The effect of dorzolamide on aqueous humor dynamics in normal human subjects during sleep1☆
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Received 29 August 1997; accepted 12 January 1998.
Abstract
Objective
The purpose of the study was to measure the effect of the topical carbonic anhydrase inhibitor, 2% dorzolamide hydrochloride, on the rate of aqueous humor flow in sleeping humans.
Design
A randomized, double-masked, placebo-controlled study.
Participants
Twenty-five normal human subjects.
Intervention
Topical instillation of 2% dorzolamide hydrochloride versus topical placebo.
Main outcome measures
Rate of aqueous humor flow in sleeping humans and intraocular pressure immediately after awakening from sleep.
Results
The rate of flow in sleeping subjects at night (12 am to 6 am) was 1.28 ± 0.30 μl/min (mean ± standard deviation; n = 25) in placebo-treated eyes, whereas the nighttime flow in dorzolamide-treated eyes was 1.17 ± 0.38 μl/min (P = <0.001), resulting in a nighttime reduction of 9% (P = 0.032). In contrast, the daytime (8 am to 4 pm) rate of flow in ambulatory subjects was 2.97 ± 0.64 μl/min in placebo-treated eyes and 2.60 ± 0.63 μl/min (P = 0.032) in dorzolamide-treated eyes, resulting in a daytime reduction of 13% (P = <0.001).
Conclusions
Topically administered dorzolamide hydrochloride is effective for reducing the rate of aqueous humor flow in normal human eyes during the day and at night during sleep. The efficacy of dorzolamide at these two times is approximately half that of systematically administered acetazolamide.
2Department of Ophthalmology, Mayo Clinic and Mayo Foundation, Rochester, Minnesota, USA
Reprint requests to Richard F. Brubaker, MD, Mayo Foundation, 200 First Street SW, Rochester, MN 55905 USA
☆ Supported in part by grant EY 00634 (Dr. Brubaker) from the National Institutes of Health, Bethesda, Maryland; an unrestricted grant from Research to Prevent Blindness, Inc., New York, New York; Human Health Services grant M01-RR0585, General Clinical Research Centers, Division of Research Resources, National Institutes of Health; and the Mayo Foundation, Rochester, Minnesota.
1 The authors have no proprietary interest in the development or marketing of this or a competing drug.
ABSTRACT