[1,3,7-trimethylxanthine. Effects on circadian aqueous humor dynamics in probands]

Anterior chamber fluorophotometry (Fluorotron Master II, Coherent, Palo Alto, Calif.) was used to investigate the influence of 1,3,7-trimethylxanthin on the circadian rhythm of aqueous humor secretion in two age-, race- and sex-matched groups of healthy volunteers. In ten males and ten females (mean age 27 years), aqueous humor secretion was measured over 24 h at: 0800, 0900, 1000-1400, 1500, 1600-2000, 2100, 2200-0200, 0300, and 0400 hours. Flow was calculated using the Yablonsky protocol of Fluorotron Master II. In group I all volunteers received about 800 mg trimethylxanthin in the form of caffeinated coffee between 2200 and 2300 hours. In group II volunteers went to sleep at 2300 hours. Sleep was only interrupted for measurements. During the daytime the mean aqueous humor flow was the same in both groups (0800 to 2200 hours) (Student's t-test): Group I (n = 10) RA 2.27 +/- 0.70 microliters/min LA 2.25 +/- 0.74 microliters/min Group II (n = 10) RA 2.23 +/- 0.73 microliters/min LA 2.06 +/- 0.64 microliters/min During the night the mean aqueous humor flow decreased in both groups (0200 to 0400 hours): Group I: RA 1.99 +/- 0.74 microliters/min delta flow = -12% LA 1.93 +/- 0.75 microliters/min Group II: RA 0.97 +/- 0.50 microliters/min delta flow = -56% LA 0.97 +/- 0.48 microliters/min The difference between groups was statistically significant (P = 0.01, t-test for unpaired samples). There was no significant change in mean aqueous humor flow between the daytime vs night in group I (P < 0.5).(ABSTRACT TRUNCATED AT 250 WORDS)