Study of Medical Treatment of Low-Pressure (Normal Tension) Glaucoma

• Status: Completed
• Trial end date: 2004-05-01
• Target enrollment: 0
• Participant gender: All

Summary

Low-pressure (normal tension) glaucoma is a type of open-angle glaucoma resulting in damage to the optic nerve and abnormalities of the visual field. Eye (intraocular) pressure in this type of glaucoma is not higher than that usually considered to be normal (less than 21 mmHg) for the eye. The present treatment of low-pressure glaucoma is also directed to lowering the "normal" eye pressure. Both medications in this study, brimonidine and timolol, lower eye pressure.

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.

• Phase: Phase 2
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Chicago Center for Vision Research
• Treatments: Brimonidine Tartrate; Timolol

Criteria

Inclusion Criteria:

• Age: 30 years or older.

• 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:

Either eye patient exclusion:

• 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.