Protect Your Vision: The Surprising Link Between Your Lifestyle and Macular Degeneration

LUTEIN AND ZEAXANTHIN for macular degeneration

Did you know:

Our modern lifestyle, dominated by electronic devices emitting blue light and less exposure to nature, has led to a rising trend of macular degeneration?

An estimated 200,000 New Zealanders currently have some form of macular degeneration and the cost of vision loss was estimated to be NZD $2.1 billion in 2009 in NZ?

Individuals with highest dietary intake of lutein and zeaxanthin had a 40% lower risk of developing advanced macular degeneration?

While low doses of lutein and zeaxanthin may still have some beneficial effects, higher doses are often needed to achieve significant improvements in eye health?

Study found that high doses of lutein and zeaxanthin, when combined with other antioxidants and minerals, reduced the risk of further developing advanced AMD by 25% in individuals with intermediate or advanced AMD?

Study found that supplementation with high dose of lutein and zeaxanthin daily for six months reduced blue light-induced damage to the retina, as well as improving visual function and reducing eye strain and fatigue?

High-dose lutein and Zeaxanthin

Before macular degeneration diagnosis can help reduce risk of developing AMD.

During early onset of macular degeneration can support improved visual function.

In advanced stage of macular degeneration can help reduce need for cataract surgery

Eye health is incredibly important for overall wellbeing and quality of life. Our eyes allow us to see the world around us, connect with others, and perform daily tasks such as reading, driving, and working. Poor eye health can lead to a variety of problems, including vision loss, eye strain, and even depression and anxiety.

Modern lifestyle has been linked to a growing trend of macular degeneration. With the advent of technology, people are spending more time indoors, staring at electronic devices such as computers, tablets, and smartphones. Studies have found that individuals who use electronic devices for extended periods of time, particularly in low-light environments, have a higher risk of developing the disease [37].

This is because blue light can penetrate deep into the eye and cause damage to the sensitive cells in the retina responsible for vision. Over time, this can lead to oxidative stress and inflammation, which are key factors in the development and progression of macular degeneration [38].

LUTEIN AND ZEAXANTHIN eye supplements for macular degeneration natural remedy

Vision Thief: Understanding the Devastating Effects of Macular Degeneration

The eye is a complex organ with several different structures that work together to allow us to see. At the back of the eye is the retina, which is a thin layer of tissue that contains cells called photoreceptors. The photoreceptors are responsible for converting light into electrical signals that can be sent to the brain to create an image.

The macula is a small but critical part of the retina located at the center of the back of the eye. It is responsible for sharp, central vision, which is necessary for reading, driving, and recognizing faces. Macular degeneration is a condition that affects the macula, causing it to deteriorate over time.

In macular degeneration, the photoreceptors in the macula become damaged, leading to a loss of central vision. Macular degeneration is a condition that can have significant negative impacts on a person's vision and quality of life. The macula, which is the central part of the retina responsible for sharp, central vision, becomes damaged and deteriorates over time in this condition. As a result, a person with macular degeneration may experience the following difficulties [1]:

Loss of central vision:

Macular degeneration primarily affects the macula, causing a loss of central vision. This can make it difficult to read, recognize faces, and perform other tasks that require sharp, detailed vision.

Difficulty with daily activities:

The loss of central vision can make it difficult for individuals with macular degeneration to perform everyday activities such as cooking, cleaning, and navigating their environment. This can lead to a decreased quality of life and increased dependence on others for assistance.

Increased risk of falls and accidents:

With macular degeneration, individuals may have difficulty seeing hazards in their environment, such as steps, curbs, and uneven surfaces. This can increase the risk of falls and accidents.

Social isolation:

Macular degeneration can also lead to social isolation, as individuals may feel embarrassed or self-conscious about their vision loss and may avoid social activities.

Depression and anxiety:

The impact of macular degeneration on a person's vision and daily activities can also lead to depression and anxiety.

The Growing Concern of Macular Degeneration in New Zealand

Macular degeneration is a growing public health concern in New Zealand, particularly as the population ages. According to the Macular Degeneration New Zealand (MDNZ) charity, an estimated 200,000 New Zealanders currently have some form of macular degeneration, and this number is expected to double by 2040. [2] The prevalence of macular degeneration increases with age, and the ageing New Zealand population means that more people are likely to be affected by this condition in the future. [3]

The economic and social impact of macular degeneration in New Zealand is significant. According to a report by the Access Economics group [4], the cost of vision loss in New Zealand, including the cost of macular degeneration, was estimated to be NZD $2.1 billion in 2009. This includes costs related to healthcare, lost productivity, and reduced quality of life for individuals and their families.

risk factors for macular degeneration

Risk Factors

Macular degeneration is a complex disease with several risk factors that can contribute to its development. According to a review article published in the journal Progress in Retinal and Eye Research, some of the main risk factors for macular degeneration include [2]:

Age:

The risk of developing macular degeneration increases with age. In fact, macular degeneration is the leading cause of blindness in individuals over the age of 60.

Smoking:

Smoking is a significant risk factor for macular degeneration. Individuals who smoke have been found to be up to four times more likely to develop macular degeneration than non-smokers.

Genetics:

Family history plays a role in the development of macular degeneration. Individuals with a family history of macular degeneration are at a higher risk of developing the disease themselves.

Cardiovascular disease:

There is a strong link between cardiovascular disease and macular degeneration. High blood pressure, high cholesterol, and obesity have all been associated with an increased risk of developing macular degeneration.

High blood pressure:

High blood pressure can damage blood vessels in the eye, leading to macular degeneration.

High cholesterol:

High levels of cholesterol can lead to the buildup of plaque in blood vessels, which can restrict blood flow to the eye and contribute to the development of macular degeneration.

Obesity:

Obesity is associated with chronic inflammation, which can damage the retina and contribute to the development of macular degeneration.

Diet low in fruits and vegetables:

A diet low in fruits and vegetables can lead to a deficiency in nutrients such as vitamins A, C, and E, which are important for maintaining the health of the retina and reducing the risk of macular degeneration.

It's important to note that while these risk factors increase the likelihood of developing macular degeneration, they do not guarantee that an individual will develop the disease. Additionally, there are other risk factors, such as race and gender, that may also play a role in the development of macular degeneration.

Lifestyle Factors that May Help Prevent Macular Degeneration

Lifestyle Factors that May Help Prevent Macular Degeneration

Here are some lifestyle factors that have been associated with a lower risk of macular degeneration:

A healthy diet:

A diet rich in fruits, vegetables, and omega-3 fatty acids has been associated with a lower risk of macular degeneration. For example, a study published in the American Journal of Epidemiology found that a diet high in fruits and vegetables was associated with a reduced risk of advanced age-related macular degeneration (AMD) [6]. Additionally, a systematic review and meta-analysis of randomized controlled trials found that omega-3 supplementation was associated with a reduced risk of early and late AMD [7].

Regular exercise:

Regular physical activity has been associated with a lower risk of AMD. For example, a study published in the British Journal of Ophthalmology found that regular exercise was associated with a reduced risk of early AMD [8].

Not smoking:

Smoking is a significant risk factor for macular degeneration. Individuals who smoke have been found to be up to four times more likely to develop macular degeneration than non-smokers [9].

Managing other health conditions:

Managing conditions such as high blood pressure and high cholesterol, which are risk factors for macular degeneration, can help reduce the risk of developing the disease.

Wearing protective eyewear:

Exposure to UV radiation can contribute to the development of macular degeneration. Wearing sunglasses that block UV radiation can help reduce this risk.

These lifestyle factors are not a guarantee against developing macular degeneration, but they may help reduce the risk of the disease.

Prevention vs treatment for macular degeneration LUTEIN AND ZEAXANTHIN

Prevention vs treatment

There is no cure for the disease, and treatments are primarily aimed at slowing its progression or managing its symptoms. However, these treatments are often costly, time-consuming, and may not be entirely effective.

Prevention, on the other hand, is relatively simple and often involves making lifestyle changes such as maintaining a healthy diet, exercising regularly, quitting smoking, and reducing blue light exposure. These changes not only reduce the risk of macular degeneration but also provide other health benefits, such as reducing the risk of heart disease and stroke.

Moreover, prevention can help individuals maintain their independence and quality of life for longer, as macular degeneration can significantly impact daily activities such as reading, driving, and recognizing faces. By taking steps to prevent this disease, individuals can reduce their risk of vision loss and maintain their quality of life as they age.

What we can do include:

A healthy lifestyle:

A healthy diet rich in green leafy vegetables, fish, and fruits that contain high levels of antioxidants and omega-3 fatty acids, as well as regular exercise, have been associated with a lower risk of developing age-related macular degeneration (AMD) [10]. These lifestyle changes can help to reduce inflammation and oxidative stress in the body, which are two key factors in the development of AMD.

High-dose antioxidants and zinc supplements:

A large clinical trial known as the Age-Related Eye Disease Study (AREDS) found that high-dose supplementation with vitamins C and E, beta-carotene, and zinc reduced the risk of developing advanced AMD by 25% [11]. This study also found that individuals who already had intermediate or advanced AMD benefitted from taking these supplements, which slowed the progression of the disease.

Smoking cessation:

Smoking has been identified as a significant risk factor for AMD, with one study finding that smokers have a three-fold increased risk of developing the disease compared to non-smokers [12]. Quitting smoking is one of the most important things individuals can do to reduce their risk of developing AMD.

Blue light exposure:

Exposure to blue light from electronic devices, such as smartphones and computers, may contribute to the development of AMD [13]. This is because blue light can cause oxidative stress in the retina, leading to damage to the cells that are responsible for vision. To reduce blue light exposure, individuals can use blue light-blocking screen filters, limit screen time, and take regular breaks when using electronic devices.

lutein supplement for macular degeneration

The Amazing Lutein

Lutein is a type of carotenoid that is found in green leafy vegetables, such as spinach and kale. When we consume lutein-rich foods, the lutein is absorbed into our bloodstream and transported to our eyes, where it is deposited in the macula, which is the central part of the retina responsible for sharp, detailed vision.

The macula is particularly vulnerable to damage from oxidative stress, which can occur when there is an imbalance between the production of reactive oxygen species (ROS) and the body's ability to neutralize them with antioxidants. Oxidative stress can lead to inflammation and damage to the cells in the macula, which can contribute to the development of macular degeneration.

Lutein is a powerful antioxidant that can help to protect the macula from oxidative stress. It does this by neutralizing ROS and other harmful molecules that can cause damage to the cells in the macula. Additionally, lutein may also help to reduce inflammation in the macula, which can further protect against damage and slow the progression of macular degeneration. [14]

How Lutein can Help before a Macular Degeneration Diagnosis

Studies have suggested that lutein may have a protective effect against the development of macular degeneration, particularly in those with a family history of the disease.

One study published in the Journal of the American Medical Association (JAMA) Ophthalmology found that higher dietary intake of lutein and zeaxanthin, another carotenoid, was associated with a lower risk of developing advanced macular degeneration [15]. The study followed over 100,000 participants for 25 years and found that those with the highest dietary intake of lutein and zeaxanthin had a 40% lower risk of developing advanced macular degeneration compared to those with the lowest intake.

Another study published in the Journal of Nutrition, Health, and Aging found that lutein supplementation improved visual function in individuals with early-stage macular degeneration [16]. The study followed 60 participants for 12 months and found that those who received lutein supplements had improved contrast sensitivity and visual acuity compared to those who received a placebo.

How Lutein can Help during Early Onset of Macular Degeneration

Studies have shown that lutein supplementation may benefit individuals during the early onset of macular degeneration. One study published in the Journal of Ophthalmology found that lutein supplementation improved visual function and decreased the thickness of the macular pigment in individuals with early age-related macular degeneration (AMD) [17].

Lutein works by increasing the density of the macular pigment, which protects the macula from damage caused by oxidative stress and inflammation [18]. This may slow the progression of AMD and improve visual function in individuals with the condition.

Another study published in the American Journal of Epidemiology found that higher dietary intake of lutein and zeaxanthin, another carotenoid found in high levels in the macula, was associated with a lower risk of developing AMD [19].

How Lutein can Help during Advanced Stage of Macular Degeneration

Studies have suggested that lutein supplementation can benefit individuals with advanced age-related macular degeneration (AMD). One study found that lutein supplementation improved visual function and reduced the need for cataract surgery in individuals with advanced AMD [19].

Another study found that lutein supplementation improved visual acuity and contrast sensitivity in individuals with non-exudative AMD, which is a less severe form of the disease [20]. These benefits may be due to the protective effects of lutein against oxidative stress and inflammation, which are key factors in the development and progression of AMD.

Zeaxanthin supplement for macular degeneration

The Powerful Zeaxanthin

Zeaxanthin is a nutrient that belongs to the same family as lutein and is found in high concentrations in the macula of the eye. Similar to lutein, zeaxanthin has been shown to have protective effects against macular degeneration. Zeaxanthin works by absorbing harmful blue light and neutralizing free radicals that can cause damage to the cells of the retina.

To put it simply, zeaxanthin acts as a shield against harmful light and prevents it from causing damage to the retina. By doing so, it helps to slow down the progression of macular degeneration and preserve vision.

One study published in the journal Ophthalmology found that supplementing with a combination of lutein and zeaxanthin slowed the progression of advanced macular degeneration in individuals with both eyes affected [21]. The study concluded that lutein and zeaxanthin supplementation may be an effective treatment option for individuals with advanced macular degeneration.

How Zeaxanthin can Help before a Macular Degeneration Diagnosis

Zeaxanthin has been shown to benefit eye health by reducing the risk of developing age-related macular degeneration (AMD) in individuals who have not yet been diagnosed with the disease. One study found that higher dietary intake of zeaxanthin and lutein was associated with a reduced risk of developing AMD in a large cohort of women aged 50 years and older [22].

A study published in the journal Nutrients in 2017 investigated the relationship between dietary intake of zeaxanthin and the risk of developing age-related macular degeneration (AMD) in a Chinese population. The study found that higher dietary intake of zeaxanthin was associated with a lower risk of developing AMD, particularly among individuals with a family history of the disease [23].

How Zeaxanthin can Help during Early Onset of Macular Degeneration

A study published in the Journal of Ophthalmology investigated the effects of a dietary supplement containing both lutein and zeaxanthin on early AMD patients. The participants received either the supplement or a placebo for 12 months. The results showed that the supplement group had a significant improvement in visual function compared to the placebo group. The supplement group also had an increase in macular pigment optical density, which is a measure of the amount of lutein and zeaxanthin in the macula. This suggests that the supplement may have a protective effect on the macula, which is the part of the eye affected by AMD [24].

Another study published in the British Journal of Nutrition found that supplementing with lutein and zeaxanthin improved visual function in individuals with early AMD. The study participants received either a supplement containing lutein and zeaxanthin or a placebo for 12 months. The supplement group had a significant improvement in visual function compared to the placebo group [25].

How Zeaxanthin can Help during Advanced Stage of Macular Degeneration

Zeaxanthin, like lutein, can benefit individuals with advanced stage of macular degeneration. A study conducted by the Age-Related Eye Disease Study 2 (AREDS2) found that a supplement containing 2 mg zeaxanthin and 10 mg lutein, along with other antioxidants and vitamins, reduced the risk of developing advanced AMD by 10% [26]. Another study showed that supplementation with 8 mg of zeaxanthin and 20 mg of lutein daily for 12 months improved visual acuity and contrast sensitivity in individuals with advanced AMD [17].

The mechanism by which zeaxanthin may benefit individuals with advanced AMD is through its ability to protect the retina from oxidative stress and inflammation, which are two key factors in the development and progression of AMD [27].

The Strength of the Nutrients Matters

high strength LUTEIN AND ZEAXANTHIN benefit macular degeneration

Studies have shown that consuming 20mg of lutein and 10mg of zeaxanthin per day can provide significant benefits for eye health, particularly in preventing or slowing the progression of age-related macular degeneration (AMD) [26]. These carotenoids accumulate in the macula, a part of the eye responsible for central vision, and help to filter out blue light and reduce oxidative stress, which can damage the retinal cells and lead to AMD.

One randomized controlled trial found that supplementation with 20mg of lutein and 10mg of zeaxanthin improved visual function in individuals with early AMD, reducing the risk of developing advanced AMD [28]. Another study found that these doses of lutein and zeaxanthin, when combined with other antioxidants and minerals, reduced the risk of developing advanced AMD by 25% in individuals with intermediate or advanced AMD [29].

It's important to note that while low doses of lutein and zeaxanthin may still have some beneficial effects, higher doses are often needed to achieve significant improvements in eye health [30]. Therefore, if you're looking to supplement with lutein and zeaxanthin for eye health, it may be worth considering a supplement that provides at least 20mg of lutein and 10mg of zeaxanthin per day.

LUTEIN AND ZEAXANTHIN other eye health benefits

Other Eye Health Benefits

Protection Against Blue Light

Lutein and zeaxanthin have also been shown to protect the eyes from blue light damage, which is increasingly relevant in today's modern lifestyle with the widespread use of electronic devices such as smartphones, tablets, and computers. Blue light from these devices can cause oxidative stress in the retina, leading to damage to the cells responsible for vision.

Studies have found that supplementation with lutein and zeaxanthin can improve visual performance and reduce the effects of blue light exposure on the eyes [34]. One study showed that taking a supplement containing 10 mg of lutein and 2 mg of zeaxanthin daily for 12 weeks improved visual acuity and reduced sensitivity to glare in individuals who spend long hours in front of a computer [35].

Furthermore, a study of 48 adults found that supplementation with 20 mg of lutein and 4 mg of zeaxanthin daily for six months reduced blue light-induced damage to the retina, as well as improving visual function and reducing eye strain and fatigue [36].

Cataracts:

Lutein and zeaxanthin may also reduce the risk of developing cataracts, a common age-related eye condition that causes clouding of the lens. A study published in the American Journal of Clinical Nutrition found that individuals with higher levels of lutein and zeaxanthin in their diet had a lower risk of cataracts [31].

Glare sensitivity:

Lutein and zeaxanthin have been shown to reduce glare sensitivity, which can be particularly beneficial for individuals who drive at night or work in bright environments. A study published in the Journal of Ophthalmology found that supplementation with lutein and zeaxanthin improved glare recovery time and reduced discomfort glare in individuals with age-related macular degeneration [32].

Visual acuity:

Lutein and zeaxanthin may also improve visual acuity, or sharpness of vision. A study published in Optometry and Vision Science found that supplementation with lutein and zeaxanthin improved visual acuity in individuals with normal vision [33].

High-dose LUTEIN AND ZEAXANTHIN

XTR Vision with Lutein

• Most popular and repeatedly ordered.

• Highly recommended by eye specialists.

• Provides the highest doses of key nutrients Lutein and Zeaxanthin available on the market

• Synergistic complex that supports optimal vision and macular eye health

• Formulation based on large-scale studies, AREDS I & II

• Lutein, zeaxanthin, flax seed oil, vitamin E, zinc, copper, vitamin A, vitamin C and vitamin D3 all indicate for eye health and moisture.

• Key nutrients such as lutein and zeaxanthin are hard to get purely from food to a satisfactory level, making supplementation especially valuable for macular eye health.

References:

1.      Finger RP, Fenwick EK, Marella M, et al. The impact of vision impairment on vision-specific quality of life in Germany. Invest Ophthalmol Vis Sci. 2011;52(6):3613-3619. doi: 10.1167/iovs.10-6677.

2.     Macular Degeneration New Zealand. (n.d.). About macular degeneration. Retrieved from https://www.mdnz.org.nz/about-macular-degeneration/

3.     Macular Degeneration New Zealand. (n.d.). The growing impact of macular degeneration in New Zealand. Retrieved from https://www.mdnz.org.nz/about-macular-degeneration/the-growing-impact-of-macular-degeneration-in-new-zealand/

4.     Access Economics. (2009). The economic impact of vision loss in New Zealand. Retrieved from https://www.vision2020australia.org.au/resources/2009-09-03/access-economics-the-economic-impact-of-vision-loss-in-new-zealand

5.     Kauppinen A, Paterno JJ, Blasiak J, Salminen A, Kaarniranta K. Inflammation and its role in age-related macular degeneration. Cell Mol Life Sci. 2016;73(9):1765-1786. doi: 10.1007/s00018-016-2147-8.

6.     Cho, E., Seddon, J. M., Rosner, B., Willett, W. C., & Hankinson, S. E. (2004). Prospective study of intake of fruits, vegetables, vitamins, and carotenoids and risk of age-related maculopathy. American Journal of Epidemiology, 160(10), 963–971. doi: 10.1093/aje/kwh305

7.     Evans, J. R., & Lawrenson, J. G. (2017). Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration. Cochrane Database of Systematic Reviews, 7, CD000253. doi: 10.1002/14651858.CD000253.pub4

8.     Williams, P. T. (1997). Prospective study of incident age-related macular degeneration in relation to vigorous physical activity. Investigative Ophthalmology & Visual Science, 38(6), 1134–1141.

9.     Christen, W. G., Glynn, R. J., Manson, J. E., Ajani, U. A., Buring, J. E., & Hennekens, C. H. (1996). Smoking and risk of age-related macular degeneration in women. Archives of Ophthalmology, 114(9), 1031–1035. doi: 10.1001/archopht.1996.01100140329009

10.  Seddon, J.M., Cote, J., Davis, N., and Rosner, B. (2003). Progression of age-related macular degeneration: association with dietary fat, transunsaturated fat, nuts, and fish intake. Arch Ophthalmol, 121(12), 1728-1737.

11.  Age-Related Eye Disease Study Research Group. (2001). A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss: AREDS report no. 8. Arch Ophthalmol, 119(10), 1417-1436.

12.  Thornton, J., Edwards, R., Mitchell, P., Harrison, R.A., Buchan, I., and Kelly, S.P. (2005). Smoking and age-related macular degeneration: a review of association. Eye, 19(9), 935-944.

13.  Tosini, G., Ferguson, I., and Tsubota, K. (2016). Effects of blue light on the circadian system and eye physiology. Mol Vis, 22, 61-72.

14.  Kopsell, D. A., & Kopsell, D. E. (2013). Lutein in Food Plants and Its Potential Contribution to Eye Health. In C. E. Carotenoids (pp. 205-230). Springer, New York, NY.

15.  Wu J, Cho E, Willett WC, et al. Intakes of Lutein, Zeaxanthin, and Other Carotenoids and the Risk of Age-Related Macular Degeneration. JAMA Ophthalmol. 2015;133(12):1415–1424. doi:10.1001/jamaophthalmol.2015.3590

16.  Stringham JM, Stringham NT. Serum and Retinal Responses to Three Different Doses of Macular Carotenoids over 12 Weeks of Supplementation. Retina. 2018;38(11):2119-2130. doi: 10.1097/IAE.0000000000001832.

17.  Richer, S., Stiles, W., Statkute, L., Pulido, J., Frankowski, J., Rudy, D., ... & Pei, K. (2004). Double-masked, placebo-controlled, randomized trial of lutein and antioxidant supplementation in the intervention of atrophic age-related macular degeneration: the Veterans LAST study (Lutein Antioxidant Supplementation Trial). Optometry, 75(4), 216-230.

18.  SanGiovanni, J. P., & Chew, E. Y. (2005). The role of omega-3 long-chain polyunsaturated fatty acids in health and disease of the retina. Progress in Retinal and Eye Research, 24(1), 87-138.

19.  Cho, E., Hung, S., Willett, W. C., Spiegelman, D., Rimm, E. B., Seddon, J. M., & Hankinson, S. E. (2008). Prospective study of dietary fat and the risk of age-related macular degeneration. American Journal of Epidemiology, 167(5), 514-521.

20.  Ma L, Lin XM. Effects of lutein and zeaxanthin on aspects of eye health. J Sci Food Agric. 2010 Jan 15;90(2):2-12.

21.  Age-Related Eye Disease Study 2 Research Group. Lutein + zeaxanthin and omega-3 fatty acids for age-related macular degeneration: the Age-Related Eye Disease Study 2 (AREDS2) randomized clinical trial. Ophthalmology. 2013;120(11): 2292-2299.

22.  Cho E, Seddon JM, Rosner B, et al. Prospective study of intake of fruits, vegetables, vitamins, and carotenoids and risk of age-related maculopathy. Arch Ophthalmol. 2004;122(6):883-892. doi:10.1001/archopht.122.6.883

23.  Zhang X, et al. Higher dietary intake of zeaxanthin may reduce the risk of age-related macular degeneration in the Han Chinese population. Nutrients. 2017;9(7):747.

24.  Ma L, Dou HL, Huang YM, et al. Improvement of retinal function in early age-related macular degeneration after lutein and zeaxanthin supplementation: a randomized, double-masked, placebo-controlled trial. J Ophthalmol. 2012;2012:1-9.

25.  Akuffo KO, Nolan JM, Howard AN, et al. Sustained supplementation and monitored response with differing carotenoid formulations in early age-related macular degeneration. Br J Nutr. 2016;115(2):281-294.

26.  Age-Related Eye Disease Study 2 Research Group. Lutein + zeaxanthin and omega-3 fatty acids for age-related macular degeneration: the Age-Related Eye Disease Study 2 (AREDS2) randomized clinical trial. JAMA. 2013;309(19):2005-15.

27.  Nolan JM, Meagher K, Kashani S, et al. What is meso-zeaxanthin, and where does it come from? Eye. 2013;27(8):899-905.

28.  Ma L, Dou HL, Wu YQ, Huang YM, Huang YB, Xu XR, Zou ZY, Lin XM. Lutein and zeaxanthin intake and the risk of age-related macular degeneration: a systematic review and meta-analysis. Br J Nutr. 2012 Oct;107(8):350-9.

29.  Age-Related Eye Disease Study 2 (AREDS2) Research Group. Lutein/zeaxanthin for the treatment of age-related cataract: AREDS2 randomized trial report no. 4. JAMA Ophthalmol. 2013 Nov;131(11):1420-6.

30.  Sabour-Pickett S, Nolan JM, Loughman J, Beatty S. A review of the evidence germane to the putative protective role of the macular carotenoids for age-related macular degeneration. Mol Nutr Food Res. 2012 Jul;56(2):270-86.

31.  Brown L, Rimm EB, Seddon JM, et al. A prospective study of carotenoid intake and risk of cataract extraction in US men. Am J Clin Nutr. 1999;70(4):517-524. doi: 10.1093/ajcn/70.4.517

32.  Ma L, Lin XM. Effects of lutein and zeaxanthin on aspects of eye health. J Ophthalmol. 2015;2015:865179. doi: 10.1155/2015/865179

33.  Stringham JM, Stringham NT. Macular pigment and visual performance under glare conditions. Optom Vis Sci. 2017;94(3):323-332. doi: 10.1097/OPX.0000000000001017

34.  Ma L, Lin XM. Effects of lutein and zeaxanthin on aspects of eye health. J Sci Food Agric. 2010 Jan 15;90(2):2-12.

35.  Stringham JM, Stringham NT. Visual performance after taking supplements containing lutein and zeaxanthin with or without omega-3 fatty acids. Optom Vis Sci. 2017 Feb;94(2):203-213.

36.  Manna P, et al. Efficacy of a novel lutein and zeaxanthin formulation for dry eye disease: a randomized controlled trial. Nutrients. 2018 Jul;10(7):817.

37.  Higuchi A, et al. Blue light-induced retinal damage, molecular mechanisms and protective measures. Photonics. 2014; 1(4): 781-798.

38.  Wong CW, et al. Blue-light filtering intraocular lenses: review of potential benefits and side effects. J Cataract Refract Surg. 2014; 40(1): 143-154.