Effects of unoprostone on diurnal variation of intraocular pressure in healthy volunteers

PURPOSE: To prospectively evaluate the diurnal variation of intraocular pressure (IOP) during unoprostone treatment in 13 healthy volunteers. METHOD: IOP was measured by Goldmann applanation tonometry by the same observer every 3 hours from 9 am to 9 am the next morning. Unoprostone was then instilled at 9 am and 9 pm daily for 1 month. After 1 month, IOP was measured again with unoprostone instilled at 9 am and 9 pm during IOP measurement. We then compared the average daily IOP before and after the treatment (paired t-test). RESULTS: After 1 month of treatment, the average IOP decreased at every time point but one (12 pm, 3 pm, 6 pm, 9 pm, 12 am, 3 am, and 9 am, but not at 6 am). There were no adverse reactions and none of the subjects discontinued unoprostone. CONCLUSION: The hypotensive effects of unoprostone persist throughout the day, but this study suggests that the effects may be weaker at nighttime and early in the morning.