AzTrials
AzTrials

GlaucomaNCT01105065

Effect of Alphagan on Retinal Blood Flow Autoregulation and Motion Detection in Patients With Normal Pressure Glaucoma

A study testing brimonidine 0.15% in people with Glaucoma, run by Massachusetts Eye and Ear Infirmary at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

The investigators have completed a study in which the investigators examined the response of the retinal circulation to changes in posture from sitting to lying down in patients with Normal Tension Glaucoma (NTG). Read more about this study

Who is it for?
Ages 35 to 80 years
Conditions the study is for
Glaucoma
What is being tested?
brimonidine 0.15%
Could I receive a placebo?
No, everyone receives an active treatment
How many people
46 participants
Where
1 siteUnited States
Study dates
Mar 2010to Sep 2012
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 35 to 80 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Eligible subjects will have no history of IOP > 24 mm Hg in either eye.
  • All subjects will have open angles on gonioscopy with the filtering portion of the trabecular meshwork visible for 360° in both eyes.
  • Previously or newly diagnosed patient are required to have HVFs that are reliable and show loss consistent with nerve fiber layer atrophy.
  • Patients with glaucoma-like discs (CDR>0.7 in either eye) and normal/reliable visual fields who the PI has opted to observe without treatment will enter the study if they meet the other study criteria.
  • In order to facilitate the retinal blood flow measurements, only subjects with refractive error within the range -10 to +10 diopters, no lens opacities greater than 1+ cortical spokes or 2+ nuclear sclerosis, and pupillary dilation of at least 6 mm following mydriasis will be included.

Who cannot join

  • Patients with evidence of exfoliation or pigment dispersion syndrome in either eye.
  • Patients with a cup/disc ratio > 0.8.
  • Known history of allergy to brimonidine.
  • Patients already on treatment with brimonidine will be excluded from the study.
  • Diabetic retinopathy.
  • History of ocular laser or incisional surgery in either eye.
  • Use of systemic alpha-2 blockers.
  • Pregnant or planning to become pregnant.

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Massachusetts Eye and Ear Infirmary

    Boston, Massachusetts, 02114

Other trials in United States

About this study

Official title: Effect of Brimonidine 0.15% on Retinal Blood Flow Autoregulation and Motion Detection in Patients With Normal Tension Glaucoma

The investigators have completed a study in which the investigators examined the response of the retinal circulation to changes in posture from sitting to lying down in patients with Normal Tension Glaucoma (NTG). This alteration in position produces changes in the local blood pressure at the entrance to the retinal vasculature. In a healthy retina, the vasculature adapts by dilating and constricting in order to maintain a steady blood flow rate. In an eye with NTG, this often does not occur. Upon analysis at the completion of the study , the investigators found that the patients who had been taking Alphagan (brimonidine) during the study did not exhibit the blood flow increases typical of NTG while lying down; instead, they maintained a steady blood flow rate as did the group of healthy control subjects. The investigators primary objective is to now demonstrate in a prospective study that Alphagan can restore retinal vascular autoregulatory function in patients with NTG who do not autoregulate. The investigators will also determine the effect of Alphagan treatment on the patients' ability to detect motion.

Read the detailed description

This is a prospective, nonrandomized clinical trial of POAG patients with a history of untreated IOP <22 mm Hg.

RETINAL VASCULAR AUTOREGULATION TESTING PROTOCOL:

At approximately 10 AM, we allowed subjects to sit for 15 minutes and then measured blood pressure and heart rate using a Keller Vital Signs Monitor (Keller Medical Specialties, Antioch, Illinois, USA). We measured seated IOP in both eyes using Goldmann applanation tonometry (Haag Streit USA, Mason, Ohio, USA) and 1 eye was dilated with tropicamide 1%. Baseline seated ocular perfusion pressure (OPP) was estimated using the standard formula: OPP=2/3 MAP - IOP, where MAP refers to mean arterial pressure. The factor of two-thirds adjusts for the decline in blood pressure between the brachial and ophthalmic artery with the subject sitting. We used the Canon CLBF 100 Laser Blood Flowmeter (Canon Inc, Tokyo, Japan) to measure baseline retinal arterial blood column diameter and centerline blood speed, which allows for automatic calculation of the blood flow rate. We chose a site along either the inferior temporal retinal artery or the superior temporal retinal artery adjacent to the optic disc for baseline measurements. Following the baseline measurements, the subjects assumed a posture typically used for face-on x-rays, reclining on their right side with their head supported by a foam wedge making a 24-degree angle from the horizontal. Subjects reclined for 30 minutes while brachial blood pressure and heart rate were automatically measured at 5-minute intervals. Laser Doppler blood flow measurements were obtained from the same arterial site that was used at baseline after approximately 15 and 30 minutes of reclining. Immediately following the 30-minute laser Doppler measurement, with the subject still reclining, we used the Perkins handheld applanation tonometry (Haag Streit USA) to remeasure IOP in the eye undergoing hemodynamic testing. In the reclined position, OPP was estimated using the following formula: OPPreclining = MAPreclining - IOPreclining, where MAPreclining is the mean brachial artery blood pressure measured in the left arm with the subject reclining on the right side. Subsequently, blood pressure, heart rate, and laser Doppler measurements were repeated after the subjects were reseated for 15 minutes.

Only patients who exhibited retinal vascular dysregulation continued in the study. We defined retinal vascular dysregulation based on the percentage change between the retinal blood flow measured while reclining for 30 minutes and the baseline seated measures. Previously, we found that healthy subjects exhibited a +6.5% +/- 12% blood flow change induced by 30 minutes of reclining. Thus, we defined the normal range of blood flow autoregulation as within 2 standard deviations of the mean percentage change found in this group, or -17.5% to +30.5%. Patients who exhibited retinal vascular dysregulation began an 8-week course of brimonidine 0.15% 3 times a day in both eyes. Subsequently, they returned at 10 AM and repeated the testing protocol described above. We obtained retinal hemodynamic measurements at the same retinal arterial site used during the initial visit. Each patient also underwent visual function testing in the eye that had hemodynamic studies both before and after 8-week treatment with brimonidine 0.15%.

Conditions
Glaucoma
Being tested
brimonidine 0.15%
Keywords
Normal Pressure Glaucoma
Medical subject headings
Glaucoma, Low Tension Glaucoma

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • brimonidine 0.15%Drug

    Also called Alphagan

    One drop in each eye three times a day for 8 weeks.

Study groups in NCT01105065
Study groupRoleWhat they receive
Patients with RVDExperimentalPatients who exhibited retinal vascular dysregulation at the initial visit. Intervention: brimonidine 0.15% three times per day for 8 weeks.
Receives: Drug: brimonidine 0.15%

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Presence of Retinal Blood Flow Autoregulation

    We defined retinal vascular dysregulation based on the percentage change between the retinal blood flow measured while reclining for 30 minutes and the baseline seated measures. In a prior study, we found that healthy subjects exhibited a +6.5%±12% blood flow change induced by 30 minutes of reclining. Thus, we defined the normal range of blood flow autoregulation as within 2 standard deviations of the mean percentage change found in this group, or -17.5% to +30.5%.

    Measured: 8 weeks

Secondary outcomes (1)
  1. Frequency Doubling Perimetry

    Frequency doubling perimetry was measured pre- and post treatment with brimonidine for 8 weeks.We used the full-threshold N-30 protocol to determine the visual field mean deviation, pattern standard deviation, and test duration in the eye that had hemodynamic testing. The results that are reported below are the mean deviation values recorded as part of the frequency doubling perimetry as these are the most significant.

    Measured: 8 weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted16 Apr 2010 (estimated)
  2. Study startMar 2010
  3. Primary completionSep 2012
  4. Study completionSep 2012

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
46 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01105065
Sponsor's protocol ID
10-03-019 (75643)
Status last verified
Mar 2017
First submitted
14 Apr 2010
Last updated
4 Apr 2017
Data monitoring committee
No
Individual data sharing
No

Publications

  • Feke GT, Bex PJ, Taylor CP, Rhee DJ, Turalba AV, Chen TC, Wand M, Pasquale LR. Effect of brimonidine on retinal vascular autoregulation and short-term visual function in normal tension glaucoma. Am J Ophthalmol. 2014 Jul;158(1):105-112.e1. doi: 10.1016/j.ajo.2014.03.015. Epub 2014 Apr 5.

    PubMed 24709811

Questions about this trial

What is this clinical trial studying?

A study testing brimonidine 0.15% in people with Glaucoma, run by Massachusetts Eye and Ear Infirmary at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 4 Apr 2017. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 27 Oct 2016). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Presence of Retinal Blood Flow Autoregulation (time frame: 8 weeks). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT01105065, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Apr 2017.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in