Purpose: To evaluate the efficacy and safety of 0.2% brimonidine eye drops given twice daily in normal tension glaucoma.
Patients and methods: Sixteen consecutive patients fulfilling eligibility criteria (glaucomatous optic neuropathy associated with visual field defect in at least one eye, intraocular pressure (IOP) < or = 18 mmHg (average of the two highest readings of the round-the-clock curve, including one reading at midnight in supine position), no prior glaucoma therapy, angle wide open, visual acuity 20/40 or better) were enrolled in this prospective, randomized, placebo-controlled clinical trial with crossover design, lasting 30 days for each treatment phase plus 15-day washout in between. Main outcome was IOP (average of the two highest readings of the round-the-clock curve).
Results: Mean IOP was significantly reduced by brimonidine (from 17.1 +/- 0.7 mm Hg to 13.9 +/- 2.2 mmHg, p<0.001 (paired Student t-test)). At the end of the 30-day brimonidine phase, 4 of 16 subjects showed a > or = 30% IOP decrease over baseline.
Conclusions: In the short term, 0.2% brimonidine eye drops can induce a significant IOP decrease in eyes with normal tension glaucoma.