Individuals with a dad or mum or sibling identified with glaucoma ought to think about limiting caffeine to the quantity in two cups of coffee a day, says Louis Pasquale, MD, an ophthalmology professor at Mount Sinai Well being System in New York Metropolis.
“It’s a suggestion,” he says. “It’s not one thing set in stone, however if you happen to’re interested by decreasing your danger of the illness, it’s one thing I’d undoubtedly entertain.”
Pascale and his colleagues reported their findings in Ophthalmology.
Glaucoma causes injury to the optic nerve, usually from elevated stress from a buildup of fluid inside the attention. It could actually trigger blindness.
The illness is extra widespread in individuals with shut members of the family who’ve it. And researchers have recognized variants in a number of genes which might be extra widespread in individuals with glaucoma.
In earlier research, individuals who take giant doses of caffeine have had non permanent will increase in eye stress. So researchers have puzzled whether or not getting caffeine over an extended time frame may pose a danger.
To assist reply that query, Pasquale and his colleagues seemed on the data of greater than 100,000 individuals. The data got here from the UK Biobank, a big survey carried out in the UK. The data included data on sufferers’ genes, how a lot tea or espresso they drank, their eye stress, and whether or not they had glaucoma.
Taking a look at all of the members collectively, the researchers didn’t discover any elevated danger of glaucoma from caffeine. The truth is, they discovered that individuals who acquired essentially the most caffeine really had barely decrease eye stress.
However after they seemed solely at individuals whose genes had been related to glaucoma, they discovered that caffeine was linked to greater common eye stress and likewise to a better danger of glaucoma.
That was significantly true after they seemed on the 25% of people that acquired greater than 321 milligrams of caffeine — the equal of three cups of espresso — a day. When these individuals had been additionally within the high 25% of genetic danger for elevated eye stress, they’d a a lot greater danger of glaucoma. They had been nearly 4 occasions extra prone to have the illness than individuals who didn’t eat caffeine and had been on the lowest 25% genetic danger.
The researchers discovered that the mixture of caffeine and genes elevated the danger of glaucoma greater than the genes alone.
The researchers couldn’t discover a statistical hyperlink to greater eye stress or glaucoma for espresso, just for tea. However that’s seemingly due to a statistical drawback, says examine co-author Anthony Khawaja, affiliate professor on the College Faculty London Institute of Ophthalmology. “The reply is kind of easy− the UK is a tea consuming nation!” he says in an e mail. There have been in all probability not sufficient individuals within the database who drink giant quantities of espresso to research their glaucoma danger.
Individuals in each the highest 25% for genetic danger and high 25% for tea consuming (3 to six cups of tea a day), had been nearly thrice as prone to have glaucoma in comparison with these within the lowest 25% for tea consuming and lowest 25% for genetic danger.
Nevertheless, such a examine can not show that caffeine will increase the danger of glaucoma or excessive eye stress, even amongst individuals with a genetic danger, Pasquale says. He and his colleagues want to do a follow-up examine by which they provide caffeine to teams of individuals with completely different genetic dangers, then examine the results on eye stress.
Sufferers shouldn’t depend on altering their caffeine consumption as a manner of treating their glaucoma, says Asaf Achiron, MD, an ophthalmologist on the Sackler College of Drugs in Tel Aviv, Israel, who has studied the connection of way of life and eye stress. Caffeine didn’t have a giant impact for most individuals within the examine, he factors out.
“Glaucoma is a fancy illness. In some circumstances it continues to progress even when [eye pressure] is lowered by the drops so clearly there are extra points right here than stress,” he says in an e mail.
Nonetheless, the discovering may be price mentioning to sufferers, he says. “I do not talk about tea with my sufferers simply measure their [eye pressure]. Maybe I ought to.”