Medscape Medical News
Veronica Hackethal, MD
June 11, 2014
Using a computer for long hours is linked to dry eye disease and decreased concentrations of Mucin5AC (MUC5AC) in tears, according to a study conducted among Japanese office workers and published online June 5 in JAMA Ophthalmology.
This is the first study to link MUC5AC, which belongs to a group of protective substances in tears called mucins, with dry eye disease and computer use. Dry eye disease has been associated with impairment in performing daily activities, as well as decreased productivity at work. Past studies have linked frequent computer use to dry eye disease and suggested an association between the dry eye symptoms of Sjögren’s syndrome and decreased concentrations of MUC5AC.
“Our data mean that secreted mucin (MUC5AC), which is a lubricant in human tears, is decreased in people using computers. Furthermore, our data show that the eye strain group had significantly lower concentrations of MUC5AC in tears,” first author Yuichi Uchino, MD, PhD, an assistant professor at Keio University School of Medicine in Tokyo, Japan, told Medscape Medical News.
“When ophthalmologists see dry eye patients with substantial eye strain, they should assess whether MUC5AC concentrations are decreased in tears in these patients,” Dr. Uchino advised, mentioning 2 medications that induce MUC5AC secretion from goblet cells in the conjunctiva: diquafosol tetrasodium (3% Diquas ophthalmic solution, Santen Pharmaceuticals), available in Japan and South Korea, and rebamipide (Mucosta ophthalmic suspension UD2%, Otsuka Pharmaceutical), available in Japan only.
Called the Osaka Study, the current study included 96 volunteers (60 men, 36 women) employed as Japanese office workers, who completed questionnaires about their dry eye symptoms and daily computer use, which they categorized as short (<5 hours), intermediate (5 – 7 hours), and long (>7 hours). Researchers conducted clinical exams and diagnosed dry eye disease as definitely present, probable, or not present. They also analyzed tear fluid from both eyes for concentration of MUC5AC.
Participants had a mean age of 41.7 years and a median duration of computer use of 8.2 hours per day. Nine percent (n = 9) had definite dry eye disease, whereas 57% (n = 55) had probable dry eye disease. Computer users with definite dry eye disease had lower mean MUC5AC concentrations compared with those without dry eye disease (3.5 ng/mg vs 8.2 ng/mg, respectively; P = .02).
Likewise, those with longer computer use had lower mean MUC5AC concentrations than those with shorter computer use (>7 hours: 5.9 ng/mg vs <5 hours: 9.6 ng/mg, respectively; P = .049). Those with symptomatic eye strain also had lower mean MU5AC concentrations compared with those without symptoms of eye strain (5.1 ng/mg vs 8.2; P = .001).
The authors note, however, that the definite dry eye disease group (n = 9) was much smaller than the probable dry eye disease (n = 55) and no dry eye disease (n = 32) groups, which could have introduced sample bias into the results.
“The link between computer use and dry eye disease is probably not coincidental, since people who use these devices blink at a rate that is one-third less than normal, and we know that blinking and lubricating of the surface is important to prevent dryness,” Mina Massaro-Giordano, MD, associate professor of clinical ophthalmology at the University of Pennsylvania School of Medicine and codirector of the Penn Dry Eye and Ocular Surface Center, Philadelphia, told Medscape Medical News when contacted for an outside opinion. “Patients who use these devices have more symptoms, and if they have an underlying surface disease issue, it can be exacerbated with computer use.”
Dr. Massaro-Giordano mentioned, however, that a decrease in MUC5AC may be only 1 reason why people who use computers develop dry eye symptoms. The tear film is made of a complex mix of fluid, mucous, and oil. MUC5AC is considered a gel-forming mucin, and Dr. Massaro-Giordano explained that alterations in other types of secretory mucins, such as soluble, surface, or transmembrane mucins, may also be linked to dry eye symptoms. Other causes of surface dryness could include tear insufficiency, evaporative dry eye problems, changes in the amount of oil released from glands in the lids, decreased blink rate, contact lens wear, hormones, environmental causes, and medications.
“When computer use is part of the problem, ophthalmologists should address and treat the problems of dry eye,” Dr. Massaro-Giordano urged, “Ophthalmologists should do a refraction test to make sure the patient is wearing the appropriate prescription and the right type of glasses and [should] discuss the ergonomics of computer use, including screen height, chair position, and glare protection.”
This study was sponsored by a Grant-in-Aid for Young Scientists from the Ministry of Health, Labour and Welfare and the Ministry of Education, Science, Sports, and Culture, and Santen Pharmaceutical Co, Ltd. Two coauthors report being consultants to and 2 coauthors are employees of Santen Pharmaceutical Co, Ltd. The other authors and Dr. Massaro-Giordano have disclosed no relevant financial relationships.
JAMA Opthalmol. Published online June 5, 2014. Abstract
Another Story from Yahoo
Staring at screens all day linked to changes in eye secretions
Reuters
By By Kathryn Doyle
NEW YORK (Reuters Health) – Office workers who spend long hours looking at computer screens have changes in their tear fluid similar to people with the disease known as dry eye, according to a study from Japan.
The protein MUC5AC, secreted by cells in the upper eyelid, makes up part of the normally occurring mucus layer, or “tear film,” that keeps the eye moist. But study participants with the most screen time had MUC5AC levels nearing those of people with diagnosed dry eye.
“To understand patients’ eye strain, which is one of major symptoms of dry eye disease, it is important that ophthalmologist pay attention to MUC5AC concentration in tears,” said Dr. Yuichi Uchino, an author of the new study.
Uchino is an ophthalmologist at the School of Medicine at Keio University in Tokyo.
“When we stare at computers, our blinking times decreased compared to reading a book at the table,” he told Reuters Health by email.
People staring at screens also tend to open their eyelids wider than while doing other tasks, and the extra exposed surface area in addition to infrequent blinking can accelerate tear evaporation and is associated with dry eye disease, he said.
Dry eye may be chronic for some but can be managed with over the counter or prescription eye drops.
Past research suggests that up to 5 million men and women over age 50 in the United States suffer from dry eye disease, the researchers write in their report. In Japan, tens of millions of people report some dry eye symptoms, often associated with computer work, they add.
The study team tested the tears from both eyes of 96 Japanese office workers, about two-thirds of them men, and measured how much of the total protein content of the tears was MUC5AC.
Workers employed in jobs involving computer screens filled out questionnaires about their working hours and symptoms of any eye problems.
Seven percent of men and 14 percent of women were diagnosed with ‘dry eye disease,’ meaning they reported symptoms of eye problems like irritation, burning or blurred vision and had poor quality or quantity of tear film, according to the tests.
Overall, participants looked at screens for work for just over eight hours a day and had an average of about 6.8 nanograms of MUC5AC per milligram of protein in each eye.
However, people who worked with computer screens for more than seven hours per day had an average of 5.9 ng/mg of MUC5AC, compared to 9.6 ng/mg for people who spent fewer than five hours daily with screens.
Similarly, people with definite dry eye disease had an average of 3.5 ng/mg of MUC5AC compared to 8.2 ng/mg for people without the disease.
“Mucin is one of the most important components of the tear film,” said Dr. Yuichi Hori, who was not a part of the new study. “Mucins (like MUC5AC) function to hold water on the ocular surface of the epithelia that synthesize them, hence, they are major players in maintenance of the tear film on the ocular surface,” Hori told Reuters Health by email.
He is chair of the department of Ophthalmology at Toho University Omori Medical Center in Tokyo.
Concentration of the protein was also lower for people with symptoms of eye strain than for people without symptoms, according to the results published in JAMA Ophthalmology.
People with dry eyes at work tend to be less productive and are more likely to be depressed, according to previous studies, Uchino said.
Office workers who are worried about dry eye can make some simple changes to decrease their risk, Uchino said.
“The exposed ocular surface area can be decreased by placing the terminal at a lower height, with the screen tilted upward,” Uchino said.
Doctors also recommend using a humidifier at the office and avoiding being in the direct path of the wind from an air conditioner, he said.
“We advise the office workers suffering from ocular fatigue and dry eye symptoms that they should blink more frequently in an intended manner during (screen use), and that they should use artificial tears,” Hori said.
“And they should ask an eye care doctor if their symptoms still remain.”
SOURCE: http://bit.ly/1oTQ4ov JAMA Ophthalmology, June 5, 2014.