Consuming large amounts of caffeine increases the risk of glaucoma by more than three times for people who are genetically predisposed to high eye pressure (IOP). Researchers at Mount Sinai Medical Center’s Icahn School of Medicine have uncovered the dangers of coffee to vision.
The experts analyzed records of more than 120,000 participants collected between 2006 and 2010. The volunteers, who also provided samples of their DNA, ranged in age from 39 to 73. They filled out dietary questionnaires, noting how many caffeinated drinks they drank daily, as well as which caffeine-containing foods they consumed and in what portions. The researchers took into account a family history of glaucoma.
After three years, participants had their intraocular pressure measured and their eyes examined. Overall, high caffeine consumption was not associated with an increased risk of higher IOP or glaucoma. However, a quarter of the volunteers who were found to have the highest genetic predisposition to glaucoma, a love of coffee and caffeine-containing products was associated with a high risk of developing IOP and glaucoma.
Specifically, consumption of more than 480 milligrams of coffee per day (approximately equivalent to four cups of coffee) contributed to an eye pressure of 0.35 millimeters of mercury. At high genetic risk, consumption of approximately three cups of coffee per day increased the risk of glaucoma by 3.9 times compared to those who consumed minimal or no caffeine.
In glaucoma, intraocular pressure is higher than normal, leading to irreversible visual defects, including decreased visual acuity, reduced visual field, and optic atrophy. Treatment can slow the progression of the disease, which leads to blindness.