Clinical trial NCT01280110: The Effects of BAK on the Blood Aqueous Barrier of Pseudophakic Patients
Official title: The Effects of BAK on the Blood Aqueous Barrier of Pseudophakic Patients
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Dry Eye Syndromes
Keywords: dry eye
pseudophakia
cornea
lubricating drop
BAK
blood aqueous barrier
blood-retina barrier
Lead sponsor: University of Campinas, Brazil
Sponsor class: OTHER
Collaborators: name: Merck Sharp & Dohme LLC
First posted: 2011-01-20
Enrollment: 44
Sex: ALL
Minimum age (years): 18
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.

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.

Eligibility criteria: 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.

Primary outcomes:
measure: Aqueous Humor Flare
timeFrame: Baseline, 15 days and 30 days.
Secondary outcomes:
measure: Macular Thickness
timeFrame: Baseline, 15 days and 30 days.
Other outcomes:
Locations:
city: Campinas
country: Brazil
facility: Department of Ophthalmology, University of Campinas
state: SP
Study officials:
affiliation: Department of Ophthalmology, University of Campinas
name: Vital P Costa, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Baudouin C, Labbe A, Liang H, Pauly A, Brignole-Baudouin F. Preservatives in eyedrops: the good, the bad and the ugly. Prog Retin Eye Res. 2010 Jul;29(4):312-34. doi: 10.1016/j.preteyeres.2010.03.001. Epub 2010 Mar 17.
citation: Noecker RJ, Herrygers LA, Anwaruddin R. Corneal and conjunctival changes caused by commonly used glaucoma medications. Cornea. 2004 Jul;23(5):490-6. doi: 10.1097/01.ico.0000116526.57227.82.
citation: Ammar DA, Noecker RJ, Kahook MY. Effects of benzalkonium chloride-preserved, polyquad-preserved, and sofZia-preserved topical glaucoma medications on human ocular epithelial cells. Adv Ther. 2010 Nov;27(11):837-45. doi: 10.1007/s12325-010-0070-1. Epub 2010 Oct 7.