Nav: Home

Caffeine use may offer relief for millions of dry eye sufferers

April 17, 2012

SAN FRANCISCO - April 17, 2012 - Researchers at the University of Tokyo's School of Medicine have shown for the first time that caffeine intake can significantly increase the eye's ability to produce tears, a finding that could improve treatment of dry eye syndrome. This common eye condition affects about four million people age 50 and older in the United States. For many, dry eye syndrome is simply uncomfortable and annoying, but for others it escalates into a vision-threatening disease. All of the 78 participants in the new study produced significantly more tears after consuming caffeine than after taking a placebo. The study is available in Ophthalmology, the journal of the American Academy of Ophthalmology.

Dry eye syndrome involves malfunction of the rate of tear production, the quality of tears, and/or the rate of evaporate from the surface of the eye. Anyone can experience dry eye, though it is more common among women. Symptoms can include gritty, scratchy or burning sensations, excessive tearing, and/or production of stringy mucus.

The research team, by Reiko Arita, MD, PhD, was motivated by an earlier study that had shown a reduced risk for dry eye in caffeine users: 13 percent of users had the syndrome compared with nearly 17 percent of non-users. The team knew that caffeine was likely to stimulate tear glands, since it is known to increase other secretions, such as saliva and digestive juices. They also knew that people respond differently to caffeine, so they analyzed study participants' DNA samples for two genetic variations that play important roles in caffeine metabolism. Tear production proved to be higher in study subjects who had the two genetic variations.

"If confirmed by other studies, our findings on caffeine should be useful in treating dry eye syndrome," said Dr. Arita. "At this point, though, we would advise using it selectively for patients who are most sensitive to caffeine's stimulating effects."

The study subjects were divided into two groups: one received caffeine tablets in the first session and a placebo in the second session, while the order was reversed for the other group. Tear volume was measured within 45 minutes of consuming the tablets. All sessions took place between 10 a.m. and noon, a time of day when tear production is usually stable. No subjects knew whether they received caffeine or the placebo. All abstained from caffeine use for six days prior to each session and used no drugs during the sessions. To be eligible for the study subjects had to be free of high blood pressure, dry eye syndrome, allergies that affect the eye, glaucoma, and other eye diseases and conditions that can interfere with tear production. The study also found that tear drainage rates were not affected by caffeine.

Dry eye can be very uncomfortable and interfere with vision. It's important to see an ophthalmologist if symptoms continue, since advanced cases can cause eye damage and permanent vision problems. Current treatment options range from simple warm compresses, eye washes and artificial tears to medications and tear drainage devices.

-end-

Note to media: Contact Media Relations to request full text of the study, arrange interviews with experts, and request images.

About the American Academy of Ophthalmology

The American Academy of Ophthalmology is the world's largest association of eye physicians and surgeons -- Eye M.D.s -- with more than 32,000 members worldwide. Eye health care is provided by the three "O's" - ophthalmologists, optometrists, and opticians. It is the ophthalmologist, or Eye M.D., who can treat it all: eye diseases, infections and injuries, and perform eye surgery. For more information, visit www.aao.org. The Academy's EyeSmart® public education program works to educate the public about the importance of eye health and to empower them to preserve their healthy vision, by providing the most trusted and medically accurate information about eye diseases, conditions and injuries. Visit www.geteyesmart.org to learn more.

American Academy of Ophthalmology
Systematic review confirms longstanding caffeine intake recommendations
A rigorous, new scientific Systematic Review paper on caffeine safety confirms the results of the widely-cited Health Canada literature review (2003), which concluded that adverse health effects were not associated with caffeine intake levels at ≤400 mg/day for adults (which is the equivalent of about 4 cups of coffee/day, and 90 percent of Americans typically consume less than this amount ), ≤300 mg/day for pregnant women and ≤2.5 mg/kg-day for children and adolescents.
Caffeine boosts enzyme that could protect against dementia, finds IU study
A study by Indiana University researchers has identified 24 compounds -- including caffeine -- with the potential to boost an enzyme in the brain shown to protect against dementia.
For women, caffeine could be ally in warding off dementia
Higher caffeine intake in women is associated with reduced odds of developing dementia or cognitive impairment, according to the results of a new study published in The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences.
For women, caffeine could be ally in warding off dementia
Higher caffeine intake in women is associated with reduced odds of developing dementia or cognitive impairment, according to the results of a new study published in The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences.
Light and caffeine improve driver alertness: CARRS-Q study
Bright light combined with caffeine can improve driving performance and alertness of chronically sleep deprived young drivers, according to a Queensland University of Technology road safety study.
Caffeine has little to no benefit after 3 nights of sleep restriction
A new study found that after restricting sleep to 5 hours per night, caffeine use no longer improved alertness or performance after three nights.
Increased education could help adolescents limit caffeine consumption
Caffeine is the most available and widely used psychoactive substance in the world and is the only drug legally accessible and socially acceptable for consumption by children and adolescents.
Moderate amounts of caffeine during pregnancy do not harm baby's IQ
Women drinking and eating moderate amounts of caffeine during pregnancy should be reassured that they are not harming their child's intelligence, according to a study from The Research Institute at Nationwide Children's Hospital that was published in the American Journal of Epidemiology.
Brief cognitive-behavioral therapy helps those with problematic caffeine use
Engaging in brief, cognitive-behavioral therapy is an effective treatment for helping people with problematic caffeine use lower their caffeine consumption, according to a new study coauthored by Laura M.
How to stay awake without caffeine
You're tired and you need an energy boost, but you don't want the jitters from caffeine.

Best Science Podcasts 2017

We have hand picked the best science podcasts for 2017. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.

Now Playing: Radiolab

Truth Trolls
Today, a third story of folks relentlessly searching for the truth. But this time, the truth seekers are an unlikely bunch... internet trolls.


Now Playing: TED Radio Hour

Rethinking School
For most of modern history, humans have placed smaller humans in institutions called schools. But what parts of this model still work? And what must change? This hour, TED speakers rethink education.TED speakers include teacher Tyler DeWitt, social entrepreneur Sal Khan, international education expert Andreas Schleicher, and educator Linda Cliatt-Wayman.