ISLAMABAD - Hours in front of a computer screen may increase the risk of glaucoma in people who are myopic or short-sighted, Japanese scientists said. Glaucoma, which is caused by damage to the optic nerve, results in blind spots or visual impairments that can rob people of their sight.  Smoking and high blood pressure are potential risk factors but Japanese researchers believe excessive computer use may also play a role in short-sighted people.

“Myopic workers with a history of long-term computer using might have an increased risk of visual field abnormalities, possibly related to glaucoma,” Dr Masayuki Tatemichi, of the Toho University School of Medicine in Tokyo, said in a report in the British Journal of Ophthalmology.  The researchers studied about 10,000 workers in Japan who were chosen for testing as part of a routine medical check-up. They also completed a questionnaire about how much time they spent using a computer and any eye problems. The average age of the participants was 43.

About 5 percent of the workers in the study had visual field problems. A further test revealed about a third of them had suspected glaucoma. The scientists said there appeared to be a link between glaucoma and heavy computer use in the short-sighted.

They believe the optic nerve in short-sighted people may be more vulnerable to computer stress than in normal eyes.

“Computer stress is reaching higher levels than have ever been experienced before. In the next decade, therefore, it might be important for public health professionals to show more concern about myopia and visual field abnormalities in heavy computer users,” the scientists added.

Brain inflammation found in autism: Children with autism have inflammation in their brains, although it is not yet clear whether the inflammation actually causes the condition, researchers said. Tests on the brain tissue of 11 patients with autism who had died and spinal fluid from six living children with autism showed the activation of immune system responses, the team at Johns Hopkins University School of Medicine in Baltimore and the University of Milan found.

“These findings reinforce the theory that immune activation in the brain is involved in autism, although it is not yet clear whether it is destructive or beneficial, or both, to the developing brain,” said Dr. Carlos Pardo-Villamizar of Johns Hopkins, who led the study. Autism is a brain disorder usually seen as children become toddlers. Affecting an estimated two to five out of every 1,000 children, autism has a spectrum of symptoms that include difficulty with social interaction and repetitive behaviors.

In a study published in the online edition of the Annals of Neurology, Pardo and colleagues said they found abnormal activity by immune system signaling chemicals called chemokines in the autistic patients. “This ongoing inflammatory process was present in different areas of the brain and produced by cells known as microglia and astroglia,” said Pardo.

“Scientists have found hints that the immune system may be involved in autism, but not all studies have confirmed this,” Pardo added in a statement.

“We wanted a more definitive answer, so rather than looking at the overall immune system, we focused on immune responses inside the relatively sealed environment of the nervous system.”

No one knows what causes autism, although experts have largely rejected purported links with childhood vaccines.

The condition is strongly influenced by genes. If one identical twin has autism, for instance, the other is also usually affected.

Pardo said more study would be needed to show if the inflammation itself underlies autism, or is a reaction to something else that causes the condition.