Eyesight: How to protect your eyesight as you age

When your eyes follow these words across the computer screen, are there threadlike elements in your field of vision that tag along, sliding back and forth with the movement of your eyes?

Those are known as floaters, and an HSI member named Frank has this question about them: 'When will there be an e-alert on Floaters in the eyes and what can be done to protect sight?'

The answer to 'When?' is: You're reading it right now. And to start things off, I've got good new and bad news about floaters...and some additional good news. The good news: Most floaters develop as a natural part of ageing. The bad news: There's no treatment for them. But the additional good news is: Eventually they'll go away (or at least they'll be minimized).

Floaters debris inside the eye
The vitreous is a gel-like material inside the eyeball that helps maintain the spherical shape of the eye. As we age, the vitreous begins to shrink slightly, sometimes causing small strands to thicken into spots or threadlike webs that cast faint shadows on the retina. Floaters may appear to be debris on the surface of the eye, but they're actually shadows of debris inside the eye.

The development of floaters can also be prompted by diabetes, cataract operations, laser surgery or an injury to the eye. In most cases, they will eventually settle to the bottom of the eye where they're less likely to cast shadows on the field of vision. In other words, floaters take care of themselves.

More troubling is when a new batch suddenly appears, accompanied by flashes of light or a slight loss of peripheral vision. These are signals of a possible retinal detachment or diabetic retinopathy, both of which are very serious problems that should be addressed immediately. If not treated quickly, these conditions can lead to permanent impairment and even blindness.

Although they may be annoying, they don't present a serious risk to vision health. But in rare cases they may be thick or clustered enough to interfere with eyesight. In advanced cases like this, a surgical procedure called vitrectomy is an option. This procedure is generally not recommended because it risks damage to the retina.

Antioxidant lineup to protect your eyesight
Frank also had a question about how to protect eyesight; a topic we've addressed often in the e-alerts.

In the e-alert 'How to ward off AMD and retain your sight' (4/12/03), I told you about an American study by the National Eye Institute (NEI) on the prevention of age-related macular degeneration (AMD); a common disorder of the retina. In this eight-year study that involved more than 3,500 subjects over the age of 55, researchers found that when administered in the early stage of AMD, certain supplements significantly inhibited the total amount of vision loss that would normally be caused by the condition.

The research team recommended that anyone at risk of developing AMD should consider taking these supplements daily, in the same amounts used in the study:

* Vitamin C - 500 mg
* Vitamin E - 400 IU
* Beta-carotene - 15 mg
* Zinc (as zinc oxide) - 80 mg
* Copper (as cupric oxide) - 2 mg

Chasing the clouds away
Cataracts are another major concern especially for people over the age of 75.

In a past e-alert I looked at research from Tufts University that examined the effects of specific nutrients in preventing the oxidation damage that contributes to the formation of cataracts. The Tufts team examined 13 years of nutrition and medical data collected from nearly 500 women over the age of 50.

Researchers found that women with the lowest amount of lens-clouding opacification, also had the highest intake of these antioxidant nutrients: lutein, zeaxanthin, folate, beta carotene, riboflavin and vitamins C and E. Women who had taken daily vitamin C supplements for more than a decade were 64 percent less likely to show signs of the opacification that leads to cataracts than the women who took no vitamin C supplements at all.

Lutein and zeaxanthin are carotenoids that are key components of a phytochemical called xanthophylls. Good food sources of xanthophylls include corn, kiwi, red seedless grapes, orange-colored peppers, spinach, celery, Brussel sprouts, scallions, broccoli, and squash.