Exploring the causal link between long-term elevated plasma caffeine levels and age-related eye diseases using Mendelian randomization

This study provides novel evidence on the long-term effects of caffeine on age-related eye diseases, including age-related macular degeneration (AMD), age-related cataract (ARC), and primary open-angle glaucoma (POAG). Unlike previous studies that used imprecise measures of caffeine exposure, such as caffeinated beverage intake, we utilized fasting plasma caffeine levels, offering a more accurate assessment of individual exposure. Through Mendelian randomization, we demonstrate that long-term caffeine exposure is independently associated with reduced risks of AMD and ARC, and is also linked to a lower risk of POAG, with approximately half of this effect mediated through intraocular pressure (IOP) reduction. Our findings suggest that caffeine could play a protective role in ocular health, offering new insights into potential prevention strategies for age-related eye diseases.