Caffeine and intraocular pressure in a Nigerian population

Purpose: Caffeine is widely consumed as kola nuts and in other products in sub-Saharan Africa. We examined the acute effect of caffeine on the intraocular pressures of healthy Nigerian volunteers between the ages of 20 and 27 years. Methods: Intraocular pressure and blood pressure were measured 0, 30, 60, and 90 minutes after the ingestion of coffee by two groups of participants, namely the experimental (caffeinated coffee) and control (decaffeinated coffee) groups. Results: The result showed that ingested caffeine increases intraocular pressure and that the elevation, though variable across patients, is sustained for several minutes. The mean increase across patients rises monotonically with the postingestion time and by almost 4 mm Hg. There was also a corresponding increase in systolic and diastolic blood pressure of the caffeinated group. There was relatively no change in intraocular pressure or blood pressure with time in the control group. The difference between both groups was statistically significant (P < 0.05). Conclusions: The results suggest the need for more glaucoma screenings and proper patient education, particularly in Nigerian populations in which the consumption of caffeine, contained in kola nuts and in other raw and processed products, is endemic and long-term.