People who drink a lot of coffee don’t appear to have a greater chance of developing glaucoma, although caffeine consumption may pose a greater risk in those with a stronger genetic predisposition of higher IOP, new research suggests.

The cross-sectional study included 121,374 participants between the ages of 39 and 73 with a mean IOP of 16mm Hg. This is the largest study to evaluate the association between habitual caffeine consumption and IOP and the first to explore whether this relationship is modified by genetic predisposition of higher IOP. 

Some of the key findings included:

Analysis didn’t support a causal effect between coffee drinking and IOP.

Greater caffeine intake was weakly associated with lower IOP: higher (more than 232mg/day) vs. lower (less than 87mg/day) caffeine consumption was associated with a 0.10mm Hg lower IOP. However, the IOP polygenic risk score significantly modified this association. Among those in the highest IOP genetic risk quartile, consuming more than 480mg/day vs. less than 80mg/day was tied to a higher IOP by 0.35mm Hg.

There was no relationship between caffeine intake and glaucoma development. Again, the polygenic risk score significantly modified this finding. Compared with those in the lowest IOP risk group who didn’t drink caffeine, those in the highest risk group who drank 321mg of caffeine or more each day were four times more likely to have glaucoma.

These findings are consistent with studies that found greater caffeine intake is more strongly associated with open-angle glaucoma in patients reporting a family history of glaucoma.

“If confirmed, our data suggest that approaches to precision nutrition that incorporate genomic data may be needed to make recommendations regarding caffeine consumption and glaucoma risk,” the researchers concluded in their paper.