can also directly contribute to cell death (retinal ganglion cells – the critical neurons that are damaged in glaucoma) in the inner retinal layers, which can be further compounded by elevated pressure inside the eye. Oxidative stress can cause damage to the cells of many important structures, tissues, and nerve cells in our eyes. In addition, oxidative stress also contributes to damaging cells in the trabecular meshwork which is the structure that is key to normal drainage of aqueous humor (fluid in the eye) and without normal drainage, fluid builds up and eye pressure increases. [15] 

Several studies have shown that a healthy diet, rich in fruits and vegetables high in antioxidants, is linked to reduced risk for glaucoma, especially in older adults that are already at an increased risk for developing glaucoma. [1, 9]

 

The 7 Best Natural Ingredients to Fight Glaucoma

1.  Niacinamide – Niacinamide is one of the two forms of vitamin B3 (the other is nicotinic acid). Niacinamide has been shown to have a protective effect on optic nerve cells that can become less active or functional as we age.  In a laboratory study in animals, researchers found that administering niacinamide boosted the metabolic reliability (normal cell activity and functioning) of aging retinal ganglion cells, keeping them healthier for longer. This is an important finding for glaucoma research because decreased levels of niacinamide were found to reduce the reliability of neurons’ energy metabolism, especially under stress such as increased intraocular pressure. Niacinamide has also been shown to help support mitochondria. The mitochondria of the optic nerve are the energy powerhouses of the optic nerve, and dysfunction of the mitochondria can make cells in the retina more susceptible to damage from elevated intraocular pressure. Niacinamide can help replenish levels of NAD which can help prevent damage to the retinal ganglion cells and help prevent glaucoma. Levels of nicotinamide adenine dinucleotide (NAD, a key molecule for mitochondrial health) are reduced in retinal ganglion cells with age. This reduction can make retinal ganglion cells susceptible to damage during periods of elevated intraocular pressure, and therefore, niacinamide can help replenish NAD levels and has promise for both preventing and treating glaucoma.  [13]

Bilberry –Bilberry fruit and its extract are powerhouses of good nutrition. Currently, bilberry fruit is used in jams and as a baking ingredient, but the concentrated extract is used in supplements to help manage circulation issues, disorders of the retina, glaucoma, and cataracts. The pharmacologically active ingredients of the bilberry are a group of compounds called anthocyanins (chemical compounds that give them their deep purple color), which have powerful antioxidant and anti-inflammatory action. Researchers have speculated that bilberry extract’s collagen stabilizing and biosynthesis abilities may provide some benefit to the structures in the eye responsible for aqueous (eye fluid) outflow that can be impaired in people with glaucoma, leading to pressure increases. One study evaluated patients that were given a single dose of bilberry extract and the results showed some benefits of bilberry extract for people with glaucoma. These patients showed some improvement in electroretinography testing, which measures the electrical response from the eye's light-sensitive cells, rods and cones. Similarly, a study of 132 glaucoma patients in Korea showed improved vision after taking bilberry extract supplements. [11]

Black Currants - Blackcurrants are packed with antioxidant, antibacterial, and antiviral properties. Research has shown that anthocyanin-rich blackcurrants may have the ability to inhibit multiple biological pathways in the retina to protect visual function. [8] The increased levels of antioxidant defense suppress the chemical reactions that cause inflammation in its early stages and reduce the occurrence of retinal cell death by having a tissue-protecting effect.  [12] Blackcurrants and their benefits in people with glaucoma have been studied extensively. Study results have shown that people who consumed 50mg of blackcurrants daily were found to have improved blood flow in their eye, a decrease in elevated intraocular pressure (pressure inside the eye), and reduced visual field loss compared to those that did not receive any blackcurrants. [3, 4, 5] These little berries have high levels of potassium, calcium, magnesium and iron and contain γ-linolenic acid, an essential polyunsaturated fatty acid.

Quercetin - Quercetin is a type of flavanol known for promoting healthy blood vessel function. Studies have shown that damage to the optic nerve in glaucoma may be linked to unstable perfusion of the optic nerve head and retina. In other words, that there are large fluctuations in blood flow and pressure which is another source of oxidative stress that may cause glaucoma damage. [10] Quercetin can be found in leafy vegetables, broccoli, red onions, peppers, apples, grapes, black tea, green tea, red wine, and some fruit juices. Research studies have also reported quercetin to have excellent antioxidative, anti-inflammatory, and anti-proliferative capabilities. Studies specific to retinal and macular healthy have shown that quercetin can also be protective of precious retinal pigment epithelial cells.  

Grape Seed - Grape seed extract is a potent antioxidant, so it helps prevent damage due to ongoing oxidative stress. In laboratory studies, grape seed extract has been shown to protect neurons and nerve cells, specifically retinal ganglion cells, against the damaging effects and cell death caused by oxidative stress. [14]

Coenzyme Q10 (CoQ10)  - Coenzyme Q10 is an antioxidant that is naturally produced in the body, but this production declines as we age. The cells in the body use CoQ10 for growth and maintenance and it has been studied as a potential protective agent for the retinal cells and neurons in glaucoma. A recent review of research related to CoQ10 and glaucoma concluded that there is an increasing evidence to support the potential beneficial effects of CoQ10 in protecting neuroretinal cells from oxidative damage and endorsed its potential use in glaucoma treatment. [7]

Saffron – Also a powerful antioxidant to help prevent damage from oxidative stress, but with scientific evidence that it can lower elevated pressure in the eye. In a clinical study, people with primary open angle glaucoma took daily oral supplements of saffron in addition to their prescribed eye drops (timolol 0.5% twice daily and dorzolamide 2% three times daily). After only three weeks, participants taking saffron experienced significant reductions in their intraocular pressure compared to those that were taking a placebo. [6]

Sometimes, getting enough of some important nutrients from our diets alone can be challenging. Many people consider adding a supplement to their daily routine to help to reach the recommended amount to meet their specific needs. It is important to carefully read product labels and confirm that the supplement is of the highest quality, from a reputable company, and contains appropriate nutrient amounts and no unwanted ingredients such as dyes or fillers.

When considering a nutritional supplement, it is always important to check with your physician or health care professional. 

 

References:

[1] Giaconi J.A., Yu F., Stone K.L., Pedula K.L., Ensrud K.E., Cauley J.A., Hochberg M.C., Coleman A.L. The association of consumption of fruits/vegetables with decreased risk of glaucoma among older African-American women in the study of osteoporotic fractures. Am. J. Ophthalmol. 2012;154:635–644 https://www.ncbi.nlm.nih.gov/pubmed/22818906

[2] Goyal A, Srivastava A, Sihota R, Kaur J. Evaluation of oxidative stress markers in aqueous humor of primary open angle glaucoma and primary angle closure glaucoma patients. Curr Eye Res. 2014 Aug; 39. https://www.ncbi.nlm.nih.gov/pubmed/24912005

[3] Hiroshi Ohguru, Ikuyo Ohguro, Maki Katai, Sachie Tanaka Two-year Randomized, Placebo Controlled Study of Blackcurrant Anthocyanins on Visual Field in Glaucoma. OPHTHALMOLOGICA 2012, 228:26-35

[4] Hiroshi Ohguru, Ikuyo Ohguro, Saeko Yagi Effects of Blackcurrant Anthocyanins on Intraocular Pressure in Healthy Volunteers and Patients with Glaucoma. JOURNAL OF OCULAR PHARMACOLOGY AND THERAPEUTICS 2013, Vol 29 No.1:61-67

[5] Ikuyo Ohguroll, Hiroshi Ohgurol, Mitsuru Nakazawa Effects of anthocyanins in black currant on retinal blood flow circulation of patients with normal tension glaucoma. A pilot study.  HIROSAKI MEDICAL ]OURNAL. 59: 23-32. 2007. https://hirosaki.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3602&item_no=1&attribute_id=20&file_no=1

[6] Jabbarpoor Bonyadi MH, Yazdani S, Saadat S. The ocular hypotensive effect of saffron extract in primary open angle glaucoma: a pilot study. BMC Complement Altern Med. 2014 Oct 15; 14():399. https://www.ncbi.nlm.nih.gov/pubmed/25319729

[7] Martucci A, Nucci C.  Evidence on neuroprotective properties of coenzyme Q10 in the treatment of glaucoma.  Neural Regen Res. 2019 Feb;14(2):197-200. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6301180/

[8] Miyake S, Takahashi N, Sasaki M, Kobayashi S, Tsubota K, Ozawa Y. Vision preservation during retinal inflammation by anthocyanin-rich bilberry extract: cellular and molecular mechanism. Lab Invest. 2012;92:102–9. https://www.ncbi.nlm.nih.gov/pubmed/21894150

[9] Moïse MM, Benjamin LM, Doris TM, Dalida KN, Augustin NO. Role of Mediterranean diet, tropical vegetables rich in antioxidants, and sunlight exposure in blindness, cataract and glaucoma among African type 2 diabetics. Int J Ophthalmol. 2012; 5(2):231-7. (8):823-9. https://www.ncbi.nlm.nih.gov/pubmed/22762057

[10] Nakazawa T. Ocular Blood Flow and Influencing Factors for Glaucoma. Asia Pac J Ophthalmol (Phila). 2016 Jan-Feb; 5(1):38-44. https://www.ncbi.nlm.nih.gov/pubmed/26886118

[11] Shim SH, Kim JM, Choi CY, Kim CY, Park KH. Ginkgo biloba extract and bilberry anthocyanins improve visual function in patients with normal tension glaucoma. J Med Food. 2012 Sep;15(9):818-23. https://www.ncbi.nlm.nih.gov/pubmed/22870951

[12] Wang Y, Zhao L, Lu F, Yang X, Deng Q, Ji B, Huang F.  Retinoprotective Effects of Bilberry Anthocyanins via Antioxidant, Anti-Inflammatory, and Anti-Apoptotic Mechanisms in a Visible Light-Induced Retinal Degeneration Model in Pigmented Rabbits. Molecules. 2015 Dec 14;20(12):22395-410. https://www.ncbi.nlm.nih.gov/pubmed/26694327

[13] Williams PA, Harder JM, Foxworth NE, Cochran KE, Philip VM, Porciatti V, Smithies O, John SW.  Vitamin B3 modulates mitochondrial vulnerability and prevents glaucoma in aged mice. Science. 2017 Feb 17;355(6326):756-760. https://www.ncbi.nlm.nih.gov/pubmed/28209901

[14] Yang H, Lee BK, Kook KH, Jung YS, Ahn J. Protective effect of grape seed extract against oxidative stress-induced cell death in a staurosporine-differentiated retinal ganglion cell line. Curr Eye Res. 2012 Apr;37(4):339-44. https://www.ncbi.nlm.nih.gov/pubmed/22440165

[15] Zhou L, Li Y, Yue BY. Oxidative stress affects cytoskeletal structure and cell-matrix interactions in cells from an ocular tissue: the trabecular meshwork. J Cell Physiol. 1999 Aug; 180(2):182-9. https://www.ncbi.nlm.nih.gov/pubmed/10395288