Many of us assume that replenishing tears is all that’s needed to moisten eyes and that tears are simply salt water—saline. But that isn’t so. New research has confirmed what our experts have been telling you here at Daily Health News. Your eyes need more than a little watering to keep them moist—but it’s not hard to get the eye relief you long for.
PROTECT YOUR TEARS
If dry eyes are a problem for you, your best move may be to stop using the ineffective artificial-tear products you’ve been toting around. Eyes actually have a multipoint moisture defense system called the tear film. The outermost part of this film is a layer of lipids—an oily, fatty coating that lies over tears that coat the eye and keeps them from evaporating. And that, in part, is why saline-based eye moisteners and especially plain water often don’t bring lasting relief. Eye moisture is about the integrity of that lipid layer (a complex mix of lipids and other compounds)—not how much you try to replace tears.
A team of ophthalmologists from the University of South Wales School of Optometry and Vision Science in Sydney, Australia, illustrated this in a study that investigated the relationship between contact lens discomfort and damage to the lipid layer of the eye. They theorized that tears dry too quickly in people whose lipid layer has worn down and become imbalanced—a common problem in contact lens wearers. They compared two groups of contact wearers—those who reported that their lenses were comfortable and those who reported they weren’t.
All of the study participants were asked to wear soft hydrogel lenses for six hours. Then, the surface dryness of their eyes was measured and tear samples collected. Surface dryness was defined as how many seconds it took for a dry spot to appear on the eye before blinking.
The result: The eyes of the group who said that their contact lenses were uncomfortable went dry in half the time of the eyes of the group who reported no discomfort. Time for the first dry spot to appear after blinking was 4.5 seconds for the contact lens discomfort group versus 10 seconds for the no-discomfort group—a big difference when multiplied by a full day of comfort or discomfort.
Next, the team took those participants with dry-eye problems and treated the eyes of half with a liposomal spray, made of lipids found naturally in tear film, and the other half with a saline spray. The same experiment was repeated two days later, but the group that first received the liposomal spray received the saline spray this time and vice versa. As predicted, when eyes were treated with the liposomal spray, they stayed moist and comfortable longer. Even two hours after treatment, the liposomal spray kept eyes moist between blinks an average of 13% longer than the saline spray.
PROTECT YOUR EYES
Eyes have to be moist to retain comfort, maintain clear vision and be protected from infection. As discussed in another Bottom Line article, one of the simplest defenses against dry eyes is blinking. Every time you blink, you wash your eyes with a fresh layer of tears and lipids and clear away debris. So be sure to consciously blink and rest your eyes from time to time by looking away from the computer screen or whatever you’ve been focusing on—even if you have to set a timer to do so. Also keep your eyes moist with lipids from the inside out by eating foods containing healthful fats, such as fish, or consider a fish oil supplement. And, as suggested by the study findings, instead of plain saline, it may help to opt for eye-moistening products labeled “liposomal.” The liposomal spray used in the Australian study was Tears Again, manufactured by BioRevive. That particular product is not available in the US, but you can find similar liposomal eye sprays here. (The researchers had no relationship with BioRevive and did not receive financial support from it for the study.)
Study titled "Clinical and Biochemical Tear Lipid Parameters in Contact Lens Wearers," from the School of Optometry and Vision Science at the University of New South Wales in Sydney, Australia, published in Optometry and Vision Science.Date: February 12, 015 Publication: Daily Health News