A Randomized Trial of Brimonidine Versus Timolol in Preserving Visual Function: Results From the Low-pressure Glaucoma Treatment Study

doi:10.1016/j.ajo.2010.09.026

American Journal of Ophthalmology

Volume 151, Issue 4, April 2011, Pages 671-681

https://doi.org/10.1016/j.ajo.2010.09.026 Get rights and content

Purpose

To compare the alpha2-adrenergic agonist brimonidine tartrate 0.2% to the beta-adrenergic antagonist timolol maleate 0.5% in preserving visual function in low-pressure glaucoma.

Design

Randomized, double-masked, multicenter clinical trial.

Methods

Exclusion criteria included untreated intraocular pressure (IOP) >21 mm Hg, visual field mean deviation worse than −16 decibels, or contraindications to study medications. Both eyes received twice-daily monotherapy randomized in blocks of 7 (4 brimonidine to 3 timolol). Standard automated perimetry and tonometry were performed at 4-month intervals. Main outcome measure was field progression in either eye, defined as the same 3 or more points with a negative slope ≥−1 dB/year at P < 5%, on 3 consecutive tests, assessed by pointwise linear regression. Secondary outcome measures were progression based on glaucoma change probability maps (GCPM) of pattern deviation and the 3-omitting method for pointwise linear regression.

Results

Ninety-nine patients were randomized to brimonidine and 79 to timolol. Mean (± SE) months of follow-up for all patients was 30.0 ± 2. Statistically fewer brimonidine-treated patients (9, 9.1%) had visual field progression by pointwise linear regression than timolol-treated patients (31, 39.2%, log-rank 12.4, P = .001). Mean treated IOP was similar for brimonidine- and timolol-treated patients at all time points. More brimonidine-treated (28, 28.3%) than timolol-treated (9, 11.4%) patients discontinued study participation because of drug-related adverse events (P = .008). Similar differences in progression were observed when analyzed by GCPM and the 3-omitting method.

Conclusion

Low-pressure glaucoma patients treated with brimonidine 0.2% who do not develop ocular allergy are less likely to have field progression than patients treated with timolol 0.5%.

Section snippets

Methods

Methods are fully described elsewhere.¹⁵

Results

Recruitment¹⁵ was between April 28, 1998 and June 19, 2000, with 193 individuals assessed for enrollment (Figure 1). A total of 178 randomized participants were followed: 99 (55.6%) were allocated to brimonidine and 79 (44.4%) to timolol. There were no significant differences at baseline in demographics, ocular parameters, or systemic factors between the 2 treatment groups (Table 1).

Statistically more subjects assigned to brimonidine (36/99, 36.4%) dropped out prior to the year-1 examination

Discussion

Low-pressure glaucoma patients randomized to monotherapy with brimonidine were statistically less likely to have progressive visual field loss than those patients randomized to monotherapy with timolol, despite known similar IOP lowering.13, 14, 16, 24 Determination of field progression by pointwise linear regression required the same 3 or more individual test locations to be progressing on 3 consecutive examinations over an 8-month interval.²⁵ Therefore, the first detection of field

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Original articleA Randomized Trial of Brimonidine Versus Timolol in Preserving Visual Function: Results From the Low-pressure Glaucoma Treatment Study

Purpose

Design

Methods

Results

Conclusion

Section snippets

Methods

Results

Discussion

Lancet

Ophthalmology

Ophthalmology

Am J Ophthalmol

Clin Ther

Ophthalmology

Ophthalmology

Ophthalmology

Vision Res

Ophthalmology

Ophthalmology

Ophthalmology

Am J Ophthalmol

Exp Eye Res

Surv Ophthalmol

Ophthalmology

Number of ganglion cells in glaucoma eyes compared with threshold visual field tests in the same persons

Invest Ophthalmol Vis Sci

Normal-tension glaucoma

Relationship between intraocular pressure and primary open angle glaucoma among white and black AmericansThe Baltimore Eye Survey

Arch Ophthalmol

Reduction of intraocular pressure and glaucoma progression: results from the Early Manifest Glaucoma Trial

Arch Ophthalmol

The Ocular Hypertension Treatment Study: a randomized trial determines that topical ocular hypotensive medication delays or prevents the onset of primary open-angle glaucoma

Arch Ophthalmol

The Advanced Glaucoma Intervention Study (AGIS). 7: The relationship between control of intraocular pressure and visual field deterioration

Am J Ophthalmol

The effectiveness of intraocular pressure reduction in the treatment of normal-tension glaucoma

Am J Ophthalmol

Comparison of glaucomatous progression between untreated patients with normal-tension glaucoma and patients with therapeutically reduced intraocular pressures

Am J Ophthalmol

Experimental and clinical evidence for brimonidine as an optic nerve and retinal neuroprotective agent: An evidence-based review

Arch Ophthalmol

Regression analysis of visual field progression in low tension glaucoma

Br J Ophthalmol

Methodological variations in estimating apparent progressive visual field loss in clinical trials of glaucoma treatment

Arch Ophthalmol

Perimetric probability maps to separate change caused by glaucoma from that caused by cataract

Acta Ophthalmol Scand

Examination of different pointwise linear regression methods for determining visual field progression

Invest Ophthalmol Vis Sci

Original article
A Randomized Trial of Brimonidine Versus Timolol in Preserving Visual Function: Results From the Low-pressure Glaucoma Treatment Study