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Aqueous Humor Dynamics and Brimonidine (Brimonidine)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01144494
Recruitment Status : Completed
First Posted : June 15, 2010
Results First Posted : April 24, 2019
Last Update Posted : May 22, 2019
Information provided by (Responsible Party):
Carol B. Toris, BA MS PhD, University of Nebraska

Brief Summary:
Investigate nocturnal effects on aqueous humor dynamics of a clinically used eye pressure -lowering drug, brimonidine, when given for six weeks.

Condition or disease Intervention/treatment Phase
Intraocular Pressure Drug: Brimonidine Drug: Artificial tears Not Applicable

Detailed Description:

This single-center, investigator-masked, crossover study is designed to investigate the circadian rhythms of aqueous humor dynamics in human subjects with ocular hypertension (OHT) before and after intervention with a commonly used ocular hypotensive medication, brimonidine. Thirty volunteers with ocular hypertension (intraocular pressure greater than 20mmHg) will be enrolled.

The subjects will undergo a baseline phase and medication phase using brimonidine. At both phases, they will attend a daytime and a nighttime study visit in which fluorophotometry will be used to calculate aqueous flow (production), trabecular outflow facility, and uveoscleral outflow. At the completion of the study, subjects will return to their previous ophthalmic clinic.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 35 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: Circadian Rhythms of Aqueous Humor Dynamics in Subjects With Ocular Hypertension Using Brimonidine
Actual Study Start Date : June 2010
Actual Primary Completion Date : January 2011
Actual Study Completion Date : January 2012

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: Intraocular pressure lowering drug
Eyedrops for lowering intraocular pressure
Drug: Brimonidine
One drop of brimonidine in each eye three times a day for six weeks.

Placebo Comparator: Artificial Tears
Lubricated eye drops
Drug: Artificial tears
Lubricating drops added three times a day for six weeks
Other Name: Systane

Primary Outcome Measures :
  1. Seated Day-time IOP 9 am and 11 am, Supine Day-time IOP 9 am and 11 am, and Seated Night-time IOP 9 pm and 11 pm [ Time Frame: 6 weeks ]
    Seated day-time and supine day-time IOP was measured by pneumatonometer at 9 am and 11 am. Seated night-time IOP was measured at 9 pm and 11 pm.

  2. Supine Night-time & Day-time Seated Episcleral Venous Pressure (EVP) [ Time Frame: 6 weeks plus 2 days ]
    The episcleral venous pressure was measured using the episcleral venomanometer

Secondary Outcome Measures :
  1. Aqueous Flow [ Time Frame: 6 weeks ]
    Measured by fluorophotometry during the day and night on 29 participants.

  2. Uveoscleral Outflow [ Time Frame: 6 weeks ]
    Calculated from the modified Goldmann equation using data obtained at 9 am and 11 am. Goldmann equation involves data from aqueous flow, tonography/outflow facility, episcleral venous pressure and IOP. Tonography/outflow facility data on 2 participants were not reliable, therefore uveosleral outflow analysis was performed on 27 participants.

  3. Outflow Facility [ Time Frame: 6 weeks ]
    Calculated from the measurement taken during the day and night. Tonography/outflow facility data was not reliable in 2 of the participants, therefore analysis was conducted on data from 27 participants.

Information from the National Library of Medicine

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Ages Eligible for Study:   19 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Subjects must be 19 years of age or older
  • Subjects must exhibit a history of untreated IOPs between 21 and 35 mmHg (inclusive)

Exclusion Criteria:

  • Age less than nineteen years old
  • Women who are pregnant, lactating or of childbearing potential who are not using birth control measures.
  • Aphakia or pseudophakia
  • Best corrected visual acuity worse than 20/60 in either eye
  • Chronic or recurrent severe ocular inflammatory disease
  • Ocular infection or inflammation within (3) months of screening visit.
  • History of clinically significant or progressive retinal disease such as retinal degeneration, diabetic retinopathy or retinal detachment.
  • Any abnormality preventing reliable tonometry of either eye.
  • Previous exposure to: beta-adrenergic antagonists, topical prostaglandin analogues within six (6) weeks of the baseline visit; α-adrenergic agonists within two (2) weeks of the baseline visit; and cholinergic agonists and carbonic anhydrase inhibitors within five (5) days of the treatment initiation visit.
  • History of any severe ocular pathology (including severe dry eye) that would prelude the administration of a topical beta blocker, carbonic anhydrase inhibitor, or a topical prostaglandin.
  • Any eye with a cup-to-disc ratio greater than 0.8.
  • History of intraocular surgery
  • History of ocular laser surgery
  • History of severe or serious hypersensitivity to brimonidine or its vehicle.
  • History of severe, unstable, or uncontrolled cardiovascular, hepatic or renal disease.
  • History of bronchial asthma or chronic obstructive pulmonary disease (COPD).
  • Less than one month (prior to baseline) stable dosing regimen of any non-glaucoma medication that would affect IOP.
  • Gonioscopy angle < 2.
  • Inability to be dosed with treatment medication
  • Inability to discontinue contact lens wear.
  • Therapy with any investigational agent within 30 days of screening.
  • Use of any additional topical or systemic adjunctive ocular hypotensive medications during the study.
  • History of open angle glaucoma (either primary open angle glaucoma or other cause of open angle glaucoma) or narrow angle glaucoma.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01144494

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United States, Nebraska
University of Nebraska Medical Center
Omaha, Nebraska, United States, 68198-5540
Sponsors and Collaborators
University of Nebraska
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Principal Investigator: Carol B Toris, PhD Research Instructor
Publications of Results:
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Responsible Party: Carol B. Toris, BA MS PhD, Principal Investigator, University of Nebraska Identifier: NCT01144494    
Other Study ID Numbers: 220-10-FB
First Posted: June 15, 2010    Key Record Dates
Results First Posted: April 24, 2019
Last Update Posted: May 22, 2019
Last Verified: May 2019
Keywords provided by Carol B. Toris, BA MS PhD, University of Nebraska:
Aqueous Humor Dynamics
Aqueous Humor Dynamics and Circadian Rhythms
Additional relevant MeSH terms:
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Brimonidine Tartrate
Lubricant Eye Drops
Antihypertensive Agents
Adrenergic alpha-2 Receptor Agonists
Adrenergic alpha-Agonists
Adrenergic Agonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs
Ophthalmic Solutions
Pharmaceutical Solutions