Individuals with a mother or father or sibling recognized with glaucoma ought to contemplate 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 when you’re occupied with lowering your threat of the illness, it’s one thing I might undoubtedly entertain.”
Pascale and his colleagues reported their findings in Ophthalmology.
Glaucoma causes injury to the optic nerve, usually from elevated strain from a buildup of fluid inside the attention. It may well trigger blindness.
The illness is extra frequent in folks with shut relations who’ve it. And researchers have recognized variants in a number of genes which might be extra frequent in folks with glaucoma.
In earlier research, individuals who take massive doses of caffeine have had momentary will increase in eye strain. So researchers have puzzled whether or not getting caffeine over a protracted time frame may pose a threat.
To assist reply that query, Pasquale and his colleagues regarded on the information of greater than 100,000 folks. The information got here from the UK Biobank, a big survey performed in the UK. The information included info on sufferers’ genes, how a lot tea or espresso they drank, their eye strain, and whether or not they had glaucoma.
Taking a look at all of the contributors collectively, the researchers didn’t discover any elevated threat of glaucoma from caffeine. In actual fact, they discovered that individuals who obtained essentially the most caffeine really had barely decrease eye strain.
However after they regarded solely at folks whose genes had been related to glaucoma, they discovered that caffeine was linked to increased common eye strain and likewise to a better threat of glaucoma.
That was notably true after they regarded on the 25% of people that obtained greater than 321 milligrams of caffeine — the equal of three cups of espresso — a day. When these folks had been additionally within the high 25% of genetic threat for elevated eye strain, that they had a a lot increased threat of glaucoma. They had been nearly 4 instances extra more likely to have the illness than individuals who didn’t devour caffeine and had been on the lowest 25% genetic threat.
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 increased eye strain or glaucoma for espresso, just for tea. However that’s doubtless due to a statistical drawback, says research co-author Anthony Khawaja, affiliate professor on the College School 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 most likely not sufficient folks within the database who drink massive quantities of espresso to investigate their glaucoma threat.
Individuals in each the highest 25% for genetic threat and high 25% for tea consuming (3 to six cups of tea a day), had been nearly 3 times as more likely to have glaucoma in comparison with these within the lowest 25% for tea consuming and lowest 25% for genetic threat.
Nevertheless, this sort of research can not show that caffeine will increase the danger of glaucoma or excessive eye strain, even amongst folks with a genetic threat, Pasquale says. He and his colleagues wish to do a follow-up research by which they provide caffeine to teams of individuals with completely different genetic dangers, then examine the results on eye strain.
Sufferers mustn’t depend on altering their caffeine consumption as a method of treating their glaucoma, says Asaf Achiron, MD, an ophthalmologist on the Sackler School of Drugs in Tel Aviv, Israel, who has studied the connection of life-style and eye strain. Caffeine didn’t have a giant impact for most individuals within the research, 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 strain,” he says in an e-mail.
Nonetheless, the discovering could be value mentioning to sufferers, he says. “I do not focus on tea with my sufferers simply measure their [eye pressure]. Maybe I ought to.”