Study of Medical Treatment of Low-Pressure (Normal Tension) Glaucoma
NCT ID: NCT00317577
Last Updated: 2006-04-25
Study Results
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Basic Information
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COMPLETED
PHASE2
160 participants
INTERVENTIONAL
1998-12-31
2004-05-31
Brief Summary
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Laboratory research over the past decade indicates the potential to treat glaucoma not only by lowering eye pressure, but with treatments aimed at the damage occurring at the optic nerve. One group of drugs, selective alpha2-adrenergic agonists, have been shown in laboratory animals to protect against the effects of nerve damage following local stroke. Brimonidine, one of the medications in the current study, is a selective alpha2-adrenergic agonist which protects against damage to optic nerve in animal models of glaucoma..
The hypothesis of the present study is that brimonidine eye drops provide protection to the damaged optic nerve independent of lowering eye pressure in patients with low-pressure glaucoma. This will be determined by (1) measuring eye pressure, (2) performing visual field examinations, and (3) examination of the optic nerve.
Detailed Description
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Current glaucoma treatment is directed to lowering eye pressure using medical therapy (eye drops), laser treatment, and/or surgery, to a level that stops progressive optic nerve damage. The efficacy of lowering eye pressure in LPG has been reported. Both protocol medical treatments, brimonidine and timolol, show similar efficacy to lower eye pressure.
Laboratory research over the past decade indicates the potential to manage glaucoma not only by lowering eye pressure, but with treatment modalities aimed at the damage occurring at the optic nerve. Possible therapies may include agents effective as neuronal protectants to increase or prolong the survival rate of injured retinal ganglion cells. Treatments could also be directed to the rescue of nerve fibers from secondary degeneration, as stimulants to expand dendritic fields, and to promote nerve regeneration or neural transplantation.
Selective α2-adrenergic agonists have been shown to have a neuroprotective effect in animal models of focal cerebral ischemia. Brimonidine is reported to protect the optic nerve and retinal ganglion cells from secondary degeneration following a partial crush lesion to the adult rat optic nerve. One molecular mechanism for this neuroprotection may relate to up-regulation of neuronal survival factors. In rats, systemic α2-adrenergic agonists induce basic fibroblast growth factor mRNA in the retina. Treatment with α2-agonists before and during constant light exposure reduces retinal photoreceptor degeneration in albino rats. Animal studies demonstrate that topical administration of brimonidine results in pharmacologic concentrations of drug in the vitreous (100-170 nM). Therefore, ocular dosing with brimonidine provides a route for drug delivery to the retina in amounts sufficient to bind and activate the α2-adrenoceptor and provide a neuroprotective effect.
The study hypothesis is to evaluate the ability of topical treatment with 0.2% brimonidine, a highly selective α2-adrenergic agonist, to impart neuroprotection to the damaged optic nerve in patients with LPG. Comparison is made to 0.5% timolol, a nonselective β-adrenergic antagonist, without reported neuroprotective properties. Patients will be randomly assigned to twice daily double-masked treatment with one of these drugs. Neuroprotection will be assessed by evaluation of automated static visual fields performed at 4 month intervals for 4 years of treatment.
Conditions
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Keywords
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Study Design
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RANDOMIZED
PARALLEL
TREATMENT
DOUBLE
Interventions
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brimonidine, timolol
Eligibility Criteria
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Inclusion Criteria
* Low-pressure glaucoma in at least one eye: untreated IOP \< 21 mmHg, glaucomatous field loss on Humphrey 24-2 perimetry, and optic disc cupping.
* Best corrected visual acuity at least 20/40 in at least one eye.
* At least two visual fields within the 6 months prior to enrollment.
* Phakic or pseudophakic (cataract surgery \> one year to enrollment) eye.
Exclusion Criteria
* Past history of confirmed treated or untreated applanation IOP \> 21 mmHg.
* Untreated IOP of \> 21 mmHg on diurnal curve on Study Day 0.
* Untreated IOP \> 4 mmHg difference between the two eyes.
* Extensive field damage: MD \> 15 dB or threat fixation in both hemi fields.
* Evidence of exfoliation or pigment dispersion.
* History of angle-closure or occludable gonioscopic anterior chamber angle.
* Prior filtration surgery.
* Prior laser iridotomy.
* Laser trabeculoplasty \< 6 months prior enrollment or for an IOP \> 21 mmHg.
* History of chronic inflammatory eye diseases (e.g., scleritis, uveitis).
* History or signs of intraocular trauma.
* Severe or potentially progressive retinal disease.
* Any abnormality preventing reliable applanation tonometry.
* History of hypersensitivity to study medications or their components.
* Current use of any ophthalmic, dermatologic or systemic steroid preparation.
* Therapy with another investigational agent within the past 30 days.
Single eye exclusion:
* Cataract surgery within the past year.
* Aphakia.
* Only sighted eye.
Concomitant conditions:
* Resting pulse \< 50 beats per minute.
* Unstable or uncontrolled cardiovascular, renal, or pulmonary disease.
* Recent heart attack or stroke.
* Women contemplating pregnancy, who are pregnant or are a nursing mother.
30 Years
ALL
No
Sponsors
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Chicago Center for Vision Research
OTHER
Principal Investigators
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Theodore Krupin, M.D.
Role: STUDY_CHAIR
Northwestern University Feinberg School of Medicine
Locations
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Little Rock Eye Clinic
Little Rock, Arkansas, United States
University of Florida
Gainesville, Florida, United States
Bascom Palmer Eye Institute
Palm Beach Gardens, Florida, United States
University Eye Specialists
Chicago, Illinois, United States
University of Chicago
Chicago, Illinois, United States
Wheaton Eye Clinic
Wheaton, Illinois, United States
Indiana University
Indianapolis, Indiana, United States
New York Eye & Ear Infirmary
New York, New York, United States
Scheie Eye Institute University of Pennsylvania
Philadelphia, Pennsylvania, United States
Wills Eye Hospital
Philadelphia, Pennsylvania, United States
Black Hills Regional Eye Institute
Rapid City, South Dakota, United States
Cullen Eye Institute Baylor University
Houston, Texas, United States
Countries
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References
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Krupin T, Liebmann JM, Greenfield DS, Rosenberg LF, Ritch R, Yang JW; Low-Pressure Glaucoma Study Group. The Low-pressure Glaucoma Treatment Study (LoGTS) study design and baseline characteristics of enrolled patients. Ophthalmology. 2005 Mar;112(3):376-85. doi: 10.1016/j.ophtha.2004.10.034.
Furlanetto RL, De Moraes CG, Teng CC, Liebmann JM, Greenfield DS, Gardiner SK, Ritch R, Krupin T; Low-Pressure Glaucoma Treatment Study Group. Risk factors for optic disc hemorrhage in the low-pressure glaucoma treatment study. Am J Ophthalmol. 2014 May;157(5):945-52. doi: 10.1016/j.ajo.2014.02.009. Epub 2014 Feb 7.
De Moraes CG, Liebmann JM, Greenfield DS, Gardiner SK, Ritch R, Krupin T; Low-pressure Glaucoma Treatment Study Group. Risk factors for visual field progression in the low-pressure glaucoma treatment study. Am J Ophthalmol. 2012 Oct;154(4):702-11. doi: 10.1016/j.ajo.2012.04.015. Epub 2012 Jul 25.
Krupin T, Liebmann JM, Greenfield DS, Ritch R, Gardiner S; Low-Pressure Glaucoma Study Group. A randomized trial of brimonidine versus timolol in preserving visual function: results from the Low-Pressure Glaucoma Treatment Study. Am J Ophthalmol. 2011 Apr;151(4):671-81. doi: 10.1016/j.ajo.2010.09.026. Epub 2011 Jan 22.
Other Identifiers
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CCVR-0020
Identifier Type: -
Identifier Source: org_study_id