The Effect of Graded Doses of Caffeine on Intraocular Pressure in Niger Delta, Nigeria

Aim: To determine the effect of graded doses of caffeine on intraocular pressure in a Nigerian population.

Methods: This was a prospective, observer‐masked, cross‐over study carried out in the Eye clinic of the Ahoada General Hospital.

A total One hundred subjects comprising 46 males and 54females aged 20 – 76 years were chosen. Graded doses of caffeine were administered to the subjects in four groups. The fourth group was the control and subjects here were given water only without caffeine.

Intra Ocular Pressure of each subject was determined at different times after oral ingestion of coffee.

Data was analysed using SPSS program for windows (statistical package for the social sciences Inc., version 16).

Results: The group which consumed 3.5 mg/kg body weight of caffeine had the maximum mean increase in IOP (5.20±0.08 mmHg) after 60 minutes, the pressure remained the same after 90 minutes and then reduced to 4.28±0.13mmHg after the 120 minutes while Group A which consumed 0.7mg/kg body weight of caffeine had the minimum mean increase in intraocular pressure (2.32± 0.82 mmHg) after 60 minutes, 2.2± 0.65mmHg after 90 minutes and then reduced to 1.4± 0.81 mmHg after the 120 minutes (p<0.005).

Maximum effect was observed after 60 minutes of ingesting caffeine and gradually returned to baseline values after 120 minutes. There was no significant change in IOP of subjects who ingested only water.

Conclusion: This study revealed a significant rise in intraocular pressure in normotensive human eyes and this increase was dose-dependent. Moderation in caffeine consumption remains very vital and calls for more public awareness platforms. Therefore we recommend that caffeine be consumed with caution especially in patients with glaucoma. Future studies relating to caffeine’s effects via inhalation and monitoring of caffeine’s effect on IOP beyond 120minutes is equally important.