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The Effects of BAK on the Blood Aqueous Barrier of Pseudophakic Patients

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: NCT01280110
Recruitment Status : Completed
First Posted : January 20, 2011
Results First Posted : July 12, 2012
Last Update Posted : July 18, 2012
Merck Sharp & Dohme Corp.
Information provided by (Responsible Party):
Vital Paulino Costa, University of Campinas, Brazil

Brief Summary:

BAK is one of the most frequent preservatives in eye drops. BAK is a quaternary ammonium salt with surfactant qualities. It can be bacteriostatic or bactericidal depending on the concentrations used. It has been shown to be effective against most bacteria with a few exceptions, such as Pseudomonas aeruginosa, or picornaviruses. It as been widely used in eyedrops, nose sprays, hand and face washes, mouthwashes, spermicidal creams, and in various other cleaners, sanitizers, and disinfectants. BAK gained popularity when it was first introduced because it also enhances corneal penetration of some drugs by causing epithelial separation.

It is present in several ophthalmic formulations, including most of the antiglaucoma medications. If used chronically, BAK has been found to cause ocular surface changes, such as dry eye and punctuate keratitis. BAK has also been suggested to promote a break in the blood aqueous barrier, which may lead to undesirable consequences, such as uveitis and cystoid macular edema. However, this information is controversial. The purpose of this study is to evaluate the consequences of BAK on the blood-retinal and blood-aqueous barriers of pseudophakic patients receiving BAK-preserved lubricating drops.

Condition or disease Intervention/treatment Phase
Dry Eye Syndromes Drug: Hydroxypropylmethylcellulose Drug: Carboxymethylcellulose Phase 4

Detailed Description:

The primary hypothesis behind the study is that BAK may lead to a break in the blood-retina barrier in pseudophakic eyes, leading to an increase in macular thickness, compared to a non-BAK containing solution. The secondary hypothesis is that solutions containing BAK will increase the permeability of the blood aqueous barrier compared to non-BAK solutions. If the hypotheses are confirmed, they may serve as a contraindication to the use of BAK-preserved drops in pseudophakic eyes requiring chronic use of medications.

This is a prospective, randomized, examiner-masked, controlled study involving 44 pseudophakic eyes of 44 patients. Patients receiving any other eyedrop, with a previous history of uveitis, posterior capsule rupture or any other ophthalmic surgery will be excluded. Patients will be randomized to the use of a BAK-preserved lubricating drop or to the use of a non-preserved lubricating drop q.i.d for one month. Effects on the blood aqueous barrier will be objectively measured with a laser flare meter (Kowa, Japan) at baseline, 15 days and one month after inclusion. Patients will also have OCT images (Cirrus, Zeiss, USA) of the macula at the same time intervals to evaluate the possible effects on the blood-retina barrier. Macular thickness and the presence of cystoid macular edema will be evaluated at each time interval.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 44 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Investigator)
Primary Purpose: Treatment
Official Title: The Effects of BAK on the Blood Aqueous Barrier of Pseudophakic Patients
Study Start Date : March 2011
Actual Primary Completion Date : December 2011
Actual Study Completion Date : January 2012

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: Preserved (BAK 0.006%) lubricating drop
One group will receive preserved lubricating drops 4 times a day for 1 month.
Drug: Hydroxypropylmethylcellulose
22 patients will receive this lubricating drop 4 times a day for 1 month
Other Name: Retin Active

Active Comparator: Preservative-free lubricating drops
The second group will receive preservative-free lubricating drops 4 times a day for 1 month.
Drug: Carboxymethylcellulose
22 patients will receive this lubricating drop 4 times a day for 1 month.
Other Name: Optive UD

Primary Outcome Measures :
  1. Aqueous Humor Flare [ Time Frame: Baseline, 15 days and 30 days. ]
    Aqueous humor flare indicates the degree of a break in the blood-aqueous barrier. It is objectively measured with a Laser flare meter.

Secondary Outcome Measures :
  1. Macular Thickness [ Time Frame: Baseline, 15 days and 30 days. ]
    Macular thickness will be measured with an Optical coherence tomography (OCT). Measures 5% under the normal population according to the OCT software will be considered break in the blood-retina barrier.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Pseudophakic eyes that underwent cataract surgery at least 6 months before.

Exclusion Criteria:

  • Use of any eyedrop.
  • Other conditions associated with a break in the blood-aqueous or blood retina barrier (ie diabetes, ARMD, vasculitis, uveitis)
  • Previous history of cystoid macular edema.
  • Previous ocular surgery other than cataract surgery.

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): NCT01280110

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Department of Ophthalmology, University of Campinas
Campinas, SP, Brazil
Sponsors and Collaborators
University of Campinas, Brazil
Merck Sharp & Dohme Corp.
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Principal Investigator: Vital P Costa, MD Department of Ophthalmology, University of Campinas
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Responsible Party: Vital Paulino Costa, Professor of Ophthalmology, University of Campinas, Brazil Identifier: NCT01280110    
Other Study ID Numbers: VPC1
First Posted: January 20, 2011    Key Record Dates
Results First Posted: July 12, 2012
Last Update Posted: July 18, 2012
Last Verified: July 2012
Keywords provided by Vital Paulino Costa, University of Campinas, Brazil:
dry eye
lubricating drop
blood aqueous barrier
blood-retina barrier
Additional relevant MeSH terms:
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Dry Eye Syndromes
Eye Diseases
Lacrimal Apparatus Diseases
Carboxymethylcellulose Sodium
Gastrointestinal Agents