A study by the Icahn School of Medicine at Mount Sinai in the US is the first to show how caffeine and a patient’s genetic disposition increases the risk of glaucoma.

The study, published in Ophthalmology, evaluated the medical records and questionnaires of 120,000 participants aged 39 to 73 years, whose intraocular pressures (IOPs) and DNA samples were also taken. Researchers found that the top 25% of the group with a strong genetic predisposition to elevated IOP and glaucoma who consumed large amounts of caffeine (321mg or three cups of coffee) daily had a 3.9-fold higher glaucoma prevalence than minimal coffee drinkers with the lowest genetic risk. However, high caffeine intake was not associated with increased risk for higher IOP or glaucoma overall.

While previous studies have shown that caffeine effects a transient increase in IOP, evidence that it increases the risk of glaucoma for someone with a strong family history of the condition has been incomplete.

For more about coffee and glaucoma, see: https://eyeonoptics.co.nz/articles/archive/should-glaucoma-patients-avoid-caffeine/