Dr. Grossman’s Blog

Lutein May Help Visual Contrast Sensitivity for Computer Users

Lutein is known to be an essential nutrient in helping prevent the onset of macular degeneration. Researchers now believe that lutein may also help protect against the detrimental effects of long-term computer display light exposure.

A study published in the British Journal of Nutrition indicates that improvements in the eye’s sensitivity to contrast on a computer screen were observed following 12 weeks of supplementation with lutein.

Scientists at the Peking University in China studied 37 healthy individuals aged 22 to 30 who had long-term computer display light exposure. Participants were randomly assigned to one of three groups: one group was given placebos, one group was given 6 milligrams of lutein daily, and one group was given 12 milligrams of lutein daily.

Levels of serum lutein and visual performance indices such as visual acuity, contrast sensitivity and glare sensitivity were measured at the beginning of the study and again at 12 weeks.

After 12 weeks researchers found an increase in blood levels of lutein in both lutein groups. The study authors noted: “Visual function in healthy subjects who received the lutein supplement improved, especially in contrast sensitivity, suggesting that a higher intake of lutein may have beneficial effects on the visual performance.”

Lutein can be found in green leafy vegetables and egg yolks. Learn about food sources for nutrients important to good eye health, including lutein.

Read other studies about the benefits of lutein for good eye health

SOURCE: “A 12-week lutein supplementation improves visual function in Chinese people with long-term computer display light exposure”, Ma, et al, British Journal of Nutrition, Published online by Cambridge University Press 19 Feb 2009 doi:10.1017/S0007114508163000.

Glaucoma is the result of damage to the optic nerve, often caused by increased pressure in the eye (“intraocular pressure”). This can happen when extra fluid builds up inside the eye (the eye makes too much fluid or does not drain well), and may happen after an eye injury, after eye surgery, or due to an eye tumor. Studies also indicate a possible link between heavy computer use and glaucoma, especially for computer users farsighted or nearsighted to begin with. Also, some medicines, such as corticosteroids used to treat other diseases may cause glaucoma.

Studies conducted at the University of Melbourne, Australia, in 2007 suggest that adding Omega-3 fatty acids to your diet can reduce the excessive intraocular pressure that causes most glaucoma.

In laboratory experiments groups of rats were raised on diets that contained sufficient or deficient amounts of omega-3 fatty acids. The omega-3 rich diet contained (in a 5.5/1/.5 ratio):

• Safflower oil
• Flaxseed oil
• Tuna oil

The omega-3 deficient diet contained:

• Safflower oil only

Those rats raised on high omega-3 diets had a 13% decrease in intraocular pressure at 40 weeks of age. This lower pressure in the omega-3-rich group was associated with an increase in aqueous humor outflow—that fluid occupying the space between the crystalline lens and the cornea of the eye—and a decrease in ocular rigidity.

These results suggest that increasing your intake of omega-3 fatty acids over time, can reduce intraocular pressures that may cause glaucoma.

Note: Glaucoma can be difficult to detect until a significant amount of vision is lost. Most individuals with undiagnosed glaucoma do not suffer any symptoms, not even a reduction in peripheral vision. Regular eye exams should be utilized to detect potential problems.

Read what others say about natural products that help glaucoma.

Resources:
Invest Ophthalmol Vis Sci. 2007 Feb; 48(2):756-62. Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia.

This week I’m going to start a series on glaucoma – I’ll cover these points in my next posts:

1. What is it? How does it manifest? Why is it caused? Symptoms?

2. What are the conventional treatment options? Do they work?

3. Are there any alternatives? Do they work? Is there research to back them up?

So – what is glaucoma!

Glaucoma is a truly insidious disease that can be difficult to detect until a significant amount of vision is lost. We are especially concerned about glaucoma because heavy computer users (ie 8 hours a day) have been found to have a higher risk for glaucoma, especially if they are nearsighted.

Glaucoma is often referred to as the “silent thief”, because most individuals with undiagnosed glaucoma do not suffer from any symptoms until they begin to notice a reduction in their peripheral vision.
Technically, glaucoma is due to damage to the optic nerve, sometimes as a result of increased pressure of the aqueous humor, the clear, watery fluid that circulates in the chamber of the eye between the cornea and the lens. But the term glaucoma is now defined as a collection of diseases that causes optic nerve damage. As a result, the diagnosis is no longer solely based on whether a person’s Intraocular Pressure (IOL) is elevated or not.

There are several types of glaucoma:

Open angle or Chronic Glaucoma

Narrow Angle Glaucoma – an ocular emergency

Low Tension Glaucoma

Secondary Glaucoma

Glaucoma Suspects

Congenital Glaucoma

Symptoms

• Reduced peripheral vision
• Intraocular pressure (IOP) greater than 21, or where there is a large discrepancy in IOP’s between the two eyes.
• Optic cup asymmetry

In short, nothing you would readily notice until the disease had significantly developed. This is why it is so important that you have your vision checked periodically – annually. One of the tests that your eye doctor will do is one for glaucoma.

Causes

• High level of stress – has been implicated as a major cause of chronic glaucoma. For example, stress causes us to breath shallowly, which reduces the amount of oxygen in the bloodstream, causing venous backflow in the head. This effects the eye’s ability to revolve eye fluids, which results in increased pressure. Although we do not know exactly how the optic nerve is damaged in glaucoma, one common factor in all cases of glaucoma is a lack of bloodflow to the retina and optic nerve. This results in retinal nerve cell death, enlargement of the optic cup, and loss of vision.
• Nutritional Deficiencies and Poor Digestion – Often sufferers of glaucoma are deficient in some or many of the important nutrients including essential fatty acids, lutein, zeaxanthin, taurine, antioxidants, bioflavenoids, zinc, selenium, vitamin B-complex.
• Poor digestion often results from a lack of hydrochloric acid in the stomach needed to breakdown food, which becomes more common as we age. Use of excessive antibiotics is also a prime culprit in poor digestion due to the killing of important stomach flora.
• Family History of Glaucoma
• Other chronic diseases that can raise IOP’s include obesity, diabetes, cardiovascular disease (insufficient blood flow to the eyes), thyroid disease (hyperthyroidism) which due to prominent eyes, the eyes are exposed to increased pressure from intraorbital swelling.
• Being African-American (glaucoma is the leading cause of blindness among this population)
• Extreme nearsightedness or farsightedness (higher level and a risk of angle closure)
• Steroid use, often in the form of eyedrops, nosedrops or inhalants (elevates IOL pressure mildly in approximately 16% of people on steroids).
• Heavy computer use – it is thought that heavy computer use can contribute to glaucoma, especially in those who are short-sighted.

Take Care!
Marc Grossman

I’m pleased to announce our new very short video – demonstrating 3 eye exercises especially useful for computer users with tired eyes and/or experiencing computer eye syndrome!

You can view it at YouTube.com.