The acute effect of pilocarpine on pulsatile ocular blood flow in ocular hypertension.
PURPOSE: To determine the acute effects of application of 2% pilocarpine on pulsatile ocular blood flow. METHODS: In a randomised prospective controlled study of an exploratory nature, 18 subjects with ocular hypertension had pilocarpine 2% eye drops instilled into a randomly chosen eye three times at 10 min intervals. Physiological saline was instilled into the contralateral control eye. Intraocular pressure (IOP) and pulsatile ocular blood flow (POBF) measurements were taken before the first application and 90 min after the last application using the OBF tonometer (OBF Laboratory, Wilts, UK). Statistical analysis was performed using the Wilcoxon signed rank test. RESULTS: Of the 18 patients who entered the trial, 2 were suggested by the OBF system software as having 'poorly reliable' data. The analysis was made on the remaining 16. There was a significant reduction in IOP at 90 min for the treated eye in comparison with the contralateral control eye (p = 0.001; median difference -4.25 mmHg; 95% confidence interval, -5.85 to -2.40). There was a significant increase in POBF at 90 min in the treated eye in comparison with the contralateral control eye (p < 0.001; median difference 4.60 microl/s; 95% confidence interval, 2.35 to 6.75). CONCLUSION: Acute application of pilocarpine 2% drops increased POBF to a significant extent in untreated ocular hypertension.