Habitual coffee consumption may lower IOP but not risk of developing glaucoma

Habitual coffee consumption lowers Intraocular Pressure in normal individuals. However it may not lower risk of developing glaucoma, finds a Japanese study. 

The Nagahma study has been published in the Ophthalmology Glaucoma on November 5, 2020. 

Caffeine acts as a central nervous system stimulant. Studies have found that people who drink coffee regularly have a lower risk of developing Alzheimer's and dementia, and cut suicide risk by 45%. But its effect on Intraocular pressure remains unknown. For this purpose, a research team conducted a prospective, cross-sectional cohort study to evaluate the association between daily coffee consumption and intraocular pressure (IOP) in healthy subjects without glaucoma and the association between daily coffee consumption and history of glaucoma.

The study included 9,850 individuals in the first follow-up of the Nagahama Prospective Cohort for Comprehensive Human Bioscience (the Nagahama study) conducted between 2013 to 2016. All subjects underwent a standardized ophthalmic examination and were evaluated by self-reporting questionnaires.

Researchers analyzed the association between habitual coffee consumption and intraocular pressure (IOP) among non-glaucoma individuals using multivariable linear regression analysis. They also evaluated the association between habitual coffee consumption and history of glaucoma using multivariable logistic regression analysis.

Among 9,850 participants, 9,418 subjects had no history of Glaucoma, and their average IOP on both eyes was 14.7 ± 2.9 mmHg. Using multivariable regression analysis, researchers found frequent coffee consumption lowers the IOP. The IOP of the individuals who consumed coffee more often was 0.4 mmHg which is comparatively less than the individuals who consumed coffee least frequently (less than once a day).  

Researchers using the logistic regression analysis, also found that habitual coffee consumption was not significantly associated with the history of glaucoma. 

The authors concluded, "Frequent coffee consumption was associated with a slightly lower IOP in people without glaucoma, but was not associated with a decreased risk of developing glaucoma."

"Additional experimental studies are needed to examine the effects of coffee on IOP and glaucoma risk." the authors further added. For further information:

DOI:https://doi.org/10.1016/j.ogla.2020.09.019