Researchers from Kyoto, Japan, have noted an association between frequent coffee consumption and lower IOP in patients without glaucoma. Habitual coffee consumption was not significantly associated with glaucoma.

In 9,418 study participants without glaucoma, the average IOP of both eyes was 14.7mm Hg. All participants underwent a standardized ophthalmic exam and then completed a self-reported questionnaire on coffee intake.

The researchers’ analysis revealed that habitual coffee consumption was significantly associated with reduced IOP. The IOP of the group that consumed coffee more frequently (three times a day or more) was 0.4mm Hg lower than that of the group that consumed coffee less frequently (less than once a day).

The researchers concluded that additional experimental studies would help examine the effects of coffee on IOP and glaucoma risk.

Nakano E, Miyake M, Hosada Y, et al. Relationship between intraocular pressure and coffee consumption in a Japanese population without glaucoma: the Nagahama study. Ophthalmology. November 5, 2020. [Epub ahead of print].