Acute Effect of Caffeine on Amplitude of Accommodation and Near Point of Convergence
Caffeine is widely consumed in kola nuts and in other products in Sub-Saharan Africa. We examined the acute effect of caffeine on the amplitude of accommodation and near point of convergence of healthy Nigerians. Forty volunteers between ages of 20 and 27 years with refractive power± 0.50 DS were employed. Amplitude of accommodation (AMP) and Near point of convergence (NPC) were measured at 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. The result showed that ingested caffeine increases mean AMP by almost 2.00D within 30 minutes, and the elevation, though variable across patients is sustained for several minutes. The NPC and AMP in the decaffeinated coffee was statically insignificant (P>0.05) within the 0-90minutes of ingestion. However, there was a significant increase in the AMP of the experimental group (P< 0.05). The result suggests that further studies would be most desirable with the older and larger population.
Keywords: Caffeine, amplitude of accommodation, near point of convergence
West African Journal of Pharmacology and Drug Research Vol. 22/23 2007: pp. 27-30